National Library of Energy BETA

Sample records for mv millivolt napl

  1. Naples, Maine: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Naples, Maine: Energy Resources Jump to: navigation, search Equivalent URI DBpedia Coordinates 43.971739, -70.6092258 Show Map Loading map... "minzoom":false,"mappingservice":...

  2. Microsoft Word - DOE_RM_DM-#99768-v1-NAPL_Quarterly_Report_for...

    Office of Legacy Management (LM)

    ... remediation process, an overview of construction and operation activities for NAPL Area ... of planning activities for the construction of a similar treatment system at NAPL ...

  3. Microsoft Word - N0071600-NAPL-Oct to Dec.doc

    Office of Legacy Management (LM)

    ... remediation process, an overview of construction and operation activities for NAPL Area ... planning activities for the construction of a similar treatment system at NAPL ...

  4. Microsoft Word - N0074600-NAPL-Jan to March.doc

    Office of Legacy Management (LM)

    remediation process, an overview of construction and operation activities for NAPL Area ... of planning activities for the construction of a similar treatment system at NAPL ...

  5. Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation Paper presented at the Third International Conference on Oxidation and Reduction Technologies for Soil and Groundwater. October 2004, San Diego, California. Michael Butherus, David S. Ingle, Randall Juhlin, Joseph Daniel Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation (305.82 KB) More Documents &

  6. Microsoft Word - DOE_RM_DM-#350832-v1-NAPL_Quarterly_April-June...

    Office of Legacy Management (LM)

    ... completed the final conceptual design for Area B NAPL remediation in early ... of Non-Aqueous Phase Liquids at the Northeast Site (Area B Conceptual Design) (DOE 2004). ...

  7. Microsoft Word - DOE_RM_DM-#345139-v1-NAPL_Quarterly_Oct-Dec...

    Office of Legacy Management (LM)

    ... completed the final conceptual design for Area B NAPL remediation in early ... of Non-Aqueous Phase Liquids at the Northeast Site (Area B Conceptual Design) (DOE 2004). ...

  8. Microsoft Word - DOE_RM_DM-#100069-v1-NAPL_Quarterly_Oct-Dec...

    Office of Legacy Management (LM)

    ... completed the final conceptual design for Area B NAPL remediation in early ... of Non-Aqueous Phase Liquids at the Northeast Site (Area B Conceptual Design) (DOE 2004). ...

  9. Successful Field-Scale In Situ Thermal NAPL Remediation at the Young -

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Rainey STAR Center | Department of Energy Successful Field-Scale In Situ Thermal NAPL Remediation at the Young - Rainey STAR Center Successful Field-Scale In Situ Thermal NAPL Remediation at the Young - Rainey STAR Center Proceedings of the Fourth International Conference on Remediation of Chlorinated and Recalcitrant Compounds. May 2004, Monterey, California. Randall Juhlin, Michael Butherus, Joseph Daniel, David S. Ingle, Dr. Gorm Heron, Dr. Bruce McGee Successful Field-Scale In Situ

  10. Observation of 690 MV m^-1 Electron Accelerating Gradient with...

    Office of Scientific and Technical Information (OSTI)

    Observation of 690 MV m-1 Electron Accelerating Gradient with a Laser-Driven Dielectric Microstructure Citation Details In-Document Search Title: Observation of 690 MV m-1...

  11. M&V Guidelines: Measurement and Verification for Federal Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    M&V Guidelines: Measurement and Verification for Federal Energy Projects (Version 4.0) M&V Guidelines: Measurement and Verification for Federal Energy Projects (Version 4.0) ...

  12. M&V Guidelines: Measurement and Verification for Federal Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    M&V Guidelines: Measurement and Verification for Performance-Based Contracts Version 4.0 ... Management Program November 2015 FEMP M&V Guidelines 4.0 i ACKNOWLEDGMENTS ...

  13. M&V Guidelines: Measurement and Verification for Performance...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    You are here Home M&V Guidelines: Measurement and Verification for Performance-Based Contracts (Version 4.0) M&V Guidelines: Measurement and Verification for Performance-Based ...

  14. FEMP Seeking Public Comment on Draft M&V Guidelines

    Broader source: Energy.gov [DOE]

    FEMP is continuing its request for public comments on the Draft M&V Guidelines: Measurement and Verification for Performance-Based Contracts (Version 4.0).

  15. M&V Guidelines: Measurement and Verification for Federal Energy...

    Energy Savers [EERE]

    and Verification Protocol (IPMVP) Concepts and Options for Determining Energy and Water Savings Volume 1, April 2007. M&V Guidelines 3.0 FEMP ii Contents Section Page Section...

  16. Assessment of Automated Measurement and Verification (M&V) Methods

    SciTech Connect (OSTI)

    Granderson, Jessica; Touzani, Samir; Custodio, Claudine; Sohn, Michael; Fernandes, Samuel; Jump, David

    2015-07-01

    This report documents the application of a general statistical methodology to assess the accuracy of baseline energy models, focusing on its application to Measurement and Verification (M&V) of whole-building energy savings.

  17. In Situ Thermal NAPL Remediation at the Northeast Site Pinellas Environmental Restoration Project

    SciTech Connect (OSTI)

    Juhlin, R.; Butherus, M.

    2006-07-01

    The U.S. Department of Energy (DOE) is conducting thermal remediation to remove non-aqueous phase liquids (NAPLs) from the subsurface at the Northeast Site that is part of the Pinellas Environmental Restoration Project. The Northeast Site is located on the Young - Rainey Science, Technology, and Research (STAR) Center in Largo, Florida. The STAR Center was formerly a DOE facility. The NAPL remediation was performed at Area A and is currently being performed at Area B at the Northeast Site. The remediation at Area A was completed in 2003 and covered an area of 900 m{sup 2} (10,000 ft{sup 2}) and a depth of remediation that extended to 10.7 m (35 ft) below ground surface. Cleanup levels achieved were at or below maximum contaminant levels in almost all locations. The remediation project at Area B is ongoing and covers an area of 3,240 m{sup 2} (36,000 ft{sup 2}), a volume of 41,300 m (54,000 yd 3), and a depth of remediation to 12 m (40 ft) below ground surface. In addition, a portion of the subsurface under an occupied building in Area B is included in the remediation. The cleanup levels achieved from this remediation will be available in the Area B Final Report that will be posted on the DOE Office of Legacy Management web site (www.lm.doe.gov/land/sites/fl/ pinellas/pinellas.htm) in January 2007. Electrical resistive heating and steam were the chosen remediation methods at both areas. Lessons learned from the Area A remediation were incorporated into the Area B remediation and could benefit managers of similar remediation projects. (authors)

  18. State and Local Energy Savings Performance Contracting: Savings Measurement and Verification (M&V)

    Office of Energy Efficiency and Renewable Energy (EERE)

    State and Local Energy Savings Performance Contracting: Savings Measurement and Verification (M&V) Webinar.

  19. COMMISSIONING AND OPERATION OF THE CEBAF 100 MV CRYOMODULES

    SciTech Connect (OSTI)

    Allison, Trent; Davis, G; Drury, Michael; Harwood, Leigh; Hogan, John; Kimber, Andrew; Lahti, George; Merz, William; Nelson, Richard; Plawski, Tomasz; Seidman, David; Spata, Michael; Wilson, Michael

    2012-07-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of ten new 100 MV cryomodules and RF systems. The superconducting RF cavities are designed to operate CW at a maximum accelerating gradient of 19.3 MV/m. To support the higher gradients and higher Q{sub L} ({approx} 3 x 10{sup 7}), a new RF system has been developed and is being installed to power and control the cavities. The RF system employs digital control and 13 kW klystrons. Recently, two of these cryomodules and associated RF hardware and software have been installed and commissioned in the CEBAF accelerator. Electrons at linac currents up to 540 {micro}A have been successfully accelerated and used for nuclear physics experiments. This paper reports on the commissioning and operation of the RF system and cryomodules.

  20. M&V Guidelines: Measurement and Verification for Federal Energy Projects

    Broader source: Energy.gov [DOE]

    FEMP's standard procedures and guidelines for M&V for federal energy managers, procurement officials, and energy service providers.

  1. Measurement and Verification (M&V) Guidelines for Federal Energy Projects, V3.0

    SciTech Connect (OSTI)

    2008-06-11

    FEMP's standard procedures and guidelines for M&V for federal energy managers, procurement officials, and energy service providers.

  2. SU-E-T-221: Investigation of Lower Energy (< 6 MV) Photon Beams for Cancer Radiotherapy

    SciTech Connect (OSTI)

    Zhang, Y; Ming, X; Feng, Y; Zhou, L; Ahmad, M; Deng, J; Nguyen, K; Griffin, M

    2014-06-01

    Purpose: To study the potential applications of the lower energy (< 6MV) photon beams in the radiotherapeutic management of pediatric cancer and lung cancer patients. Methods: Photon beams of 2, 3, 4, 5 and 6MV were first simulated with EGS4/BEAM and then used for Monte-Carlo dose calculations. For four pediatric patients with abdominal and brain lesions, six 3D-conformal radiotherapy (3DCRT) plans were generated using single photon energy (2 to 6MV) or mixed energies (3 and 6MV). Furthermore, a virtual machine of 3 and 6MV was commissioned in a treatment planning system (TPS) based on Monte-Carlo simulated data. Three IMRT plans of a lung cancer patient were generated on this virtual machine. All plans were normalized to D95% of target dose for 6MV plan and then compared in terms of integral dose and OAR sparing. Results: For the four pediatric patients, the integral dose for the 2, 3, 4 and 5MV plans increased by 9%, 5%, 3.5%, 1.7%, respectively as compared to 6MV. Almost all OARs in the 2MV plan received more than 10% more doses than 6MV. Mixed energy 3DCRT plans were of the same quality as 6MV plans. For the lung IMRT plans, both the 3MV plan and the mixed beam plan showed better OAR sparing in comparison to 6MV plan. Specifically, the maximum and mean doses to the spinal cord in the mixed energy plan were lower by 21% and 16%, respectively. Conclusion: Single lower energy photon beam was found to be inferior to 6MV in the radiotherapy of pediatric patients and lung cancer patients when the integral doses and the doses to the OARs were considered. However, mixed energy plans combining low with high energy beams showed significant OAR sparing while maintaining the same PTV coverage. Investigation with more patient data is ongoing for further confirmation.

  3. M&V Guidelines: Measurement and Verification for Federal Energy Projects (Version 4.0)

    Broader source: Energy.gov [DOE]

    Document outlines the Federal Energy Management Program's standard procedures and guidelines for measurement and verification (M&V) for federal energy managers, procurement officials, and energy service providers.

  4. M&V Guidelines: Measurement and Verification for Performance-Based Contracts Version 4.0

    SciTech Connect (OSTI)

    2015-11-02

    Document outlines the Federal Energy Management Program's standard procedures and guidelines for measurement and verification (M&V) for federal energy managers, procurement officials, and energy service providers.

  5. Low-Z linac targets for low-MV gold nanoparticle radiation therapy

    SciTech Connect (OSTI)

    Tsiamas, P.; Mishra, P.; Berbeco, R. I.; Marcus, K.; Zygmanski, P. E-mail: Erno-Sajo@uml.edu; Cifter, F.; Sajo, E. E-mail: Erno-Sajo@uml.edu

    2014-02-15

    Purpose: To investigate the potential of low-Z/low-MV (low-Z) linac targets for gold nanoparticle radiotherapy (GNPT) and to determine the microscopic dose enhancement ratio (DER) due to GNP for the alternative beamlines. In addition, to evaluate the degradation of dose enhancement arising from the increased attenuation of x rays and larger skin dose in water for the low-MV beams compared to the standard linac. Methods: Monte Carlo simulations were used to compute dose and DER for various flattening-filter-free beams (2.5, 4, 6.5 MV). Target materials were beryllium, diamond, and tungsten-copper high-Z target. Target thicknesses were selected based on 20%, 60%, 70%, and 80% of the continuous slowing down approximation electron ranges for a given target material and energy. Evaluation of the microscopic DER was carried out for 100 nm GNP including the degradation factors due to beam attenuation. Results: The greatest increase in DER compared to the standard 6.5 MV linac was for a 2.5 MV Be-target (factor of ?2). Skin dose ranged from ?10% (Be, 6.5 MV-80%) to ?85% (Be, 2.5 MV-20%) depending on the target case. Attenuation of 2.5 MV beams at 22 cm was higher by ?75% compared with the standard beam. Taking into account the attenuation at 22 cm depth, the effective dose enhancement was up to ?60% above the DER of the high-Z target. For these cases the effective DER ranged between ?1.6 and 6 compared with the standard linac. Conclusions: Low-Z (2.5 MV) GNPT is possible even after accounting for greater beam attenuation for deep-seated tumors (22 cm) and the increased skin dose. Further, it can lead to significant sparing of normal tissue while simultaneously escalating the dose in the tumor cells.

  6. Construction of MV-6 Well Pad at the Central Nevada Test Area Completed

    Office of Energy Efficiency and Renewable Energy (EERE)

    A new groundwater monitoring/validation (MV) well was installed at the Central Nevada Test Area (CNTA) in September 2013. LM proposed this well to the Nevada Division of Environmental Protection ...

  7. Draft M&V Guidelines: Measurement and Verification for Federal Energy Projects (Version 4.0)

    Broader source: Energy.gov [DOE]

    Document describes the Federal Energy Management Program's (FEMP) standard procedures and guidelines for measurement and verification (M&V) for federal, state, and local government energy managers and procurement officials and utility and energy service providers.

  8. M&V Guidelines: Measurement and Verification for Federal Energy Projects (Version 3.0)

    Broader source: Energy.gov [DOE]

    Document describes the Federal Energy Management Program's (FEMP) standard procedures and guidelines for measurement and verification (M&V) for federal energy managers, procurement officials, and energy service providers.

  9. Measurement and verifiction (M&V) guidelines for federal energy projects

    SciTech Connect (OSTI)

    1996-02-01

    This document provides procedures and guidelines for quantifying the savings resulting from the installation of Energy Conservation Measures (ECMs) implemented with federal Energy Savings Performance Contracts (ESPCs) or task orders implemented under a federal IDIQ contract. The first section of this document provides an overview of measurement and verification (M&V) options and procedures. The second, third, and fourth sections provide standardized measurement and verification (M&V) methods for common types of ECMs.

  10. Generation of virtual monochromatic CBCT from dual kV/MV beam projections

    SciTech Connect (OSTI)

    Li, Hao; Liu, Bo; Yin, Fang-Fang

    2013-12-15

    Purpose: To develop a novel on-board imaging technique which allows generation of virtual monochromatic (VM) cone-beam CT (CBCT) with a selected energy from combined kilovoltage (kV)/megavoltage (MV) beam projections. Methods: With the current orthogonal kV/MV imaging hardware equipped in modern linear accelerators, both MV projections (from gantry angle of 0°–100°) and kV projections (90°–200°) were acquired as gantry rotated a total of 110°. A selected range of overlap projections between 90° to 100° were then decomposed into two material projections using experimentally determined parameters from orthogonally stacked aluminum and acrylic step-wedges. Given attenuation coefficients of aluminum and acrylic at a predetermined energy, one set of VM projections could be synthesized from two corresponding sets of decomposed projections. Two linear functions were generated using projection information at overlap angles to convert kV and MV projections at nonoverlap angles to approximate VM projections for CBCT reconstruction. The contrast-to-noise ratios (CNRs) were calculated for different inserts in VM CBCTs of a CatPhan phantom with various selected energies and compared with those in kV and MV CBCTs. The effect of overlap projection number on CNR was evaluated. Additionally, the effect of beam orientation was studied by scanning the CatPhan sandwiched with two 5 cm solid-water phantoms on both lateral sides and an electronic density phantom with two metal bolt inserts. Results: Proper selection of VM energy [30 and 40 keV for low-density polyethylene (LDPE), polymethylpentene, 2 MeV for Delrin] provided comparable or even better CNR results as compared with kV or MV CBCT. An increased number of overlap kV and MV projection demonstrated only marginal improvements of CNR for different inserts (with the exception of LDPE) and therefore one projection overlap was found to be sufficient for the CatPhan study. It was also evident that the optimal CBCT image

  11. Hyaluronan synthase 3 (HAS3) overexpression downregulates MV3 melanoma cell proliferation, migration and adhesion

    SciTech Connect (OSTI)

    Takabe, Piia; Bart, Geneviève; Ropponen, Antti; Rilla, Kirsi; Tammi, Markku; Tammi, Raija; Pasonen-Seppänen, Sanna

    2015-09-10

    Malignant skin melanoma is one of the most deadly human cancers. Extracellular matrix (ECM) influences the growth of malignant tumors by modulating tumor cells adhesion and migration. Hyaluronan is an essential component of the ECM, and its amount is altered in many tumors, suggesting an important role for hyaluronan in tumorigenesis. Nonetheless its role in melanomagenesis is not understood. In this study we produced a MV3 melanoma cell line with inducible expression of the hyaluronan synthase 3 (HAS3) and studied its effect on the behavior of the melanoma cells. HAS3 overexpression expanded the cell surface hyaluronan coat and decreased melanoma cell adhesion, migration and proliferation by cell cycle arrest at G1/G0. Melanoma cell migration was restored by removal of cell surface hyaluronan by Streptomyces hyaluronidase and by receptor blocking with hyaluronan oligosaccharides, while the effect on cell proliferation was receptor independent. Overexpression of HAS3 decreased ERK1/2 phosphorylation suggesting that inhibition of MAP-kinase signaling was responsible for these suppressive effects on the malignant phenotype of MV3 melanoma cells. - Highlights: • Inducible HAS3-MV3 melanoma cell line was generated using Lentiviral transduction. • HAS3 overexpression inhibits MV3 cell migration via hyaluronan–receptor interaction. • HAS3 overexpression decreases MV3 melanoma cell proliferation and adhesion. • ERK1/2 phosphorylation is downregulated by 50% in HAS3 overexpressing cells. • The results suggest that hyaluronan has anti-cancer like effects in melanoma.

  12. Real-time automatic fiducial marker tracking in low contrast cine-MV images

    SciTech Connect (OSTI)

    Lin, Wei-Yang; Lin, Shu-Fang; Yang, Sheng-Chang; Liou, Shu-Cheng; Nath, Ravinder; Liu Wu

    2013-01-15

    Purpose: To develop a real-time automatic method for tracking implanted radiographic markers in low-contrast cine-MV patient images used in image-guided radiation therapy (IGRT). Methods: Intrafraction motion tracking using radiotherapy beam-line MV images have gained some attention recently in IGRT because no additional imaging dose is introduced. However, MV images have much lower contrast than kV images, therefore a robust and automatic algorithm for marker detection in MV images is a prerequisite. Previous marker detection methods are all based on template matching or its derivatives. Template matching needs to match object shape that changes significantly for different implantation and projection angle. While these methods require a large number of templates to cover various situations, they are often forced to use a smaller number of templates to reduce the computation load because their methods all require exhaustive search in the region of interest. The authors solve this problem by synergetic use of modern but well-tested computer vision and artificial intelligence techniques; specifically the authors detect implanted markers utilizing discriminant analysis for initialization and use mean-shift feature space analysis for sequential tracking. This novel approach avoids exhaustive search by exploiting the temporal correlation between consecutive frames and makes it possible to perform more sophisticated detection at the beginning to improve the accuracy, followed by ultrafast sequential tracking after the initialization. The method was evaluated and validated using 1149 cine-MV images from two prostate IGRT patients and compared with manual marker detection results from six researchers. The average of the manual detection results is considered as the ground truth for comparisons. Results: The average root-mean-square errors of our real-time automatic tracking method from the ground truth are 1.9 and 2.1 pixels for the two patients (0.26 mm/pixel). The

  13. Metal artifact correction for x-ray computed tomography using kV and selective MV imaging

    SciTech Connect (OSTI)

    Wu, Meng; Keil, Andreas; Constantin, Dragos; Star-Lack, Josh; Zhu, Lei; Fahrig, Rebecca

    2014-12-15

    Purpose: The overall goal of this work is to improve the computed tomography (CT) image quality for patients with metal implants or fillings by completing the missing kilovoltage (kV) projection data with selectively acquired megavoltage (MV) data that do not suffer from photon starvation. When both of these imaging systems, which are available on current radiotherapy devices, are used, metal streak artifacts are avoided, and the soft-tissue contrast is restored, even for regions in which the kV data cannot contribute any information. Methods: Three image-reconstruction methods, including two filtered back-projection (FBP)-based analytic methods and one iterative method, for combining kV and MV projection data from the two on-board imaging systems of a radiotherapy device are presented in this work. The analytic reconstruction methods modify the MV data based on the information in the projection or image domains and then patch the data onto the kV projections for a FBP reconstruction. In the iterative reconstruction, the authors used dual-energy (DE) penalized weighted least-squares (PWLS) methods to simultaneously combine the kV/MV data and perform the reconstruction. Results: The authors compared kV/MV reconstructions to kV-only reconstructions using a dental phantom with fillings and a hip-implant numerical phantom. Simulation results indicated that dual-energy sinogram patch FBP and the modified dual-energy PWLS method can successfully suppress metal streak artifacts and restore information lost due to photon starvation in the kV projections. The root-mean-square errors of soft-tissue patterns obtained using combined kV/MV data are 10–15 Hounsfield units smaller than those of the kV-only images, and the structural similarity index measure also indicates a 5%–10% improvement in the image quality. The added dose from the MV scan is much less than the dose from the kV scan if a high efficiency MV detector is assumed. Conclusions: The authors have shown that it

  14. Theoretical investigation of the design and performance of a dual energy (kV and MV) radiotherapy imager

    SciTech Connect (OSTI)

    Liu, Langechuan; Antonuk, Larry E. El-Mohri, Youcef; Zhao, Qihua; Jiang, Hao

    2015-04-15

    Purpose: In modern radiotherapy treatment rooms, megavoltage (MV) portal imaging and kilovoltage (kV) cone-beam CT (CBCT) imaging are performed using various active matrix flat-panel imager (AMFPI) designs. To expand the clinical utility of MV and kV imaging, MV AMFPIs incorporating thick, segmented scintillators and, separately, kV imaging using a beams eye view geometry have been investigated by a number of groups. Motivated by these previous studies, it is of interest to explore to what extent it is possible to preserve the benefits of kV and MV imaging using a single AMFPI design, given the considerably different x ray energy spectra used for kV and MV imaging. In this paper, considerations for the design of such a dual energy imager are explored through examination of the performance of a variety of hypothetical AMFPIs based on x ray converters employing segmented scintillators. Methods: Contrast, noise, and contrast-to-noise ratio performances were characterized through simulation modeling of CBCT imaging, while modulation transfer function, Swank factor, and signal performance were characterized through simulation modeling of planar imaging. The simulations were based on a previously reported hybrid modeling technique (accounting for both radiation and optical effects), augmented through modeling of electronic additive noise. All designs employed BGO scintillator material with thicknesses ranging from 0.25 to 4 cm and element-to-element pitches ranging from 0.508 to 1.016 mm. A series of studies were performed under both kV and MV imaging conditions to determine the most advantageous imager configuration (involving front or rear x ray illumination and use of a mirror or black reflector), converter design (pitch and thickness), and operating mode (pitch-binning combination). Results: Under the assumptions of the present study, the most advantageous imager design was found to employ rear illumination of the converter in combination with a black reflector

  15. Tracking tumor boundary in MV-EPID images without implanted markers: A feasibility study

    SciTech Connect (OSTI)

    Zhang, Xiaoyong Homma, Noriyasu; Ichiji, Kei; Takai, Yoshihiro; Yoshizawa, Makoto

    2015-05-15

    Purpose: To develop a markerless tracking algorithm to track the tumor boundary in megavoltage (MV)-electronic portal imaging device (EPID) images for image-guided radiation therapy. Methods: A level set method (LSM)-based algorithm is developed to track tumor boundary in EPID image sequences. Given an EPID image sequence, an initial curve is manually specified in the first frame. Driven by a region-scalable energy fitting function, the initial curve automatically evolves toward the tumor boundary and stops on the desired boundary while the energy function reaches its minimum. For the subsequent frames, the tracking algorithm updates the initial curve by using the tracking result in the previous frame and reuses the LSM to detect the tumor boundary in the subsequent frame so that the tracking processing can be continued without user intervention. The tracking algorithm is tested on three image datasets, including a 4-D phantom EPID image sequence, four digitally deformable phantom image sequences with different noise levels, and four clinical EPID image sequences acquired in lung cancer treatment. The tracking accuracy is evaluated based on two metrics: centroid localization error (CLE) and volume overlap index (VOI) between the tracking result and the ground truth. Results: For the 4-D phantom image sequence, the CLE is 0.23 0.20 mm, and VOI is 95.6% 0.2%. For the digital phantom image sequences, the total CLE and VOI are 0.11 0.08 mm and 96.7% 0.7%, respectively. In addition, for the clinical EPID image sequences, the proposed algorithm achieves 0.32 0.77 mm in the CLE and 72.1% 5.5% in the VOI. These results demonstrate the effectiveness of the authors proposed method both in tumor localization and boundary tracking in EPID images. In addition, compared with two existing tracking algorithms, the proposed method achieves a higher accuracy in tumor localization. Conclusions: In this paper, the authors presented a feasibility study of tracking tumor

  16. First Demonstration of Combined kV/MV Image-Guided Real-Time Dynamic Multileaf-Collimator Target Tracking

    SciTech Connect (OSTI)

    Cho, Byungchul Poulsen, Per R.; Sloutsky, Alex; Sawant, Amit; Keall, Paul J.

    2009-07-01

    Purpose: For intrafraction motion management, a real-time tracking system was developed by combining fiducial marker-based tracking via simultaneous kilovoltage (kV) and megavoltage (MV) imaging and a dynamic multileaf collimator (DMLC) beam-tracking system. Methods and Materials: The integrated tracking system employed a Varian Trilogy system equipped with kV/MV imaging systems and a Millennium 120-leaf MLC. A gold marker in elliptical motion (2-cm superior-inferior, 1-cm left-right, 10 cycles/min) was simultaneously imaged by the kV and MV imagers at 6.7 Hz and segmented in real time. With these two-dimensional projections, the tracking software triangulated the three-dimensional marker position and repositioned the MLC leaves to follow the motion. Phantom studies were performed to evaluate time delay from image acquisition to MLC adjustment, tracking error, and dosimetric impact of target motion with and without tracking. Results: The time delay of the integrated tracking system was {approx}450 ms. The tracking error using a prediction algorithm was 0.9 {+-} 0.5 mm for the elliptical motion. The dose distribution with tracking showed better target coverage and less dose to surrounding region over no tracking. The failure rate of the gamma test (3%/3-mm criteria) was 22.5% without tracking but was reduced to 0.2% with tracking. Conclusion: For the first time, a complete tracking system combining kV/MV image-guided target tracking and DMLC beam tracking was demonstrated. The average geometric error was less than 1 mm, and the dosimetric error was negligible. This system is a promising method for intrafraction motion management.

  17. Design of a 7-MV Linear Transformer Driver (LTD) for down-hole flash x-ray radiography.

    SciTech Connect (OSTI)

    Cordova, Steve Ray; Welch, Dale Robert; Oliver, Bryan Velten; Rose, David Vincent; Johnson, David Lee; Bruner, Nichelle Lee; Leckbee, Joshua J.

    2008-09-01

    Pulsed power driven flash x-ray radiography is a valuable diagnostic for subcritical experiments at the Nevada Test Site. The existing dual-axis Cygnus system produces images using a 2.25 MV electron beam diode to produce intense x-rays from a small source. Future hydrodynamic experiments will likely use objects with higher areal mass, requiring increased x-ray dose and higher voltages while maintaining small source spot size. A linear transformer driver (LTD) is a compact pulsed power technology with applications ranging from pulsed power flash x-ray radiography to high current Z-pinch accelerators. This report describes the design of a 7-MV dual-axis system that occupies the same lab space as the Cygnus accelerators. The work builds on a design proposed in a previous report [1]. This new design provides increased diode voltage from a lower impedance accelerator to improve coupling to low impedance diodes such as the self magnetic pinch (SMP) diode. The design also improves the predicted reliability by operating at a lower charge voltage and removing components that have proven vulnerable to failure. Simulations of the new design and experimental results of the 1-MV prototype are presented.

  18. Performance and Applications of the first HVE 5MV Tandetron{sup TM} at the University of Madrid

    SciTech Connect (OSTI)

    Mous, D.J.W.; Gottdang, A.; Haitsma, R.G.; Garcia Lopez, G.; Climent-Font, A.; Agullo-Lopez, F.; Boerma, D.O.

    2003-08-26

    The first HVE Tandetron{sup TM} with a nominal terminal voltage of 5 MV has been put into operation at the Universidad Autonoma de Madrid (Spain) as part of their new IBA facility. The accelerator features a coaxial structure in which the all-solid-state power supply is constructed around the high-energy acceleration tube, thereby avoiding the T-shaped tank that has characterized the HVE Tandetrons{sup TM} so far. The new IBA facility covers a number of different ion beam analysis techniques including ERD using heavy-element time-of-flight, RBS, as well as an external micro-beam for PIXE. During installation, tests have shown a stable terminal voltage of 5.5 MV. The terminal voltage ripple was deduced to be below 6 x 10-6 (RMS) for terminal voltages above 800 kV. Terminal voltage undershoot was measured to be 1.4 x 10-3 for a {approx}1 kW beam at 3 MV and recovered to 1 x 10-4 within 800 ms. IBA experiments that require low energy hydrogen beams are supported by a stable terminal voltage down to 100 kV.

  19. NAPL Calculator - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Programs http://nnsa.energy.gov printed copies are uncontrolled SUPPLEMENTAL DIRECTIVE Approved: 2-25-16 DEFENSE PROGRAMS BUSINESS PROCESS SYSTEM (DPBPS) NATIONAL NUCLEAR SECURITY ADMINISTRATION Office of Defense Programs NNSA SD 452.3-1A THIS PAGE INTENTIONALLY LEFT BLANK NNSA SD 452.3-1A 1 2-25-16 DEFENSE PROGRAMS BUSINESS PROCESS SYSTEM 1. PURPOSE. This supplemental directive (SD) establishes the Defense Programs Business Process System (DPBPS) Portal as the mechanism for implementing DOE

  20. Mapping the genome of meta-generalized gradient approximation density functionals: The search for B97M-V

    SciTech Connect (OSTI)

    Mardirossian, Narbe; Head-Gordon, Martin

    2015-02-21

    A meta-generalized gradient approximation density functional paired with the VV10 nonlocal correlation functional is presented. The functional form is selected from more than 10{sup 10} choices carved out of a functional space of almost 10{sup 40} possibilities. Raw data come from training a vast number of candidate functional forms on a comprehensive training set of 1095 data points and testing the resulting fits on a comprehensive primary test set of 1153 data points. Functional forms are ranked based on their ability to reproduce the data in both the training and primary test sets with minimum empiricism, and filtered based on a set of physical constraints and an often-overlooked condition of satisfactory numerical precision with medium-sized integration grids. The resulting optimal functional form has 4 linear exchange parameters, 4 linear same-spin correlation parameters, and 4 linear opposite-spin correlation parameters, for a total of 12 fitted parameters. The final density functional, B97M-V, is further assessed on a secondary test set of 212 data points, applied to several large systems including the coronene dimer and water clusters, tested for the accurate prediction of intramolecular and intermolecular geometries, verified to have a readily attainable basis set limit, and checked for grid sensitivity. Compared to existing density functionals, B97M-V is remarkably accurate for non-bonded interactions and very satisfactory for thermochemical quantities such as atomization energies, but inherits the demonstrable limitations of existing local density functionals for barrier heights.

  1. Aberration corrected 1.2-MV cold field-emission transmission electron microscope with a sub-50-pm resolution

    SciTech Connect (OSTI)

    Akashi, Tetsuya; Takahashi, Yoshio; Tanigaki, Toshiaki Shimakura, Tomokazu; Kawasaki, Takeshi; Furutsu, Tadao; Shinada, Hiroyuki; Osakabe, Nobuyuki; Mller, Heiko; Haider, Maximilian; Tonomura, Akira

    2015-02-16

    Atomic-resolution electromagnetic field observation is critical to the development of advanced materials and to the unveiling of their fundamental physics. For this purpose, a spherical-aberration corrected 1.2-MV cold field-emission transmission electron microscope has been developed. The microscope has the following superior properties: stabilized accelerating voltage, minimized electrical and mechanical fluctuation, and coherent electron emission. These properties have enabled to obtain 43-pm information transfer. On the bases of these performances, a 43-pm resolution has been obtained by correcting lens aberrations up to the third order. Observations of GaN [411] thin crystal showed a projected atomic locations with a separation of 44?pm.

  2. Fundamental science investigations to develop a 6-MV laser triggered gas switch for ZR: first annual report.

    SciTech Connect (OSTI)

    Warne, Larry Kevin; Van Den Avyle, James A.; Lehr, Jane Marie; Rose, David; Krompholz, Hermann G.; Vela, Russell; Jorgenson, Roy Eberhardt; Timoshkin, Igor (University of Strathclyde, Glasgow, Scotland); Woodworth, Joseph Ray; Prestwich, Kenneth Randel (Voss Scientific, Albuquerque, NM); Krile, John; Given, Martin (University of Strathclyde, Glasgow, Scotland); McKee, G. Randall; Rosenthal, Stephen Edgar; Struve, Kenneth William; Welch, Dale Robert (Voss Scientific, Albuquerque, NM); Benwell, Andrew L. (University of Missouri-Columbia, Columbia, Missouri); Kovaleski, Scott; LeChien, Keith, R.; Johnson, David (Titan Pulse Sciences Division); Fouracre, R.A. (University of Strathclyde, Glasgow, Scotland); Yeckel, Chris (University of Missouri-Columbia, Columbia, Missouri); Wakeland, Peter Eric; Miller, A. R. (Titan Pulse Sciences Division); Hodge, Keith Conquest (Ktech Corporation, Albuquerque, NM); Pasik, Michael Francis; Savage, Mark Edward; Maenchen, John Eric; Curry, Randy D.; Feltz, Greg; Bliss, David Emery; MacGregor, Scott (University of Strathclyde, Glasgow, Scotland); Corley, J. P. (Ktech Corporation, Albuquerque, NM); Anaya, Victor (Ktech Corporation, Albuquerque, NM); Wallace, Zachariah (Ktech Corporation, Albuquerque, NM); Thoma, Carsten (Voss Scientific, Albuquerque, NM); Neuber, Andreas. (Texas Tech University, Lubbock, TX)

    2007-03-01

    In October 2005, an intensive three-year Laser Triggered Gas Switch (LTGS) development program was initiated to investigate and solve observed performance and reliability issues with the LTGS for ZR. The approach taken has been one of mission-focused research: to revisit and reassess the design, to establish a fundamental understanding of LTGS operation and failure modes, and to test evolving operational hypotheses. This effort is aimed toward deploying an initial switch for ZR in 2007, on supporting rolling upgrades to ZR as the technology can be developed, and to prepare with scientific understanding for the even higher voltage switches anticipated needed for future high-yield accelerators. The ZR LTGS was identified as a potential area of concern quite early, but since initial assessments performed on a simplified Switch Test Bed (STB) at 5 MV showed 300-shot lifetimes on multiple switch builds, this component was judged acceptable. When the Z{sub 20} engineering module was brought online in October 2003 frequent flashovers of the plastic switch envelope were observed at the increased stresses required to compensate for the programmatically increased ZR load inductance. As of October 2006, there have been 1423 Z{sub 20} shots assessing a variety of LTGS designs. Numerous incremental and fundamental switch design modifications have been investigated. As we continue to investigate the LTGS, the basic science of plastic surface tracking, laser triggering, cascade breakdown, and optics degradation remain high-priority mission-focused research topics. Significant progress has been made and, while the switch does not yet achieve design requirements, we are on the path to develop successively better switches for rolling upgrade improvements to ZR. This report summarizes the work performed in FY 2006 by the large team. A high-level summary is followed by detailed individual topical reports.

  3. TH-E-17A-11: Tracking Tumors Boundary in MV Image Sequences for Image-Guided Radiation Therapy

    SciTech Connect (OSTI)

    Zhang, X; Homma, N; Ichiji, K; Abe, M; Sugita, N; Yoshizawa, M; Narita, Y; Takai, Y

    2014-06-15

    Purpose: To develop a level set method (LSM)-based algorithm to track the tumors boundary in MV image sequences for image-guided radiation therapy (IGRT). Method: Four MV image sequences, each of which consists of 100 frames at frame rate of 7.5 Hz, are acquired by using the electronic portal imaging device (EPID) (Varian Medical Systems, Pal Alto, USA) during the treatment of lung cancer. In the first frame of each sequence, we roughly delineate an initial contour of the target tumor by hand. Using a LSM-based algorithm, the initial contour can automatically shape itself to fit the tumor, and eventually detect the tumors boundary. We then employ the tumors boundary obtained from the previous frame as the initial contour in the subsequent frame, so that the LSM-based method can drive this initial contour to the tumors boundary quickly and fulfill a tracking task. Results: The proposed method has been evaluated on four MV image sequences. The mean tracking errors were 0.23, 0.29, 0.37, and 1.18 mm, and their corresponding standard deviations were 0.97, 0.75, 1.2 and 1.48 mm, respectively. Conclusion: Compared with conventional tumor tracking techniques, the proposed system is capable not only of tracking the tumors position, but also of detecting the tumors boundary varying with the respiration during the treatment. Considering current radiation therapy technique, for example, dynamical multi-leaf collimator (DMLC) has been widely applied in clinical treatment, this study indicates the potential for significant accuracy improvement in radiation therapy. This work was partially supported by a research grant from Varian Medical Systems (Palo Alto, California)

  4. SU-E-T-322: The Evaluation of the Gafchromic EBT3 Film in Low Dose 6 MV X-Ray Beams with Different Scanning Modes

    SciTech Connect (OSTI)

    Lee, H; Sung, J; Yoon, M; Kim, D; Chung, W

    2014-06-01

    Purpose: We have evaluated the response of the Gafchromic EBT3 film in low dose for 6 MV x-ray beams with two scanning modes, the reflection scanning mode and the transmission scanning mode. Methods: We irradiated the Gafcromic EBT3 film using a 60 degree enhanced dynamic wedge (EDW) with 6 MV x-ray beams from Clinac iX Linear accelerator (Varian Medical Systems, Palo Alto, CA). The irradiated Gafchromic EBT3 film was scanned with different scanning modes, the reflection scanning mode and the transmission scanning mode. The scanned Gafchromic EBT3 film was analyzed with MATLAB. Results: When 7.2 cGy was irradiated to the Gafchromic EBT3 film, the uncertainty was 0.54 cGy with reflection scanning mode and was 0.88 cGy with transmission scanning mode. When 24 cGy was irradiated to the Gafchromic EBT3 film, the uncertainty was similar to the case of 7.2 cGy irradiation showing 0.51 cGy of uncertainty with reflection scanning mode and 0.87 cGy of uncertainty with transmission scanning mode. The result suggests that the reflection mode should be used in Gafchromic EBT3 film for low irradiation. Conclusion: The result suggests that the reflection mode should be used in Gafchromic EBT3 film for low irradiation.

  5. SU-E-T-175: Evaluation of the Relative Output Ratio for Collimator Jaw and MLC Defined Small Static 6MV Photon Fields

    SciTech Connect (OSTI)

    Cho, G; Thwaites, D

    2014-06-01

    Purpose: To evaluate relative output ratio of collimator jaw and MLC defined small photon fields. Methods: Relative output ratios were measured using Gafchromic EBT3 film for a 6 MV photon beam on a Novalis Tx with HD120 MLC. Beam collimation was achieved by the jaws for 1.0 cm and 3.0 cm and MLC defined square field sizes between 0.5 cm and 1.0 cm with varying jaw settings between 2.0 and 4.0 cm. Film pieces were exposed to 4 Gy. Experiments were repeated with each session consisting of five consecutive exposures for the given MLC and/or jaw collimation and with the MLC and the jaws reset for each exposure. Films were scanned using EPSON 10000XL flatbed scanner approximately 24 hours after exposure in 48 bit RGB format at 150 dpi. Film calibration data were corrected for daily linac output variations. Doses were evaluated using the green channel with square ROI sizes of 0.1 – 0.6 cm. Converted doses were normalised for output ratio calculation using the 3.0 cm field as a machine specific reference field size. Mean output ratio and coefficient of variation (CV) were calculated for each experimental session. Results: For the Novalis 6 MV photon beam the output ratios between 0.719 and 0.872 have been measured for the jaw/MLC combinations tested. For a jaw setting of 4.0 cm field, the mean CV of the output ratios increased from 0.77% to 1.48% with decreasing MLC field size from 1.0 cm to 0.5 cm. For a nominal MLC 1.0 cm field, the CV increased to 1.00% from 0.77% with reducing jaw field size from 4.0 cm to 2.0 cm. Conclusion: The relative output ratio and the associated CV were dependent on the collimator jaw and MLC settings. The field size dependent CV showed similar trends to those reported in the literature.

  6. Metal Buildings M&V

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Reference Slides A&S Building Systems American Buildings Architectural Testing Atlas Bolt & Screw Behlen Manufacturing Butler Manufacturing Building Research Systems Kirby ...

  7. Ab initio structures of As{sub m}V complexes and the simulation of Rutherford backscattering channeling spectra in heavily As-doped crystalline silicon

    SciTech Connect (OSTI)

    Satta, Alessandra; Albertazzi, Eros; Lulli, Giorgio; Colombo, Luciano

    2005-12-15

    Geometrical models of neutral single vacancy-arsenic complexes are determined from first principles and used for atomistic simulation of Rutherford backscattering channeling (RBS-C) spectra in heavily As-doped crystalline silicon, both with and without compensating Si self-interstitials. The goal is to investigate whether the relaxation patterns of complexes containing different numbers (from 1 to 4) of As atoms can be used as a fingerprint in structural analysis by conventional RBS-C. Simulation of RBS-C spectra in million-atoms supercells containing a population of As{sub m}V, show the off-lattice displacement of the Si atoms neighboring the vacancy, due to Jahn-Teller effect. On the other side, As displacement is found to be similar in all clusters investigated. The present results suggest that in the case of samples equilibrated at high temperature, the lack of any significant disorder of Si atoms is consistent with the hypothesis of electrically inactive As being in the form of either As{sub 3}V or As{sub 4}V complexes.

  8. Fiducial marker and marker-less soft-tissue detection using fast MV fluoroscopy on a new generation EPID: Investigating the influence of pulsing artifacts and artifact suppression techniques

    SciTech Connect (OSTI)

    Poels, Kenneth Verellen, Dirk; Van de Vondel, Iwein; El Mazghari, Rafik; De Ridder, Mark; Depuydt, Tom

    2014-10-15

    Purpose: Because frame rates on current clinical available electronic portal imaging devices (EPIDs) are limited to 7.5 Hz, a new commercially available PerkinElmer EPID (XRD 1642 AP19) with a maximum frame rate of 30 Hz and a new scintillator (Kyokko PI200) with improved sensitivity (light output) for megavolt (MV) irradiation was evaluated. In this work, the influence of MV pulse artifacts and pulsing artifact suppression techniques on fiducial marker and marker-less detection of a lung lesion was investigated, because target localization is an important component of uncertainty in geometrical verification of real-time tumor tracking. Methods: Visicoil markers with a diameter of 0.05 and 0.075 cm were used for MV marker tracking with a frame rate of, respectively, 7.5, 15, and 30 Hz. A 30 Hz readout of the detector was obtained by a 2 2 pixel binning, reducing spatial resolution. Static marker detection was conducted in function of increasing phantom thickness. Additionally, marker-less tracking was conducted and compared with the ground-truth fiducial marker motion. Performance of MV target detection was investigated by comparing the least-square sine wave fit of the detected marker positions with the predefined sine wave motion. For fiducial marker detection, a Laplacian-of-Gaussian enhancement was applied after which normalized cross correlation was used to find the most probable marker position. Marker-less detection was performed by using the scale and orientation adaptive mean shift tracking algorithm. For each MV fluoroscopy, a free running (FR-nF) (ignoring MV pulsing during readout) acquisition mode was compared with two acquisition modes intending to reduce MV pulsing artifacts, i.e., combined wavelet-FFT filtering (FR-wF) and electronic readout synchronized with respect to MV pulses. Results: A 0.05 cm Visicoil marker resulted in an unacceptable root-mean square error (RMSE) > 0.2 cm with a maximum frame rate of 30 Hz during FR-nF readout. With a

  9. Final Report Northeast Site Area B NAPL Remediation Project

    Office of Legacy Management (LM)

    ... In order to seal the "gap" between the edge of asphalt and top of the geomembrane, a 1-inch thick cement- slurry "plug" was placed on top of the membrane. 2.4.4 Abandonment After ...

  10. Northeast Site Area A NAPL Remediation Final Report.doc

    Office of Legacy Management (LM)

    by U.S. Department of Energy Grand Junction Office ... 2.3 Steam System......the generation, handling, storage and transportation of ...

  11. Microsoft Word - N0075800-NAPL April to June 04.doc

    Office of Legacy Management (LM)

    ... water pollution prevention plan was finalized by the subcontractor by the end of June. The application for the modification of the existing synthetic non-Title V Air Emissions ...

  12. M&V 2.0 Demonstrations

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Long-term: scaled adoption of cost effective, accurate, meter-based savings estimation Below: Replication of CBI Logic Model - objectives, activities, short- mid- and long-term ...

  13. M&V Guidelines: Measurement and Verification for Federal Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    nEnergyPlus%2Bredirect%2B1 for discussion of simulation issues. 17 http:rredc.nrel.govsolarolddatansrdb1991-2005tmy3. 18 See ASHRAE Guideline 14-2015 and Section 4.2.2...

  14. M&V Guidelines: Measurement and Verification for Federal Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... measured (e.g., reduced solar gain and heat loss through ... The power draw on lighting, plug load, HVAC equipment, and ... controls, exterior photocells, and improved programmed ...

  15. M&V Guidelines: Measurement and Verification for Federal Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    staff. The persistence of the changes can be addressed through checking performance benchmarks, conducting periodic tune-ups, or a more aggressive commissioning approach. This...

  16. MHK ISDB/Instruments/POS MV Surfmaster | Open Energy Information

    Open Energy Info (EERE)

    Velocity Planar Measurement (Current), 3D Velocity Volumetric Measurement (Current), Density (Ice), Direction (Ice), Speed (Ice), Thickness (Ice), Pressure (Tidal), Sea Surface...

  17. Microsoft Word - DOE_RM_DM-#102768-v1-NAPL_Quarterly_Report_Jan...

    Office of Legacy Management (LM)

    .........2 4.0 Problems......a description of planning and construction ... Wiring for all these systems will be installed. An emergency ...

  18. Microsoft Word - DOE_RM_DM-#341474-v1-NAPL_Quarterly_April_-...

    Office of Legacy Management (LM)

    .........2 4.0 Problems......a description of planning and construction ... pumps, steam generator, emergency generator, and various ...

  19. Six novel transition-metal phosphite compounds, with structure related to yavapaiite: Crystal structures and magnetic and thermal properties of A{sup I}[M{sup III}(HPO{sub 3}){sub 2}] (A=K, NH{sub 4}, Rb and M=V, Fe)

    SciTech Connect (OSTI)

    Hamchaoui, Farida; Alonzo, Veronique; Universite Europeenne de Bretagne ; Venegas-Yazigi, Diego; Rebbah, Houria; Le Fur, Eric

    2013-02-15

    Six new transition metal(III) phosphites A{sup I}[V{sup III}(HPO{sub 3}){sub 2}], where A=K (1), NH{sub 4} (2) and Rb (3) and A{sup I}[Fe{sup III}(HPO{sub 3}){sub 2}] where A=K (4), NH{sub 4} (5) and Rb (6) have been synthesized under hydrothermal conditions and the solid-state structures were solved from single-crystal X-ray diffraction data. These compounds crystallize in the hexagonal system, space group P6{sub 3}mc (no. 186), with a=5.3294(2) A and c=12.3130(5) A for 1, a=5.3330(2) A and c=12.8760(4) A for 2, a=5.3459(2) A and c=12.6850(8) A for 3, a=5.3256(1) A and c=12.2362(3) A for 4, a=5.3229(2) A and c=12.8562(4) A for 5, a=5.3393(2) A and c=12.6913(5) A for 6, with Z=2 in the six phases. The crystal structures of these compounds are isotypic and exhibit a layered structure stacked along the c-axis with the A{sup +} cations located in the interlayer space. The [M{sup III}(HPO{sub 3}){sub 2}]{sup -} sheets are formed by MO{sub 6} octahedra interconnected by HPO{sub 3} tetrahedral phosphite oxoanions through sharing vertices. Thermal analysis shows a large range of stability for compounds containing potassium and rubidium cations with decomposition starting around 550 K for stable compounds and above 840 K for the most stable compounds leading in general to pyrophosphate compounds. Triangular nets of metallic centers are observed within the layers in which antiferromagnetic interactions are evidenced by magnetic susceptibility measurements suggesting magnetic frustration. - Graphical abstract: Six new transition metal(III) phosphites A{sup I}[M{sup III}(HPO{sub 3}){sub 2}], where A=K, NH{sub 4}, Rb and M=V, Fe, have been synthesized. The crystal structures of these compounds are isotypic and exhibit a lamellar structure related to Yavapaiite. The M(HPO{sub 3}){sub 2} layers separated by cationic species present the metallic centers in a triangular arrangement. Bulk antiferromagnetic behavior is observed for all the studied compounds. Highlights: Black

  20. Microsoft Word - DOE_RM_DM-#344133-v1-Final_NAPL_Quarterly_July-Sept_2005.Dƒ

    Office of Legacy Management (LM)

    1 2005 - -L U.S. Department of Energy Work Performed Under DOE Contract No. for the U.S. Department of Energy Office of Legacy Management. DE-AC01-02GJ79491 Approved for public release; distribution is unlimited. Office of Legacy Management Office of Legacy Management Office of Legacy Management Pinellas Environmental Restoration Project Northeast Site Non-Aqueous Phase Liquids Interim Measure Progress Report July Through September 2005 October 2005 DOE-LM/GJ1011-2005 Pinellas Environmental

  1. Deadline to Review Draft M&V Guidelines Extended to December...

    Broader source: Energy.gov (indexed) [DOE]

    Federal Energy Management Program (FEMP) is extending its request for public comment on ... FEMP has reopened the comment period and requests that new comments on this draft be sent ...

  2. Buffalo County, Wisconsin: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Wisconsin Modena, Wisconsin Mondovi, Wisconsin Montana, Wisconsin Naples, Wisconsin Nelson, Wisconsin Waumandee, Wisconsin Retrieved from "http:en.openei.orgw...

  3. Niagara Air Quality Survey Report, 1987: Occidental Chemical Corporation, Niagara Falls, New York, USA, non-aqueous phase liquid (NAPL) incineration test. Report no. ARB-166-87-AR/SP

    SciTech Connect (OSTI)

    Bell, R.W.; DeBrou, G.

    1988-01-01

    An ambient air quality survey was conducted in the Niagara Falls area of Ontario from October 8-12, 1987 to provide on-site real-time screening for selected polychlorinated biphenyl congeners and other chlorinated organics at times when the Occidental Chemical Corporation was conducting tests at its liquid hazardous waste incineration facility in Niagara Falls, N.Y. During the incineration tests, the winds were such that the gaseous emissions from the Occidental facility were carried into the U.S. Since the monitoring units were restricted to the Canadian side of the Niagara River, only upwind air quality parameters could be measured.

  4. Calculations of atomic sputtering and displacement cross-sections in solid elements by electrons with energies from threshold to 1. 5 MV

    SciTech Connect (OSTI)

    Bradley, C.R.

    1988-12-01

    The kinetics of knock-on collisions of relativistic electrons with nuclei and details of the numerical evaluation of differential, recoil, and total Mott cross-sections are reviewed and discussed. The effects of electron beam induced displacement and sputtering, in the transmission electron microscope (TEM) environment, on microanalysis are analyzed with particular emphasis placed on the removal of material by knock-on sputtering. The mass loss predicted due to transmission knock-on sputtering is significant for many elements under conditions frequently encountered in microanalysis. Total Mott cross-sections are tabulated for all naturally occurring solid elements up to Z = 92 at displacement energies of one, two, four, and five times the sublimation energy and for accelerating voltages accessible in the transmission electron microscope. Fortran source code listings for the calculation of the differential Mott cross-section as a function of electron scattering angle (dMottCS), as a function of nuclear recoil angle (RECOIL), and the total Mott cross-section (TOTCS) are included. 48 refs., 21 figs., 12 tabs.

  5. WE-G-17A-09: Novel Magnetic Shielding Design for Inline and Perpendicular Integrated 6 MV Linac and 1.0 T MRI Systems

    SciTech Connect (OSTI)

    Li, X; Ma, B; Kuang, Y; Diao, X

    2014-06-15

    Purpose: The influence of fringe magnetic fields delivered by magnetic resonance imaging (MRI) on the beam generation and transportation in Linac is still a major challenge for the integration of linear accelerator and MRI (Linac-MRI). In this study, we investigated an optimal magnetic shielding design for Linac-MRI and further characterized the beam trajectory in electron gun. Methods: Both inline and perpendicular configurations were analyzed in this study. The configurations, comprising a Linac-MRI with a 100cm SAD and an open 1.0 T superconductive magnet, were simulated by the 3D finite element method (FEM). The steel shielding around the Linac was included in the 3D model, the thickness of which was varied from 1mm to 20mm, and magnetic field maps were acquired with and without additional shielding. The treatment beam trajectory in electron gun was evaluated using OPERA 3d SCALA with and without shielding cases. Results: When Linac was not shielded, the uniformity of diameter sphere volume (DSV) (30cm) was about 5 parts per million (ppm) and the fringe magnetic fields in electron gun were more than 0.3 T. With shielding, the magnetic fields in electron gun were reduced to less than 0.01 T. For the inline configuration, the radial magnetic fields in the Linac were about 0.02T. A cylinder steel shield used (5mm thick) altered the uniformity of DSV to 1000 ppm. For the perpendicular configuration, the Linac transverse magnetic fields were more than 0.3T, which altered the beam trajectory significantly. A 8mm-thick cylinder steel shield surrounding the Linac was used to compensate the output losses of Linac, which shifted the magnetic fields' uniformity of DSV to 400 ppm. Conclusion: For both configurations, the Linac shielding was used to ensure normal operation of the Linac. The effect of magnetic fields on the uniformity of DSV could be modulated by the shimming technique of the MRI magnet. NIH/NIGMS grant U54 GM104944, Lincy Endowed Assistant Professorship.

  6. Property Transfer Review

    Office of Environmental Management (EM)

    Department of Energy Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation Paper presented at the Third International Conference on Oxidation and Reduction Technologies for Soil and Groundwater. October 2004, San Diego, California. Michael Butherus, David S. Ingle, Randall Juhlin, Joseph Daniel Project Overview: Successful Field-Scale In Situ Thermal NAPL Remediation (305.82 KB) More Documents &

  7. U.S. DEPARTMENT OF ENERGY * SAVANNAH RIVER SITE * AIKEN * SC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    NAPL Calculator: (Non-aqueous Phase Liquid) An environmental engineer at the Savannah River Site has developed a software application that will determine if non-aqueous phase liquid (NAPL) contaminants are present in soil, groundwater, or soil vapor samples. The software will determine both the quantity and composition of NAPL chemicals in the samples based on the results of sample analysis. The software also computes important environmental engineering measures such as the residual saturation,

  8. Scott County, Illinois: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Zone Subtype A. Places in Scott County, Illinois Alsey, Illinois Bluffs, Illinois Exeter, Illinois Glasgow, Illinois Manchester, Illinois Naples, Illinois Winchester, Illinois...

  9. EIS-0409: Mitigation Action Plan | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Draft Environmental Impact Statement EIS-0409: Final Environmental Impact Statement Successful Field-Scale In Situ Thermal NAPL Remediation at the Young - Rainey STAR Center...

  10. Remediation

    SciTech Connect (OSTI)

    Oostrom, Mart; Falta, Ron W.; Mayer, Alex S.; Javandel, I.; Hassanizadeh, S. M.

    2005-12-06

    The three most frequently used remediation technologies are discussed: (1) NAPL removal, (2) Pump-and-Treat, (3) Soil Vapor Extraction.

  11. Clark County, South Dakota: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Climate Zone Number 6 Climate Zone Subtype A. Places in Clark County, South Dakota Bradley, South Dakota Clark, South Dakota Garden City, South Dakota Naples, South Dakota...

  12. Cumberland County, Maine: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Maine Freeport, Maine Frye Island, Maine Gorham, Maine Gray, Maine Harpswell, Maine Harrison, Maine Little Falls-South Windham, Maine Long Island, Maine Naples, Maine New...

  13. Ontario County, New York: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    New York Naples, New York Phelps, New York Richmond, New York Rushville, New York Seneca, New York Shortsville, New York South Bristol, New York Victor, New York West...

  14. Non-Aqueous Phase Liquid Calculator

    Energy Science and Technology Software Center (OSTI)

    2004-02-19

    Non-Aqueous Phase Liquid or "NPAL" is a term that most environmental professionals are familiar with because NAPL has been recognized in the literature as a significant source of groundwater contamination. There are two types of NAPL: DNAPL and LNAPL. DNAPL is a ‘dense’ non-aqueous phase liquid. In this context, dense means having a density greater than water (1.0 kg/L). Trichloroethylene (TCE) and tetrachioroethylene (PCE) are examples of DNAPL compounds. A compound that is heaver thanmore » water means this type of NAPL will sink in an aquifer. Conversely, LNAPL is a ‘light’ non-aqueous phase liquid with a density less than water, and will float on top of the aquifer. Examples of LNAPL’s are benzene and toluene. LNAPL or DNAPL often manifest as a complex, multi-component mixture of organic compounds that can occur in environmental media. Complex multi-component mixtures distributed in soil pore-air, pore-water, soil particles and in free phase complicate residual saturation of single and multi component NAPL compounds in soil samples. The model output also includes estimates of the NAPL mass and volume and other physical and chemical properties that may be useful for characterization, modeling, and remedial system design and operation. The discovery of NAPL in the aquifer usually leads to a focused characterization for possible sources of NAPL in the vadose zone using a variety of innovative technologies and characterization methods. Often, the analytical data will indicated the presence of NAPL, yet, the NAPL will go unrecognized. Failure to recognize the NAPL can be attributed to the complicated processes of inter-media transfer or a general lack of knowledge about the physical characteristics of complex organic mixtures in environmental samples.« less

  15. Microsoft Word - S05827_WCR_Final.doc

    Office of Legacy Management (LM)

    ...L) Upper Piezometer Development MV-1 - Air MV-1 Well Dev. 052509 2250 WD 36.56 -1441 ...L) Upper Piezometer Development MV-3 - Air MV-3 Well Dev. 060309 2325 WD 37.56 -4324 ...

  16. Assessment of Advanced Measurement and Verification Methods ...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    (M&V 2.0) Assessment of Advanced Measurement and Verification Methods (M&V 2.0) Automated M&V from Noesis Automated M&V from Noesis Lead Performer: Lawrence Berkeley ...

  17. Saccharification of newspaper waste after ammonia fiber expansion...

    Office of Scientific and Technical Information (OSTI)

    ... Universitario Monte S. Angelo, Via Cintia, 4, 80126 Naples, Italy Full list of author information is available at the end of the article water by leachate, as well as air pollution ...

  18. Automotive Accessibility and Efficiency Meet in the Innovative...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Automotive Accessibility and Efficiency Meet in the Innovative MV-1 Automotive Accessibility and Efficiency Meet in the Innovative MV-1 March 11, 2011 - 4:03pm Addthis The MV-1, a ...

  19. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Joint Venture (United States) Strategic Petroleum Reserve Office, New Orleans, ... body radiotherapy underwent treatment planning for a 7 MV FFF and a 6 MV FF beams to ...

  20. Measurement and Verification for Federal Energy Savings Performance...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Measurement and verification (M&V) activities help agencies confirm that legally and ... When done correctly, M&V: Appropriately allocates risks Reduces uncertainty of savings ...

  1. State and Local Energy Savings Performance Contracting: Savings...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Savings Measurement and Verification (M&V) State and Local Energy Savings Performance Contracting: Savings Measurement and Verification (M&V) DOE's Technical Assistance Program ...

  2. Transformer current sensor for superconducting magnetic coils

    DOE Patents [OSTI]

    Shen, S.S.; Wilson, C.T.

    1985-04-16

    The present invention is a current transformer for operating currents larger than 2kA (two kiloamps) that is capable of detecting a millivolt level resistive voltage in the presence of a large inductive voltage. Specifically, the present invention includes substantially cylindrical primary turns arranged to carry a primary current and substantially cylindrical secondary turns arranged coaxially with and only partially within the primary turns, the secondary turns including an active winding and a dummy winding, the active and dummy windings being coaxial, longitudinally separated and arranged to mutually cancel voltages excited by commonly experienced magnetic fields, the active winding but not the dummy winding being arranged within the primary turns.

  3. Structure and physical properties of single crystal PrCr{sub 2}Al{sub 20} and CeM{sub 2}Al{sub 20} (M=V, Cr): A comparison of compounds adopting the CeCr{sub 2}Al{sub 20} structure type

    SciTech Connect (OSTI)

    Kangas, Michael J.; Schmitt, Devin C.; Sakai, Akito; Nakatsuji, Satoru; Institute of Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 ; Chan, Julia Y.

    2012-12-15

    Crystal growth and full structure determination of compounds adopting the CeCr{sub 2}Al{sub 20} structure type, LnTi{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), LnV{sub 2}Al{sub 20} (Ln=La-Pr, and Sm), and LnCr{sub 2}Al{sub 20} (Ln=La-Pr, Sm, and Yb), are reported. Resistivity, magnetic susceptibility, and heat capacity of flux grown single crystals of the nonmagnetic CeM{sub 2}Al{sub 20} (Ln=Ce, Yb; M=Ti, V) compounds are compared to PrCr{sub 2}Al{sub 20}. Of particular interest is PrCr{sub 2}Al{sub 20} which does not show any phase transition down to the lowest temperature of the measurement (400 mK in resistivity measurement and 1.8 K for magnetic susceptibility measurements) and exhibits Kondo behavior at low temperatures. - Graphical abstract: Crystal structure of SmV{sub 2}Al{sub 20} showing the interpenetrating diamond-like samarium network and pyrochlore-like vanadium network. Highlights: Black-Right-Pointing-Pointer Single crystals of LnM{sub 2}Al{sub 20} were grown from a molten aluminum flux. Black-Right-Pointing-Pointer Magnetic, electrical, and specific heat of single crystal LnM{sub 2}Al{sub 20} are presented. Black-Right-Pointing-Pointer PrCr{sub 2}Al{sub 20} exhibits evidence of Kondo effect.

  4. Acoustically enhanced remediation of contaminated soils and ground water. Volume 1

    SciTech Connect (OSTI)

    1995-10-01

    The Phase 1 laboratory bench-scale investigation results have shown that acoustically enhanced remediation (AER) technology can significantly accelerate the ground water remediation of non-aqueous phase liquids (NAPLs) in unconsolidated soils. The testing also determined some of the acoustic parameters which maximize fluid and contaminant extraction rates. A technology merit and trade analysis identified the conditions under which AER could be successfully deployed in the field, and an analysis of existing acoustical sources and varying methods for their deployment found that AER technology can be successfully deployed in-situ. Current estimates of deployability indicate that a NAPL plume 150 ft in diameter can be readily remediated. This program focused on unconsolidated soils because of the large number of remediation sites located in this type of hydrogeologic setting throughout the nation. It also focused on NAPLs and low permeability soil because of the inherent difficult in the remediation of NAPLs and the significant time and cost impact caused by contaminated low permeability soils. This overall program is recommended for Phase 2 which will address the technology scaling requirements for a field scale test.

  5. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... properties (1) dielectric thin films (1) diffusion (1) ... onto the film surface. Surface potential decreased from about 280mV to about 100 mV and resistance decreased ...

  6. Influence of acidic pH on hydrogen and acetate production by...

    Office of Scientific and Technical Information (OSTI)

    mV (0.065 mAcm2 sterile control at -800 mV) by the Acetobacterium-dominated community. ... Dept. of Ecology and Evolution; Marine Biological Lab., Woods Hole, MA (United States); ...

  7. Guide to Government Witnessing and Review of Measurement and...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    witnessing of measurement and verification (M&V) activities in Federal energy savings performance contract (ESPC) projects. Witnessing of M&V activities is a part of the process of ...

  8. Spectroscopy of Supercapacitor Electrodes In Operando

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    electrode in 1 M NaCl (aq) under (a) constant dc biases between +250 and +1000 mV (green), (b) zero bias (orange), and (c) -1000 mV (dark blue). Fits to the experimental...

  9. Example Measurement and Verification Plan for an ESPC Project

    Office of Energy Efficiency and Renewable Energy (EERE)

    Report features a comprehensive measurement and verification (M&V) plan for a fictitious energy savings performance contract (ESPC) project.

  10. Measurement and Verification Plan and Savings Calculations Methods Outline (IDIQ Attachment J-8)

    Broader source: Energy.gov [DOE]

    Document outlines measurement and verification (M&V) planning and savings calculation methods for an energy savings performance contract (ESPC).

  11. Guide to Government Witnessing and Review of Measurement and Verification Activities

    Broader source: Energy.gov [DOE]

    Document provides guidance pertaining to government witnessing of measurement and verification (M&V) activities in Federal energy savings performance contract (ESPC) projects. Witnessing of M&V activities is a part of the process of reviewing and approving M&V deliverables and the on-site inspections, spot measurements, short-term monitoring, and performance tests described in the M&V plan.

  12. Measurement and Verification Activities Required in the Energy Savings Performance Contract Process

    Broader source: Energy.gov [DOE]

    There are four major measurement and verification (M&V) activities in the energy savings performance contract (ESPC) procurement process.

  13. Microsoft Word - S05827_WCR_Final.doc

    Office of Legacy Management (LM)

    MV-5 Data This page intentionally left blank U.S. Department of Energy Well Completion Report for CAU 443 CNTA December 2009 Doc. No. S05827 Page C-1 Table C-1. MV-5 Chronology Date Time Depth (ft bgs) Activity 05/09/09 through 05/10/09 NA NA Move rig and equipment from MV-4 pad to MV-5 pad and prepare to drill MV-5. 05/10/09 12:10 0 Rig inspection and drill pad walk through inspection, continue with preparations for drilling. 05/10/09 14:00 0 Begin drilling 31-inch diameter conductor casing

  14. Electrogenerative oxidation of lower alcohols to useful products

    DOE Patents [OSTI]

    Meshbesher, Thomas M.

    1987-01-01

    In the disclosed electrogenerative process for converting alcohols such as ethanol to aldehydes such as acetaldehyde, the alcohol starting material is an aqueous solution containing more than the azeotropic amount of water. Good first-pass conversions (<40% and more typically <50%) are obtained at operating cell voltages in the range of about 80 to about 350 millivolts at ordinary temperatures and pressures by using very high flow rates of alcohol to the exposed anode surface (i.e. the "gas" side of an anode whose other surface is in contact with the electrolyte). High molar flow rates of vaporized aqueous alcohol also help to keep formation of undesired byproducts at a low level.

  15. HYDROGEL TRACER BEADS: THE DEVELOPMENT, MODIFICATION, AND TESTING OF AN INNOVATIVE TRACER FOR BETTER UNDERSTANDING LNAPL TRANSPORT IN KARST AQUIFERS

    SciTech Connect (OSTI)

    Amanda Laskoskie, Harry M. Edenborn, and Dorothy J. Vesper

    2012-01-01

    The goal of this specific research task is to develop proxy tracers that mimic contaminant movement to better understand and predict contaminant fate and transport in karst aquifers. Hydrogel tracer beads are transported as a separate phase than water and can used as a proxy tracer to mimic the transport of non-aqueous phase liquids (NAPL). They can be constructed with different densities, sizes & chemical attributes. This poster describes the creation and optimization of the beads and the field testing of buoyant beads, including sampling, tracer analysis, and quantitative analysis. The buoyant beads are transported ahead of the dissolved solutes, suggesting that light NAPL (LNAPL) transport in karst may occur faster than predicted from traditional tracing techniques. The hydrogel beads were successful in illustrating this enhanced transport.

  16. Surface and Interfacial Properties of Nonaqueous-Phase Liquid Mixtures Released to the Subsurface at the Hanford Site

    SciTech Connect (OSTI)

    Nellis, Scott; Yoon, Hongkyu; Werth, Charlie; Oostrom, Martinus; Valocchi, Albert J.

    2009-05-01

    Surface and interfacial tensions that arise at the interface between different phases are key parameters affecting Nonaqueous Phase Liquid (NAPL) movement and redistribution in the vadose zone after spill events. In this study, the impact of major additive components on surface and interfacial tensions for organic mixtures and wastewater was investigated. Organic mixture and wastewater compositions are based upon carbon tetrachloride (CT) mixtures released at the Hanford site, where CT was discharged simultaneously with dibutyl butyl phosphonate (DBBP), tributyl phosphate (TBP), dibutyl phosphate (DBP), and a machining lard oil (LO). A considerable amount of wastewater consisting primarily of nitrates and metal salts was also discharged. The tension values measured in this study revealed that the addition of these additive components caused a significant lowering of the interfacial tension with water or wastewater and the surface tension of the wastewater phase in equilibrium with the organic mixtures, compared to pure CT, but had minimal effect on the surface tension of the NAPL itself. These results lead to large differences in spreading coefficients for several mixtures, where the additives caused both a higher (more spreading) initial spreading coefficient and a lower (less spreading) equilibrium spreading coefficient. This indicates that if these mixtures migrate into uncontaminated areas, they will tend to spread quickly, but form a higher residual NAPL saturation after equilibrium, as compared to pure CT. Over time, CT likely volatilizes more rapidly than other components in the originally disposed mixtures and the lard oil and phosphates would become more concentrated in the remaining NAPL, resulting in a lower interfacial tension for the mixture. Spreading coefficients are expected to increase and perhaps change the equilibrated organic mixtures from nonspreading to spreading in water-wetting porous media. These results show that the behavior of organic

  17. 1B-03.doc

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    1B-03, in: A.R. Gavaskar and A.S.C. Chen (Eds.), Remediation of Chlorinated and Recalcitrant Compounds -2004. Proceedings of the Fourth International Conference on Remediation of Chlorinated and Recalcitrant Compounds (Monterey, CA; May 2004). ISBN 1-57477-145-0, published by Battelle Press, Columbus, OH, www.battelle.org/bookstore. NONAQUEOUS-PHASE LIQUID CHARACTERIZATION AND POST-REMEDIATION VERIFICATION SAMPLING ABSTRACT: Light and dense nonaqueous-phase liquids (NAPLs) were identified in the

  18. Proceedings of the international workshop on measurement and computation of turbulent nonpremixed flames

    SciTech Connect (OSTI)

    Barlow, R.S.

    1996-10-01

    This report documents the proceedings of the International Workshop on Measurement and Computation of Turbulent Nonpremixed Flames, held in Naples, Italy on July 26--27, 1996. Contents include materials that were distributed to participants at the beginning of the workshop, as well as a Summary of Workshop Accomplishments that was generated at the close to this Naples meeting. The Naples workshop involved sixty-one people from eleven countries. The primary objectives were: (1) to select a set of well-documented and relatively simple flames that would be appropriate for collaborative comparisons of model predictions; and (2) to specify common submodels to be used in these predictions, such that models for the coupling of turbulence and chemistry might be isolated and better understood. Studies involve hydrogen and natural gas fuels. These proceedings are also published on the Web and those interested in the ongoing process of data selection and model comparison should consult the workshop page for the most recent and complete information on these collaborative research efforts. The URL is: http://www/ca.sandia/gov/tdf/Workshop.html.

  19. Lead in human blood from children living in Campania, Italy

    SciTech Connect (OSTI)

    Amodio-Cocchieri, R.; Arnese, A.; Prospero, E.; Roncioni, A.

    1996-03-01

    Blood lead (PbB) levels were determined in children living Campania (in Naples and in a rural zone in the district of Caserta). Atmospheric lead (PbA) concentration in these considered areas was monitored for 1 yr (1993-1994). The children tested were questioned about common sources of lead, other than atmospheric relating to their living and dietary habits. The PbB levels in children living in Naples were at the 50th percentile, 18.8 {mu}g/dl in males and 13.7 {mu}g/dl in females; in children living in the rural area the median PbB levels were 8.9{mu}g/dl in males, and 9.9 {mu}g/dl in females. The annual mean values of atmospheres lead were 1.15 {plus_minus} 0.24 {mu}g/dl in Naples and 0.23 {plus_minus} 0.07 {mu}g/dl in the rural area. Significant and congruent mean differences between urban and rural sites were found in children`s blood and concurrent air lead. Considering the PbB level of 10 {mu}g/dl as the maximum level that is not associated any known adverse effect in children, the Neapolitan group can be considered at risk of chronic intoxication by lead. 18 refs., 3 figs., 4 tabs.

  20. Standard Measurement & Verification Plan for Lighting Equipment Retrofit or Replacement Projects

    SciTech Connect (OSTI)

    Richman, Eric E.

    2009-11-04

    This document provides a framework for a standard Measurement and Verification (M&V) plan for lighting projects. It was developed to support cost-effective retrofits (partial and complete replacements) of lighting systems and is intended to provide a foundation for an M&V plan for a lighting retrofit utilizing a "best practice" approach, and to provide guidance to site owners, contractors, and other involved organizations on what is essential for a robust M&V plan for lighting projects. This document provides examples of appropriate elements of an M&V plan, including the calculation of expected energy savings. The standard M&V plan, as provided, also allows for consistent comparison with other similar lighting projects. Although intended for lighting retrofit applications, M&V plans developed per this framework document may also be used for other non-lighting technology retrofits and new installations.

  1. Measurement and Verification of Energy Savings and Performance from Advanced Lighting Controls

    Broader source: Energy.gov [DOE]

    This document provides a framework for measurement and verification (M&V) of energy savings, performance, and user satisfaction from lighting retrofit projects involving occupancy-sensor-based, daylighting, and/or other types of automatic lighting. It was developed to provide site owners, contractors, and other involved organizations with the essential elements of a robust M&V plan for retrofit projects and to assist in developing specific project M&V plans.

  2. ARM - Datastreams - prpfrsr

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ( time ) Shortwave broadband total downwelling irradiance No-shadow record, mean signal from the broadband channel when no shadow is detected mV signalbroadband ( time )...

  3. Federal Utility Partnership Working Group (FUPWG) Spring 2011...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    are determined before the project; custom savings: the savings are not pre-determined (M&V is required) UTILITY BUSINESS PRACTICES ISSUES COMPETITIVE SUBCONTRACTING - GORDON...

  4. Well Completion Report for Corrective Action Unit 443 Central Nevada Test Area Nye County, Nevada

    SciTech Connect (OSTI)

    2009-12-01

    The drilling program described in this report is part of a new corrective action strategy for Corrective Action Unit (CAU) 443 at the Central Nevada Test Area (CNTA). The drilling program included drilling two boreholes, geophysical well logging, construction of two monitoring/validation (MV) wells with piezometers (MV-4 and MV-5), development of monitor wells and piezometers, recompletion of two existing wells (HTH-1 and UC-1-P-1S), removal of pumps from existing wells (MV-1, MV-2, and MV-3), redevelopment of piezometers associated with existing wells (MV-1, MV-2, and MV-3), and installation of submersible pumps. The new corrective action strategy includes initiating a new 5-year proof-of-concept monitoring period to validate the compliance boundary at CNTA (DOE 2007). The new 5-year proof-of-concept monitoring period begins upon completion of the new monitor wells and collection of samples for laboratory analysis. The new strategy is described in the Corrective Action Decision Document/Corrective Action Plan addendum (DOE 2008a) that the Nevada Division of Environmental Protection approved (NDEP 2008).

  5. High Impact Technology HQ - Resources for Evaluators - General...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    main phases govern demonstrations: Site Evaluation, Selection and Project Kick-Off, ... of Advanced Measurement and Verification Methods (M&V 2.0) Reviewing Measurement and ...

  6. ESPC ENABLE Measurement and Verification Protocol

    Broader source: Energy.gov [DOE]

    Document provides an overview of the Measurement and Verification (M&V) Protocol utilized within ENABLE energy savings performance contract projects.

  7. High Impact Technology Hub - Resources for Evaluators - General...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    M&V Guidelines: Measurement and Verification for Federal Energy Projects (Version 4.0) Assessment of Evaluation, Measurement, and Verification Methods - 2014 BTO Peer Review ...

  8. Standard Measurement and Verification Plan for Lighting Retrofit Projects for Buildings and Building Sites

    SciTech Connect (OSTI)

    Richman, Eric E.

    2012-10-31

    This document provides a framework for standard measurement and verification (M&V) of lighting retrofit and replacement projects. It was developed to provide site owners, contractors, and other involved organizations with the essential elements of a robust M&V plan for lighting projects. It includes details on all aspects of effectively measuring light levels of existing and post-retrofit projects, conducting power measurement, and developing cost-effectiveness analysis. This framework M&V plan also enables consistent comparison among similar lighting projects, and may be used to develop M&V plans for non--lighting-technology retrofits and new installations.

  9. Assessment of Automated Measurement and Verification Methods

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... Many buildings, metered data * Split data set into hypothetical training & prediction ... M&V models, representative data set of 100s of buildings from PG&E territory ...

  10. Quadrennial Energy Review Comments by FirstFuel Software, Inc...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Distribution (T&D) Resource Promote Meter-Based Measurement and Verification (M&V) ... Especially as "smart meter" deployments roll out across the country, utilities and ...

  11. Notice of Intent: Upcoming Funding Opportunity for Next Generation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    NGEMs combine high power density, high RPM motors with integrated power electronics. Specifically, this upcoming FOA will facilitate efforts to integrate Medium Voltage (MV) class ...

  12. Wannier90

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Wannier90 Wannier90 Description Wannier90 computes maximally-localised Wannier functions (MLWF) following the method of Marzari and Vanderbilt (MV). It can be used in conjunction...

  13. Measurement and Verification for Federal Energy Savings Performance Contracts

    Broader source: Energy.gov [DOE]

    Measurement and verification (M&V) activities help agencies confirm that legally and contractually required savings guarantees are met in federal energy savings performance contracts (ESPCs).

  14. How Energy Savings Performance Contracting Can Support State...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    levels, best practices, energy savings examples, cost-effectiveness, EM&V and DOE support. ... Savings Measurement and Verification (M&V) Developing an Evaluation Measurement and ...

  15. Measurement & Verification with Green Button Data | Department...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Measurement & Verification with Green Button Data Measurement & Verification with Green ... Measurement and verification (M&V) focuses on ensuring that the savings from energy ...

  16. The nucleocapsid protein of measles virus blocks host interferon response

    SciTech Connect (OSTI)

    Takayama, Ikuyo; Sato, Hiroki; Watanabe, Akira; Omi-Furutani, Mio; Sugai, Akihiro; Kanki, Keita; Yoneda, Misako; Kai, Chieko

    2012-03-01

    Measles virus (MV) belongs to the genus Morbillivirus of the family Paramyxoviridae. A number of paramyxoviruses inhibit host interferon (IFN) signaling pathways in host immune systems by various mechanisms. Inhibition mechanisms have been described for many paramyxoviruses. Although there are inconsistencies among previous reports concerning MV, it appears that P/V/C proteins interfere with the pathways. In this study, we confirmed the effects of MV P gene products of a wild MV strain on IFN pathways and examined that of other viral proteins on it. Interestingly, we found that N protein acts as an IFN-{alpha}/{beta} and {gamma}-antagonist as strong as P gene products. We further investigated the mechanisms of MV-N inhibition, and revealed that MV-N blocks the nuclear import of activated STAT without preventing STAT and Jak activation or STAT degradation, and that the nuclear translocation of MV-N is important for the inhibition. The inhibitory effect of the N protein was observed as a common feature of other morbilliviruses. The results presented in this report suggest that N protein of MV as well as P/V/C proteins is involved in the inhibition of host IFN signaling pathways.

  17. Canine distemper virus neutralization activity is low in human serum and it is sensitive to an amino acid substitution in the hemagglutinin protein

    SciTech Connect (OSTI)

    Zhang, Xinsheng; Wallace, Olivia L.; Domi, Arban; Wright, Kevin J.; Driscoll, Jonathan; Anzala, Omu; Sanders, Eduard J.; Kamali, Anatoli; Allen, Susan; Fast, Pat; Gilmour, Jill; Price, Matt A.; Parks, Christopher L.

    2015-08-15

    Serum was analyzed from 146 healthy adult volunteers in eastern Africa to evaluate measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb) prevalence and potency. MV plaque reduction neutralization test (PRNT) results indicated that all sera were positive for MV nAbs. Furthermore, the 50% neutralizing dose (ND50) for the majority of sera corresponded to antibody titers induced by MV vaccination. CDV nAbs titers were low and generally were detected in sera with high MV nAb titers. A mutant CDV was generated that was less sensitive to neutralization by human serum. The mutant virus genome had 10 nucleotide substitutions, which coded for single amino acid substitutions in the fusion (F) and hemagglutinin (H) glycoproteins and two substitutions in the large polymerase (L) protein. The H substitution occurred in a conserved region involved in receptor interactions among morbilliviruses, implying that this region is a target for cross-reactive neutralizing antibodies. - Highlights: • Screened 146 serum samples for measles virus (MV) and canine distemper virus (CDV) neutralizing antibody (nAb). • MV nAb is prevalent in the sera. • CDV neutralizing activity is generally low or absent and when detected it is present in sera with high MV nAb titers. • A neutralization-resistant CDV mutant was isolated using human serum selection. • A mutation was identified in the receptor-binding region of CDV hemagglutinin protein that confers the neutralization resistance.

  18. Using Measurement and Verification to Manage Risk in Federal Energy- and Water-Saving Projects

    Broader source: Energy.gov [DOE]

    "Risk," in the context of measurement and verification (M&V), refers to the uncertainty that expected savings will be realized. Assumption of risk implies acceptance of the potential monetary consequences. Energy service companies (ESCOs) and agencies are each reluctant to assume responsibility for factors they cannot control, and holding certain parameters fixed in the M&V plan can match up responsibilities.

  19. Influence of Temperature on the Corrosion of Uranium Dioxide Nuclear Fuel

    SciTech Connect (OSTI)

    Broczkowski, Michael E.; Noel, Jamie J.; Shoesmith, David W.

    2007-07-01

    The anodic dissolution of UO{sub 2} has been studied at 60 deg. C and the results compared to previous observations at 22 deg. C. The rate of oxidation / dissolution was determined electrochemically at constant potentials in the range -500 mV to 500 mV (vs. SCE). The composition of the electrochemically oxidized surface was determined by X-Ray Photoelectron Spectroscopy (XPS). The onset of oxidation (UO{sub 2} {yields} UO{sub 2+x}) occurred at approximately the same potential (-400 mV) at both temperatures. However, the conversion of U{sub V} to U{sub VI}, and hence to soluble UO{sub 2}{sup 2+}, was accelerated by temperature. This acceleration of dissolution caused the development of acidity at localized sites on the fuel surface at lower (less oxidizing) potentials ({>=} 100 mV) at 60 deg. C than at 22 deg. C ({>=} 350 mV)

  20. N0057000.doc

    Office of Legacy Management (LM)

    000 GJO- 2002-380- TAC GJO-PIN 13.5.1-1 Pinellas Environmental Restoration Project Northeast Site Non-Aqueous Phase Liquids Interim Measures Progress Report July through September 2002 October 2002 Prepared by U.S. Department of Energy Grand Junction Office Grand Junction, Colorado Work Performed Under DOE Contract Number DE-AC13-02GJ79491 Task Order Number ST03-107 Document Number N0057000 Contents DOE/Grand Junction Office Northeast Site NAPL Interim Measures Progress Report October 2002 Page

  1. SREL Reprint #3230

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    0 Foraging Habitat Use by Breeding Wood Storks and the Core Foraging Area Concept A. Lawrence Bryan, Jr.1, Ken D. Meyer2, Bree A. Tomlinson3, Jason A. Lauritsen4, and William B. Brooks5 1Savannah River Ecology Laboratory, P.O. Drawer E, Aiken, SC 29802, USA 2Avian Research and Conservation Institute, Gainesville, FL, 32601, USA 3College of Charleston, Charleston, SC, 29424, USA 4National Audubon Society, Corkscrew Swamp Sanctuary, Naples, FL, 34120, USA 5U.S. Fish and Wildlife Service, North

  2. Kuwaiti oil sector shows more signs of recovery

    SciTech Connect (OSTI)

    Not Available

    1992-04-06

    This paper reports that Kuwait's oil sector continues to show signs of recovery from the Persian Gulf war. On Mar. 23 Kuwait Petroleum Co. (KPC) loaded the country's first shipment of liquefied petroleum gas for export since the Iraqi invasion in August 1990. In addition, the first shipment of Kuwaiti crude recovered from giant oil lakes formed by hundreds of wild wells sabotaged in the war was to arrive by tanker in Naples, Italy, late last month. The tanker is carrying 210,000 bbl of crude. However, the project to clean up the lakes and recover more oil, undertaken by Bechtel Corp. with Kuwait Oil Co. (KOC), has reached a stand still.

  3. Dynamic underground stripping to remediate a deep hydrocarbon spill

    SciTech Connect (OSTI)

    Yow, J.L. Jr.; Aines, R.D.; Newmark, R.L.

    1995-09-01

    Dynamic Underground Stripping is a combination of in situ steam injection, electrical resistance heating, and fluid extraction for rapid removal and recovery of subsurface contaminants such as solvents or fuels. Underground imaging and other measurement techniques monitor the system in situ for process control. Field tests at a deep gasoline spill at Lawrence Livermore National Laboratory recovered over 26,500 liters (7000 gallons) of gasoline during several months of field operations. Preliminary analysis of system cost and performance indicate that Dynamic Underground Stripping compares favorably with conventional pump-and-treat methods and vacuum extraction schemes for removing non-aqueous phase liquids (NAPLs) such as gasoline from deep subsurface plumes.

  4. Appearance of thermochemical emf in some conducting materials

    SciTech Connect (OSTI)

    Petrov, Y.S.; Maslikhov, V.V.; Shcheglov, V.D.

    1983-05-01

    The appearance of an emf in conductors when they are heated is described by the Seebeck and Thompson effects. If some part of the surface of a conductor is covered by a pyrotechnical material and ignited, then while the pyrotechnical material is burning and after it has burned, an emf arises at the ends of the conductor. The direction of the emf depends on the location of maximum temperature of the heated section of the conductor. If the heating is terminated for some time and started up again, then the emf and current appear again, with no necessity for re-application of the pyrotechnical material. Conductors of Nichrome, Constantan and tungsten, as well as graphite rods were studied with small sections of the conductors covered with lead azide, black gunpowder, or match-head composition. The current ranged from -5 to 6 microamps, and the emf from -0.4 to 1 millivolt. The effects described can be used to convert thermal energy into electrical energy in sensors, etc.

  5. Development of thermoelectric fibers for miniature thermoelectric devices

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ren, Fei; Menchhofer, Paul A.; Kiggans, Jr., James O.; Wang, Hsin

    2016-09-23

    Miniature thermoelectric (TE) devices may be used in a variety of applications such as power sources of small sensors, temperature regulation of precision electronics, etc. Reducing the size of TE elements may also enable design of novel devices with unique form factor and higher device efficiency. Current industrial practice of fabricating TE devices usually involves mechanical removal processes that not only lead to material loss but also limit the geometry of the TE elements. In this project, we explored a powder-processing method for the fabrication of TE fibers with large length-to-area ratio, which could be potentially used for miniature TEmore » devices. Powders were milled from Bi2Te3-based bulk materials and then mixed with a thermoplastic resin dissolved in an organic solvent. Through an extrusion process, flexible, continuous fibers with sub-millimeter diameters were formed. The polymer phase was then removed by sintering. Sintered fibers exhibited similar Seebeck coefficients to the bulk materials. Moreover, their electrical resistivity was much higher, which might be related to the residual porosity and grain boundary contamination. Prototype miniature uni-couples fabricated from these fibers showed a linear I-V behavior and could generate millivolt voltages and output power in the nano-watt range. Further development of these TE fibers requires improvement in their electrical conductivities, which needs a better understanding of the causes that lead to the low conductivity in the sintered fibers.« less

  6. Novel air electrode for metal-air battery with new carbon material and method of making same

    DOE Patents [OSTI]

    Ross, Jr., Philip N.

    1990-01-01

    A novel carbonaceous electrode support material is disclosed characterized by a corrosion rate of 0.03 wt. %/hour or less when measured a5 550 millivolts vs. a Hg/HgO electrode in a 30 wt. % KOH electrolyte a5 30.degree. C. The electrode support material comprises a preselected carbon black material which has been heat-treated by heating the material to a temperature of from about 2500.degree. to about 3000.degree. C. over a period of from about 1 to about 5 hours in an inert atmosphere and then maintaining the preselected carbon black material at this temperature for a period of at least about 1 hour, and preferably about 2 hours, in the inert atmosphere. A carbonaceous electrode suitable for use as an air electrode in a metal-air cell may be made from the electrode support material by shaping and forming it into a catalyst support and then impregnating it with a catalytically active material capable of catalyzing the reaction with oxygen at the air electrode of metal-air cell.

  7. Measurement&verification reality check: A yawning gapbetween theory and practice

    SciTech Connect (OSTI)

    Kumar, Satish; Haberl, Jeff; Claridge, David; Turner, Dan; O'Neal, Dennis; Sharp, Terry; Sifuentes, Teresa; Lopez, Felix; Taylor, Dub

    2002-06-01

    The success of an energy efficiency program should bemeasured in terms of the actual energy savings, and not against"stipulated" or estimated energy savings.Although M&V guidelines andprotocols have standardized methods for verifying energy savings accruingfrom the implementation of an energy efficiency project, M&V islargely viewed as a cost center rather than a value proposition. The jurymay still be out on the real value of M&V because it is oftenperceived as very expensive and too technical. This paper will reviewmeasured energy savings data from the Texas LoanSTAR Program and analyzeavailable data and program requirements of Federal and state performancecontracting programs that require some level of M&V to verify energysavings. The intent is to determine the role of M&V in differentprograms and what implications it has on the success or failure of theprograms. The paper concludes with suggestions to use M&V as a riskmanagement tool wherein both the service provider and the customer have avested interest to perform appropriate level of M&V to reduceuncertainty in energy savings in a cost effective manner.

  8. TH-E-17A-10: Markerless Lung Tumor Tracking Based On Beams Eye View EPID Images

    SciTech Connect (OSTI)

    Chiu, T; Kearney, V; Liu, H; Jiang, L; Foster, R; Mao, W; Rozario, T; Bereg, S; Klash, S

    2014-06-15

    Purpose: Dynamic tumor tracking or motion compensation techniques have proposed to modify beam delivery following lung tumor motion on the flight. Conventional treatment plan QA could be performed in advance since every delivery may be different. Markerless lung tumor tracking using beams eye view EPID images provides a best treatment evaluation mechanism. The purpose of this study is to improve the accuracy of the online markerless lung tumor motion tracking method. Methods: The lung tumor could be located on every frame of MV images during radiation therapy treatment by comparing with corresponding digitally reconstructed radiograph (DRR). A kV-MV CT corresponding curve is applied on planning kV CT to generate MV CT images for patients in order to enhance the similarity between DRRs and MV treatment images. This kV-MV CT corresponding curve was obtained by scanning a same CT electron density phantom by a kV CT scanner and MV scanner (Tomotherapy) or MV CBCT. Two sets of MV DRRs were then generated for tumor and anatomy without tumor as the references to tracking the tumor on beams eye view EPID images. Results: Phantom studies were performed on a Varian TrueBeam linac. MV treatment images were acquired continuously during each treatment beam delivery at 12 gantry angles by iTools. Markerless tumor tracking was applied with DRRs generated from simulated MVCT. Tumors were tracked on every frame of images and compared with expected positions based on programed phantom motion. It was found that the average tracking error were 2.3 mm. Conclusion: This algorithm is capable of detecting lung tumors at complicated environment without implanting markers. It should be noted that the CT data has a slice thickness of 3 mm. This shows the statistical accuracy is better than the spatial accuracy. This project has been supported by a Varian Research Grant.

  9. Imaging dose in breast radiotherapy: does breast size affect the dose to the organs at risk and the risk of secondary cancer to the contralateral breast?

    SciTech Connect (OSTI)

    Batumalai, Vikneswary; Quinn, Alexandra; Jameson, Michael; Delaney, Geoff; Holloway, Lois

    2015-03-15

    Correct target positioning is crucial for accurate dose delivery in breast radiotherapy resulting in utilisation of daily imaging. However, the radiation dose from daily imaging is associated with increased probability of secondary induced cancer. The aim of this study was to quantify doses associated with three imaging modalities and investigate the correlation of dose and varying breast size in breast radiotherapy. Planning computed tomography (CT) data sets of 30 breast cancer patients were utilised to simulate the dose received by various organs from a megavoltage computed tomography (MV-CT), megavoltage electronic portal image (MV-EPI) and megavoltage cone-beam computed tomography (MV-CBCT). The mean dose to organs adjacent to the target volume (contralateral breast, lungs, spinal cord and heart) were analysed. Pearson correlation analysis was performed to determine the relationship between imaging dose and primary breast volume and the lifetime attributable risk (LAR) of induced secondary cancer was calculated for the contralateral breast. The highest contralateral breast mean dose was from the MV-CBCT (1.79 Gy), followed by MV-EPI (0.22 Gy) and MV-CT (0.11 Gy). A similar trend was found for all organs at risk (OAR) analysed. The primary breast volume inversely correlated with the contralateral breast dose for all three imaging modalities. As the primary breast volume increases, the likelihood of a patient developing a radiation-induced secondary cancer to the contralateral breast decreases. MV-CBCT showed a stronger relationship between breast size and LAR of developing a radiation-induced contralateral breast cancer in comparison with the MV-CT and MV-EPI. For breast patients, imaging dose to OAR depends on imaging modality and treated breast size. When considering the use of imaging during breast radiotherapy, the patient's breast size and contralateral breast dose should be taken into account.

  10. March 2010 Groundwater Sampling at the Project Shoal Site, Nevada (Data Validation Package)

    SciTech Connect (OSTI)

    2011-03-01

    The U.S. Department of Energy Office of Legacy Management conducted annual sampling at the Project Shoal Area (Shoal) in March 2010. Wells HC-4, HC-5, HC-7, HC-8, MV-1, MV-2 and MV-3 were sampled March 10-12, 2010, as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PLN/S04351, continually updated). Wells HC-1, HC-2, HC-3, and HC-6 were sampled March 24, 2010, by Desert Research Institute personnel.

  11. The CAMS Accelerator Facility

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the cams accelerator facility The CAMS Accelerator Facility Today CAMS's primary facility is a ~10,000 ft2 building that houses three state-of-the-art, accelerator-based technologies. Upper Left: The HVEC 10 MV Model FN Tandem Van de Graaff Accelerator and the lighter-ion AMS beamline. Upper Right: The NEC 1.0 MV Model 3SDH-1 Tandem Accelerator for BioAMS. Lower: The NEC 1.7 MV Model 5SDH-2 Tandem Accelerator for Ion Beam Analysis and neutron production. CAMS' principal research instrument is a

  12. Smart Power Infrastructure Demonstration for Energy Reliability...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    NPS Phase 1 Thesis 19,600year 23,400year Up to 50,000day* Attributes Conservation Effect Smart Building Diagnostics M&V for EE Programs EV Integration Voltage Regulation...

  13. SIC ENABLED HIGH-FREQUENCY MEDIUM VOLTAGE DRIVE FOR HIGH-SPEED...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    A medium voltage drive system using SiC semiconductors and a high-speed motor to reduce ... MV high frequency drive, (ii) a high-speed motor, and (iii) advanced insulation systems. ...

  14. EMGeo Case Study

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    methods (QMR in one case, and IDR in the other), both solvers are dominated by memory bandwidth intensive operations like sparse matrix-vector multiply (SpMV), dot...

  15. DOE EPCA Commercial Refrigeration Standards - EERE-2010-BT-STD...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    We have a revolutionary product that is the only in the business that has built in Measurement & Verification (M&V). All other anti-sweat heater controls are old technology that ...

  16. FEMP Focus - Spring 2004

    SciTech Connect (OSTI)

    2004-04-29

    Features information about Measurement and Verification (M&V) of Energy Savings, Energy Rate Escalation calculator, Landfill Gas-to-Energy Project, Natural Gas Markets, GSA develops new O&M contract, and more for federal agencies.

  17. CEBAF SRF Performance during Initial 12 GeV Commissioning

    SciTech Connect (OSTI)

    Bachimanchi, Ramakrishna; Allison, Trent; Daly, Edward; Drury, Michael; Hovater, J; Lahti, George; Mounts, Clyde; Nelson, Richard; Plawski, Tomasz

    2015-09-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of eleven new 100 MV cryomodules (88 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. Not all the cavities were operated at the minimum gradient of 19.3 MV/m with the beam. Though the initial 12 GeV milestones were achieved during the initial commissioning of CEBAF, there are still some issues to be addressed for long term reliable operation of these modules. This paper reports the operational experiences during the initial commissioning and the path forward to improve the performance of C100 (100 MV) modules.

  18. Better Buildings Alliance, Advanced Rooftop Unit Campaign: Rooftop Unit Measurement and Verification (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-09-01

    This document provides facility managers and building owners an introduction to measurement and verification (M&V) methods to estimate energy and cost savings of rooftop units replacement or retrofit projects to estimate paybacks or to justify future projects.

  19. Research Projects

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Francois Hemez (X-1-MV: METHODS AND VERIFICATION) Dr. Gyuhae Park (INST-OFF: INSTITUTES) Dr. Irene Beyerlein (T-03: FLUID DYNAMICS) Unmanned Air Vehicles (UAV's) are being used by ...

  20. BPA, in partnership with its customer utilities, conducted an...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    3. 2. 1. 2. 3. BPA can improve reliability of savings estimates by clarifying BPA M&V protocols (e.g., first-year vs typical savings and current practice baseline), improve the...

  1. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... a search of new technologies to take advantage of renewable energy such as solar and wind. ... The MV4-HO-TEMPO ARFB has an exceptionally high cell voltage, 1.25 V. Prototypes of the ...

  2. Class 8 Truck Freight Efficiency Improvement Project

    Broader source: Energy.gov (indexed) [DOE]

    ... HEV Engine controls Integration SAE Hybrid Committee Standards development for ... testing on-going HV-LV DCDC Inverter Junction Box HV-MV DCDC HV Battery eAC Comp. ...

  3. Microsoft Word - S06596_GW.doc

    Office of Legacy Management (LM)

    101001 Field Measurements Alkalinity mgL 189 182 Conductivity c mhoscm 560 560 DO c mgL 1.4 -- ORP c mV -51 -46 pH c s.u....

  4. Microsoft Word - S02459_2006Annual GW Rpt.doc

    Office of Legacy Management (LM)

    101001 Field Measurements Alkalinity mgL 189 182 Conductivity b mhoscm 560 560 DO b mgL 1.4 -- ORP b mV -51 -46 pH b s.u....

  5. Bedrock Groundwaters -- Upgradient -- 92-06a,b

    Office of Legacy Management (LM)

    101001 Field Measurements Alkalinity mgL 189 182 Conductivity c mhoscm 560 560 DO c mgL 1.4 -- ORP c mV -51 -46 pH c s.u....

  6. Microsoft Word - S03623_2007AnnRep_091007.doc

    Office of Legacy Management (LM)

    101001 Field Measurements Alkalinity mgL 189 182 Conductivity c mhoscm 560 560 DO c mgL 1.4 -- ORP c mV -51 -46 pH c s.u....

  7. SU-E-T-423: TrueBeam Small Field Dosimetry Using Commercial Plastic

    Office of Scientific and Technical Information (OSTI)

    system and to compare them to values measured with an IBA CC01 ionization chamber and a Sun Nuclear Edge detector diode for 6 MV photon beams. Methods: The Exradin W1 is a new...

  8. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    system and to compare them to values measured with an IBA CC01 ionization chamber and a Sun Nuclear Edge detector diode for MV photon beams Methods The Exradin W1 is a new small...

  9. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    system and to compare them to values measured with an IBA CC01 ionization chamber and a Sun Nuclear Edge detector diode for 6 MV photon beams. Methods: The Exradin W1 is a new...

  10. Competing charge, spin, and superconducting orders in underdoped...

    Office of Scientific and Technical Information (OSTI)

    Ruixing ; Bonn, D.A. ; Hardy, W.N. ; Gutowski, O. ; Zimmermann, M.v. ; Hayden, S.M. ; Chang, J. 1 ; Denmark) 2 ; UBC) 2 ; DESY) 2 ; Ecole) 2 ; CIFAR) 2 ; Bristol) 2 ...

  11. PSA_Well_Completion_Report.book

    Office of Legacy Management (LM)

    ... B.1-4 Geophysical Data Project Shoal Area MV-3 Spontaneous Potential and Gamma Ray . . . . ... The Vela Uniform Program was a joint effort conducted by the U.S. Atomic Energy Commission ...

  12. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Modeling of GeoSystems;A.N. Alshawabkeh, K.R. Reddy, M.V. Khire;American Society of Civil Engineers;1028-1035 Quantitative 3D petrography using X-ray tomography 4: Assessing ...

  13. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... contacts by P implantations into either intrinsic (undoped) or in-situ B-doped a-Si layers with implied open-circuit voltages (iVsub oc) of 725 and 720 mV, respectively. ...

  14. CX-009369: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Energy Regional Innovation Cluster (M&V Equipment) CX(s) Applied: A9, B2.2 Date: 09/17/2012 Location(s): Multiple Offices(s): National Energy Technology Laboratory

  15. Microsoft Word - HV-BPL Final Report to NETL.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ... channels that control their electrical grid. ... Line (BPL) connection operating on the in-service, 0.77 mile, 69 kV transmission line ... on MV distribution lines, making ...

  16. Maldives: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    Country Profile Name Maldives Population 393,500 GDP 1,944,000,000 Energy Consumption 0.01 Quadrillion Btu 2-letter ISO code MV 3-letter ISO code MDV Numeric ISO...

  17. B O N N E V I L L E P O W E R A D M I N I S T R A T I O N

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    measure project, this should be the date when the M&V for all measures was completed. O Optional: Project Name Name assigned to project. Data Entry Fields: Columns B through AG...

  18. Medium-Voltage Cables in Nuclear Plant Applications - State of Industry and Conditioning Monitoring

    SciTech Connect (OSTI)

    J.M. Braun

    2003-10-01

    OAK-B135 This report reviews the types of medium-voltage (MV) cables in use in nuclear power plants and the techniques that are currently available to assess the condition of MV cable systems. The project identified the types of cable systems in nuclear plants and their operating conditions and then assessed the aging and failure mechanisms of these cables and suitable diagnostic test techniques. In addition, ways to alleviate conditions that cause the most severe aging were identified.

  19. Multipacting in a grooved choke joint at SRF gun for BNL ERL prototype

    SciTech Connect (OSTI)

    Xu, W.; Ben-Zvi, I.; Belomestnykh, S.; Burrill, A.; Holmes, D.; Kayran, D.; McIntyre, G.; Sheehy, B.

    2011-03-28

    The 703 MHz superconducting gun for BNL ERL prototype was tested at JLab with and without choke-joint and cathode stalk. Without choke-joint and cathode stalk, the gradient reached was 25 MV/m with Q{sup 0} {approx} 6E9. The gun cathode insertion port is equipped with a grooved choke joint for multipacting suppression. We carried out tests with choke-joint and cathode stalk. The test results show that there are at least two barriers at about 3.5 MV/m and 5 MV/m. We considered several possibilities and finally found that fine details of the grooved shape are important for multipacting suppression. A triangular groove with round crest may cause strong multipacting in the choke-joint at 3.5 MV/m, 5 MV/m and 10 MV/m. This paper presents the primary test results of the gun and discusses the multipacting analysis in the choke-joint. It also suggests possible solutions for the gun and multipacting suppressing for a similar structure.

  20. Leaching of BTEX from Aged Crude Oil Contaminated Model Soils: Experimental and Modeling Results

    SciTech Connect (OSTI)

    Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

    2005-01-01

    It is generally assumed that soil properties such as organic matter content, porosity, and mineral surface area have a significant effect on the bioavailability and leachability of aged petroleum hydrocarbons. In order to test this hypothesis, nine model soils or sorbents (i.e., fine and coarse quartz sand, montmorillonite and kaolinite clay, peat, 60? and 150? silica gel, a loam soil, and non-porous glass beads) were spiked with a crude oil, aged for 27 months in the laboratory, and transferred to glass columns for the performance of continuous flow leaching experiments. The column effluents were periodically sampled for 43 days and analyzed for BTEX. A one-dimensional flow model for predicting the dissolution and dispersion of individual hydrocarbons from a multi-component NAPL such as crude oil was used to fit the leaching data (i.e., the BTEX concentration versus time curves) by adjusting the equilibrium oil-leachate partitioning coefficient (Kol) for each respective hydrocarbon. The Peclet number, which is a measure of dispersion and a required modeling parameter, was measured in separate chloride tracer experiments for each soil column. Results demonstrate that soil properties did not significantly affect the leaching kinetics of BTEX from the columns. Instead, BTEX leaching curves could be successfully fitted with the one-dimensional NAPL dissolution flow model for all sorbents with the exception of montmorillonite clay. The fitting parameter Kol for each hydrocarbon was found to be similar to the Kol values that were independently measured for the same crude oil by Rixey et al. (Journal of Hazardous Materials B, 65: 137-156, 1999). In addition, the fitted Kol values were very similar for BTEX leaching from aged compared to freshly spiked loam soil. These findings indicate that leaching of BTEX in the aged soils that are contaminated with crude oil at the high concentrations commonly found in the environment (i.e., >20,000 mg/kg) was not affected by soil

  1. Superfund record of decision amendment (EPA Region 2): Hooker (102nd Street Landfill), Niagara Falls, NY, June 9, 1995

    SciTech Connect (OSTI)

    1995-08-01

    This decision document presents the selected modification to the original remedial action (PB91-921417) for the 102nd Street Landfill Site (the `Site`), located in Niagara Falls, New York. The modification to the selected remedy addresses the river sediments within the shallow embayment of the Niagara River adjacent to the Site. The major components of the modification to the selected remedy include: dredging the Niagara River sediments to the `clean line` with respect to Site-related contamination. These sediments, after dewatering, will NOT be incinerated, but will be consolidated on the landfill. Any NAPL found within these sediments will be extracted, and will be incinerated at an off-site facility.

  2. Superfund Record of Decision (EPA Region 2): Hooker-102nd Street Landfill, Niagara Falls, NY. (First remedial action), September 1990. Final report

    SciTech Connect (OSTI)

    Not Available

    1990-09-26

    The 22-acre Hooker-102nd Street site is a former industrial landfill in the city of Niagara Falls, Niagara County, New York. The site is adjacent to, and partially within the Niagara River's 100-year floodplain. These studies and the Remedial Investigation (RI) initiated in 1984, identified contamination in ground water, onsite and offsite soil, rivershore sediment, and within a storm sewer. Additionally, the presence of a leachate plume of non-aqueous phase liquids (NAPLs) was discovered emanating from the landfill area. The Record of Decision (ROD) is the final remedy which addresses all of the contaminated media. The primary contaminants of concern affecting the soil, sediment, and ground water are VOCs including benzene, TCE, and toluene; other organics including PCBs and phenols; and metals including arsenic.

  3. Spatial decision support for strategic environmental assessment of land use plans. A case study in southern Italy

    SciTech Connect (OSTI)

    Geneletti, Davide . E-mail: davide.geneletti@ing.unitn.it; Bagli, Stefano . E-mail: home@gecosistema.it; Napolitano, Paola . E-mail: home@gecosistema.it

    2007-07-15

    This paper presents and discusses the construction of a spatial decision-support tool for the Strategic Environmental Assessment (SEA) of a land use plan: the spatial coordination plan of the Province of Naples, in southern Italy. The decision-support tool organises the relevant information, spatially resolves the actions of the plan, predicts their environmental impacts, and generates overall performance maps. Its final goal is to provide a suitable technical support to a formal SEA procedure. The expected implications of the plan, such as changes in land use and traffic flows and urban expansion, were modelled and assessed against a set of environmental criteria using SWOT (Strengths, Weaknesses, Opportunities and Threats) analysis and mapping. It was found that the SWOT analysis provided a good basis for assessment and strategy formulation. The paper also intends to contribute to the topic of data and scale issues in SEA, by exemplifying the role played by spatial data and spatial analyses to support informative SEA.

  4. T2VOC user`s guide

    SciTech Connect (OSTI)

    Falta, R.W.; Pruess, K.; Finsterle, S.; Battistelli, A.

    1995-03-01

    T2VOC is a numerical simulator for three-phase, three-component, non-isothermal flow of water, air, and a volatile organic compound (VOC) in multidimensional heterogeneous porous media. Developed at the Lawrence Berkeley Laboratory, T2VOC is an extension of the TOUGH2 general-purpose simulation program. This report is a self-contained guide to application of T2VOC to subsurface contamination problems involving nonaqueous phase liquids (NAPLs). It gives a technical description of the T2VOC code, including a discussion of the physical processes modeled, and the mathematical and numerical methods used. Detailed instructions for preparing input data are presented along with several illustrative sample problems.

  5. sup 40 Ar- sup 39 Ar and K-Ar dating of K-rich rocks from the Roccamonfina volcano, Roman Comagmatic Region, Italy

    SciTech Connect (OSTI)

    Di Brozolo, F.R.; Di Girolamo, P.; Turi, B.; Oddone, M. )

    1988-06-01

    Roccamonfina is the northernmost Volcano of the Campanian area of the K-rich Roman comagmatic Region of Italy. It erupted a huge amount of pyroclastics and lavas belonging to both the Leucite-Basanite and Leucitite Series (LBLS) and the Shoshonite Series (SS), spread over an area of about 300 km{sup 2}. The above series correspond to the High-K Series (HKS) and Low-K Series (LKS) of Appleton (1971), respectively. {sup 40}Ar-{sup 39}Ar and K-Ar dating of samples from both series gave ages ranging from 0.656 to 0.096 Ma for the SS and from 1.03( ) to 0.053 Ma for the LBLS. These results indicate that the products of the two series were outpoured together at least between 0.7 and 0.1 Ma age, i.e. during both the so-called pre-caldera phase and the post-caldera phase of activity. The latest products of the volcanism at Roccamonfina were erupted just before the deposition of the Grey Campanian Ignimbrite, which erupted from vents located about 50 km to the south in the Phlegrean Fields near Naples and has an age of about 33,000 years. Taking into account all the available all the available radiometric data the authors conclude that Roccamonfina was active between 1.5 and 0.05 Ma ago, in excellent agreement with the stratigraphic evidence. In this same time span is concentrated the activity of all the centers of the Roman Region north of Naples.

  6. Biotic and Abiotic Transformation of a Volatile Organics Plume in a Semi-Arid Vadose Zone

    SciTech Connect (OSTI)

    Studer, J.E.; Singletary, M.A.; Miller, D.R.

    1999-04-08

    An evaluation of biotic and abiotic attenuation processes potentially important to chlorinated and non-chlorinated volatile organic compound (VOC) fate and transport in the 148 meter thick vadose zone beneath the Chemical Waste Landfill (CWL) was conducted. A unique feature of this evaluation is the comparison of two estimates of VOC mass present in the soil gas, pore-water, and solid phases (but not including mass as non-aqueous phase liquid [NAPL]) of the vadose zone in 1993. One estimate, 1,800 kg, was obtained from vadose zone transport modeling that incorporated molecular diffusion and volatilization to the atmosphere, but not biotic or chemical processes. The other estimate, 2,120 kg, was obtained from the sum of VOC mass physically removed during soil vapor extraction and an estimate of VOC mass remaining in the vadose zone in 1998, both adjusted to exclude NAPL mass. This comparison indicates that biogeochemical processes were at best slightly important to historical VOC plume development. Some evidence of aerobic degradation of non-chlorinated VOCs and abiotic transformation of 1,1,1-Trichloroethane was identified. Despite potentially amenable site conditions, no evidence was found of cometabolic and anaerobic transformation pathways. Relying principally on soil-gas analytical results, an upper-bound estimate of 21% mass reduction due to natural biogeochemical processes was developed. Although available information for the CWL indicates that natural attenuation processes other than volatilization to the atmosphere did not effective y enhance groundwater protection, these processes could be important in significantly reducing groundwater contamination and exposure risks at other sites. More laboratory and field research is required to improve our collective ability to characterize and exploit natural VOC attenuation processes, especially with respect to the combination of relatively thick and dry vadose zones and chlorinated VOCs.

  7. Beam generation and planar imaging at energies below 2.40 MeV with carbon and aluminum linear accelerator targets

    SciTech Connect (OSTI)

    Parsons, David; Robar, James L.

    2012-07-15

    Purpose: Recent work has demonstrated improvement of image quality with low-Z linear accelerator targets and energies as low as 3.5 MV. In this paper, the authors lower the incident electron beam energy between 1.90 and 2.35 MeV and assess the improvement of megavoltage planar image quality with the use of carbon and aluminum linear accelerator targets. Methods: The bending magnet shunt current was adjusted in a Varian linear accelerator to allow selection of mean electron energy between 1.90 and 2.35 MeV. Linac set points were altered to increase beam current to allow experimental imaging in a practical time frame. Electron energy was determined through comparison of measured and Monte Carlo modeled depth dose curves. Planar image CNR and spatial resolution measurements were performed to quantify the improvement of image quality. Magnitudes of improvement are explained with reference to Monte Carlo generated energy spectra. Results: After modifications to the linac, beam current was increased by a factor greater than four and incident electron energy was determined to have an adjustable range from 1.90 MeV to 2.35 MeV. CNR of cortical bone was increased by a factor ranging from 6.2 to 7.4 and 3.7 to 4.3 for thin and thick phantoms, respectively, compared to a 6 MV therapeutic beam for both aluminum and carbon targets. Spatial resolution was degraded slightly, with a relative change of 3% and 10% at 0.20 lp/mm and 0.40 lp/mm, respectively, when reducing energy from 2.35 to 1.90 MV. The percentage of diagnostic x-rays for the beams examined here, ranges from 46% to 54%.Conclusion: It is possible to produce a large fraction of diagnostic energy x-rays by lowering the beam energy below 2.35 MV. By lowering the beam energy to 1.90 MV or 2.35 MV, CNR improves by factors ranging from 3.7 to 7.4 compared to a 6 MV therapy beam, with only a slight degradation of spatial resolution when lowering the energy from 2.35 MV to 1.90 MV.

  8. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.; Battista, John R.

    2014-10-15

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen production by biocathodes poised at -600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ~5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ~6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at -765 mV (0.065 mA/cm2 sterile control at -800 mV) by the Acetobacterium-dominatedmore » community. Supplying -800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured).« less

  9. The Effect of the iBEAM Evo Carbon Fiber Tabletop on Skin Sparing

    SciTech Connect (OSTI)

    Simpson, John B. Godwin, Guy A.

    2011-10-01

    Replicating the attenuation properties of the treatment tabletop are of primary importance for accurate treatment planning; however, the effect of the tabletop on the skin-sparing properties of x-rays can be overlooked. Under some conditions, the reaction of skin to the radiation can be so serious as to be the dose-limiting organ for radiotherapy treatment. Hence, an understanding of the magnitude of the reduction in skin sparing is important. Because of the development of image-guided radiotherapy, modern tabletops have been developed without the use of metal supports that otherwise provided the necessary level of rigidity. Rigidity is instead provided by compressed foam within a carbon-fiber shell, which, although it provides artefact-free imaging and high levels of rigidity, has an adverse affect on the dose in the build-up region. Representative of this type is the iBEAM evo tabletop, whose effect on the skin dose was determined at 6-MV, 10-MV, and 18-MV x-rays. Skin dose was found to increase by 60-70% owing to the tabletop, with the effect increasing with field size and decreasing with energy. By considering an endpoint of erythema, a radiobiological advantage of selecting 10 MV over 6 MV for applicable treatments was demonstrated.

  10. Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Li, Y. M.; Liu, Kexin; Geng, Rongli

    2014-02-01

    Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6-1.6 MV/m, 21-34 MV/m, 32-35 MV/m, and > 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6-13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MP's predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.

  11. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome

    SciTech Connect (OSTI)

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.; Battista, John R.

    2014-10-15

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen production by biocathodes poised at -600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ~5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ~6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at -765 mV (0.065 mA/cm2 sterile control at -800 mV) by the Acetobacterium-dominated community. Supplying -800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured).

  12. CEBAF Upgrade: Cryomodule Performance And Lessons Learned

    SciTech Connect (OSTI)

    Drury, Michael A.; Davis, G. Kirk; Hogan, John P.; Hovater, J. Curt; King, Lawrence; Marhauser, Frank; Park, HyeKyoung; Preble, Joe; Reece, Charles E.; Rimmer, Robert A.; Wang, Haipeng; Wiseman, Mark A.

    2014-02-01

    The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the 12 GeV Upgrade is a doubling of the available beam energy of the Continuous Electron Beam Accelerator Facility (CEBAF) from 6 GeV to 12 GeV. This increase in beam energy will be due in large part to the addition of ten C100 cryomodules plus associated new RF in the CEBAF linacs. The C100 cryomodules are designed to deliver 100 MeV per installed cryomodule. Each C100 cryomodule is built around a string of eight seven-cell, electro-polished, superconducting RF cavities. While an average performance of 100MV per cryomodule is needed to achieve the overall 12 GeV beam energy goal, the actual performance goal for the cryomodules is an average energy gain of 108 MV to provide operational headroom. Cryomodule production started in December 2010. All ten of the C100 cryomodules are installed in the linac tunnels and are on schedule to complete commissioning by September 2013. Performance during Commissioning has ranged from 104 MV to 118 MV. In May, 2012 a test of an early C100 achieved 108 MV with full beam loading. This paper will discuss the performance of the C100 cryomodules along with operational challenges and lessons learned for future designs.

  13. Current transport mechanisms in plasma-enhanced atomic layer deposited AlN thin films

    SciTech Connect (OSTI)

    Altuntas, Halit E-mail: biyikli@unam.bilkent.edu.tr; Ozgit-Akgun, Cagla; Donmez, Inci; Biyikli, Necmi E-mail: biyikli@unam.bilkent.edu.tr

    2015-04-21

    Here, we report on the current transport mechanisms in AlN thin films deposited at a low temperature (i.e., 200?C) on p-type Si substrates by plasma-enhanced atomic layer deposition. Structural characterization of the deposited AlN was carried out using grazing-incidence X-ray diffraction, revealing polycrystalline films with a wurtzite (hexagonal) structure. Al/AlN/ p-Si metal-insulator-semiconductor (MIS) capacitor structures were fabricated and investigated under negative bias by performing current-voltage measurements. As a function of the applied electric field, different types of current transport mechanisms were observed; i.e., ohmic conduction (15.221.5 MV/m), Schottky emission (23.639.5 MV/m), Frenkel-Poole emission (63.8211.8 MV/m), trap-assisted tunneling (226280 MV/m), and Fowler-Nordheim tunneling (290447 MV/m). Electrical properties of the insulating AlN layer and the fabricated Al/AlN/p-Si MIS capacitor structure such as dielectric constant, flat-band voltage, effective charge density, and threshold voltage were also determined from the capacitance-voltage measurements.

  14. On the determination of reference levels for quality assurance of flattening filter free photon beams in radiation therapy

    SciTech Connect (OSTI)

    Clivio, Alessandro; Belosi, Maria Francesca; Cozzi, Luca; Nicolini, Giorgia; Vanetti, Eugenio; Fogliata, Antonella; Bolard, Grgory; Fenoglietto, Pascal; Krauss, Harald

    2014-02-15

    Purpose: New definitions for some dosimetric parameters for use in quality assurance of flattening filter free (FFF) beams generated by medical linear accelerators have been suggested. The present study aims to validate these suggestions and to propose possible reference levels. Methods: The main characteristics of FFF photon beams were described in terms of: field size, penumbra, unflatness, slope, and peak-position parameters. Data were collected for 6 and 10 MV-FFF beams from three different Varian TrueBeam Linacs. Measurements were performed with a 2D-array (Starcheck system from PTW-Freiburg) and with the portal dosimetry method GLAaS utilizing the build-in portal imager of TrueBeam. Data were also compared to ion chamber measurements. A cross check validation has been performed on a FFF beam of 6 MV generated by a Varian Clinac-iX upgraded to FFF capability. Results : All the parameters suggested to characterize the FFF beams resulted easily measurable and little variation was observed among different Linacs. Referring to two reference field sizes of 10 10 and 20 20 cm{sup 2}, at SDD = 100 cm and d = dmax, from the portal dosimetry data, the following results (averaging X and Y profiles) were obtained. Field size: 9.95 0.02 and 19.98 0.03 cm for 6 MV-FFF (9.94 0.02 and 19.98 0.03 cm for 10 MV-FFF). Penumbra: 2.7 0.3 and 2.9 0.3 mm for 6 MV-FFF (3.1 0.2 and 3.3 0.3 for 10 MV-FFF). Unflatness: 1.11 0.01 and 1.25 0.01 for 6 MV-FFF (1.21 0.01 and 1.50 0.01 for 10 MV-FFF). Slope: 0.320 0.020%/mm and 0.43 0.015%/mm for 6 MV-FFF (0.657 0.023%/mm and 0.795 0.017%/mm for 10 MV-FFF). Peak Position ?0.2 0.2 and ?0.4 0.2 mm for 6 MV-FFF (?0.3 0.2 and 0.7 0.3 mm for 10 MV-FFF). Results would depend upon measurement depth. With thresholds set to at least 95% confidence level from the measured data and to account for possible variations between detectors and methods and experimental settings, a tolerance set of: 1 mm for field

  15. Modeling the Distribution of Acidity within Nuclear Fuel (UO{sub 2}) Corrosion Product Deposits and Porous Sites

    SciTech Connect (OSTI)

    Cheong, W.J.; Keech, P.G.; Wren, J.C.; Shoesmith, D.W.; Qin, Z.

    2007-07-01

    A model for acidity within pores within corrosion products on anodically-dissolving UO{sub 2} was developed using Comsol Multiphysics 3.2 to complement ongoing electrochemical measurements. It was determined that a depression of pH within pores can be maintained if: electrochemically measured dissolution currents used in the calculations are attenuated to reflect very localized pores; corrosion potentials exceed -250 mV (vs. SCE); and pore depths are >1 {mu}m for 300 mV or >100 {mu}m for -50 mV (vs. SCE). Mixed diffusional-chemical equilibria control is suggested through deviations in the shapes between pH-potential and pH-pore depth plots. (authors)

  16. A dosimetric characterization of a novel linear accelerator collimator

    SciTech Connect (OSTI)

    Thompson, C. M.; Weston, S. J. Cosgrove, V. C.; Thwaites, D. I.

    2014-03-15

    Purpose: The aim of this work is to characterize a new linear accelerator collimator which contains a single pair of sculpted diaphragms mounted orthogonally to a 160 leaf multileaf collimator (MLC). The diaphragms have “thick” regions providing full attenuation and “thin” regions where attenuation is provided by both the leaves and the diaphragm. The leaves are mounted on a dynamic leaf guide allowing rapid leaf motion and leaf travel over 350 mm. Methods: Dosimetric characterization, including assessment of leaf transmission, leaf tip transmission, penumbral width, was performed in a plotting tank. Head scatter factor was measured using a mini-phantom and the effect of leaf guide position on output was assessed using a water phantom. The tongue and groove effect was assessed using multiple exposures on radiochromic film. Leaf reproducibility was assessed from portal images of multiple abutting fields. Results: The maximum transmission through the multileaf collimator is 0.44% at 6 MV and 0.52% at 10 MV. This reduced to 0.22% and 0.27%, respectively, when the beam passes through the dynamic leaf guide in addition to the MLC. The maximum transmission through the thick part of the diaphragm is 0.32% and 0.36% at 6 and 10 MV. The combination of leaf and diaphragm transmission ranges from 0.08% to 0.010% at 6 MV and 0.10% to 0.14% depending on whether the shielding is through the thick or thin part of the diaphragm. The off-axis intertip transmission for a zero leaf gap is 2.2% at 6 and 10 MV. The leaf tip penumbra for a 100 × 100 mm field ranges from 5.4 to 4.3 mm at 6 and 10 MV across the full range of leaf motion when measured in the AB direction, which reduces to 4.0–3.4 mm at 6 MV and 4.5–3.8 mm at 10 MV when measured in the GT direction. For a 50 × 50 mm field, the diaphragm penumbra ranges from 4.3 to 3.7 mm at 6 MV and 4.5 to 4.1 mm at 10 MV in the AB direction and 3.7 to 3.2 mm at 6 MV and 4.2 to 3.7 mm when measured in the GT direction. The

  17. Performance of 3-cell Seamless Niobium cavities

    SciTech Connect (OSTI)

    Kneisel, Peter K. [JLAB; Ciovati, Gianluigi [JLBA; Jelezov, I. [DESY, Hamburg; Singer, W. [DESY, Hamburg; Singer, X. [DESY, Hamburg

    2009-11-01

    In the last several months we have surface treated and cryogenically tested three TESLA-type 3-cell cavities, which had been manufactured at DESY as seamless assemblies by hydroforming. The cavities were completed at JLab with beam tube/flange assemblies. All three cavities performed very well after they had been post-purified with titanium at 1250C for 3 hrs. The cavities, two of which consisted of an end cell and 2 center cells and one was a center cell assembly, achieved gradients of Eacc = 32 MV/m, 34 MV/m and 35 MV/m without quenches. The performance was limited by the appearance of the Q-drop in the absence of field emission. This contribution reports about the various measurements undertaken with these cavities.

  18. Solicitation and Selection of Partner Projects, Technical Team Leads, and Measurement and Validation Contractors for the American Recovery and Reinvestment Act (ARRA) Funded Commercial Building Partnerships (CBP-2)

    SciTech Connect (OSTI)

    Nesse, Ronald J.; Baechler, Michael C.; Iverson, Megan M.

    2010-09-30

    In March 2010, Pacific Northwest National Laboratory (PNNL) joined two other labs receiving ARRA funding, Lawrence Berkeley National Laboratory (LBNL) and the National Renewable National Laboratory (NREL), to began weekly conference calls with the goal of coordinating a joint lab solicitation to support the ARRA-funded CBP project. Two solicitations were identified for: 1) new CBP Partners; 2) technical contractors to provide technical assistance and measurement and verification (M&V) contractors. The M&V contractors support the work by providing model reviews and conducting monitoring studies to verify building performance. This report documents the process used by the labs for the solicitations, and describes the process and outcomes for PNNL, selection of candidate Partners, technical teams, and M&V contractors.

  19. Renewable Energy and the International Performance Measurement and Verification Protocol

    SciTech Connect (OSTI)

    Walker, A.; Thompson, A.; Mills, D.; Kats, G. H.

    1999-04-14

    The Renewables Subcommittee for the International Performance Measurement and Verification Protocol (IPMVP) is developing a section of the IPMVP treating the special issues related to performance measurement of renewable energy systems. An industry consensus framework for measuring project benefits is important in realizing the promise of renewable energy. This work represents a voluntary, consensus-building process among sponsoring organizations from 21 countries and several disciplines. Measurement and Verification (M&V) can provide a common tool for standardization to support performance-based contracting, financing, and emissions trading. M&V can ensure that savings and generation requirements in energy projects will be achieved accurately and objectively. The protocol defines procedures that are consistently applicable to similar projects, internationally accepted, and reliable. Actual M&V project results can demonstrate success and provide developers, investors, lenders, and customers with more confidence in the value of future projects.

  20. Noise suppression in reconstruction of low-Z target megavoltage cone-beam CT images

    SciTech Connect (OSTI)

    Wang Jing; Robar, James; Guan Huaiqun

    2012-08-15

    Purpose: To improve the image contrast-to-noise (CNR) ratio for low-Z target megavoltage cone-beam CT (MV CBCT) using a statistical projection noise suppression algorithm based on the penalized weighted least-squares (PWLS) criterion. Methods: Projection images of a contrast phantom, a CatPhan{sup Registered-Sign} 600 phantom and a head phantom were acquired by a Varian 2100EX LINAC with a low-Z (Al) target and low energy x-ray beam (2.5 MeV) at a low-dose level and at a high-dose level. The projections were then processed by minimizing the PWLS objective function. The weighted least square (WLS) term models the noise of measured projection and the penalty term enforces the smoothing constraints of the projection image. The variance of projection data was chosen as the weight for the PWLS objective function and it determined the contribution of each measurement. An anisotropic quadratic form penalty that incorporates the gradient information of projection image was used to preserve edges during noise reduction. Low-Z target MV CBCT images were reconstructed by the FDK algorithm after each projection was processed by the PWLS smoothing. Results: Noise in low-Z target MV CBCT images were greatly suppressed after the PWLS projection smoothing, without noticeable sacrifice of the spatial resolution. Depending on the choice of smoothing parameter, the CNR of selected regions of interest in the PWLS processed low-dose low-Z target MV CBCT image can be higher than the corresponding high-dose image.Conclusion: The CNR of low-Z target MV CBCT images was substantially improved by using PWLS projection smoothing. The PWLS projection smoothing algorithm allows the reconstruction of high contrast low-Z target MV CBCT image with a total dose of as low as 2.3 cGy.

  1. Enrichment of Microbial Electrolysis Cell Biocathodes from Sediment Microbial Fuel Cell Bioanodes

    SciTech Connect (OSTI)

    Pisciotta, JM; Zaybak, Z; Call, DF; Nam, JY; Logan, BE

    2012-07-18

    Electron-accepting (electrotrophic) biocathodes were produced by first enriching graphite fiber brush electrodes as the anodes in sediment-type microbial fuel cells (sMFCs) using two different marine sediments and then electrically inverting the anodes to function as cathodes in two-chamber bioelectrochemical systems (BESs). Electron consumption occurred at set potentials of -439 mV and -539 mV (versus the potential of a standard hydrogen electrode) but not at -339 mV in minimal media lacking organic sources of energy. Results at these different potentials were consistent with separate linear sweep voltammetry (LSV) scans that indicated enhanced activity (current consumption) below only ca. -400 mV. MFC bioanodes not originally acclimated at a set potential produced electron-accepting (electrotrophic) biocathodes, but bioanodes operated at a set potential (+11 mV) did not. CO, was removed from cathode headspace, indicating that the electrotrophic biocathodes were autotrophic. Hydrogen gas generation, followed by loss of hydrogen gas and methane production in one sample, suggested hydrogenotrophic methanogenesis. There was abundant microbial growth in the biocathode chamber, as evidenced by an increase in turbidity and the presence of microorganisms on the cathode surface. Clone library analysis of 16S rRNA genes indicated prominent sequences most similar to those of Eubacterium limosum (Butyribacterium methylotrophicum), Desulfovibrio sp. A2, Rhodococcus opacus, and Gemmata obscuriglobus. Transfer of the suspension to sterile cathodes made of graphite plates, carbon rods, or carbon brushes in new BESs resulted in enhanced current after 4 days, demonstrating growth by these microbial communities on a variety of cathode substrates. This report provides a simple and effective method for enriching autotrophic electrotrophs by the use of sMFCs without the need for set potentials, followed by the use of potentials more negative than -400 mV.

  2. M & V Shootout: Setting the Stage For Testing the Performance of New Energy Baseline

    SciTech Connect (OSTI)

    Touzani, Samir; Custodio, Claudine; Sohn, Michael; Fernandes, Samuel; Granderson, Jessica; Jump, David; Taylor, Cody

    2015-07-01

    Trustworthy savings calculations are critical to convincing investors in energy efficiency projects of the benefit and cost-effectiveness of such investments and their ability to replace or defer supply-side capital investments. However, today’s methods for measurement and verification (M&V) of energy savings constitute a significant portion of the total costs of efficiency projects. They also require time-consuming data acquisition and often do not deliver results until years after the program period has ended. A spectrum of savings calculation approaches are used, with some relying more heavily on measured data and others relying more heavily on estimated or modeled data, or stipulated information. The rising availability of “smart” meters, combined with new analytical approaches to quantifying savings, has opened the door to conducting M&V more quickly and at lower cost, with comparable or improved accuracy. Energy management and information systems (EMIS) technologies, not only enable significant site energy savings, but are also beginning to offer M&V capabilities. This paper expands recent analyses of public-domain, whole-building M&V methods, focusing on more novel baseline modeling approaches that leverage interval meter data. We detail a testing procedure and metrics to assess the performance of these new approaches using a large test dataset. We also provide conclusions regarding the accuracy, cost, and time trade-offs between more traditional M&V and these emerging streamlined methods. Finally, we discuss the potential evolution of M&V to better support the energy efficiency industry through low-cost approaches, and the long-term agenda for validation of building energy analytics.

  3. Effect of Strong Acid Functional Groups on Electrode Rise Potential in Capacitive Mixing by Double Layer Expansion

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hatzell, Marta C.; Raju, Muralikrishna; Watson, Valerie J.; Stack, Andrew G.; van Duin, Adri C. T.; Logan, Bruce E.

    2014-11-03

    We report that the amount of salinity-gradient energy that can be obtained through capacitive mixing based on double layer expansion depends on the extent the electric double layer (EDL) is altered in a low salt concentration (LC) electrolyte (e.g., river water). We show that the electrode-rise potential, which is a measure of the EDL perturbation process, was significantly (P = 10–5) correlated to the concentration of strong acid surface functional groups using five types of activated carbon. Electrodes with the lowest concentration of strong acids (0.05 mmol g–1) had a positive rise potential of 59 ± 4 mV in themore » LC solution, whereas the carbon with the highest concentration (0.36 mmol g–1) had a negative rise potential (₋31 ± 5 mV). Chemical oxidation of a carbon (YP50) using nitric acid decreased the electrode rise potential from 46 ± 2 mV (unaltered) to ₋6 ± 0.5 mV (oxidized), producing a whole cell potential (53 ± 1.7 mV) that was 4.4 times larger than that obtained with identical electrode materials (from 12 ± 1 mV). Changes in the EDL were linked to the behavior of specific ions in a LC solution using molecular dynamics and metadynamics simulations. The EDL expanded in the LC solution when a carbon surface (pristine graphene) lacked strong acid functional groups, producing a positive-rise potential at the electrode. In contrast, the EDL was compressed for an oxidized surface (graphene oxide), producing a negative-rise electrode potential. In conclusion, these results established the linkage between rise potentials and specific surface functional groups (strong acids) and demonstrated on a molecular scale changes in the EDL using oxidized or pristine carbons.« less

  4. Meet the CAMS Staff

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    meet the cams staff Meet the CAMS Staff Members of the CAMS staff standing near the 10 MV Tandem Van de Graaff Accelerator at CAMS, Lawrence Livermore National Laboratory. Members of the CAMS staff standing near the 10 MV Tandem Van de Graaff Accelerator at CAMS, Lawrence Livermore National Laboratory. Name Title E-mail Phone Graham Bench Director bench1@llnl.gov +1-925-423-5155 Thomas A. Brown Scientific Staff tabrown@llnl.gov +1-925-423-8507 Bruce Buchholz Scientific Staff bbuchholz@llnl.gov

  5. Megavoltage imaging with a photoconductor based sensor

    DOE Patents [OSTI]

    Partain, Larry Dean; Zentai, George

    2011-02-08

    A photodetector for detecting megavoltage (MV) radiation comprises a semiconductor conversion layer having a first surface and a second surface disposed opposite the first surface, a first electrode coupled to the first surface, a second electrode coupled to the second surface, and a low density substrate including a detector array coupled to the second electrode opposite the semiconductor conversion layer. The photodetector includes a sufficient thickness of a high density material to create a sufficient number of photoelectrons from incident MV radiation, so that the photoelectrons can be received by the conversion layer and converted to a sufficient of recharge carriers for detection by the detector array.

  6. Fundamental Research in Superconducting RF Cavity Design

    SciTech Connect (OSTI)

    Georg Hoffstaetter

    2012-11-13

    This is a 3-year SRF R&D proposal with two main goals: 1) to benefit near term high gradient SRF applications by understanding the causes of quench at high fields in present-day niobium cavities 2) to open the long-range prospects for SRF applications by experimentally verifying the recent exciting theoretical predication for new cavity materials such as Nb3Sn and MgB2. These predictions shwo that ultimately gradients of 100Mv/m to 200MV/m may become possible as material imperfections are overcome.

  7. Kondo and mixed-valence regimes in multilevel quantum dots

    SciTech Connect (OSTI)

    Chudnovskiy, A. L.; Ulloa, S. E.

    2001-04-15

    We investigate the dependence of the ground state of a multilevel quantum dot on the coupling to an external fermionic system and on the interactions in the dot. As the coupling to the external system increases, the rearrangement of the effective energy levels in the dot signals the transition from the Kondo regime to a mixed-valence (MV) regime. The MV regime in a two-level dot is characterized by an intrinsic mixing of the levels in the dot, resulting in nonperturbative subtunneling and supertunneling phenomena that strongly influence the Kondo effect.

  8. Microsoft Word - S05827_WCR_Final.doc

    Office of Legacy Management (LM)

    MV-4 Data This page intentionally left blank U.S. Department of Energy Well Completion Report for CAU 443 CNTA December 2009 Doc. No. S05827 Page B-1 Table B-1. MV-4 Chronology Date Time Depth (ft bgs) Activity 04/16/09 through 04/22/09 NA NA Mobilization to CNTA and rig-up to drill 04/22/09 15:45 0 Rig inspection and drill pad walk through inspection, continue with preparations for drilling. 04/22/09 21:50 0 Begin drilling 31-inch diameter conductor casing borehole 04/23/09 10:10 100 Advanced

  9. Hybrid Back Surface Reflector GaInAsSb Thermophotovoltaic Devices

    SciTech Connect (OSTI)

    RK Huang; CA Wang; MK Connors; GW Turner; M Dashiell

    2004-05-11

    Back surface reflectors have the potential to improve thermophotovoltaic (TPV) device performance though the recirculation of infrared photons. The ''hybrid'' back-surface reflector (BSR) TPV cell approach allows one to construct BSRs for TPV devices using conventional, high efficiency, GaInAsSb-based TPV material. The design, fabrication, and measurements of hybrid BSR-TPV cells are described. The BSR was shown to provide a 4 mV improvement in open-circuit voltage under a constant shortcircuit current, which is comparable to the 5 mV improvement theoretically predicted. Larger improvements in open-circuit voltage are expected in the future with materials improvements.

  10. CAMS Capabilities

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    cams capabilities CAMS Capabilities HVEC 10 MV Model FN Tandem Of the three accelerators CAMS utilizes the largest is the HVEC 10 MV Model FN Tandem, which was obtained from the University of Washington and installed at LLNL in the mid-80s. During installation the accelerator's belt charging system was replaced with a NEC Pelletron, new Dowlish spiral-inclined beam tubes were installed, as were the gas-handling systems necessary for use of SF6 as the insulating tank gas. The FN accelerator is

  11. Preliminary PBFA II design

    SciTech Connect (OSTI)

    Johnson, D. L.; VanDevender, J. P.; Martin, T. H.

    1980-01-01

    The upgrade of Sandia National Laboratories particle beam fusion accelerator, PBFA I, to PBFA II presents several interesting and challenging pulsed power design problems. PBFA II requires increasing the PBFA I output parameters from 2 MV, 30 TW, 1 MJ to 4 MV, 100 TW, 3.5 MJ with the constraint of using much of the same PBFA I hardware. The increased PBFA II output will be obtained by doubling the number of modules (from 36 to 72), increasing the primary energy storage (from 4 MJ to 15 MJ), lowering the pulse forming line (PFL) output impedance, and adding a voltage doubling network.

  12. Josephson tunnel junctions with chemically vapor deposited polycrystalline germanium barriers

    SciTech Connect (OSTI)

    Kroger, H.; Jillie, D.W.; Smith, L.N.; Phaneuf, L.E.; Potter, C.N.; Shaw, D.M.; Cukauskas, E.J.; Nisenoff, M.

    1984-03-01

    High quality Josephson tunnel junctions have been fabricated whose tunneling barrier is polycrystalline germanium chemically vapor deposited on a NbN base electrode and covered by a Nb counterelectrode. These junctions have excellent characteristics for device applications: values of V/sub m/ (the product of the critical current and the subgap resistance measured at 2 mV and 4.2 K) ranging between 35--48 mV, ideal threshold curves, a steep current rise at the gap voltage, and Josephson current densities from 100 to 1100 A/cm/sup 2/.

  13. SU-E-T-583: Optimizing the MLC Model Parameters for IMRT in the RayStation Treatment Planning System

    SciTech Connect (OSTI)

    Chen, S; Yi, B; Xu, H; Yang, X; Prado, K; D'Souza, W

    2014-06-01

    Purpose: To optimize the MLC model parameters for IMRT in the RayStation v.4.0 planning system and for a Varian C-series Linac with a 120-leaf Millennium MLC. Methods: The RayStation treatment planning system models rounded leaf-end MLC with the following parameters: average transmission, leaf-tip width, tongue-and-groove, and position offset. The position offset was provided by Varian. The leaf-tip width was iteratively evaluated by comparing computed and measured transverse dose profiles of MLC-defined fields at dmax in water. The profile comparison was also used to verify the MLC position offset. The transmission factor and leaf tongue width were derived iteratively by optimizing five clinical patient IMRT QA Results: brain, lung, pancreas, head-and-neck (HN), and prostate. The HN and prostate cases involved splitting fields. Verifications were performed with Mapcheck2 measurements and Monte Carlo calculations. Finally, the MLC model was validated using five test IMRT cases from the AAPM TG119 report. Absolute gamma analyses (3mm/3% and 2mm/2%) were applied. In addition, computed output factors for MLC-defined small fields (22, 33, 44, 66cm) of both 6MV and 18MV were compared to those measured by the Radiological Physics Center (RPC). Results: Both 6MV and 18MV models were determined to have the same MLC parameters: 2.5% transmission, tongue-and-groove 0.05cm, and leaftip 0.3cm. IMRT QA analysis for five cases in TG119 resulted in a 100% passing rate with 3mm/3% gamma analysis for 6MV, and >97.5% for 18MV. With 2mm/2% gamma analysis, the passing rate was >94.6% for 6MV and >90.9% for 18MV. The difference between computed output factors in RayStation and RPC measurements was less than 2% for all MLCdefined fields, which meets the RPC's acceptance criterion. Conclusion: The rounded leaf-end MLC model in RayStation 4.0 planning system was verified and IMRT commissioning was clinically acceptable. The IMRT commissioning was well validated using guidance from the

  14. CX-005298: Categorical Exclusion Determination | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    8: Categorical Exclusion Determination CX-005298: Categorical Exclusion Determination Vehicle Production Group LLC, MV-1 Assembly Facility CX(s) Applied: B1.31, B5.1 Date: 09/23/2010 Location(s): Mishawaka, Indiana Office(s): Advanced Technology Vehicles Manufacturing Loan Program, Loan Guarantee Program Office The Department of Energy's (DOE) proposed action is to issue a loan to The Vehicle Production Group LLC (VPG) for an MV-I vehicle, the assembly of which would take place in an existing

  15. Technetium Sorption by Cementitious Materials Under Reducing Conditions

    SciTech Connect (OSTI)

    Kaplan, Daniel I.; Estes, Shanna L.; Powell, Brian A.

    2012-09-28

    The objective of this study was to measure technetium ({sup 99}Tc) sorption to cementitious materials under reducing conditions to simulate Saltstone Disposal Facility conditions. {sup 99}Tc(VII) batch sorption experiments were conducted for 319 days in an inert glovebag with a variety of cementitious materials (aged cement, Vault 2, TR545, and TR547) containing varying amounts of blast furnace slag. Between 154 and 319 days, the {sup 99}Tc aqueous concentrations tended to remain constant and samples amended with different initial {sup 99}Tc concentrations, tended to merge at about 10{sup -9} M for Vault 2 (17% slag) and TR545 (90% slag) and 10{sup -8} M for TR547 (45% slag). This data provided strong evidence that solubility, and not adsorption (K{sub d} values), was controlling aqueous {sup 99}Tc concentrations. Laboratory data superimposed over thermodynamic speciation diagrams further supported the conclusion that solubility, and not adsorption controlled {sup 99}Tc aqueous concentrations. The oxidation state of the aqueous {sup 99}Tc at the end of the sorption experiment was determined by solvent extraction to be almost entirely {sup 99}Tc(VII). The pH of the present system was ~11.8. Previously proposed solubility controlling phases including Tc-sulfides may be present, but do not appear to control solubility. After the 319 day sorption period, the suspensions were removed from the glovebag and a desorption step under oxic conditions was conducted for 20 days by adding oxic, pH-buffered solutions to the suspensions. {sup 99}Tc aqueous concentrations increased by more than an order of magnitude and Eh increased by several hundred millivolts within 24 hours after the introduction of the oxic solutions. These desorption results are consistent with re-oxidation and dissolution/desorption of {sup 99}Tc(IV) phases possibly present in the cementitious materials after the anoxic sorption step of the experiment. Aqueous {sup 99}Tc concentrations continued to increase

  16. Novel, electrolyte solutions comprising fully inorganic salts with high anodic stability for rechargeable magnesium batteries

    SciTech Connect (OSTI)

    Doe, RE; Han, R; Hwang, J; Gmitter, AJ; Shterenberg, I; Yoo, HD; Pour, N; Aurbach, D

    2014-01-01

    Herein the first inorganic magnesium salt solution capable of highly reversible magnesium electrodeposition is presented. Synthesized by acid-base reaction of MgCl2 and Lewis acidic compounds such as AlCl3, this salt class demonstrates upwards of 99% Coulombic efficiency, deposition overpotential of <200 mV, and anodic stability of 3.1 V.

  17. AMO FOA Targets Advanced Components for Next-Generation Electric Machines

    Broader source: Energy.gov [DOE]

    AMO’s Next Generation Electric Machines (NGEM) program announced up to $20 million is now available to develop a new generation of energy efficient, high power density, high speed integrated medium voltage (MV) drive systems for a wide variety of critical energy applications.

  18. Design of RF Feed System for Standing-Wave Accelerator Structures

    SciTech Connect (OSTI)

    Neilson, J.; Tantawi, S.; Dolgashev, V.; /SLAC

    2012-05-25

    We are investigating a standing wave accelerator structure that uses a rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

  19. Road Map for Studies to Produce Consistent and High Performance SRF Accelerator Structures

    SciTech Connect (OSTI)

    Ganapati Rao Myneni; John F. OHanlon

    2007-06-20

    Superconducting Radio Frequency (SRF) accelerator structures made from high purity niobium are becoming the technological choice for a large number of future accelerators and energy recovery LINACs (ERL). Most of the presently planned accelerators and ERL requirements will be met with some effort by the current SRF technology where accelerating gradients of about 20 MV/m can be produced on a routine basis with an acceptable yield. However, the XFEL at DESY and the planned ILC require acceleration gradients more than 28 MV/m and 35 MV/m respectively. At the recent ILC meeting at Snowmass (2005) concern was expressed regarding the wide spread in the achieved accelerator gradients and the relatively low yields. For obtaining accelerating gradients of 35 MV/m in SRF accelerator structures consistently, a deeper understanding of the causes for the spread has to be gained and advances have to be made in many scientific and high technology fields, including materials, surface and vacuum sciences, application of reliable processes and procedures, which provide contamination free surfaces and avoid recontamination and cryogenics related technologies. In this contribution a road map for studies needed to produce consistent and high performance SRF accelerator structures from the needed materials development to clean and non-recontaminating processes and procedures will be presented.

  20. Advanced Distributor Products: Noncompliance Determination (2010-SE-0304)

    Broader source: Energy.gov [DOE]

    DOE issued a Notice of Noncompliance Determination to Advanced Distributor Products finding that basic model N2H348A(G)KB* + H,GE50560 + *8MPV125 and basic model N2H360A(G)KB* + H,GE50560 + MV16J22**B* do not comport with the energy conservation standards.

  1. Q0 Improvement of Large-Grain Multi-Cell Cavities by Using JLab's Standard ILC EP Processing

    SciTech Connect (OSTI)

    Geng, R. L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Eremeev, G. V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kneisel, P. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Liu, K. X. [IHIP, Peking University, Beijing (China); Lu, X. Y. [IHIP, Peking University, Beijing (China); Zhao, K. [IHIP, Peking University, Beijing (China)

    2011-07-01

    As reported previously at the Berlin workshop, applying the JLab standard ILC electropolishing (EP) recipe on previously buffered chemical polishing (BCP) etched fine-grain multi-cell cavities results in improvement both in gradient and Q{sub 0}. We recently had the opportunity to experiment with two 1300 MHz 9-cell large-gain niobium cavities manufactured by JLab and Peking University. Both cavities were initially BCP etched and further processed by using JLab's standard ILC EP recipe. Due to fabrication defects, these two cavities only reached a gradient in the range of 20-30 MV/m. Interestingly both cavities demonstrated significant Q{sub 0} improvement in the gradient range of 15-20 MV/m. At 2K, a Q{sub 0} value of 2E10 is achieved at 20 MV/m. At a reduced temperature of 1.8K, a Q{sub 0} value of 3E10 is achieved at 20 MV/m. These results suggest that a possible path for obtaining higher Q{sub 0} in the medium gradient range is to use the large-grain material for cavity fabrication and EP and low temperature bake for cavity processing.

  2. Multipacting-free quarter-wavelength choke joint design for BNL SRF

    SciTech Connect (OSTI)

    Xu, W.; Belomestnykh, S.; Ben-Zvi, I.; Liaw, C. J.; Smith, K.; Than, R.; Tuozzolo, J.; Wang, E.; Weiss, D.; Zaltsman, A.

    2015-05-03

    The BNL SRF gun cavity operated well in CW mode up to 2 MV. However, its performance suffered due to multipacting in the quarter-wavelength choke joint. A new multipacting-free cathode stalk was designed and conditioned. This paper describes RF and thermal design of the new cathode stalk and its conditioning results.

  3. Alluvial Groundwater -- Upgradient -- 92-05&

    Office of Legacy Management (LM)

    ... Measurements Alkalinity mgL 302 370 291 250 362 276 Conductivity c mhoscm 1894 1947 1670 1605 1752 2295 DO c mgL 4.35 6.01 -- 2.33 -- -- ORP c mV 151 123.5 93 105.2 75 64 ...

  4. Microsoft Word - S06596_GW.doc

    Office of Legacy Management (LM)

    ... Alkalinity mgL 302 370 291 250 362 276 337 186 Conductivity c mhoscm 1894 1947 1670 1605 1752 2295 1875 1521 DO c mgL 4.35 6.01 -- 2.33 -- -- -- -- ORP c mV 151 ...

  5. Microsoft Word - S03623_2007AnnRep_091007.doc

    Office of Legacy Management (LM)

    ... Field Measurements Alkalinity mgL 302 370 Conductivity c mhoscm 1894 1947 DO c mgL 4.35 6.01 ORP c mV 151 123.5 pH c s.u. 6.86 7.06 Temperature c C 14.36 8.90 ...

  6. Design of RF Feed System for Standing-Wave Accelerator Structures

    SciTech Connect (OSTI)

    Neilson, Jeffrey; Tantawi, Sami; Dolgashev, Valery

    2010-11-04

    We are investigating a standing wave structure with an rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

  7. Slide 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    New Custom Programs: Pre-Approved M&V and Evaluated Custom Program March 2011 Summer Goodwin Lauren Gage B O N N E V I L L E P O W E R A D M I N I S T R A T I O N 2 Goal of the...

  8. How do I know if my RTUs are Efficient? When do I Replace or Retrofit them?

    Broader source: Energy.gov [DOE]

    Because roof top unit (RTU) air conditioners have such long useful lifetimes, building owners/managers don’t always know the best way to optimize them. The Advanced RTU Campaign offers an Evaluation Methodology that ranges from an initial RTU inventory through analysis, procurement, and M&V.

  9. Performance of a CEBAF production cavity after high-temperature heat treatment

    SciTech Connect (OSTI)

    Kneisel, P.; Rao, M.

    1993-06-01

    CEBAF`s production cavities are tested in a vertical configuration after appropriate chemical surface treatment prior to installation into the accelerator. The performance of these cavities is excellent, often exceeding the specifications of E{sub acc}=5 MV/m at 2 K by factors of 2 to 3. In such cases the cavities are often limited by thermal-magnetic breakdown. A cavity that exhibited a limiting gradient of E{sub acc} {le} 16.4 MV/m has been heat-treated at 1400{degrees}C for 6 hours in the presence of titanium as a solid state gettering material to improve the thermal stability of the niobium. After the heat treatment a gradient of E{sub acc}=20.5 MV/m corresponding to a peak surface electric field of E{sub peak}=52 MV/m has been measured. In addition to the cavity results, data on thermal conductivity and tensile properties of samples which have undergone the same treatments as the cavity are reported.

  10. Y

    Office of Legacy Management (LM)

    . - - 0' Y j MO . I-3 % V. B&m, MvUlen at Rmt BfterWa %lBh.%ron I, B. Dauling, M- ?d muh& Mvirr;iaa 08lt M&a OpuFdlwn c&m YxZfXBUWl7Wzllltsl AT&T. XoUIs anrwlllif +t3&v: s...

  11. SU-E-T-110: Development of An Independent, Monte Carlo, Dose Calculation, Quality Assurance Tool for Clinical Trials

    SciTech Connect (OSTI)

    Faught, A; Davidson, S; Kry, S; Ibbott, G; Followill, D; Fontenot, J; Etzel, C

    2014-06-01

    Purpose: To develop a comprehensive end-to-end test for Varian's TrueBeam linear accelerator for head and neck IMRT using a custom phantom designed to utilize multiple dosimetry devices. Purpose: To commission a multiple-source Monte Carlo model of Elekta linear accelerator beams of nominal energies 6MV and 10MV. Methods: A three source, Monte Carlo model of Elekta 6 and 10MV therapeutic x-ray beams was developed. Energy spectra of two photon sources corresponding to primary photons created in the target and scattered photons originating in the linear accelerator head were determined by an optimization process that fit the relative fluence of 0.25 MeV energy bins to the product of Fatigue-Life and Fermi functions to match calculated percent depth dose (PDD) data with that measured in a water tank for a 10x10cm2 field. Off-axis effects were modeled by a 3rd degree polynomial used to describe the off-axis half-value layer as a function of off-axis angle and fitting the off-axis fluence to a piecewise linear function to match calculated dose profiles with measured dose profiles for a 4040cm2 field. The model was validated by comparing calculated PDDs and dose profiles for field sizes ranging from 33cm2 to 3030cm2 to those obtained from measurements. A benchmarking study compared calculated data to measurements for IMRT plans delivered to anthropomorphic phantoms. Results: Along the central axis of the beam 99.6% and 99.7% of all data passed the 2%/2mm gamma criterion for 6 and 10MV models, respectively. Dose profiles at depths of dmax, through 25cm agreed with measured data for 99.4% and 99.6% of data tested for 6 and 10MV models, respectively. A comparison of calculated dose to film measurement in a head and neck phantom showed an average of 85.3% and 90.5% of pixels passing a 3%/2mm gamma criterion for 6 and 10MV models respectively. Conclusion: A Monte Carlo multiple-source model for Elekta 6 and 10MV therapeutic x-ray beams has been developed as a quality

  12. Optimization of leaf margins for lung stereotactic body radiotherapy using a flattening filter-free beam

    SciTech Connect (OSTI)

    Wakai, Nobuhide; Sumida, Iori; Otani, Yuki; Suzuki, Osamu; Seo, Yuji; Isohashi, Fumiaki; Yoshioka, Yasuo; Ogawa, Kazuhiko; Hasegawa, Masatoshi

    2015-05-15

    Purpose: The authors sought to determine the optimal collimator leaf margins which minimize normal tissue dose while achieving high conformity and to evaluate differences between the use of a flattening filter-free (FFF) beam and a flattening-filtered (FF) beam. Methods: Sixteen lung cancer patients scheduled for stereotactic body radiotherapy underwent treatment planning for a 7 MV FFF and a 6 MV FF beams to the planning target volume (PTV) with a range of leaf margins (?3 to 3 mm). Forty grays per four fractions were prescribed as a PTV D95. For PTV, the heterogeneity index (HI), conformity index, modified gradient index (GI), defined as the 50% isodose volume divided by target volume, maximum dose (Dmax), and mean dose (Dmean) were calculated. Mean lung dose (MLD), V20 Gy, and V5 Gy for the lung (defined as the volumes of lung receiving at least 20 and 5 Gy), mean heart dose, and Dmax to the spinal cord were measured as doses to organs at risk (OARs). Paired t-tests were used for statistical analysis. Results: HI was inversely related to changes in leaf margin. Conformity index and modified GI initially decreased as leaf margin width increased. After reaching a minimum, the two values then increased as leaf margin increased (V shape). The optimal leaf margins for conformity index and modified GI were ?1.1 0.3 mm (mean 1 SD) and ?0.2 0.9 mm, respectively, for 7 MV FFF compared to ?1.0 0.4 and ?0.3 0.9 mm, respectively, for 6 MV FF. Dmax and Dmean for 7 MV FFF were higher than those for 6 MV FF by 3.6% and 1.7%, respectively. There was a positive correlation between the ratios of HI, Dmax, and Dmean for 7 MV FFF to those for 6 MV FF and PTV size (R = 0.767, 0.809, and 0.643, respectively). The differences in MLD, V20 Gy, and V5 Gy for lung between FFF and FF beams were negligible. The optimal leaf margins for MLD, V20 Gy, and V5 Gy for lung were ?0.9 0.6, ?1.1 0.8, and ?2.1 1.2 mm, respectively, for 7 MV FFF compared to ?0.9 0.6, ?1.1 0

  13. Use of Quantitative Uncertainty Analysis to Support M&VDecisions in ESPCs

    SciTech Connect (OSTI)

    Mathew, Paul A.; Koehling, Erick; Kumar, Satish

    2005-05-11

    Measurement and Verification (M&V) is a critical elementof an Energy Savings Performance Contract (ESPC) - without M&V, thereisno way to confirm that the projected savings in an ESPC are in factbeing realized. For any given energy conservation measure in an ESPC,there are usually several M&V choices, which will vary in terms ofmeasurement uncertainty, cost, and technical feasibility. Typically,M&V decisions are made almost solely based on engineering judgmentand experience, with little, if any, quantitative uncertainty analysis(QUA). This paper describes the results of a pilot project initiated bythe Department of Energy s Federal Energy Management Program to explorethe use of Monte-Carlo simulation to assess savings uncertainty andthereby augment the M&V decision-making process in ESPCs. The intentwas to use QUA selectively in combination with heuristic knowledge, inorder to obtain quantitative estimates of the savings uncertainty withoutthe burden of a comprehensive "bottoms-up" QUA. This approach was used toanalyze the savings uncertainty in an ESPC for a large federal agency.The QUA was seamlessly integrated into the ESPC development process andthe incremental effort was relatively small with user-friendly tools thatare commercially available. As the case study illustrates, in some casesthe QUA simply confirms intuitive or qualitative information, while inother cases, it provides insight that suggests revisiting the M&Vplan. The case study also showed that M&V decisions should beinformed by the portfolio risk diversification. By providing quantitativeuncertainty information, QUA can effectively augment the M&Vdecision-making process as well as the overall ESPC financialanalysis.

  14. Comments on shielding for dual energy accelerators

    SciTech Connect (OSTI)

    Rossi, M. C.; Lincoln, H. M.; Quarin, D. J.; Zwicker, R. D.

    2008-06-15

    Determination of shielding requirements for medical linear accelerators has been greatly facilitated by the publication of the National Council on Radiation Protection and Measurements (NCRP) latest guidelines on this subject in NCRP Report No. 151. In the present report the authors review their own recent experience with patient treatments on conventional dual energy linear accelerators to examine the various input parameters needed to follow the NCRP guidelines. Some discussion is included of workloads, occupancy, use factors, and field size, with the effects of intensity modulated radiotherapy (IMRT) treatments included. Studies of collimator settings showed average values of 13.1x16.2 cm{sup 2} for 6 MV and 14.1x16.8 cm{sup 2} for 18 MV conventional ports, and corresponding average unblocked areas of 228 and 254 cm{sup 2}, respectively. With an average of 77% of the field area unblocked, this gives a mean irradiated area of 196 cm{sup 2} for the 18 MV beam, which dominates shielding considerations for most dual energy machines. Assuming conservatively small room dimensions, a gantry bin angle of 18 deg. was found to represent a reasonable unit for tabulation of use factors. For conventional 18 MV treatments it was found that the usual treatment angles of 0, 90, 180, and 270 deg. were still favored, and use factors of 0.25 represent reasonable estimates for these beams. As expected, the IMRT fields (all at 6 MV) showed a high degree of gantry angle randomization, with no bin having a use factor in excess of 0.10. It is concluded that unless a significant number of patients are treated with high energy IMRT, the traditional use factors of 0.25 are appropriate for the dominant high energy beam.

  15. Dosimetric characterization of the iBEAM evo carbon fiber couch for radiotherapy

    SciTech Connect (OSTI)

    Smith, David W.; Christophides, Damianos; Dean, Christopher; Naisbit, Mitchell; Mason, Joshua; Morgan, Andrew

    2010-07-15

    Purpose: This study characterizes the dosimetric properties of the iBEAM evo carbon fiber couch manufactured by Medical Intelligence and examines the accuracy of the CMS XiO and Nucletron Oncentra Masterplan (OMP) treatment planning systems for calculating beam attenuation due to the presence of the couch. Methods: To assess the homogeneity of the couch, it was CT scanned at isocentric height and a number of signal intensity profiles were generated and analyzed. To simplify experimental procedures, surface dose and central axis depth dose measurements were performed in a solid water slab phantom using Gafchromic film for 6 and 10 MV photon beams at gantry angles of 0 deg. (normal incidence), 30 deg., and 60 deg. with an inverted iBEAM couch placed on top of the phantom. Attenuation measurements were performed in a cylindrical solid water phantom with an ionization chamber positioned at the isocenter. Measurements were taken for gantry angles from 0 deg. to 90 deg. in 10 deg. increments for both 6 and 10 MV photon beams. This setup was replicated in the XiO and OMP treatment planning systems. Dose was calculated using the pencil beam, collapsed cone, convolution, and superposition algorithms. Results: The CT scan of the couch showed that it was uniformly constructed. Surface dose increased by (510{+-}30)% for a 6 MV beam and (600{+-}20)% for a 10 MV beam passing through the couch at normal incidence. Obliquely incident beams resulted in a higher surface dose compared to normally incident beams for both open fields and fields with the couch present. Depth dose curves showed that the presence of the couch resulted in an increase in dose in the build up region. For 6 and 10 MV beams incident at 60 deg., nearly all skin sparing was lost. Attenuation measurements derived using the ionization chamber varied from 2.7% (0 deg.) to a maximum of 4.6% (50 deg.) for a 6 MV beam and from 1.9% (0 deg.) to a maximum of 4.0% (50 deg.) for a 10 MV beam. The pencil beam and

  16. Imaging a moving lung tumor with megavoltage cone beam computed tomography

    SciTech Connect (OSTI)

    Gayou, Olivier Colonias, Athanasios

    2015-05-15

    Purpose: Respiratory motion may affect the accuracy of image guidance of radiation treatment of lung cancer. A cone beam computed tomography (CBCT) image spans several breathing cycles, resulting in a blurred object with a theoretical size equal to the sum of tumor size and breathing motion. However, several factors may affect this theoretical relationship. The objective of this study was to analyze the effect of tumor motion on megavoltage (MV)-CBCT images, by comparing target sizes on simulation and pretreatment images of a large cohort of lung cancer patients. Methods: Ninety-three MV-CBCT images from 17 patients were analyzed. Internal target volumes were contoured on each MV-CBCT dataset [internal target volume (ITV{sub CB})]. Their extent in each dimension was compared to that of two volumes contoured on simulation 4-dimensional computed tomography (4D-CT) images: the combination of the tumor contours of each phase of the 4D-CT (ITV{sub 4D}) and the volume contoured on the average CT calculated from the 4D-CT phases (ITV{sub ave}). Tumor size and breathing amplitude were assessed by contouring the tumor on each CBCT raw projection where it could be unambiguously identified. The effect of breathing amplitude on the quality of the MV-CBCT image reconstruction was analyzed. Results: The mean differences between the sizes of ITV{sub CB} and ITV{sub 4D} were −1.6 ± 3.3 mm (p < 0.001), −2.4 ± 3.1 mm (p < 0.001), and −7.2 ± 5.3 mm (p < 0.001) in the anterior/posterior (AP), left/right (LR), and superior/inferior (SI) directions, respectively, showing that MV-CBCT underestimates the full target size. The corresponding mean differences between ITV{sub CB} and ITV{sub ave} were 0.3 ± 2.6 mm (p = 0.307), 0.0 ± 2.4 mm (p = 0.86), and −4.0 ± 4.3 mm (p < 0.001), indicating that the average CT image is more representative of what is visible on MV-CBCT in the AP and LR directions. In the SI directions, differences between ITV{sub CB} and ITV{sub ave} could be

  17. Particle Physics at the University of Pittsburgh Summary Report for Proposal Period FY'09-11

    SciTech Connect (OSTI)

    Boudreau, Joe; Dytman, Steven; Mueller, James; Naples, Donna; Paolone, Vittorio; Savinov, Vladimir

    2012-10-01

    Presented is the final summary report for grant DOE-FG02-91ER40646. The HEP group at the University consists of three tasks: B,D and L. Task B supports Pitt's CDF group at the energy frontier which includes Joe Boudreau and Paul Shepard. Work of the group includes Hao Song's thesis on the measurement of the B_c lifetime using exclusive J/psi+pion decays, and an update of the previous B_c semi-leptonic analyses under the supervision of Paul Shepard. Task D supports Pitt's neutrino group at the intensity frontier which includes PIs Dytman, Naples and Paolone. The group also includes postdoctoral research associate Danko, and thesis students Isvan (MINOS), Eberly (Minerva ), Ren (Minerva )and Hansen (T2K). This report summarizes their progress on ongoing experiments which are designed to make significant contributions to a detailed understanding of the neutrino mixing matrix. Task L supports Pitt's ATLAS group at the energy frontier and includes investigators Vladimir Savinov, James Mueller and Joe Boudreau. This group contributed both to hardware (calorimeter electronics, Savinov) and to software (Simulation, Detector Description, and Visualization: Boudreau and Mueller; MC generators: Savinov) and a summary of their progress is presented.

  18. Mass transfer and biodegradation of PAH compounds from coal tar. Quarterly technical report, January--March 1993

    SciTech Connect (OSTI)

    Ramaswami, A.; Ghoshal, S.; Luthy, R.G.

    1994-09-01

    This study examines the role of physico-chemical mass transfer processes on the rate of biotransformation of polycyclic aromatic hydrocarbon (PAH) compounds released from non-aqueous phase liquid (NAPL) coal tar present at residual saturation within a microporous medium. A simplified coupled dissolution-degradation model is developed that describes the concurrent mass transfer and biokinetic processes occurring in the system. Model results indicate that a dimensionless Damkohler number can be utilized to distinguish between systems that are mass transfer limited, and those that are limited by biological phenomena. The Damkohler number is estimated from independent laboratory experiments that measure the rates of aqueous phase dissolution and biodegradation of naphthalene from coal tar. Experimental data for Stroudsburg coal tar imbibed within 236 {mu}m diameter silica particles yield Damkohler numbers smaller than unity, indicating, for the particular system under study, that the overall rate of biotransformation of naphthalene is not limited by the mass transfer of naphthalene from coal tar to the bulk aqueous phase. There is a need for investigation of mass transfer for larger particles and/or other PAH compounds, and study of microbial rate-limiting phenomena including toxicity, inhibition and competitive substrate utilization.

  19. Ther FERMI FEL project at TRIESTE

    SciTech Connect (OSTI)

    Walker, R.P.; Bulfone, D.; Cargnello, F.

    1995-12-31

    The goal of the FERMI project - Free Electron Radiation and Matching Instrumentation - is to construct a new user facility for FEL radiation beams covering a broad spectral range (2-250 {mu}m) to complement the high brightness VUV/Soft-Xray radiation available from the ELETTRA synchrotron radiation facility at Trieste. A unique feature of the project will be the possibility of carrying out {open_quote}pump-probe{close_quote} experiments using synchronized radiation beams from FERMI and ELETTRA on the same sample. The project was launched at a meeting with Italian FEL experts held in Trieste on the 18th November 1994, chaired by C. Rubbia, as a collaboration between Sincrotrone Trieste, ENEA (Frascati), INFN (Frascati) and the University of Naples (Department of Electronic Engineering). The facility will make use of an existing linac, that forms part of the ELETTRA injection system, and a hall into which the beam can be extracted. In addition, for the first phase of the project equipment will be used from the suspended INFN/ENEA {open_quote}SURF{close_quote} FEL experiment, including the undulator, beam transport magnets and optical cavity. In this first International FEL Conference report on the project, we summarize the main features of the project, concentrating in particular on the most recent activities, including: results of measurements of the linac beam in the FEL mode of operation, further studies of the electron beam transport system including possibilities for bunch length manipulations, and further numerical calculations of the FEL performance.

  20. P-SV conversions at a shallow boundary beneath Campi Flegrei caldera (Italy) - evidence for the magma chamber

    SciTech Connect (OSTI)

    Ferrucci, F.; Hirn, A.; De Natale, G.; Virieux, J.; Mirabile, L. Inst. de Physique du Globe, Paris Osservatorio Vesuviano, Naples CNRS, Inst. de Geodynamique, Valbonne Ist. Universitario Navale, Naples )

    1992-10-01

    Seismograms from an active seismic experiment carried out at Campi Flegrei caldera (near Naples, Italy), show a large-amplitude SV-polarized shear wave, following by less than 1.5-s P waves reflected at wide angle from a deep crustal interface. Early arriving SV-polarized waves, with the same delay to direct P waves, are also observed in seismograms from a regional 280 km-deep, magnitude 5.1 earthquake. Such short delays of S to P waves are consistent with a P-SV conversion on transmission occurring at a shallow boundary beneath the receivers. The large amplitude of the converted-SV phase, along with that the P waves are near vertical, requires a boundary separating a very low rigidity layer from the upper caldera fill. The converted phases are interpreted as a seismic marker of a magma chamber. The top of this magma chamber is located slightly deeper than the deepest earthquakes observed during the 1982-1984 unrest of Campi Flegrei. 8 refs.

  1. Sorption of colloids, organics, and metals onto gas-water interfaces: Transport mechanisms and potential remediation technology. 1998 annual progress report

    SciTech Connect (OSTI)

    Wan, J.; Tokunaga, T.K.

    1998-06-01

    'Although contaminant sorption at mineral surfaces has received much recognition as a major mechanism controlling contaminant behavior in subsurface environments, virtually no attention has been given to the possibility of contaminant sorption at gas-water interfaces. Moreover, no effort has yet been advanced to optimize such interactions for the purpose of facilitating in-situ remediation. Gas-water interfaces, unlike water-solid interfaces, are mobile. Therefore, associations of contaminants with gas-water interfaces can be very important not only in subsurface contaminant distributions, but also in contaminant transport, and potentially in remediation. The first objective of this research is to develop a quantitative understanding of interactions between contaminants and gas-water interfaces. The anticipated results will provide insights into the poorly understood phenomenon of contaminant interactions with the gas-water interface, and improve the current conceptual models of contaminant behavior in subsurface environments. The second purpose of this research is to explore the possibility of using surfactant stabilized microbubbles for in-situ remediation. Both pump-and-treat, and air sparging remediation methods are ineffective at displacing contaminants in zones which are advectively inaccessible. Stable microbubbles can migrate beyond preferential flow pathways and enter lower permeability zones by buoyant rise. The microbubbles can deliver oxygen and nutrients for promoting aerobic degradation of organic contaminants, and also deliver surfactants for emulsifying NAPLs.'

  2. Improved quality of intrafraction kilovoltage images by triggered readout of unexposed frames

    SciTech Connect (OSTI)

    Poulsen, Per Rugaard; Jonassen, Johnny; Jensen, Carsten; Schmidt, Mai Lykkegaard

    2015-11-15

    Purpose: The gantry-mounted kilovoltage (kV) imager of modern linear accelerators can be used for real-time tumor localization during radiation treatment delivery. However, the kV image quality often suffers from cross-scatter from the megavoltage (MV) treatment beam. This study investigates readout of unexposed kV frames as a means to improve the kV image quality in a series of experiments and a theoretical model of the observed image quality improvements. Methods: A series of fluoroscopic images were acquired of a solid water phantom with an embedded gold marker and an air cavity with and without simultaneous radiation of the phantom with a 6 MV beam delivered perpendicular to the kV beam with 300 and 600 monitor units per minute (MU/min). An in-house built device triggered readout of zero, one, or multiple unexposed frames between the kV exposures. The unexposed frames contained part of the MV scatter, consequently reducing the amount of MV scatter accumulated in the exposed frames. The image quality with and without unexposed frame readout was quantified as the contrast-to-noise ratio (CNR) of the gold marker and air cavity for a range of imaging frequencies from 1 to 15 Hz. To gain more insight into the observed CNR changes, the image lag of the kV imager was measured and used as input in a simple model that describes the CNR with unexposed frame readout in terms of the contrast, kV noise, and MV noise measured without readout of unexposed frames. Results: Without readout of unexposed kV frames, the quality of intratreatment kV images decreased dramatically with reduced kV frequencies due to MV scatter. The gold marker was only visible for imaging frequencies ≥3 Hz at 300 MU/min and ≥5 Hz for 600 MU/min. Visibility of the air cavity required even higher imaging frequencies. Readout of multiple unexposed frames ensured visibility of both structures at all imaging frequencies and a CNR that was independent of the kV frame rate. The image lag was 12.2%, 2

  3. Hydroforming of elliptical cavities

    SciTech Connect (OSTI)

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, Peter

    2015-02-27

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with results of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV/m after buffered chemical polishing (BCP) and up to 42 MV/m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30–35 MV/m were measured after BCP and Eacc up to 40 MV/m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc = 30–35 MV/m. One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double

  4. Hydroforming of elliptical cavities

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singer, W.; Singer, X.; Jelezov, I.; Kneisel, Peter

    2015-02-27

    Activities of the past several years in developing the technique of forming seamless (weldless) cavity cells by hydroforming are summarized. An overview of the technique developed at DESY for the fabrication of single cells and multicells of the TESLA cavity shape is given and the major rf results are presented. The forming is performed by expanding a seamless tube with internal water pressure while simultaneously swaging it axially. Prior to the expansion the tube is necked at the iris area and at the ends. Tube radii and axial displacements are computer controlled during the forming process in accordance with resultsmore » of finite element method simulations for necking and expansion using the experimentally obtained strain-stress relationship of tube material. In cooperation with industry different methods of niobium seamless tube production have been explored. The most appropriate and successful method is a combination of spinning or deep drawing with flow forming. Several single-cell niobium cavities of the 1.3 GHz TESLA shape were produced by hydroforming. They reached accelerating gradients Eacc up to 35 MV/m after buffered chemical polishing (BCP) and up to 42 MV/m after electropolishing (EP). More recent work concentrated on fabrication and testing of multicell and nine-cell cavities. Several seamless two- and three-cell units were explored. Accelerating gradients Eacc of 30–35 MV/m were measured after BCP and Eacc up to 40 MV/m were reached after EP. Nine-cell niobium cavities combining three three-cell units were completed at the company E. Zanon. These cavities reached accelerating gradients of Eacc = 30–35 MV/m. One cavity is successfully integrated in an XFEL cryomodule and is used in the operation of the FLASH linear accelerator at DESY. Additionally the fabrication of bimetallic single-cell and multicell NbCu cavities by hydroforming was successfully developed. Several NbCu clad single-cell and double-cell cavities of the TESLA shape have

  5. SU-E-T-625: Use and Choice of Ionization Chambers for the Commissioning of Flattened and Flattening-Filter-Free Photon Beams: Determination of Recombination Correction Factor (ks)

    SciTech Connect (OSTI)

    Stucchi, C; Mongioj, V; Carrara, M; Pignoli, E; Bonfantini, F; Bresolin, A

    2014-06-15

    Purpose: To evaluate the recombination effect for some ionization chambers to be used for linacs commissioning for Flattened Filter (FF) and Flattening Filter Free (FFF) photon beams. Methods: A Varian TrueBeam linac with five photon beams was used: 6, 10 and 15 MV FF and 6 and 10 MV FFF. Measurements were performed in a water tank and in a plastic water phantom with different chambers: a mini-ion chamber (IC CC01, IBA), a plane-parallel ion chamber (IC PPC05, IBA) and two Farmer chambers (NE2581 and FPC05-IBA). Measurement conditions were Source- Surface Distance of 100 cm, two field sizes (10x10 and 40x40 cm2) and five depths (1cm, maximum buildup, 5cm, 10cm and 20cm). The ion recombination factors (kS), obtained from the Jaffe's plots (voltage interval 50-400 V), were evaluated at the recommended operating voltage of +300V. Results: Dose Per Pulse (DPP) at dmax was 0.4 mGy/pulse for FF beams, 1.0 mGy/pulse and 1.9 mGy/pulse for 6MV and 10 MV FFF beams respectively. For all measurement conditions, kS ranged between 0.996 and 0.999 for IC PPC05, 0.997 and 1.008 for IC CC01. For the FPC05 IBA Farmer IC, kS varied from 1.001 to 1.011 for FF beams, from 1.004 to 1.015 for 6 MV FFF and from 1.009 to 1.025 for 10 MV FFF. Whereas, for NE2581 IC the values ranged from 1.002 to 1.009 for all energy beams and measurement conditions. Conclusion: kS depends on the chamber volume and the DPP, which in turn depends on energy beam but is independent of dose rate. Ion chambers with small active volume can be reliably used for dosimetry of FF and FFF beams even without kS correction. On the contrary, for absolute dosimetry of FFF beams by Farmer ICs it is necessary to evaluate and apply the kS correction. Partially supported by Lega Italiana Lotta contro i Tumori (LILT)

  6. Sandia National Laboratories: Z Pulsed Power Facility: How Does the Z

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Machine Work? How Does the Z Machine Work? z-machine i Marx Bank Generator Marx Bank. Each Marx bank has sixty 2.6 μF capacitors (43 nF per Marx when erected) that are charged in parallel and discharged in series. When charged to 85 kV its output voltage is 5.1 MV, and stored energy is 20 MJ for all 36. (For a 90 kV charge it is 5.4 MV and 23 MJ.) When discharged, the peak current of each Marx is about 150 kA with a 1.5 μs time to peak. i Intermediate-Store Capacitor Intermediate-Store

  7. ELECTROCHEMICAL CORROSION REPORT FOR TANKS 241-AW-103 & 241-AZ-102 & 241-AN-106 & 241-AN-107 & 241-AY-101 & 241-AY-102

    SciTech Connect (OSTI)

    DUNCAN JB

    2007-08-22

    Corrosion rates using supernatant samples retrieved from near the top of the liquid layer were determined for the tanks. Corrosion rates using settled solids (saltcake) were determined. The supernatant samples were tested as received without argon sparging. The settled solid sample segments were extruded under anaerobic condition and kept under a sweep of humidified argon gas during 'the electrochemical corrosion testing. The class of steel used to construct the tank in question was used, and test coupons were allowed to equilibrate for a minimum of 18 hours before a Tafel scan was initiated. The coupons were scanned from -250 mV to +250 mV from the rest or open circuit potential. The corrosion rate is reported along with the corrosion current measurement, open circuit potential, and a chi-square statistic generated by the instrument controlling and analysis algorithm.

  8. Recent developments in electropolishing and tumbling R&D at Fermilab

    SciTech Connect (OSTI)

    Cooper, C.; Brandt, J.; Cooley, L.; Ge, M.; Harms, E.; Khabiboulline, T.; Ozelis, J.; Boffo, C.; /Babcock Noell, Wuerzburg

    2009-10-01

    Fermi National Accelerator Lab (Fermilab) is continuing to improve its infrastructure for research and development on the processing of superconducting radio frequency cavities. A single cell 3.9 GHz electropolishing tool built at Fermilab and operated at an industrial partner was recently commissioned. The EP tool was used to produce a single cell 3.9 GHz cavity that reached an accelerating gradient of 30 MV/m with a quality factor of 5 x 10{sup 9}. A single cell 1.3 GHz cavity was also electropolished at the same industrial vendor using the vendor's vertical full-immersion technique. On their first and only attempt the vendor produced a single cell 1.3 GHz cavity that reached 30 MV/m with a quality factor of 1 x 10{sup 10}. These results will be detailed along with preliminary tumbling results.

  9. Operational experience with CW high gradient and high QL cryomodules

    SciTech Connect (OSTI)

    Hovater, J. Curt; Allison, Trent L.; Bachimanchi, Ramakrishna; Daly, Edward F.; Drury, Michael A.; Lahti, George E.; Mounts, Clyde I.; Nelson, Richard M.; Plawski, Tomasz E.

    2014-12-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) energy upgrade from 6 GeV to 12 GeV includes the installation of ten new 100 MV cryomodules (80 cavities). The superconducting RF cavities are designed to operate CW at an accelerating gradient of 19.3 MV/m with a QL of 3×107. The RF system employs single cavity control using new digital LLRF controls and 13 kW klystrons. Recently, all of the new cryomodules and associated RF hardware and software have been commissioned and operated in the CEBAF accelerator. Electrons at linac currents up to 10 ?A have been successfully accelerated and used for nuclear physics experiments. This paper reports on the commissioning and operation of the cryomodules and RF system.

  10. New results of development on high efficiency high gradient superconducting rf cavities

    SciTech Connect (OSTI)

    Geng, Rongli; Li, Z.; Hao, K.; Liu, K.-X.; Zhao, H.-Y.; Adolphsen, C.

    2015-09-01

    We report on the latest results of development on high efficiency high gradient superconducting radio frequency (SRF) cavities. Several 1-cell cavities made of large-grain niobium (Nb) were built, processed and tested. Two of these cavities are of the Low Surface Field (LSF) shape. Series of tests were carried out following controlled thermal cycling. Experiments toward zero-field cooling were carried out. The best experimentally achieved results are Eacc = 41 MV/m at Q0 = 6.5×1010 at 1.4 K by a 1-cell 1.3 GHz large-grain Nb TTF shape cavity and Eacc = 49 MV/m at Q0 = 1.5×1010 at 1.8 K by a 1-cell 1.5 GHz large-grain Nb CEBAF upgrade low-loss shape cavity.

  11. Half-Wave, beta=0.43 Cavity Prototyping for a Heavy Ion Linac

    SciTech Connect (OSTI)

    Popielarski, John; Compton, Chris C.; Hartung, Walter; Johnson, Mat; Oliva, John; York, R. C.; Marti, Felix

    2008-04-01

    A medium velocity half wave resonator has been designed and prototyped at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU) for use in a heavy ion linac. The cavity is designed to provide 3.7 MV of accelerating voltage at an optimum beta = v/c = 0.53, with peak surface electric and magnetic fields of 32.5 MV/m and 79 mT, respectively. The cavity was designed for stiffness and tunability, as well as straightforward fabrication, assembly and cleaning. Measurements were performed to confirm Finite Element Analysis (FEA) predictions for modal analysis, bath pressure sensitivity, tuner stiffness and tuning range. A copper cavity prototype has been fabricated to confirm tolerances and formability. A tuner prototype has been built. The helium vessel and power coupler have been designed.

  12. High Efficiency Organic Solar Cells: December 16, 2009 - February 2, 2011

    SciTech Connect (OSTI)

    Walker, K.; Joslin, S.

    2011-05-01

    Details on the development of novel organic solar cells incorporating Trimetasphere based acceptors are presented including: baseline performance for Lu-PCBEH acceptor blended with P3HT demonstrated at 4.89% PCE exceeding the 4.5% PCE goal; an increase of over 250mV in Voc was demonstrated for Lu-PCBEH blended with low band gap polymers compared to a comparable C60-PCBM device. The actual Voc was certified at 260mV higher for a low band gap polymer device using the Lu-PCBEH acceptor; and the majority of the effort was focused on development of a device with over 7% PCE. While low current and fill factors suppressed overall device performance for the low band gap polymers tested, significant discoveries were made that point the way for future development of these novel acceptor materials.

  13. The effects of ionophores and metabolic inhibitors on methanogenesis and energy-related properties of Methanobacterium bryantii

    SciTech Connect (OSTI)

    Jarrell, K.F.; Sprott, G.D.

    1983-08-01

    The effects of numerous ionophores and inhibitors were tested on methane synthesis, intracellular ATP and potassium concentrations, and the proton motive force of the methanogenic archaebacterium Methanobacterium bryantii. M. bryantii had an internal pH near 6.8 (and hence little delta pH during growth) with an electrical potential of --127 mV in growth medium and --105 mV in a pH 6.5 buffer. The study has identified agents which, in M. bryantii, can effectively cause a decline of intracellular ATP (gramicidin, acetylene) and potassium concentrations (gramicidin, nigericin), inhibit methane synthesis (acetylene, gramicidin, nigericin, triphenylmethylphosphonium bromide), eliminate the electrical potential (high extracellular potassium ion concentrations), and dissipate artificially imposed, inside alkaline, pH gradients (monensin, nigericin, carbonyl cyanide m-chlorophenylhydrazone). Carbonyl cyanide m-chlorophenylhydrazone was generally ineffective in media or buffers reduced with cysteine-sulfide but could be effective in cysteine-free solutions reduced with hydrogen sulfide.

  14. Two-klystron Binary Pulse Compression at SLAC

    SciTech Connect (OSTI)

    Farkas, Z.D.; Lavine, T.L.; Menegat, A.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B.

    1993-04-01

    The Binary Pulse Compression system installed at SLAC was tested using two klystrons, one with 10 MW and the other with 34 MW output. By compressing 560 ns klystron pulses into 70 ns, the measured BPC output was 175 MW, limited by the available power from the two klystrons. This output was used to provide 100-MW input to a 30-cell X-band structure in which a 100-MV/m gradient was obtained. This system, using the higher klystron outputs expected in the future has the potential to deliver the 350 MW needed to obtain 100 MV/m gradients in the 1.8-m NLC prototype structure. This note describes the timing, triggering, and phase coding used in the two-klystron experiment, and the expected and measured net-work response to three- or two-stage modulation.

  15. Emittance Studies of the BNL/SLAC/UCLA 1.6 Cell Photocathode RF Gun

    SciTech Connect (OSTI)

    Palmer, D.T.; Wang, X.J.; Miller, R.H.; Babzien, M.; Ben-Zvi, I.; Pellegrini, C.; Sheehan, J.; Skaritka, J.; Winick, H.; Woodle, M.; Yakimenko, V.; /Brookhaven

    2011-09-09

    The symmetrized 1.6 cell S-band photocathode gun developed by the BNL/SLAC/UCLA collaboration is in operation at the Brookhaven Accelerator Test Facility (ATF). A novel emittance compensation solenoid magnet has also been designed, built and is in operation at the ATF. These two subsystems form an emittance compensated photoinjector used for beam dynamics, advanced acceleration and free electron laser experiments at the ATF. The highest acceleration field achieved on the copper cathode is 150 MV/m, and the guns normal operating field is 130 MV/m. The maximum rf pulse length is 3 {mu}s. The transverse emittance of the photoelectron beam were measured for various injection parameters. The 1 nC emittance results are presented along with electron bunch length measurements that indicated that at above the 400 pC, space charge bunch lengthening is occurring. The thermal emittance, {epsilon}{sub o}, of the copper cathode has been measured.

  16. Multivariate analysis of remote LIBS spectra using partial least squares, principal component analysis, and related techniques

    SciTech Connect (OSTI)

    Clegg, Samuel M; Barefield, James E; Wiens, Roger C; Sklute, Elizabeth; Dyare, Melinda D

    2008-01-01

    Quantitative analysis with LIBS traditionally employs calibration curves that are complicated by the chemical matrix effects. These chemical matrix effects influence the LIBS plasma and the ratio of elemental composition to elemental emission line intensity. Consequently, LIBS calibration typically requires a priori knowledge of the unknown, in order for a series of calibration standards similar to the unknown to be employed. In this paper, three new Multivariate Analysis (MV A) techniques are employed to analyze the LIBS spectra of 18 disparate igneous and highly-metamorphosed rock samples. Partial Least Squares (PLS) analysis is used to generate a calibration model from which unknown samples can be analyzed. Principal Components Analysis (PCA) and Soft Independent Modeling of Class Analogy (SIMCA) are employed to generate a model and predict the rock type of the samples. These MV A techniques appear to exploit the matrix effects associated with the chemistries of these 18 samples.

  17. Real-Time Target Position Estimation Using Stereoscopic Kilovoltage/Megavoltage Imaging and External Respiratory Monitoring for Dynamic Multileaf Collimator Tracking

    SciTech Connect (OSTI)

    Cho, Byungchul; Poulsen, Per Rugaard; Sawant, Amit; Ruan, Dan; Keall, Paul J.

    2011-01-01

    Purpose: To develop a real-time target position estimation method using stereoscopic kilovoltage (kV)/megavoltage (MV) imaging and external respiratory monitoring, and to investigate the performance of a dynamic multileaf collimator tracking system using this method. Methods and Materials: The real-time three-dimensional internal target position estimation was established by creating a time-varying correlation model that connected the external respiratory signals with the internal target motion measured intermittently using kV/MV imaging. The method was integrated into a dynamic multileaf collimator tracking system. Tracking experiments were performed for 10 thoracic/abdominal traces. A three-dimensional motion platform carrying a gold marker and a separate one-dimensional motion platform were used to reproduce the target and external respiratory motion, respectively. The target positions were detected by kV (1 Hz) and MV (5.2 Hz) imaging, and external respiratory motion was captured by an optical system (30 Hz). The beam-target alignment error was quantified as the positional difference between the target and circular beam center on the MV images acquired during tracking. The correlation model error was quantified by comparing a model estimate and measured target positions. Results: The root-mean-square errors in the beam-target alignment that had ranged from 3.1 to 7.6 mm without tracking were reduced to <1.5 mm with tracking, except during the model building period (6 s). The root-mean-square error in the correlation model was submillimeters in all directions. Conclusion: A novel real-time target position estimation method was developed and integrated into a dynamic multileaf collimator tracking system and demonstrated an average submillimeter geometric accuracy after initializing the internal/external correlation model. The method used hardware tools available on linear accelerators and therefore shows promise for clinical implementation.

  18. A simple method to quantify the coincidence between portal image graticules and radiation field centers or radiation isocenter

    SciTech Connect (OSTI)

    Du Weiliang; Yang, James; Luo Dershan; Martel, Mary

    2010-05-15

    Purpose: The aim of this study was to develop a computerized method to quantify the coincidence between portal image graticules and radiation field centers or radiation isocenter. Three types of graticules were included in this study: Megavoltage (MV) mechanical graticule, MV electronic portal imaging device digital graticule, and kilovoltage (kV) on-board imaging digital graticule. Methods: A metal ball bearing (BB) was imaged with MV and kV x-ray beams in a procedure similar to a Winston-Lutz test. The radiation fields, graticules, and BB were localized in eight portal images using Hough transform-based computer algorithms. The center of the BB served as a static reference point in the 3D space so that the distances between the graticule centers and the radiation field centers were calculated. The radiation isocenter was determined from the radiation field centers at different gantry angles. Results: Misalignments of MV and kV portal imaging graticules varied with the gantry or x-ray source angle as a result of mechanical imperfections of the linear accelerator and its imaging system. While the three graticules in this study were aligned to the radiation field centers and the radiation isocenter within 2.0 mm, misalignments of 1.5-2.0 mm were found at certain gantry angles. These misalignments were highly reproducible with the gantry rotation. Conclusions: A simple method was developed to quantify the alignments of portal image graticules directly against the radiation field centers or the radiation isocenter. The advantage of this method is that it does not require the BB to be placed exactly at the radiation isocenter through a precalibrated surrogating device such as room lasers or light field crosshairs. The present method is useful for radiation therapy modalities that require high-precision portal imaging such as image-guided stereotactic radiotherapy.

  19. Oxidative dehydrogenation of alkanes to unsaturated hydrocarbons

    DOE Patents [OSTI]

    Kung, Harold H. (Wilmette, IL); Chaar, Mohamed A. (Homs, SY)

    1988-01-01

    Oxidative dehydrogenation of alkanes to unsaturated hydrocarbons is carried out over metal vanadate catalysts under oxidizing conditions. The vanadate catalysts are represented by the formulas M.sub.3 (VO.sub.4).sub.2 and MV.sub.2 O.sub.6, M representing Mg, Zn, Ca, Pb, or Cd. The reaction is carried out in the presence of oxygen, but the formation of oxygenate by-products is suppressed.

  20. News Item

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Efficient silicon solar cells with dopant-free asymmetric heterocontacts Light JV characteristic and schematic of the dopant-free asymmetric heterocontact (DASH) silicon solar cell showing a conversion efficiency of 19.4%, with a high Voc above 710 mV, has been achieved at the proof-of-concept stage. TCO refers to a Transparent Conductive Oxide stack. Scientific Achievement Demonstration of efficient crystalline silicon solar cells by Molecular Foundry users and staff without the use of

  1. Nuclear Science/Nuclear Chemistry

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    nuclear science nuclear chemistry Nuclear Science/Nuclear Chemistry Nuclear Physics The 10-MV tandem accelerator at CAMS provides a platform for conducting nuclear physics experiment both for basic science and lab mission-related programs. For example, we performed a new cross section measurement of the astrophysically important reaction 40Ca(a,g)44Ti in which high purity CaO targets were irradiated with helium ions at several different discrete energies. The reaction rate was measured on-line

  2. Electromagnetic squeezer for compressing squeezable electron tunneling junctions. Technical report

    SciTech Connect (OSTI)

    Moreland, J.; Hansma, P.K.

    1984-01-01

    The resistance of squeezable electron tunnel junctions (SET junctions) can be adjusted with an electromagnetic squeezer. For junctions immersed in liquid helium, the resistance is stable to approximately 0.1%. This stability is sufficient for measurements of superconducting energy gaps and for superconducting phonon spectroscopy out to 50 mV applied bias. Increased stability, especially at higher biases, will be necessary for inelastic electron tunneling spectroscopy.

  3. Electromagnetic squeezer for compressing squeezable electron tunnelling junctions

    SciTech Connect (OSTI)

    Moreland, J.; Hansma, P.K.

    1984-03-01

    The resistance of squeezable electron tunnel junctions (SET junctions) can be adjusted with an electromagnetic squeezer. For junctions immersed in liquid helium, the resistance is stable to approximately 0.1%. This stability is sufficient for measurements of superconducting energy gaps and for superconducting phonon spectroscopy out to 50-mV applied bias. Increased stability, especially at higher biases, will be necessary for inelastic electron tunnelling spectroscopy.

  4. SU-E-J-52: Decreasing Frequency of Performing TG-142 Imaging QA – 5 Year Experience

    SciTech Connect (OSTI)

    Lin, T; Ma, C

    2015-06-15

    Purpose This study is an update to check if the frequency of imaging QA suggested by AAPM Task Group Report 142 (TG142) is necessary with our 5 year experience. TG142 presents recommendations for QA criteria of IGRT treatment. ACR has adopted it to be the requirements for any radiatiotherapy practices; however, we propose to reduce the frequency on image quality QA according to this 5 year study.Method and Materials: This study uses VarianIX2100 and Siemens Artiste Linacs to perform QAs on KV, MV, CBCT modalities. The QA was designed following under the recommendations of TG142. This study reports the daily imaging positioning/repositioning and imaging and treatment coordinate coincidence. QA results on kV, MV and CBCT from 4/7/2010∼3/11/15 are analyzed. KV, MV, CBCT images are taken with the Varian isocube localized at the isocenter. Digital graticule is used in the software to verify the isocenter position. CBCT images are taken with the cube placed at 1cm superior, lateral and anterior of the isocenter. In-line fusion software is used to verify the contrived shift. Digital ruler provided at the on-board-imaging software or adaptive-targeting software was used to measure the position differences. The position differences were recorded at AP,LR,SI directions. Results 5 year records on kV, MV, CBCT show the shifts in all three directions are within the tolerance of 1mm suggested in TG142 for stereotactic radiation treatment(SRS/SRT). There is no occasion where shifts are outside 1mm tolerance. Conclusions The daily imaging QA suggested in TG142 is useful in ensuring the accuracy needed for SRS/SRT in IGRT. 5 year measurements presented suggest that decreasing the frequency of imaging QA may be acceptable, in particular for institutions reporting no violation of tolerance over periods of few years.

  5. EMGeo IXPUG 2016

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tareq Malas, Thorsten Kurth, Jack Deslippe Optimizing SpMV and IDR Krylov solver in EMGeo for Intel KNL IXPUG 2016 Frankfurt, Germany June 23, 2016 * Geophysical tomography: measure composition of the ground by scattering seismic waves (inverse scattering problem) 2 EMGeo - Introduction Petrov and Newman 2014 * Geophysical tomography: measure composition of the ground by scattering seismic waves (inverse scattering problem) * Finite-Difference approximation of propagation kernel on grid with N=N

  6. Cryogenic test of double quarter wave crab cavity for the LHC High luminosity upgrade

    SciTech Connect (OSTI)

    Xiao, B.; Alberty, L.; Belomestnykh, S.; Ben-Zvi, I.; Calaga, R.; Cullen, C.; Capatina, O.; Hammons, L.; Li, Z.; Marques, C.; Skaritka, J.; Verdu-Andres, S.; Wu, Q.

    2015-05-03

    A Proof-of-Principle (PoP) Double Quarter Wave Crab Cavity (DQWCC) was designed and fabricated for the Large Hadron Collider (LHC) luminosity upgrade. A vertical cryogenic test has been done at Brookhaven National Lab (BNL). The cavity achieved 4.5 MV deflecting voltage with a quality factor above 3×109. We report the test results of this design.

  7. Oxidative dehydrogenation of alkanes to unsaturated hydrocarbons

    DOE Patents [OSTI]

    Kung, H.H.; Chaar, M.A.

    1988-10-11

    Oxidative dehydrogenation of alkanes to unsaturated hydrocarbons is carried out over metal vanadate catalysts under oxidizing conditions. The vanadate catalysts are represented by the formulas M[sub 3](VO[sub 4])[sub 2] and MV[sub 2]O[sub 6], M representing Mg, Zn, Ca, Pb, or Cd. The reaction is carried out in the presence of oxygen, but the formation of oxygenate by-products is suppressed.

  8. 2012 Groundwater Monitoring Report Central Nevada Test Area, Subsurface Corrective Action Unit 443

    SciTech Connect (OSTI)

    2013-04-01

    The Central Nevada Test Area was the site of a 0.2- to 1-megaton underground nuclear test in 1968. The surface of the site has been closed, but the subsurface is still in the corrective action process. The corrective action alternative selected for the site was monitoring with institutional controls. Annual sampling and hydraulic head monitoring are conducted as part of the subsurface corrective action strategy. The site is currently in the fourth year of the 5-year proof-of-concept period that is intended to validate the compliance boundary. Analytical results from the 2012 monitoring are consistent with those of previous years. Tritium remains at levels below the laboratory minimum detectable concentration in all wells in the monitoring network. Samples collected from reentry well UC-1-P-2SR, which is not in the monitoring network but was sampled as part of supplemental activities conducted during the 2012 monitoring, indicate concentrations of tritium that are consistent with previous sampling results. This well was drilled into the chimney shortly after the detonation, and water levels continue to rise, demonstrating the very low permeability of the volcanic rocks. Water level data from new wells MV-4 and MV-5 and recompleted well HTH-1RC indicate that hydraulic heads are still recovering from installation and testing. Data from wells MV-4 and MV-5 also indicate that head levels have not yet recovered from the 2011 sampling event during which several thousand gallons of water were purged. It has been recommended that a low-flow sampling method be adopted for these wells to allow head levels to recover to steady-state conditions. Despite the lack of steady-state groundwater conditions, hydraulic head data collected from alluvial wells installed in 2009 continue to support the conceptual model that the southeast-bounding graben fault acts as a barrier to groundwater flow at the site.

  9. Poster — Thur Eve — 18: Cherenkov Emission By High-Energy Radiation Therapy Beams: A Characterization Study

    SciTech Connect (OSTI)

    Zlateva, Y.; El Naqa, I.; Quitoriano, N.

    2014-08-15

    We investigate Cherenkov emission (CE) by radiotherapy beams via radiation dose-versus-CE correlation analyses, CE detection optimization by means of a spectral shift towards the near-infrared (NIR) window of biological tissue, and comparison of CE to on-board MV imaging. Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissue-simulating phantom composed of water, Intralipid®, and beef blood; plastic phantom with solid water insert. The detector system comprises an optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated CCD. The NIR shift was carried out with CdSe/ZnS quantum dots (QDs), emitting at (650±10) nm. CE and MV images were acquired with a CMOS camera and electronic portal imaging device. MC and experimental studies indicate a strong linear dose-CE correlation (Pearson coefficient > 0.99). CE by an 18-MeV beam was effectively NIR-shifted in water and a tissue-simulating phantom, exhibiting a significant increase at 650 nm for QD depths up to 10 mm. CE images exhibited relative contrast superior to MV images by a factor of 30. Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing and QDs can be used to improve CE detectability, potentially yielding image quality superior to MV imaging for the case of low-density-variability, low-optical-attenuation materials (ex: breast/oropharynx). Ongoing work involves microenvironment functionalization of QDs and application of multi-channel spectrometry for simultaneous acquisition of dosimetric and tumor oxygenation signals.

  10. High gradient rf gun studies of CsBr photocathodes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10⁻⁹ torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  11. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Relative Content of Black Carbon in Submicron Aerosol as a Sign of the Effect of Forest Fire Smokes V.S. Kozlov, M.V. Panchenko, and E.P. Yausheva Institute of Atmospheric Optics Tomsk, Russia Introduction Biomass burning occurs often in regions containing vast forest tracts and peat-bogs. These processes are accompanied by the emission of aerosol particles and crystal carbon (black carbon [BC], soot). BC is the predominant source of solar absorption in atmospheric aerosol, which impacts

  12. Evaluation of Sulfur Spinel Compounds for Multivalent Battery Cathode

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Applications - Joint Center for Energy Storage Research August 17, 2016, Research Highlights Evaluation of Sulfur Spinel Compounds for Multivalent Battery Cathode Applications A group of 3d transition-metal sulfur-spinel compounds were systematically assessed for MV cathode applications, based on their electrochemical and thermodynamic properties . Cr2S4, Ti2S4 and Mn2S4 spinel compounds exhibit superior Mg2+ mobility, and hence, emerge as the top three candidates. Scientific Achievement

  13. Microsoft Word - DOE-ID-11-011 Michigan EC.doc

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1 SECTION A. Project Title: Acquisition of a 3 MV Tandem Accelerator for Research and Teaching in Nuclear Science and Engineering - University of Michigan SECTION B. Project Description The goal of this project is to provide upgraded, robust and long-term capability to conduct radiation damage studies, ion beam analysis of materials and processing of materials using ion beams, in support of the research and teaching mission in nuclear science and engineering at the University of Michigan. The

  14. High gradient rf gun studies of CsBr photocathodes

    SciTech Connect (OSTI)

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 210?? torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  15. Triangle Universities Nuclear Laboratory : 2011

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    at LENA| Reaction Rates| UNC Astrophysics| Laboratory for Experimental Nuclear Astrophysics (LENA) The LENA is among only a few accelerator facilities in the world dedicated entirely to nuclear astrophysics experiments. It has two low-energy electrostatic accelerators that are capable of delivering high-current charged-particle beams to a common target. One is an ECR source on a 200-kV platform and the other one is a 1-MV JN Van de Graaff accelerator. Both accelerators are fully

  16. Poster Thur Eve 62: A Retrospective Assessment of the Prevalence and Dosimetric Effect of Lateral Electron Disequilibrium in a Population of Lung Cancer Patients Treated by Stereotactic Body Radiation Therapy

    SciTech Connect (OSTI)

    Disher, Brandon; Wade, Laura; Hajdok, George; Gaede, Stewart; Battista, Jerry J.; Palma, David

    2014-08-15

    Stereotactic Body Radiation Therapy (SBRT) is a treatment option for early stage non-small cell lung cancer (NSCLC). SBRT uses tightly conformed megavoltage (MV) x-ray beams to ablate the tumour. However, small MV x-ray fields may produce lateral electron disequilibrium (LED) within lung tissue, which can reduce the dose to tumour. The goal of this work is to estimate the prevalence of LED in NSCLC patients treated with SBRT, and determine dose effects for patients prone or averse to LED. Thirty NSCLC patients were randomly selected for analysis. 4-dimensional CT lung images were segmented into the right and left upper and lower lobes (RUL, RLL, LUL, LLL), and the right middle lobe. Dose calculations were performed using volume-modulated arc therapy in the Pinnacle{sup 3} TPS. Most tumours were located in the upper lobes (RUL 53%, LUL 27%) where density was significantly lower (RUL ?80846 HU vs. RLL ?74371 HU; LUL ?808 56 HU vs. LLL ?74670 HU; p<0.001). In general, the prevalence of LED increased with higher beam energy. Using 6MV photons, patients with a RUL tumour experienced moderate (81 %), and mild (19%) levels of LED. At 18MV, LED became more prominent with severe (50%) and moderate (50%) LED exhibited. Dosimetrically, for patients prone to LED, poorer target coverage (i.e. increased R100 by 20%) and improved lung sparing (i.e. reduced V20 by ?46%) was observed. The common location of lung cancers in the upper lobes, coupled with lower lung density, results in the potential occurrence of LED, which may underdose the tumour.

  17. Large scale two-dimensional arrays of magnesium diboride superconducting quantum interference devices

    SciTech Connect (OSTI)

    Cybart, Shane A. Dynes, R. C.; Wong, T. J.; Cho, E. Y.; Beeman, J. W.; Yung, C. S.; Moeckly, B. H.

    2014-05-05

    Magnetic field sensors based on two-dimensional arrays of superconducting quantum interference devices were constructed from magnesium diboride thin films. Each array contained over 30?000 Josephson junctions fabricated by ion damage of 30?nm weak links through an implant mask defined by nano-lithography. Current-biased devices exhibited very large voltage modulation as a function of magnetic field, with amplitudes as high as 8?mV.

  18. Section 60

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Aerosol Extinction of 0.44 to 12 M Radiation by Atmospheric Hazes (Continent, Coastal and Arid Zones) Yu.A. Pkhalagov, M.V. Panchenko, V.N. Uzhegov, and N.N. Shchelkanov Institute of Atmospheric Optics, Tomsk, Russia The atmospheric haze is known to enhance the earth's albedo, characterization of meteorological conditions at the time of and this must be accounted for in radiation calculations. Since measurements being discussed is given in Table 1, listing the the optical properties of

  19. Relativistic klystron research at SLAC and LLNL

    SciTech Connect (OSTI)

    Allen, M.A.; Callin, R.S.; Deruyter, H.; Eppley, K.R.; Fowkes, W.R.; Herrmannsfeldt, W.B.; Higo, T.; Hoag, H.A.; Lavine, T.L.; Lee, T.G.; Loew, G.A.; Miller, R.H.; Morton, P.L.; Palmer, R.B.; Paterson, J.M.; Ruth, R.D.; Schwarz, H.D.; Takeuchi, Y.; Vlieks, A.E.; Wang, J.W.; Wilson, P.B.; Hopkins, D.B.; Sessler, A.M.; Barletta, W.A.; Birx, D.L.; Boyd, J.K.; Houck, T.; Westenskow, G.A.; Yu, S.S.

    1988-06-01

    We are developing relativistic klystrons as a power source for high gradient accelerator applications such as large linear electron-positron colliders and compact accelerators. We have attained 200 MW peak power at 11.4 GHz from a relativistic klystron, and 140 MV/m longitudinal gradient in a short 11.4 GHz accelerator section. We report here briefly on our experiments so far. 5 refs., 1 fig., 1 tab.

  20. Automatic bench for study and selection of single-electron photomultipliers

    SciTech Connect (OSTI)

    Venikov, A.A.; Shelevoi, K.D.

    1985-12-01

    This paper describes apparatus based on the Elektronika-60 computer that selects single-electron photomultipliers that are most suitable for lidar studies of the atmosphere and, having determined their amplitude distribution, establishes optimum discrimination thresholds for differential and integral amplitudes discriminators. The photmultiplier-supply range is 1.0-3.0 kV and the range of discrimination levels is 0-10 mV. The circuit of the original differential pulse discriminatorcounter used in the bench is given.

  1. SU-E-T-238: Monte Carlo Estimation of Cerenkov Dose for Photo-Dynamic Radiotherapy

    SciTech Connect (OSTI)

    Chibani, O; Price, R; Ma, C; Eldib, A; Mora, G

    2014-06-01

    Purpose: Estimation of Cerenkov dose from high-energy megavoltage photon and electron beams in tissue and its impact on the radiosensitization using Protoporphyrine IX (PpIX) for tumor targeting enhancement in radiotherapy. Methods: The GEPTS Monte Carlo code is used to generate dose distributions from 18MV Varian photon beam and generic high-energy (45-MV) photon and (45-MeV) electron beams in a voxel-based tissueequivalent phantom. In addition to calculating the ionization dose, the code scores Cerenkov energy released in the wavelength range 375425 nm corresponding to the pick of the PpIX absorption spectrum (Fig. 1) using the Frank-Tamm formula. Results: The simulations shows that the produced Cerenkov dose suitable for activating PpIX is 4000 to 5500 times lower than the overall radiation dose for all considered beams (18MV, 45 MV and 45 MeV). These results were contradictory to the recent experimental studies by Axelsson et al. (Med. Phys. 38 (2011) p 4127), where Cerenkov dose was reported to be only two orders of magnitude lower than the radiation dose. Note that our simulation results can be corroborated by a simple model where the Frank and Tamm formula is applied for electrons with 2 MeV/cm stopping power generating Cerenkov photons in the 375425 nm range and assuming these photons have less than 1mm penetration in tissue. Conclusion: The Cerenkov dose generated by high-energy photon and electron beams may produce minimal clinical effect in comparison with the photon fluence (or dose) commonly used for photo-dynamic therapy. At the present time, it is unclear whether Cerenkov radiation is a significant contributor to the recently observed tumor regression for patients receiving radiotherapy and PpIX versus patients receiving radiotherapy only. The ongoing study will include animal experimentation and investigation of dose rate effects on PpIX response.

  2. Fission Spectrum

    DOE R&D Accomplishments [OSTI]

    Bloch, F.; Staub, H.

    1943-08-18

    Measurements of the spectrum of the fission neutrons of 25 are described, in which the energy of the neutrons is determined from the ionization produced by individual hydrogen recoils. The slow neutrons producing fission are obtained by slowing down the fast neutrons from the Be-D reaction of the Stanford cyclotron. In order to distinguish between fission neutrons and the remaining fast cyclotron neutrons both the cyclotron current and the pusle amplifier are modulated. A hollow neutron container, in which slow neutrons have a lifetime of about 2 milliseconds, avoids the use of large distances. This method results in much higher intensities than the usual modulation arrangement. The results show a continuous distribution of neutrons with a rather wide maximum at about 0.8 MV falling off to half of its maximum value at 2.0 MV. The total number of netrons is determined by comparison with the number of fission fragments. The result seems to indicate that only about 30% of the neutrons have energies below .8 MV. Various tests are described which were performed in order to rule out modification of the spectrum by inelastic scattering. Decl. May 4, 1951

  3. Coaxial Coupling Scheme for TESLA/ILC-type Cavities

    SciTech Connect (OSTI)

    J.K. Sekutowicz, P. Kneisel

    2010-05-01

    This paper reports about our efforts to develop a flangeable coaxial coupler for both HOM and fundamental coupling for 9-cell TESLA/ILC-type cavities. The cavities were designed in early 90‘s for pulsed operation with a low duty factor, less than 1 %. The proposed design of the coupler has been done in a way, that the magnetic flux B at the flange connection is minimized and only a field of <5 mT would be present at the accelerating field Eacc of ~ 36 MV/m (B =150 mT in the cavity). Even though we achieved reasonably high Q-values at low field, the cavity/coupler combination was limited in the cw mode to only ~ 7 MV/m, where a thermally initiated degradation occurred. We have improved the cooling conditions by initially drilling radial channels every 30 degrees, then every 15 degrees into the shorting plate. The modified prototype performed well up to 9 MV/m in cw mode. This paper reports about our experiences with the further modified coaxial coupler and about test results in cw and low duty cycle pulsed mode, similar to the TESLA/ILC operation conditions.

  4. March 2011 Groundwater Sampling at the Project Shoal Site (Data Validation Package)

    SciTech Connect (OSTI)

    2011-07-01

    The U.S. Department of Energy Office of Legacy Management conducted annual sampling at the Project Shoal Area (Shoal) in March 2011. Wells HC-1, HC-2, HC-4, HC-5, HC-6, HC-7, MV-1, MV-2 and MV-3 were sampled as specified in the Sampling and Analysis Plan for U.S. Department of Energy Office of Legacy Management Sites (LMS/PLN/S04351, continually updated). Two extra tritium samples were collected from well HC-4, one sample (HC-4-400) was collected at about 1/3 of the purge volume (135 gallons), the second sample (HC-4-400) was collected at 2/3 of purge volume (270 gallons). These additional samples were collected prior to completing the well purging process to evaluate the effects well purging has on the analytical results. Samples were not collected from locations HC-3 and HC-8 at the direction of the S.M. Stoller Corporation site lead.

  5. Results of two LANL [beta]=0.175, 350-MHZ, 2-GAP spoke cavities

    SciTech Connect (OSTI)

    Tajima, T.; Edwards, R. L.; Gentzlinger, R.C.; Krawczyk, F. L.; Ledford, J. E.; Liu, Jianfei; Montoya, D. I.; Roybal, R. J.; Schrage, D. L.; Shapiro, A. H.; Barni, D.; Bosotti, A.; Pagani, C. D.

    2003-01-01

    Two {beta} = 0.175, 350 MHz, 2-gap superconducting (SC) spoke cavities were fabricated in industry under the Advanced Accelerator Applications (AAA) project for the transmutation of nuclear waste. These cavities are promising candidates for the accelerating structures between a RFQ and the elliptical SC cavities for proton and heavy ion linacs. Since their delivery in July 2002, they have been tested in terms of mechanical properties, low-temperature performance, i.e., Qo-Eaccc urves at 4 K and 2 K, surface resistance dependence on temperature and for multipacting (MP). The two cavities achieved accelerating fields of 13.5 MV/m and 13.0 MV/m as compared to the required field of 7.5 MV/m with enough margin for the quality factor. These cavities seem to need more time to condition away MP than elliptical cavities, but MP does not occur once the cavity is conditioned and kept at 4 K. The length of the 103 mm-diameter nominal coupler port was found to be too short for the penetrating field.

  6. Low Wind Speed Turbine Project Phase II: The Application of Medium-Voltage Electrical Apparatus to the Class of Variable Speed Multi-Megawatt Low Wind Speed Turbines; 15 June 2004--30 April 2005

    SciTech Connect (OSTI)

    Erdman, W.; Behnke, M.

    2005-11-01

    Kilowatt ratings of modern wind turbines have progressed rapidly from 50 kW to 1,800 kW over the past 25 years, with 3.0- to 7.5-MW turbines expected in the next 5 years. The premise of this study is simple: The rapid growth of wind turbine power ratings and the corresponding growth in turbine electrical generation systems and associated controls are quickly making low-voltage (LV) electrical design approaches cost-ineffective. This report provides design detail and compares the cost of energy (COE) between commercial LV-class wind power machines and emerging medium-voltage (MV)-class multi-megawatt wind technology. The key finding is that a 2.5% reduction in the COE can be achieved by moving from LV to MV systems. This is a conservative estimate, with a 3% to 3.5% reduction believed to be attainable once purchase orders to support a 250-turbine/year production level are placed. This evaluation considers capital costs as well as installation, maintenance, and training requirements for wind turbine maintenance personnel. Subsystems investigated include the generator, pendant cables, variable-speed converter, and padmount transformer with switchgear. Both current-source and voltage-source converter/inverter MV topologies are compared against their low-voltage, voltage-source counterparts at the 3.0-, 5.0-, and 7.5-MW levels.

  7. Low power zinc-oxide based charge trapping memory with embedded silicon nanoparticles via poole-frenkel hole emission

    SciTech Connect (OSTI)

    El-Atab, Nazek; Nayfeh, Ammar; Ozcan, Ayse; Alkis, Sabri; Okyay, Ali K.; Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara

    2014-01-06

    A low power zinc-oxide (ZnO) charge trapping memory with embedded silicon (Si) nanoparticles is demonstrated. The charge trapping layer is formed by spin coating 2?nm silicon nanoparticles between Atomic Layer Deposited ZnO steps. The threshold voltage shift (?V{sub t}) vs. programming voltage is studied with and without the silicon nanoparticles. Applying ?1?V for 5?s at the gate of the memory with nanoparticles results in a ?V{sub t} of 3.4?V, and the memory window can be up to 8?V with an excellent retention characteristic (>10 yr). Without nanoparticles, at ?1?V programming voltage, the ?V{sub t} is negligible. In order to get ?V{sub t} of 3.4?V without nanoparticles, programming voltage in excess of 10?V is required. The negative voltage on the gate programs the memory indicating that holes are being trapped in the charge trapping layer. In addition, at 1?V the electric field across the 3.6?nm tunnel oxide is calculated to be 0.36 MV/cm, which is too small for significant tunneling. Moreover, the ?V{sub t} vs. electric field across the tunnel oxide shows square root dependence at low fields (E?MV/cm) and a square dependence at higher fields (E?>?2.7 MV/cm). This indicates that Poole-Frenkel Effect is the main mechanism for holes emission at low fields and Phonon Assisted Tunneling at higher fields.

  8. Cobalt-60 tomotherapy: Clinical treatment planning and phantom dose delivery studies

    SciTech Connect (OSTI)

    Dhanesar, Sandeep; Darko, Johnson; Joshi, Chandra P.; Kerr, Andrew; John Schreiner, L.

    2013-08-15

    Purpose: Investigations have shown that a Cobalt-60 (Co-60) radioactive source has the potential to play a role in intensity modulated radiation therapy (IMRT). In this paper, Co-60 tomotherapy's conformal dose delivery potential is evaluated by delivering conformal dose plans on a cylindrical homogeneous phantom containing clinical structures similar to those found in a typical head and neck (H and N) cancer. Also, the clinical potential of Co-60 tomotherapy is investigated by generating 2D clinical treatment plans for H and N and prostate anatomical regions. These plans are compared with the 6 MV based treatment plans for modalities such as linear accelerator-based tomotherapy and broad beam IMRT, and 15 MV based 3D conformal radiation therapy (3DCRT).Methods: For experimental validation studies, clinical and nonclinical conformal dose patterns were delivered on circular, homogeneous phantoms containing GafChromic film. For clinical planning study, dose calculations were performed with the EGSnrc Monte Carlo program, where a Theratronics 780C Co-60 unit and a 6 MV linear accelerator were modeled with a MIMiC binary multileaf collimator. An inhouse inverse treatment planning system was used to optimize tomotherapy plans using the same optimization parameters for both Co-60 and 6 MV beams. The IMRT and 3DCRT plans for the clinical cases were generated entirely in the Eclipse treatment planning system based on inhouse IMRT and 3DCRT site specific protocols.Results: The doses delivered to the homogeneous phantoms agreed with the calculations, indicating that it is possible to deliver highly conformal doses with the Co-60 unit. The dose distributions for Co-60 tomotherapy clinical plans for both clinical cases were similar to those obtained with 6 MV based tomotherapy and IMRT, and much more conformal compared to 3DCRT plans. The dose area histograms showed that the Co-60 plans achieve the dose objectives for the targets and organs at risk.Conclusions: These results

  9. TU-C-BRE-02: A Novel, Highly Efficient and Automated Quality Assurance Tool for Modern Linear Accelerators

    SciTech Connect (OSTI)

    Goddu, S; Sun, B; Yaddanapudi, S; Kamal, G; Mutic, S; Baltes, C; Rose, S; Stinson, K

    2014-06-15

    Purpose: Quality assurance (QA) of complex linear accelerators is critical and highly time consuming. Varians Machine Performance Check (MPC) uses IsoCal phantom to test geometric and dosimetric aspects of the TrueBeam systems in <5min. In this study we independently tested the accuracy and robustness of the MPC tools. Methods: MPC is automated for simultaneous image-acquisition, using kV-and-MV onboard-imagers (EPIDs), while delivering kV-and-MV beams in a set routine of varying gantry, collimator and couch angles. MPC software-tools analyze the images to test: i) beam-output and uniformity, ii) positional accuracy of isocenter, EPIDs, collimating jaws (CJs), MLC leaves and couch and iii) rotational accuracy of gantry, collimator and couch. 6MV-beam dose-output and uniformity were tested using ionization-chamber (IC) and ICarray. Winston-Lutz-Tests (WLT) were performed to measure isocenter-offsets caused by gantry, collimator and couch rotations. Positional accuracy of EPIDs was evaluated using radio-opaque markers of the IsoCal phantom. Furthermore, to test the robustness of the MPC tools we purposefully miscalibrated a non-clinical TrueBeam by introducing errors in beam-output, energy, symmetry, gantry angle, couch translations, CJs and MLC leaves positions. Results: 6MV-output and uniformity were within 0.6% for most measurements with a maximum deviation of 1.0%. Average isocenter-offset caused by gantry and collimator rotations was 0.3160.011mm agreeing with IsoLock (0.274mm) and WLT (0.41mm). Average rotation-induced couch-shift from MPC was 0.3780.032mm agreeing with WLT (0.35mm). MV-and-kV imager-offsets measured by MPC were within 0.15mm. MPC predicted all machine miscalibrations within acceptable clinical tolerance. MPC detected the output miscalibrations within 0.61% while the MLC and couch positions were within 0.06mm and 0.14mm, respectively. Gantry angle miscalibrations were detected within 0.1. Conclusions: MPC is a useful tool for QA of

  10. TU-F-BRE-07: In Vivo Neutron Detection in Patients Undergoing Stereotactic Ablative Radiotherapy (SABR) for Primary Kidney Cancer Using 6Li and 7Li Enriched TLD Pairs

    SciTech Connect (OSTI)

    Lonski, P; Kron, T; Franich, R; Keehan, S; Siva, S; Taylor, M

    2014-06-15

    Purpose: Stereotactic ablative radiotherapy (SABR) for primary kidney cancer often involves the use of high-energy photons combined with a large number of monitor units. While important for risk assessment, the additional neutron dose to untargeted healthy tissue is not accounted for in treatment planning. This work aims to detect out-of-field neutrons in vivo for patients undergoing SABR with high-energy (>10 MV) photons and provides preliminary estimates of neutron effective dose. Methods: 3 variations of high-sensitivity LiF:Mg,Cu,P thermoluminescent dosimeter (TLD) material, each with varying {sup 6}Li / {sup 7}Li concentrations, were used in custom-made Perspex holders for in vivo measurements. The variation in cross section for thermal neutrons between Li isotopes was exploited to distinguish neutron from photon signal. Measurements were made out-of-field for 7 patients, each undergoing 3D-conformal SABR treatment for primary kidney cancer on a Varian 21iX linear accelerator. Results: In vivo measurements show increased signal for the {sup 6}Li enriched material for patients treated with 18 MV photons. Measurements on one SABR patient treated using only 6 MV showed no difference between the 3 TLD materials. The out-of-field photon signal decreased exponentially with distance from the treatment field. The neutron signal, taken as the difference between {sup 6}Li enriched and {sup 7}Li enriched TLD response, remains almost constant up to 50 cm from the beam central axis. Estimates of neutron effective dose from preliminary TLD calibration suggest between 10 and 30 mSv per 1000 MU delivered at 18 MV for the 7 patients. Conclusion: TLD was proven to be a useful tool for the purpose of in vivo neutron detection at out-of-field locations. Further work is required to understand the relationship between TL signal and neutron dose. Dose estimates based on preliminary TLD calibration in a neutron beam suggest the additional neutron dose was <30 mSv per 1000 MU at 18 MV.

  11. SU-E-J-205: Monte Carlo Modeling of Ultrasound Probes for Real-Time Ultrasound Image-Guided Radiotherapy

    SciTech Connect (OSTI)

    Hristov, D; Schlosser, J; Bazalova, M; Chen, J

    2014-06-01

    Purpose: To quantify the effect of ultrasound (US) probe beam attenuation for radiation therapy delivered under real-time US image guidance by means of Monte Carlo (MC) simulations. Methods: MC models of two Philips US probes, an X6-1 matrix-array transducer and a C5-2 curved-array transducer, were built based on their CT images in the EGSnrc BEAMnrc and DOSXYZnrc codes. Due to the metal parts, the probes were scanned in a Tomotherapy machine with a 3.5 MV beam. Mass densities in the probes were assigned based on an electron density calibration phantom consisting of cylinders with mass densities between 0.2–8.0 g/cm{sup 3}. Beam attenuation due to the probes was measured in a solid water phantom for a 6 MV and 15 MV 15x15 cm{sup 2} beam delivered on a Varian Trilogy linear accelerator. The dose was measured with the PTW-729 ionization chamber array at two depths and compared to MC simulations. The extreme case beam attenuation expected in robotic US image guided radiotherapy for probes in upright position was quantified by means of MC simulations. Results: The 3.5 MV CT number to mass density calibration curve was found to be linear with R{sup 2} > 0.99. The maximum mass densities were 4.6 and 4.2 g/cm{sup 3} in the C5-2 and X6-1 probe, respectively. Gamma analysis of the simulated and measured doses revealed that over 98% of measurement points passed the 3%/3mm criteria for both probes and measurement depths. The extreme attenuation for probes in upright position was found to be 25% and 31% for the C5-2 and X6-1 probe, respectively, for both 6 and 15 MV beams at 10 cm depth. Conclusion: MC models of two US probes used for real-time image guidance during radiotherapy have been built. As a Result, radiotherapy treatment planning with the imaging probes in place can now be performed. J Schlosser is an employee of SoniTrack Systems, Inc. D Hristov has financial interest in SoniTrack Systems, Inc.

  12. Growth of large single crystals of MgO

    SciTech Connect (OSTI)

    Boatner, L.A.; Urbanik, M.

    1997-06-12

    The progressive identification of new high-technology applications and requirements for MgO single crystals in the commercial realm, as well as in DOE and other government-agency project areas, has resulted in an increased demand and international market for this material. Specifically, the demand for MgO crystals in large sizes and quantities is presently increasing due to existing and developing applications that include: (a) MgO substrates for the formation of electro-optic thin films and devices, (b) epitaxial substrates for high-temperature thin-film superconducting devices MgO optical components - including high-temperature windows, lenses, and prisms, and (d) specialty MgO crucibles and evaporation sources for thin-film production. In the course of CRADA ORNL92-0091, carried out with Commercial Crystal Laboratories of Naples, Florida as the commercial participant, we have made major progress in increasing the size of single crystals of MgO produced by means of the submerged-arc-fusion technique-thereby increasing the commercial utility of this material. Prior to the accomplishments realized in the course of this CRADA, the only commercially available single crystals of MgO were produced in Japan, Israel, and Russia. The results achieved in the course of CRADA ORNL92-0091 have now led to the establishment of a domestic commercial source of MgO single-crystal substrates and components, and the U.S. is no longer totally dependent on foreign sources of this increasingly important material.

  13. Sociological survey in a municipality with a high level separate collection programme in an area of historic unpopularity

    SciTech Connect (OSTI)

    De Feo, Giovanni

    2014-08-15

    Highlights: • Behaviours, opinions and knowledge of citizens on MSW management were investigated. • The knowledge level was better than that of nearby university students and citizens. • The higher the education level, the greater the level of knowledge was. • The local authority showed a leading role in terms of waste management. • Trust is the key to any social program success including waste management programs. - Abstract: Behaviours, opinions and knowledge of citizens on MSW and separate collection were investigated in the city of Mercato San Severino (about 22,000 people), in the Campania region of Southern Italy that is an area suffering from a serious solid waste emergency that has lasted over 17 years due to the absence of treatment facilities. The image of heaps of rubbish in the streets of Naples and other nearby cities is only one side of the coin. Mercato San Severino has adopted an effective kerbside collection system since 2001 and a pay-as-you-throw program during 2005, guaranteeing more than the minimum level of recycling required by the Italian legislation. Structured questionnaires were administered to a sample of 500 people in 2010. Chi-square tests of independence were applied to state whether the differences were statistically significant (5%). About 90% of the sample stated that the success of the separate collection program was due to either the citizens and local authority or only the local authority, highlighting the leading role of the local authority and confirming that trust is the key to any social program success. The registered level of knowledge was better than that of nearby university students and citizens. The higher the education level, the greater the level of knowledge was.

  14. Case study installation of a HDPE curtain wall with sheetpile tie-in on both ends

    SciTech Connect (OSTI)

    Schindler, R.M.; Maltese, P.C.

    1997-12-31

    The plans for eliminating the off-site migration of non-aqueous phase liquid (NAPL) from a refinery into a nearby river included the installation of a High Density Polyethylene (HDPE) curtain wall and an underdrain system. A 640 m (2100 lineal feet) HDPE Curtain Wall was installed along the river boundary, tying into an existing sheet pile wall on both ends. The wall varied from approximately 4.5 m (15 feet) deep at the northern end to about 7 m (23 feet) deep at the southern end, running approximately 3 to 3.6 m (10 to 12 feet) inland of an existing wooden bulkhead. The curtain wall was successfully installed through a slurry supported trench. A 930 m (3050 lineal feet) interception/collection trench was installed parallel to the HDPE Curtain Wall, continuing on beyond the curtain wall on the southern end. The depth of the trench varied from approximately 3 to 4 m (10 to 13 feet) deep. A 20.32 cm (8 inch) diameter perforated HDPE header pipe was placed in the trench to convey groundwater and product to two sumps. The trench is 53.34 cm (21 inches) wide and contained aggregate to approximately 0.9 m (3 feet) below ground. This work was accomplished using the bio-polymer slurry drainage trench (BP Drain) technique. This paper briefly describes the construction methods utilized during this project, specifically HDPE curtain wall installation thru a bentonite slurry and tie-in to the existing sheet pile wall.

  15. Advanced hydraulic fracturing methods to create in situ reactive barriers

    SciTech Connect (OSTI)

    Murdoch, L. |; Siegrist, B.; Vesper, S.

    1997-12-31

    Many contaminated areas consist of a source area and a plume. In the source area, the contaminant moves vertically downward from a release point through the vadose zone to an underlying saturated region. Where contaminants are organic liquids, NAPL may accumulate on the water table, or it may continue to migrate downward through the saturated region. Early developments of permeable barrier technology have focused on intercepting horizontally moving plumes with vertical structures, such as trenches, filled with reactive material capable of immobilizing or degrading dissolved contaminants. This focus resulted in part from a need to economically treat the potentially large volumes of contaminated water in a plume, and in part from the availability of construction technology to create the vertical structures that could house reactive compounds. Contaminant source areas, however, have thus far remained largely excluded from the application of permeable barrier technology. One reason for this is the lack of conventional construction methods for creating suitable horizontal structures that would place reactive materials in the path of downward-moving contaminants. Methods of hydraulic fracturing have been widely used to create flat-lying to gently dipping layers of granular material in unconsolidated sediments. Most applications thus far have involved filling fractures with coarse-grained sand to create permeable layers that will increase the discharge of wells recovering contaminated water or vapor. However, it is possible to fill fractures with other compounds that alter the chemical composition of the subsurface. One early application involved development and field testing micro-encapsulated sodium percarbonate, a solid compound that releases oxygen and can create aerobic conditions suitable for biodegradation in the subsurface for several months.

  16. Tmvoc-React

    Energy Science and Technology Software Center (OSTI)

    2008-02-12

    The TMVOC-REACT simulator was generated by replacing the fluid and heat flow part, TOUGH2, in TOUGHREACT with TMVOC. Both programs have been distributed to the public through the US Department of Energy's Energy Science and Technology Software Center. TMVOC is a program for three-phase non-isothermal flows of multi-component hydrocarbon mixtures in variably saturated heterogeneous media. TMVOC was initially designed for studying subsurface contamination by volatile organic compounds (VOCs), such as hydrocarbon fuels and industrial solvents.more » It can model the one-, two-, or three-dimensional migration of non-aqueous phase liquids (NAPLs) through the unsaturated and saturated zones, the formation of an oil lens on the water table, the dissolution and subsequent transport of VOCs in groundwater, as well as the vaporization and migration of VOCs in the interstitial air of the unsaturated zone. TOUGHREACT is a numerical simulation program for chemically reactive nonisothermal flows of multiphase fluids in porous and fractured media. A variety of subsurface thermo-physical-chemical processes can be considered under a wide range of conditions of pressure, temperature, water saturation, ionic strength, pH and Eh. Intractions between mineral assemblages and fluids can occur under local equilibrium or kinetic rates. The gas phase can be chemically active. Precipitation and dissolution reactions can change formation porosity and permeability. The program can be applied to many geologic systems and environmental problems, including geothermal systems, diagenetic and weathering processes, subsurface waste disposal, aid mine drainage remediation, and contaminant transport.« less

  17. Beam characteristics of energy-matched flattening filter free beams

    SciTech Connect (OSTI)

    Paynter, D.; Weston, S. J.; Cosgrove, V. P.; Evans, J. A.; Thwaites, D. I.

    2014-05-15

    Purpose: Flattening filter free (FFF) linear accelerators can increase treatment efficiency and plan quality. There are multiple methods of defining a FFF beam. The Elekta control system supports tuning of the delivered FFF beam energy to enable matching of the percentage depth-dose (PDD) of the flattened beam at 10 cm depth. This is compared to FFF beams where the linac control parameters are identical to those for the flattened beam. All beams were delivered on an Elekta Synergy accelerator with an Agility multi-leaf collimator installed and compared to the standard, flattened beam. The aim of this study is to compare “matched” FFF beams to both “unmatched” FFF beams and flattened beams to determine the benefits of matching beams. Methods: For the three modes of operation 6 MV flattened, 6 MV matched FFF, 6 MV unmatched FFF, 10 MV flattened, 10 MV matched FFF, and 10 MV unmatched FFF beam profiles were obtained using a plotting tank and were measured in steps of 0.1 mm in the penumbral region. Beam penumbra was defined as the distance between the 80% and 20% of the normalized dose when the inflection points of the unflattened and flattened profiles were normalized with the central axis dose of the flattened field set as 100%. PDD data was obtained at field sizes ranging from 3 cm × 3 cm to 40 cm × 40 cm. Radiation protection measurements were additionally performed to determine the head leakage and environmental monitoring through the maze and primary barriers. Results: No significant change is made to the beam penumbra for FFF beams with and without PDD matching, the maximum change in penumbra for a 10 cm × 10 cm field was within the experimental error of the study. The changes in the profile shape with increasing field size are most significant for the matched FFF beam, and both FFF beams showed less profile shape variation with increasing depth when compared to flattened beams, due to consistency in beam energy spectra across the radiation field

  18. The RR Lyrae stars: New perspectives

    SciTech Connect (OSTI)

    McNamara, D. H.; Barnes, J. E-mail: jonathan.barnes@slcc.edu

    2014-02-01

    We demonstrate that the Oosterhoff II (Oo II) RR Lyrae ab variables are hotter by ?270 K, at the same period, than Oo I variables. Or, at the same ((B) (V)){sub 0} value the Oo II variables have larger radii than Oo I variables. This accounts for the reason Oo II variables are brighter (0.12-0.20 mag) than Oo I variables. The dependence of the light amplitude of RR Lyrae variables on temperature is independent of Oo type. This makes it possible to derive an accurate set of equations to relate intrinsic (B V){sub 0} color indices to light amplitudes, which in turn can be used to determine the interstellar reddening (E (B V)). With just a few variables (?5), it is possible to determine the E (B V) to an accuracy of <0.01 mag in the absence of systematic photometric errors. We discuss the errors introduced in color excess determinations by including the Blazhko stars in a solution. A comparison of color excess values of 23 globular clusters and two regions of the Large Magellanic Cloud (LMC), determined with the aid of our newly developed equations, are found to compare favorably (?0.01 mag) with color excess values found in the literature. Four new Oo III variables, some found in metal-poor clusters, are discussed. An analysis of the galactic-field variables indicates the majority are Oo I and Oo II variables, but a few short-period (log P < 0.36) metal-strong variables, so far not found in galactic globular clusters are evidently ?0.30 mag fainter than Oo I variables. Oo III variables may also be present in the field. We conclude that the RR Lyrae ab variables are primarily restricted to four sequences or groups. If we assume that the Oo I variables' mean absolute magnitude is Mv = 0.61, the mean absolute magnitudes of the other three sequences are: short-period variables Mv ? 0.89 mag, Oo II Mv ? 0.43 mag, and Oo III Mv ? 0.29 mag. The Oo I fundamental RR Lyrae ab red edge (FRE) and fundamental blue edge (FBE) occur at approximately the following

  19. SU-E-T-570: Management of Radiation Oncology Patients with Cochlear Implant and Other Bionic Devices in the Brain and Head and Neck Regions

    SciTech Connect (OSTI)

    Guo, F.Q; Chen, Z; Nath, R

    2014-06-01

    Purpose: To investigate the current status of clinical usage of cochlear implant (CI) and other bionic devices (BD) in the brain and head and neck regions (BH and N) and their management in patients during radiotherapy to ensure patient health and safety as well as optimum radiation delivery. Methods: Literature review was performed with both CIs and radiotherapy and their variants as keywords in PubMed, INSPEC and other sources. The focus was on CIs during radiotherapy, but it also included other BDs in BHȦN, such as auditory brainstem implant, bionic retinal implant, and hearing aids, among others. Results: Interactions between CIs and radiation may cause CIs malfunction. The presence of CIs may also cause suboptimum dose distribution if a treatment plan was not well designed. A few studies were performed for the hearing functions of CIs under irradiations of 4 MV and 6 MV x-rays. However, x-rays with higher energies (10 to 18 MV) broadly used in radiotherapy have not been explored. These higher energetic beams are more damaging to electronics due to strong penetrating power and also due to neutrons generated in the treatment process. Modern CIs are designed with more and more complicated integrated circuits, which may be more susceptible to radiation damage and malfunction. Therefore, careful management is important for safety and treatment outcomes. Conclusion: Although AAPM TG-34, TG-63, and TG-203 (update of TG-34, not published yet) reports may be referenced for management of CIs and other BDs in the brain and H and N regions, a site- and device-specified guideline should be developed for CIs and other BDs. Additional evaluation of CI functions under clinically relevant set-ups should also be performed to provide clinicians with better knowledge in clinical decision making.

  20. Quench Studies of Six High Temperature Nitrogen Doped 9 Cell Cavities for Use in the LCLS-II Baseline Prototype Cryomodule at Jefferson Laboratory

    SciTech Connect (OSTI)

    Palczewski, Ari; Geng, Rongli; Eremeev, Grigory; Reece, Charles

    2015-09-01

    Jefferson Lab (JLab) processed six nine-cell cavities as part of a small-scale production for LCLS-II cavity processing development utilizing the promising nitrogen-doping process. [1] Various nitrogen-doping recipes have been scrutinized to optimize process parameters with the aim to guarantee an unloaded quality factor (Q 0) of 2.7·1010 at an accelerating field (Eacc) of 16 MV/m at 2.0 K in the cryomodule. During the R&D phase the characteristic Q0 vs. Eacc performance curve of the cavities has been measured in JLab’s vertical test area at 2 K. The findings showed the characteristic rise of the Q0 with Eacc as expected from nitrogen-doping. Initially, five cavities achieved an average Q0 of 3.3·1010 at the limiting Eacc averaging to 16.8 MV/m, while one cavity experienced an early quench accompanied by an unusual Q 0 vs. Eacc curve. The project accounts for a cavity performance loss from the vertical dewar test (with or without the helium vessel) to the horizontal performance in a cryomodule, such that these results leave no save margin to the cryomodule specification. Consequently, a refinement of the nitrogen-doping has been initiated to guarantee an average quench field above 20 MV/m without impeding the Q 0. This paper covers the refinement work performed for each cavity, which depends on the initial results, as well as a quench analysis carried out before and after the rework during the vertical RF tests as far as applicable.

  1. Remnant PbI{sub 2}, an unforeseen necessity in high-efficiency hybrid perovskite-based solar cells?

    SciTech Connect (OSTI)

    Cao, Duyen H.; Stoumpos, Constantinos C.; Malliakas, Christos D.; Katz, Michael J.; Hupp, Joseph T. E-mail: m-kanatzidis@northwestern.edu; Kanatzidis, Mercouri G. E-mail: m-kanatzidis@northwestern.edu; Farha, Omar K.

    2014-09-01

    Perovskite-containing solar cells were fabricated in a two-step procedure in which PbI{sub 2} is deposited via spin-coating and subsequently converted to the CH{sub 3}NH{sub 3}PbI{sub 3} perovskite by dipping in a solution of CH{sub 3}NH{sub 3}I. By varying the dipping time from 5 s to 2 h, we observe that the device performance shows an unexpectedly remarkable trend. At dipping times below 15 min the current density and voltage of the device are enhanced from 10.1 mA/cm{sup 2} and 933 mV (5 s) to 15.1 mA/cm{sup 2} and 1036 mV (15 min). However, upon further conversion, the current density decreases to 9.7 mA/cm{sup 2} and 846 mV after 2 h. Based on X-ray diffraction data, we determined that remnant PbI{sub 2} is always present in these devices. Work function and dark current measurements showed that the remnant PbI{sub 2} has a beneficial effect and acts as a blocking layer between the TiO{sub 2} semiconductor and the perovskite itself reducing the probability of back electron transfer (charge recombination). Furthermore, we find that increased dipping time leads to an increase in the size of perovskite crystals at the perovskite-hole-transporting material interface. Overall, approximately 15 min dipping time (?2% unconverted PbI{sub 2}) is necessary for achieving optimal device efficiency.

  2. Overview of high gradient SRF R&D for ILC cavities at Jefferson Lab

    SciTech Connect (OSTI)

    Geng, Rongli [JLAB

    2009-11-01

    We report the progress on high gradient R&D of ILC cavities at Jefferson Lab (JLab) since the Beijing workshop. Routine 9-cell cavity electropolishing (EP) processing and RF testing has been enhanced with added surface mapping and T-mapping instrumentations. 12 new 9-cell cavities (10 of them are baseline fine-grain TESLA-shape cavities: 5 built by ACCEL/Research Instruments, 4 by AES and 1 by JLab; 2 of them are alternative cavities: 1 fine-grain ICHIRO-shape cavity built by KEK/Japan industry and 1 large-grain TESLA-shape cavity built by JLab) are EP processed and tested. 76 EP cycles are accumulated, corresponding to more than 200 hours of active EP time. Field emission (FE) and quench behaviors of electropolished 9-cell cavities are studied. EP process continues to be optimized, resulting in advanced procedures and hence improved cavity performance. Several 9-cell cavities reached 35 MV/m after the first light EP processing. FE-free performance has been demonstrated in 9-cell cavities in 35-40 MV/m range. 1-cell cavity studies explore new techniques for defect removal as well as advanced integrated cavity processing. Surface studies of niobium samples electropolished together with real cavities provide new insight into the nature of field emitters. Close cooperation with the US cavity fabrication industry has been undertaking with the successful achievement of 41 MV/m for the first time in a 9-cell ILC cavity built by AES. As the size of the data set grows, it is now possible to construct gradient yield curves, from which one can see that significant progress has been made in raising the high gradient yield.

  3. Poster — Thur Eve — 42: Radiochromic film calibration for low-energy seed brachytherapy dose measurement

    SciTech Connect (OSTI)

    Morrison, H; Menon, G; Sloboda, R

    2014-08-15

    The purpose of this study was to investigate the accuracy of radiochromic film calibration procedures used in external beam radiotherapy when applied to I-125 brachytherapy sources delivering higher doses, and to determine any necessary modifications to achieve similar accuracy in absolute dose measurements. GafChromic EBT3 film was used to measure radiation doses upwards of 35 Gy from 6 MV, 75 kVp and (∼28 keV) I-125 photon sources. A custom phantom was used for the I-125 irradiations to obtain a larger film area with nearly constant dose to reduce the effects of film heterogeneities on the optical density (OD) measurements. RGB transmission images were obtained with an Epson 10000XL flatbed scanner, and calibration curves relating OD and dose using a rational function were determined for each colour channel and at each energy using a non-linear least square minimization method. Differences found between the 6 MV calibration curve and those for the lower energy sources are large enough that 6 MV beams should not be used to calibrate film for low-energy sources. However, differences between the 75 kVp and I-125 calibration curves were quite small; indicating that 75 kVp is a good choice. Compared with I-125 irradiation, this gives the advantages of lower type B uncertainties and markedly reduced irradiation time. To obtain high accuracy calibration for the dose range up to 35 Gy, two-segment piece-wise fitting was required. This yielded absolute dose measurement accuracy above 1 Gy of ∼2% for 75 kVp and ∼5% for I-125 seed exposures.

  4. Anaerobic oxidation of short-chain alkanes in hydrothermal sediments: potential influences on sulfur cycling and microbial diversity

    SciTech Connect (OSTI)

    Adams, MM; Hoarfrost, AL; Bose, A; Joye, SB; Girguis, PR

    2013-05-14

    Short-chain alkanes play a substantial role in carbon and sulfur cycling at hydrocarbon-rich environments globally, yet few studies have examined the metabolism of ethane (C-2), propane (C-3), and butane (C-4) in anoxic sediments in contrast to methane (C-1). In hydrothermal vent systems, short-chain alkanes are formed over relatively short geological time scales via thermogenic processes and often exist at high concentrations. The sediment-covered hydrothermal vent systems at Middle Valley (MV Juan de Fuca Ridge) are an ideal site for investigating the anaerobic oxidation of C-1-C-4 alkanes, given the elevated temperatures and dissolved hydrocarbon species characteristic of these metalliferous sediments. We examined whether MV microbial communities oxidized C-1-C-4 alkanes under mesophilic to thermophilic sulfate-reducing conditions. Here we present data from discrete temperature (25, 55, and 75 degrees C) anaerobic batch reactor incubations of MV sediments supplemented with individual alkanes. Co-registered alkane consumption and sulfate reduction (SR) measurements provide clear evidence for C-1-C-4 alkane oxidation linked to SR over time and across temperatures. In these anaerobic batch reactor sediments, 16S ribosomal RNA pyrosequencing revealed that Deltaproteobacteria, particularly a novel sulfate-reducing lineage, were the likely phylotypes mediating the oxidation of C-2-C-4 alkanes. Maximum C-1-C-4 alkane oxidation rates occurred at 55 degrees C, which reflects the mid-core sediment temperature profile and corroborates previous studies of rate maxima for the anaerobic oxidation of methane (AOM). Of the alkanes investigated, C-3 was oxidized at the highest rate over time, then C-4, C-2, and C-1, respectively. The implications of these results are discussed with respect to the potential competition between the anaerobic oxidation of C-2-C(4)alkanes with AOM for available oxidants and the influence on the fate of C-1 derived from these hydrothermal systems.

  5. RF Processing Experience with the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Schmerge, J.F.

    2010-11-24

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. A total of five different metal cathodes (4 Cu and 1 Mg) have been installed on the GTF gun. The rf processing history with the different cathodes will be presented including peak field achieved at the cathode. The LCLS gun is intended to operate at 120 MV/m and fields up to 140 MV/m have been achieved in the GTF gun. After installing a new cathode the number of rf pulses required to reach 120 MV/m is approximately 5-10 million. Total emitted dark current and Fowler Nordheim plots are also shown over the life of the cathode. The GTF photo-injector gun is an S-band standing-wave structure, with two resonant cavities and an intervening thick washer (Figure 1). The flat, back wall of the first cavity is a copper plate that serves as photocathode when illuminated with ultraviolet light from a pulsed, high-power laser. RF power enters the gun through an iris on the outer wall of the second cavity, and is coupled to the first through the axial opening of the washer. The first cavity is often referred to as a half cell, because its full-cell length has been truncated by the cathode plate and the second cavity is called the full cell. The gun is designed to operate in a {pi} mode, with the peak field on axis in each cell approximately equal. The maximum in the half cell occurs at the cathode, and in the full cell near the center of the cavity. The field profile and tuning procedures are discussed in a separate tech note [1].

  6. SciThur AM: YIS - 04: Gold Nanoparticle Enhanced Arc Radiotherapy: A Monte Carlo Feasibility Study

    SciTech Connect (OSTI)

    Koger, B; Kirkby, C

    2014-08-15

    Introduction: The use of gold nanoparticles (GNPs) in radiotherapy has shown promise for therapeutic enhancement. In this study, we explore the feasibility of enhancing radiotherapy with GNPs in an arc-therapy context. We use Monte Carlo simulations to quantify the macroscopic dose-enhancement ratio (DER) and tumour to normal tissue ratio (TNTR) as functions of photon energy over various tumour and body geometries. Methods: GNP-enhanced arc radiotherapy (GEART) was simulated using the PENELOPE Monte Carlo code and penEasy main program. We simulated 360 arc-therapy with monoenergetic photon energies 50 1000 keV and several clinical spectra used to treat a spherical tumour containing uniformly distributed GNPs in a cylindrical tissue phantom. Various geometries were used to simulate different tumour sizes and depths. Voxel dose was used to calculate DERs and TNTRs. Inhomogeneity effects were examined through skull dose in brain tumour treatment simulations. Results: Below 100 keV, DERs greater than 2.0 were observed. Compared to 6 MV, tumour dose at low energies was more conformai, with lower normal tissue dose and higher TNTRs. Both the DER and TNTR increased with increasing cylinder radius and decreasing tumour radius. The inclusion of bone showed excellent tumour conformality at low energies, though with an increase in skull dose (40% of tumour dose with 100 keV compared to 25% with 6 MV). Conclusions: Even in the presence of inhomogeneities, our results show promise for the treatment of deep-seated tumours with low-energy GEART, with greater tumour dose conformality and lower normal tissue dose than 6 MV.

  7. SU-E-T-602: Beryllium Seeds Implant for Photo-Neutron Yield Using External Beam Therapy

    SciTech Connect (OSTI)

    Koren, S; Veltchev, I; Furhang, E

    2014-06-01

    Purpose: To evaluate the Neutron yield obtained during prostate external beam irradiation. Methods: Neutrons, that are commonly a radiation safety concern for photon beams with energy above 10 MV, are induced inside a PTV from Beryllium implemented seeds. A high megavoltage photon beam delivered to a prostate will yield neutrons via the reaction Be-9(?,n)2?. Beryllium was chosen for its low gamma,n reaction cross-section threshold (1.67 MeV) to be combined with a high feasible 25 MV photon beam. This beam spectra has a most probable photon energy of 2.5 to 3.0 MeV and an average photon energy of about 5.8 MeV. For this feasibility study we simulated a Beryllium-made common seed dimension (0.1 cm diameter and 0.5 cm height) without taking into account encapsulation. We created a 0.5 cm grid loading pattern excluding the Urethra, using Variseed (Varian inc.) A total of 156 seeds were exported to a 4cm diameter prostate sphere, created in Fluka, a particle transport Monte Carlo Code. Two opposed 25 MV beams were simulated. The evaluation of the neutron dose was done by adjusting the simulated photon dose to a common prostate delivery (e.g. 7560 cGy in 42 fractions) and finding the corresponding neutron dose yield from the simulation. A variance reduction technique was conducted for the neutrons yield and transported. Results: An effective dose of 3.65 cGy due to neutrons was found in the prostate volume. The dose to central areas of the prostate was found to be about 10 cGy. Conclusion: The neutron dose yielded does not justify a clinical implant of Beryllium seeds. Nevertheless, one should investigate the Neutron dose obtained when a larger Beryllium loading is combined with commercially available 40 MeV Linacs.

  8. Lessons learned in implementing a demand side management contract at the Presidio of San Francisco

    SciTech Connect (OSTI)

    Sartor, D.; Munn, M.

    1998-06-01

    The National Park Service (NSP) recently completed the implementation phase of its Power Saving Partners (PSP) Demand Side Management (DSM) contract with the local utility, Pacific Gas and Electric (PG&E). Through the DSM contract, NPS will receive approximately $4.1 million over eight years in payment for saving 61 kW of electrical demand, 179,000 km of electricity per year, and 1.1 million therms of natural gas per year. These payments are for two projects: the installation of high-efficiency lighting systems at the Thoreau Center for Sustainability and the replacement of an old central boiler plant with new, distributed boilers. Although these savings and payments are substantial, the electrical savings and contract payments fall well short of the projected 1,700 kW of electrical demand, 8 million kwh of annual electricity savings, and $11 million in payments, anticipated at the project's onset. Natural gas savings exceeded the initial forecast of 800,000 therms per year. The DSM contract payments did not meet expectations for a variety of reasons which fall into two broad categories: first, many anticipated projects were not constructed, and second, some of the projects that were constructed were not included in the program because the cost of implementing the DSM program's measurement and verification (M&V) requirements outweighed anticipated payments. This paper discusses the projects implemented, and examines the decisions made to withdraw some of them from the DSM contract. It also presents the savings that were realized and documented through M&V efforts. Finally, it makes suggestions relative to M&V protocols to encourage all efficiency measures, not just those that are easy to measure.

  9. Iron-mediated remediation of RDX-contaminated water and soil under controlled Eh/pH

    SciTech Connect (OSTI)

    Singh, J.; Comfort, S.D.; Shea, P.J.

    1999-05-01

    Soil and water contaminated with hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) is a serious environmental problem at several active and abandoned munitions production facilities. Zero-valent iron (Fe{sup 0}) can effectively remediate RDX-contaminated soil and water. The objective of this study was to manipulate Eh and pH for enhanced Fe{sup 0}-mediated destruction of RDX. This was accomplished by monitoring RDX destruction under controlled Eh-pH conditions (Eh: {minus}300 to +150 mV; pH: 2--10). Decreasing Eh and pH increased RDX destruction in aqueous solution. Treating 20 mg of RDX L{sup {minus}1} (90 {micro}M) under a static Eh of {minus}150 mV and pH 7 with 20 g of Fe{sup 0} L{sup {minus}1} removed 95% of the RDX within 4 h; no RDX was detected after 8 h. Treating a soil slurry (20% solids; 510 mg RDX kg{sup {minus}1} soil) with 20 g of Fe{sup 0} L{sup {minus}1} at an Eh of {minus}150 mV and pH 7 increased RDX destruction by 24% over the unbuffered control and resulted in 99% RDX destruction within 24 h. Adding 4.2 mM sodium sulfide (in lieu of a static Eh) under similar conditions resulted in 93% RDX loss within 24 h. Results indicated that lowering Eh and maintaining neutral pH during Fe{sup 0} treatment can increase RDX destruction in contaminated soil and water.

  10. Influence of compensator thickness, field size, and off-axis distance on the effective attenuation coefficient of a cerrobend compensator for intensity-modulated radiation therapy

    SciTech Connect (OSTI)

    Haghparast, Abbas; Hashemi, Bijan; Eivazi, Mohammad Taghi

    2013-04-01

    Intensity-modulated radiation therapy (IMRT) can be performed by using compensators. To make a compensator for an IMRT practice, it is required to calculate the effective attenuation coefficient (?{sub eff}) of its material, which is affected by various factors. We studied the effect of the variation of the most important factors on the calculation of the ?{sub eff} of the cerrobend compensator for 6-MV photon beams, including the field size, compensator thickness, and off-axis distance. Experimental measurements were carried out at 100 cm source-to-surface distance and 10 cm depth for the 6-MV photon beams of an Elekta linac using various field size, compensator thickness, and off-axis settings. The field sizes investigated ranged from 4 4 to 25 25 cm{sup 2} and the cerrobend compensator thicknesses from 0.56 cm. For a fixed compensator thickness, variation of the ?{sub eff} with the field size ranged from 3.76.8%, with the highest value attributed to the largest compensator thickness. At the reference field size of 10 10 cm{sup 2}, the ?{sub eff} varied by 16.5% when the compensator thickness was increased from 0.56 cm. However, the variation of the ?{sub eff} with the off-axis distance was only 0.99% at this field size, whereas for the largest field size, it was more significant. Our results indicated that the compensator thickness and field size have the most significant effect on the calculation of the compensator ?{sub eff} for the 6-MV photon beam. Therefore, it is recommended to consider these parameters when calculating the compensator thickness for an IMRT practice designed for these beams. The off-axis distance had a significant effect on the calculation of the ?{sub eff} only for the largest field size. Hence, it is recommended to consider the effect of this parameter only for field sizes larger than 25 25 cm{sup 2}.

  11. Continuous On-Line Partial Discharge Monitor for Medium-Voltage Cable Feasibility Study

    SciTech Connect (OSTI)

    M. Fenger

    2005-11-30

    Partial discharge (PD) assessment is one method of detecting cable conditions that predict approaching failure. While not all PDs in cable systems lead to failure, PDs within the cable's insulation can lead to relatively rapid failure. Accordingly, on-line PD assessment may be more useful than periodic PD assessment because the period of partial discharging at the end of a cable's life may be quite short. The research described in this report studied the feasibility of developing an on-line PD monitor for assessing both shielded and unshielded MV cables.

  12. Axis-1 diode simulations I: standard 2-inch cathode

    SciTech Connect (OSTI)

    Ekdahl, Carl [Los Alamos National Laboratory

    2011-01-11

    The standard configuration of the DARHT Axis-I diode features a 5.08-cm diameter velvet emitter mounted in the flat surface of the cathode shroud. The surface of the velvet is slightly recessed {approx}2.5 mm. This configuration produces a 1.75 kA beam when a 3.8-MV pulse is applied to the anode-cathode (AK) gap. This note addresses some of the physics of this diode through the use of finite-element simulations.

  13. Crab Crossing Schemes and Studies for Electron Ion Collider

    SciTech Connect (OSTI)

    S. Ahmed, Y. Derbenev, V. Morozov, A. Castilla, G.A. Krafft, B. Yunn, Y. Zhang, J.R. Delayen

    2011-09-01

    This report shows our progress in crab crossing consideration for future electron-ion collider envisioned at JLab. In this design phase, we are evaluating two crabbing schemes viz., the deflecting and dispersive. The mathematical formulations and lattice design for these schemes are discussed in this paper. Numerical simulations involving particle tracking through a realistic deflecting RF cavity and optics illustrate the desired crab tilt of 25 mrad for 1.35 MV. Evolution of beam propagation are shown which provides the physical insight of the crabbing phenomenon.

  14. TH-C-17A-04: Shining Light On the Implementation of Cherenkov Emission in Radiation Therapy

    SciTech Connect (OSTI)

    Zlateva, Y; Quitoriano, N

    2014-06-15

    Purpose: We hypothesize that Cherenkov emission (CE) by radiotherapy beams is correlated with radiation dose, CE detection can be maximized by a spectral shift towards the near-infrared (NIR) window of biological tissue, and in certain tissue types (ex. breast/oropharynx), it could prove superior to mega-voltage (MV) imaging. Therefore, we compare CE imaging to onboard MV imaging. Methods: Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissuesimulating phantom composed of water, fat emulsion, and beef blood; plastic phantom with solid water insert. The optical spectrometry system consisted of a multi-mode optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated charge-coupled device (CCD). CdSe/ZnS quantum dots (QDs), emitting at (650±10) nm, were used to achieve NIR shift of the CE signal. CE and MV images were acquired with a complementary metal-oxide-semiconductor (CMOS) camera and an electronic portal imaging device (EPID), respectively. Results: MC and experimental studies indicate a strong linear correlation between radiation dose and CE (Pearson coefficient > 0.99). CE by an 18 MeV beam was effectively shifted towards the NIR in water and in a tissue-simulating phantom, exhibiting a 50% increase at 650 nm for QD depths of ∼3 mm. CE images exhibited relative contrast superior to EPID images by a factor of 30. Conclusion: Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing, and QDs can be used to improve CE detectability, yielding image quality superior to MV imaging for the case of low density variability, low optical attenuation materials, such as breast or oropharyngeal cavities. Ongoing work involves microenvironment functionalization of QDs and application of multichannel

  15. A practical and theoretical definition of very small field size for radiotherapy output factor measurements

    SciTech Connect (OSTI)

    Charles, P. H. Crowe, S. B.; Langton, C. M.; Trapp, J. V.; Cranmer-Sargison, G.; Thwaites, D. I.; Kairn, T.; Knight, R. T.; Kenny, J.

    2014-04-15

    Purpose: This work introduces the concept of very small field size. Output factor (OPF) measurements at these field sizes require extremely careful experimental methodology including the measurement of dosimetric field size at the same time as each OPF measurement. Two quantifiable scientific definitions of the threshold of very small field size are presented. Methods: A practical definition was established by quantifying the effect that a 1 mm error in field size or detector position had on OPFs and setting acceptable uncertainties on OPF at 1%. Alternatively, for a theoretical definition of very small field size, the OPFs were separated into additional factors to investigate the specific effects of lateral electronic disequilibrium, photon scatter in the phantom, and source occlusion. The dominant effect was established and formed the basis of a theoretical definition of very small fields. Each factor was obtained using Monte Carlo simulations of a Varian iX linear accelerator for various square field sizes of side length from 4 to 100 mm, using a nominal photon energy of 6 MV. Results: According to the practical definition established in this project, field sizes ?15 mm were considered to be very small for 6 MV beams for maximal field size uncertainties of 1 mm. If the acceptable uncertainty in the OPF was increased from 1.0% to 2.0%, or field size uncertainties are 0.5 mm, field sizes ?12 mm were considered to be very small. Lateral electronic disequilibrium in the phantom was the dominant cause of change in OPF at very small field sizes. Thus the theoretical definition of very small field size coincided to the field size at which lateral electronic disequilibrium clearly caused a greater change in OPF than any other effects. This was found to occur at field sizes ?12 mm. Source occlusion also caused a large change in OPF for field sizes ?8 mm. Based on the results of this study, field sizes ?12 mm were considered to be theoretically very small for 6 MV beams

  16. Heavy Ion Fusion Accelerator Research (HIFAR) year-end report, April 1, 1989--September 30, 1989

    SciTech Connect (OSTI)

    Not Available

    1989-12-01

    This report contains the following topics on heavy ion fusion: MBE-4 drifting beam quadrupole operating range; transverse emittance growth in MBE-4; an improved ion source for MBE-4; drifting beam studies on MBE-4; 2-MV injector; improvements in lifetime of the C{sup +} source; injector control system; Maxwell spark gap test update; ILSE cosine 2{theta} quadrupole magnet development; electrostatic quadrupole prototype development activity; induction accelerator cell development; effect of a spread in beamlet currents on longitudinal stability; and heavy ion linac driver analysis.

  17. Heavy Ion Fusion Accelerator Research (HIFAR) half-year report, October 1, 1989--March 31, 1990

    SciTech Connect (OSTI)

    Not Available

    1990-03-01

    This report discusses the following topics: Transverse Emittance Studies on MBE-4; MBE-4 Simulations; Beam Centroid Motion and Misalignments in MBE-4; Survey and Alignment of MBE-4; Energy Analysis of the 5mA MBE-4 Beam; An Improved 10 mA Ion Source for MBE-4; Emittance Degradation via a Wire Grid; Ion Source Development; 2 MV Injector; Electrostatic Quadrupole Prototype Development Activity; Magnetic Induction Core Studies; A Preliminary Consideration of Beam Splitting in Momentum Space; and Status of the Optimization Code HILDA.

  18. Innovative Demonstration Platform: PEC

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    JOINT CENTER FOR ARTIFICIAL PHOTOSYNTHESIS SOLAR PEC H 2 DEVICES FRANCES HOULE AWSM workshop April 14-15, 2016 LAWRENCE BERKELEY NATIONAL LABORATORY THE STATE OF THE ART Fraunhofer/JCAP JCAP JCAP JCAP JCAP 2016 >15% JCAP Updated with 2015-16 demonstrations DEVICE TYPES FOR DEMONSTRATIONS 10% PLANAR DEVICE: THE LOUVERED DESIGN WITH FULL PRODUCT SEPARATION Potential (mV) Cell parameters: PV width = 1.43 cm Nafion height = 3.10 mm Channel height = 3.25 mm Catalysts: IrO 2 and Pt Solution: 1 M H

  19. Infrared response of YBa sub 2 Cu sub 3 O sub 7-. delta. films to pulsed, broadband synchrotron radiation

    SciTech Connect (OSTI)

    Carr, G.L.; Quijada, M.; Tanner, D.B. . Dept. of Physics); Hirschmugl, C.J.; Williams, G.P. ); Etemad, S.; DeRosa, F.; Venkatesan, T. ); Dutta, B.; Hemmick, D.; Xi, X. . Dept. of Physics)

    1990-01-01

    We report studies of a thin high {Tc} film operating as a fast bolometric detector of infrared radiation. The film has a response of infrared radiation. The film has a response of several mV when exposed to a 1 W, 1 ns duration broadband infrared pulse. The decay after the pulse was about 4 ns. The temperature dependence of the response accurately tracked dR/dT. A thermal model, in which the film's temperature varies relative to the substrate, provides a good description of the response. We find no evidence for other (non-bolometric) response mechanisms for temperatures near or well below {Tc}. 13 refs., 4 figs.

  20. HSI Usage

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Usage HSI Usage HSI is a flexible and powerful command-line utility to access the NERSC HPSS storage systems. Like FTP, you can use it to store and retrieve files but it has a much larger set of commands for listing your files and directories, creating directories, changing file permissions, etc. The command set has a UNIX look and feel (e.g. mv, mkdir, rm, cp, cd, etc.) so that moving through your HPSS directory tree is almost identical to what you would find on a UNIX file system. HSI can be

  1. Result of MHI 2-Cell Seamless Dumb-Bell Cavity Vertical Test

    SciTech Connect (OSTI)

    Okihira, K.; Hara, H.; Ikeda, N.; Inoue, F.; Sennyu, K.; Geng, Rongli; Rimmer, Robert A.; Kako, E.

    2014-12-01

    MHI have supplied several 9-cell cavities for STF (R&D of ILC project at KEK) and have been considering production method for stable quality and cost reduction, seamless dumb-bell cavity was one of them. We had fabricated a 2 cell seamless dumb-bell cavity for cost reduction and measured RF performance in collaboration with JLab, KEK and MHI. Surface treatment recipe for ILC was applied for MHI 2-cell cavity and vertical test was performed at JLab. The cavity reached Eacc=32.4MV/m after BCP and EP. Details of the result are reported.

  2. EBT GAFCHROMIC{sup TM} film dosimetry in compensator-based intensity modulated radiation therapy

    SciTech Connect (OSTI)

    Vaezzadeh, Seyedali [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Allahverdi, Mahmoud, E-mail: alahverdi@sina.tums.ac.ir [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of RadiotherapyOncology, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Nedaie, Hasan A. [Department of RadiotherapyOncology, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ay, Mohammadreza [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Research Center for Science and Technology in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shirazi, Alireza; Yarahmadi, Mehran [Department of Medical Physics and Biomedical Engineering, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2013-07-01

    The electron benefit transfer (EBT) GAFCHROMIC films possess a number of features making them appropriate for high-quality dosimetry in intensity-modulated radiation therapy (IMRT). Compensators to deliver IMRT are known to change the beam-energy spectrum as well as to produce scattered photons and to contaminate electrons; therefore, the accuracy and validity of EBT-film dosimetry in compensator-based IMRT should be investigated. Percentage-depth doses and lateral-beam profiles were measured using EBT films in perpendicular orientation with respect to 6 and 18 MV photon beam energies for: (1) different thicknesses of cerrobend slab (open, 1.0, 2.0, 4.0, and 6.0 cm), field sizes (55, 1010, and 2020 cm{sup 2}), and measurement depths (D{sub max}, 5.0 and 10.0 cm); and (2) step-wedged compensator in a solid phantom. To verify results, same measurements were implemented using a 0.125 cm{sup 3} ionization chamber in a water phantom and also in Monte Carlo simulations using the Monte Carlo N-particle radiation transport computer code. The mean energy of photons was increased due to beam hardening in comparison with open fields at both 6 and 18 MV energies. For a 2020 cm{sup 2} field size of a 6 MV photon beam and a 6.0 cm thick block, the surface dose decreased by about 12% and percentage-depth doses increased up to 3% at 30.0 cm depth, due to the beam-hardening effect induced by the block. In contrast, at 18 MV, the surface dose increased by about 8% and depth dose reduced by 3% at 30.0 cm depth. The penumbral widths (80% to 20%) increase with block thickness, field size, and beam energy. The EBT film results were in good agreement with the ionization chamber dose profiles and Monte Carlo N-particle radiation transport computer code simulation behind the step-wedged compensator. Also, there was a good agreement between the EBT-film and the treatment-planning results on the anthropomorphic phantom. The EBT films can be accurately used as a 2D dosimeter for dose

  3. Effect of RF Gradient upon the Performance of the Wisconsin SRF Electron Gun

    SciTech Connect (OSTI)

    Bosch, Robert; Legg, Robert A.

    2013-12-01

    The performance of the Wisconsin 200-MHz SRF electron gun is simulated for several values of the RF gradient. Bunches with charge of 200 pC are modeled for the case where emittance compensation is completed during post-acceleration to 85 MeV in a TESLA module. We first perform simulations in which the initial bunch radius is optimal for the design gradient of 41 MV/m. We then optimize the radius as a function of RF gradient to improve the performance for low gradients.

  4. Max Tech and Beyond: High-Intensity Discharge Lamps

    SciTech Connect (OSTI)

    Scholand, Michael

    2012-04-01

    High-intensity discharge (HID) lamps are most often found in industrial and commercial applications, and are the light source of choice in street and area lighting, and sports stadium illumination. HID lamps are produced in three types - mercury vapor (MV), high pressure sodium (HPS) and metal halide (MH). Of these, MV and MH are considered white-light sources (although the MV exhibits poor color rendering) and HPS produces a yellow-orange color light. A fourth lamp, low-pressure sodium (LPS), is not a HID lamp by definition, but it is used in similar applications and thus is often grouped with HID lamps. With the notable exception of MV which is comparatively inefficient and in decline in the US from both a sales and installed stock point of view; HPS, LPS and MH all have efficacies over 100 lumens per watt. The figure below presents the efficacy trends over time for commercially available HID lamps and LPS, starting with MV and LPS in 1930's followed by the development of HPS and MH in the 1960's. In HID lamps, light is generated by creating an electric arc between two electrodes in an arc tube. The particles in the arc are partially ionized, making them electrically conductive, and a light-emitting 'plasma' is created. This arc occurs within the arc tube, which for most HID lamps is enclosed within an evacuated outer bulb that thermally isolates and protects the hot arc tube from the surroundings. Unlike a fluorescent lamp that produces visible light through down-converting UV light with phosphors, the arc itself is the light source in an HID lamp, emitting visible radiation that is characteristic of the elements present in the plasma. Thus, the mixture of elements included in the arc tube is one critical factor determining the quality of the light emitted from the lamp, including its correlated color temperature (CCT) and color rendering index (CRI). Similar to fluorescent lamps, HID lamps require a ballast to start and maintain stable operating conditions, and

  5. Experimental and simulational result multipactors in 112 MHz QWR injector

    SciTech Connect (OSTI)

    Xin, T.; Ben-Zvi, I.; Belomestnykh, S.; Brutus, J. C.; Skaritka, J.; Wu, Q.; Xiao, B.

    2015-05-03

    The first RF commissioning of 112 MHz QWR superconducting electron gun was done in late 2014. The coaxial Fundamental Power Coupler (FPC) and Cathode Stalk (stalk) were installed and tested for the first time. During this experiment, we observed several multipacting barriers at different gun voltage levels. The simulation work was done within the same range. The comparison between the experimental observation and the simulation results are presented in this paper. The observations during the test are consisted with the simulation predictions. We were able to overcome most of the multipacting barriers and reach 1.8 MV gun voltage under pulsed mode after several round of conditioning processes.

  6. High-field half-cycle terahertz radiation from relativistic laser interaction with thin solid targets

    SciTech Connect (OSTI)

    Ding, W. J.; Koh, W. S. [A-STAR Institute of High Performance Computing, Singapore 138632 (Singapore)] [A-STAR Institute of High Performance Computing, Singapore 138632 (Singapore); Sheng, Z. M. [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China) [Key Laboratory for Laser Plasmas (MoE) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2013-11-11

    It is found that half-cycle terahertz (THz) pulses with the peak field over 100 MV/cm can be produced in ultrashort intense laser interactions with thin solid targets. These THz pulses are shown to emit from both the front and rear sides of the solid target and are attributed to the coherent transition radiation by laser-produced ultrashort fast electron bunches. After the primary THz pulses, subsequent secondary half-cycle pulses are generated while some refluxing electrons cross the vacuum-target interfaces. Since such strong THz radiation is well synchronized with the driving lasers, it is particularly suitable for applications in various pump-probe experiments.

  7. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Statistical Estimation of the Atmospheric Aerosol Absorption Coefficient Based on the Data of Optical Measurements V.N. Uzhegov, V.S. Kozlov, M.V. Panchenko, Yu.A.Pkhalagov, V.V. Pol'kin, S.A. Terpugova, V.P. Shmargunov, and E.P. Yausheva Institute of Atmospheric Optics, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia Introduction The problem with the aerosol optical constants and, in particular, the imaginary part of the refractive index of particles in the visible and

  8. 1

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Comparison of the Data of Airborne, Lidar, and Photometric Sensing of Aerosol Parameters in the Cloudless Atmosphere M.V. Panchenko, V.S. Kozlov, Yu.S. Balin, S.M. Sakerin, G.P. Kokhanenko, L.E. Penner, D.M. Kabanov, E.V. Makienko, S.A. Terpugova, S.A. Turchinovich, and V.P. Shmargunov Institute of Atmospheric Optics SB RAS Tomsk, Russia Introduction A comprehensive investigation of the optical and microphysical parameters of tropospheric aerosol dictates the necessity of applying several

  9. 1.TIF

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    -one unit, therefore, it has been broken down into sections. EDMC#: r1i 11i 1 SECTION: 5 OF 11 DOCUMENT #: DOE/EIS-0113 TITLE: Final EIS Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes C^^3 DOEIEIS-0113 VOLUME VOLUME 3of5 APPENDICES M-V FINAL ENVIRONMENTAL IMPACT STATEMENT DISPOSAL OF HANFORD DEFENSE HIGH-LEVEL, TRANSURANIC AND TANK WASTES Hanford Si te Richland, Washington DECEMBER 1987. U.S. DEPARTMENT OF ENERGY PLEASE RETURN TO: ENVIRONMENTAL DIVISION RESOURCE CENTER This

  10. Liquid Argon Dielectric Strength Measurements Sarah Lockwitz

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Argon Dielectric Strength Measurements Sarah Lockwitz Fermilab LArTPC R&D Workshop July, 9 2014 Fermilab LAr Dielectric Strength July 9, 2014 S. Lockwitz et al. Recent Interest in LAr High Voltage (HV) 2 Experiment Voltage ICARUS 75 kV Darkside 50 60 kV MicroBooNE 128 kV CAPTAIN 50 kV LBNE 170 kV GLACIER 1-2 MV LAr Dielectric Strength July 9, 2014 S. Lockwitz et al. Recent Interest in LAr High Voltage (HV) * Noble liquids are becoming a popular detector medium 2 Experiment Voltage ICARUS 75

  11. Determining the release of radionuclides from tank waste residual solids. FY2015 report

    SciTech Connect (OSTI)

    King, William D.; Hobbs, David T.

    2015-09-11

    Methodology development for pore water leaching studies has been continued to support Savannah River Site High Level Waste tank closure efforts. For FY2015, the primary goal of this testing was the achievement of target pH and Eh values for pore water solutions representative of local groundwater in the presence of grout or grout-representative (CaCO3 or FeS) solids as well as waste surrogate solids representative of residual solids expected to be present in a closed tank. For oxidizing conditions representative of a closed tank after aging, a focus was placed on using solid phases believed to be controlling pH and Eh at equilibrium conditions. For three pore water conditions (shown below), the target pH values were achieved to within 0.5 pH units. Tank 18 residual surrogate solids leaching studies were conducted over an Eh range of approximately 630 mV. Significantly higher Eh values were achieved for the oxidizing conditions (ORII and ORIII) than were previously observed. For the ORII condition, the target Eh value was nearly achieved (within 50 mV). However, Eh values observed for the ORIII condition were approximately 160 mV less positive than the target. Eh values observed for the RRII condition were approximately 370 mV less negative than the target. Achievement of more positive and more negative Eh values is believed to require the addition of non-representative oxidants and reductants, respectively. Plutonium and uranium concentrations measured during Tank 18 residual surrogate solids leaching studies under these conditions (shown below) followed the general trends predicted for plutonium and uranium oxide phases, assuming equilibrium with dissolved oxygen. The highest plutonium and uranium concentrations were observed for the ORIII condition and the lowest concentrations were observed for the RRII condition. Based on these results, it is recommended that these test methodologies be used to

  12. Triangle Universities Nuclear Laboratory : 2011

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Tandem Schedule| Tandem Log Sheet| Tandem Training| Tandem SOP| RadSafe Logs| Tandem Accelerator Bay The main accelerator is a FN tandem Van de Graaff accelerator that has a maximum terminal voltage of 10 MV. Negative ions can be injected into the tandem from three sources: (1) a direct extraction negative ion source provides pulsed or dc beams of unpolarized H- and D- ions, (2) an atomic beam polarized ion source provides dc beams of polarized H- and D- ions, and (3) a heavy-ion source provides

  13. 1.TIF

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    -one unit, therefore, it has been broken down into sections. EDMC#: r1i 11i 1 SECTION: 5 OF 11 DOCUMENT #: DOE/EIS-0113 TITLE: Final EIS Disposal of Hanford Defense High-Level, Transuranic and Tank Wastes C^^3 DOEIEIS-0113 VOLUME VOLUME 3of5 APPENDICES M-V FINAL ENVIRONMENTAL IMPACT STATEMENT DISPOSAL OF HANFORD DEFENSE HIGH-LEVEL, TRANSURANIC AND TANK WASTES Hanford Si te Richland, Washington DECEMBER 1987. U.S. DEPARTMENT OF ENERGY PLEASE RETURN TO: ENVIRONMENTAL DIVISION RESOURCE CENTER This

  14. Large voltage modulation in magnetic field sensors from two-dimensional arrays of Y-Ba-Cu-O nano Josephson junctions

    SciTech Connect (OSTI)

    Cybart, Shane A. Dynes, R. C.; Cho, E. Y.; Wong, T. J.; Glyantsev, V. N.; Huh, J. U.; Yung, C. S.; Moeckly, B. H.; Beeman, J. W.; Ulin-Avila, E.; Wu, S. M.

    2014-02-10

    We have fabricated and tested two-dimensional arrays of YBa{sub 2}Cu{sub 3}O{sub 7??} superconducting quantum interference devices. The arrays contain over 36?000 nano Josephson junctions fabricated from ion irradiation of YBa{sub 2}Cu{sub 3}O{sub 7??} through narrow slits in a resist-mask that was patterned with electron beam lithography and reactive ion etching. Measurements of current-biased arrays in magnetic field exhibit large voltage modulations as high as 30?mV.

  15. BNl 703 MHz superconducting RF cavity testing

    SciTech Connect (OSTI)

    Sheehy, B.; Altinbas, Z.; Burrill, A.; Ben-Zvi, I.; Gassner, D.; Hahn, H.; Hammons, L.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Laloudakis, N.; Lederle, D.; Litvinenko, V.; McIntyre, G.; Pate, D.; Phillips, D.; Schultheiss, C.; Seda,T.; Than, R.; Xu, W.; Zaltsman, A.; Schultheiss, T.

    2011-03-28

    The BNL 5-cell, 703 MHz superconducting accelerating cavity has been installed in the high-current ERL experiment. This experiment will function as a proving ground for the development of high-current machines in general and is particularly targeted at beam development for an electron-ion collider (eRHIC). The cavity performed well in vertical tests, demonstrating gradients of 20 MV/m and a Q{sub 0} of 1e10. Here we will present its performance in the horizontal tests, and discuss technical issues involved in its implementation in the ERL.

  16. SU-E-T-52: Beam Data Comparison for 20 Linear Accelerators in One Network

    SciTech Connect (OSTI)

    LoSasso, T; Lim, S; Tang, G; Chan, M; Li, J; Obcemea, C; Song, Y; Ma, R; Yang, G; Xiong, W; Huang, D; Burman, C; Mechalakos, J; Hunt, M

    2014-06-01

    Purpose: To compare photon beam data for the 20 Varian linear accelerators (TrueBeam, iX, and EX models) in use at five centers in the same network with the intent to model with one set of beam data in Eclipsec. Methods: Varian linear accelerators, TrueBeam (3), 21 EX, iX, and Trilogy (14), and 6 EX (3), installed between 1999 and 2014 have their 6 MV and 15 MV x-ray beams reevaluated. Full commissioning, including output factors (St), percent depth doses (PDD), and off-axis profiles, was recently performed for a TrueBeam with a cc04 ion chamber in an IBA Blue phantom. Similarly, a subset of beam data for each of the other accelerators was measured recently as follows: for 33, 1010, and 3030 cm{sup 2} field sizes, flatness and penumbra (8020%) were measured at dmax and 10 cm depths, PDD were measured at 10 and 20 cm depths, and St were measured at 5 cm depth. Measurement results for all machines were compared. Results: For 15 high-energy (6 and 15 MV) and 3 low-energy machines (6MV only): 1) PDD agreed within 1.4% at 10 and 20 cm depths; 2) penumbra agreed within 1.0 mm at dmax and 10 cm depths; 3) flatness was within 1.3% at dmax and 10 cm depths; and 4) with exception of the three low energy machines, output factors were within 1.1% and 0.5% for 33 and 3030 cm{sup 2}, respectively. Measurement uncertainty, not quantified here, accounts for some of these differences. Conclusion: Measured beam data from 15 high-energy Varian linacs are consistent enough that they can be classified using one beam data set in Eclipse. Two additional high-energy machines are removed from this group until their data are further confirmed. Three low-energy machines will be in a separate class based upon differences in output factors (St)

  17. First Beam and High-Gradient Cryomodule Commissioning Results of the Advanced Superconducting Test Accelerator at Fermilab

    SciTech Connect (OSTI)

    Crawford, Darren; et al.

    2015-06-01

    The advanced superconducting test accelerator at Fermilab has accelerated electrons to 20 MeV and, separately, the International Linear Collider (ILC) style 8-cavity cryomodule has achieved the ILC performance milestone of 31.5 MV/m per cavity. When fully completed, the accelerator will consist of a photoinjector, one ILC-type cryomodule, multiple accelerator R&D beamlines, and a downstream beamline to inject 300 MeV electrons into the Integrable Optics Test Accelerator (IOTA). We report on the results of first beam, the achievement of our cryomodule to ILC gradient specifications, and near-term future plans for the facility.

  18. SU-D-207-05: Real-Time Intrafractional Motion Tracking During VMAT Delivery Using a Conventional Elekta CBCT System

    SciTech Connect (OSTI)

    Park, Yang-Kyun; Sharp, Gregory C.; Gierga, David P.; Winey, Brian A.; Ye, Sung-Joon

    2015-06-15

    Purpose: Real-time kV projection streaming capability has become recently available for Elekta XVI version 5.0. This study aims to investigate the feasibility and accuracy of real-time fiducial marker tracking during CBCT acquisition with or without simultaneous VMAT delivery using a conventional Elekta linear accelerator. Methods: A client computer was connected to an on-board kV imaging system computer, and receives and processes projection images immediately after image acquisition. In-house marker tracking software based on FFT normalized cross-correlation was developed and installed in the client computer. Three gold fiducial markers with 3 mm length were implanted in a pelvis-shaped phantom with 36 cm width. The phantom was placed on a programmable motion platform oscillating in anterior-posterior and superior-inferior directions simultaneously. The marker motion was tracked in real-time for (1) a kV-only CBCT scan with treatment beam off and (2) a kV CBCT scan during a 6-MV VMAT delivery. The exposure parameters per projection were 120 kVp and 1.6 mAs. Tracking accuracy was assessed by comparing superior-inferior positions between the programmed and tracked trajectories. Results: The projection images were successfully transferred to the client computer at a frequency of about 5 Hz. In the kV-only scan, highly accurate marker tracking was achieved over the entire range of cone-beam projection angles (detection rate / tracking error were 100.0% / 0.6±0.5 mm). In the kV-VMAT scan, MV-scatter degraded image quality, particularly for lateral projections passing through the thickest part of the phantom (kV source angle ranging 70°-110° and 250°-290°), resulting in a reduced detection rate (90.5%). If the lateral projections are excluded, tracking performance was comparable to the kV-only case (detection rate / tracking error were 100.0% / 0.8±0.5 mm). Conclusion: Our phantom study demonstrated a promising Result for real-time motion tracking using a

  19. Energy Savings Performance Contract (ESPC) ENABLE Program

    SciTech Connect (OSTI)

    2012-06-01

    The Energy Savings Performance Contract (ESPC) ENABLE program, a new project funding approach, allows small Federal facilities to realize energy and water savings in six months or less. ESPC ENABLE provides a standardized and streamlined process to install targeted energy conservation measures (ECMs) such as lighting, water, and controls with measurement and verification (M&V) appropriate for the size and scope of the project. This allows Federal facilities smaller than 200,000 square feet to make progress towards important energy efficiency and water conservation requirements.

  20. Temperature dependent photoluminescence and micromapping of multiple stacks InAs quantum dots

    SciTech Connect (OSTI)

    Xu, Ming Jaffré, Alexandre Alvarez, José Kleider, Jean-Paul Boutchich, Mohamed; Jittrong, Apichat; Chokamnuai, Thitipong; Panyakeow, Somsak; Kanjanachuchai, Songphol

    2015-02-27

    We utilized temperature dependent photoluminescence (PL) techniques to investigate 1, 3 and 5 stack InGaAs quantum dots (QDs) grown on cross-hatch patterns. PL mapping can well reproduce the QDs distribution as AFM and position dependency of QD growth. It is possible to observe crystallographic dependent PL. The temperature dependent spectra exhibit the QDs energy distribution which reflects the size and shape. The inter-dot carrier coupling effect is observed and translated as a red shift of 120mV on the [1–10] direction peak is observed at 30K on 1 stack with regards to 3 stacks samples, which is assigned to lateral coupling.

  1. Selective niobium anodization process for fabricating Josephson tunnel junctions

    SciTech Connect (OSTI)

    Kroger, H.; Smith, L.N.; Jillie, D.W.

    1981-08-01

    A novel process for fabricating refractory sperconducting tunnel junctions is described, which is useful with both deposited and native oxide barriers. The distinguishing feature of the method is that the entire superconductor-barrier-superconductor sandwich is formed before the patterning of any layer. Isolated Josephson junctions are then formed by anodizing through the upper electrode, while the devices themselves are protected by a photoresist mask. Using this process, Nb-Si:H-Nb junctions have been fabricated, whose product of critical current and subgap resistance exceeds 10 mV and whose critical current density varies by about 50% over a 2-in. diameter wafer.

  2. Detailed high-accuracy megavoltage transmission measurements: A sensitive experimental benchmark of EGSnrc

    SciTech Connect (OSTI)

    Ali, E. S. M.; McEwen, M. R.; Rogers, D. W. O.

    2012-10-15

    Purpose: There are three goals for this study: (a) to perform detailed megavoltage transmission measurements in order to identify the factors that affect the measurement accuracy, (b) to use the measured data as a benchmark for the EGSnrc system in order to identify the computational limiting factors, and (c) to provide data for others to benchmark Monte Carlo codes. Methods: Transmission measurements are performed at the National Research Council Canada on a research linac whose incident electron parameters are independently known. Automated transmission measurements are made on-axis, down to a transmission value of {approx}1.7%, for eight beams between 10 MV (the lowest stable MV beam on the linac) and 30 MV, using fully stopping Be, Al, and Pb bremsstrahlung targets and no fattening filters. To diversify energy differentiation, data are acquired for each beam using low-Z and high-Z attenuators (C and Pb) and Farmer chambers with low-Z and high-Z buildup caps. Experimental corrections are applied for beam drifts (2%), polarity (2.5% typical maximum, 6% extreme), ion recombination (0.2%), leakage (0.3%), and room scatter (0.8%)-the values in parentheses are the largest corrections applied. The experimental setup and the detectors are modeled using EGSnrc, with the newly added photonuclear attenuation included (up to a 5.6% effect). A detailed sensitivity analysis is carried out for the measured and calculated transmission data. Results: The developed experimental protocol allows for transmission measurements with 0.4% uncertainty on the smallest signals. Suggestions for accurate transmission measurements are provided. Measurements and EGSnrc calculations agree typically within 0.2% for the sensitivity of the transmission values to the detector details, to the bremsstrahlung target material, and to the incident electron energy. Direct comparison of the measured and calculated transmission data shows agreement better than 2% for C (3.4% for the 10 MV beam) and

  3. Section 58

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ' 1 3 km m 3km 0 N(h)dh Session Papers 253 Figure 1. Distribution of the aerosol number density over (1) the former USSR. Results of Long-term Airborne Research of Aerosol Characteristics of the Lower Troposphere over Former Soviet Union M.V. Panchenko, V.E. Zuev, and B.D. Belan Institute of Atmospheric Optics, Tomsk, Russia Introduction Spatial Variability of Aerosol The improvement of general atmospheric circulation models is mainly determined by the quality of the block of radiation

  4. SU-E-T-119: Dosimetric and Mechanical Characteristics of Elekta Infinity LINAC with Agility MLC

    SciTech Connect (OSTI)

    Park, J; Xu, Q; Xue, J; Zhai, Y; An, L; Chen, Y

    2014-06-01

    Purpose: Elekta Infinity is the one of the latest generation LINAC with unique features. Two Infinity LINACs are recently commissioned at our institution. The dosimetric and mechanical characteristics of the machines are presented. Methods: Both Infinity LINACs with Agility MLC (160 leaves with 0.5 cm leaf width) are configured with five electron energies (6, 9, 12, 15, and 18 MeV) and two photon energies (6 and 15 MV). One machine has additional photon energy (10 MV). The commissioning was performed by following the manufacturer's specifications and AAPM TG recommendations. Beam data of both electron and photon beams are measured with scanning ion chambers and linear diode array. Machines are adjusted to have the dosimetrically equivalent characteristics. Results: The commissioning of mechanical and imaging system meets the tolerances by TG recommendations. The PDD{sub 10} of various field sizes for 6 and 15 MV shows < 0.5% difference between two machines. For each electron beams, R{sub 80} matches with < 0.4 mm difference. The symmetry and flatness agree within 0.8% and 0.9% differences for photon beams, respectively. For electron beams, the differences of the symmetry and flatness are within 1.2% and 0.8%, respectively. The mean inline penumbras for 6, 10, and 15 MV are respectively 5.10.24, 5.60.07, and 5.90.10 mm for 10x10 cm at 10 cm depth. The crossline penumbras are larger than inline penumbras by 2.2, 1.4, and 1.0 mm, respectively. The MLC transmission factor with interleaf leakage is 0.5 % for all photon energies. Conclusion: The dosimetric and mechanical characteristics of two Infinity LINACs show good agreements between them. Although the Elekta Infinity has been used in many institutions, the detailed characteristics of the machine have not been reported. This study provides invaluable information to understand the Infinity LINAC and to compare the quality of commissioning data for other LINACs.

  5. Engineering research and development for the Elise Heavy Ion Induction Accelerator

    SciTech Connect (OSTI)

    Reginato, L.; Peters, C.

    1995-08-01

    The Fusion Energy Research engineering team has been conducting Research and Development Associated with the Construction (RDAC) of the Elise accelerator since the approval of Key Decision one (KD1 is start of construction). The engineering design effort has worked in close cooperation with the physics design staff to achieve all parameters of the Elise accelerator. The design included the 2 MV injector, matching section, combiner, induction cells, electric/magnetic quadrupoles, alignment system and controls. All major designs and some hardware testing will be discussed.

  6. Highly Dispersed Alloy Cathode Catalyst for Durability

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    HIGHLY DISPERSED ALLOY CATHODE CATALYST FOR DURABILITY T. D. Jarvi UTC Power Corporation This presentation does not contain any proprietary or confidential information HIGHLY DISPERSED ALLOY CATALYST Objectives of project Characteristic DOE 2010 Target Pt group metal Total Content 0.50 g/kW rated Pt group metal Total Loading 0.30 mg PGM/cm 2 Durability with cycling <80 o C; >80 o C 5000 h; 2000 h Electrochemical Area Loss < 40 % Mass Activity at 900 mV RHE (IR-Free) 0.44 A/mg Pt

  7. SU-E-J-13: Six Degree of Freedom Image Fusion Accuracy for Cranial Target Localization On the Varian Edge Stereotactic Radiosurgery System: Comparison Between 2D/3D and KV CBCT Image Registration

    SciTech Connect (OSTI)

    Xu, H; Song, K; Chetty, I; Kim, J; Wen, N

    2015-06-15

    Purpose: To determine the 6 degree of freedom systematic deviations between 2D/3D and CBCT image registration with various imaging setups and fusion algorithms on the Varian Edge Linac. Methods: An anthropomorphic head phantom with radio opaque targets embedded was scanned with CT slice thicknesses of 0.8, 1, 2, and 3mm. The 6 DOF systematic errors were assessed by comparing 2D/3D (kV/MV with CT) with 3D/3D (CBCT with CT) image registrations with different offset positions, similarity measures, image filters, and CBCT slice thicknesses (1 and 2 mm). The 2D/3D registration accuracy of 51 fractions for 26 cranial SRS patients was also evaluated by analyzing 2D/3D pre-treatment verification taken after 3D/3D image registrations. Results: The systematic deviations of 2D/3D image registration using kV- kV, MV-kV and MV-MV image pairs were within ±0.3mm and ±0.3° for translations and rotations with 95% confidence interval (CI) for a reference CT with 0.8 mm slice thickness. No significant difference (P>0.05) on target localization was observed between 0.8mm, 1mm, and 2mm CT slice thicknesses with CBCT slice thicknesses of 1mm and 2mm. With 3mm CT slice thickness, both 2D/3D and 3D/3D registrations performed less accurately in longitudinal direction than thinner CT slice thickness (0.60±0.12mm and 0.63±0.07mm off, respectively). Using content filter and using similarity measure of pattern intensity instead of mutual information, improved the 2D/3D registration accuracy significantly (P=0.02 and P=0.01, respectively). For the patient study, means and standard deviations of residual errors were 0.09±0.32mm, −0.22±0.51mm and −0.07±0.32mm in VRT, LNG and LAT directions, respectively, and 0.12°±0.46°, −0.12°±0.39° and 0.06°±0.28° in RTN, PITCH, and ROLL directions, respectively. 95% CI of translational and rotational deviations were comparable to those in phantom study. Conclusion: 2D/3D image registration provided on the Varian Edge radiosurgery, 6 DOF

  8. Optimization of Sparse Matrix-Vector Multiplication on Emerging Multicore Platforms

    SciTech Connect (OSTI)

    Williams, Samuel; Oliker, Leonid; Vuduc, Richard; Shalf, John; Yelick, Katherine; Demmel, James

    2008-10-16

    We are witnessing a dramatic change in computer architecture due to the multicore paradigm shift, as every electronic device from cell phones to supercomputers confronts parallelism of unprecedented scale. To fully unleash the potential of these systems, the HPC community must develop multicore specific-optimization methodologies for important scientific computations. In this work, we examine sparse matrix-vector multiply (SpMV) - one of the most heavily used kernels in scientific computing - across a broad spectrum of multicore designs. Our experimental platform includes the homogeneous AMD quad-core, AMD dual-core, and Intel quad-core designs, the heterogeneous STI Cell, as well as one of the first scientific studies of the highly multithreaded Sun Victoria Falls (a Niagara2 SMP). We present several optimization strategies especially effective for the multicore environment, and demonstrate significant performance improvements compared to existing state-of-the-art serial and parallel SpMV implementations. Additionally, we present key insights into the architectural trade-offs of leading multicore design strategies, in the context of demanding memory-bound numerical algorithms.

  9. Magnetic Random Access Memory based non-volatile asynchronous Muller cell for ultra-low power autonomous applications

    SciTech Connect (OSTI)

    Di Pendina, G. E-mail: eldar.zianbetov@cea.fr Zianbetov, E. E-mail: eldar.zianbetov@cea.fr; Beigne, E. E-mail: eldar.zianbetov@cea.fr

    2015-05-07

    Micro and nano electronic integrated circuit domain is today mainly driven by the advent of the Internet of Things for which the constraints are strong, especially in terms of power consumption and autonomy, not only during the computing phases but also during the standby or idle phases. In such ultra-low power applications, the circuit has to meet new constraints mainly linked to its changing energetic environment: long idle phases, automatic wake up, data back-up when the circuit is sporadically turned off, and ultra-low voltage power supply operation. Such circuits have to be completely autonomous regarding their unstable environment, while remaining in an optimum energetic configuration. Therefore, we propose in this paper the first MRAM-based non-volatile asynchronous Muller cell. This cell has been simulated and characterized in a very advanced 28?nm CMOS fully depleted silicon-on-insulator technology, presenting good power performance results due to an extremely efficient body biasing control together with ultra-wide supply voltage range from 160?mV up to 920?mV. The leakage current can be reduced to 154?pA thanks to reverse body biasing. We also propose an efficient standard CMOS bulk version of this cell in order to be compatible with different fabrication processes.

  10. Th and U fuel photofission study by NTD for AD-MSR subcritical assembly

    SciTech Connect (OSTI)

    Sajo-Bohus, Laszlo; Greaves, Eduardo D.; Barros, Haydn; Pino, Felix; Barrera, Maria T.; Farina, Fulvio; Davila, Jesus

    2015-07-23

    During the last decade a considerable effort has been devoted for developing energy generating systems based on advanced nuclear technology within the design concepts of GEN-IV. Thorium base fuel systems such as accelerator driven nuclear reactors are one of the often mentioned attractive and affordable options. Several radiotherapy linear accelerators are on the market and due to their reliability, they could be employed as drivers for subcritical liquid fuel assemblies. Bremsstrahlung photons with energies above 5.5MeV, induce (γ,n) and (e,e’n) reactions in the W-target. Resulting gamma radiation and photo or fission neutrons may be absorbed in target materials such as thorium and uranium isotopes to induce sustained fission or nuclear transmutation in waste radioactive materials. Relevant photo driven and photo-fission reaction cross sections are important for actinides {sup 232}Th, {sup 238}U and {sup 237}Np in the radiotherapy machines energy range of 10-20 MV. In this study we employ passive nuclear track detectors (NTD) to determine fission rates and neutron production rates with the aim to establish the feasibility for gamma and photo-neutron driven subcritical assemblies. To cope with these objectives a 20 MV radiotherapy machine has been employed with a mixed fuel target. Results will support further development for a subcritical assembly employing a thorium containing liquid fuel. It is expected that acquired technological knowledge will contribute to the Venezuelan nuclear energy program.

  11. Performance status of 0.55 eV InGaAs thermophotovoltaic cells

    SciTech Connect (OSTI)

    Wojtczuk, S.; Colter, P.; Charache, G.; DePoy, D.

    1998-10-01

    Data on {approximately} 0.55 eV In{sub 0.72}Ga{sub 0.28}As cells with an average open-circuit voltage (Voc) of 298 mV (standard deviation 7 mV) at an average short-circuit current density of 1.16 A/cm{sup 2} (sdev. 0.1 A/cm{sup 2}) and an average fill-factor of 61.6% (sdev. 2.8%) is reported. The absorption coefficient of In{sub 0.72}Ga{sub 0.28}As was measured by a differential transmission technique. The authors use a numerical integration of the absorption data to determine the radiative recombination coefficient for In{sub 0.72}Ga{sub 0.28}As. Using this absorption data and simple one-dimensional analytical formula the above cells are modeled. The models show that the cells may be limited more by Auger recombination rather than Shockley-Read-Hall (SRH) recombination at dislocation centers caused by the 1.3% lattice mismatch of the cell to the host InP wafer.

  12. Edge-terminated molybdenum disulfide with a 9.4-Å interlayer spacing for electrochemical hydrogen production

    SciTech Connect (OSTI)

    Gao, Min -Rui; Chan, Maria K. Y.; Sun, Yugang

    2015-07-03

    In this study, layered molybdenum disulfide has demonstrated great promise as a low-cost alternative to platinum-based catalysts for electrochemical hydrogen production from water. Research effort on this material has focused mainly on synthesizing highly nanostructured molybdenum disulfide that allows the exposure of a large fraction of active edge sites. Here we report a promising microwave-assisted strategy for the synthesis of narrow molybdenum disulfide nanosheets with edge-terminated structure and a significantly expanded interlayer spacing, which exhibit striking kinetic metrics with onset potential of -103 mV, Tafel slope of 49 mV per decade and exchange current density of 9.62 × 10-3 mA cm-2, performing among the best of current molybdenum disulfide catalysts. Besides benefits from the edge-terminated structure, the expanded interlayer distance with modified electronic structure is also responsible for the observed catalytic improvement, which suggests a potential way to design newly advanced molybdenum disulfide catalysts through modulating the interlayer distance.

  13. Edge-terminated molybdenum disulfide with a 9.4-Å interlayer spacing for electrochemical hydrogen production

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Gao, Min -Rui; Chan, Maria K. Y.; Sun, Yugang

    2015-07-03

    In this study, layered molybdenum disulfide has demonstrated great promise as a low-cost alternative to platinum-based catalysts for electrochemical hydrogen production from water. Research effort on this material has focused mainly on synthesizing highly nanostructured molybdenum disulfide that allows the exposure of a large fraction of active edge sites. Here we report a promising microwave-assisted strategy for the synthesis of narrow molybdenum disulfide nanosheets with edge-terminated structure and a significantly expanded interlayer spacing, which exhibit striking kinetic metrics with onset potential of -103 mV, Tafel slope of 49 mV per decade and exchange current density of 9.62 × 10-3 mAmore » cm-2, performing among the best of current molybdenum disulfide catalysts. Besides benefits from the edge-terminated structure, the expanded interlayer distance with modified electronic structure is also responsible for the observed catalytic improvement, which suggests a potential way to design newly advanced molybdenum disulfide catalysts through modulating the interlayer distance.« less

  14. A highly-active and stable hydrogen evolution catalyst based on pyrite-structured cobalt phosphosulfide

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Wen; Hu, Enyuan; Jiang, Hong; Xiang, Yingjie; Weng, Zhe; Li, Min; Fan, Qi; Yu, Xiqian; Altman, Eric I.; Wang, Hailiang

    2016-02-19

    Rational design and controlled synthesis of hybrid structures comprising multiple components with distinctive functionalities are an intriguing and challenging approach to materials development for important energy applications like electrocatalytic hydrogen production, where there is a great need for cost effective, active and durable catalyst materials to replace the precious platinum. Here we report a structure design and sequential synthesis of a highly active and stable hydrogen evolution electrocatalyst material based on pyrite-structured cobalt phosphosulfide nanoparticles grown on carbon nanotubes. The three synthetic steps in turn render electrical conductivity, catalytic activity and stability to the material. The hybrid material exhibits superiormore » activity for hydrogen evolution, achieving current densities of 10 mA cm–2 and 100 mA cm–2 at overpotentials of 48 mV and 109 mV, respectively. Lastly, phosphorus substitution is crucial for the chemical stability and catalytic durability of the material, the molecular origins of which are uncovered by X-ray absorption spectroscopy and computational simulation.« less

  15. Development of Ultra High Gradient and High Q{sub 0} Superconducting Radio Frequency Cavities

    SciTech Connect (OSTI)

    Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Clemens, William A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Follkie, James E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Harris, Teena M. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kushnick, Peter W. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Machie, Danny [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Martin, Robert E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Palczewski, Ari D. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Perry, Era A. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Slack, Gary L. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Williams, R. S. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Adolphsen, C. [SLAC, Menlo Park, California, (United States); Li, Z. [SLAC, Menlo Park, California, (United States); Hao, J. K. [Peking University, Beijing (China); Li, Y. M. [Peking University, Beijing (China); Liu, K. X. [Peking University, Beijing (China)

    2013-06-01

    We report on the recent progress at Jefferson Lab in developing ultra high gradient and high Q{sub 0} superconducting radio frequency (SRF) cavities for future SRF based machines. A new 1300 MHz 9-cell prototype cavity is being fabricated. This cavity has an optimized shape in terms of the ratio of the peak surface field (both magnetic and electric) to the acceleration gradient, hence the name low surface field (LSF) shape. The goal of the effort is to demonstrate an acceleration gradient of 50 MV/m with Q{sub 0} of 10{sup 10} at 2 K in a 9-cell SRF cavity. Fine-grain niobium material is used. Conventional forming, machining and electron beam welding method are used for cavity fabrication. New techniques are adopted to ensure repeatable, accurate and inexpensive fabrication of components and the full assembly. The completed cavity is to be first mechanically polished to a mirror-finish, a newly acquired in-house capability at JLab, followed by the proven ILC-style processing recipe established already at JLab. In parallel, new single-cell cavities made from large-grain niobium material are made to further advance the cavity treatment and processing procedures, aiming for the demonstration of an acceleration gradient of 50 MV/m with Q{sub 0} of 2?10{sup 10} at 2K.

  16. Flexible Pillared Graphene-Paper Electrodes for High-Performance Electrochemical Supercapacitors

    SciTech Connect (OSTI)

    Wang, Gongkai; Sun, Xiang; Lu, Fengyuan; Sun, Hongtao; Yu, Mingpeng; Jiang, Weilin; Liu, Changsheng; Lian, Jie

    2012-02-09

    Flexible graphene paper (GP) pillared by carbon black (CB) nanoparticles using a simple vacuum filtration method is developed as a high-performance electrode material for supercapacitors. Through the introduction of CB nanoparticles as spacers, the self-restacking of graphene sheets during the filtration process is mitigated to a great extent. The pillared GP-based supercapacitors exhibit excellent electrochemical performances and cyclic stabilities compared with GP without the addition of CB nanoparticles. At a scan rate of 10 mV s?1, the specific capacitance of the pillared GP is 138 F g^?1 and 83.2 F g^?1 with negligible 3.85% and 4.35% capacitance degradation after 2000 cycles in aqueous and organic electrolytes, respectively. At an extremely fast scan rate of 500 mV s ^?1, the specific capacitance can reach 80 F g^?1 in aqueous electrolyte. No binder is needed for assembling the supercapacitor cells and the pillared GP itself may serve as a current collector due to its intrinsic high electrical conductivity. The pillared GP has great potential in the development of promising flexible and ultralight-weight supercapacitors for electrochemical energy storage.

  17. Commissioning results of Nb3Sn cavity vapor diffusion deposition system at JLab

    SciTech Connect (OSTI)

    Eremeev, Grigory; Clemens, William A.; Macha, Kurt M.; Park, HyeKyoung; Williams, R.

    2015-09-01

    Nb3Sn as a BCS superconductor with a superconducting critical temperature higher than that of niobium offers potential benefit for SRF cavities via a lower-than-niobium surface resistance at the same temperature and frequency. A Nb3Sn vapor diffusion deposition system designed for coating of 1.5 and 1.3 GHz single-cell cavities was built and commissioned at JLab. As the part of the commissioning, RF performance at 2.0 K of a single-cell 1.5 GHz CEBAF-shaped cavity was measured before and after coating in the system. Before Nb3Sn coating the cavity had a Q0 of about 1010 and was limited by the high field Q-slope at Eacc ≅ 27 MV/m. Coated cavity exhibited the superconducting transition at about 17.9 K. The low-field quality factor was about 5∙109 at 4.3 K and 7∙109 at 2.0 K decreasing with field to about 1∙109 at Eacc ≅ 8 MV/m at both temperatures. The highest field was limited by the available RF power.

  18. NBS/Los Alamos RTM. Progress report

    SciTech Connect (OSTI)

    Penner, S.; Ayres, R.L.; Cutler, R.I.; Debenham, P.H.; Lindstrom, E.R.; Mohr, D.L.; Rose, J.E.; Unterweger, M.P.; Wilson, M.A.D.; Biddle, R.

    1985-01-01

    The NBS-Los Alamos 200 MeV Racetrack Microtron (RTM) is being built under a program aimed at developing the technology needed for high-current intermediate-energy CW electron accelerators. In this report we give an overview of the present status of the project. Recent progress includes: (1) completion of testing of the 100 keV chopper-buncher system demonstrating a normalized emittance well under the design goal of 2.6 ..pi.. mm mrad at currents exceedings the design goal of 600 ..mu..A; (2) operation of the rf structures comprising the 5 MeV injector linac at power levels up to 50 kW/m, resulting in an accelerating gradient at ..beta.. = 1 of 2 MV/m (compared to a design goal of 1.5 MV/m). The measured shunt impedance is 82.5 M..cap omega../m; (3) construction and installation of the 30 ton end magnets of the RTM. Field mapping of one magnet has been completed and its uniformity exceeds the design goal of +-2 parts in 10/sup 4/; (4) performance tests (with beam) of prototype rf beam monitors which measure current, relative phase, and beam position in both transverse plants; and (5) installation and initial operation of the primary control system.

  19. Effect of voltage polarity on oxidation-reduction potential by plasma in water

    SciTech Connect (OSTI)

    Miyahara, Takashi; Oizumi, Masanobu; Nakatani, Tatsuyuki; Sato, Takehiko

    2014-04-15

    Use of plasma in water for water treatment and medical treatment is growing and raises expectations of finding advanced functions such as an increase of biological compatibility. In the present study with a focus on the variation of oxidation-reduction potential (ORP), relationships between the electrode polarities of plasma in water and the change of water quality such as conductivity, H{sub 2}O{sub 2} concentration, dissolved hydrogen concentration, pH and ORP were revealed. Similar line spectra of radiation at the electrode tip were observed for each case of positive and negative electrode polarity. The emission intensities of OH (309 nm), Hα (656 nm), and OI (777 nm) for the positive discharge were significantly higher than those for the negative one, though the energy consumption during the discharge period of both cases was nearly the same. Positive electrode polarity was found to be more suitable than negative electrode polarity for increasing dissolved hydrogen gas and hydrogen peroxide. The ORP for the positive polarity decreased from 460 to 45 mV and that for the negative polarity decreased from 460 to 183 mV, although the pH and conductivity were not significantly changed.

  20. Effect of sulfur isotopic composition of zinc and lead sulfides on the E. M. F. of electrochemical cells

    SciTech Connect (OSTI)

    Lusk, J.; Krouse, H.R.; Batts, B.D.

    1988-03-01

    A new effect is reported in which unexpectedly large voltages are produced by electrochemical cells containing sulfides at natural isotopic abundance levels. Room temperature experiments were undertaken to determine whether electrochemical cells employing silver bromide and silver beta alumina as solid electrolytes would be sufficiently sensitive to detect small variations in sulfur isotopic composition for zinc and lead sulfides. Voltages obtained for silver bromide cells tended to increase progressively over at least 20 days, and increased in a regular fashion with increasing differences in isotopic composition between charges. Voltages exceeding 150 mV were obtained for /sup delta/S/sup 3,4/ differences up to 85 per mil for zinc sulfide, but reached only about 20 mV for lead sulfide. Silver beta alumina cells with opposing zinc and lead sulfide charges yielded larger voltages and E.M.F. minimum corresponding to a +8(/plus minus/2) per mil difference. This value shows reasonable agreement with interpolated 20/degrees/C equilibrium values of between +7.5 to +9.8 obtained from the literature. Matured silver bromide cells with opposed zinc and lead sulfide charges behaved similarly but yielded lower voltages. Silver concentration cells of the opposed type are thus able to detect isotopic equilibrium and this will permit calibration of sulfur isotope thermometers down to unexpectedly low temperatures.

  1. Latest Results of ILC High-Gradient R&D 9-cell Cavities at JLAB

    SciTech Connect (OSTI)

    Rongli Geng

    2008-02-11

    It has been over a year since JLAB started processing and testing ILC 9-cell cavities in the frame work of ILC high-gradient cavity R&D, aiming at the goal of a 35 MV/m gradient at a Q #4; of 1E10 with a yield of 90%. The necessary cavity processing steps include field flatness tuning, electropolishing (EP), hydrogen out-gassing under vacuum, high-pressure water rinsing, clean room assembly, and low temperature bake. These are followed by RF test at 2 Kelvin. Ultrasonic cleaning with Micro-90, an effective post-EP rinsing recipe discovered at JLAB, is routinely used. Seven industry manufactured 9-cell TESLAshape cavities are processed and tested repeatedly. So far, 33 EP cycles are accumulated, corresponding to more than 65 hours of active EP time. An emphasis put on RF testing is to discern cavity quench characteristics, including its nature and its location. Often times, the cavity performance is limited by thermal-magnetic quench instead of field emission. The quench field in some cavities is lower than 20 MV/m and remains unchanged despite repeated EP, implying material and/or fabrication defects. The quench field in some other cavities is high but changes unpredictably after repeated EP, suggesting processing induced defects. Based on our experience and results, several areas are identified where improvement is needed to improve cavity performance as well as yield.

  2. An environmental cracking evaluation of fastener materials for seawater applications

    SciTech Connect (OSTI)

    Aylor, D.M.

    1994-12-31

    Slow strain rate tests (SSRT) were conducted on various nickel-base, titanium base, and copper-nickel (Cu-Ni) alloys in order to identify a replacement material for Alloy K-500 in seawater fastener applications. SSRT data and fracture surface analysis of the test specimens identified a susceptibility to environmental cracking in cathodically polarized environments for Alloy K-500, Alloy 625 Plus, and Alloy 625PH. Alloy 625 Plus exhibited slightly increased environmental cracking resistance-at {minus}850 mV vs. SCE over Alloy K-500 and Alloy 625PH. Ti-6Al-4V ELI, Beta C, and Beta 21S titanium displayed no susceptibility to environmental cracking in freely corroding 3.5% NaCl or cathodically polarized conditions. Precharging these titanium alloys for 8 weeks at {minus}1,250 mV vs. SCE did not adversely affect their environmental cracking resistance. The Cu-3Ni and Cu-15Ni-7Sn spray formed alloys exhibited extensive scatter and low measured maximum loads, presumably due to macroporosity present in the as-fabricated material.

  3. Characterization of Epitaxial Film Silicon Solar Cells Grown on Seeded Display Glass: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Grover, S.; Teplin, C.; Stradins, P.; LaSalvia, V.; Chuang, T. K.; Couillard, J. G.; Branz, H. M.

    2012-06-01

    We report characterizations of epitaxial film crystal silicon (c-Si) solar cells with open-circuit voltages (Voc) above 560 mV. The 2-um absorber cells are grown by low-temperature (<750 degrees C) hot-wire CVD (HWCVD) on Corning EAGLE XG display glass coated with a layer-transferred (LT) Si seed. The high Voc is a result of low-defect epitaxial Si (epi-Si) growth and effective hydrogen passivation of defects. The quality of HWCVD epitaxial growth on seeded glass substrates depends on the crystallographic quality of the seed and the morphology of the epitaxial growth surface. Heterojunction devices consist of glass/c-Si LT seed/ epi n+ Si:P/epi n- Si:P/intrinsic a-Si:H/p+ a-Si:H/ITO. Similar devices grown on electronically 'dead' n+ wafers have given Voc {approx}630 mV and {approx}8% efficiency with no light trapping features. Here we study the effects of the seed surface polish on epi-Si quality, how hydrogenation influences the device character, and the dominant junction transport physics.

  4. Internal plasma potential measurements of a Hall thruster using xenon and krypton propellant

    SciTech Connect (OSTI)

    Linnell, Jesse A.; Gallimore, Alec D.

    2006-09-15

    For krypton to become a realistic option for Hall thruster operation, it is necessary to understand the performance gap between xenon and krypton and what can be done to reduce it. A floating emissive probe is used with the Plasmadynamics and Electric Propulsion Laboratory's High-speed Axial Reciprocating Probe system to map the internal plasma potential structure of the NASA-173Mv1 Hall thruster [R. R. Hofer, R. S. Jankovsky, and A. D. Gallimore, J. Propulsion Power 22, 721 (2006); and ibid.22, 732 (2006)] using xenon and krypton propellant. Measurements are taken for both propellants at discharge voltages of 500 and 600 V. Electron temperatures and electric fields are also reported. The acceleration zone and equipotential lines are found to be strongly linked to the magnetic-field lines. The electrostatic plasma lens of the NASA-173Mv1 Hall thruster strongly focuses the xenon ions toward the center of the discharge channel, whereas the krypton ions are defocused. Krypton is also found to have a longer acceleration zone than the xenon cases. These results explain the large beam divergence observed with krypton operation. Krypton and xenon have similar maximum electron temperatures and similar lengths of the high electron temperature zone, although the high electron temperature zone is located farther downstream in the krypton case.

  5. Overview and Lessons Learned of the Jefferson Lab Cryomodule Production for the CEBAF 12 GeV Upgrade

    SciTech Connect (OSTI)

    Hogan, John P.; Burrill, Andrew B.; Drury, Michael A.; Harwood, Leigh H.; Hovater, J. Curt; Reece, Charles E.; Wiseman, Mark A.

    2013-12-01

    The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is nearing completion of an energy upgrade from 6 to 12 GeV. An integral part of the upgrade is the addition of ten new cryomodules, each consisting of eight seven-cell superconducting radio-frequency (SRF) cavities. An average performance of 100+MV of acceleration per cryomodule is needed to achieve the 12 GeV beam energy goal. The production methodology was for industry to provide and deliver the major components to Jefferson Lab, where they were tested and assembled into cryomodules. The production process begins with an inspection upon receiving of all major components followed by individual performance qualification testing. The SRF cavities received their final chemical processing and cleaning at Jefferson Lab. The qualified components along with all associated hardware and instrumentation are assembled, tested, installed into CEBAF and run through an integrated system checkout in preparation for beam operations. The production process is complete and one of the first completed cryomodules has successfully produced 108 MV of acceleration with a linac beam current of 465 {micro}A.

  6. Room-temperature amorphous alloy field-effect transistor exhibiting particle and wave electronic transport

    SciTech Connect (OSTI)

    Fukuhara, M.; Kawarada, H.

    2015-02-28

    The realization of room-temperature macroscopic field effect transistors (FETs) will lead to new epoch-making possibilities for electronic applications. The I{sub d}-V{sub g} characteristics of the millimeter-sized aluminum-oxide amorphous alloy (Ni{sub 0.36}Nb{sub 0.24}Zr{sub 0.40}){sub 90}H{sub 10} FETs were measured at a gate-drain bias voltage of 060??V in nonmagnetic conditions and under a magnetic fields at room temperature. Application of dc voltages to the gate electrode resulted in the transistor exhibiting one-electron Coulomb oscillation with a period of 0.28?mV, Fabry-Perot interference with a period of 2.35??V under nonmagnetic conditions, and a Fano effect with a period of 0.26?mV for Vg and 0.2?T under a magnetic field. The realization of a low-energy controllable device made from millimeter-sized Ni-Nb-Zr-H amorphous alloy throws new light on cluster electronics.

  7. The electrochemical performance of ordered mesoporous carbon/nickel compounds composite material for supercapacitor

    SciTech Connect (OSTI)

    Feng, Jicheng; Zhao, Jiachang; Tang, Bohejin; Liu, Ping; Xu, Jingli

    2010-12-15

    A series of high performance ordered mesoporous carbon/nickel compounds composites have been synthesized by a combination of incipient wetness impregnation and hydrothermal method for the first time. X-ray diffraction (XRD), N{sub 2} adsorption/desorption isotherms and transmission electron microscopy (TEM) are used to characterize the composites derived at the hydrothermal temperature of 125, 150, 175, 200, 250, 275 and 300 {sup o}C. The formation of nanosized nickel compounds, fully inside the mesopore system, was confirmed with XRD and TEM. An N{sub 2} adsorption/desorption isotherms measurements still revealed mesoporosity for the host/guest compounds. It is noteworthy that an OMC/nickel nitrate hydroxide hydrate composite (OMCN-150) exhibits more excellent performance. Based on the various hydrothermal temperatures of the composite, the capacitance of an OMCN-150 delivering the best electrochemical performance is about 2.4 (5 mV s{sup -1}) and 1.5 (50 mV s{sup -1}) times of the pristine OMC. The capacitance retention of an OMCN-150 is 96.1%, which indicates that the electrochemical performance of the supercapacitor is improved greatly, and represents novel research and significant advances in the field of electrode composite materials for supercapacitor. -- Graphical abstract: A series of high performance nickel compound/ordered mesoporous carbon composites were synthesized by a combination of incipient wetness impregnation and hydrothermal method for the first time. Display Omitted

  8. Vaccinia virus temperature-sensitive mutants in the A28 gene produce non-infectious virions that bind to cells but are defective in entry

    SciTech Connect (OSTI)

    Turner, Peter C. Dilling, Bradley P.; Prins, Cindy; Cresawn, Steven G.; Moyer, Richard W.; Condit, Richard C.

    2007-09-15

    The vaccinia virus temperature-sensitive mutations Cts6 and Cts9 were mapped by marker rescue and DNA sequencing to the A28 gene. Cts6 and Cts9 contain an identical 2-bp deletion truncating the A28 protein and removing the fourth conserved cysteine near the C-terminus. Cts9 mutant virions produced at 40 deg. C were non-infectious and unable to cause cytopathic effect. However, the mutant A28 protein localized to purified mature virions (MV) at 31 deg. C and 40 deg. C. MV of Cts9 produced at 40 deg. C bound to cells but did not enter cells. Low pH treatment of Cts9-infected cells at 18 h p.i. failed to produce fusion from within at 40 deg. C, but gave fusion at 31 deg. C. Adsorption of Cts9 mutant virions to cells followed by low pH treatment showed a defect in fusion from without. The Cts9 phenotype suggests that the A28 protein is involved in both virus entry and cell-cell fusion, and supports the linkage between the two processes.

  9. Niobium nitride Josephson devices with semiconductor barriers. Final report 27 May 80-25 Sep 81

    SciTech Connect (OSTI)

    Kroger, H.; Jillie, D.W.; Smith, L.N.

    1981-09-01

    Semiconductor barriers are investigated as a means of producing NbN-barrier-NbN and NbN-barrier-Nb Josephson devices. Chemical vapor deposition of silicon and germanium polycrystalline barriers onto NbN substrates and sputter deposition of amorphous silicon onto NbN substrates were used to produce the barrier layers. NbN-aSi-Nb tunnel junctions which had a Vm (product of critical current and subgap resistance) as high as 15 mV were fabricated. Phosphorus doped Ge barriers about 60 A thick produced tunnel junctions with Vm = 2-3 mV. Super Schottky diodes were produced with boron doped germanium barriers about 130 A thick. Boron doped germanium barriers about 60-70 A thick were observed to have Josephson coupling with good uniformity as judged by ideal threshold curves, but had non-ideal tunneling characteristics. NbN-Ge-NbN devices were produced by first depositing the trilayer structure over the entire wafer and then isolating the desired junctions by thermally oxidizing the upper NbN layer between devices, with the device area being protected from oxidization by a patterned SiO2 layer. Some correlation between good tunneling characteristics and the crystal structure and high optical reflectivity of the lower NbN electrode was observed.

  10. Josephson device with tunneling barrier having low density of localized states and enhanced figures of merit

    SciTech Connect (OSTI)

    Kroger, H.

    1984-12-25

    A superconducting tunnel junction device having superconductive electrodes has a non-homogeneous barrier layer of amorphous semiconductive material, wherein when the central region is deposited in the presence of a gaseous atmosphere containing hydrogen there obtains a reduced density of localized states in the central region of the barrier so as to minimize leakage currents, resulting in improved current-voltage characteristics approximating an ideal tunnel junction device. The low leakage currents improve margins of Josephson logic circuits over tunneling barriers using uniformly deposited hydrogenated silicon with niobium electrodes, and increase the sensitivity of S-I-S microwave and millimeter wave length detectors and mixers. In a preferred embodiment, superconductive electrodes of niobium are conjoined with a tri-layer barrier using pure silicon adjoining the electrodes and a core of hydrogenated amorphous silicon. V /SUB m/ parameters of merit (product of subgap resistance and critical current) as high as 28 mV at 4.2K were obtained with this embodiment, compared with 10 mV for the prior art.

  11. The use of LBB concept in French fast reactors: Application to SPX plant

    SciTech Connect (OSTI)

    Turbat, A.; Deschanels, H.; Sperandio, M.

    1997-04-01

    The leak before break (LBB) concept was not used at the design level for SUPERPHENIX (SPX), but different studies have been performed or are in progress concerning different components : Main Vessel (MV), pipings. These studies were undertaken to improve the defense in depth, an approach used in all French reactors. In a first study, the LBB approach has been applied to the MV of SPX plant to verify the absence of risk as regards the core supporting function and to help in the definition of in-service inspection (ISI) program. Defining a reference semi-elliptic defect located in the welds of the structure, it is verified that the crack growth is limited and that the end-of-life defect is smaller than the critical one. Then it is shown that the hoop welds (those which are the most important for safety) located between the roof and the triple point verify the leak-before-break criteria. However, generally speaking, the low level of membrane primary stresses which is favorable for the integrity of the vessel makes the application of the leak-before-break concept more difficult due to small crack opening areas. Finally, the extension of the methodology to the secondary pipings of SPX incorporating recent European works of DCRC is briefly presented.

  12. Microvesicles released constitutively from prostate cancer cells differ biochemically and functionally to stimulated microvesicles released through sublytic C5b-9

    SciTech Connect (OSTI)

    Stratton, Dan; Moore, Colin; Antwi-Baffour, Samuel; Lange, Sigrun; Inal, Jameel

    2015-05-08

    We have classified microvesicles into two subtypes: larger MVs released upon stimulation of prostate cancer cells, sMVs, and smaller cMVs, released constitutively. cMVs are released as part of cell metabolism and sMVs, released at 10-fold higher levels, produced upon activation, including sublytic C5b-9. From electron microscopy, nanosight tracking analysis, dynamic light scattering and flow cytometry, cMVs (194–210 nm in diameter) are smaller than sMVs (333–385 nm). Furthermore, using a Quartz Crystal Microbalance measuring changes in resonant frequency (Δf) that equate to mass deposited on a sensor, an sMV and a cMV are estimated at 0.267 and 0.241 pg, respectively. sMVs carry more calcium and protein, express higher levels of lipid rafts, GPI-anchored CD55 and phosphatidylserine including deposited C5b-9 compared to cMVs. This may allude to biological differences such as increased bound C4BP on sMVs inhibiting complement more effectively. - Highlights: • Prostate cells release microvesicles constitutively (cMVs) or upon stimulus (sMVs). • sMVs are larger than cMVs and carry more protein, lipid rafts and surface PstSer. • sMVs inhibit complement more effectively than cMVs.

  13. A high sensitivity fiber optic macro-bend based gas flow rate transducer for low flow rates: Theory, working principle, and static calibration

    SciTech Connect (OSTI)

    Schena, Emiliano; Saccomandi, Paola; Silvestri, Sergio

    2013-02-15

    A novel fiber optic macro-bend based gas flowmeter for low flow rates is presented. Theoretical analysis of the sensor working principle, design, and static calibration were performed. The measuring system consists of: an optical fiber, a light emitting diode (LED), a Quadrant position sensitive Detector (QD), and an analog electronic circuit for signal processing. The fiber tip undergoes a deflection in the flow, acting like a cantilever. The consequent displacement of light spot center is monitored by the QD generating four unbalanced photocurrents which are function of fiber tip position. The analog electronic circuit processes the photocurrents providing voltage signal proportional to light spot position. A circular target was placed on the fiber in order to increase the sensing surface. Sensor, tested in the measurement range up to 10 l min{sup -1}, shows a discrimination threshold of 2 l min{sup -1}, extremely low fluid dynamic resistance (0.17 Pa min l{sup -1}), and high sensitivity, also at low flow rates (i.e., 33 mV min l{sup -1} up to 4 l min{sup -1} and 98 mV min l{sup -1} from 4 l min{sup -1} up to 10 l min{sup -1}). Experimental results agree with the theoretical predictions. The high sensitivity, along with the reduced dimension and negligible pressure drop, makes the proposed transducer suitable for medical applications in neonatal ventilation.

  14. Corrosion, stress corrosion cracking, and electrochemistry of the iron and nickel base alloys in caustic environments

    SciTech Connect (OSTI)

    Koehler, R.; Beck, F. H.; Agrawal, A. K.; Soendjasmono, B.; Staehle, R. W.

    1980-02-01

    The electrochemical behavior of high purity (99.95% to 99.99%) iron in 0.6M NaCl and 1.0M Na/sub 2/SO/sub 4/ containing H/sub 2/S (50 ppM to 34,000 ppM) was studied using cyclic voltammetry, chronoamperometry, and slow scan rate polarization. Results have indicated that iron does undergo passivation in sulfate solutions containing H/sub 2/S. Iron dissolution depends on the presence of Cl/sup -/, the concentration of H/sub 2/S and solution pH. An equation is given that describes the anodic Tafel current densities. The slow strain rate test was used to evaluate the effect of electrode potential on the susceptibility of 2-1/4Cr, Mo steel to stress corrosion cracking in boiling 50% NaOH solution. Susceptibility decreased and general corrosion increased with increasing potentials. Failures contained a combination of ductile and brittle fracture. Time-to-failure was longest for controlled potentials of -700 and -600mV (Hg/HgO reference) in the -1100 to -400mV range used in this study.

  15. Modeling electron emission and surface effects from diamond cathodes

    SciTech Connect (OSTI)

    Dimitrov, D. A.; Smithe, D.; Cary, J. R.; Ben-Zvi, I.; Rao, T.; Smedley, J.; Wang, E.

    2015-02-05

    We developed modeling capabilities, within the Vorpal particle-in-cell code, for three-dimensional (3D) simulations of surface effects and electron emission from semiconductor photocathodes. They include calculation of emission probabilities using general, piece-wise continuous, space-time dependent surface potentials, effective mass and band bending field effects. We applied these models, in combination with previously implemented capabilities for modeling charge generation and transport in diamond, to investigate the emission dependence on applied electric field in the range from approximately 2 MV/m to 17 MV/m along the [100] direction. The simulation results were compared to experimental data. For the considered parameter regime, conservation of transverse electron momentum (in the plane of the emission surface) allows direct emission from only two (parallel to [100]) of the six equivalent lowest conduction band valleys. When the electron affinity χ is the only parameter varied in the simulations, the value χ = 0.31 eV leads to overall qualitative agreement with the probability of emission deduced from experiments. Including band bending in the simulations improves the agreement with the experimental data, particularly at low applied fields, but not significantly. In this study, using surface potentials with different profiles further allows us to investigate the emission as a function of potential barrier height, width, and vacuum level position. However, adding surface patches with different levels of hydrogenation, modeled with position-dependent electron affinity, leads to the closest agreement with the experimental data.

  16. Modeling electron emission and surface effects from diamond cathodes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dimitrov, D. A.; Smithe, D.; Cary, J. R.; Ben-Zvi, I.; Rao, T.; Smedley, J.; Wang, E.

    2015-02-05

    We developed modeling capabilities, within the Vorpal particle-in-cell code, for three-dimensional (3D) simulations of surface effects and electron emission from semiconductor photocathodes. They include calculation of emission probabilities using general, piece-wise continuous, space-time dependent surface potentials, effective mass and band bending field effects. We applied these models, in combination with previously implemented capabilities for modeling charge generation and transport in diamond, to investigate the emission dependence on applied electric field in the range from approximately 2 MV/m to 17 MV/m along the [100] direction. The simulation results were compared to experimental data. For the considered parameter regime, conservation of transversemore » electron momentum (in the plane of the emission surface) allows direct emission from only two (parallel to [100]) of the six equivalent lowest conduction band valleys. When the electron affinity χ is the only parameter varied in the simulations, the value χ = 0.31 eV leads to overall qualitative agreement with the probability of emission deduced from experiments. Including band bending in the simulations improves the agreement with the experimental data, particularly at low applied fields, but not significantly. In this study, using surface potentials with different profiles further allows us to investigate the emission as a function of potential barrier height, width, and vacuum level position. However, adding surface patches with different levels of hydrogenation, modeled with position-dependent electron affinity, leads to the closest agreement with the experimental data.« less

  17. Construction and Test of a Novel Superconducting RF Electron gun

    SciTech Connect (OSTI)

    Bisognano, Joseph J.

    2014-04-16

    The University of Wisconsin-Madison has completed installation of a superconducting electron gun. Its concept was optimized to be the source for a CW free electron laser facility with multiple megahertz repetition rate end stations. This VHF superconducting configuration holds the promise of the highest performance for CW injectors. Initial commissioning efforts show that the cavity can achieve gradients of 35 MV/m at the cathode position. With the cathode inserted CW operation has been achieved at 20 MV/m with good control of microphonics, negligible dark current, and Q0 > 3×109 at 4 K. Bunch charges of ~100 pC have been delivered, and first simple beam measurements made. These preliminary results are very encouraging for production of 100s pC bunches with millimeter-milliradian or smaller normalized emittances. Plans are in place to carry out more definitive studies to establish the full capabilities. However, since the grant was not renewed, the electron gun is currently mothballed, and without supplemental fund the opportunity for further work will be lost.

  18. The analysis of leakage current in MIS Au/SiO{sub 2}/n-GaAs at room temperature

    SciTech Connect (OSTI)

    Altuntas, H.; Ozcelik, S.

    2013-10-15

    The aim of this study is to determine the reverse-bias leakage current conduction mechanisms in Au/SiO{sub 2}/n-GaAs metal-insulator-semiconductor type Schottky contacts. Reverse-bias current-voltage measurements (I-V) were performed at room temperature. The using of leakage current values in SiO{sub 2} at electric fields of 1.46-3.53 MV/cm, ln(J/E) vs. {radical}E graph showed good linearity. Rom this plot, dielectric constant of SiO{sub 2} was calculated as 3.7 and this value is perfect agreement with 3.9 which is value of SiO{sub 2} dielectric constant. This indicates, Poole-Frenkel type emission mechanism is dominant in this field region. On the other hand, electric fields between 0.06-0.73 and 0.79-1.45 MV/cm, dominant leakage current mechanisms were found as ohmic type conduction and space charge limited conduction, respectively.

  19. LOPOS; Advanced device isolation for a 0. 8. mu. CMOS/BULK process technology

    SciTech Connect (OSTI)

    Ghezzo, M.; Kaminsky, E.; Nissan-Cohen, Y.; Frank, P.; Saia, R. . Corporate Research and Development Dept.)

    1989-07-01

    Local oxidation of polysilicon over silicon (LOPOS) isolation has been characterized for use in a 0.8 {mu}m CMOS/BULK process with reduced field oxide edge encroachment (bird's beak). Compared to the standard local oxidation of silicon (LOCOS) LOPOS adds a thin polysilicon layer between the stress relief oxide and the overlying nitride without changing the active area patterning procedure. To optimize the LOPOS structure, the thickness of the oxide and nitride layers was varied in a fully-factorial experiment, measuring the bird's beak and checking for the presence of silicon edge defects. It was found that for a 6000{Angstrom} field oxide the bird's beak can be safely reduced to {approx}0.3 {mu}m per side with LOPOS, which is significantly less than {approx}0.55 {mu}m with LOCOS. The corresponding stack consisted of 1500{Angstrom} Si{sub 3}N{sub 4}/550{Angstrom} polysilicon (undoped)/200{Angstrom} SiO{sub 2}. LOPOS fabricated diodes exhibited low leakage of {lt} 0.5 nA/cm{sup 2} and {lt} 0.5 pA/cm for the area and edge components, respectively, while MOS capacitors were breakdown-free up to 8 MV/cm during voltage-stress tests, compared to 6 MV/cm for LOCOS.

  20. Review of Prior Commercial Building Energy Efficiency Retrofit Evaluation: A Report to Snohomish Public Utilities District

    SciTech Connect (OSTI)

    Price, Phillip

    2014-12-22

    Snohomish County Public Utilities District (the District or Snohomish PUD) provides electricity to about 325,000 customers in Snohomish County, Washington. The District has an incentive programs to encourage commercial customers to improve energy efficiency: the District partially reimburses the cost of approved retrofits if they provide a level of energy performance improvement that is specified by contract. In 2013 the District contracted with Lawrence Berkeley National Laboratory to provide a third-party review of the Monitoring and Verification (M&V) practices the District uses to evaluate whether companies are meeting their contractual obligations. This work helps LBNL understand the challenges faced by real-world practitioners of M&V of energy savings, and builds on a body of related work such as Price et al. (2013). The District selected a typical project for which they had already performed an evaluation. The present report includes the District's original evaluation as well as LBNL's review of their approach. The review is based on the document itself; on investigation of the load data and outdoor air temperature data from the building evaluated in the document; and on phone discussions with Bill Harris of the Snohomish County Public Utilities District. We will call the building studied in the document the subject building, the original Snohomish PUD report will be referred to as the Evaluation, and this discussion by LBNL is called the Review.

  1. ULTRA-COMPACT ACCELERATOR TECHNOLOGIES FOR APPLICATION IN NUCLEAR TECHNIQUES

    SciTech Connect (OSTI)

    Sampayan, S; Caporaso, G; Chen, Y; Carazo, V; Falabella, S; Guethlein, G; Guse, S; Harris, J R; Hawkins, S; Holmes, C; Krogh, M; Nelson, S; Paul, A C; Pearson, D; Poole, B; Schmidt, R; Sanders, D; Selenes, K; Sitaraman, S; Sullivan, J; Wang, L; Watson, J

    2009-06-11

    We report on compact accelerator technology development for potential use as a pulsed neutron source quantitative post verifier. The technology is derived from our on-going compact accelerator technology development program for radiography under the US Department of Energy and for a clinic sized compact proton therapy systems under an industry sponsored Cooperative Research and Development Agreement. The accelerator technique relies on the synchronous discharge of a prompt pulse generating stacked transmission line structure with the beam transit. The goal of this technology is to achieve {approx}10 MV/m gradients for 10s of nanoseconds pulses and to {approx}100 MV/m gradients for {approx}1 ns systems. As a post verifier for supplementing existing x-ray equipment, this system can remain in a charged, stand-by state with little or no energy consumption. We detail the progress of our overall component development effort with the multilayer dielectric wall insulators (i.e., the accelerator wall), compact power supply technology, kHz repetition-rate surface flashover ion sources, and the prompt pulse generation system consisting of wide-bandgap switches and high performance dielectric materials.

  2. Rheology and microstructure of concentrated zirconia-alumina suspensions for gelcasting composites

    SciTech Connect (OSTI)

    Bleier, A.; Omatete, O.O.

    1992-12-31

    The relations among colloidal stability, suspension rheology, and solids loading are elucidated for zirconia-alumina mixtures containing 20 volt ZrO{sub 2}, based on solids. The lower colloidal stability of ZrO{sub 2} limits the rheological properties of this system. If the zeta potential of ZrO{sub 2} is less than 49 mV, high degrees of pseudoplasticity, high yield stress, high viscosity, and long relaxation times characterize the binary suspensions. These effects occur, despite the fact that ZrO{sub 2} is the minor ceramic constituent. If the zeta potential of ZrO{sub 2} is maintained above 49 mV, suspensions with high solids loading (55 vol%) can be prepared which behave as Newtonian fluids over the 0-to-200 s-1 shear rate range and as an elastic solid at higher rates. As the solids loading of a highly stable binary suspension is increased, the rheological properties change. They evolve from those of a near Newtonian-like fluid with nearly independent particles (40 vol%) to those of a pseudoplastic fluid with a weakly interacting particle network (50 vol%) to those of an elastic-like solid composed of crowded, strongly repulsive particles (55 vol%). Low-shear conditions for suspension-transport and mold-filling operations that ensure a homogeneous arrangement of ZrO{sub 2} and Al{sub 2}O{sub 3} particles in a gelcast ceramic seem promising.

  3. Development of a one-stop beam verification system using electronic portal imaging devices for routine quality assurance

    SciTech Connect (OSTI)

    Lim, Sangwook; Ma, Sun Young; Jeung, Tae Sig; Yi, Byong Yong; Lee, Sang Hoon; Lee, Suk; Cho, Sam Ju; Choi, Jinho

    2012-10-01

    In this study, a computer-based system for routine quality assurance (QA) of a linear accelerator (linac) was developed by using the dosimetric properties of an amorphous silicon electronic portal imaging device (EPID). An acrylic template phantom was designed such that it could be placed on the EPID and be aligned with the light field of the collimator. After irradiation, portal images obtained from the EPID were transferred in DICOM format to a computer and analyzed using a program we developed. The symmetry, flatness, field size, and congruence of the light and radiation fields of the photon beams from the linac were verified simultaneously. To validate the QA system, the ion chamber and film (X-Omat V2; Kodak, New York, NY) measurements were compared with the EPID measurements obtained in this study. The EPID measurements agreed with the film measurements. Parameters for beams with energies of 6 MV and 15 MV were obtained daily for 1 month using this system. It was found that our QA tool using EPID could substitute for the film test, which is a time-consuming method for routine QA assessment.

  4. Measuring linac photon beam energy through EPID image analysis of physically wedged fields

    SciTech Connect (OSTI)

    Dawoud, S. M. Weston, S. J.; Bond, I.; Ward, G. C.; Rixham, P. A.; Mason, J.; Huckle, A.; Sykes, J. R.

    2014-02-15

    Purpose: Electronic portal imaging devices (EPIDs) have proven to be useful tools for measuring several parameters of interest in linac quality assurance (QA). However, a method for measuring linac photon beam energy using EPIDs has not previously been reported. In this report, such a method is devised and tested, based on fitting a second order polynomial to the profiles of physically wedged beams, where the metric of interest is the second order coefficientα. The relationship between α and the beam quality index [percentage depth dose at 10 cm depth (PDD{sub 10})] is examined to produce a suitable calibration curve between these two parameters. Methods: Measurements were taken in a water-tank for beams with a range of energies representative of the local QA tolerances about the nominal value 6 MV. In each case, the beam quality was found in terms of PDD{sub 10} for 100 × 100 mm{sup 2} square fields. EPID images of 200 × 200 mm{sup 2} wedged fields were then taken for each beam and the wedge profile was fitted in MATLAB 2010b (The MathWorks, Inc., Natick, MA). α was then plotted against PDD{sub 10} and fitted with a linear relation to produce the calibration curve. The uncertainty in α was evaluated by taking five repeat EPID images of the wedged field for a beam of 6 MV nominal energy. The consistency of measuring α was found by taking repeat measurements on a single linac over a three month period. The method was also tested at 10 MV by repeating the water-tank crosscalibration for a range of energies centered approximately about a 10 MV nominal value. Finally, the calibration curve from the test linac and that from a separate clinical machine were compared to test consistency of the method across machines in a matched fleet. Results: The relationship betweenα and PDD{sub 10} was found to be strongly linear (R{sup 2} = 0.979) while the uncertainty in α was found to be negligible compared to that associated with measuring PDD{sub 10} in the water-tank (

  5. Development of a CW Superconducting RF Booster Cryomodule for Future Light Sources

    SciTech Connect (OSTI)

    Grimm, Terry L; Bogle, Andrew; Deimling, Brian; Hollister, Jerry; II, Randall Jecks; Kolka, Ahren; Romel, Chandra

    2009-04-13

    Future light sources based on seeded free electron lasers (FEL) have the potential to increase the soft xray flux by several orders of magnitude with short bunch lengths to probe electron structure and dynamics. A low emittance, high rep-rate radio frequency (RF) photocathode electron gun will generate the electron beam that will require very stringent beam control and manipulation through the superconducting linear accelerator to maintain the high brightness required for an x-ray FEL. The initial or booster cavities of the superconducting radio frequency (SRF) linear accelerator will require stringent control of transverse kicks and higher order modes (HOM) during the beam manipulation and conditioning that is needed for emittance exchange and bunch compression. This SBIR proposal will develop, fabricate and test a continuous-wave SRF booster cryomodule specifically for this application. Phase I demonstrated the technical feasibility of the project by completing the preliminary SRF cavity and cryomodule design and its integration into an R&D test stand for beam studies at Lawrence Berkeley National Laboratory (LBNL). The five-cell bulk niobium cavities operate at 750 MHz, and generate 10 MV each with strong HOM damping and special care to eliminate transverse kicks due to couplers. Due to continuous-wave operation at fairly modest beam currents and accelerating gradients the complexity of the two cavity cryomodule is greatly reduced compared to an ILC type system. Phase II will finalize the design, and fabricate and test the booster cryomodule. The cryomodule consists of two five-cell cavities that will accelerate megahertz bunch trains with nano-coulomb charge. The accelerating gradient is a very modest 10 MV/m with peak surface fields of 20 MV/m and 42.6 mT. The cryogenic system operates at 2 K with a design dynamic load of 20 W and total required cryogenic capacity of 45 W. The average beam current of up to 1 mA corresponds to a beam power of 10 kW per 5- cell

  6. Experimental study of self magnetic pinch diode as flash radiography source at 4 megavolt

    SciTech Connect (OSTI)

    Etchessahar, Bertrand; Bicrel, Béatrice; Cassany, Bruno; Desanlis, Thierry; Voisin, Luc; Maisonny, Rémi; Toury, Martial; Hourdin, Laurent; Cartier, Frédéric; Cartier, Stéphanie; D'Almeida, Thierry; Delbos, Christophe; Garrigues, Alain; Plouhinec, Damien; Ritter, Sandra; Sol, David; Zucchini, Frédéric; Caron, Michel

    2013-10-15

    The Self Magnetic Pinch (SMP) diode is a potential high-brightness X-ray source for high voltage generators (2–10 MV) that has shown good reliability for flash radiography applications [D. D. Hinchelwood et al., “High power self-pinch diode experiments for radiographic applications” IEEE Trans. Plasma Sci. 35(3), 565–572 (2007)]. We have studied this diode at about 4 MV, driven by the ASTERIX generator operated at the CEA/GRAMAT [G. Raboisson et al., “ASTERIX, a high intensity X-ray generator,” in Proceedings of the 7th IEEE Pulsed Power Conference (1989), pp. 567–570]. This generator, made up of a capacitor bank and a Blumlein line, was initially designed to test the behavior of electronic devices under irradiation. In our experiments, the vacuum diode is modified in order to set up flash radiographic diodes. A previous set of radiographic experiments was carried out on ASTERIX with a Negative Polarity Rod Pinch (NPRP) diode [B. Etchessahar et al., “Study and optimization of negative polarity rod pinch diode as flash radiography source at 4.5 MV,” Phys. Plasmas 19(9), 093104 (2012)]. The SMP diode which is examined in the present study provides an alternative operating point on the same generator and a different radiographic performance: 142 ± 11 rad at 1 m dose (Al) for a 3.46 ± 0.42 mm spot size (1.4× FWHM of the LSF). This performance is obtained in a reproducible and robust nominal configuration. However, several parametric variations were also tested, such as cathode diameter and anode/cathode gap. They showed that an even better performance is accessible after optimization, in particular, a smaller spot size (<3 mm). Numbers of electrical, optical, and X-ray diagnostics have been implemented in order to gain more insight in the diode physics and to optimize it further. For the first time in France, visible and laser imaging of the SMP diode has been realized, from a radial point of view, thus, providing key information on the electrode

  7. Comparison of single junction AlGaInP and GaInP solar cells grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Masuda, T; Tomasulo, S; Lang, JR; Lee, ML

    2015-03-07

    We have investigated similar to 2.0 eV (AlxGa1-x)(0.51)In0.49P and similar to 1.9 eV Ga0.51In0.49P single junction solar cells grown on both on-axis and misoriented GaAs substrates by molecular beam epitaxy (MBE). Although lattice-matched (AlxGa1-x)(0.51)In0.49P solar cells are highly attractive for space and concentrator photovoltaics, there have been few reports on the MBE growth of such cells. In this work, we demonstrate open circuit voltages (V-oc) ranging from 1.29 to 1.30 V for Ga0.51In0.49P cells, and 1.35-1.37 V for (AlxGa1-x)(0.51)In0.49P cells. Growth on misoriented substrates enabled the bandgap-voltage offset (W-oc = E-g/q - V-oc) of Ga0.51In0.49P cells to decrease from similar to 575 mV to similar to 565 mV, while that of (AlxGa1-x)(0.51)In0.49P cells remained nearly constant at 620 mV. The constant Woc as a function of substrate offcut for (AlxGa1-x)(0.51)In0.49P implies greater losses from non-radiative recombination compared with the Ga0.51In0.49P devices. In addition to larger Woc values, the (AlxGa1-x)(0.51)In0.49P cells exhibited significantly lower internal quantum efficiency (IQE) values than Ga0.51In0.49P cells due to recombination at the emitter/window layer interface. A thin emitter design is experimentally shown to be highly effective in improving IQE, particularly at short wavelengths. Our work shows that with further optimization of both cell structure and growth conditions, MBE-grown (AlxGa1-x)(0.51)In0.49P will be a promising wide-bandgap candidate material for high-efficiency, lattice-matched multi-junction solar cells. (C) 2015 AIP Publishing LLC.

  8. SU-E-T-80: Comparison of Fluence-Based RapidArc QAs Using EPID and MapCHECK 2

    SciTech Connect (OSTI)

    Jin, H; Jesseph, F; Ahmad, S

    2014-06-01

    Purpose: To compare the Varian aS-1000 EPID imager to the isocentrically mounted MapCHECK 2 diode array for RapidArc QAs as a function of photon beam energy. Methods: A Varian TrueBeam STx with an aS-1000 digital imaging panel was used to acquire RapidArc QA images for 13 patient plans; each plan QA was performed at 6, 8, 10 and 15MV energies. The Portal Dose Image Prediction algorithm in the Varian Eclipse treatment planning system (TPS) was used to create the comparison image for the EPID acquisition. A Sun Nuclear MapCHECK 2 diode array on an isocentric mounting fixture with 5 cm water-equivalent buildup was also used for the RapidArc QAs. A composite dose plane was taken from the Eclipse TPS for comparison to the MapCHECK 2 measurements. A gamma test was implemented in the Sun Nuclear Patient software with 10% threshold and absolute comparison for both QA methods. The two-tailed paired t-test was employed to analyze the statistical significance between two methods at the 95% confidence level. Results: The average gamma passing rates were greater than 95% at 3%/3mm using both methods for all four energies. The average passing rates were within 2.5% and 1.1% of each other when analyzed at 2%/2mm and 3%/3mm conditions, respectively. The EPID passing rates were somewhat better than the MapCHECK 2 when analyzed at 1%/1mm condition; this difference decreased with increasing energy (9.1% at 6MV to 2.7% at 15MV). The differences were not statistically significant for all criteria and energies (p-value ã 0.05). Conclusion: EPID-based RapidArc QA results are comparable to MapCHECK 2 when using 3%/3mm criteria at all four energies. EPID-based QA shows potential for being the superior device under strict gamma criteria.

  9. SU-E-T-223: Investigation of the Accuracy of Two-Dimensional Dose Distributions Measurement From High-Dose-Rate Brachytherapy Ir-192 Source Using Multiple-Diode-Array Detector (MapCheck2)

    SciTech Connect (OSTI)

    Taguenang, J; De La Fuente, T Herman; Ahmad, S; Ali, I

    2014-06-01

    Purpose: To investigate the dosimetric accuracy of multiple-diode-array detector (Mapcheck2) for high-dose-rate brachytherapy Ir-192 source. The two-dimensional (2D) dose distributions measured with MapCheck2 were validated with EBT2 Gafchromic film measurement and AAPM task-group- 43 (TG-43) modeling. Methods: 2D-dose distributions from Ir-192 source were measured with MapCheck2 and EBT2-films. MapCheck2 response was corrected for effects: directional dependence, diode and phantom heterogeneity. Optical density growth of the film was controlled by synchronized scanning of the film exposed to Ir-192 and calibration films exposed to 6 MV linac beams. Similarly, MapCheck2 response was calibrated to dose using 6 MV beams. An empirical model was developed for the dose distributions measured with Mapcheck2 that considered directional, diode and phantom heterogeneity corrections. The dose deposited in solid-state-detectors was modeled using a cavity theory model for the diode. This model was then validated with measurements using EBT2-films and calculations with TG-43. Results: The response of MapCheck2 has been corrected for different effects including: (a) directional dependence of 0–20% over angular range 0o–90o, (b) phantom heterogeneity (3%) and (c) diode heterogeneity (9%). The corrected dose distributions measured with MapCheck2 agreed well with the measured dose distributions from EBT2-film and with calculations using TG-43 within 5% over a wide range of dose levels and rates. The advantages of MapCheck2 include less noisy, linear and stable response compared with film. The response of MapCheck2 exposed to 192Ir-source showed no energy dependence similar to its response to MV energy beam. Detection spatial-resolution of individual diodes was 0.8×0.8 mm2, however, 2DMapCheck2 resolution is limited by distance between diodes (7.07 mm). Conclusion: The dose distribution measured with MapCheck2 agreed well within 5% with that measured using EBT2-films; and

  10. Commissioning of the Varian TrueBeam linear accelerator: A multi-institutional study

    SciTech Connect (OSTI)

    Glide-Hurst, C.; Bellon, M.; Wen, N.; Zhao, B.; Chetty, I. J.; Foster, R.; Speiser, M.; Solberg, T.; Altunbas, C.; Westerly, D.; Miften, M.; Altman, M.

    2013-03-15

    Purpose: Latest generation linear accelerators (linacs), i.e., TrueBeam (Varian Medical Systems, Palo Alto, CA) and its stereotactic counterpart, TrueBeam STx, have several unique features, including high-dose-rate flattening-filter-free (FFF) photon modes, reengineered electron modes with new scattering foil geometries, updated imaging hardware/software, and a novel control system. An evaluation of five TrueBeam linacs at three different institutions has been performed and this work reports on the commissioning experience. Methods: Acceptance and commissioning data were analyzed for five TrueBeam linacs equipped with 120 leaf (5 mm width) MLCs at three different institutions. Dosimetric data and mechanical parameters were compared. These included measurements of photon beam profiles (6X, 6XFFF, 10X, 10XFFF, 15X), photon and electron percent depth dose (PDD) curves (6, 9, 12 MeV), relative photon output factors (Scp), electron cone factors, mechanical isocenter accuracy, MLC transmission, and dosimetric leaf gap (DLG). End-to-end testing and IMRT commissioning were also conducted. Results: Gantry/collimator isocentricity measurements were similar (0.27-0.28 mm), with overall couch/gantry/collimator values of 0.46-0.68 mm across the three institutions. Dosimetric data showed good agreement between machines. The average MLC DLGs for 6, 10, and 15 MV photons were 1.33 {+-} 0.23, 1.57 {+-} 0.24, and 1.61 {+-} 0.26 mm, respectively. 6XFFF and 10XFFF modes had average DLGs of 1.16 {+-} 0.22 and 1.44 {+-} 0.30 mm, respectively. MLC transmission showed minimal variation across the three institutions, with the standard deviation <0.2% for all linacs. Photon and electron PDDs were comparable for all energies. 6, 10, and 15 MV photon beam quality, %dd(10){sub x} varied less than 0.3% for all linacs. Output factors (Scp) and electron cone factors agreed within 0.27%, on average; largest variations were observed for small field sizes (1.2% coefficient of variation, 10 MV, 2

  11. Field Emission Measurements from Niobium Electrodes

    SciTech Connect (OSTI)

    M. BastaniNejad, P.A. Adderley, J. Clark, S. Covert, J. Hansknecht, C. Hernandez-Garcia, R. Mammei, M. Poelker

    2011-03-01

    Increasing the operating voltage of a DC high voltage photogun serves to minimize space charge induced emittance growth and thereby preserve electron beam brightness, however, field emission from the photogun cathode electrode can pose significant problems: constant low level field emission degrades vacuum via electron stimulated desorption which in turn reduces photocathode yield through chemical poisoning and/or ion bombardment and high levels of field emission can damage the ceramic insulator. Niobium electrodes (single crystal, large grain and fine grain) were characterized using a DC high voltage field emission test stand at maximum voltage -225kV and electric field gradient > 10MV/m. Niobium electrodes appear to be superior to diamond-paste polished stainless steel electrodes.

  12. Modeling of cable terminations with embedded electrodes

    SciTech Connect (OSTI)

    Nikolajevic, S.V.; Pekaric-Nadj, N.M.; Dimitrijevic, R.M.; Djurovic, M.

    1996-12-31

    The paper describes a study of various cable termination constructions for medium voltage cross-linked polyethylene (MV XLPE) cables. A special device was used for electrical field measurements around the cable termination, which made it possible to monitor how stress relief materials with different relative permittivity, thickness of stress relief layer and placement of isolated or grounding embedded electrodes (EE) affect electrical stress grading. The results of measurement for each construction were examined by mathematical modeling based on finite element method (FEM). Also, the influence of dielectric losses in the termination was considered, when relative permittivity of the stress relief material is high. Finally, the selected constructions of cable termination were tested in service conditions with load cycling.

  13. Analysis of New High-Q0 SRF Cavity Tests by Nitrogen Gas Doping at Jefferson Lab

    SciTech Connect (OSTI)

    Palczewski, Ari D.; Geng, Rongli; Reece, Charles E.

    2014-12-01

    In order to refine systematic understanding and establish confident process control, Jefferson Lab has joined with partners to investigate and thoroughly characterize the dramatically higher Q0 of 1.3 GHz niobium cavities first reported by FNAL in 2013[1]. With partial support from the LCLS-II project, JLab has undertaken a parametric study of nitrogen doping in vacuum furnace at 800 C followed by variable depth surface removal in the 5 - 20 ?m range. Q0 above 31010 are typical at 2.0 K and 16 MV/m accelerating field. We report observations from the single cell study and current interpretations. In addition to the parametric single cell study, we also report on the ongoing serial testing of six nitrogen-doped 9-cell cavities as baseline prototypes for LCLS-II.

  14. A Pixel Readout Chip in 40 nm CMOS Process for High Count Rate Imaging Systems with Minimization of Charge Sharing Effects

    SciTech Connect (OSTI)

    Maj, Piotr; Grybos, P.; Szczgiel, R.; Kmon, P.; Drozd, A.; Deptuch, G.

    2013-11-07

    We present a prototype chip in 40 nm CMOS technology for readout of hybrid pixel detector. The prototype chip has a matrix of 18x24 pixels with a pixel pitch of 100 ?m. It can operate both in single photon counting (SPC) mode and in C8P1 mode. In SPC the measured ENC is 84 e? rms (for the peaking time of 48 ns), while the effective offset spread is below 2 mV rms. In the C8P1 mode the chip reconstructs full charge deposited in the detector, even in the case of charge sharing, and it identifies a pixel with the largest charge deposition. The chip architecture and preliminary measurements are reported.

  15. Thin Metal Oxide Films to Modify a Window Layer in CdTe-Based Solar Cells for Improved Performance

    SciTech Connect (OSTI)

    Lemmon, John P.; Polikarpov, Evgueni; Bennett, Wendy D.; Kovarik, Libor

    2012-05-25

    We report on CdS/CdTe photovoltaic devices that contain a thin Ta₂O₅ film deposited onto the CdS window layer by sputtering. We show that for thicknesses below 5 nm, Ta₂O₅ films between CdS and CdTe positively affect the solar cell performance, improving JSC, VOC, and the cell power conversion efficiency despite the insulating nature of the interlayer material. Using the Ta₂O₅ interlayer, a VOC gain of over 100 mV was demonstrated compared to a CdTe/CdS baseline. Application of a 1nm Ta₂O₅ interlayer enabled the fabrication of CdTe solar cells with extremely thin (less than 30 nm) CdS window layers. The efficiency of these cells exceeded that of a base line cell with 95 nm of CdS.

  16. Vertical stability requirements for ARIES-I reactor

    SciTech Connect (OSTI)

    Bathke, C.G.; Jardin, S.C.; Leuer, J.A.; Ward, D.J.; Princeton Univ., NJ . Plasma Physics Lab.; General Atomics, San Diego, CA; Princeton Univ., NJ . Plasma Physics Lab.)

    1989-01-01

    The vertical stability of the ARIES-I reactor design is analyzed with the NOVA-W, PSTAB, and TSC codes. A growth rate of {approximately}5.7 s{sup -1} is predicted for a vacuum vessel positioned behind the scrapeoff, first wall, and blanket (0.7 in inboard and 0.9 in outboard thickness) and acting as a passive stabilizer. A reactive power of {approximately}2 MV A would be required for active feedback coils located outside of the TF coils {approximately}3 m to correct a 50-mm vertical displacement of the magnetic axis. A multipolar expansion technique used in the TSC analysis is also used to examine options that minimize stored energy. 10 refs., 8 figs., 2 tabs.

  17. CORROSION STUDY FOR THE EFFLUENT TREATMENT FACILITY (ETF) CHROME (VI) REDUCTANT SOLUTION USING 304 & 316L STAINLESS STEEL

    SciTech Connect (OSTI)

    DUNCAN, J.B.

    2007-06-27

    The Effluent Treatment Facility has developed a method to regenerate spent resin from the groundwater pump and treat intercepting chrome(VI) plumes (RPP-RPT-32207, Laboratory Study on Regeneration of Spent DOWEX 21K 16-20 Mesh Ion Exchange Resin). Subsequent laboratory studies have shown that the chrome(VI) may be reduced to chrome(III) by titrating with sodium metabisulfite to an oxidation reduction potential (ORP) of +280 mV at a pH of 2. This test plan describes the use of cyclic potentiodynamic polarization and linear polarization techniques to ascertain the electrochemical corrosion and pitting propensity of the 304 and 316L stainless steel in the acidified reducing the solution that will be contained in either the secondary waste receiver tank or concentrate tank.

  18. INFLUENCE OF TEMPERATURE ON THE CORROSION POTENTIAL OF THE 241-AN-102 MULTI PROBE CORROSION MONITORING SYSTEM SECONDARY REFERENCE ELECTRODES

    SciTech Connect (OSTI)

    EDGEMON GL; TAYLOR TM

    2008-09-30

    A test program using 241-AN-102 waste simulants and metallic secondary reference electrodes similar to those used on the 241-AN-102 MPCMS was performed to characterize the relationship between temperature and secondary reference electrode open-circuit corrosion potential. This program showed that the secondary reference electrodes can be used to make tank and tank steel corrosion potential measurements, but that a correction factor of approximately 2 mV per degree Celsius of temperature difference must be applied, where temperature difference is defined as the difference between tank temperature at the time of measurement and 30 C, the average tank temperature during the first several months of 241-AN-102 MPCMS operation (when the corrosion potentials of the secondary reference electrodes were being recorded relative to the primary reference electrodes).

  19. Hysteresis-free high-temperature precise bimorph actuators produced by direct bonding of lithium niobate wafers

    SciTech Connect (OSTI)

    Shur, V. Ya.; Baturin, I. S.; Mingaliev, E. A.; Zorikhin, D. V.; Udalov, A. R.; Greshnyakov, E. D.

    2015-02-02

    The current paper presents a piezoelectric bimorph actuator produced by direct bonding of lithium niobate wafers with the mirrored Y and Z axes. Direct bonding technology allowed to fabricate bidomain plate with precise positioning of ideally flat domain boundary. By optimizing the cutting angle (128° Y-cut), the piezoelectric constant became as large as 27.3 pC/N. Investigation of voltage dependence of bending displacement confirmed that bimorph actuator has excellent linearity and hysteresis-free. Decrease of the applied voltage down to mV range showed the perfect linearity up to the sub-nm deflection amplitude. The frequency and temperature dependences of electromechanical transmission coefficient in wide temperature range (from 300 to 900 K) were investigated.

  20. Well Completion Report for Corrective Action Unit 447, Project Shoal Area, Churchill County, Nevada, Rev. No.: 0

    SciTech Connect (OSTI)

    Rick Findlay

    2006-09-01

    This Well Completion Report is being provided as part of the implementation of the Corrective Action Decision Document (CADD)/Corrective Action Plan (CAP) for Corrective Action Unit (CAU) 447 (NNSA/NSO, 2006a). The CADD/CAP is part of an ongoing U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office (NNSA/NSO) funded project for the investigation of CAU 447 at the Project Shoal Area (PSA). All work performed on this project was conducted in accordance with the ''Federal Facility Agreement and Consent Order'' (FFACO) (1996), and all applicable Nevada Division of Environmental Protection (NDEP) policies and regulations. Investigation activities included the drilling, construction, and development of three monitoring/validation (MV) wells at the PSA. This report summarizes the field activities and data collected during the investigation.

  1. UPGRADE AND OPERATION OF THE BNL TANDEMS FOR RHIC INJECTION.

    SciTech Connect (OSTI)

    STESKI,D.B.; ALESSI,J.; BENJAMIN,J.; CARLSON,C.; MANNI,M.; THIEBERGER,P.; WIPLICH,M.

    2001-06-18

    One of the tandem Van de Graaffs (MP7) at Brookhaven National Laboratory (BNL) has successfully completed its first year as an injector for the Relativistic Heavy Ion Collider (RHIC). The tandem provided pulsed beam of Au{sup +32} (peak intensity 80 e{mu}A, 500{micro}s) with only 17 hours of downtime during a 5 month run. Improvements are being made to further increase the intensity of the gold beam for the experimental run starting in 2001. A second tandem Van de Graaff (MP6) has been extensively upgraded and can now reach a terminal voltage of over 14MV. A beamline has been constructed to transport the MP6 beam around MP7 and then connect to the existing MP7 beamlines. This has allowed MP6 to deliver beam to local target rooms for an outside user program, while MP7 has simultaneously injected RHIC. MP6 can also be used as an injector for RHIC.

  2. Low-Potential Stable NADH Detection at Carbon-Nanotube-Modified Glassy Carbon Electrodes

    SciTech Connect (OSTI)

    Musameh, Mustafa; Wang, Joseph; Merkoci, Arben; Lin, Yuehe )

    2002-11-22

    Carbon-nanotube (CNT) modified glassy-carbon electrodes exhibiting strong and stable electrocatalytic response toward NADH are described. A substantial (490 mV) decrease in the overvoltage of the NADH oxidation reaction (compared to ordinary carbon electrodes) is observed using single-wall and multi-wall carbon-nanotube coatings, with oxidation starting at ca.?0.05V (vs. Ag/AgCl; pH 7.4). Furthermore, the NADH amperometric response of the coated electrodes is extremely stable, with 96 and 90% of the initial activity remaining after 60min stirring of 2x10-4M and 5x10-3M NADH solutions, respectively (compared to 20 and 14% at the bare surface). The CNT-coated electrodes thus allow highly-sensitive, low-potential, stable amperometric sensing. Such ability of carbon-nanotubes to promote the NADH electron-transfer reaction suggests great promise for dehydrogenase-based amperometric biosensors.

  3. Implementation of Tunneling Passivated Contacts into Industrially Relevant n-Cz Si Solar Cells

    SciTech Connect (OSTI)

    Nemeth, William; LaSalvia, Vincenzo; Page, Matthew R.; Warren, Emily L.; Dameron, Arrelaine; Norman, Andrew G.; Lee, Benjamin G.; Young, David L.; Stradins, Paul

    2015-06-14

    We identify bottlenecks, and propose solutions, to implement a B-diffused front emitter and a backside pc-Si/SiO2 pasivated tunneling contact into high efficiency n-Cz Si cells in an industrially relevant way. We apply an O-precipitate dissolution treatment to make n-Cz wafers immune to bulk lifetime process degradation, enabling robust, passivated B front emitters with J0 <; 20fA/cm2. Adding ultralow recombination n+ pc-Si/SiO2 back contacts enables pre-metallized cells with iVoc=720 mV and J0=8.6 fA/cm2. However, metallization significantly degrades performance of these contacts due to pinholes and possibly, grain boundary diffusion of primary metal and source contaminates such as Cu. An intermediate, doped a-Si:H capping layer is found to significantly block the harmful metal penetration into pc-Si.

  4. Resetting the Defect Chemistry in CdTe

    SciTech Connect (OSTI)

    Metzger, Wyatt K.; Burst, James; Albin, David; Colegrove, Eric; Moseley, John; Duenow, Joel; Farrell, Stuart; Moutinho, Helio; Reese, Matt; Johnston, Steve; Barnes, Teresa; Perkins, Craig; Guthrey, Harvey; Al-Jassim, Mowafak

    2015-06-14

    CdTe cell efficiencies have increased from 17% to 21% in the past three years and now rival polycrystalline Si [1]. Research is now targeting 25% to displace Si, attain costs less than 40 cents/W, and reach grid parity. Recent efficiency gains have come largely from greater photocurrent. There is still headroom to lower costs and improve performance by increasing open-circuit voltage (Voc) and fill factor. Record-efficiency CdTe cells have been limited to Voc <; 880 mV, whereas GaAs can attain Voc of 1.10 V with a slightly smaller bandgap [2,3]. To overcome this barrier, we seek to understand and increase lifetime and carrier concentration in CdTe. In polycrystalline structures, lifetime can be limited by interface and grain-boundary recombination, and attaining high carrier concentration is complicated by morphology.

  5. Symmetry-dependent electron-electron interaction in coherent tunnel junctions resolved by measurements of zero-bias anomaly

    SciTech Connect (OSTI)

    Liu, Liang; Niu, Jiasen; Xiang, Li; Wei, Jian; Li, D. -L.; Feng, J. -F.; Han, X. -F.; Zhang, X. -G.; Coey, J. M. D.

    2014-11-18

    We provide experimental evidence that zero bias anomaly in the differential resistance of magnetic tunnel junctions (MTJs) is due to electron-electron interaction (EEI). Magnon effect is excluded by measuring at low temperatures down to 0.2 K and with reduced AC measurement voltages down to 0.06 mV. The normalized change of conductance is proportional to ln (eV /kB T ), consistent with the Altshuler-Aronov theory of tunneling with EEI but inconsistent with magnetic impurity scattering. The slope of the ln (eV /kBT ) dependence is symmetry dependent, i.e., MTJs with symmetry filtering show di erent slopes for P and AP states, while those without symmetry filtering (amorphous barriers) have nearly the same slopes for P and AP.

  6. High power test results of the first SRRC/ANL high current L-band RF gun.

    SciTech Connect (OSTI)

    Ho, C. H.

    1998-09-11

    A joint program is underway between the SRRC (Synchrotrons Radiation Research Center, Taiwan) and ANL (Argonne National Laboratory, USA) for developing a high current L-band photocathode rf guns. We have constructed an L-Band (1.3 Ghz), single cell rf photocathode gun and conducted low power tests at SRRC. High power rf conditioning of the cavity has been completed at ANL. In this paper we report on the construction and high power test results. So far we have been able to achieve > 120 MV/m axial electric field with minimal dark current. This gun will be used to replace the AWA (Argonne Wakefield Accelerator)[l] high current gun.

  7. Formation of BaSi{sub 2} heterojunction solar cells using transparent MoO{sub x} hole transport layers

    SciTech Connect (OSTI)

    Du, W.; Takabe, R.; Baba, M.; Takeuchi, H.; Toko, K.; Hara, K. O.; Usami, N.; Suemasu, T.

    2015-03-23

    Heterojunction solar cells that consist of 15?nm thick molybdenum trioxide (MoO{sub x}, x?mV and a short circuit current density of 0.5?mA/cm{sup 2} were obtained under AM1.5 illumination. The photocurrent density under a reverse bias voltage of ?1 V reached 25?mA/cm{sup 2}, which demonstrates the significant potential of BaSi{sub 2} for solar cell applications.

  8. Method of inhibiting voltage suppression lithium/fluorinated carbon batteries

    SciTech Connect (OSTI)

    Shia, G.A.; Friedland, D.J.

    1987-08-11

    An improved lithium/fluorinated carbon battery is described wherein the cathode comprises a blend of at least two different CF/sub x/ compositions which are derived from petroleum-based coke products which have been prepared by heat treatment at a temperature between about 800/sup 0/C and 2,0006/sup 0/C: (a) a bulk CF/sub x/ and (b) an additive CF/sub x/ and wherein from about 0.5 percent to about 50 percent of (b) is characterized as having a closed circuit voltage of at least 150 mV above the plateau voltage of the bulk CF/sub x/ and a specific capacity above 600 mAH/g. A method is also described for the elimination of suppression of the closed circuit voltage of a Li/CF/sub x/ battery during the initial part of its discharge.

  9. Towards quantitative off-axis electron holographic mapping of the electric field around the tip of a sharp biased metallic needle

    SciTech Connect (OSTI)

    Beleggia, M.; Kasama, T.; Larson, D. J.; Kelly, T. F.; Dunin-Borkowski, R. E.; Pozzi, G.

    2014-07-14

    We apply off-axis electron holography and Lorentz microscopy in the transmission electron microscope to map the electric field generated by a sharp biased metallic tip. A combination of experimental data and modelling provides quantitative information about the potential and the field around the tip. Close to the tip apex, we measure a maximum field intensity of 82 MV/m, corresponding to a field k factor of 2.5, in excellent agreement with theory. In order to verify the validity of the measurements, we use the inferred charge density distribution in the tip region to generate simulated phase maps and Fresnel (out-of-focus) images for comparison with experimental measurements. While the overall agreement is excellent, the simulations also highlight the presence of an unexpected astigmatic contribution to the intensity in a highly defocused Fresnel image, which is thought to result from the geometry of the applied field.

  10. Si/SiGe electron resonant tunneling diodes with graded spacer wells

    SciTech Connect (OSTI)

    Paul, D. J.; See, P.; Bates, R.; Griffin, N.; Coonan, B. P.; Redmond, G.; Crean, G. M.; Zozoulenko, I. V.; Berggren, K.-F.; Hollander, B.

    2001-06-25

    Resonant tunneling diodes have been fabricated using graded Si{sub 1{minus}x}Ge{sub x} (x=0.3{r_arrow}0.0) spacer wells and strained Si{sub 0.4}Ge{sub 0.6} barriers on a relaxed Si{sub 0.7}Ge{sub 0.3} n-type substrate which demonstrates negative differential resistance at up to 100 K. This design is aimed at reducing the voltage at which the peak current density is achieved. Peak current densities of 0.08A/cm{sup 2} with peak-to-valley current ratios of 1.67 have been achieved for a low peak voltage of 40 mV at 77 K. This represents an improvement of over an order of magnitude compared to previous work. {copyright} 2001 American Institute of Physics.

  11. Demonstration of forward inter-band tunneling in GaN by polarization engineering

    SciTech Connect (OSTI)

    Krishnamoorthy, Sriram; Park, Pil Sung; Rajan, Siddharth

    2011-12-05

    We report on the design, fabrication, and characterization of GaN interband tunnel junction showing forward tunneling characteristics. We have achieved very high forward tunneling currents (153 mA/cm{sup 2} at 10 mV, and 17.7 A/cm{sup 2} peak current) in polarization-engineered GaN/InGaN/GaN heterojunction diodes grown by plasma assisted molecular beam epitaxy. We also report the observation of repeatable negative differential resistance in interband III-Nitride tunnel junctions, with peak-valley current ratio of 4 at room temperature. The forward current density achieved in this work meets the typical current drive requirements of a multi-junction solar cell.

  12. Role of polycrystallinity in CdTe and CuInSe sub 2 photovoltaic cells

    SciTech Connect (OSTI)

    Sites, J.R. )

    1991-01-01

    The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.

  13. High-performance Si microwire photovoltaics

    SciTech Connect (OSTI)

    Kelzenberg, Michael D.; Turner-Evans, Daniel B.; Putnam, Morgan C.; Boettcher, Shannon W.; Briggs, Ryan M.; Baek, Jae Y.; Lewis, Nathan S.; Atwater, Harry A.

    2011-01-07

    Crystalline Si wires, grown by the vaporliquidsolid (VLS) process, have emerged as promising candidate materials for low-cost, thin-film photovoltaics. Here, we demonstrate VLS-grown Si microwires that have suitable electrical properties for high-performance photovoltaic applications, including long minority-carrier diffusion lengths (Ln>> 30 m) and low surface recombination velocities (S << 70 cms-1). Single-wire radial pn junction solar cells were fabricated with amorphous silicon and silicon nitride surface coatings, achieving up to 9.0% apparent photovoltaic efficiency, and exhibiting up to ~600 mV open-circuit voltage with over 80% fill factor. Projective single-wire measurements and optoelectronic simulations suggest that large-area Si wire-array solar cells have the potential to exceed 17% energy-conversion efficiency, offering a promising route toward cost-effective crystalline Si photovoltaics.

  14. Electrochemically induced deposition method to prepare {gamma}-MnO{sub 2}/multi-walled carbon nanotube composites as electrode material in supercapacitors

    SciTech Connect (OSTI)

    Fan Zhen

    2008-08-04

    The {gamma}-MnO{sub 2}/multi-walled carbon nanotube ({gamma}-MnO{sub 2}/MWNT) composite has been prepared by electrochemically induced deposition method. The morphology and crystal structure of the composite were investigated by X-ray diffraction and scanning electron microscopy, respectively. The capacitive properties of the {gamma}-MnO{sub 2}/MWNT composite have been investigated by cyclic voltammetry (CV). A specific capacitance (based on {gamma}-MnO{sub 2}) as high as 579 F g{sup -1} is obtained at a scan rate of 10 mV s{sup -1} in 0.1 M Na{sub 2}SO{sub 4} aqueous solution. Additionally, the {gamma}-MnO{sub 2}/MWNT composite electrode shows excellent long-term cycle stability (only 2.4% decrease of the specific capacitance is observed after 500 CV cycles)

  15. TiN/VN composites with core/shell structure for supercapacitors

    SciTech Connect (OSTI)

    Dong, Shanmu; Chen, Xiao; Gu, Lin; Zhou, Xinhong; Wang, Haibo; Liu, Zhihong; Han, Pengxian; Yao, Jianhua; Wang, Li; Cui, Guanglei; Chen, Liquan; Institute of Physics, Chinese Academy of Sciences, Beijing 100080

    2011-06-15

    Research highlights: {yields} Vanadium and titanium nitride nanocomposite with core-shell structure was prepared. {yields} TiN/VN composites with different V:Ti molar ratios were obtained. {yields} TiN/VN composites can provide promising electronic conductivity and favorable capacity storage. -- Abstract: TiN/VN core-shell composites are prepared by a two-step strategy involving coating of commercial TiN nanoparticles with V{sub 2}O{sub 5}.nH{sub 2}O sols followed by ammonia reduction. The highest specific capacitance of 170 F g{sup -1} is obtained when scanned at 2 mV s{sup -1} and a promising rate capacity performance is maintained at higher voltage sweep rates. These results indicate that these composites with good electronic conductivity can deliver a favorable capacity performance.

  16. Laser-seeded modulation instability in a proton driver plasma wakefield accelerator

    SciTech Connect (OSTI)

    Siemon, Carl; Khudik, Vladimir; Austin Yi, S.; Shvets, Gennady; Pukhov, Alexander

    2013-10-15

    A new method for initiating the modulation instability (MI) of a proton beam in a proton driver plasma wakefield accelerator using a short laser pulse preceding the beam is presented. A diffracting laser pulse is used to produce a plasma wave that provides a seeding modulation of the proton bunch with the period equal to that of the plasma wave. Using the envelope description of the proton beam, this method of seeding the MI is analytically compared with the earlier suggested seeding technique that involves an abrupt truncation of the proton bunch. The full kinetic simulation of a realistic proton bunch is used to validate the analytic results. It is further used to demonstrate that a plasma density ramp placed in the early stages of the laser-seeded MI leads to its stabilization, resulting in sustained accelerating electric fields (of order several hundred MV/m) over long propagation distances (∼100–1000 m)

  17. MAGIC: Marine ARM GPCI Investigation of Clouds

    SciTech Connect (OSTI)

    Lewis, ER; Wiscombe, WJ; Albrecht, BA; Bland, GL; Flagg, CN; Klein, SA; Kollias, P; Mace, G; Reynolds, RM; Schwartz, SE; Siebesma, AP; Teixeira, J; Wood, R; Zhang, M

    2012-10-03

    The second Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF2) will be deployed aboard the Horizon Lines cargo container ship merchant vessel (M/V) Spirit for MAGIC, the Marine ARM GPCI1 Investigation of Clouds. The Spirit will traverse the route between Los Angeles, California, and Honolulu, Hawaii, from October 2012 through September 2013 (except for a few months in the middle of this time period when the ship will be in dry dock). During this field campaign, AMF2 will observe and characterize the properties of clouds and precipitation, aerosols, and atmospheric radiation; standard meteorological and oceanographic variables; and atmospheric structure. There will also be two intensive observational periods (IOPs), one in January 2013 and one in July 2013, during which more detailed measurements of the atmospheric structure will be made.

  18. Modifications of Superconducting Properties of Niobium Caused by Nitrogen Doping Recipes for High Q Cavities

    SciTech Connect (OSTI)

    Vostrikov, Alexander; Checchin, Mattia; Grassellino, Anna; Kim, Young-Kee; Romanenko, Alexander

    2015-06-01

    A study is presented on the superconducting properties of niobium used for the fabrication of the SRF cavities after treating by recently discovered nitrogen doping methods. Cylindrical niobium samples have been subjected to the standard surface treatments applied to the cavities (electro-polishing, l 20°C bake) and compared with samples treated by additional nitrogen doping recipes routinely used to reach ultra-high quality factor values (>3· 1010 at 2 K, 16 MV/m). The DC magnetization curves and the complex magnetic AC susceptibility have been measured. Evidence for the lowered field of first flux penetration after nitrogen doping is found suggesting a correlation with the lowered quench fields. Superconducting critical temperatures Tc = 9.25 K are found to be in agreement with previous measurements, and no strong effect on the critical surface field (Bd) from nitrogen doping was found.

  19. Reproducibility of High-Q SRF Cavities by High Temperature Heat Treatment

    SciTech Connect (OSTI)

    Dhakal, Pashupati; Ciovati, Gianluigi; Kneisel, Peter; Myneni, Ganapati Rao

    2014-07-01

    Recent work on high-temperature (> 600 °C) heat treatment of ingot Nb cavities in a customized vacuum furnace for several hours showed the possibility of achieving Q0-values of up to ~5×1010 at 2.0 K, 1.5 GHz and accelerating gradients of ~20 MV/m. This contribution presents results on further studies of the heat treatment process to produce cavities with high Q0 values for continuous-wave accelerator application. Single-cell cavities of different Nb purity have been processed through few cycles of heat-treatments and chemical etching. Measurements of Q0 as a function of temperature at low RF field and of Q0 as a function of the RF field at or below 2.0 K have been made after each treatment. Measurements by TOF-SIMS of the impurities depth profiles were made on samples heat treated with the cavities.

  20. Independent review of estimated load reductions for PJM's small customer load response pilot project

    SciTech Connect (OSTI)

    Heffner, G.; Moezzi, M.; Goldman, C.

    2004-06-01

    This study describes the results of a low-cost approach used to measure reported load reductions from a residential electric water heater (EWH) load control program operated as part of PJM Interconnection's Demand Response small customer pilot program. Lawrence Berkeley National Laboratory (LBNL) conducted this independent review of the engineering estimates for EWH load control reported by a Curtailment Service Provider (CSP) at PJM's request. LBNL employed low-cost measurement and verification (M&V) approaches that utilized existing interval metering equipment to monitor results for a series of load control tests. The CSP collected hourly load data for two substations and several hundred households over a six-week period in October and November 2003. During this time period, the CSP operated its electric water heater load control program during pre-specified test periods in the morning, afternoon and early evening. LBNL then analyzed substation and premise-level data from these tests in order to verify the diversified demand reductions claimed by the CSP for customers participating in the EWH load control program. We found that the observed load reductions for the premise-level data aggregated over all households in the two participating electric cooperatives were, respectively, 40 percent-60 percent less and 3 percent less-10 percent higher than the estimated diversified demand reduction values assumed by the CSP, depending on whether observed or normalized results are considered. We also analyzed sub-station level data and found that the observed load reductions during the test periods were significantly lower than expected, although confounding influences and operational problems signifiogram during pre-specified test periods in the morning, afternoon and early evening. LBNL then analyzed substation and premise-level data from these tests in order to verify the diversified demand reductions claimed by the CSP for customers participating in the EWH load control

  1. Cold RF test and associated mechanical features correlation of a TESLA-style 9-cell superconducting niobium cavity built in China

    SciTech Connect (OSTI)

    Dai, Jing; Quan, Sheng-Wen; Zhang, Bao-Cheng; Lin, Lin; Hao, Jian-Kui; Zhu, Feng; Xu, Wen-Can; He, Fei-Si; Jin, Song; Wang, Fang; Liu, Ke-Xin; Geng, R L; Zhao, Kui

    2012-02-01

    The RF performance of a 1.3 GHz 9-cell superconducting niobium cavity was evaluated at cryogenic temperatures following surface processing by using the standard ILC-style recipe. The cavity is a TESLA-style 9-cell superconducting niobium cavity, with complete end group components including a higher order mode coupler, built in China for practical applications. An accelerating gradient of 28.6 MV/m was achieved at an unloaded quality factor of 4 x 10{sup 9}. The morphological property of mechanical features on the RF surface of this cavity was characterized through optical inspection. Correlation between the observed mechanical features and the RF performance of the cavity is attempted.

  2. Review of R&D at DESY on ingot niobium for accelerators

    SciTech Connect (OSTI)

    Navitski, Aliaksandr Sekutowicz, Jacek Singer, Waldemar Singer, Xenia

    2015-12-04

    An R&D program at DESY exploring the potential of the production of 1.3 GHz TESLA shape cavities from large grain or ingot niobium material has been carried out as a feasibility study for using ingot niobium material for the European X-ray Free-Electron Laser project. The most important issues like feasibility of the fabrication of niobium discs from ingots, material properties, cavity fabrication, treatment, and finally the cryogenic radiofrequency (RF) performance of the cavity in the accelerator modules are presented and discussed. At least 25% higher intrinsic quality factor comparing to conventional fine-grain niobium and high accelerating gradient of up to 45 MV/m have been demonstrated during the cryogenic RF tests both in the vertical cryostats and in a completely assembled accelerating cryo-module.

  3. Measurement of the tradeoff between intrinsic emittance and quantum efficiency from a NaKSb photocathode near threshold

    SciTech Connect (OSTI)

    Maxson, Jared Cultrera, Luca; Gulliford, Colwyn; Bazarov, Ivan

    2015-06-08

    We measure the tradeoff between the quantum efficiency and intrinsic emittance from a NaKSb photocathode at three increasing wavelengths (635, 650, and 690 nm) at or below the energy of the bandgap plus the electron affinity, hν≤E{sub g}+E{sub a}. These measurements were performed using a high voltage dc gun for varied photocathode surface fields of 1.4−4.4 MV/m. Measurements of intrinsic emittance are performed using two different methods and were found to agree. At the longest wavelength available, 690 nm, the intrinsic emittance was 0.26 μm/mm-rms with a quantum efficiency of ∼10{sup −4}. The suitability of NaKSb emitting at threshold for various low emittance applications is discussed.

  4. Initial Testing of the Mark-0 X-Band RF Gun at SLAC

    SciTech Connect (OSTI)

    Vlieks, Arnold; Adolphsen, C.; Dolgashev, V.; Lewandowski, J.; Limborg, Cecile; Weathersby, S.; /SLAC

    2012-06-06

    A new X-band RF gun (Mark-0) has been assembled, tuned and was tested in the ASTA facility at SLAC. This gun has been improved from an earlier gun used in Compton-scattering experiments at SLAC by the introduction of a racetrack dual-input coupler to reduce quadrupole fields. Waveguide-to-coupler irises were also redesigned to reduce surface magnetic fields and therefore peak pulse surface heating. Tests of this photocathode gun will allow us to gain early operational experience for beam tests of a new gun with further improvements (Mark-1) being prepared for SLAC's X-Band Test Area (XTA) program and the LLNL MEGa-ray program. Results of current testing up to {approx} 200 MV/m peak surface Electric fields are presented.

  5. Electron gun jitter effects on beam bunching

    SciTech Connect (OSTI)

    Liu, M. S.; Iqbal, M.

    2014-02-15

    For routine operation of Beijing Electron Positron Collider II (BEPCII) linac, many factors may affect the beam bunching process directly or indirectly. We present the measurements and analyses of the gun timing jitter, gun high voltage jitter, and beam energy at the exit of the standard acceleration section of the linac quantitatively. Almost 80 mV and more than 200 ps of gun high voltage and time jitters have ever been measured, respectively. It was analyzed that the gun timing jitter produced severe effects on beam energy than the gun high voltage jitter, if the timing jitter exceeded 100 ps which eventually deteriorates both the beam performance and the injection rate to the storage ring.

  6. An X-Band Gun Test Area at SLAC

    SciTech Connect (OSTI)

    Limborg-Deprey, C.; Adolphsen, C.; Chu, T.S.; Dunning, M.P.; Jobe, R.K.; Jongewaard, E.N.; Hast, C.; Vlieks, A.E.; Wang, F.; Walz, D.R.; Marsh, R.A.; Anderson, S.G.; Hartemann, F.V.; Houck, T.L.; /LLNL, Livermore

    2012-09-07

    The X-Band Test Area (XTA) is being assembled in the NLCTA tunnel at SLAC to serve as a test facility for new RF guns. The first gun to be tested will be an upgraded version of the 5.6 cell, 200 MV/m peak field X-band gun designed at SLAC in 2003 for the Compton Scattering experiment run in ASTA. This new version includes some features implemented in 2006 on the LCLS gun such as racetrack couplers, increased mode separation and elliptical irises. These upgrades were developed in collaboration with LLNL since the same gun will be used in an injector for a LLNL Gamma-ray Source. Our beamline includes an X-band acceleration section which takes the electron beam up to 100 MeV and an electron beam measurement station. Other X-Band guns such as the UCLA Hybrid gun will be characterized at our facility.

  7. Ultraviolet photosensitivity of sulfur-doped micro- and nano-crystalline diamond

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mendoza, Frank; Makarov, Vladimir; Hidalgo, Arturo; Weiner, Brad; Morell, Gerardo

    2011-06-06

    The room-temperature photosensitivity of sulfur-doped micro- (MCD), submicro- (SMCD) and nano- (NCD) crystalline diamond films synthesized by hot-filament chemical vapor deposition was studied. The structure and composition of these diamond materials were characterized by Raman spectroscopy, scanning electron microscopy and X-ray diffraction. The UV sensitivity and response time were studied for the three types of diamond materials using a steady state broad UV excitation source and two pulsed UV laser radiations. It was found that they have high sensitivity in the UV region, as high as 109 sec-1mV-1 range, linear response in a broad spectral range below 320 nm, photocurrentsmore » around ~10-5 A, and short response time better than 100 ns, which is independent of fluency intensity. A phenomenological model was applied to help understand the role of defects and dopant concentration on the materials’ photosensitivity.« less

  8. The Dielectric Wall Accelerator

    SciTech Connect (OSTI)

    Caporaso, George J.; Chen, Yu-Jiuan; Sampayan, Stephen E.

    2009-01-01

    The Dielectric Wall Accelerator (DWA), a class of induction accelerators, employs a novel insulating beam tube to impress a longitudinal electric field on a bunch of charged particles. The surface flashover characteristics of this tube may permit the attainment of accelerating gradients on the order of 100 MV/m for accelerating pulses on the order of a nanosecond in duration. A virtual traveling wave of excitation along the tube is produced at any desired speed by controlling the timing of pulse generating modules that supply a tangential electric field to the tube wall. Because of the ability to control the speed of this virtual wave, the accelerator is capable of handling any charge to mass ratio particle; hence it can be used for electrons, protons and any ion. The accelerator architectures, key technologies and development challenges will be described.

  9. Results from Coupled Optical and Electrical Sentaurus TCAD Models of a Gallium Phosphide on Silicon Electron Carrier Selective Contact Solar Cell

    SciTech Connect (OSTI)

    Limpert, Steven; Ghosh, Kunal; Wagner, Hannes; Bowden, Stuart; Honsberg, Christiana; Goodnick, Stephen; Bremner, Stephen; Green, Martin

    2014-06-09

    We report results from coupled optical and electrical Sentaurus TCAD models of a gallium phosphide (GaP) on silicon electron carrier selective contact (CSC) solar cell. Detailed analyses of current and voltage performance are presented for devices having substrate thicknesses of 10 μm, 50 μm, 100 μm and 150 μm, and with GaP/Si interfacial quality ranging from very poor to excellent. Ultimate potential performance was investigated using optical absorption profiles consistent with light trapping schemes of random pyramids with attached and detached rear reflector, and planar with an attached rear reflector. Results indicate Auger-limited open-circuit voltages up to 787 mV and efficiencies up to 26.7% may be possible for front-contacted devices.

  10. Portable radiography system using a relativistic electron beam

    DOE Patents [OSTI]

    Hoeberling, R.F.

    1987-09-22

    A portable radiographic generator is provided with an explosive magnetic flux compression generator producing the high voltage necessary to generate a relativistic electron beam. The relativistic electron beam is provided with target materials which generates the desired radiographic pulse. The magnetic flux compression generator may require at least two conventional explosively driven generators in series to obtain a desired output voltage of at least 1 MV. The cathode and anode configuration of the diode are selected to provide a switching action wherein a high impedance load is presented to the magnetic flux compression generator when the high voltage is being generated, and thereafter switching to a low impedance load to generate the relativistic electron beam. Magnetic flux compression generators can be explosively driven and provided in a relatively compact, portable form for use with the relativistic x-ray equipment. 8 figs.

  11. Band edge engineering of oxide photoanodes for photoelectrochemical water splitting: Integration of subsurface dipoles with atomic-scale control

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hikita, Yasuyuki; Nishio, Kazunori; Seitz, Linsey C.; Chakthranont, Pongkarn; Tachikawa, Takashi; Jaramillo, Thomas F.; Hwang, Harold Y.

    2016-01-22

    One of the crucial parameters dictating the efficiency of photoelectrochemical water-splitting is the semiconductor band edge alignment with respect to hydrogen and oxygen redox potentials. Despite the importance of metal oxides in their use as photoelectrodes, studies to control the band edge alignment in aqueous solution have been limited predominantly to compound semiconductors with modulation ranges limited to a few hundred mV. The ability to modulate the flat band potential of oxide photoanodes by as much as 1.3 V, using the insertion of subsurface electrostatic dipoles near a Nb-doped SrTiO3/aqueous electrolyte interface is reported. Lastly, the tunable range achieved farmore » exceeds previous reports in any semiconductor/aqueous electrolyte system and suggests a general design strategy for highly efficient oxide photoelectrodes.« less

  12. High-performance InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Tsai, J.-H. Chiu, S.-Y.; Lour, W.-S.; Guo, D.-F.

    2009-07-15

    In this article, a novel InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor is first demonstrated. Though the valence band discontinuity at InGaP/GaAs heterojunction is relatively large, the addition of a {delta}-doped sheet between two spacer layers at the emitter-base (E-B) junction effectively eliminates the potential spike and increases the confined barrier for electrons, simultaneously. Experimentally, a high current gain of 25 and a relatively low E-B offset voltage of 60 mV are achieved. The offset voltage is much smaller than the conventional InGaP/GaAs pnp HBT. The proposed device could be used for linear amplifiers and low-power complementary integrated circuit applications.

  13. BNL 703 MHz SRF cryomodule demonstration

    SciTech Connect (OSTI)

    Burrill,A.; Ben-Zvi, I.; Calaga, R.; Dalesio, L.; Dottavio, T.; Gassner, D.; Hahn, H.; Hoff, L.; Kayran, D.; Kewisch, J.; Lambiase, R.; Lederle, d.; Litvinenko, v.; Mahler, G.; McIntyre, G.; et al.

    2009-05-04

    This paper will present the preliminary results of the testing of the 703 MHz SRF cryomodule designed for use in the ampere class ERL under construction at Brookhaven National Laboratory. The preliminary cavity tests, carried out at Thomas Jefferson Laboratory, demonstrated cavity performance of 20 MV/m with a Qo of 1 x 10{sup 10}, results we expect to reproduce in the horizontal configuration. This test of the entire string assembly will allow us to evaluate all of the additional cryomodule components not previously tested in the VTA and will prepare us for our next milestone test which will be delivery of electrons from our injector through the cryomodule to the beam dump. This will also be the first demonstration of an accelerating cavity designed for use in an ampere class ERL, a key development which holds great promise for future machines.

  14. Studies in the photogalvanic effect in mixed reductants system for solar energy conversion and storage: Dextrose and Ethylenediaminetetraacetic acid-Azur A system

    SciTech Connect (OSTI)

    Gangotri, K.M.; Indora, Vinod

    2010-02-15

    A mixture of two reductants (Dextrose and ethylenediamine tetraacetic acid) is used as a mixed reductants with Azur A as photosensitizer in the photogalvanic cell for solar energy conversion and storage with the aim to reduce the cost of construction for commercial viability. The photogeneration of photopotential and photocurrent were 778.0 mV and 55.0 {mu}A, respectively, whereas maximum power of the cell was 42.79 {mu}W. The observed power at power point of the cell was 10.87 {mu}W and conversion efficiency was 0.1045%.The determined fill factor was 0.1942. The photogalvanic cell so developed can work for 115.0 min in dark where it was irradiated for 175.0 min. A mechanism for the photogeneration of electricity has also been proposed. (author)

  15. Electrocatalytic H2 production with a turnover frequency >107 s?1: The medium provides an increase in rate but not overpotential

    SciTech Connect (OSTI)

    Hou, Jianbo; Fang, Ming; Cardenas, Allan J.; Shaw, Wendy J.; Helm, Monte L.; Bullock, R. Morris; Roberts, John A.; O'Hagan, Molly J.

    2014-11-12

    Exceptionally fast electrocatalytic H2 production (up to 3 x 107 s -1) at overpotentials of ~400 mV are catalysed by [Ni(PPh2NC6H4X2)2]2+ complexes in an acidic ionic liquid - water medium ([(DMF)H]NTf2-H2O, ?H2O = 0.71). This research was supported as part of the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, Office of Basic Energy Sciences and the Office of Science Early Career Research Program through the US DOE, BES (W.J.S.). Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

  16. Role of polycrystallinity in CdTe and CuInSe{sub 2} photovoltaic cells. Annual subcontract report, 1 April 1990--31 March 1991

    SciTech Connect (OSTI)

    Sites, J.R.

    1991-12-31

    The polycrystalline nature of thin-film CdTe and CuInSe{sub 2} solar cells continues to be a major factor in several individual losses that limit overall cell efficiency. This report describes progress in the quantitative separation of these losses, including both measurement and analysis procedures. It also applies these techniques to several individual cells to help document the overall progress with CdTe and CuInSe{sub 2} cells. Notably, CdTe cells from Photon Energy have reduced window photocurrent losses to 1 mA/Cm{sup 2}; those from the University of South Florida have achieved a maximum power voltage of 693 mV; and CuInSe{sub 2} cells from International Solar Electric Technology have shown a hole density as high as 7 {times} 10{sup 16} cm{sup {minus}3}, implying a significant reduction in compensation. 9 refs.

  17. 19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yin, Xingtian; Battaglia, Corsin; Lin, Yongjing; Chen, Kevin; Hettick, Mark; Zheng, Maxwell; Chen, Cheng-Ying; Kiriya, Daisuke; Javey, Ali

    2014-09-25

    We demonstrate an InP heterojunction solar cell employing an ultrathin layer (~10 nm) of amorphous TiO2 deposited at 120°C by atomic layer deposition as the transparent electron-selective contact. The TiO2 film selectively extracts minority electrons from the conduction band of p-type InP while blocking the majority holes due to the large valence band offset, enabling a high maximum open-circuit voltage of 785 mV. Lastly, a hydrogen plasma treatment of the InP surface drastically improves the long-wavelength response of the device, resulting in a high short-circuit current density of 30.5 mA/cm2 and a high power conversion efficiency of 19.2%.

  18. Signal conditioning circuitry design for instrumentation systems.

    SciTech Connect (OSTI)

    Larsen, Cory A.

    2012-01-01

    This report details the current progress in the design, implementation, and validation of the signal conditioning circuitry used in a measurement instrumentation system. The purpose of this text is to document the current progress of a particular design in signal conditioning circuitry in an instrumentation system. The input of the signal conditioning circuitry comes from a piezoresistive transducer and the output will be fed to a 250 ksps, 12-bit analog-to-digital converter (ADC) with an input range of 0-5 V. It is assumed that the maximum differential voltage amplitude input from the sensor is 20 mV with an unknown, but presumably high, sensor bandwidth. This text focuses on a specific design; however, the theory is presented in such a way that this text can be used as a basis for future designs.

  19. Characterization of TLD-100 micro-cubes for use in small field dosimetry

    SciTech Connect (OSTI)

    Peña-Jiménez, Salvador Gamboa-deBuen, Isabel; Lárraga-Gutiérrez, José Manuel E-mail: amanda.garcia.g@gmail.com; García-Garduño, Olivia Amanda E-mail: amanda.garcia.g@gmail.com

    2014-11-07

    At present there are no international regulations for the management of millimeter scale fields and there are no suggestions for a reference detector to perform the characterization and dose determination for unconventional radiation beams (small fields) so that the dosimetry of small fields remains an open research field worldwide because these fields are used in radiotherapy treatments. Sensitivity factors and reproducibility of TLD-100 micro-cubes (1×1×1 mm3) were determinate irradiating the dosimeters with a 6 MV beam in a linear accelerator dedicated to radiosurgery at the Instituto Nacional de Neurología y Neurocirugía (INNN). Thermoluminescent response as a function of dose was determined for doses in water between 0.5 and 3 Gy and two field sizes (2×2 cm2 and 10×10 cm2). It was found that the response is linear over the dose range studied and it does not depend on field size.

  20. Symmetry-dependent electron-electron interaction in coherent tunnel junctions resolved by measurements of zero-bias anomaly

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Liang; Niu, Jiasen; Xiang, Li; Wei, Jian; Li, D. -L.; Feng, J. -F.; Han, X. -F.; Zhang, X. -G.; Coey, J. M. D.

    2014-11-18

    We provide experimental evidence that zero bias anomaly in the differential resistance of magnetic tunnel junctions (MTJs) is due to electron-electron interaction (EEI). Magnon effect is excluded by measuring at low temperatures down to 0.2 K and with reduced AC measurement voltages down to 0.06 mV. The normalized change of conductance is proportional to ln (eV /kB T ), consistent with the Altshuler-Aronov theory of tunneling with EEI but inconsistent with magnetic impurity scattering. The slope of the ln (eV /kBT ) dependence is symmetry dependent, i.e., MTJs with symmetry filtering show di erent slopes for P and AP states,more » while those without symmetry filtering (amorphous barriers) have nearly the same slopes for P and AP.« less

  1. X-band RF Photoinjector for Laser Compton X-ray and Gamma-ray Sources

    SciTech Connect (OSTI)

    Marsh, R. A.; Anderson, G. G.; Anderson, S. G.; Gibson, D. J.; Barty, C. J.

    2015-05-06

    Extremely bright narrow bandwidth gamma-ray sources are expanding the application of accelerator technology and light sources in new directions. An X-band test station has been commissioned at LLNL to develop multi-bunch electron beams. This multi-bunch mode will have stringent requirements for the electron bunch properties including low emittance and energy spread, but across multiple bunches. The test station is a unique facility featuring a 200 MV/m 5.59 cell X-band photogun powered by a SLAC XL4 klystron driven by a Scandinova solid-state modulator. This paper focuses on its current status including the generation and initial characterization of first electron beam. Design and installation of the inverse-Compton scattering interaction region and upgrade paths will be discussed along with future applications.

  2. Amorphous Silicon Carbide Passivating Layers to Enable Higher Processing Temperature in Crystalline Silicon Heterojunction Solar Cells

    SciTech Connect (OSTI)

    Boccard, Mathieu; Holman, Zachary

    2015-04-06

    ) drops from 720 mV to 600 mV when annealing the device at 350°C. Yet, the Voc of devices using an intrinsic a-SiC:H layer with around 10% carbon content in the i/p stack is more resilient to such process, dropping from 710 mV to 690 mV. Also, irrespective of annealing, the slightly improved transparency of a-SiC:H layers allows about 1% current gain due to a better blue-light response. Active-area efficiencies above 20% are thus obtained for particular carbon content conditions, slightly higher than for devices using only a-Si:H. Even for a-SiC:H layers with bandgaps of up to 2.1 eV, good hole collection is maintained (with fill factors of 67% for devices using intrinsic a-SiC:H in the i/p stack, compared to 73% for the reference device). However, S-shaped current-voltage curves were obtained for devices using such a-SiC:H layers in the i/n stack, indicating impeded transport, which would suggest that most of the bandgap increase translates in a conduction-band offset.

  3. Portable radiography system using a relativistic electron beam

    DOE Patents [OSTI]

    Hoeberling, Robert F.

    1990-01-01

    A portable radiographic generator is provided with an explosive magnetic flux compression generator producing the high voltage necessary to generate a relativistic electron beam. The relativistic electron beam is provided with target materials which generates the desired radiographic pulse. The magnetic flux compression generator may require at least two conventional explosively driven generators in series to obtain a desired output voltage of at least 1 MV. The cathode and anode configuration of the diode are selected to provide a switching action wherein a high impedance load is presented to the magnetic flux compression generator when the high voltage is being generated, and thereafter switching to a low impedance load to generate the relativistic electron beam. Magnetic flux compression generators can be explosively driven and provided in a relatively compact, portable form for use with the relativistic x-ray equipment.

  4. Solution-processed amorphous silicon surface passivation layers

    SciTech Connect (OSTI)

    Mews, Mathias Sontheimer, Tobias; Korte, Lars; Rech, Bernd; Mader, Christoph; Traut, Stephan; Wunnicke, Odo

    2014-09-22

    Amorphous silicon thin films, fabricated by thermal conversion of neopentasilane, were used to passivate crystalline silicon surfaces. The conversion is investigated using X-ray and constant-final-state-yield photoelectron spectroscopy, and minority charge carrier lifetime spectroscopy. Liquid processed amorphous silicon exhibits high Urbach energies from 90 to 120?meV and 200?meV lower optical band gaps than material prepared by plasma enhanced chemical vapor deposition. Applying a hydrogen plasma treatment, a minority charge carrier lifetime of 1.37?ms at an injection level of 10{sup 15}/cm{sup 3} enabling an implied open circuit voltage of 724?mV was achieved, demonstrating excellent silicon surface passivation.

  5. Development of an alternating integrator for magnetic measurements for experimental advanced superconducting tokamak

    SciTech Connect (OSTI)

    Liu, D. M. Zhao, W. Z.; He, Y. G.; Chen, B.; Wan, B. N.; Shen, B.; Huang, J.; Liu, H. Q.

    2014-11-15

    A high-performance integrator is one of the key electronic devices for reliably controlling plasma in the experimental advanced superconducting tokamak for long pulse operation. We once designed an integrator system of real-time drift compensation, which has a low integration drift. However, it is not feasible for really continuous operations due to capacitive leakage error and nonlinearity error. To solve the above-mentioned problems, this paper presents a new alternating integrator. In the new integrator, the integrator system of real-time drift compensation is adopted as one integral cell while two such integral cells work alternately. To achieve the alternate function, a Field Programmable Gate Array built in the digitizer is utilized. The performance test shows that the developed integrator with the integration time constant of 20 ms has a low integration drift (<15 mV) for 1000 s.

  6. Neutron physics of the Re/Os clock. II. The (n,n{sup '}) cross section of {sup 187}Os at 30 keV neutron energy

    SciTech Connect (OSTI)

    Mosconi, M.; Heil, M.; Kaeppeler, F.; Plag, R.; Mengoni, A.

    2010-07-15

    The inelastic neutron-scattering cross section of {sup 187}Os has been determined in a time-of-flight experiment at the Karlsruhe 3.7-MV Van de Graaff accelerator. An almost monoenergetic beam of 30-keV neutrons was produced at the threshold of the {sup 7}Li(p,n){sup 7}Be reaction. Information on the inelastic channel is required for reliable calculations of the so-called stellar enhancement factor, by which the laboratory cross section of {sup 187}Os must be corrected in order to account for the thermal population of low-lying excited states at the temperatures of s-process nucleosynthesis, in particular of the important state at 9.75 keV. This correction represents a crucial step in the interpretation of the {sup 187}Os/{sup 187}Re pair as a cosmochronometer.

  7. Cavity Design, Fabrication and Commission Performance of a 750MHz, 4-rod Separator for CEBAF 4-Hall Beam Delivery System

    SciTech Connect (OSTI)

    Wang, Haipeng; Cheng, Guangfeng; Turlington, Larry T.; Wissmann, Mark J.

    2015-09-01

    A short version of the original CEBAF normal conducting 4-rod separator cavity has been developed into a 750MHz one * since the concept of simultaneous 4-hall operation for CEBAF is introduced **. This work has been advanced further based on the EM design optimization, bench measurement and by conducting RF-thermal coupled simulation using CST and ANSYS to confirm the cavity tuning and thermal performance. The cavity fabrication used matured technology like copper plating and machining. The cavity flanges, couplers, tuners and cooling channels adopted consistent/compatible hardware with the existing 500MHz cavities. The electromagnetic and thermal design simulations have greatly reduced the prototyping and bench tuning time of the first prototype. Four production cavities have reached a typical 1.94MV kick voltage or 3.0kW wall loss on each cavity after a minor multipactoring or no processing, 7.5% overhead power than the design specification.

  8. A voltage-gated pore for translocation of tRNA

    SciTech Connect (OSTI)

    Koley, Sandip; Adhya, Samit

    2013-09-13

    Highlights: A tRNA translocating complex was assembled from purified proteins. The complex translocates tRNA at a membrane potential of ?60 mV. Translocation requires Cys and His residues in the FeS center of RIC6 subunit. -- Abstract: Very little is known about how nucleic acids are translocated across membranes. The multi-subunit RNA Import Complex (RIC) from mitochondria of the kinetoplastid protozoon Leishmania tropica induces translocation of tRNAs across artificial or natural membranes, but the nature of the translocation pore remains unknown. We show that subunits RIC6 and RIC9 assemble on the membrane in presence of subunit RIC4A to form complex R3. Atomic Force Microscopy of R3 revealed particles with an asymmetric surface groove of ?20 nm rim diameter and ?1 nm depth. R3 induced translocation of tRNA into liposomes when the pH of the medium was lowered to ?6 in the absence of ATP. R3-mediated tRNA translocation could also be induced at neutral pH by a K{sup +} diffusion potential with an optimum of 6070 mV. Point mutations in the Cys{sub 2}His{sub 2} Fe-binding motif of RIC6, which is homologous to the respiratory Complex III FeS protein, abrogated import induced by low pH but not by K{sup +} diffusion potential. These results indicate that the R3 complex forms a pore that is gated by a proton-generated membrane potential and that the FeS binding region of RIC6 has a role in proton translocation. The tRNA import complex of L. tropica thus contains a novel macromolecular channel distinct from the mitochondrial protein import pore that is apparently involved in tRNA import in some species.

  9. An imaging evaluation of the simultaneously integrated boost breast radiotherapy technique

    SciTech Connect (OSTI)

    Turley, Jessica; Claridge Mackonis, Elizabeth

    2015-09-15

    To evaluate in-field megavoltage (MV) imaging of simultaneously integrated boost (SIB) breast fields to determine its feasibility in treatment verification for the SIB breast radiotherapy technique, and to assess whether the current-imaging protocol and treatment margins are sufficient. For nine patients undergoing SIB breast radiotherapy, in-field MV images of the SIB fields were acquired on days that regular treatment verification imaging was performed. The in-field images were matched offline according to the scar wire on digitally reconstructed radiographs. The offline image correction results were then applied to a margin recipe formula to calculate safe margins that account for random and systematic uncertainties in the position of the boost volume when an offline correction protocol has been applied. After offline assessment of the acquired images, 96% were within the tolerance set in the current department-imaging protocol. Retrospectively performing the maximum position deviations on the Eclipse™ treatment planning system demonstrated that the clinical target volume (CTV) boost received a minimum dose difference of 0.4% and a maximum dose difference of 1.4% less than planned. Furthermore, applying our results to the Van Herk margin formula to ensure that 90% of patients receive 95% of the prescribed dose, the calculated CTV margins were comparable to the current departmental procedure used. Based on the in-field boost images acquired and the feasible application of these results to the margin formula the current CTV-planning target volume margins used are appropriate for the accurate treatment of the SIB boost volume without additional imaging.

  10. TH-C-19A-10: Systematic Evaluation of Photodetectors Performances for Plastic Scintillation Dosimetry

    SciTech Connect (OSTI)

    Boivin, J; Beaulieu, L; Beddar, S; Guillemette, M

    2014-06-15

    Purpose: To assess and compare the performance of different photodetectors likely to be used in a plastic scintillation detector (PSD). Methods: The PSD consists of a 1 mm diameter, 10 mm long plastic scintillation fiber (BCF-60) which is optically coupled to a clear 10 m long optical fiber of the same diameter. A light-tight plastic sheath covers both fibers and the scintillator end is sealed. The clear fiber end is connected to one of the following six studied photodetectors: two polychromatic cameras (one with an optical lens and one with a fiber optic taper replacing the lens); a monochromatic camera with the same optical lens; a PIN photodiode; an avalanche photodiode (APD); and a photomultiplier tube (PMT). Each PSD is exposed to both low energy beams (120, 180, and 220 kVp) from an orthovoltage unit, and high energy beams (6 MV and 23 MV) from a linear accelerator. Various dose rates are explored to identify the photodetectors operating ranges and accuracy. Results: For all photodetectors, the relative uncertainty remains under 5 % for dose rates over 3 mGy/s. The taper camera collects four times more signal than the optical lens camera, although its standard deviation is higher since it could not be cooled. The PIN, APD and PMT have higher sensitivity, suitable for low dose rate and out-of-field dose monitoring. PMT's relative uncertainty remains under 1 % at the lowest dose rate achievable (50 ?Gy/s), suggesting optimal use for live dosimetry. Conclusion: A set of 6 photodetectors have been studied over a broad dose rate range at various energies. For dose rate above 3 mGy/s, the PIN diode is the most effective photodetector in term of performance/cost ratio. For lower dose rate, such as those seen in interventional radiology, PMTs are the optimal choice. FQRNT Doctoral Research Scholarship.

  11. Development of molten-carbonate fuel-cell technology. Final report, February-December 1980

    SciTech Connect (OSTI)

    Not Available

    1980-01-01

    The objective of the work was to focus on the basic technology for producing molten carbonate fuel cell (MCFC) components. This included the development and fabrication of stable anode structures, preparation of lithiated nickel oxide cathodes, synthesis and characterization of a high surface area (gamma-lithium-aluminate) electrolyte support, pressurized cell testing and modeling of the overall electrolyte distribution within a cell to aid performance optimization of the different cell components. The electrode development program is highlighted by two successful 5000 hour bench-scale tests using stabilized anode structures. One of these provided better performance than in any previous state-of-the-art, bench-scale cell (865 mV at 115 mA/cm/sup 2/ under standard conditions). Pressurized testing at 10 atmosphere of a similar stabilized, high surface area, Ni/Co anode structure in a 300 cm/sup 2/ cell showed that the 160 mA/cm/sup 2/ performance goal of 850 mV on low Btu fuel (80% conversion) can be readily met. A study of the H/sub 2/S-effects on molten carbonate fuel cells showed that ERC's Ni/Co anode provided better tolerance than a Ni/Cr anode. Prelithiated nickel oxide plaques were prepared from materials made by a low temperature and a high temperature powder-production process. The methods for fabricating handleable cathodes of various thicknesses were also investigated. In electrolyte matrix development, accelerated out-of-cell and in-cell tests have confirmed the superior stability of ..gamma..-LiAlO/sub 2/.

  12. SU-E-T-308: Systematic Characterization of the Energy Response of Different LiF TLD Crystals for Dosimetry Applications

    SciTech Connect (OSTI)

    Pena, E; Caprile, P; Sanchez-Nieto, B

    2014-06-01

    Purpose: The thermoluminiscense dosimeters (TLDs) are widely used in personal and clinical dosimetry due to its small size, good sensitivity and tissue equivalence, among other advantages. This study presents the characterization of Lithium Fluoride based TLDs, in terms of their absorbed dose response to successive irradiation cycles in a broad range of beam energies, measured under reference conditions. Methods: Four types of Harshaw TLD chips were used: TLD-100, TLD-600 TLD-700 and 100-H. They were irradiated with 10 photon beams of different energy spectrums, from 28 kVp to 18MV (in 30 consecutive cycles for 6 and 18 MV). Results: It was found that the response of the dosimetric system was stabilized (less than ±3%) after 10 cycles for TLD-600 and TLD-700. In the case of TLD-100 and TLD-100H this dependence was not observed. A decreased response to increasing beam energy in terms of absorbed dose to water was observed, as expected, except for TLD-100H which showed the opposite behavior. The less energy dependent detector was the TLD-100H exhibiting a maximum deviation of 12%. The highest variation observed was 33% for TLD-100. The study allowed the determination of calibration factors in absorbed dose for a wide range of energies and materials for different dosimetric applications, such as in-vivo dosimetry during imaging and radiotherapy. Conclusion: The study allowed the determination of calibration factors in absorbed dose for a wide range of energies and materials for different dosimetric applications, such as in-vivo dosimetry during imaging and radiotherapy.

  13. Structural and spectropotentiometric analysis of Blastochloris viridis heterodimer mutant reaction center

    SciTech Connect (OSTI)

    Ponomarenko, Nina S.; Li, Liang; Marino, Antony R.; Tereshko, Valentina; Ostafin, Agnes; Popova, Julia A.; Bylina, Edward J.; Ismagilov, Rustem F.; Norris, Jr., James R.

    2010-07-22

    Heterodimer mutant reaction centers (RCs) of Blastochloris viridis were crystallized using microfluidic technology. In this mutant, a leucine residue replaced the histidine residue which had acted as a fifth ligand to the bacteriochlorophyll (BChl) of the primary electron donor dimer M site (HisM200). With the loss of the histidine-coordinated Mg, one bacteriochlorophyll of the special pair was converted into a bacteriopheophytin (BPhe), and the primary donor became a heterodimer supermolecule. The crystals had dimensions 400 x 100 x 100 {micro}m, belonged to space group P4{sub 3}2{sub 1}2, and were isomorphous to the ones reported earlier for the wild type (WT) strain. The structure was solved to a 2.5 {angstrom} resolution limit. Electron-density maps confirmed the replacement of the histidine residue and the absence of Mg. Structural changes in the heterodimer mutant RC relative to the WT included the absence of the water molecule that is typically positioned between the M side of the primary donor and the accessory BChl, a slight shift in the position of amino acids surrounding the site of the mutation, and the rotation of the M194 phenylalanine. The cytochrome subunit was anchored similarly as in the WT and had no detectable changes in its overall position. The highly conserved tyrosine L162, located between the primary donor and the highest potential heme C{sub 380}, revealed only a minor deviation of its hydroxyl group. Concomitantly to modification of the BChl molecule, the redox potential of the heterodimer primary donor increased relative to that of the WT organism (772 mV vs. 517 mV). The availability of this heterodimer mutant and its crystal structure provides opportunities for investigating changes in light-induced electron transfer that reflect differences in redox cascades.

  14. Poster — Thur Eve — 33: The Influence of a Modeled Treatment Couch on Dose Distributions During IMRT and RapidArc Treatment Delivery

    SciTech Connect (OSTI)

    Aldosary, Ghada; Nobah, Ahmad; Al-Zorkani, Faisal; Moftah, Belal; Devic, Slobodan

    2014-08-15

    Treatment couches have been known to perturb dose delivery in patients. This effect is most pronounced in techniques such as IMRT and RapidArc. Although modern treatment planning systems (TPS) include data for a “default” treatment couch, actual couches are not manufactured identically. Thus, variations in their Hounsfield Unit (HU) values may exist. This study demonstrates a practical and simple method of acquiring reliable HU data for any treatment couch. We also investigate the effects of both the default and modeled treatment couches on absorbed dose. Experimental verifications show that by neglecting to incorporate the treatment couch in the TPS, dose differences of up to 9.5% and 7.3% were present for 4 MV and 10 MV photon beams, respectively. Furthermore, a clinical study based on a cohort of 20 RapidArc and IMRT (brain, pelvis and abdominal) cases is performed. 2D dose distributions show that without the couch in the planning phase, differences ≤ 4.6% and 5.9% for RapidArc and IMRT cases are present for the same cases that the default couch was added to. Additionally, in comparison to the default couch, employing the modeled couch in the calculation process influences dose distributions by ≤ 2.7% and 8% for RapidArc and IMRT cases, respectively. This result was found to be site specific; where an accurate couch proves to be preferable for IMRT brain plans. As such, adding the couch during dose calculation decreases dose calculation errors, and a precisely modeled treatment couch offers higher dose delivery accuracy for brain treatment using IMRT.

  15. SU-E-T-457: Design and Characterization of An Economical 192Ir Hemi-Brain Small Animal Irradiator

    SciTech Connect (OSTI)

    Grams, M; Wilson, Z; Sio, T; Beltran, C; Tryggestad, E; Gupta, S; Blackwell, C; McCollough, K; Sarkaria, J; Furutani, K

    2014-06-01

    Purpose: To describe the design and dosimetric characterization of a simple and economical small animal irradiator. Methods: A high dose rate 192Ir brachytherapy source from a commercially available afterloader was used with a 1.3 centimeter thick tungsten collimator to provide sharp beam penumbra suitable for hemi-brain irradiation of mice. The unit is equipped with continuous gas anesthesia to allow robust animal immobilization. Dosimetric characterization of the device was performed with Gafchromic film. The penumbra from the small animal irradiator was compared under similar collimating conditions to the penumbra from 6 MV photons, 6 MeV electrons, and 20 MeV electrons from a linear accelerator as well as 300 kVp photons from an orthovoltage unit and Monte Carlo simulated 90 MeV protons. Results: The tungsten collimator provides a sharp penumbra suitable for hemi-brain irradiation, and dose rates on the order of 200 cGy/minute were achieved. The sharpness of the penumbra attainable with this device compares favorably to those measured experimentally for 6 MV photons, and 6 and 20 MeV electron beams from a linear accelerator. Additionally, the penumbra was comparable to those measured for a 300 kVp orthovoltage beam and a Monte Carlo simulated 90 MeV proton beam. Conclusions: The small animal irradiator described here can be built for under $1,000 and used in conjunction with any commercial brachytherapy afterloader to provide a convenient and cost-effective option for small animal irradiation experiments. The unit offers high dose rate delivery and sharp penumbra, which is ideal for hemi-brain irradiation of mice. With slight modifications to the design, irradiation of sites other than the brain could be accomplished easily. Due to its simplicity and low cost, the apparatus described is an attractive alternative for small animal irradiation experiments requiring a sharp penumbra.

  16. SU-E-T-235: Monte Carlo Analysis of the Dose Enhancement in the Scalp of Patients Due to Titanium Plate Backscatter During Post-Operative Radiotherapy

    SciTech Connect (OSTI)

    Hardin, M; Elson, H; Lamba, M; Wolf, E; Warnick, R

    2014-06-01

    Purpose: To quantify the clinically observed dose enhancement adjacent to cranial titanium fixation plates during post-operative radiotherapy. Methods: Irradiation of a titanium burr hole cover was simulated using Monte Carlo code MCNPX for a 6 MV photon spectrum to investigate backscatter dose enhancement due to increased production of secondary electrons within the titanium plate. The simulated plate was placed 3 mm deep in a water phantom, and dose deposition was tallied for 0.2 mm thick cells adjacent to the entrance and exit sides of the plate. These results were compared to a simulation excluding the presence of the titanium to calculate relative dose enhancement on the entrance and exit sides of the plate. To verify simulated results, two titanium burr hole covers (Synthes, Inc. and Biomet, Inc.) were irradiated with 6 MV photons in a solid water phantom containing GafChromic MD-55 film. The phantom was irradiated on a Varian 21EX linear accelerator at multiple gantry angles (0–180 degrees) to analyze the angular dependence of the backscattered radiation. Relative dose enhancement was quantified using computer software. Results: Monte Carlo simulations indicate a relative difference of 26.4% and 7.1% on the entrance and exit sides of the plate respectively. Film dosimetry results using a similar geometry indicate a relative difference of 13% and -10% on the entrance and exit sides of the plate respectively. Relative dose enhancement on the entrance side of the plate decreased with increasing gantry angle from 0 to 180 degrees. Conclusion: Film and simulation results demonstrate an increase in dose to structures immediately adjacent to cranial titanium fixation plates. Increased beam obliquity has shown to alleviate dose enhancement to some extent. These results are consistent with clinically observed effects.

  17. Application of a radiophotoluminescent glass plate dosimeter for small field dosimetry

    SciTech Connect (OSTI)

    Aaki, Fujio; Ishidoya, Tatsuya; Ikegami, Tohru; Moribe, Nobuyuki; Yamashita, Yasuyuki

    2005-06-15

    We have recently developed a prototypical radiophotoluminescent glass plate dosimeter (GPD) system as a device for small field dosimetry. The purpose of this study is to examine the usefulness of the GPD system for small field dosimetry. The profiles measured with the GPD were evaluated by comparing them to those from Kodak X-Omat V and GAFCROMIC XR type R film dosimeters for 2, 5, 9, and 15 mm circular collimators created by a linear accelerator-based radiosurgery system. The GPD output factors were compared with those of various detectors including an ion chamber, a p-type silicon diode detector, a glass rod dosimeter (GRD), and a diamond detector. The results measured with the GPD were also confirmed by comparing them to those from Monte Carlo simulations. The accuracy of a simulated beam is validated by the excellent agreement between Monte Carlo calculated and measured central axis depth-dose curves for 9- and 15 mm circular collimators using 4- and 10 MV photon beams. The GPD profiles show almost the same full width at half maximum as those of film dosimeters and Monte Carlo simulations at 4- and 10 MV photon beams, but a little narrower penumbrae than the film dosimeters and Monte Carlo simulations. The output factors measured with the GPD are in good agreement with those from a diode detector, a diamond detector, and the GRD with a small active volume and Monte Carlo simulations, except for a very small 2 mm circular collimator. It was found that the GPD is a very useful detector for small field dosimetry.

  18. Stereotactic, Single-Dose Irradiation of Lung Tumors: A Comparison of Absolute Dose and Dose Distribution Between Pencil Beam and Monte Carlo Algorithms Based on Actual Patient CT Scans

    SciTech Connect (OSTI)

    Chen Huixiao; Lohr, Frank; Fritz, Peter; Wenz, Frederik; Dobler, Barbara; Lorenz, Friedlieb; Muehlnickel, Werner

    2010-11-01

    Purpose: Dose calculation based on pencil beam (PB) algorithms has its shortcomings predicting dose in tissue heterogeneities. The aim of this study was to compare dose distributions of clinically applied non-intensity-modulated radiotherapy 15-MV plans for stereotactic body radiotherapy between voxel Monte Carlo (XVMC) calculation and PB calculation for lung lesions. Methods and Materials: To validate XVMC, one treatment plan was verified in an inhomogeneous thorax phantom with EDR2 film (Eastman Kodak, Rochester, NY). Both measured and calculated (PB and XVMC) dose distributions were compared regarding profiles and isodoses. Then, 35 lung plans originally created for clinical treatment by PB calculation with the Eclipse planning system (Varian Medical Systems, Palo Alto, CA) were recalculated by XVMC (investigational implementation in PrecisePLAN [Elekta AB, Stockholm, Sweden]). Clinically relevant dose-volume parameters for target and lung tissue were compared and analyzed statistically. Results: The XVMC calculation agreed well with film measurements (<1% difference in lateral profile), whereas the deviation between PB calculation and film measurements was up to +15%. On analysis of 35 clinical cases, the mean dose, minimal dose and coverage dose value for 95% volume of gross tumor volume were 1.14 {+-} 1.72 Gy, 1.68 {+-} 1.47 Gy, and 1.24 {+-} 1.04 Gy lower by XVMC compared with PB, respectively (prescription dose, 30 Gy). The volume covered by the 9 Gy isodose of lung was 2.73% {+-} 3.12% higher when calculated by XVMC compared with PB. The largest differences were observed for small lesions circumferentially encompassed by lung tissue. Conclusions: Pencil beam dose calculation overestimates dose to the tumor and underestimates lung volumes exposed to a given dose consistently for 15-MV photons. The degree of difference between XVMC and PB is tumor size and location dependent. Therefore XVMC calculation is helpful to further optimize treatment planning.

  19. SU-E-T-359: Measurement of Various Metrics to Determine Changes in Megavoltage Photon Beam Energy

    SciTech Connect (OSTI)

    Gao, S; Balter, P; Rose, M; Simon, W

    2014-06-01

    Purpose: To examine the relationship between photon beam energy and various metrics for energy on the flattened and flattening filter free (FFF) beams generated by the Varian TrueBeam. Methods: Energy changes were accomplished by adjusting the bending magnet current 10% from the nominal value for the 4, 6, 8, and 10 MV flattened and 6 and 10 MV FFF beams. Profiles were measured for a 3030 cm{sup 2} field using a 2D ionization chamber array and a 3D water Scanner which was also used to measure PDDs. For flattened beams we compared several energy metrics; PDD at 10 cm depth in water (PDD(10)); the variation over the central 80% of the field (Flat); and the average of the highest reading along each diagonal divided by the CAX value, diagonal normalized flatness (FDN). For FFF beams we examined PDD(10), FDN, and the width of a chosen isodose level in a 3030 cm{sup 2} field (W(d%)). Results: Changes in PDD(10) were nearly linear with changes in energy for both flattened and FFF beams as were changes in FDN. Changes in W(d%) were also nearly linear with energy for the FFF beams. PDD(10) was not as sensitive to changes in energy compared to the other metrics for either flattened or FFF beams. Flat was not as sensitive to changes in energy compared to FDN for flattened beams and its behavior depends on depth. FDN was the metric that had the highest sensitivity to the changes in energy for flattened beams while W(d%) was the metric that had highest sensitivity to the changes in energy for FFF beams. Conclusions: The metric FDN was found to be most sensitive to energy changes for flattened beams, while the W(d%) was most sensitive to energy changes for FFF beams.

  20. Normal Conducting CLIC Technology

    SciTech Connect (OSTI)

    Jensen, Erk

    2006-01-03

    The CLIC (Compact Linear Collider) multi-lateral study group based at CERN is studying the technology for an electron-positron linear collider with a centre-of-mass energy up to 5 TeV. In contrast to the International Linear Collider (ILC) study which has chosen to use super-conducting cavities with accelerating gradients in the range of 30-40 MV/m to obtain centre-of-mass collision energies of 0.5-1 TeV, the CLIC study aims to use a normal-conducting system based on two-beam technology with gradients of 150 MV/m. It is generally accepted that this change in technology is not only necessary but the only viable choice for a cost-effective multi-TeV collider. The CLIC study group is studying the technology issues of such a machine, and is in particular developing state-of-the-art 30 GHz molybdenum-iris accelerating structures and power extraction and transfer structures (PETS). The accelerating structure has a new geometry which includes fully-profiled RF surfaces optimised to minimize surface fields, and hybrid damping using both iris slots and radial waveguides. A newly-developed structure-optimisation procedure has been used to simultaneously balance surface fields, power flow, short and long-range transverse wakefields, RF-to-beam efficiency and the ratio of luminosity to input power. The slotted irises allow a simple structure fabrication by high-precision high-speed 3D milling of just four pieces, and an even easier bolted assembly in a vacuum chamber.

  1. SU-E-T-354: Peak Temperature Ratio of TLD Glow Curves to Investigate the Spatial Dependence of LET in a Clinical Proton Beam

    SciTech Connect (OSTI)

    Reft, C [UniversityChicago, Chicago, IL (United States); Pankuch, M; Ramirez, H [ProCure Treatment Centers, Warrenville, IL (United States)

    2014-06-01

    Purpose: Use the ratio of the two high temperature peaks (HTR) in TLD 700 glow curves to investigate spatial dependence of the linear energy transfer (LET) in proton beams. Studies show that the relative biological effectiveness (RBE) depends upon the physical dose as well as its spatial distribution. Although proton therapy uses a spatially invariant RBE of 1.1, studies suggest that the RBE increases in the distal edge of a spread out Bragg peak (SOBP) due to the increased LET. Methods: Glow curve studies in TLD 700 show that the 280 C temperature peak is more sensitive to LET radiation than the 210 C temperature peak. Therefore, the areas under the individual temperature peaks for TLDs irradiated in a proton beam normalized to the peak ratio for 6 MV photons are used to determine the HTR to obtain information on its LET. TLD 700 chips with dimensions 0.310.310.038 cc are irradiated with 90 MeV protons at varying depths in a specially designed blue wax phantom to investigate LET spatial dependence. Results: Five TLDs were placed at five different depths of the percent depth dose curve (PDD) of range 16.2 cm: center of the SOPB and approximately at the 99% distal edge, 90%, 75% and 25% of the PDD, respectively. HTR was 1.3 at the center of the SOBP and varied from 2.2 to 3.9 which can be related to an LET variation from 0.5 to 18 KeV/? via calibration with radiation beams of varying LET. Conclusion: HTR data show a spatially invariant LET slightly greater than the 6 MV radiations in the SOBP, but a rapidly increasing LET at the end of the proton range. These results indicate a spatial variation in RBE with potential treatment consequences when selecting treatment margins to minimize the uncertainties in proton RBE.

  2. TiN coated aluminum electrodes for DC high voltage electron guns

    SciTech Connect (OSTI)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-15

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached −225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ∼22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.

  3. Characterization of MtoD from Sideroxydans lithotrophicus: a cytochrome c electron shuttle used in lithoautotrophic growth

    SciTech Connect (OSTI)

    Beckwith, Christopher R.; Edwards, Marcus J.; Lawes, Matthew; Shi, Liang; Butt, Julea N.; Richardson, David J.; Clarke, Thomas A.

    2015-04-28

    The autotrophic Sideroxydans lithotrophicus ES-1 can grow by coupling the oxidation of ferrous iron to the reduction of oxygen. Soluble ferrous iron is oxidized at the surface of the cell by an MtoAB porin-cytochrome complex that functions as an electron conduit through the outer membrane. Electrons are then transported to the cytoplasmic membrane where they are used to generate proton motive force (PMF) (for ATP synthesis) and NADH for autotrophic processes such as carbon fixation. As part of the mtoAB gene cluster, S. lithotrophicus also contains the gene mtoD that is proposed to encode a cytochrome c protein. We isolated mtoD from a Shewanella oneidensis expression system where the mtoD gene was expressed on a pBAD plasmid vector. Biochemical, biophysical, and crystallographic characterization of the purified MtoD revealed it as an 11 kDa monomeric protein containing a single heme. Sequence and structural alignment indicated that MtoD belonged to the class-1 cytochrome c family and had a similar fold to ferricytochrome c552 family, however the MtoD heme is bis-histidine coordinated and is substantially more exposed than the hemes of other family members. The reduction potential of the MtoD heme at pH 7 was +155 mV vs. Standard Hydrogen Electrode, which is approximately 100 mV lower than that of mitochondrial cytochrome c. Consideration of the properties of MtoD in the context of the potential respiratory partners identified from the genome suggests that MtoD could associate to multiple electron transfer partners as the primary periplasmic electron shuttle.

  4. Characterization of MtoD from Sideroxydans lithotrophicus: a cytochrome c electron shuttle used in lithoautotrophic growth

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Beckwith, Christopher R.; Edwards, Marcus J.; Lawes, Matthew; Shi, Liang; Butt, Julea N.; Richardson, David J.; Clarke, Thomas A.

    2015-04-28

    The autotrophic Sideroxydans lithotrophicus ES-1 can grow by coupling the oxidation of ferrous iron to the reduction of oxygen. Soluble ferrous iron is oxidized at the surface of the cell by an MtoAB porin-cytochrome complex that functions as an electron conduit through the outer membrane. Electrons are then transported to the cytoplasmic membrane where they are used to generate proton motive force (PMF) (for ATP synthesis) and NADH for autotrophic processes such as carbon fixation. As part of the mtoAB gene cluster, S. lithotrophicus also contains the gene mtoD that is proposed to encode a cytochrome c protein. We isolatedmore » mtoD from a Shewanella oneidensis expression system where the mtoD gene was expressed on a pBAD plasmid vector. Biochemical, biophysical, and crystallographic characterization of the purified MtoD revealed it as an 11 kDa monomeric protein containing a single heme. Sequence and structural alignment indicated that MtoD belonged to the class-1 cytochrome c family and had a similar fold to ferricytochrome c552 family, however the MtoD heme is bis-histidine coordinated and is substantially more exposed than the hemes of other family members. The reduction potential of the MtoD heme at pH 7 was +155 mV vs. Standard Hydrogen Electrode, which is approximately 100 mV lower than that of mitochondrial cytochrome c. Consideration of the properties of MtoD in the context of the potential respiratory partners identified from the genome suggests that MtoD could associate to multiple electron transfer partners as the primary periplasmic electron shuttle.« less

  5. Registrations and vehicle miles of travel of light duty vehicles, 1985--1995

    SciTech Connect (OSTI)

    Hu, P.S.; Davis, S.C.; Schmoyer, R.L.

    1998-02-01

    To obtain vehicle registration data that consistently and accurately reflect the distinction between automobiles and light-duty trucks, Oak Ridge National Laboratory (ORNL) was asked by FHWA to estimate the current and historical vehicle registration numbers of automobiles and of other two-axle four-tire vehicles (i.e., light-duty trucks), and their associated travel. The term automobile is synonymous with passenger car. Passenger cars are defined as all sedans, coupes, and station wagons manufactured primarily for the purpose of carrying passengers. This includes taxicabs, rental cars, and ambulances and hearses on an automobile chassis. Light-duty trucks refer to all two-axle four-tire vehicles other than passenger cars. They include pickup trucks, panel trucks, delivery and passenger vans, and other vehicles such as campers, motor homes, ambulances on a truck chassis, hearses on a truck chassis, and carryalls. In this study, light-duty trucks include four major types: (1) pickup truck, (2) van, (3) sport utility vehicle, and (4) other 2-axle 4-tire truck. Specifically, this project re-estimates statistics that appeared in Tables MV-1 and MV-9 of the 1995 Highway Statistics. Given the complexity of the approach developed in this effort and the incompleteness and inconsistency of the state-submitted data, it is recommended that alternatives be considered by FHWA to obtain vehicle registration data. One alternative is the Polk`s NVPP data (via the US Department of Transportation`s annual subscription to Polk). The second alternative is to obtain raw registration files from individual states` Departments of Motor Vehicles and to decode individual VINs.

  6. SU-C-213-05: Evaluation of a Composite Copper-Plastic Material for a 3D Printed Radiation Therapy Bolus

    SciTech Connect (OSTI)

    Vitzthum, L; Ehler, E; Sterling, D; Reynolds, T; Higgins, P; Dusenbery, K

    2015-06-15

    Purpose: To evaluate a novel 3D printed bolus fabricated from a copper-plastic composite as a thin flexible, custom fitting device that can replicate doses achieved with conventional bolus techniques. Methods: Two models of bolus were created on a 3D printer using a composite copper-PLA/PHA. Firstly, boluses were constructed at thicknesses of 0.4, 0.6 and 0.8 mm. Relative dose measurements were performed under the bolus with an Attix Chamber as well as with radiochromic film. Results were compared to superficial Attix Chamber measurements in a water equivalent material to determine the dosimetric water equivalence of the copper-PLA/PHA plastic. Secondly, CT images of a RANDO phantom were used to create a custom fitting bolus across the anterolateral scalp. Surface dose with the bolus placed on the RANDO phantom was measured with radiochromic film at tangential angles with 6, 10, 10 flattening filter free (FFF) and 18 MV photon beams. Results: Mean surface doses for 6, 10, 10FFF and 18 MV were measured as a percent of Dmax for the flat bolus devices of each thickness. The 0.4 mm thickness bolus was determined to be near equivalent to 2.5 mm depth in water for all four energies. Surface doses ranged from 59–63% without bolus and 85–90% with the custom 0.4 mm copper-plastic bolus relative to the prescribed dose for an oblique tangential beam arrangement on the RANDO phantom. Conclusion: Sub-millimeter thickness, 3D printed composite copper-PLA/PHA bolus can provide a build-up effect equivalent to conventional bolus. At this thickness, the 3D printed bolus allows a level of flexure that may provide more patient comfort than current 3D printing materials used in bolus fabrication while still retaining the CT based custom patient shape. Funding provided by an intra-department grant of the University of Minnesota Department of Radiation Oncology.

  7. Topical Non-Invasive Gene Delivery using Gemini Nanoparticles in Interferon-gamma-deficient Mice

    SciTech Connect (OSTI)

    Badea,I.; Wettig, S.; Verrall, R.; Foldvari, M.

    2007-01-01

    Cutaneous gene therapy, although a promising approach for many dermatologic diseases, has not progressed to the stage of clinical trials, mainly due to the lack of an effective gene delivery system. The main objective of this study was to construct and evaluate gemini nanoparticles as a topical formulation for the interferon gamma (IFN-{gamma}) gene in an IFN-{gamma}-deficient mouse model. Nanoparticles based on the gemini surfactant 16-3-16 (NP16-DNA) and another cationic lipid cholesteryl 3{beta}-(-N-[dimethylamino-ethyl] carbamate) [Dc-chol] (NPDc-DNA) were prepared and characterized. Zetasizer measurement indicated a bimodal distribution of 146 and 468 nm average particle sizes for the NP16-DNA ({zeta}-potential +51 mV) nanoparticles and monomodal distribution of 625 nm ({zeta}-potential +44 mV) for the NPDc-DNA. Circular dichroism studies showed that the gemini surfactant compacted the plasmid more efficiently compared to the Dc-chol. Small-angle X-ray scattering measurements revealed structural polymorphism in the NP16-DNA nanoparticles, with lamellar and Fd3m cubic phases present, while for the NPDc-DNA two lamellar phases could be distinguished. In vivo, both topically applied nanoparticles induced higher gene expression compared to untreated control and naked DNA (means of 0.480 and 0.398 ng/cm{sup 2} vs 0.067 and 0.167 ng/cm{sup 2}). However, treatment with NPDc-DNA caused skin irritation, and skin damage, whereas NP16-DNA showed no skin toxicity. In this study, we demonstrated that topical cutaneous gene delivery using gemini surfactant-based nanoparticles in IFN-{gamma}-deficient mice was safe and may provide increased gene expression in the skin due to structural complexity of NP16 nanoparticles (lamellar-cubic phases).

  8. TiN coated aluminum electrodes for DC high voltage electron guns

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-01

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloymore » (Ti-6AI-4V). Following gas conditioning, each TiN-coated aluminum electrode reached -225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ~22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.« less

  9. SU-E-J-204: Radiation Dose to Patients Resulting From Image Guidance Procedures and AAPM TG-180 Update

    SciTech Connect (OSTI)

    Ding, G; Alaei, P

    2014-06-01

    Purpose: Image-guided radiation therapy (IGRT) is the new paradigm for patient positioning and target localization in radiotherapy. Daily imaging procedures add additional dose to the patient's treatment volume and normal tissues and may expose the organs at risk to unaccounted doses. This presentation is to update the progress of AAPM TG-180 which aims to provide strategies to quantify and account the dose from both MV and kV imaging in patient treatment planning. Methods: Our current knowledge on image guidance dose is presented. A summary of doses from image guidance procedures delivered to patients in relationship with therapeutic doses is given. Different techniques in reducing the image guidance dose are summarized. Typical organ doses resulting from different image acquisition procedures used in IGRT are tabulated. Results: Many techniques to reduce the imaging doses are available in clinical applications. There are large variations between dose to bone and dose to soft tissues for x-rays at kilovoltage energy range. Methods for clinical implementation of accounting for the imaging dose from an imaging procedure are available. Beam data from imaging systems can be generated by combining Monte Carlo simulations and experimental measurements for commissioning imaging beams in the treatment planning. Conclusion: The current treatment planning systems are not yet equipped to perform patient specific dose calculations resulting from kV imaging procedures. The imaging dose from current kV image devices has been significantly reduced and is generally much less than that resulting from MV. Because the magnitude of kV imaging dose is significantly low and the variation between patients is modest, it is feasible to estimate dose based on imaging producers or protocols using tabulated values which provides an alternative to accomplish the task of accounting and reporting imaging doses.

  10. Manufacture of SOFC electrodes by wet powder spraying

    SciTech Connect (OSTI)

    Wilkenhoener, R.; Mallener, W.; Buchkremer, H.P.

    1996-12-31

    The reproducible and commercial manufacturing of electrodes with enhanced electrochemical performance is of central importance for a successful technical realization of Solid Oxide Fuel Cell (SOFC) systems. The route of electrode fabrication for the SOFC by Wet Powder Spraying (WPS) is presented. Stabilized suspensions of the powder materials for the electrodes were sprayed onto a substrate by employing a spray gun. After drying of the layers, binder removal and sintering are performed in one step. The major advantage of this process is its applicability for a large variety of materials and its flexibility with regard to layer shape and thickness. Above all, flat or curved substrates of any size can be coated, thus opening up the possibility of {open_quotes}up-scaling{close_quotes} SOFC technology. Electrodes with an enhanced electrochemical performance were developed by gradually optimizing the different process steps. For example an optimized SOFC cathode of the composition La{sub 0.65}Sr{sub 0.3}MnO{sub 3} with 40% 8YSZ showed a mean overpotential of about -50 mV at a current density of -0.8 A/cm{sup 2}, with a standard deviation amounting to 16 mV (950{degrees}C, air). Such optimized electrodes can be manufactured with a high degree of reproducibility, as a result of employing a computer-controlled X-Y system for moving the spray gun. Several hundred sintered composites, comprising the substrate anode and the electrolyte, of 100x 100 mm{sup 2} were coated with the cathode by WPS and used for stack integration. The largest manufactured electrodes were 240x240 mm{sup 2}, and data concerning their thickness homogeneity and electrochemical performance are given.

  11. Physics Division progress report for period ending September 30, 1988

    SciTech Connect (OSTI)

    Livingston, A.B.

    1989-03-01

    This report covers the research and development activities of the Physics Division for the 1988 fiscal year, beginning October 1, 1987, and ending September 30, 1988. The activities of this Division are concentrated in the areas of experimental nuclear physics, experimental atomic physics, and theoretical nuclear and atomic physics. Operation of the Holifield Heavy Ion Research Facility as a national user facility continues to represent the single largest activity within the Division. This year saw the completion of the acceleration tube upgrade of the 25-MV tandem electrostatic accelerator and the achievement of record terminal potentials, operation for an experiment with 25 million volts on terminal, and successful tests with beam at 25.5 MV. The experimental nuclear physics program continues to be dominated by research utilizing heavy ions. These activities, while continuing to center largely on the Holifield Facility, have seen significant growth in the use of facilities that provide intermediate energies and especially ultrarelativistic beams. The UNISOR program, since its inception, has been intimately associated with the Division and, most particularly, with the Holifield Facility. In addition to the Holifield Facility, the Division operates two smaller facilities, the EN Tandem and the ECR Ion Source Facility, as ''User Resources.'' The efforts in theoretical physics, covering both nuclear and atomic physics, are presented. In addition to research with multicharged heavy ions from the ECR source, the effort on atomic physics in support of the controlled fusion program includes a plasma diagnostics development program. The concentration of this program on optical and laser technology is marked by the change in designation to the Laser and Electro-Optics Lab. A small, continuing effort in elementary particle physics, carried out in collaboration with the University of Tennessee, is reported.

  12. Electrodic voltages accompanying stimulated bioremediation of a uranium-contaminated aquifer

    SciTech Connect (OSTI)

    Williams, K.H.; N'Guessan, A.L.; Druhan, J.; Long, P.E.; Hubbard, S.S.; Lovley, D.R.; Banfield, J.F.

    2009-11-15

    The inability to track the products of subsurface microbial activity during stimulated bioremediation has limited its implementation. We used spatiotemporal changes in electrodic potentials (EP) to track the onset and persistence of stimulated sulfate-reducing bacteria in a uranium-contaminated aquifer undergoing acetate amendment. Following acetate injection, anomalous voltages approaching -900 mV were measured between copper electrodes within the aquifer sediments and a single reference electrode at the ground surface. Onset of EP anomalies correlated in time with both the accumulation of dissolved sulfide and the removal of uranium from groundwater. The anomalies persisted for 45 days after halting acetate injection. Current-voltage and current-power relationships between measurement and reference electrodes exhibited a galvanic response, with a maximum power density of 10 mW/m{sup 2} during sulfate reduction. We infer that the EP anomalies resulted from electrochemical differences between geochemically reduced regions and areas having higher oxidation potential. Following the period of sulfate reduction, EP values ranged from -500 to -600 mV and were associated with elevated concentrations of ferrous iron. Within 10 days of the voltage decrease, uranium concentrations rebounded from 0.2 to 0.8 {mu}M, a level still below the background value of 1.5 {mu}M. These findings demonstrate that EP measurements provide an inexpensive and minimally invasive means for monitoring the products of stimulated microbial activity within aquifer sediments and are capable of verifying maintenance of redox conditions favorable for the stability of bioreduced contaminants, such as uranium.

  13. Proof-of-principle demonstration of Nb{sub 3}Sn superconducting radiofrequency cavities for high Q{sub 0} applications

    SciTech Connect (OSTI)

    Posen, S. Liepe, M.; Hall, D. L.

    2015-02-23

    Many future particle accelerators require hundreds of superconducting radiofrequency (SRF) cavities operating with high duty factor. The large dynamic heat load of the cavities causes the cryogenic plant to make up a significant part of the overall cost of the facility. This contribution can be reduced by replacing standard niobium cavities with ones coated with a low-dissipation superconductor such as Nb{sub 3}Sn. In this paper, we present results for single cell cavities coated with Nb{sub 3}Sn at Cornell. Five coatings were carried out, showing that at 4.2 K, high Q{sub 0} out to medium fields was reproducible, resulting in an average quench field of 14 MV/m and an average 4.2 K Q{sub 0} at quench of 8 × 10{sup 9}. In each case, the peak surface magnetic field at quench was well above H{sub c1}, showing that it is not a limiting field in these cavities. The coating with the best performance had a quench field of 17 MV/m, exceeding gradient requirements for state-of-the-art high duty factor SRF accelerators. It is also shown that—taking into account the thermodynamic efficiency of the cryogenic plant—the 4.2 K Q{sub 0} values obtained meet the AC power consumption requirements of state-of-the-art high duty factor accelerators, making this a proof-of-principle demonstration for Nb{sub 3}Sn cavities in future applications.

  14. TiN coated aluminum electrodes for DC high voltage electron guns

    SciTech Connect (OSTI)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-01

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6AI-4V). Following gas conditioning, each TiN-coated aluminum electrode reached -225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ~22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.

  15. COATINGS FOR PROTECTION OF EQUIPMENT FOR BIOCHEMICAL PROCESSING OF GEOTHERMAL RESIDUES: PROGRESS REPORT FY 97

    SciTech Connect (OSTI)

    ALLAN,M.L.

    1997-11-01

    Thermal sprayed ethylene methacrylic acid (EMAA) and ethylene tetrafluoroethylene (ETFE), spray-and-bake ETFE and polyvinylidene fluoride (PVDF) and brushable ceramic-epoxy coatings were evaluated for corrosion protection in a biochemical process to treat geothermal residues. The findings are also relevant to other moderate temperature brine environments where corrosion is a problem. Coupon, Atlas cell, peel strength, cathodic disbondment and abrasion tests were performed in aggressive environments including geothermal sludge, hypersaline brine and sulfur-oxidizing bacteria (Thiobadus ferrooxidans) to determine suitability for protecting storage tanks and reaction vessels. It was found that all of the coatings were resistant to chemical attack and biodegradation at the test temperature of 55 C. The EMAA coatings protected 316L stainless steel from corrosion in coupon tests. However, corrosion of mild steel substrates thermal sprayed with EMAA and ETFE occurred in Atlas cell tests that simulated a lined reactor operating environment and this resulted in decreased adhesive strength. Peel tests to measure residual adhesion revealed that failure mode was dependent on exposure conditions. Long-term tests on the durability of ceramic-epoxy coatings in brine and bacteria are ongoing. Initial indications are that this coating has suitable characteristics. Abrasion tests showed that the ceramic-epoxy had good resistance to the abrasive effects of sludge. Thermal sprayed EMAA coatings also displayed abrasion resistance. Cathodic disbondment tests in brine at room temperature indicated that EMAA coatings are resistant to disbondment at applied potentials of {minus}780 to {minus}1,070 mV SCE for the test conditions and duration. Slight disbondment of one specimen occurred at a potential of {minus}1,500 mV SCE. The EMAA may be suited to use in conjunction with cathodic protection although further long-term, higher temperature testing would be needed.

  16. Coatings for protection of equipment for biochemical processing of geothermal residues: Progress report FY`97

    SciTech Connect (OSTI)

    Allan, M.L.

    1997-11-01

    Thermal sprayed ethylene methacrylic acid (EMAA) and ethylene tetrafluoroethylene (ETFE), spray-and-bake ETFE and polyvinylidene fluoride (PVDF) and brushable ceramic-epoxy coatings were evaluated for corrosion protection in a biochemical process to treat geothermal residues. Coupon, Atlas cell, peel strength, cathodic disbondment and abrasion tests were performed in aggressive environments including geothermal sludge, hypersaline brine and sulfur-oxidizing bacteria (Thiobacillus ferrooxidans) to determine suitability for protecting storage tanks and reaction vessels. It was found that all of the coatings were resistant to chemical attack and biodegradation at the test temperature of 55 C. The EMAA coatings protected 316L stainless steel from corrosion in coupon tests. However, corrosion of mild steel substrates thermal sprayed with EMAA and ETFE occurred in Atlas cell tests that simulated a lined reactor operating environment and this resulted in decreased adhesive strength. Peel tests to measure residual adhesion revealed that failure mode was dependent on exposure conditions. Abrasion tests showed that the ceramic-epoxy had good resistance to the abrasive effects of sludge. Thermal sprayed EMAA coatings also displayed abrasion resistance. Cathodic disbondment tests in brine at room temperature indicated that EMAA coatings are resistant to disbondment at applied potentials of {minus}780 to {minus}1,070 mV SCE for the test conditions and duration. Slight disbondment of one specimen occurred at a potential of {minus}1,500 mV SCE. The EMAA may be suited to use in conjunction with cathodic protection although further long-term, higher temperature testing would be needed.

  17. The role of solvent and the outer coordination sphere on H2 oxidation using [Ni(PCy2NPyz2)2]2+

    SciTech Connect (OSTI)

    Dutta, Arnab; Lense, Sheri J.; Roberts, John A.; Helm, Monte L.; Shaw, Wendy J.

    2015-05-01

    Hydrogenase enzymes are reversible catalysts for H2 production/oxidation, operating with fast rates and minimal overpotentials in water. Many synthetic catalyst mimics of hydrogenase operate in organic solvents. However, recent work has demonstrated the importance of water in the performance of some model complexes. In this work, the H2oxidation activity of [Ni(PCy2N(3pyridazyl)methyl2)2]2+ (CyPyz) was compared as a function of acetonitrile, methanol, and water. The reactivity was compared under neutral and acidic conditions in all three solvents and improvement in catalytic activity, from 2 to 40 s-1, was observed with increasing hydrogen bonding ability of the solvent. In addition, the overpotential for catalysis drops significantly in the presence of acid in all solvents, from as high as 600 mV to as low as 70 mV, primarily due to the shift in the equilibrium potential under these conditions. Finally, H2 production was also observed in the same solution, demonstrating bidirectional (irreversible) homogeneous H2 production/oxidation. A structurally and electronically similar complex with a benzyl instead of a pyridazyl group was not stable under these conditions, limiting the evaluation of the contributions of the outer coordination sphere. Collectively, we show that by tuning conditions we can promote fast, efficient H2 oxidation and bidirectional catalysis.

  18. SU-E-J-49: Design and Fabrication of Custom 3D Printed Phantoms for Radiation Therapy Research and Quality Assurance

    SciTech Connect (OSTI)

    Jenkins, C; Xing, L

    2015-06-15

    Purpose The rapid proliferation of affordable 3D printing techniques has enabled the custom fabrication of items ranging from paper weights to medical implants. This study investigates the feasibility of utilizing the technology for developing novel phantoms for use in radiation therapy quality assurance (QA) procedures. Methods A phantom for measuring the geometric parameters of linear accelerator (LINAC) on-board imaging (OBI) systems was designed using SolidWorks. The design was transferred to a 3D printer and fabricated using a fused deposition modeling (FDM) technique. Fiducials were embedded in the phantom by placing 1.6 mm diameter steel balls in predefined holes and securing them with silicone. Several MV and kV images of the phantom were collected and the visibility and geometric accuracy were evaluated. A second phantom, for use in the experimental evaluation of a high dose rate (HDR) brachytherapy dosimeter, was designed to secure several applicator needles in water. The applicator was fabricated in the same 3D printer and used for experiments. Results The general accuracy of printed parts was determined to be 0.1 mm. The cost of materials for the imaging and QA phantoms were $22 and $5 respectively. Both the plastic structure and fiducial markers of the imaging phantom were visible in MV and kV images. Fiducial marker locations were determined to be within 1mm of desired locations, with the discrepancy being attributed to the fiducial attachment process. The HDR phantom secured the applicators within 0.5 mm of the desired locations. Conclusion 3D printing offers an inexpensive method for fabricating custom phantoms for use in radiation therapy quality assurance. While the geometric accuracy of such parts is limited compared to more expensive methods, the phantoms are still highly functional and provide a unique opportunity for rapid fabrication of custom phantoms for use in radiation therapy QA and research.

  19. Development of high-bandgap AlGaInP solar cells grown by organometallic vapor-phase epitaxy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Perl, Emmett E.; Simon, John; Geisz, John F.; Olavarria, Waldo; Young, Michelle; Duda, Anna; Friedman, Daniel J.; Steiner, Myles A.

    2016-03-29

    AlGaInP solar cells with bandgaps between 1.9 and 2.2 eV are investigated for use in next-generation multijunction photovoltaic devices. This quaternary alloy is of great importance to the development of III-V solar cells with five or more junctions and for cells optimized for operation at elevated temperatures because of the high bandgaps required in these designs. In this work, we explore the conditions for the organometallic vapor-phase epitaxy growth of AlGaInP and study their effects on cell performance. Initial efforts focused on developing ~2.0-eV AlGaInP solar cells with a nominal aluminum composition of 12%. Under the direct spectrum at 1000more » W/m2 (AM1.5D), the best of these samples had an open-circuit voltage of 1.59 V, a bandgap-voltage offset of 440 mV, a fill factor of 88.0%, and an efficiency of 14.8%. We then varied the aluminum composition of the alloy from 0% to 24% and were able to tune the bandgap of the AlGaInP layers from ~1.9 to ~2.2 eV. Furthermore, while the samples with a higher aluminum composition exhibited a reduced quantum efficiency and increased bandgap-voltage offset, the bandgap-voltage offset remained at 500 mV or less, up to a bandgap of ~2.1 eV.« less

  20. SciFri PM: Dosimetry06: Commissioning of a 3D patient specific QA system for hypofractionated prostate treatments

    SciTech Connect (OSTI)

    Rivest, R; Venkataraman, S; McCurdy, B

    2014-08-15

    The objective of this work is to commission the 6MV-SRS beam model in COMPASS (v2.1, IBA-Dosimetry) and validate its use for patient specific QA of hypofractionated prostate treatments. The COMPASS system consists of a 2D ion chamber array (MatriXX{sup Evolution}), an independent gantry angle sensor and associated software. The system can either directly calculate or reconstruct (using measured detector responses) a 3D dose distribution on the patient CT dataset for plan verification. Beam models are developed and commissioned in the same manner as a beam model is commissioned in a standard treatment planning system. Model validation was initially performed by comparing both COMPASS calculations and reconstructions to measured open field beam data. Next, 10 hypofractionated prostate RapidArc plans were delivered to both the COMPASS system and a phantom with ion chamber and film inserted. COMPASS dose distributions calculated and reconstructed on the phantom CT dataset were compared to the chamber and film measurements. The mean ( standard deviation) difference between COMPASS reconstructed dose and ion chamber measurement was 1.4 1.0%. The maximum discrepancy was 2.6%. Corresponding values for COMPASS calculation were 0.9 0.9% and 2.6%, respectively. The average gamma agreement index (3%/3mm) for COMPAS reconstruction and film was 96.7% and 95.3% when using 70% and 20% dose thresholds, respectively. The corresponding values for COMPASS calculation were 97.1% and 97.1%, respectively. Based on our results, COMPASS can be used for the patient specific QA of hypofractionated prostate treatments delivered with the 6MV-SRS beam.

  1. Commissioning the neutron production of a Linac: Development of a simple tool for second cancer risk estimation

    SciTech Connect (OSTI)

    Romero-Expsito, M.; Snchez-Nieto, B.; Terrn, J. A.; Lopes, M. C.; Ferreira, B. C.; Grishchuk, D.; Sandn, C.; Moral-Snchez, S.; Melchor, M.; Domingo, C.; and others

    2015-01-15

    Purpose: Knowing the contribution of neutron to collateral effects in treatments is both a complex and a mandatory task. This work aims to present an operative procedure for neutron estimates in any facility using a neutron digital detector. Methods: The authors previous work established a linear relationship between the total second cancer risk due to neutrons (TR{sup n}) and the number of MU of the treatment. Given that the digital detector also presents linearity with MU, its response can be used to determine the TR{sup n} per unit MU, denoted as m, normally associated to a generic Linac model and radiotherapy facility. Thus, from the number of MU of each patient treatment, the associated risk can be estimated. The feasibility of the procedure was tested by applying it in eight facilities; patients were evaluated as well. Results: From the reading of the detector under selected irradiation conditions, m values were obtained for different machines, ranging from 0.25 10{sup ?4}% per MU for an Elekta Axesse at 10 MV to 6.5 10{sup ?4}% per MU for a Varian Clinac at 18 MV. Using these values, TR{sup n} of patients was estimated in each facility and compared to that from the individual evaluation. Differences were within the range of uncertainty of the authors methodology of equivalent dose and risk estimations. Conclusions: The procedure presented here allows an easy estimation of the second cancer risk due to neutrons for any patient, given the number of MU of the treatment. It will enable the consideration of this information when selecting the optimal treatment for a patient by its implementation in the treatment planning system.

  2. SU-E-T-403: Measurement of the Neutron Ambient Dose Equivalent From the TrueBeam Linac Head and Varian 2100 Clinac

    SciTech Connect (OSTI)

    Harvey, M; Pollard, J; Wen, Z; Gao, S

    2014-06-01

    Purpose: High-energy x-ray therapy produces an undesirable source of stray neutron dose to healthy tissues, and thus, poses a risk for second cancer induction years after the primary treatment. Hence, the purpose of this study was to measure the neutron ambient dose equivalent, H*(10), produced from the TrueBeam and Varian 2100 linac heads, respectively. Of particular note is that there is no measured data available in the literature on H*(10) production from the TrueBeam treatment head. Methods: Both linacs were operated in flattening filter mode using a 15 MV x-ray beam on TrueBeam and an 18 MV x-ray beam for the Varian 2100 Clinac with the jaws and multileaf collimators in the fully closed position. A dose delivery rate of 600 MU/min was delivered on the TrueBeam and the Varian 2100 Clinac, respectively and the H*(10) rate was measured in triplicate using the WENDI-2 detector located at multiple positions including isocenter and longitudinal (gun-target) to the isocenter. Results: For each measurement, the H*(10) rate was relatively constant with increasing distance away from the isocenter with standard deviations on the order of a tenth of a mSv/h or less for the given beam energy. In general, fluctuations in the longitudinal H*(10) rate between the anterior-posterior couch directions were approximately a percent for both beam energies. Conclusion: Our preliminary results suggest an H*(10) rate of about 30 mSv/h (40 mSv/h) or less for TrueBeam (Varian Clinac 2100) for all measurements considered in this study indicating a relatively low contribution of produced secondary neutrons to the primary therapeutic beam.

  3. Review of Evaluation, Measurement and Verification Approaches Used to Estimate the Load Impacts and Effectiveness of Energy Efficiency Programs

    SciTech Connect (OSTI)

    Messenger, Mike; Bharvirkar, Ranjit; Golemboski, Bill; Goldman, Charles A.; Schiller, Steven R.

    2010-04-14

    Efficiency (2007) presented commonly used definitions for EM&V in the context of energy efficiency programs: (1) Evaluation (E) - The performance of studies and activities aimed at determining the effects and effectiveness of EE programs; (2) Measurement and Verification (M&V) - Data collection, monitoring, and analysis associated with the calculation of gross energy and demand savings from individual measures, sites or projects. M&V can be a subset of program evaluation; and (3) Evaluation, Measurement, and Verification (EM&V) - This term is frequently seen in evaluation literature. EM&V is a catchall acronym for determining both the effectiveness of program designs and estimates of load impacts at the portfolio, program and project level. This report is a scoping study that assesses current practices and methods in the evaluation, measurement and verification (EM&V) of ratepayer-funded energy efficiency programs, with a focus on methods and practices currently used for determining whether projected (ex-ante) energy and demand savings have been achieved (ex-post). M&V practices for privately-funded energy efficiency projects (e.g., ESCO projects) or programs where the primary focus is greenhouse gas reductions were not part of the scope of this study. We identify and discuss key purposes and uses of current evaluations of end-use energy efficiency programs, methods used to evaluate these programs, processes used to determine those methods; and key issues that need to be addressed now and in the future, based on discussions with regulatory agencies, policymakers, program administrators, and evaluation practitioners in 14 states and national experts in the evaluation field. We also explore how EM&V may evolve in a future in which efficiency funding increases significantly, innovative mechanisms for rewarding program performance are adopted, the role of efficiency in greenhouse gas mitigation is more closely linked, and programs are increasingly funded from multiple sources

  4. Differential state-dependent modification of rat Na{sub v}1.6 sodium channels expressed in human embryonic kidney (HEK293) cells by the pyrethroid insecticides tefluthrin and deltamethrin

    SciTech Connect (OSTI)

    He, Bingjun; Soderlund, David M.

    2011-12-15

    We expressed rat Na{sub v}1.6 sodium channels in combination with the rat {beta}1 and {beta}2 auxiliary subunits in human embryonic kidney (HEK293) cells and evaluated the effects of the pyrethroid insecticides tefluthrin and deltamethrin on expressed sodium currents using the whole-cell patch clamp technique. Both pyrethroids produced concentration-dependent, resting modification of Na{sub v}1.6 channels, prolonging the kinetics of channel inactivation and deactivation to produce persistent 'late' currents during depolarization and tail currents following repolarization. Both pyrethroids also produced concentration dependent hyperpolarizing shifts in the voltage dependence of channel activation and steady-state inactivation. Maximal shifts in activation, determined from the voltage dependence of the pyrethroid-induced late and tail currents, were {approx} 25 mV for tefluthrin and {approx} 20 mV for deltamethrin. The highest attainable concentrations of these compounds also caused shifts of {approx} 5-10 mV in the voltage dependence of steady-state inactivation. In addition to their effects on the voltage dependence of inactivation, both compounds caused concentration-dependent increases in the fraction of sodium current that was resistant to inactivation following strong depolarizing prepulses. We assessed the use-dependent effects of tefluthrin and deltamethrin on Na{sub v}1.6 channels by determining the effect of trains of 1 to 100 5-ms depolarizing prepulses at frequencies of 20 or 66.7 Hz on the extent of channel modification. Repetitive depolarization at either frequency increased modification by deltamethrin by {approx} 2.3-fold but had no effect on modification by tefluthrin. Tefluthrin and deltamethrin were equally potent as modifiers of Na{sub v}1.6 channels in HEK293 cells using the conditions producing maximal modification as the basis for comparison. These findings show that the actions of tefluthrin and deltamethrin of Na{sub v}1.6 channels in HEK293

  5. Coordination of Retail Demand Response with Midwest ISO Markets

    SciTech Connect (OSTI)

    Bharvirkar, Ranjit; Bharvirkar, Ranjit; Goldman, Charles; Heffner, Grayson; Sedano, Richard

    2008-05-27

    The Organization of Midwest ISO States (OMS) launched the Midwest Demand Resource Initiative (MWDRI) in 2007 to identify barriers to deploying demand response (DR) resources in the Midwest Independent System Operator (MISO) region and develop policies to overcome them. The MWDRI stakeholders decided that a useful initial activity would be to develop more detailed information on existing retail DR programs and dynamic pricing tariffs, program rules, and utility operating practices. This additional detail could then be used to assess any"seams issues" affecting coordination and integration of retail DR resources with MISO's wholesale markets. Working with state regulatory agencies, we conducted a detailed survey of existing DR programs, dynamic pricing tariffs, and their features in MISO states. Utilities were asked to provide information on advance notice requirements to customers, operational triggers used to call events (e.g. system emergencies, market conditions, local emergencies), use of these DR resources to meet planning reserves requirements, DR resource availability (e.g., seasonal, annual), participant incentive structures, and monitoring and verification (M&V) protocols. This report describes the results of this comprehensive survey and discusses policy implications for integrating legacy retail DR programs and dynamic pricing tariffs into organized wholesale markets. Survey responses from 37 MISO members and 4 non-members provided information on 141 DR programs and dynamic pricing tariffs with a peak load reduction potential of 4,727 MW of retail DR resource. Major findings of this study area:- About 72percent of available DR is from interruptible rate tariffs offered to large commercial and industrial customers, while direct load control (DLC) programs account for ~;;18percent. Almost 90percent of the DR resources included in this survey are provided by investor-owned utilities. - Approximately, 90percent of the DR resources are available with less than

  6. Desulfurization of hot fuel gas produced from high-chlorine Illinois coals. Technical report, March 1, 1992--May 31, 1992

    SciTech Connect (OSTI)

    O`Brien, W.S.; Gupta, R.P.

    1992-10-01

    New coal gasification processes are now being developed which can generate electricity with high thermal efficiency either in an integrated gasification combined cycle (IGCC) or in a fuel cell (MCFC). Both of these new coal-to-electricity pathways require that the coal-derived fuel gas be at a high temperature and be free of potential pollutants, such as sulfur compounds. Unfortunately, some high-sulfur Illinois coals also contain significant chlorine which converts into hydrogen chloride (HCl) in the coal-gas. This project investigates the effect of HCl, in concentrations typical of a gasifier fed by high-chlorine Illinois coals, on zinc-titanate sorbents that are currently being developed for H{sub 2}S and COS removal from hot coal gas. This study is designed to identify any deleterious changes in the sorbent caused by the HCI, both in absorptive operation and in the regeneration cycle, and will pave the way to modify the sorbent formulation or the process operating procedure to remove HCl along with the H{sub 2}S and COS from hot coal gas. This will negate any harmful consequences of utilizing high-chlorine Illinois coal in these processes. The work activity during the third quarter of this project involved the performance of the second block-set of experiments in the bench-scale fluidized-bed reactor. These experiments were designed to study the effect of HCl in the desulfurization of a low-Btu fuel gas. Nine single-cycle experiments were performed, at operating temperature of 538, 650, and 750{degrees}C, with HCl concentrations of 0, 200, and 800 ppMv. The presence of HCl in the coal gas significantly enhanced the desulfurization efficacy of the sorbent. A 10-cycle sulfidation-regeneration sequence is currently being performed at 650{degrees}C with 800 ppMv HCl in the simulated fuel gas to determine any adverse effects on the sorbent structure or its desulfurization capability.

  7. TU-F-17A-06: Motion Stability and Dosimetric Impact of Spirometer-Based DIBH-RT of Left-Sided Breast Cancer

    SciTech Connect (OSTI)

    McKenzie, E; Yang, W; Burnison, M; Mirhadi, A; Hakimian, B; Stephen, S; Robert, R; Yue, Y; Sandler, H; Fraass, B

    2014-06-15

    Purpose: Patients undergoing radiotherapy (RT) for left-sided breast cancer have increased risk of coronary artery disease. Deep Inhalation Breath Hold assisted RT (DIBH-RT) is shown to increase the geometric separation of the target area and heart, reducing cardiac radiation dose. The purposes of this study are to use Cine MV portal images to determine the stability of spirometer-guided DIBH-RT and examine the dosimetric cardiopulmonary impact of this technique. Methods: Twenty consecutive patients with left-sided breast cancer were recruited to the IRB-approved study. Free-breathing (FB) and DIBH-CT's were acquired at simulation. Rigid registration of the FB-CT and DIBH-CT was performed using primarily breast tissue. Treatment plans were created for each FB-CT and DIBH-CT using identical paired tangent fields with field-in-field or electronic compensation techniques. Dosimetric evaluation included mean and maximum (Dmax) doses for the left anterior descending artery (LAD), mean heart dose, and left lung V20. Cine MV portal images were acquired for medial and lateral fields during treatment. Analysis of Cine images involved chest wall segmentation using an algorithm developed in-house. Intra- and inter-fractional chest wall motion were determined through affine registration to the first frame of each Cine. Results: Dose to each cardiac structure evaluated was significantly (p<0.001) reduced with the DIBH plans. Mean heart dose decreased from 2.9(0.96.6) to 1.6(0.65.3) Gy; mean LAD dose from 16.6(343.6) to 7.4(1.732.7) Gy; and LAD Dmax from 35.4 (6.153) to 18.4(2.551.2) Gy. No statistically significant reduction was found for the left lung V20. Average AP and SI median chest wall motion (intrafractional) was 0.1 (SD=0.9) and 0.5 (SD=1.1) mm, respectively. Average AP inter-fractional chest wall motion was 2.0 (SD=1.4) mm. Conclusion: Spirometer-based DIBH treatments of the left breast are reproducible both inter- and intra-fractionally, and provide a

  8. Radiation Therapy Risk Factors for Development of Lymphedema in Patients Treated With Regional Lymph Node Irradiation for Breast Cancer

    SciTech Connect (OSTI)

    Chandra, Ravi A.; Miller, Cynthia L.; Skolny, Melissa N.; Warren, Laura E.G.; Horick, Nora; Jammallo, Lauren S.; Sadek, Betro T.; Shenouda, Mina N.; O'Toole, Jean; Specht, Michelle C.; Taghian, Alphonse G.

    2015-03-15

    Purpose: We previously evaluated the risk of breast cancer-related lymphedema (LE) with the addition of regional lymph node irradiation (RLNR) and found an increased risk when RLNR is used. Here we analyze the association of technical radiation therapy (RT) factors in RLNR patients with the risk of LE development. Methods and Materials: From 2005 to 2012, we prospectively screened 1476 women for LE who underwent surgery for breast cancer. Among 1507 breasts treated, 172 received RLNR and had complete technical data for analysis. RLNR was delivered as supraclavicular (SC) irradiation (69% [118 of 172 patients]) or SC plus posterior axillary boost (PAB) (31% [54 of 172]). Bilateral arm volume measurements were performed pre- and postoperatively. Patients' RT plans were analyzed for SC field lateral border (relative to the humeral head), total dose to SC, RT fraction size, beam energy, and type of tangent (normal vs wide). Cox proportional hazards models were used to analyze associated risk factors for LE. Results: Median postoperative follow-up was 29.3 months (range: 4.9-74.1 months). The 2-year cumulative incidence of LE was 22% (95% confidence interval [CI]: 15%-32%) for SC and 20% (95% CI: 11%-37%) for SC plus PAB (SC+PAB). None of the analyzed variables was significantly associated with LE risk (extent of humeral head: P=.74 for <1/3 vs >2/3, P=.41 for 1/3 to 2/3 vs >2/3; P=.40 for fraction size of 1.8 Gy vs 2.0 Gy; P=.57 for beam energy 6 MV vs 10 MV; P=.74 for tangent type wide vs regular; P=.66 for SC vs SC+PAB). Only pretreatment body mass index (hazard ratio [HR]: 1.09; 95% CI: 1.04-1.15, P=.0007) and the use of axillary lymph node dissection (HR: 7.08, 95% CI: 0.98-51.40, P=.05) were associated with risk of subsequent LE development. Conclusions: Of the RT parameters tested, none was associated with an increased risk of LE development. This study underscores the need for future work investigating alternative RLNR risk factors for LE.

  9. Iron Complexes Bearing Diphosphine Ligands with Positioned Pendant Amines as Electrocatalysts for the Oxidation of H2

    SciTech Connect (OSTI)

    Liu, Tianbiao L.; Liao, Qian; O'Hagan, Molly J.; Hulley, Elliott; DuBois, Daniel L.; Bullock, R. Morris

    2015-06-22

    The synthesis and spectroscopic characterization of CpC5F4NFe(PtBu2NBn2)Cl, [3-Cl] (where C5F4N is the tetrafluorpyridyl substituent and PtBu2NBn2 = 1,5-di(tert-butyl)-3,7-di(benzyl)-1,5-diaza-3,7-diphosphacyclooctane) are reported. Complex 3-Cl and previously reported [CpC5F4NFe(PtBu2NtBu2)Cl], 4-Cl, are precursors to intermediates in the catalytic oxidation of H2, including CpC5F4NFe(PtBu2NBn2)H (3-H), CpC5F4NFe(PtBu2NtBu2)H (4-H), [CpC5F4NFe(PtBu2NBn2)]BArF4 ([3](BArF4), [CpC5F4NFe(PtBu2NtBu2)]BArF4 ([4](BArF4), [CpC5F4NFe(PtBu2NBn2)(H2)]BArF4 ([3-H2]BArF4), and [CpC5F4NFe(PtBu2NtBu2H)H]BArF4 ([4-FeH(NH)]BArF4). All of these complexes were characterized by spectroscopic and electrochemical studies; 3-Cl, 3-H and 4-Cl were also characterized by single crystal diffraction studies. 3-H and 4-H are electrocatalysts for H2 (1.0 atm) oxidation in the presence of a excess of the amine base N-methylpyrrolidine, with turnover frequencies at 22 °C of 2.5 s-1 and 0.5 s-1, and overpotentials at Ecat/2 of 235 mV and 95 mV, respectively. Studies of individual chemical and/or electrochemical reactions of the various intermediates provide important insights into the factors governing the overall catalytic activity for H2 oxidation, and provide important insights into the role of the pendant base of the [FeFe] hydrogenase active site. This work was supported by the Center for Molecular Electrocatalysis, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences. Pacific Northwest National Laboratory is operated by Battelle for the U.S. Department of Energy.

  10. Response to high-energy photons of PTW31014 PinPoint ion chamber with a central aluminum electrode

    SciTech Connect (OSTI)

    Agostinelli, S.; Garelli, S.; Piergentili, M.; Foppiano, F.

    2008-07-15

    Since its introduction the PinPoint (PTW-Freiburg) micro-ionization chamber has been proposed for relative dosimetry (output factors, depth dose curves, and beam profiles) as well as for determination of absolute dose of small high-energy photon beams. This paper investigates the dosimetric performance of a new design (type 31014) of the PinPoint ion chamber with a central aluminum electrode. The study included characterization of inherent and radiation-induced leakage, ion collection efficiency and polarity effect, relative response of the chamber, measurement of beam profiles, and depth dose curves. The 6 and 15 MV photon beams of a Varian 2100 C/D were considered. At the nominal operating voltage of 400 V the PinPoint type 31014 chamber was found to present a strong field size dependence of the polarity correction factor and an excess of the collected charge, which can lead to an underestimation of the collection efficiency if determined with the conventional ''two-voltage'' method. In comparison to the original PinPoint design (type 31006) the authors found for type 31014 chamber no overresponse to large-area fields if polarity correction is applied. If no correction is taken into consideration, the authors found the chamber's output to be inaccurate for large-area fields (0.5% accuracy limited up to the 12x12 and 20x20 cm{sup 2} field for the 6 and 15 MV beams, respectively), which is a direct consequence of the stem and polarity effects due to the chamber's very small sensitive volume (0.015 cc) and cable irradiation. Beam profiles and depth dose curves measured with type 31014 PinPoint chamber for small and medium size fields were compared to data measured with a 0.125 cc ion chamber and with high-resolution Kodak EDR2 films. Analysis of the penumbra (80%-20% distance) showed that the spatial resolution of type 31014 PinPoint ion chamber approaches (penumbra broadening {<=}0.6 mm) EDR2 film results.

  11. SU-D-9A-07: Imaging Dose and Cancer Risk in Image-Guided Radiotherapy of Cancers

    SciTech Connect (OSTI)

    Zhou, L; Bai, S; Zhang, Y; Ming, X; Zhang, Y; Deng, J

    2014-06-01

    Purpose: To systematically evaluate the imaging doses and cancer risks associated with various imaging procedures involving ionizing radiation during image-guided radiotherapy of an increasingly large number of cancer patients. Methods: 141 patients (52 brain cases, 47 thoracic cases, 42 abdominal cases, aged 3 to 91 years old) treated between October 2009 and March 2010 were included in this IRB-approved retrospective study. During the whole radiotherapy course, each patient underwent at least one type of imaging procedures, i.e., kV portal, MV portal and kVCBCT, besides CT simulations. Based on Monte Carlo modeling and particle transport in human anatomy of various dimensions, the correlations between the radiation doses to the various organs-at-risk (OARs) at the head, the thoracic and the abdominal regions and one's weight, circumference, scan mAs and kVp have been obtained and used to estimate the radiation dose from a specific imaging procedure. The radiation-induced excess relative risk (ERR) was then estimated with BEIR VII formulism based on one's gender, age and radiation dose. 1+ ERR was reported in this study as relative cancer risk. Results: For the whole cohort of 141 patients, the mean imaging doses from various imaging procedures were 8.3 cGy to the brain, 10.5 cGy to the lungs and 19.2 cGy to the red bone marrow, respectively. Accordingly, the cancer risks were 1.140, 1.369 and 2.671, respectively. In comparison, MV portal deposited largest doses to the lungs while kVCBCT delivered the highest doses to the red bone marrow. Conclusion: The compiled imaging doses to a patient during his/her treatment course were patient-specific and site-dependent, varying from 1.2 to 263.5 cGy on average, which were clinically significant and should be included in the treatment planning and overall decision-making. Our results indicated the necessity of personalized imaging to maximize its clinical benefits while reducing the associated cancer risks. Sichuan

  12. A treatment planning approach to spatially fractionated megavoltage grid therapy for bulky lung cancer

    SciTech Connect (OSTI)

    Costlow, Heather N.; Zhang, Hualin; Das, Indra J.

    2014-10-01

    The purpose of this study was to explore the treatment planning methods of spatially fractionated megavoltage grid therapy for treating bulky lung tumors using multileaf collimator (MLC). A total of 5 patients with lung cancer who had gross tumor volumes ranging from 277 to 635 cm{sup 3} were retrospectively chosen for this study. The tumors were from 6.5 to 9.6 cm at shortest dimension. Several techniques using either electronic compensation or intensity-modulated radiation therapy (IMRT) were used to create a variety of grid therapy plans on the Eclipse treatment planning system. The dose prescription point was calculated to the volume, and a dose of 20 Gy with 6-MV/15-MV beams was used in each plan. The dose-volume histogram (DVH) curves were obtained to evaluate dosimetric characteristics. In addition, DVH curves from a commercially available cerrobend grid collimator were also used for comparison. The linear-quadratic radiobiological response model was used to assess therapeutic ratios (TRs) and equivalent uniform doses (EUD) for all generated plans. A total of 6 different grid therapy plans were created for each patient. Overall, 4 plans had different electronic compensation techniques: Ecomps-Tubes, Ecomps-Circles, Ecomps-Squares, and Ecomps-Weave; the other 2 plans used IMRT and IMRT-Weave techniques. The DVH curves and TRs demonstrated that these MLC-based grid therapy plans can achieve dosimetric properties very similar to those of the cerrobend grid collimator. However, the MLC-based plans have larger EUDs than those with the cerrobend grid collimator. In addition, the field shaping can be performed for targets of any shape in MLC-based plans. Thus, they can deliver a more conformal dose to the targets and spare normal structures better than the cerrobend grid collimator can. The plans generated by the MLC technique demonstrated the advantage over the standard cerrobend grid collimator on accommodating targets and sparing normal structures. Overall, 6

  13. Commercial Building Energy Baseline Modeling Software: Performance Metrics and Method Testing with Open Source Models and Implications for Proprietary Software Testing

    SciTech Connect (OSTI)

    Price, Phillip N.; Granderson, Jessica; Sohn, Michael; Addy, Nathan; Jump, David

    2013-09-01

    The overarching goal of this work is to advance the capabilities of technology evaluators in evaluating the building-level baseline modeling capabilities of Energy Management and Information System (EMIS) software. Through their customer engagement platforms and products, EMIS software products have the potential to produce whole-building energy savings through multiple strategies: building system operation improvements, equipment efficiency upgrades and replacements, and inducement of behavioral change among the occupants and operations personnel. Some offerings may also automate the quantification of whole-building energy savings, relative to a baseline period, using empirical models that relate energy consumption to key influencing parameters, such as ambient weather conditions and building operation schedule. These automated baseline models can be used to streamline the whole-building measurement and verification (M&V) process, and therefore are of critical importance in the context of multi-measure whole-building focused utility efficiency programs. This report documents the findings of a study that was conducted to begin answering critical questions regarding quantification of savings at the whole-building level, and the use of automated and commercial software tools. To evaluate the modeling capabilities of EMIS software particular to the use case of whole-building savings estimation, four research questions were addressed: 1. What is a general methodology that can be used to evaluate baseline model performance, both in terms of a) overall robustness, and b) relative to other models? 2. How can that general methodology be applied to evaluate proprietary models that are embedded in commercial EMIS tools? How might one handle practical issues associated with data security, intellectual property, appropriate testing ‘blinds’, and large data sets? 3. How can buildings be pre-screened to identify those that are the most model-predictable, and therefore those

  14. Validation of heat transfer, thermal decomposition, and container pressurization of polyurethane foam using mean value and Latin hypercube sampling approaches

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Scott, Sarah N.; Dodd, Amanda B.; Larsen, Marvin E.; Suo-Anttila, Jill M.; Erickson, Ken L.

    2014-12-09

    In this study, polymer foam encapsulants provide mechanical, electrical, and thermal isolation in engineered systems. It can be advantageous to surround objects of interest, such as electronics, with foams in a hermetically sealed container in order to protect them from hostile environments or from accidents such as fire. In fire environments, gas pressure from thermal decomposition of foams can cause mechanical failure of sealed systems. In this work, a detailed uncertainty quantification study of polymeric methylene diisocyanate (PMDI)-polyether-polyol based polyurethane foam is presented and compared to experimental results to assess the validity of a 3-D finite element model of themore » heat transfer and degradation processes. In this series of experiments, 320 kg/m3 PMDI foam in a 0.2 L sealed steel container is heated to 1,073 K at a rate of 150 K/min. The experiment ends when the can breaches due to the buildup of pressure. The temperature at key location is monitored as well as the internal pressure of the can. Both experimental uncertainty and computational uncertainty are examined and compared. The mean value method (MV) and Latin hypercube sampling (LHS) approach are used to propagate the uncertainty through the model. The results of the both the MV method and the LHS approach show that while the model generally can predict the temperature at given locations in the system, it is less successful at predicting the pressure response. Also, these two approaches for propagating uncertainty agree with each other, the importance of each input parameter on the simulation results is also investigated, showing that for the temperature response the conductivity of the steel container and the effective conductivity of the foam, are the most important parameters. For the pressure response, the activation energy, effective conductivity, and specific heat are most important. The comparison to experiments and the identification of the drivers of uncertainty allow for

  15. SU-D-18A-02: Towards Real-Time On-Board Volumetric Image Reconstruction for Intrafraction Target Verification in Radiation Therapy

    SciTech Connect (OSTI)

    Xu, X; Iliopoulos, A; Zhang, Y; Pitsianis, N; Sun, X; Yin, F; Ren, L

    2014-06-01

    Purpose: To expedite on-board volumetric image reconstruction from limited-angle kVMV projections for intrafraction verification. Methods: A limited-angle intrafraction verification (LIVE) system has recently been developed for real-time volumetric verification of moving targets, using limited-angle kVMV projections. Currently, it is challenged by the intensive computational load of the prior-knowledge-based reconstruction method. To accelerate LIVE, we restructure the software pipeline to make it adaptable to model and algorithm parameter changes, while enabling efficient utilization of rapidly advancing, modern computer architectures. In particular, an innovative two-level parallelization scheme has been designed: At the macroscopic level, data and operations are adaptively partitioned, taking into account algorithmic parameters and the processing capacity or constraints of underlying hardware. The control and data flows of the pipeline are scheduled in such a way as to maximize operation concurrency and minimize total processing time. At the microscopic level, the partitioned functions act as independent modules, operating on data partitions in parallel. Each module is pre-parallelized and optimized for multi-core processors (CPUs) and graphics processing units (GPUs). Results: We present results from a parallel prototype, where most of the controls and module parallelization are carried out via Matlab and its Parallel Computing Toolbox. The reconstruction is 5 times faster on a data-set of twice the size, compared to recently reported results, without compromising on algorithmic optimization control. Conclusion: The prototype implementation and its results have served to assess the efficacy of our system concept. While a production implementation will yield much higher processing rates by approaching full-capacity utilization of CPUs and GPUs, some mutual constraints between algorithmic flow and architecture specifics remain. Based on a careful analysis of

  16. The first clinical treatment with kilovoltage intrafraction monitoring (KIM): A real-time image guidance method

    SciTech Connect (OSTI)

    Keall, Paul J. O’Brien, Ricky; Huang, Chen-Yu; Aun Ng, Jin; Colvill, Emma; Rugaard Poulsen, Per; Fledelius, Walther; Juneja, Prabhjot; Booth, Jeremy T.; Simpson, Emma; Bell, Linda; Alfieri, Florencia; Eade, Thomas; Kneebone, Andrew

    2015-01-15

    Purpose: Kilovoltage intrafraction monitoring (KIM) is a real-time image guidance method that uses widely available radiotherapy technology, i.e., a gantry-mounted x-ray imager. The authors report on the geometric and dosimetric results of the first patient treatment using KIM which occurred on September 16, 2014. Methods: KIM uses current and prior 2D x-ray images to estimate the 3D target position during cancer radiotherapy treatment delivery. KIM software was written to process kilovoltage (kV) images streamed from a standard C-arm linear accelerator with a gantry-mounted kV x-ray imaging system. A 120° pretreatment kV imaging arc was acquired to build the patient-specific 2D to 3D motion correlation. The kV imager was activated during the megavoltage (MV) treatment, a dual arc VMAT prostate treatment, to estimate the 3D prostate position in real-time. All necessary ethics, legal, and regulatory requirements were met for this clinical study. The quality assurance processes were completed and peer reviewed. Results: During treatment, a prostate position offset of nearly 3 mm in the posterior direction was observed with KIM. This position offset did not trigger a gating event. After the treatment, the prostate motion was independently measured using kV/MV triangulation, resulting in a mean difference of less than 0.6 mm and standard deviation of less than 0.6 mm in each direction. The accuracy of the marker segmentation was visually assessed during and after treatment and found to be performing well. During treatment, there were no interruptions due to performance of the KIM software. Conclusions: For the first time, KIM has been used for real-time image guidance during cancer radiotherapy. The measured accuracy and precision were both submillimeter for the first treatment fraction. This clinical translational research milestone paves the way for the broad implementation of real-time image guidance to facilitate the detection and correction of geometric and

  17. New Surface Radiolabeling Schemes of Super Paramagnetic Iron Oxide Nanoparticles (SPIONs) for Biodistribution Studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nallathamby, Prakash D.; Mortensen, Ninell P.; Palko, Heather A.; Malfatti, Mike; Smith, Catherine; Sonnett, Jim; Doktycz, Mitchel John; Gu, Baohua; Roeder, Ryan; Wang, Wei; et al

    2015-01-01

    Nanomaterial based drug delivery systems allow for the independent tuning of the surface chemical and physical properties that affect their biodistribution in vivo and the therapeutic payloads that they are intended to deliver. Additionally, the added therapeutic and diagnostic value of their inherent material properties often provides extra functionality. Iron based nanomaterials with their magnetic properties and 10 easily tailorable surface chemistry are of particular interest as model systems. In this study the core radius of the iron oxide nanoparticles (NPs) was 14.08 3.92 nm while the hydrodynamic radius of the NPs, as determined by Dynamic Light Scattering (DLS), wasmore » between 90 110 nm. In this study, different approaches were explored to create radiolabeled NPs that are stable in solution. The NPs were functionalized with polycarboxylate or polyamine surface functional groups. Polycarboxylate 15 functionalized NPs had a zeta potential of -35 mV and polyamine functionalized NPs had a zeta potential of +40 mV. The polycarboxylate functionalized NPs were chosen for in vivo biodistribution studies and hence were radiolabeled with 14C, with a final activity of 0.097 nCi/mg-1 of NPs. In chronic studies, the biodistribution profile is tracked using low level radiolabeled proxies of the nanoparticles of interest. Conventionally, these radiolabeled proxies are chemically similar but not chemically identical to the non-20 radiolabeled NPs of interest. This study is novel as different approaches were explored to create radiolabeled NPs that are stable, possess a hydrodynamic radius of <100 nm and most importantly they exhibit an identical surface chemical functionality as their non-radiolabeled counterparts. Identical chemical functionality of the radiolabeled probes to the non-radiolabeled probes was an important consideration to generate statistically similar biodistribution data sets using multiple imaging and 25 detection techniques. The radiolabeling

  18. Intergranular stress corrosion cracking initiation and growth in mill-annealed Alloy 600 tubing in high-temperature caustic

    SciTech Connect (OSTI)

    Brisson, B.W.; Ballinger, R.G.; McIlree, A.R.

    1998-07-01

    Historically, pressurized water reactor (PWR) steam generator (SG) reliability has been dominated by degradation of alloy 600 (UNS N06600) tubing material. Stress corrosion cracking (SCC) crack initiation and crack growth rates (CGR) were measured in mill-annealed alloy 600 (UNS N06600) tubing as a function of the stress intensity factor (K) in 10% caustic at 315 C. Tests were conducted using internally pressurized smooth and precracked tubing. Samples were polarized to 150 mV (precracked tube test) or 225 mV (initiation test) with respect to a nickel electrode. Crack initiation and growth from the external tube surface were monitored using a multifrequency alternating current (AC) potential drop system. The AC potential drop system allowed detection of initiation from a smooth surface as well as the monitoring of crack extension in real time. In the case of precracked sample tests, the sample was precracked in fatigue from a sharp v-notch. CGR were obtained over the K range between 4 MPa{radical}m and 18 MPa{radical}m. Values for K were estimated based upon fractographic analysis of samples after testing and an estimate of the K-solution for a thin-walled tube. Average CGR ranged from 2 mm/y to 14 mm/y. CGR determined in this investigation represent the first SCC CGR data obtained in high-temperature caustic using actual steam generator tubing. Growth rates obtained fell within the overall range of the existing database for CGR (da/dt) in alloy 600. The data and analysis suggested a threshold value of K for K-driven crack growth of {approx} 4 MPa{radical}m. However, since the scatter in existing data is very large and the conditions for most of the data are poorly known or not known at all, this was surprising. More importantly, from the standpoint of life prediction, it was observed that da/dt responded to and was a function of K for cracks as small as 0.2 mm in depth, and probably smaller.

  19. Accuracy of Ultrasound-Based (BAT) Prostate-Repositioning: A Three-Dimensional On-Line Fiducial-Based Assessment With Cone-Beam Computed Tomography

    SciTech Connect (OSTI)

    Boda-Heggemann, Judit Koehler, Frederick Marc; Kuepper, Beate; Wolff, Dirk; Wertz, Hansjoerg; Mai, Sabine; Hesser, Juergen; Lohr, Frank; Wenz, Frederik

    2008-03-15

    Purpose: To assess the accuracy of ultrasound-based repositioning (BAT) before prostate radiation with fiducial-based three-dimensional matching with cone-beam computed tomography (CBCT). Patients and Methods: Fifty-four positionings in 8 patients with {sup 125}I seeds/intraprostatic calcifications as fiducials were evaluated. Patients were initially positioned according to skin marks and after this according to bony structures based on CBCT. Prostate position correction was then performed with BAT. Residual error after repositioning based on skin marks, bony anatomy, and BAT was estimated by a second CBCT based on user-independent automatic fiducial registration. Results: Overall mean value (MV {+-} SD) residual error after BAT based on fiducial registration by CBCT was 0.7 {+-} 1.7 mm in x (group systematic error [M] = 0.5 mm; SD of systematic error [{sigma}] = 0.8 mm; SD of random error [{sigma}] = 1.4 mm), 0.9 {+-} 3.3 mm in y (M = 0.5 mm, {sigma} = 2.2 mm, {sigma} = 2.8 mm), and -1.7 {+-} 3.4 mm in z (M = -1.7 mm, {sigma} = 2.3 mm, {sigma} = 3.0 mm) directions, whereas residual error relative to positioning based on skin marks was 2.1 {+-} 4.6 mm in x (M = 2.6 mm, {sigma} = 3.3 mm, {sigma} = 3.9 mm), -4.8 {+-} 8.5 mm in y (M = -4.4 mm, {sigma} = 3.7 mm, {sigma} = 6.7 mm), and -5.2 {+-} 3.6 mm in z (M = -4.8 mm, {sigma} = 1.7 mm, {sigma} = 3.5mm) directions and relative to positioning based on bony anatomy was 0 {+-} 1.8 mm in x (M = 0.2 mm, {sigma} = 0.9 mm, {sigma} = 1.1 mm), -3.5 {+-} 6.8 mm in y (M = -3.0 mm, {sigma} = 1.8 mm, {sigma} = 3.7 mm), and -1.9 {+-} 5.2 mm in z (M = -2.0 mm, {sigma} = 1.3 mm, {sigma} = 4.0 mm) directions. Conclusions: BAT improved the daily repositioning accuracy over skin marks or even bony anatomy. The results obtained with BAT are within the precision of extracranial stereotactic procedures and represent values that can be achieved with several users with different education levels. If sonographic visibility is insufficient

  20. X-Band Photoinjector Beam Dynamics

    SciTech Connect (OSTI)

    Zhou, Feng; Adolphsen, Chris; Ding, Yuantao; Li, Zenghai; Vlieks, Arnold; /SLAC

    2011-12-13

    SLAC is studying the feasibility of using an X-band RF photocathode gun to produce low emittance bunches for applications such as a mono-energetic MeV {gamma} ray source (in collaboration with LLNL) and a photoinjector for a compact FEL. Beam dynamics studies are being done for a configuration consisting of a 5.5-cell X-band gun followed by several 53-cell high-gradient X-band accelerator structures. A fully 3D program, ImpactT, is used to track particles taking into account space charge forces, short-range longitudinal and transverse wakefields, and the 3D rf fields in the structures, including the quadrupole component of the couplers. The effect of misalignments of the various elements, including the drive-laser, gun, solenoid and accelerator structures, are evaluated. This paper presents these results and estimates of the expected bunch emittance vs cathode gradient, and the effects of mixing between the fundamental and off-frequency longitudinal modes. An X-band gun at SLAC has been shown to operate reliably with a 200 MV/m acceleration gradient at the cathode, which is nearly twice the 115 MV/m acceleration gradient in the LCLS gun. The higher gradient should roughly balance the space charge related transverse emittance growth for the same bunch charge but provide a 3-4 times shorter bunch length. The shorter length would make the subsequent bunch compression easier and allow for a more effective use of emittance exchange. Such a gun can also be used with an X-band linac to produce a compact FEL or g ray source that would require rf sources of only one frequency for beam generation and acceleration. The feasibility of using an X-band rf photocathode gun and accelerator structures to generate high quality electron beams for compact FELs and g ray sources is being studied at SLAC. Results from the X-band photoinjector beam dynamics studies are reported in this paper.

  1. SU-F-BRE-06: Evaluation of Patient CT Dose Reconstruction From 3D Diode Array Measurements Using Anthropomorphic Phantoms

    SciTech Connect (OSTI)

    Huang, M; Benhabib, S; Cardan, R; Brezovich, I; Popple, R; Faught, A; Followill, D

    2014-06-15

    Purpose: To compare 3D reconstructed dose of IMRT plans from 3D diode array measurements with measurements in anthropomorphic phantoms. Methods: Six IMRT plans were created for the IROC Houston (RPC) head and neck (H and N) and lung phantoms following IROC Houston planning protocols. The plans included flattened and unflattened beam energies ranging from 6 MV to 15 MV and both static and dynamic MLC tecH and Niques. Each plan was delivered three times to the respective anthropomorphic phantom, each of which contained thermoluminescent dosimeters (TLDs) and radiochromic films (RCFs). The plans were also delivered to a Delta4 diode array (Scandidos, Uppsala, Sweden). Irradiations were done using a TrueBeam STx (Varian Medical Systems, Palo Alto, CA). The dose in the patient was calculated by the Delta4 software, which used the diode measurements to estimate incident energy fluence and a kernel-based pencil beam algorithm to calculate dose. The 3D dose results were compared with the TLD and RCF measurements. Results: In the lung, the average difference between TLDs and Delta4 calculations was 5% (range 2%7%). For the H and N, the average differences were 2.4% (range 0%4.5%) and 1.1% (range 0%2%) for the high- and low-dose targets, respectively, and 12% (range 10%-13%) for the organ-at-risk simulating the spinal cord. For the RCF and criteria of 7%/4mm, 5%/3mm, and 3%/3mm, the average gamma-index pass rates were 95.4%, 85.7%, and 76.1%, respectively for the H and N and 76.2%, 57.8%, and 49.5% for the lung. The pass-rate in the lung decreased with increasing beam energy, as expected for a pencil beam algorithm. Conclusion: The H and N phantom dose reconstruction met the IROC Houston acceptance criteria for clinical trials; however, the lung phantom dose did not, most likely due to the inaccuracy of the pencil beam algorithm in the presence of low-density inhomogeneities. Work supported by PHS grant CA10953 and CA81647 (NCI, DHHS)

  2. Effect of the L499M mutation of the ascomycetous Botrytis aclada laccase on redox potential and catalytic properties

    SciTech Connect (OSTI)

    Osipov, Evgeny [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); Polyakov, Konstantin [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); Engelhardt Institute of Molecular Biology, Vavilova Str. 32, Moscow 119991 (Russian Federation); Kittl, Roman [BOKU University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien (Austria); Shleev, Sergey [RSC Kurchatov Institute, Acad. Kurchatov Sq. 1, Moscow 123182 (Russian Federation); Malm University, 205 06 Malm (Sweden); Dorovatovsky, Pavel [RSC Kurchatov Institute, Acad. Kurchatov Sq. 1, Moscow 123182 (Russian Federation); Tikhonova, Tamara, E-mail: ttikhonova@inbi.ras.ru [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); Hann, Stephan; Ludwig, Roland [BOKU University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien (Austria); Popov, Vladimir [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); RSC Kurchatov Institute, Acad. Kurchatov Sq. 1, Moscow 123182 (Russian Federation)

    2014-11-01

    The structures of the ascomycetous B. aclada laccase and its L499M T1-site mutant have been solved at 1.7 resolution. The mutant enzyme shows a 140 mV lower redox potential of the type 1 copper and altered kinetic behaviour. The wild type and the mutant have very similar structures, which makes it possible to relate the changes in the redox potential to the L499M mutation Laccases are members of a large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates accompanied by the reduction of dioxygen to water. These enzymes contain four Cu atoms per molecule organized into three sites: T1, T2 and T3. In all laccases, the T1 copper ion is coordinated by two histidines and one cysteine in the equatorial plane and is covered by the side chains of hydrophobic residues in the axial positions. The redox potential of the T1 copper ion influences the enzymatic reaction and is determined by the nature of the axial ligands and the structure of the second coordination sphere. In this work, the laccase from the ascomycete Botrytis aclada was studied, which contains conserved Ile491 and nonconserved Leu499 residues in the axial positions. The three-dimensional structures of the wild-type enzyme and the L499M mutant were determined by X-ray crystallography at 1.7 resolution. Crystals suitable for X-ray analysis could only be grown after deglycosylation. Both structures did not contain the T2 copper ion. The catalytic properties of the enzyme were characterized and the redox potentials of both enzyme forms were determined: E{sub 0} = 720 and 580 mV for the wild-type enzyme and the mutant, respectively. Since the structures of the wild-type and mutant forms are very similar, the change in the redox potential can be related to the L499M mutation in the T1 site of the enzyme.

  3. Quality assurance for the clinical implementation of kilovoltage intrafraction monitoring for prostate cancer VMAT

    SciTech Connect (OSTI)

    Ng, J. A.; Booth, J. T.; OBrien, R. T.; Huang, C.-Y.; Keall, P. J.; Colvill, E.; Poulsen, P. R.

    2014-11-01

    Purpose: Kilovoltage intrafraction monitoring (KIM) is a real-time 3D tumor monitoring system for cancer radiotherapy. KIM uses the commonly available gantry-mounted x-ray imager as input, making this method potentially more widely available than dedicated real-time 3D tumor monitoring systems. KIM is being piloted in a clinical trial for prostate cancer patients treated with VMAT (NCT01742403). The purpose of this work was to develop clinical process and quality assurance (QA) practices for the clinical implementation of KIM. Methods: Informed by and adapting existing guideline documents from other real-time monitoring systems, KIM-specific QA practices were developed. The following five KIM-specific QA tests were included: (1) static localization accuracy, (2) dynamic localization accuracy, (3) treatment interruption accuracy, (4) latency measurement, and (5) clinical conditions accuracy. Tests (1)(4) were performed using KIM to measure static and representative patient-derived prostate motion trajectories using a 3D programmable motion stage supporting an anthropomorphic phantom with implanted gold markers to represent the clinical treatment scenario. The threshold for system tolerable latency is <1 s. The tolerances for all other tests are that both the mean and standard deviation of the difference between the programmed trajectory and the measured data are <1 mm. The (5) clinical conditions accuracy test compared the KIM measured positions with those measured by kV/megavoltage (MV) triangulation from five treatment fractions acquired in a previous pilot study. Results: For the (1) static localization, (2) dynamic localization, and (3) treatment interruption accuracy tests, the mean and standard deviation of the difference are <1.0 mm. (4) The measured latency is 350 ms. (5) For the tests with previously acquired patient data, the mean and standard deviation of the difference between KIM and kV/MV triangulation are <1.0 mm. Conclusions: Clinical process and QA

  4. Investigation of the spatial resolution of an online dose verification device

    SciTech Connect (OSTI)

    Asuni, G.; Rickey, D. W.; McCurdy, B. M. C.

    2012-02-15

    Purpose: The aim of this work is to characterize a new online dose verification device, COMPASS transmission detector array (IBA Dosimetry, Schwarzenbruck, Germany). The array is composed of 1600 cylindrical ionization chambers of 3.8 mm diameter, separated by 6.5 mm center-to-center spacing, in a 40 x 40 arrangement. Methods: The line spread function (LSF) of a single ion chamber in the detector was measured with a narrow slit collimator for a 6 MV photon beam. The 0.25 x 10 mm{sup 2} slit was formed by two machined lead blocks. The LSF was obtained by laterally translating the detector in 0.25 mm steps underneath the slit over a range of 24 mm and taking a measurement at each step. This measurement was validated with Monte Carlo simulation using BEAMnrc and DOSXYZnrc. The presampling modulation transfer function (MTF), the Fourier transform of the line spread function, was determined and compared to calculated (Monte Carlo and analytical) MTFs. Two head-and-neck intensity modulated radiation therapy (IMRT) fields were measured using the device and were used to validate the LSF measurement. These fields were simulated with the BEAMnrc Monte Carlo model, and the Monte Carlo generated incident fluence was convolved with the 2D detector response function (derived from the measured LSF) to obtain calculated dose. The measured and calculated dose distributions were then quantitatively compared using {chi}-comparison criteria of 3% dose difference and 3 mm distance-to-agreement for in-field points (defined as those above the 10% maximum dose threshold). Results: The full width at half-maximum (FWHM) of the measured detector response for a single chamber is 4.3 mm, which is comparable to the chamber diameter of 3.8 mm. The pre-sampling MTF was calculated, and the resolution of one chamber was estimated as 0.25 lp/mm from the first zero crossing. For both examined IMRT fields, the {chi}-comparison between measured and calculated data show good agreement with 95.1% and 96

  5. SU-E-T-631: Commissioning and Comprehensive Evaluation of the ArcCHECK Cylindrical Diode Array for VMAT QA

    SciTech Connect (OSTI)

    Chaswal, V; Weldon, M; Gupta, N; Rong, Y

    2014-06-15

    Purpose: Commissioning and comprehensive evaluation of ArcCHECK phantom for dosimetry of VMAT QA, using 6MV photon beam with and without the flattening filter. Methods: ArcCHECK was evaluated for response dependency on linac dose rate, instantaneous dose rate, radiation field size, beam angle and couch insertion. Scatter dose characterization, consistency and symmetry of response, dosimetric accuracy of fixed aperture arcs and clinical VMAT plans were investigated. Measurements were done using TrueBeam™ STx accelerator (Console version 1.6) with a 6 MV beam with and without flattening filter. Reference dose-grids were calculated using Eclipse TPS Analytical Anisotropic Algorithm (AAA version 10.0.39). Planned doses were calculated using symmetric 2mm 3D dose grids with 4 degree angular resolution defaulted to each control point. Gamma evaluations were performed in absolute dose mode, with default normalization to maximum dose in the curved plane and a low dose threshold of 10% to restrict the analysis to clinically relevant areas. Global and local gamma indices at 3mm/3% and 2mm/2% level were computed using SNC software (version 6.0). Results: Results of gamma analysis demonstrated an overall agreement between ArcCHECK measured and TPS calculated reference doses. Field size dependency was within 0.5% of the reference. Dose-rate based dependency was well within 1% of the TPS reference and the angular dependency was ±3% of the reference, as tested for BEV angles. At the level of 3%/3mm, narrow and wide open arcs as well as clinical VMAT cases demonstrated high level of dosimetry accuracy in global gamma passing rates for both 6X and 6F beams. At the level of 2%/2mm two VMAT cases involving the narrow heavily modulated arcs demonstrated lower passing rates. Conclusion: ArcCHECK phantom with latest software and hardware upgrades is suitable for VMAT QA. For higher sensitivity of 2%/2mm gamma analysis, we intend to use it as one of the VMAT QA evaluation metrics.

  6. Superficial dosimetry imaging based on Čerenkov emission for external beam radiotherapy with megavoltage x-ray beam

    SciTech Connect (OSTI)

    Zhang, Rongxiao; Glaser, Adam K.; Gladstone, David J.; Fox, Colleen J.; Pogue, Brian W.

    2013-10-15

    Purpose: Čerenkov radiation emission occurs in all tissue, when charged particles (either primary or secondary) travel at velocity above the threshold for the Čerenkov effect (about 220 KeV in tissue for electrons). This study presents the first examination of optical Čerenkov emission as a surrogate for the absorbed superficial dose for MV x-ray beams.Methods: In this study, Monte Carlo simulations of flat and curved surfaces were studied to analyze the energy spectra of charged particles produced in different regions near the surfaces when irradiated by MV x-ray beams. Čerenkov emission intensity and radiation dose were directly simulated in voxelized flat and cylindrical phantoms. The sampling region of superficial dosimetry based on Čerenkov radiation was simulated in layered skin models. Angular distributions of optical emission from the surfaces were investigated. Tissue mimicking phantoms with flat and curved surfaces were imaged with a time domain gating system. The beam field sizes (50 × 50–200 × 200 mm{sup 2}), incident angles (0°–70°) and imaging regions were all varied.Results: The entrance or exit region of the tissue has nearly homogeneous energy spectra across the beam, such that their Čerenkov emission is proportional to dose. Directly simulated local intensity of Čerenkov and radiation dose in voxelized flat and cylindrical phantoms further validate that this signal is proportional to radiation dose with absolute average discrepancy within 2%, and the largest within 5% typically at the beam edges. The effective sampling depth could be tuned from near 0 up to 6 mm by spectral filtering. The angular profiles near the theoretical Lambertian emission distribution for a perfect diffusive medium, suggesting that angular correction of Čerenkov images may not be required even for curved surface. The acquisition speed and signal to noise ratio of the time domain gating system were investigated for different acquisition procedures, and the

  7. PERI - Auto-tuning Memory Intensive Kernels for Multicore

    SciTech Connect (OSTI)

    Bailey, David H; Williams, Samuel; Datta, Kaushik; Carter, Jonathan; Oliker, Leonid; Shalf, John; Yelick, Katherine; Bailey, David H

    2008-06-24

    We present an auto-tuning approach to optimize application performance on emerging multicore architectures. The methodology extends the idea of search-based performance optimizations, popular in linear algebra and FFT libraries, to application-specific computational kernels. Our work applies this strategy to Sparse Matrix Vector Multiplication (SpMV), the explicit heat equation PDE on a regular grid (Stencil), and a lattice Boltzmann application (LBMHD). We explore one of the broadest sets of multicore architectures in the HPC literature, including the Intel Xeon Clovertown, AMD Opteron Barcelona, Sun Victoria Falls, and the Sony-Toshiba-IBM (STI) Cell. Rather than hand-tuning each kernel for each system, we develop a code generator for each kernel that allows us to identify a highly optimized version for each platform, while amortizing the human programming effort. Results show that our auto-tuned kernel applications often achieve a better than 4X improvement compared with the original code. Additionally, we analyze a Roofline performance model for each platform to reveal hardware bottlenecks and software challenges for future multicore systems and applications.

  8. Experimental and Monte Carlo evaluation of Eclipse treatment planning system for effects on dose distribution of the hip prostheses

    SciTech Connect (OSTI)

    atl?, Serap; Tan?r, Gne?

    2013-10-01

    The present study aimed to investigate the effects of titanium, titanium alloy, and stainless steel hip prostheses on dose distribution based on the Monte Carlo simulation method, as well as the accuracy of the Eclipse treatment planning system (TPS) at 6 and 18 MV photon energies. In the present study the pencil beam convolution (PBC) method implemented in the Eclipse TPS was compared to the Monte Carlo method and ionization chamber measurements. The present findings show that if high-Z material is used in prosthesis, large dose changes can occur due to scattering. The variance in dose observed in the present study was dependent on material type, density, and atomic number, as well as photon energy; as photon energy increased back scattering decreased. The dose perturbation effect of hip prostheses was significant and could not be predicted accurately by the PBC method for hip prostheses. The findings show that for accurate dose calculation the Monte Carlo-based TPS should be used in patients with hip prostheses.

  9. A hybrid DNA-templated gold nanocluster for enhanced enzymatic reduction of oxygen

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chakraborty, Saumen; Babanova, Sofia; Rocha, Reginaldo C.; Desireddy, Anil; Artyushkova, Kateryna; Boncella, Amy E.; Atanassov, Plamen; Martinez, Jennifer S.

    2015-08-19

    We report the synthesis and characterization of a new DNA-templated gold nanocluster (AuNC) of ~1 nm in diameter and possessing ~7 Au atoms. When integrated with bilirubin oxidase (BOD) and single walled carbon nanotubes (SWNTs), the AuNC acts as an enhancer of electron transfer (ET) and lowers the overpotential of electrocatalytic oxygen reduction reaction (ORR) by ~15 mV as compared to the enzyme alone. In addition, the presence of AuNC causes significant enhancements in the electrocatalytic current densities at the electrode. Control experiments show that such enhancement of ORR by the AuNC is specific to nanoclusters and not to plasmonicmore » gold particles. Rotating ring disk electrode (RRDE) measurements confirm 4e– reduction of O2 to H2O with minimal production of H2O2, suggesting that the presence of AuNC does not perturb the mechanism of ORR catalyzed by the enzyme. This unique role of the AuNC as enhancer of ET at the enzyme-electrode interface makes it a potential candidate for the development of cathodes in enzymatic fuel cells, which often suffer from poor electronic communication between the electrode surface and the enzyme active site. In conclusion, the AuNC displays phosphorescence with large Stokes shift and microsecond lifetime.« less

  10. A hybrid DNA-templated gold nanocluster for enhanced enzymatic reduction of oxygen

    SciTech Connect (OSTI)

    Chakraborty, Saumen; Babanova, Sofia; Rocha, Reginaldo C.; Desireddy, Anil; Artyushkova, Kateryna; Boncella, Amy E.; Atanassov, Plamen; Martinez, Jennifer S.

    2015-08-19

    We report the synthesis and characterization of a new DNA-templated gold nanocluster (AuNC) of ~1 nm in diameter and possessing ~7 Au atoms. When integrated with bilirubin oxidase (BOD) and single walled carbon nanotubes (SWNTs), the AuNC acts as an enhancer of electron transfer (ET) and lowers the overpotential of electrocatalytic oxygen reduction reaction (ORR) by ~15 mV as compared to the enzyme alone. In addition, the presence of AuNC causes significant enhancements in the electrocatalytic current densities at the electrode. Control experiments show that such enhancement of ORR by the AuNC is specific to nanoclusters and not to plasmonic gold particles. Rotating ring disk electrode (RRDE) measurements confirm 4e– reduction of O2 to H2O with minimal production of H2O2, suggesting that the presence of AuNC does not perturb the mechanism of ORR catalyzed by the enzyme. This unique role of the AuNC as enhancer of ET at the enzyme-electrode interface makes it a potential candidate for the development of cathodes in enzymatic fuel cells, which often suffer from poor electronic communication between the electrode surface and the enzyme active site. In conclusion, the AuNC displays phosphorescence with large Stokes shift and microsecond lifetime.

  11. Ultrahigh surface area carbon from carbonated beverages. Combining self-templaing process and in situ activation

    SciTech Connect (OSTI)

    Zhang, Pengfei; Zhang, Zhiyong; Chen, Jihua; Dai, Sheng

    2015-05-11

    Ultrahigh surface area carbons (USACs, e.g., >2000 m2/g) are attracting tremendous attention due to their outstanding performance in energy-related applications. The state-of-art approaches to USACs involve templating or activation methods and all these techniques show certain drawbacks. In this work, a series of USACs with specific surface areas up to 3633 m2/g were prepared in two steps: hydrothermal carbonization (200 °C) of carbonated beverages (CBs) and further thermal treatment in nitrogen (600–1000 °C). The rich inner porosity is formed by a self-templated process during which acids and polyelectrolyte sodium salts in the beverage formulas make some contribution. This strategy covers various CBs such as Coca Cola®, Pepsi Cola®, Dr. Pepper®, andFanta® and it enables an acceptable product yield (based on sugars), for example: 21 wt% for carbon (2940 m2/g) from Coca Cola®. Being potential electrode materials for supercapacitors, those carbon materials possessed a good specific capacitance (57.2–185.7 F g-1) even at a scan rate of 1000 mV s-1. Thus, a simple and efficient strategy to USACs has been presented.

  12. Modeling and simulation of a beam emission spectroscopy diagnostic for the ITER prototype neutral beam injector

    SciTech Connect (OSTI)

    Barbisan, M. Zaniol, B.; Pasqualotto, R.

    2014-11-15

    A test facility for the development of the neutral beam injection system for ITER is under construction at Consorzio RFX. It will host two experiments: SPIDER, a 100 keV H{sup −}/D{sup −} ion RF source, and MITICA, a prototype of the full performance ITER injector (1 MV, 17 MW beam). A set of diagnostics will monitor the operation and allow to optimize the performance of the two prototypes. In particular, beam emission spectroscopy will measure the uniformity and the divergence of the fast particles beam exiting the ion source and travelling through the beam line components. This type of measurement is based on the collection of the H{sub α}/D{sub α} emission resulting from the interaction of the energetic particles with the background gas. A numerical model has been developed to simulate the spectrum of the collected emissions in order to design this diagnostic and to study its performance. The paper describes the model at the base of the simulations and presents the modeled H{sub α} spectra in the case of MITICA experiment.

  13. Enhanced piezoelectric output voltage and Ohmic behavior in Cr-doped ZnO nanorods

    SciTech Connect (OSTI)

    Sinha, Nidhi; Ray, Geeta; Godara, Sanjay; Gupta, Manoj K.; Kumar, Binay

    2014-11-15

    Highlights: • Low cost highly crystalline Cr-doped ZnO nanorods were synthesized. • Enhancement in dielectric, piezoelectric and ferroelectric properties were observed. • A high output voltage was obtained in AFM. • Cr-doping resulted in enhanced conductivity and better Ohmic behavior in ZnO/Ag contact. - Abstract: Highly crystalline Cr-doped ZnO nanorods (NRs) were synthesized by solution technique. The size distribution was analyzed by high resolution tunneling electron microscope (HRTEM) and particle size analyzer. In atomic force microscope (AFM) studies, peak to peak 8 mV output voltage was obtained on the application of constant normal force of 25 nN. It showed high dielectric constant (980) with phase transition at 69 °C. Polarization vs. electric field (P–E) loops with remnant polarization (6.18 μC/cm{sup 2}) and coercive field (0.96 kV/cm) were obtained. In I–V studies, Cr-doping was found to reduce the rectifying behavior in the Ag/ZnO Schottky contact which is useful for field effect transistor (FET) and solar cell applications. With these excellent properties, Cr-doped ZnO NRs can be used in nanopiezoelectronics, charge storage and ferroelectric applications.

  14. Photoelectrochemistry of Semiconductor Nanowire Arrays

    SciTech Connect (OSTI)

    Mallouk, Thomas E; Redwing, Joan M

    2009-11-10

    This project supported research on the growth and photoelectrochemical characterization of semiconductor nanowire arrays, and on the development of catalytic materials for visible light water splitting to produce hydrogen and oxygen. Silicon nanowires were grown in the pores of anodic aluminum oxide films by the vapor-liquid-solid technique and were characterized electrochemically. Because adventitious doping from the membrane led to high dark currents, silicon nanowire arrays were then grown on silicon substrates. The dependence of the dark current and photovoltage on preparation techniques, wire diameter, and defect density was studied for both p-silicon and p-indium phosphide nanowire arrays. The open circuit photovoltage of liquid junction cells increased with increasing wire diameter, reaching 350 mV for micron-diameter silicon wires. Liquid junction and radial p-n junction solar cells were fabricated from silicon nano- and microwire arrays and tested. Iridium oxide cluster catalysts stabilized by bidentate malonate and succinate ligands were also made and studied for the water oxidation reaction. Highlights of this project included the first papers on silicon and indium phosphide nanowire solar cells, and a new procedure for making ligand-stabilized water oxidation catalysts that can be covalently linked to molecular photosensitizers or electrode surfaces.

  15. Production data on 0.55 eV InGaAs thermophotovoltaic cells

    SciTech Connect (OSTI)

    Wojtzuk, S.; Colter, P.; Charache, G.; Campbell, B.

    1996-05-01

    Low bandgap 0.55 eV (2.25 {micro}m cutoff wavelength) indium gallium arsenide (In{sub 0.72}Ga{sub 0.28}As) thermophotovoltaic (TPV) cells use much more of the long wavelength energy emitted from low temperature (< 1,200 C) thermal sources than either Si or GaSb cells. Data are presented on a statistically significant number (2,500) of these TPV cells, indicating the performance obtainable in large numbers of cells. This data should be useful in the design and modeling of TPV system performance. At 1.2 A/cm{sup 2} short-circuit current, an average open-circuit voltage of 283 mV is obtained with a 60% fill factor. The peak external quantum efficiency for uncoated cells is 65% and is over 50% from 1.1 to 2.2 {micro}m. Internal quantum efficiency is over 76% in this range assuming an estimated 34% reflectance loss.

  16. Neutrino Physics from the Cosmic Microwave Background and Large Scale Structure

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abazajian, K. N.; Arnold, K.; Austermann, J.; Benson, B. A.; Bischoff, C.; Bock, J.; Bond, J. R.; Borrill, J.; Calabrese, E.; Carlstrom, J. E.; et al

    2014-03-15

    This is a report on the status and prospects of the quantification of neutrino properties through the cosmological neutrino background for the Cosmic Frontier of the Division of Particles and Fields Community Summer Study long-term planning exercise. Experiments planned and underway are prepared to study the cosmological neutrino background in detail via its influence on distance-redshift relations and the growth of structure. The program for the next decade described in this document, including upcoming spectroscopic galaxy surveys eBOSS and DESI and a new Stage-IV CMB polarization experiment CMB-S4, will achieve σ (σmv) = 16 meV and σ (Neff)(Neff) = 0.020.more » Such a mass measurement will produce a high significance detection of non-zero σmνσmν, whose lower bound derived from atmospheric and solar neutrino oscillation data is about 58 meV. If neutrinos have a minimal normal mass hierarchy, this measurement will definitively rule out the inverted neutrino mass hierarchy, shedding light on one of the most puzzling aspects of the Standard Model of particle physics — the origin of mass. This precise a measurement of Neff will allow for high sensitivity to any light and dark degrees of freedom produced in the big bang and a precision test of the standard cosmological model prediction that Neff = 3.046.« less

  17. Spectrographic temperature measurement of a high power breakdown arc in a high pressure gas switch

    SciTech Connect (OSTI)

    Yeckel, Christopher; Curry, Randy

    2011-09-15

    A procedure for obtaining an approximate temperature value of conducting plasma generated during self-break closure of a RIMFIRE gas switch is described. The plasma is in the form of a breakdown arc which conducts approximately 12 kJ of energy in 1 {mu}s. A spectrographic analysis of the trigger-section of the 6-MV RIMFIRE laser triggered gas switch used in Sandia National Laboratory's ''Z-Machine'' has been made. It is assumed that the breakdown plasma has sufficiently approached local thermodynamic equilibrium allowing a black-body temperature model to be applied. This model allows the plasma temperature and radiated power to be approximated. The gas dielectric used in these tests was pressurized SF{sub 6}. The electrode gap is set at 4.59 cm for each test. The electrode material is stainless steel and insulator material is poly(methyl methacrylate). A spectrum range from 220 to 550 nanometers has been observed and calibrated using two spectral irradiance lamps and three spectrograph gratings. The approximate plasma temperature is reported.

  18. High capacitance of coarse-grained carbide derived carbon electrodes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dyatkin, Boris; Gogotsi, Oleksiy; Malinovskiy, Bohdan; Zozulya, Yuliya; Simon, Patrice; Gogotsi, Yury

    2016-01-01

    Here, we report exceptional electrochemical properties of supercapacitor electrodes composed of large, granular carbide-derived carbon (CDC) particles. We synthesized 70–250 μm sized particles with high surface area and a narrow pore size distribution, using a titanium carbide (TiC) precursor. Electrochemical cycling of these coarse-grained powders defied conventional wisdom that a small particle size is strictly required for supercapacitor electrodes and allowed high charge storage densities, rapid transport, and good rate handling ability. Moreover, the material showcased capacitance above 100 F g-1 at sweep rates as high as 250 mV s-1 in organic electrolyte. 250–1000 micron thick dense CDC films withmore » up to 80 mg cm-2 loading showed superior areal capacitances. The material significantly outperformed its activated carbon counterpart in organic electrolytes and ionic liquids. Furthermore, large internal/external surface ratio of coarse-grained carbons allowed the resulting electrodes to maintain high electrochemical stability up to 3.1 V in ionic liquid electrolyte. In addition to presenting novel insights into the electrosorption process, these coarse-grained carbons offer a pathway to low-cost, high-performance implementation of supercapacitors in automotive and grid-storage applications.« less

  19. Integrated digital inverters based on two-dimensional anisotropic ReS₂ field-effect transistors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Erfu; Fu, Yajun; Wang, Yaojia; Feng, Yanqing; Liu, Huimei; Wan, Xiangang; Zhou, Wei; Wang, Baigeng; Shao, Lubin; Ho, Ching -Hwa; et al

    2015-05-07

    Semiconducting two-dimensional transition metal dichalcogenides are emerging as top candidates for post-silicon electronics. While most of them exhibit isotropic behaviour, lowering the lattice symmetry could induce anisotropic properties, which are both scientifically interesting and potentially useful. Here we present atomically thin rhenium disulfide (ReS₂) flakes with unique distorted 1T structure, which exhibit in-plane anisotropic properties. We fabricated monolayer and few-layer ReS₂ field-effect transistors, which exhibit competitive performance with large current on/off ratios (~10⁷) and low subthreshold swings (100 mV per decade). The observed anisotropic ratio along two principle axes reaches 3.1, which is the highest among all known two-dimensional semiconductingmore » materials. Furthermore, we successfully demonstrated an integrated digital inverter with good performance by utilizing two ReS₂ anisotropic field-effect transistors, suggesting the promising implementation of large-scale two-dimensional logic circuits. Our results underscore the unique properties of two-dimensional semiconducting materials with low crystal symmetry for future electronic applications.« less

  20. Catalytic activity in lithium-treated core–shell MoOx/MoS2 nanowires

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Cummins, Dustin R.; Martinez, Ulises; Kappera, Rajesh; Voiry, Damien; Martinez-Garcia, Alejandro; Jasinski, Jacek; Kelly, Dan; Chhowalla, Manish; Mohite, Aditya D.; Sunkara, Mahendra K.; et al

    2015-09-22

    Significant interest has grown in the development of earth-abundant and efficient catalytic materials for hydrogen generation. Layered transition metal dichalcogenides present opportunities for efficient electrocatalytic systems. Here, we report the modification of 1D MoOx/MoS2 core–shell nanostructures by lithium intercalation and the corresponding changes in morphology, structure, and mechanism of H2 evolution. The 1D nanowires exhibit significant improvement in H2 evolution properties after lithiation, reducing the hydrogen evolution reaction (HER) onset potential by ~50 mV and increasing the generated current density by ~600%. The high electrochemical activity in the nanowires results from disruption of MoS2 layers in the outer shell, leadingmore » to increased activity and concentration of defect sites. This is in contrast to the typical mechanism of improved catalysis following lithium exfoliation, i.e., crystal phase transformation. As a result, these structural changes are verified by a combination of Raman and X-ray photoelectron spectroscopy (XPS).« less