National Library of Energy BETA

Sample records for beam time esaf

  1. Beam Stability Complaint Form

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

    For New Users For Current Users For Administrators MX Users APS User Portal APS Data Management Practices Find a Beamline Apply for Beam Time ESAF Contacts Calendars User...

  2. Web-Based ESAF System FAQs

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

    Documentation of the Web-Based ESAF System. What is new in the Web ESAF process? (662012) Do all Beamlines use the APS web system? How does the process work? How do I submit a...

  3. Apply for Beam Time | Advanced Photon Source

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

    All About Proposals Users Home Apply for Beam Time Deadlines Proposal Types Concepts, Definitions, and Help My APS Portal My APS Portal Apply for Beam Time Next Proposal Deadline...

  4. Monitoring external beam radiotherapy using real-time beam visualization

    SciTech Connect (OSTI)

    Jenkins, Cesare H.; Naczynski, Dominik J.; Yu, Shu-Jung S.; Xing, Lei

    2015-01-15

    Purpose: To characterize the performance of a novel radiation therapy monitoring technique that utilizes a flexible scintillating film, common optical detectors, and image processing algorithms for real-time beam visualization (RT-BV). Methods: Scintillating films were formed by mixing Gd{sub 2}O{sub 2}S:Tb (GOS) with silicone and casting the mixture at room temperature. The films were placed in the path of therapeutic beams generated by medical linear accelerators (LINAC). The emitted light was subsequently captured using a CMOS digital camera. Image processing algorithms were used to extract the intensity, shape, and location of the radiation field at various beam energies, dose rates, and collimator locations. The measurement results were compared with known collimator settings to validate the performance of the imaging system. Results: The RT-BV system achieved a sufficient contrast-to-noise ratio to enable real-time monitoring of the LINAC beam at 20 fps with normal ambient lighting in the LINAC room. The RT-BV system successfully identified collimator movements with sub-millimeter resolution. Conclusions: The RT-BV system is capable of localizing radiation therapy beams with sub-millimeter precision and tracking beam movement at video-rate exposure.

  5. Time Structure of the LANSCE Beam

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

    The proton beam is delivered to Target-1 after passing through the proton storage ring (PSR). The time it takes an 800 MeV proton to travel one circuit of the PSR is 360 ns. The...

  6. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, Craig L. (Albuquerque, NM)

    1987-01-01

    A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  7. Short rise time intense electron beam generator

    DOE Patents [OSTI]

    Olson, C.L.

    1984-03-16

    A generator for producing an intense relativisitc electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

  8. Method and apparatus for timing of laser beams in a multiple laser beam fusion system

    DOE Patents [OSTI]

    Eastman, Jay M. (Pittsford, NY); Miller, Theodore L. (Rochester, NY)

    1981-01-01

    The optical path lengths of a plurality of comparison laser beams directed to impinge upon a common target from different directions are compared to that of a master laser beam by using an optical heterodyne interferometric detection technique. The technique consists of frequency shifting the master laser beam and combining the master beam with a first one of the comparison laser beams to produce a time-varying heterodyne interference pattern which is detected by a photo-detector to produce an AC electrical signal indicative of the difference in the optical path lengths of the two beams which were combined. The optical path length of this first comparison laser beam is adjusted to compensate for the detected difference in the optical path lengths of the two beams. The optical path lengths of all of the comparison laser beams are made equal to the optical path length of the master laser beam by repeating the optical path length adjustment process for each of the comparison laser beams. In this manner, the comparison laser beams are synchronized or timed to arrive at the target within .+-.1.times.10.sup.-12 second of each other.

  9. Beam Time Request - Radiation Effects Facility / Cyclotron Institute /

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

    Texas A&M University Beam-Time Request Information about scheduling beam-time: HOURLY RATE: Contact Henry Clark, 979-845-1411 or clark@comp.tamu.edu MINIMUM BILLING: There is an eight hour minimum billing, after that you are billed for time used including tuning time. CANCELLATION POLICY: If you schedule cyclotron time and need to cancel at a later date, you must notify Henry Clark two weeks prior to the start date to avoid the cancellation fee. The fee is in the amount of one half of

  10. Inverse time-of-flight spectrometer for beam plasma research

    SciTech Connect (OSTI)

    Yushkov, Yu. G., E-mail: yuyushkov@gmail.com; Zolotukhin, D. B.; Tyunkov, A. V. [Tomsk State University of Control Systems and Radioelectronics, 40 Lenin Ave., Tomsk 634050 (Russian Federation); Oks, E. M. [Tomsk State University of Control Systems and Radioelectronics, 40 Lenin Ave., Tomsk 634050 (Russian Federation); Institute of High Current Electronics SB RAS, 2/3, Akademichesky Ave., Tomsk 634055 (Russian Federation); Savkin, K. P. [Institute of High Current Electronics SB RAS, 2/3, Akademichesky Ave., Tomsk 634055 (Russian Federation)

    2014-08-15

    The paper describes the design and principle of operation of an inverse time-of-flight spectrometer for research in the plasma produced by an electron beam in the forevacuum pressure range (520 Pa). In the spectrometer, the deflecting plates as well as the drift tube and the primary ion beam measuring system are at high potential with respect to ground. This provides the possibility to measure the mass-charge constitution of the plasma created by a continuous electron beam with a current of up to 300 mA and electron energy of up to 20 keV at forevacuum pressures in the chamber placed at ground potential. Research results on the mass-charge state of the beam plasma are presented and analyzed.

  11. Radial electron-beam-breakup transit-time oscillator

    DOE Patents [OSTI]

    Kwan, Thomas J. T. (Los Alamos, NM); Mostrom, Michael A. (Albuquerque, NM)

    1998-01-01

    A radial electron-beam-breakup transit-time oscillator (RBTO) provides a compact high power microwave generator. The RBTO includes a coaxial vacuum transmission line having an outer conductor and an inner conductor. The inner conductor defines an annular cavity with dimensions effective to support an electromagnetic field in a TEM.sub.00m mode. A radial field emission cathode is formed on the outer conductor for providing an electron beam directed toward the annular cavity electrode. Microwave energy is then extracted from the annular cavity electrode.

  12. Time-delayed directional beam phased array antenna

    DOE Patents [OSTI]

    Fund, Douglas Eugene; Cable, John William; Cecil, Tony Myron

    2004-10-19

    An antenna comprising a phased array of quadrifilar helix or other multifilar antenna elements and a time-delaying feed network adapted to feed the elements. The feed network can employ a plurality of coaxial cables that physically bridge a microstrip feed circuitry to feed power signals to the elements. The cables provide an incremental time delay which is related to their physical lengths, such that replacing cables having a first set of lengths with cables having a second set of lengths functions to change the time delay and shift or steer the antenna's main beam. Alternatively, the coaxial cables may be replaced with a programmable signal processor unit adapted to introduce the time delay using signal processing techniques applied to the power signals.

  13. A real-time intercepting beam-profile monitor for a medical cyclotron

    SciTech Connect (OSTI)

    Hendriks, C.; Uittenbosch, T.; Cameron, D.; Kellogg, S.; Gray, D.; Buckley, K.; Schaffer, P.; Verzilov, V.; Hoehr, C.

    2013-11-15

    There is a lack of real-time continuous beam-diagnostic tools for medical cyclotrons due to high power deposition during proton irradiation. To overcome this limitation, we have developed a profile monitor that is capable of providing continuous feedback about beam shape and current in real time while it is inserted in the beam path. This enables users to optimize the beam profile and observe fluctuations in the beam over time with periodic insertion of the monitor.

  14. Time domain analysis of a gyrotron traveling wave amplifier with misaligned electron beam

    SciTech Connect (OSTI)

    Wang, Qiushi Peng, Shuyuan; Luo, Jirun

    2014-08-15

    This article develops a time-domain theory to study the beam-wave interaction in gyrotron traveling wave amplifier (gyro-TWA) with a misaligned electron beam. The effects of beam misalignment on the TE{sub 01} mode gyro-TWA operating at the fundamental are discussed. Numerical results show that the effect of misalignment is less obvious when the input power is larger, and the influences of misalignment on the stable gain and the stable time are basically opposite.

  15. Method and apparatus for real time imaging and monitoring of radiotherapy beams

    DOE Patents [OSTI]

    Majewski, Stanislaw (Yorktown, VA); Proffitt, James (Newport News, VA); Macey, Daniel J. (Birmingham, AL); Weisenberger, Andrew G. (Yorktown, VA)

    2011-11-01

    A method and apparatus for real time imaging and monitoring of radiation therapy beams is designed to preferentially distinguish and image low energy radiation from high energy secondary radiation emitted from a target as the result of therapeutic beam deposition. A detector having low sensitivity to high energy photons combined with a collimator designed to dynamically image in the region of the therapeutic beam target is used.

  16. Fidelity of a Time-Resolved Imaging Diagnostic for Electron Beam Profiles

    SciTech Connect (OSTI)

    Frayer, Daniel; Ekdahl, Carl A.; Johnson, Douglas

    2014-10-01

    An optical tomographic diagnostic instrument has been fielded at the Dual-Axis Radiographic Hydrodynamic Test Facility at Los Alamos National Laboratory. Four optical lines of sight create projections of an image of an electron beam on a Cerenkov target, which are relayed via optical fiber to streak cameras. From these projections, a reconstruction algorithm creates time histories of the beams cross section. The instrument was fielded during and after facility commissioning, and tomographic reconstructions reported beam parameters. Results from reconstructions and analysis are noted.

  17. Heavy ion beam probe operation in time va

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

    operation in time varying equilibria of improved confinement reversed field pinch discharges D. R. Demers, X. Chen, P. M. Schoch, and P. J. Fimognari Citation: Rev. Sci. Instrum. 81, 10E109 (2010); doi: 10.1063/1.3479109 View online: http://dx.doi.org/10.1063/1.3479109 View Table of Contents: http://rsi.aip.org/resource/1/RSINAK/v81/i10 Published by the American Institute of Physics. Additional information on Rev. Sci. Instrum. Journal Homepage: http://rsi.aip.org Journal Information:

  18. Time-dependent simulation of prebunched one and two-beam free electron laser

    SciTech Connect (OSTI)

    Mirian, N. S.; Maraghechi, B.

    2014-04-15

    A numerical simulation in one-dimension is conducted to study the slippage effects on prebunched free electron laser. A technique for the simulation of time dependent free electron lasers (FEL) to model the slippage effects is introduced, and the slowly varying envelope approximation in both z and t is used to illustrate the temporal behaviour in the prebunched FEL. Slippage effect on prebunched two-beam FEL is compared with the one-beam modeling. The evaluation of the radiation pulse energy, thermal and phase distribution, and radiation pulse shape in one-beam and two-beam modeling is studied. It was shown that the performance is considerably undermined when the slippage time is comparable to the pulse duration. However, prebunching reduces the slippage. Prebunching also leads to the radiation pulse with a single smooth spike.

  19. Vacuum Performance and Beam Life Time in the PEP-II Storage Rings

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: Vacuum Performance and Beam Life Time in the PEP-II Storage Rings Citation Details In-Document Search Title: Vacuum Performance and Beam Life Time in the PEP-II Storage Rings × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources

  20. Characterization of beam dynamics in the APS injector rings using time-resolved imaging techniques

    SciTech Connect (OSTI)

    Yang, B.X.; Lumpkin, A.H.; Borland, M.

    1997-06-01

    Images taken with streak cameras and gated intensified cameras with both time (longitudinal) and spatial (transverse) resolution reveal a wealth of information about circular accelerators. The authors illustrate a novel technique by a sequence of dual-sweep streak camera images taken at a high dispersion location in the booster synchrotron, where the horizontal coordinate is strongly correlated with the particle energy and the {open_quotes}top-view{close_quotes} of the beam gives a good approximation to the particle density distribution in the longitudinal phase space. A sequence of top-view images taken fight after injection clearly shows the beam dynamics in the phase space. We report another example from the positron accumulator ring for the characterization of its beam compression bunching with the 12th harmonic rf.

  1. Registration of clinical volumes to beams-eye-view images for real-time tracking

    SciTech Connect (OSTI)

    Bryant, Jonathan H.; Rottmann, Joerg; Lewis, John H.; Mishra, Pankaj; Berbeco, Ross I.; Keall, Paul J.

    2014-12-15

    Purpose: The authors combine the registration of 2D beams eye view (BEV) images and 3D planning computed tomography (CT) images, with relative, markerless tumor tracking to provide automatic absolute tracking of physician defined volumes such as the gross tumor volume (GTV). Methods: During treatment of lung SBRT cases, BEV images were continuously acquired with an electronic portal imaging device (EPID) operating in cine mode. For absolute registration of physician-defined volumes, an intensity based 2D/3D registration to the planning CT was performed using the end-of-exhale (EoE) phase of the four dimensional computed tomography (4DCT). The volume was converted from Hounsfield units into electron density by a calibration curve and digitally reconstructed radiographs (DRRs) were generated for each beam geometry. Using normalized cross correlation between the DRR and an EoE BEV image, the best in-plane rigid transformation was found. The transformation was applied to physician-defined contours in the planning CT, mapping them into the EPID image domain. A robust multiregion method of relative markerless lung tumor tracking quantified deviations from the EoE position. Results: The success of 2D/3D registration was demonstrated at the EoE breathing phase. By registering at this phase and then employing a separate technique for relative tracking, the authors are able to successfully track target volumes in the BEV images throughout the entire treatment delivery. Conclusions: Through the combination of EPID/4DCT registration and relative tracking, a necessary step toward the clinical implementation of BEV tracking has been completed. The knowledge of tumor volumes relative to the treatment field is important for future applications like real-time motion management, adaptive radiotherapy, and delivered dose calculations.

  2. Using time separation of signals to obtain independent proton and antiproton beam position measurements around the Tevatron

    SciTech Connect (OSTI)

    Webber, R.; /Fermilab

    2005-05-01

    Independent position measurement of the counter-circulating proton and antiproton beams in the Tevatron, never supported by the original Tevatron Beam Position Monitor (BPM) system, presents a challenge to upgrading that system. This paper discusses the possibilities and complications of using time separation of proton and antiproton signals at the numerous BPM locations and for the dynamic Tevatron operating conditions. Results of measurements using one such method are presented.

  3. Energy spread and time structure of ion beams extracted from the ReA-EBIT rare isotope charge breeder

    SciTech Connect (OSTI)

    Baumann, Thomas M.; Lapierre, Alain; Schwarz, Stefan; Kittimanapun, Kritsada; Bollen, Georg

    2015-01-09

    The ReA re-accelerator of the National Superconducting Cyclotron Laboratory at Michigan State University utilizes an Electron Beam Ion Trap (EBIT) for charge breeding thermalized rare isotope beams. Recent commissioning measurements have been performed to characterize the performance of this EBIT. The energy spread of extracted highly charged ion beams was measured to be about 0.3% of the total beam energy. From this, the temperature of the ion ensemble in the trap is calculated to be kT{sub q}/q?=?31eV for O{sup 7+}, while it is kT{sub q}/q?=?25eV for K{sup 15+}. In addition initial results are presented for two extraction schemes developed to spread highly charged ion pulses in time.

  4. Time of Decline in Sexual Function After External Beam Radiotherapy for Prostate Cancer

    SciTech Connect (OSTI)

    Siglin, Joshua; Kubicek, Gregory J.; Leiby, Benjamin; Valicenti, Richard K.

    2010-01-15

    Purpose: Erectile dysfunction is one of the most concerning toxicities for patients in the treatment of prostate cancer. The inconsistent evaluation of sexual function (SF) and limited follow-up data have necessitated additional study to clarify the rate and timing of erectile dysfunction after external beam radiotherapy (EBRT) for prostate cancer. Methods and Materials: A total of 143 men completed baseline data on SF before treatment and at the subsequent follow-up visits. A total of 1187 validated SF inventories were analyzed from the study participants. Multiple domains of SF (sex drive, erectile function, ejaculatory function, and overall satisfaction) were analyzed for <=8 years of follow-up. Results: The median follow-up was 4.03 years. The strongest predictor of SF after EBRT was SF before treatment. For all domains of SF, the only statistically significant decrease in function occurred in the first 24 months after EBRT. SF stabilized 2 years after treatment completion, with no statistically significant change in any area of SF >2 years after the end of EBRT. Conclusion: These data suggest that SF does not have a continuous decline after EBRT. Instead, SF decreases maximally within the first 24 months after EBRT, with no significant changes thereafter.

  5. Beam Transport

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

    Beam Transport Beam Transport A simplified drawing of the beam transport system from the linac to Target-1 (Lujan Center), Target-2 (Blue Room) and Target-4 is shown below. In usual operation beam is transported from the linac through the pulsed Ring Injection Kicker (RIKI) magnet. When RIKI is switched on, the beam is injected into the storage ring with the time structure shown here. The beam is accumulated in the PSR and then transported to Target-1. beam_transport1 Simplified drawing of the

  6. Optical eye tracking system for real-time noninvasive tumor localization in external beam radiotherapy

    SciTech Connect (OSTI)

    Via, Riccardo Fassi, Aurora; Fattori, Giovanni; Fontana, Giulia; Pella, Andrea; Tagaste, Barbara; Ciocca, Mario; Riboldi, Marco; Baroni, Guido; Orecchia, Roberto

    2015-05-15

    Purpose: External beam radiotherapy currently represents an important therapeutic strategy for the treatment of intraocular tumors. Accurate target localization and efficient compensation of involuntary eye movements are crucial to avoid deviations in dose distribution with respect to the treatment plan. This paper describes an eye tracking system (ETS) based on noninvasive infrared video imaging. The system was designed for capturing the tridimensional (3D) ocular motion and provides an on-line estimation of intraocular lesions position based on a priori knowledge coming from volumetric imaging. Methods: Eye tracking is performed by localizing cornea and pupil centers on stereo images captured by two calibrated video cameras, exploiting eye reflections produced by infrared illumination. Additionally, torsional eye movements are detected by template matching in the iris region of eye images. This information allows estimating the 3D position and orientation of the eye by means of an eye local reference system. By combining ETS measurements with volumetric imaging for treatment planning [computed tomography (CT) and magnetic resonance (MR)], one is able to map the position of the lesion to be treated in local eye coordinates, thus enabling real-time tumor referencing during treatment setup and irradiation. Experimental tests on an eye phantom and seven healthy subjects were performed to assess ETS tracking accuracy. Results: Measurements on phantom showed an overall median accuracy within 0.16 mm and 0.40° for translations and rotations, respectively. Torsional movements were affected by 0.28° median uncertainty. On healthy subjects, the gaze direction error ranged between 0.19° and 0.82° at a median working distance of 29 cm. The median processing time of the eye tracking algorithm was 18.60 ms, thus allowing eye monitoring up to 50 Hz. Conclusions: A noninvasive ETS prototype was designed to perform real-time target localization and eye movement monitoring during ocular radiotherapy treatments. The device aims at improving state-of-the-art invasive procedures based on surgical implantation of radiopaque clips and repeated acquisition of X-ray images, with expected positive effects on treatment quality and patient outcome.

  7. Time-of-flight energy analyzer for the plasma potential measurements by a heavy ion beam diagnostic

    SciTech Connect (OSTI)

    Nedzelskiy, I.S.; Malaquias, A.; Goncalves, B.; Silva, C.; Varandas, C.A.F.; Cabral, J.A.C.

    2004-10-01

    A time-of-flight (TOF) technique for the plasma potential measurements by a heavy ion beam diagnostic (HIBD) with a multiple cell array detector has been elaborated on tokamak ISTTOK as an alternative to the traditional electrostatic energy analyzer. This article describes the design and operation of a four-channel TOF energy analyzer (TOFEA). First results of plasma potential measurements by TOFEA are presented proving the feasibility of this technique in experiments with HIBD.

  8. A split-beam probe-pump-probe scheme for femtosecond time resolved protein X-ray crystallography

    SciTech Connect (OSTI)

    van Thor, Jasper J.; Madsen, Anders

    2015-01-01

    In order to exploit the femtosecond pulse duration of X-ray Free-Electron Lasers (XFEL) operating in the hard X-ray regime for ultrafast time-resolved protein crystallography experiments, critical parameters that determine the crystallographic signal-to-noise (I/σI) must be addressed. For single-crystal studies under low absorbed dose conditions, it has been shown that the intrinsic pulse intensity stability as well as mode structure and jitter of this structure, significantly affect the crystallographic signal-to-noise. Here, geometrical parameters are theoretically explored for a three-beam scheme: X-ray probe, optical pump, X-ray probe (or “probe-pump-probe”) which will allow experimental determination of the photo-induced structure factor amplitude differences, ΔF, in a ratiometric manner, thereby internally referencing the intensity noise of the XFEL source. In addition to a non-collinear split-beam geometry which separates un-pumped and pumped diffraction patterns on an area detector, applying an additional convergence angle to both beams by focusing leads to integration over mosaic blocks in the case of well-ordered stationary protein crystals. Ray-tracing X-ray diffraction simulations are performed for an example using photoactive yellow protein crystals in order to explore the geometrical design parameters which would be needed. The specifications for an X-ray split and delay instrument that implements both an offset angle and focused beams are discussed, for implementation of a probe-pump-probe scheme at the European XFEL. We discuss possible extension of single crystal studies to serial femtosecond crystallography, particularly in view of the expected X-ray damage and ablation due to the first probe pulse.

  9. A split-beam probe-pump-probe scheme for femtosecond time resolved protein X-ray crystallography

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

    van Thor, Jasper J.; Madsen, Anders

    2015-01-01

    In order to exploit the femtosecond pulse duration of X-ray Free-Electron Lasers (XFEL) operating in the hard X-ray regime for ultrafast time-resolved protein crystallography experiments, critical parameters that determine the crystallographic signal-to-noise (I/σI) must be addressed. For single-crystal studies under low absorbed dose conditions, it has been shown that the intrinsic pulse intensity stability as well as mode structure and jitter of this structure, significantly affect the crystallographic signal-to-noise. Here, geometrical parameters are theoretically explored for a three-beam scheme: X-ray probe, optical pump, X-ray probe (or “probe-pump-probe”) which will allow experimental determination of the photo-induced structure factor amplitude differences, ΔF,more » in a ratiometric manner, thereby internally referencing the intensity noise of the XFEL source. In addition to a non-collinear split-beam geometry which separates un-pumped and pumped diffraction patterns on an area detector, applying an additional convergence angle to both beams by focusing leads to integration over mosaic blocks in the case of well-ordered stationary protein crystals. Ray-tracing X-ray diffraction simulations are performed for an example using photoactive yellow protein crystals in order to explore the geometrical design parameters which would be needed. The specifications for an X-ray split and delay instrument that implements both an offset angle and focused beams are discussed, for implementation of a probe-pump-probe scheme at the European XFEL. We discuss possible extension of single crystal studies to serial femtosecond crystallography, particularly in view of the expected X-ray damage and ablation due to the first probe pulse.« less

  10. Beam Status

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

    Beam Status Beam Status Print Loading... You can also view the Operations Group's Beam History archives.

  11. GPU accelerated fully space and time resolved numerical simulations of self-focusing laser beams in SBS-active media

    SciTech Connect (OSTI)

    Mauger, Sarah; Colin de Verdière, Guillaume; Bergé, Luc; Skupin, Stefan; Friedrich Schiller University, Institute of Condensed Matter Theory and Optics, 07743 Jena

    2013-02-15

    A computer cluster equipped with Graphics Processing Units (GPUs) is used for simulating nonlinear optical wave packets undergoing Kerr self-focusing and stimulated Brillouin scattering in fused silica. We first recall the model equations in full (3+1) dimensions. These consist of two coupled nonlinear Schrödinger equations for counterpropagating optical beams closed with a source equation for light-induced acoustic waves seeded by thermal noise. Compared with simulations on a conventional cluster of Central Processing Units (CPUs), GPU-based computations allow us to use a significant (16 times) larger number of mesh points within similar computation times. Reciprocally, simulations employing the same number of mesh points are between 3 and 20 times faster on GPUs than on the same number of classical CPUs. Performance speedups close to 45 are reported for isolated functions evaluating, e.g., the optical nonlinearities. Since the field intensities may reach the ionization threshold of silica, the action of a defocusing electron plasma is also addressed.

  12. TH-C-17A-07: Visualizing and Quantifying Radiation Therapy in Real-Time Using a Novel Beam Imaging Technique

    SciTech Connect (OSTI)

    Jenkins, C; Naczynski, D; Xing, L

    2014-06-15

    Purpose: Radiation therapy uses invisible high energy X-rays to treat an invisible tumor. Proper positioning of the treatment beam relative to the patient's anatomy during dose delivery is critically important to the success of treatment. We develop and characterize a novel radiation therapy beam visualization technique for real-time monitoring of patient treatment. Methods: Custom made flexible scintillator sheets were fabricated from gadolinium oxysulfide (GOS) particles that had been doped with terbium within a silicone elastomer matrix. Sheets of several thicknesses ranging from 0.3 to 1mm were prepared and tested. Sheets were exposed to megavoltage X-ray and electron beams from a Varian linac and the resulting optical signal was collected by multiple CMOS cameras placed in the treatment room. Real-time images were collected for different beam energies and dose rates. Signal intensity and SNR were calculated by processing the acquired images. Results: All signals were detectable in the presence of full room lighting and at an integration time of 45ms. Average signal intensity and SNR increased with both sheet thickness and dose rate and decreased with beam energy and incident light. For a given sheet thickness and beam energy the correlation between dose rate and signal intensity was highly linear. Increased sheet thickness or dose rate results in a linear increase in the detected signal. All results are consistent with analytical approximations. Conclusion: The technique offers a means of accurately visualizing a radiation therapy beam shape and fluence in real time. The effects of salient parameters have been characterized and will enable further optimization of the technique as it is implemented into the clinical workflow. The project described was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health through UL1 TR001085.

  13. SU-D-BRE-02: Development and Commissioning of A Gated Spot Scanning Proton Beam Therapy System with Real-Time Tumor-Tracking

    SciTech Connect (OSTI)

    Umegaki, K; Matsuura, T.; Takao, S.; Nihongi, H.; Yamada, T.; Miyamoto, N.; Shimizu, S.; Shirato, H.; Matsuda, K.; Nakamura, F.; Umezawa, M.; Hiramoto, K.

    2014-06-01

    Purpose: A novel Proton Beam Therapy system has been developed by integrating Real-Time Tumor-Tracking (RTRT) and discrete spot scanning techniques. The system dedicated for spot scanning delivers significant advantages for both clinical and economical points of view. The system has the ability to control dose distribution with spot scanning beams and to gate the beams from the synchrotron to irradiate moving tumors only when the actual positions of them are within the planned position. Methods: The newly designed system consists of a synchrotron, beam transport systems, a compact and rotating gantry system with robotic couch and two orthogonal sets of X-ray fluoroscopes. The fully compact design of the system has been realized by reducing the maximum energy of the beam to 220MeV, corresponding to 30g/cm2 range and the number of circulating protons per synchrotron operation cycle, due to higher beam utilization efficiency in spot scanning. To improve the irradiation efficiency in the integration of RTRT and spot scanning, a new control system has been developed to enable multiple gated irradiation per operation cycle according to the gating signals. After the completion of the equipment installation, beam tests and commissioning has been successfully performed. Results: The basic performances and beam characteristics through the synchrotron accelerator to iso-center have been confirmed and the performance test of the irradiation nozzle and whole system has been appropriately completed. CBCT image has been checked and sufficient quality was obtained. RTRT system has been demonstrated and realized accurate dose distributions for moving targets. Conclusion: The gated spot scanning Proton Beam Therapy system with Real-Time Tumor-Tracking has been developed, successfully installed and tested. The new system enables us to deliver higher dose to the moving target tumors while sparing surrounding normal tissues and to realize the compact design of the system and facility by maximizing the efficiency of proton beam utilization. This research is granted by the Japan Society for the Promotion of Science(JSPS) through the Funding Program for World-Leading Innovative R and D on Science and Technology(FIRST Program), initiated by the Council for Science and Technology Policy(CSTP)

  14. Beam Status

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

    Beam Status Print Loading... You can also view the Operations Group's Beam History archives

  15. Magnetically operated beam dump for dumping high power beams in a neutral beamline

    DOE Patents [OSTI]

    Dagenhart, W.K.

    1984-01-27

    It is an object of this invention to provide a beam dump system for a neutral beam generator which lowers the time-averaged power density of the beam dump impingement surface. Another object of this invention is to provide a beam dump system for a neutral particle beam based on reionization and subsequent magnetic beam position modulation of the beam onto a beam dump surface to lower the time-averaged power density of the beam dump ion impingement surface.

  16. Beam-beam simulations for separated beams

    SciTech Connect (OSTI)

    Furman, Miguel A.

    2000-04-10

    We present beam-beam simulation results from a strong-strong gaussian code for separated beams for the LHC and RHIC. The frequency spectrum produced by the beam-beam collisions is readily obtained and offers a good opportunity for experimental comparisons. Although our results for the emittance blowup are preliminary, we conclude that, for nominal parameter values, there is no significant difference between separated beams and center-on-center collisions.

  17. Time-fractional Gardner equation for ion-acoustic waves in negative-ion-beam plasma with negative ions and nonthermal nonextensive electrons

    SciTech Connect (OSTI)

    Guo, Shimin Mei, Liquan; Zhang, Zhengqiang

    2015-05-15

    Nonlinear propagation of ion-acoustic waves is investigated in a one-dimensional, unmagnetized plasma consisting of positive ions, negative ions, and nonthermal electrons featuring Tsallis distribution that is penetrated by a negative-ion-beam. The classical Gardner equation is derived to describe nonlinear behavior of ion-acoustic waves in the considered plasma system via reductive perturbation technique. We convert the classical Gardner equation into the time-fractional Gardner equation by Agrawal's method, where the time-fractional term is under the sense of Riesz fractional derivative. Employing variational iteration method, we construct solitary wave solutions of the time-fractional Gardner equation with initial condition which depends on the nonlinear and dispersion coefficients. The effect of the plasma parameters on the compressive and rarefactive ion-acoustic solitary waves is also discussed in detail.

  18. Co: clqrt. Beam

    Office of Legacy Management (LM)

    Co: clqrt. Beam*/:

  19. Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider

    SciTech Connect (OSTI)

    Bruce, R.; Blaskiewicz, M.; Jowett, J.M.; Fischer, W.

    2010-09-07

    We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon {sup 197}Au{sup 79}+ beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future {sup 208}Pb+{sup 82+} beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

  20. Growth, steady-state, and time-resolved photoluminescence study of CdTe/MgCdTe double heterostructures on InSb substrates using molecular beam epitaxy

    SciTech Connect (OSTI)

    DiNezza, Michael J.; Liu, Shi; Kirk, Alexander P.; Zhang, Yong-Hang; School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287 ; Zhao, Xin-Hao; School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287

    2013-11-04

    CdTe/MgCdTe double heterostructures (DHs) are grown on InSb substrates using molecular beam epitaxy and reveal strong photoluminescence with over double the intensity of a GaAs/AlGaAs DH with an identical layer structure design grown on GaAs. Time-resolved photoluminescence of the CdTe/MgCdTe DH gives a Shockley-Read-Hall recombination lifetime of 86 ns, which is more than one order of magnitude longer than that of typical polycrystalline CdTe films. These findings indicate that monocrystalline CdTe/MgCdTe DHs effectively reduce surface recombination, have limited nonradiative interface recombination, and are promising for solar cells that could reach power conversion efficiencies similar to that of GaAs.

  1. Gated beam imager for heavy ion beams

    SciTech Connect (OSTI)

    Ahle, Larry; Hopkins, Harvey S.

    1998-12-10

    As part of the work building a small heavy-ion induction accelerator ring, or recirculator, at Lawrence Livermore National Laboratory, a diagnostic device measuring the four-dimensional transverse phase space of the beam in just a single pulse has been developed. This device, the Gated Beam Imager (GBI), consists of a thin plate filled with an array of 100-micron diameter holes and uses a Micro Channel Plate (MCP), a phosphor screen, and a CCD camera to image the beam particles that pass through the holes after they have drifted for a short distance. By time gating the MCP, the time evolution of the beam can also be measured, with each time step requiring a new pulse.

  2. Gated beam imager for heavy ion beams

    SciTech Connect (OSTI)

    Ahle, L.; Hopkins, H.S.

    1998-12-01

    As part of the work building a small heavy-ion induction accelerator ring, or recirculator, at Lawrence Livermore National Laboratory, a diagnostic device measuring the four-dimensional transverse phase space of the beam in just a single pulse has been developed. This device, the Gated Beam Imager (GBI), consists of a thin plate filled with an array of 100-micron diameter holes and uses a Micro Channel Plate (MCP), a phosphor screen, and a CCD camera to image the beam particles that pass through the holes after they have drifted for a short distance. By time gating the MCP, the time evolution of the beam can also be measured, with each time step requiring a new pulse. {copyright} {ital 1998 American Institute of Physics.}

  3. Time-dependent, x-ray spectral unfolds and brightness temperatures for intense Li{sup +} ion beam-driven hohlraums

    SciTech Connect (OSTI)

    Fehl, D.L.; Chandler, G.A.; Biggs, F.; Dukart, R.J.; Moats, A.R.; Leeper, R.J.

    1997-01-01

    X-ray-producing hohlraums are being studied as indirect drives for inertial confinement fusion targets. In a 1994 target series on the PBFAII accelerator, cylindrical hohlraum targets were heated by an intense Li{sup +} ion beam and viewed by an array of 13 time-resolved, filtered x-ray detectors (XRDs). The unfold operator (UFO) code and its suite of auxiliary functions were used extensively in obtaining time-resolved x-ray spectra and radiation temperatures from this diagnostic. The UFO was also used to obtain fitted response functions from calibration data, to simulate data from blackbody x-ray spectra of interest, to determine the suitability of various unfolding parameters (e.g., energy domain, energy partition, smoothing conditions, and basis functions), to interpolate the XRD signal traces, and to unfold experimental data. The simulation capabilities of the code were useful in understanding an anomalous feature in the unfolded spectra at low photon energies ({le}100 eV). Uncertainties in the differential and energy-integrated unfolded spectra were estimated from uncertainties in the data. The time{endash}history of the radiation temperature agreed well with independent calculations of the wall temperature in the hohlraum. {copyright} {ital 1997 American Institute of Physics.}

  4. Time-dependent, x-ray spectral unfolds and brightness temperatures for intense Li{sup +} ion beam-driven hohlraums

    SciTech Connect (OSTI)

    Fehl, D.L.; Chandler, G.A.; Biggs, F.; Dukart, R.J.; Moats, A.R.; Leeper, R.J.

    1996-07-01

    X-ray-producing hohlraums are being studied as indirect drives for Inertial Confinement Fusion targets. In a 1994 target series on the PBFAII accelerator, cylindrical hohlraum targets were heated by an intense Li{sup +} ion beam and viewed by an array of 13 time-resolved, filtered x-ray detectors (XRDs). The UFO unfold code and its suite of auxiliary functions were used extensively in obtaining time- resolved x-ray spectra and radiation temperatures from this diagnostic. UFO was also used to obtain fitted response functions from calibration data, to simulate data from blackbody x-ray spectra of interest, to determine the suitability of various unfolding parameters (e.g., energy domain, energy partition, smoothing conditions, and basis functions), to interpolate the XRD signal traces, and to unfold experimental data. The simulation capabilities of the code were useful in understanding an anomalous feature in the unfolded spectra at low photon energies ({le} 100 eV). Uncertainties in the differential and energy-integrated unfolded spectra were estimated from uncertainties in the data. The time-history of the radiation temperature agreed well with independent calculations of the wall temperature in the hohlraum.

  5. Beam Time Changes.xls

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

    He 45 55 55 55 55 55 55 55 70 70 70 14 N 40 40 40 40 40 40 40 40 50 50 50 20 Ne 50 40 25* 35 30 30 30 30 45 45 45 40 Ar 50 40 25* 35 30 30 30 30 45 45 45 63 Cu 50 40 35 35 35 35 35 35 45 45 45 84 Kr 50 40 30 30 35 25* 25 30 45 45 45 109 Ag 50 40 30 30* 35 15 15 30 45 45 45 129 Xe 50 40 30 30 35 25 25* 30 45 45 45 141 Pr 50 40 25 20* 35 25 25 25 45 45 45 165 Ho 60 50 45 45 45 45 45 45 45 30 30 181 Ta 60 50 45 45 45 45 45 45 45 30 20 197 Au 60 55 50 50 50 50 50 50 50 30 20 He N Ne Ar Cu Kr Ag Xe

  6. High resolution low dose transmission electron microscopy real-time imaging and manipulation of nano-scale objects in the electron beam

    DOE Patents [OSTI]

    Brown, Jr., R. Malcolm (Austin, TX); Barnes, Zack (Austin, TX); Sawatari, Chie (Shizuoka, JP); Kondo, Tetsuo (Kukuoka, JP)

    2008-02-26

    The present invention includes a method, apparatus and system for nanofabrication in which one or more target molecules are identified for manipulation with an electron beam and the one or more target molecules are manipulated with the electron beam to produce new useful materials.

  7. Beam imaging diagnostics for heavy ion beam fusion experiments

    SciTech Connect (OSTI)

    Bieniosek, F.M.; Prost, L.; Ghiorso, W.

    2003-05-01

    We are developing techniques for imaging beams in heavy-ion beam fusion experiments in the HIF-VNL in 2 to 4 transverse dimensions. The beams in current experiments range in energy from 50 keV to 2 MeV, with beam current densities from <10 to 200 mA/cm{sup 2}, and pulse lengths of 4 to 20 {micro}s. The beam energy will range up to 10 MeV in near-future beam experiments. The imaging techniques, based on kapton films and optical scintillators, complement and, in some cases, may replace mechanical slit scanners. The kapton film images represent a time-integrated image on the film exposed to the beam. The optical scintillator utilizes glass and ceramic scintillator material imaged by a fast, image-intensified CCD-based camera. We will discuss the techniques, results, and plans for implementation of the diagnostics on the beam experiments.

  8. Beam History

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

    Beam Status Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and day, then click on "Submit Request". Histographs are available as far back as February 2, 1994. Year 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Day 01 02 03 04 05 06 07 08 09 10 11 12 13

  9. BEAM PROPAGATOR

    Energy Science and Technology Software Center (OSTI)

    003691MLTPL00 Beam Propagator for Weather Radars, Modules 1 and 2 http://www.exelisvis.com/ProductsServices/IDL.aspx

  10. Time of Flight

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

    beam is pulsed, the energy of the neutrons that are produced can be determined by Time-of-Flight (TOF) techniques. Neutron Time-of-Flight Since the LANSCE proton beam is...

  11. Beam History

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

    Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and day, then click on "Submit Request". Histographs are available as far back as February 2, 1994. Year 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Day 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17

  12. Beam History

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

    Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and day, then click on "Submit Request". Histographs are available as far back as February 2, 1994. Year 2016 2015 2014 2013 2012 2011 2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 1998 1997 1996 1995 1994 Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Day 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17

  13. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    SciTech Connect (OSTI)

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  14. Autogenerator of beams of charged particles

    DOE Patents [OSTI]

    Adler, Richard J. (Albuquerque, NM); Mazarakis, Michael G. (Albuquerque, NM); Miller, Robert B. (Albuquerque, NM); Shope, Steven L. (Albuquerque, NM); Smith, David L. (Albuquerque, NM)

    1986-01-01

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  15. Autogenerator of beams of charged particles

    DOE Patents [OSTI]

    Adler, R.J.; Mazarakis, M.G.; Miller, R.M.; Shope, S.L.; Smith, D.L.

    1983-10-31

    An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

  16. CEBAF beam loss accounting

    SciTech Connect (OSTI)

    Ursic, R.; Mahoney, K.; Hovater, C.; Hutton, A.; Sinclair, C.

    1995-12-31

    This paper describes the design and implementation of a beam loss accounting system for the CEBAF electron accelerator. This system samples the beam curent throughout the beam path and measures the beam current accurately. Personnel Safety and Machine Protection systems use this system to turn off the beam when hazardous beam losses occur.

  17. Beam geometry selection using sequential beam addition

    SciTech Connect (OSTI)

    Popple, Richard A. Brezovich, Ivan A.; Fiveash, John B.

    2014-05-15

    Purpose: The selection of optimal beam geometry has been of interest since the inception of conformal radiotherapy. The authors report on sequential beam addition, a simple beam geometry selection method, for intensity modulated radiation therapy. Methods: The sequential beam addition algorithm (SBA) requires definition of an objective function (score) and a set of candidate beam geometries (pool). In the first iteration, the optimal score is determined for each beam in the pool and the beam with the best score selected. In the next iteration, the optimal score is calculated for each beam remaining in the pool combined with the beam selected in the first iteration, and the best scoring beam is selected. The process is repeated until the desired number of beams is reached. The authors selected three treatment sites, breast, lung, and brain, and determined beam arrangements for up to 11 beams from a pool comprised of 25 equiangular transverse beams. For the brain, arrangements were additionally selected from a pool of 22 noncoplanar beams. Scores were determined for geometries comprised equiangular transverse beams (EQA), as well as two tangential beams for the breast case. Results: In all cases, SBA resulted in scores superior to EQA. The breast case had the strongest dependence on beam geometry, for which only the 7-beam EQA geometry had a score better than the two tangential beams, whereas all SBA geometries with more than two beams were superior. In the lung case, EQA and SBA scores monotonically improved with increasing number of beams; however, SBA required fewer beams to achieve scores equivalent to EQA. For the brain case, SBA with a coplanar pool was equivalent to EQA, while the noncoplanar pool resulted in slightly better scores; however, the dose-volume histograms demonstrated that the differences were not clinically significant. Conclusions: For situations in which beam geometry has a significant effect on the objective function, SBA can identify arrangements equivalent to equiangular geometries but using fewer beams. Furthermore, SBA provides the value of the objective function as the number of beams is increased, allowing the planner to select the minimal beam number that achieves the clinical goals. The method is simple to implement and could readily be incorporated into an existing optimization system.

  18. CEBAF Beam Goes Over the Hump Highest-Energy Beam Ever Delivered at

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

    Jefferson Lab | Jefferson Lab Beam Goes Over the Hump Highest-Energy Beam Ever Delivered at Jefferson Lab Late in the evening on May 7, Jefferson Lab staff successfully threaded the electron beam up the new beamline toward Hall D for the first time Late in the evening on May 7, Jefferson Lab staff successfully threaded the electron beam up the new beamline toward Hall D for the first time. NEWPORT NEWS, VA, May 14, 2014 - The Continuous Electron Beam Accelerator Facility (CEBAF) at the U.S.

  19. Laser beam monitoring system

    DOE Patents [OSTI]

    Weil, Bradley S. (Knoxville, TN); Wetherington, Jr., Grady R. (Harriman, TN)

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  20. Beam imaging sensor

    DOE Patents [OSTI]

    McAninch, Michael D; Root, Jeffrey J

    2015-03-31

    The present invention relates generally to the field of sensors for beam imaging and, in particular, to a new and useful beam imaging sensor for use in determining, for example, the power density distribution of a beam including, but not limited to, an electron beam or an ion beam. In one embodiment, the beam imaging sensor of the present invention comprises, among other items, a circumferential slit that is either circular, elliptical or polygonal in nature.

  1. BEAM INSTRUMENTATION FOR HIGH POWER HADRON BEAMS

    SciTech Connect (OSTI)

    Aleksandrov, Alexander V

    2013-01-01

    This presentation will describe developments in the beam diagnostics which support the understanding and operation of high power hadron accelerators. These include the measurement of large dynamic range transverse and longitudinal beam profiles, beam loss detection, and non-interceptive diagnostics.

  2. Summary of the LARP Mini-Workshop on Beam-Beam Compensation 2007

    SciTech Connect (OSTI)

    Fischer, Wolfram; Bruning, Oliver S.; Koutchouk, J.P.; Zimmermann, F.; Sen, T.; Shiltsev, V.; Ohmi, K.; Furman, M.; Cai, Y.; Chao, A.; /SLAC

    2011-11-07

    The LARP Mini-Workshop on Beam-Beam Compensation 2007 was held at SLAC, 2-4 July 2007. It was attended by 33 participants from 10 institutions in Asia, Europe, and America. 26 presentations were given, while more than one third of the time was allocated to discussions. The workshop web site is Ref. [1]. The workshop's main focus was on long-range and head-on beam-beam compensation, with a view towards application in the LHC. Other topics included the beam-beam performance of previous, existing and future circular colliders; beam-beam simulations; new operating modes, theory, and unexplained phenomena. This summary is also published as Ref. [2].

  3. BEAM CONTAINMENT SYSTEM FOR NSLS-II

    SciTech Connect (OSTI)

    Kramer, S.L.; Casey, W.; Job, P.K.

    2010-05-23

    The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (and potentially to measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R&D program will be presented.

  4. 6.21 Improving Neutron Beams for Cancer Treatment

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

    1 612011 6.21 Improving Neutron Beams for Cancer Treatment Beams of neutrons long have been used in scientific experiments, but recently, for the first time, a novel type of...

  5. Electron beam diagnostic for profiling high power beams

    DOE Patents [OSTI]

    Elmer, John W. (Danville, CA); Palmer, Todd A. (Livermore, CA); Teruya, Alan T. (Livermore, CA)

    2008-03-25

    A system for characterizing high power electron beams at power levels of 10 kW and above is described. This system is comprised of a slit disk assembly having a multitude of radial slits, a conducting disk with the same number of radial slits located below the slit disk assembly, a Faraday cup assembly located below the conducting disk, and a start-stop target located proximate the slit disk assembly. In order to keep the system from over-heating during use, a heat sink is placed in close proximity to the components discussed above, and an active cooling system, using water, for example, can be integrated into the heat sink. During use, the high power beam is initially directed onto a start-stop target and after reaching its full power is translated around the slit disk assembly, wherein the beam enters the radial slits and the conducting disk radial slits and is detected at the Faraday cup assembly. A trigger probe assembly can also be integrated into the system in order to aid in the determination of the proper orientation of the beam during reconstruction. After passing over each of the slits, the beam is then rapidly translated back to the start-stop target to minimize the amount of time that the high power beam comes in contact with the slit disk assembly. The data obtained by the system is then transferred into a computer system, where a computer tomography algorithm is used to reconstruct the power density distribution of the beam.

  6. Pyramid beam splitter

    DOE Patents [OSTI]

    McKeown, Mark H. (Golden, CO); Beason, Steven C. (Lakewood, CO); Fairer, George (Boulder, CO)

    1992-01-01

    The apparatus of the present invention provides means for obtaining accurate, dependable, measurement of bearings and directions for geologic mapping in subterranean shafts, such as, for example, nuclear waste storage investigations. In operation, a laser beam is projected along a reference bearing. A pyramid is mounted such that the laser beam is parallel to the pyramid axis and can impinge on the apex of the pyramid thus splitting the beam several ways into several beams at right angles to each other and at right angles to the reference beam. The pyramid is also translatable and rotatable in a plane perpendicular to the reference beam.

  7. Beam position monitor

    DOE Patents [OSTI]

    Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

    2003-07-22

    An apparatus for determining the position of an x-ray beam relative to a desired beam axis. Where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in an a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

  8. Shimmed electron beam welding process

    DOE Patents [OSTI]

    Feng, Ganjiang (Clifton Park, NY); Nowak, Daniel Anthony (Alplaus, NY); Murphy, John Thomas (Niskayuna, NY)

    2002-01-01

    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  9. Beam Dynamics for ARIA

    SciTech Connect (OSTI)

    Ekdahl, Carl August Jr.

    2014-10-14

    Beam dynamics issues are assessed for a new linear induction electron accelerator being designed for flash radiography of large explosively driven hydrodynamic experiments. Special attention is paid to equilibrium beam transport, possible emittance growth, and beam stability. It is concluded that a radiographic quality beam will be produced possible if engineering standards and construction details are equivalent to those on the present radiography accelerators at Los Alamos.

  10. 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.

  11. Measurements - Ion Beams - Radiation Effects Facility / Cyclotron Institute

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

    / Texas A&M University Ion Beams Available Beams / Beam Change Times / Measurements / Useful Graphs Measurements The beam uniformity and flux are determined using an array of five detectors. Each detector is made up with a plastic scintillator coupled to photo-multiplier tubes. Four of the detectors are fixed in position and set up to measure beam particle counting rates continuously at four characteristic points 1.64 inches (4.71 mm) away from the beam axis. The fifth scintillator can

  12. Injected Beam Dynamics in SPEAR3

    SciTech Connect (OSTI)

    Corbett, Jeff; Fisher, Alan; Huang, Xiaobiao; Safranek, James; Westerman, Stuart; Cheng, Weixing; Mok, Walter; /Unlisted

    2012-06-21

    For the top-off operation it is important to understand the time evolution of charge injected into the storage ring. The large-amplitude horizontal oscillation quickly filaments and decoheres, and in some cases exhibits non-linear x-y coupling before damping to the stored orbit. Similarly, in the longitudinal dimension, any mismatch in beam arrival time, beam energy or phase-space results in damped, non-linear synchrotron oscillations. In this paper we report on measurements of injection beam dynamics in the transverse and longitudinal planes using turn-by-turn BPMs, a fast-gated, image-intensified CCD camera and a Hamamatsu C5680 streak camera.

  13. Neutral beam monitoring

    DOE Patents [OSTI]

    Fink, Joel H. (Livermore, CA)

    1981-08-18

    Method and apparatus for monitoring characteristics of a high energy neutral beam. A neutral beam is generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange neutralizes the high energy ion beam. The neutral beam is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are further identified.

  14. EMITTANCE COMPENSATION FOR MAGNETIZED BEAMS

    SciTech Connect (OSTI)

    KEWISCH,J.; CHANG, X.

    2007-06-25

    Emittance compensation is a well established technique for minimizing the emittance of an electron beam from a RF photo-cathode gun. Longitudinal slices of a bunch have a small emittance, but due to the longitudinal charge distribution of the bunch and time dependent RF fields they are not focused in the same way, so that the direction of their phase ellipses diverges in phase space and the projected emittance is much larger. Emittance compensation reverses the divergence. At the location where the slopes of the phase ellipses coincide the beam is accelerated, so that the space charge forces are reduced. A recipe for emittance compensation is given in. For magnetized beams (where the angular momentum is non-zero) such emittance compensation is not sufficient because variations in the slice radius lead to variations in the angular speed and therefore to an increase of emittance in the rotating game. We describe a method and tools for a compensation that includes the beam magnetization.

  15. Status of RHIC head-on beam-beam compensation project

    SciTech Connect (OSTI)

    Fischer, W.; Anerella, M.; Beebe, E.; Bruno, D.; Gassner, D.M.; Gu, X.; Gupta, R.C.; Hock, J.; Jain, A.K.; Lambiase, R.; Liu, C.; Luo, Y.; Mapes, M.; Montag, C.; Oerter, B.; Okamura, M.; Pikin, A.I.; Raparia, D.; Tan, Y.; Than, R.; Thieberger, P.; Tuozzolo, J.; Zhang, W.

    2011-03-28

    Two electron lenses are under construction for RHIC to partially compensate the head-on beam-beam effect in order to increase both the peak and average luminosities. The final design of the overall system is reported as well as the status of the component design, acquisition, and manufacturing. An overview of the RHIC head-on beam-beam compensation project is given in [1], and more details in [2]. With 2 head-on beam-beam interactions in IP6 and IP8, a third interaction with a low-energy electron beam is added near IP10 to partially compensate the the head-on beam-beam effect. Two electron lenses are under construction, one for each ring. Both will be located in a region common to both beams, but each lens will act only on one beam. With head-on beam-beam compensation up to a factor of two improvement in luminosity is expected together with a polarized source upgrade. The current RHIC polarized proton performance is documented in Ref. [4]. An electron lens (Fig. 1) consists of an DC electron gun, warm solenoids to focus the electron beam during transport, a superconducting main solenoid in which the interaction with the proton beam occurs, steering magnets, a collector, and instrumentation. The main developments in the last year are given below. The experimental program for polarized program at 100 GeV was expected to be finished by the time the electron lenses are commissioned. However, decadal plans by the RHIC experiments STAR and PHENIX show a continuing interest at both 100 GeV and 250 GeV, and a larger proton beam size has been accommodated in the design (Tab. 1). Over the last year beam and lattice parameters were optimized, and RHIC proton lattices are under development for optimized electron lens performance. The effect of the electron lens magnetic structure on the proton beam was evaluated, and found to be correctable. Experiments were done in RHIC and the Tevatron.

  16. Beam Instrumentation Workshop

    SciTech Connect (OSTI)

    Shafer, R.E. )

    1994-01-01

    The fifth annual Beam Instrumentation Workshop was hosted by Los Alamos National Laboratory in Santa Fe, New Mexico. These proceedings represent the papers presented at the Workshop. A variety of topics were covered including beam emittance diagnostics, fluorescent screens, control systems for many accelerators and photon sources. Beam monitoring was discussed in great detail. There were thirty seven papers presented at the Workshop and all have been abstracted for the Energy and Science Technology database. (AIP)

  17. Broad beam ion implanter

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA)

    1996-01-01

    An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

  18. Neutral beam dump with cathodic arc titanium gettering

    SciTech Connect (OSTI)

    Smirnov, A.; Korepanov, S. A.; Putvinski, S.; Krivenko, A. S.; Murakhtin, S. V.; Savkin, V. Ya.

    2011-03-15

    An incomplete neutral beam capture can degrade the plasma performance in neutral beam driven plasma machines. The beam dumps mitigating the shine-through beam recycling must entrap and retain large particle loads while maintaining the beam-exposed surfaces clean of the residual impurities. The cathodic arc gettering, which provides high evaporation rate coupled with a fast time response, is a powerful and versatile technique for depositing clean getter films in vacuum. A compact neutral beam dump utilizing the titanium arc gettering was developed for a field-reversed configuration plasma sustained by 1 MW, 20-40 keV neutral hydrogen beams. The titanium evaporator features a new improved design. The beam dump is capable of handling large pulsed gas loads, has a high sorption capacity, and is robust and reliable. With the beam particle flux density of 5 x 10{sup 17} H/(cm{sup 2}s) sustained for 3-10 ms, the beam recycling coefficient, defined as twice the ratio of the hydrogen molecular flux leaving the beam dump to the incident flux of high-energy neutral atoms, is {approx}0.7. The use of the beam dump allows us to significantly reduce the recycling of the shine-through neutral beam as well as to improve the vacuum conditions in the machine.

  19. Control and manipulation of electron beams

    SciTech Connect (OSTI)

    Piot, Philippe; /NICADD, DeKalb /Northern Illinois U. /Fermilab

    2008-09-01

    The concepts of the advanced accelerators and light source rely on the production of bright electron beams. The rms areas of the beam phase space often need to be tailored to the specific applications. Furthermore, a new class of the forefront research calls for detailed specific distribution such as the particle density in the time coordinate. Several groups are tackling these various challenges and in this report we attempt to give a review of the state-of-the-art of the control and manipulation of the electron beams.

  20. SNS BEAM COMMISSIONING TOOLS AND EXPERIENCE

    SciTech Connect (OSTI)

    Shishlo, Andrei P; Galambos, John D

    2008-01-01

    The Spallation Neutron Source (SNS) successfully met the primary construction project completion milestones in April 2006. An important ingredient of this successful commissioning was the development and use of software tools. With the increasing digitalization of beam diagnostics and increasing complexity of Integrated Control Systems of large accelerators, the need for high level software tools is critical for smooth commissioning. At SNS a special Java based infrastructure called XAL was prepared for beam commissioning. XAL provides a hierarchal view of the accelerator, is data base configured, and includes a physics model of the beam. This infrastructure and individual applications development along with a historical time line of the SNS commissioning will be discussed.

  1. Apparatus for laser beam profile measurements

    DOE Patents [OSTI]

    Barnes, N.P.; Gettemy, D.J.

    1985-01-30

    Apparatus for measuring the spatial intensity profile of the output beam from a continuous-wave laser oscillator. The rapid and repetitive passing of a small aperture through the otherwise totally blocked output beam of the laser under investigation provides an easily interpretable, real-time measure of the intensity characteristics thereof when detected by a single detector and the signal generated thereby displayed on an oscilloscope synthronized to the motion of the aperture.

  2. High speed x-ray beam chopper

    DOE Patents [OSTI]

    McPherson, Armon (Oswego, IL); Mills, Dennis M. (Naperville, IL)

    2002-01-01

    A fast, economical, and compact x-ray beam chopper with a small mass and a small moment of inertia whose rotation can be synchronized and phase locked to an electronic signal from an x-ray source and be monitored by a light beam is disclosed. X-ray bursts shorter than 2.5 microseconds have been produced with a jitter time of less than 3 ns.

  3. High sensitivity charge amplifier for ion beam uniformity monitor

    DOE Patents [OSTI]

    Johnson, Gary W. (Livermore, CA)

    2001-01-01

    An ion beam uniformity monitor for very low beam currents using a high-sensitivity charge amplifier with bias compensation. The ion beam monitor is used to assess the uniformity of a raster-scanned ion beam, such as used in an ion implanter, and utilizes four Faraday cups placed in the geometric corners of the target area. Current from each cup is integrated with respect to time, thus measuring accumulated dose, or charge, in Coulombs. By comparing the dose at each corner, a qualitative assessment of ion beam uniformity is made possible. With knowledge of the relative area of the Faraday cups, the ion flux and areal dose can also be obtained.

  4. Fifteen Years of Beam on Target | Jefferson Lab

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

    Fifteen Years of Beam on Target First beam enters Hall C First beam enters Hall C. On July 1, 1994, Jefferson Lab's accelerator delivered an electron beam into one of its experimental halls for the first time. It was just 10 years after the lab's founding and the construction of its first-of-a-kind accelerator. Great Expectations Initial plans called for a machine that could "accelerate" a more-or-less continuous beam of electrons by stuffing each electron with up to four billion

  5. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, B.E.; Duncan, D.B.

    1993-12-28

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 11 figures.

  6. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, B.E.; Duncan, D.B.

    1994-02-15

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus is described. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 7 figures.

  7. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

    1994-01-01

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

  8. Laser beam generating apparatus

    DOE Patents [OSTI]

    Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

    1993-01-01

    Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

  9. Beam intensity upgrade at Fermilab

    SciTech Connect (OSTI)

    Marchionni, A.; /Fermilab

    2006-07-01

    The performance of the Fermilab proton accelerator complex is reviewed. The coming into operation of the NuMI neutrino line and the implementation of slip-stacking to increase the anti-proton production rate has pushed the total beam intensity in the Main Injector up to {approx} 3 x 10{sup 13} protons/pulse. A maximum beam power of 270 kW has been delivered on the NuMI target during the first year of operation. A plan is in place to increase it to 350 kW, in parallel with the operation of the Collider program. As more machines of the Fermilab complex become available with the termination of the Collider operation, a set of upgrades are being planned to reach first 700 kW and then 1.2 MW by reducing the Main Injector cycle time and by implementing proton stacking.

  10. Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Journal Article: Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams Citation Details In-Document Search Title: Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design

  11. Electron Lens for Beam-Beam Compensation at LHC

    SciTech Connect (OSTI)

    Valishev, A.; Shiltsev, V.; /Fermilab

    2009-05-01

    Head-on beam-beam effect may become a major performance limitation for the LHC in some of the upgrade scenarios. Given the vast experience gained from the operation of Tevatron electron lenses, a similar device provides significant potential for mitigation of beam-beam effects at the LHC. In this report we present the results of simulation studies of beam-beam compensation and analyze potential application of electron lense at LHC and RHIC.

  12. STUDY OF ELECTRON -PROTON BEAM-BEAM INTERACTION IN ERHIC

    SciTech Connect (OSTI)

    HAO,Y.; LITVINENKO, V.N.; MONTAG, C.; POZDEYEV, E.; PTITSYN, V.

    2007-06-25

    Beam-beam effects present one of major factors limiting the luminosity of colliders. In the linac-ring option of eRHIC design, an electron beam accelerated in a superconducting energy recovery linac collides with a proton beam circulating in the RHIC ring. There are some features of beam-beam effects, which require careful examination in linac-ring configuration. First, the beam-beam interaction can induce specific head-tail type instability of the proton beam referred to as a ''kink'' instability. Thus, beam stability conditions should be established to avoid proton beam loss. Also, the electron beam transverse disruption by collisions has to be evaluated to ensure beam quality is good enough for the energy recovery pass. In addition, fluctuations of electron beam current and/or electron beam size, as well as transverse offset, can cause proton beam emittance growth. The tolerances for those factors should be determined and possible countermeasures should be developed to mitigate the emittance growth. In this paper, a soft Gaussian strong-strong simulation is used to study all of mentioned beam-beam interaction features and possible techniques to reduce the emittance growth.

  13. Laser diagnostic for high current H{sup {minus}} beams

    SciTech Connect (OSTI)

    Shafer, R.E.

    1998-12-01

    In the last 5 years, significant technology advances have been made in the performance, size, and cost of solid-state diode-pumped lasers. These developments enable the use of compact Q-switched Nd:YAG lasers as a beam diagnostic for high current H{sup {minus}} beams. Because the threshold for photodetachment is only 0.75 eV, and the maximum detachment cross section is 4{times}10{sup {minus}17}cm{sup 2} at 1.5 eV, A 50 mJ/pulse Q-switched Nd:YAG laser can neutralize a significant fraction of the beam in a single 10 ns wide pulse. The neutral beam maintains nearly identical parameters as the parent H{sup {minus}} beam, including size, divergence, energy, energy spread, and phase spread. A dipole magnet can separate the neutral beam from the H{sup {minus}} beam to allow diagnostics on the neutral beam without intercepting the high-current H{sup {minus}} beam. Such a laser system can also be used to extract a low current proton beam, or to induce fluorescence in partially stripped heavy ion beams. Possible beamline diagnostic systems will be reviewed, and the neutral beam yields will be calculated. {copyright} {ital 1998 American Institute of Physics.}

  14. Laser diagnostic for high current H{sup {minus}} beams

    SciTech Connect (OSTI)

    Shafer, R.E.

    1998-05-05

    In the last 5 years, significant technology advances have been made in the performance, size, and cost of solid-state diode-pumped lasers. These developments enable the use of compact Q-switched Nd:YAG lasers as a beam diagnostic for high current H{sup {minus}} beams. Because the threshold for photodetachment is only 0.75 eV, and the maximum detachment cross section is 4 {times} 10{sup {minus}17} cm{sup 2} at 1.5 eV, a 50 mJ/pulse Q-switched Nd:YAG laser can neutralize a significant fraction of the beam in a single 10-ns wide pulse. The neutral beam maintains nearly identical parameters as the parent H{sup {minus}} beam, including size, divergence, energy, energy spread, and phase spread. A dipole magnet can separate the neutral beam from the H{sup {minus}} beam to allow diagnostics on the neutral beam without intercepting the high-current H{sup {minus}} beam. Such a laser system can also be used to extract a low current proton beam, or to induce fluorescence in partially stripped heavy ion beams. Possible beamline diagnostic systems will be reviewed, and the neutral beam yields will be calculated.

  15. BEAMS: Curiosity | Jefferson Lab

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

    BEAMS: Curiosity January 9, 2013 BEAMS, Becoming Excited About Math and Science, is one of our education programs. In particular, it is the only one in which I participate with more than a ceremonial role. I try my best to pull my full share of BEAMS visits. Today was the first of the year, and it went really well. There were about a dozen middle school kids in my office, plus the teacher. Of course, the lab's education team ensures complete immersion by making themselves scarce for the allotted

  16. Ion beam lithography system

    DOE Patents [OSTI]

    Leung, Ka-Ngo

    2005-08-02

    A maskless plasma-formed ion beam lithography tool provides for patterning of sub-50 nm features on large area flat or curved substrate surfaces. The system is very compact and does not require an accelerator column and electrostatic beam scanning components. The patterns are formed by switching beamlets on or off from a two electrode blanking system with the substrate being scanned mechanically in one dimension. This arrangement can provide a maskless nano-beam lithography tool for economic and high throughput processing.

  17. Systems and methods of varying charged particle beam spot size

    DOE Patents [OSTI]

    Chen, Yu-Jiuan

    2014-09-02

    Methods and devices enable shaping of a charged particle beam. A modified dielectric wall accelerator includes a high gradient lens section and a main section. The high gradient lens section can be dynamically adjusted to establish the desired electric fields to minimize undesirable transverse defocusing fields at the entrance to the dielectric wall accelerator. Once a baseline setting with desirable output beam characteristic is established, the output beam can be dynamically modified to vary the output beam characteristics. The output beam can be modified by slightly adjusting the electric fields established across different sections of the modified dielectric wall accelerator. Additional control over the shape of the output beam can be excreted by introducing intentional timing de-synchronization offsets and producing an injected beam that is not fully matched to the entrance of the modified dielectric accelerator.

  18. LEDA BEAM DIAGNOSTICS INSTRUMENTATION: BEAM POSITION MONITORS

    SciTech Connect (OSTI)

    D. BARR; ET AL

    2000-05-01

    The Low Energy Demonstration Accelerator (LEDA) facility located at Los Alamos National Laboratory (LANL) accelerates protons to an energy of 6.7-MeV and current of 100-mA operating in either a pulsed or cw mode. Of key importance to the commissioning and operations effort is the Beam Position Monitor system (BPM). The LEDA BPM system uses five micro-stripline beam position monitors processed by log ratio processing electronics with data acquisition via a series of custom TMS32OC40 Digital Signal Processing (DSP) boards. Of special interest to this paper is the operation of the system, the log ratio processing, and the system calibration technique. This paper will also cover the DSP system operations and their interaction with the main accelerator control system.

  19. Neutral particle beam intensity controller

    DOE Patents [OSTI]

    Dagenhart, W.K.

    1984-05-29

    The neutral beam intensity controller is based on selected magnetic defocusing of the ion beam prior to neutralization. The defocused portion of the beam is dumped onto a beam dump disposed perpendicular to the beam axis. Selective defocusing is accomplished by means of a magnetic field generator disposed about the neutralizer so that the field is transverse to the beam axis. The magnetic field intensity is varied to provide the selected partial beam defocusing of the ions prior to neutralization. The desired focused neutral beam portion passes along the beam path through a defining aperture in the beam dump, thereby controlling the desired fraction of neutral particles transmitted to a utilization device without altering the kinetic energy level of the desired neutral particle fraction. By proper selection of the magnetic field intensity, virtually zero through 100% intensity control of the neutral beam is achieved.

  20. SSRL BEAM PORT SCHEDULE

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

    Aug. 17, 2015 Back to Table of Contents WEEK OF Nov. 17, 2014 Nov. 17, 2014 Nov. 18, 2014 Nov. 19, 2014 Nov. 20, 2014 Nov. 21, 2014 Nov. 22, 2014 Nov. 23, 2014 BEAM LINE 5-4 Nov....

  1. Beam! Magic! | Jefferson Lab

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

    with all the changes, the accelerator can be made to work. Beam Since my first serious introduction to nuclear and particle physics - when I worked for a few weeks one summer at...

  2. Focused ion beam system

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Gough, Richard A. (Kensington, CA); Ji, Qing (Berkeley, CA); Lee, Yung-Hee Yvette (Berkeley, CA)

    1999-01-01

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 .mu.m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 .mu.m or less.

  3. Focused ion beam system

    DOE Patents [OSTI]

    Leung, K.; Gough, R.A.; Ji, Q.; Lee, Y.Y.

    1999-08-31

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 {mu}m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 m or less. 13 figs.

  4. Beam instrumentation for the Tevatron Collider

    SciTech Connect (OSTI)

    Moore, Ronald S.; Jansson, Andreas; Shiltsev, Vladimir; /Fermilab

    2009-10-01

    The Tevatron in Collider Run II (2001-present) is operating with six times more bunches and many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, outline machine needs for new instrumentation, present several notable examples that led to Tevatron performance improvements, and discuss the lessons for future colliders.

  5. Photon beam position monitor

    DOE Patents [OSTI]

    Kuzay, T.M.; Shu, D.

    1995-02-07

    A photon beam position monitor is disclosed for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade ''shadowing''. Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation. 18 figs.

  6. Photon beam position monitor

    DOE Patents [OSTI]

    Kuzay, Tuncer M. (Naperville, IL); Shu, Deming (Darien, IL)

    1995-01-01

    A photon beam position monitor for use in the front end of a beamline of a high heat flux and high energy photon source such as a synchrotron radiation storage ring detects and measures the position and, when a pair of such monitors are used in tandem, the slope of a photon beam emanating from an insertion device such as a wiggler or an undulator inserted in the straight sections of the ring. The photon beam position monitor includes a plurality of spaced blades for precisely locating the photon beam, with each blade comprised of chemical vapor deposition (CVD) diamond with an outer metal coating of a photon sensitive metal such as tungsten, molybdenum, etc., which combination emits electrons when a high energy photon beam is incident upon the blade. Two such monitors are contemplated for use in the front end of the beamline, with the two monitors having vertically and horizontally offset detector blades to avoid blade "shadowing". Provision is made for aligning the detector blades with the photon beam and limiting detector blade temperature during operation.

  7. Beam/seam alignment control for electron beam welding

    DOE Patents [OSTI]

    Burkhardt, Jr., James H. (Knoxville, TN); Henry, J. James (Oak Ridge, TN); Davenport, Clyde M. (Knoxville, TN)

    1980-01-01

    This invention relates to a dynamic beam/seam alignment control system for electron beam welds utilizing video apparatus. The system includes automatic control of workpiece illumination, near infrared illumination of the workpiece to limit the range of illumination and camera sensitivity adjustment, curve fitting of seam position data to obtain an accurate measure of beam/seam alignment, and automatic beam detection and calculation of the threshold beam level from the peak beam level of the preceding video line to locate the beam or seam edges.

  8. Electron beam magnetic switch for a plurality of free electron lasers

    DOE Patents [OSTI]

    Schlitt, Leland G. (Livermore, CA)

    1984-01-01

    Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

  9. Single element laser beam shaper

    DOE Patents [OSTI]

    Zhang, Shukui (Yorktown, VA); Michelle D. Shinn (Newport News, VA)

    2005-09-13

    A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

  10. Apparatus and method for laser beam diagnosis

    DOE Patents [OSTI]

    Salmon, J.T. Jr.

    1991-08-27

    An apparatus and method are disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam. 11 figures.

  11. Apparatus and method for laser beam diagnosis

    DOE Patents [OSTI]

    Salmon, Jr., Joseph T. (Livermore, CA)

    1991-01-01

    An apparatus and method is disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam.

  12. MINER{nu}A Test Beam Commissioning

    SciTech Connect (OSTI)

    Higuera, A.; Castorena, J.; Urrutia, Z.; Felix, J.; Zavala, G.

    2009-12-17

    MINER{nu}A Main INjector ExpeRiment {nu}-A is a high-statistic neutrino scattering experiment that will ran in the NuMI Beam Hall at Fermilab. To calibrate the energy response of the MINER{nu}A detector, a beamline is being designed for the MINER{nu}A Test Beam Detector (TBD). The TBD is a replica of the full MINER{nu}A detector at small scale for calibration studies of the main detector. The beamline design consists of the following parts: a copper target, used to generate tertiaries from an incoming secondary beam; a steel collimator for tertiaries, which also serves as a dump for the incoming beam; a time of fight system (scintillator planes); four wire chambers, for angle measurements and tracking; and two dipole magnets, used as an spectrometer. During last October, the first commissioning run of the MINER{nu}A Test Beam took place in the Meson Test Beam Facility at Fermilab. We commissioned the target and collimator of the new tertiary beamline.

  13. Beam Characterizations at Femtosecond Electron Beam Facility

    SciTech Connect (OSTI)

    Rimjaem, S.; Jinamoon, V.; Kangrang, M.; Kusoljariyakul, K.; Saisut, J.; Thongbai, C.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; Wiedemann, H.; /SLAC

    2006-03-17

    The SURIYA project at the Fast Neutron Research Facility (FNRF) has been established and is being commissioning to generate femtosecond (fs) electron bunches. Theses short bunches are produced by a system consisting of an S-band thermionic cathode RF-gun, an alpha magnet (a-magnet) serving as a magnetic bunch compressor, and a SLAC-type linear accelerator (linac). The characteristics of its major components and the beam characterizations as well as the preliminary experimental results will be presented and discussed in this paper.

  14. ICFA Beam Dynamics Newsletter

    SciTech Connect (OSTI)

    Ben-Zvi I.; Kuczewski A.; Altinbas, Z.; Beavis, D.; Belomestnykh,; Dai, J. et al

    2012-07-01

    The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL features a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.

  15. Beam-beam observations in the Relativistic Heavy Ion Collider

    SciTech Connect (OSTI)

    Luo, Y.; Fischer, W.; White, S.

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  16. LHC beam-beam compensation studies at RHIC

    SciTech Connect (OSTI)

    Fischer,W.; Abreu, N.; Calaga, R.; Robert-Demolaize, G.; Luo, Y.; Montag, C.

    2009-05-04

    Long-range and head-on beam-beam effects are expected to limit the LHC performance with design parameters. To mitigate long-range effects current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. To reduce the head-on beam-beam effect electron lenses were proposed for both the LHC and RHIC. We present the experimental long-range beam-beam program and report on head-on compensations studies at RHIC, which are based on simulations.

  17. Method and apparatus for measuring properties of particle beams using thermo-resistive material properties

    DOE Patents [OSTI]

    Degtiarenko, Pavel V. (Williamsburg, VA); Dotson, Danny Wayne (Gloucester, VA)

    2007-10-09

    A beam position detector for measuring the properties of a charged particle beam, including the beam's position, size, shape, and intensity. One or more absorbers are constructed of thermo-resistive material and positioned to intercept and absorb a portion of the incoming beam power, thereby causing local heating of each absorber. The local temperature increase distribution across the absorber, or the distribution between different absorbers, will depend on the intensity, size, and position of the beam. The absorbers are constructed of a material having a strong dependence of electrical resistivity on temperature. The beam position detector has no moving parts in the vicinity of the beam and is especially suited to beam areas having high ionizing radiation dose rates or poor beam quality, including beams dispersed in the transverse direction and in their time radio frequency structure.

  18. The backward phase flow and FBI-transform-based Eulerian Gaussian beams for the Schroedinger equation

    SciTech Connect (OSTI)

    Leung Shingyu; Qian Jianliang

    2010-11-20

    We propose the backward phase flow method to implement the Fourier-Bros-Iagolnitzer (FBI)-transform-based Eulerian Gaussian beam method for solving the Schroedinger equation in the semi-classical regime. The idea of Eulerian Gaussian beams has been first proposed in . In this paper we aim at two crucial computational issues of the Eulerian Gaussian beam method: how to carry out long-time beam propagation and how to compute beam ingredients rapidly in phase space. By virtue of the FBI transform, we address the first issue by introducing the reinitialization strategy into the Eulerian Gaussian beam framework. Essentially we reinitialize beam propagation by applying the FBI transform to wavefields at intermediate time steps when the beams become too wide. To address the second issue, inspired by the original phase flow method, we propose the backward phase flow method which allows us to compute beam ingredients rapidly. Numerical examples demonstrate the efficiency and accuracy of the proposed algorithms.

  19. Beam Profile Monitor With Accurate Horizontal And Vertical Beam Profiles

    DOE Patents [OSTI]

    Havener, Charles C [Knoxville, TN; Al-Rejoub, Riad [Oak Ridge, TN

    2005-12-26

    A widely used scanner device that rotates a single helically shaped wire probe in and out of a particle beam at different beamline positions to give a pair of mutually perpendicular beam profiles is modified by the addition of a second wire probe. As a result, a pair of mutually perpendicular beam profiles is obtained at a first beamline position, and a second pair of mutually perpendicular beam profiles is obtained at a second beamline position. The simple modification not only provides more accurate beam profiles, but also provides a measurement of the beam divergence and quality in a single compact device.

  20. Beam test of the SDC barrel EM calorimeter test module

    SciTech Connect (OSTI)

    Balka, L.; Guarino, V.; Hill, N.

    1994-05-01

    The SDC barrel electromagnetic calorimeter test module was exposed to beams of high energy pions and electrons in the MP9 test beam at Fermilab in the fall of 1991. Data were collected on resolution, light yield, signal timing and hermiticity. These data demonstrated that the design met the specifications for the barrel electromagnetic calorimeter of the Solenoidal Detector collaboration (SDC).

  1. Neutral-beam development plan, FY 1982-1987

    SciTech Connect (OSTI)

    Not Available

    1981-09-01

    The following chapters are included: (1) status of BNL negative ion source development, (2) source development program plan, (3) status of beam transport and acceleration, (4) accelerator development program plan, (5) neutralizer concepts, (6) neutralization program plan, (7) neutral beam systems, (8) test facilities, (9) program milestones and time schedules, (10) organization and Grumman participation, and (11) funding tables. (MOW)

  2. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOE Patents [OSTI]

    Birx, Daniel L. (Brentwood, CA); Reginato, Louis L. (Orinda, CA)

    1988-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .gtoreq.0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  3. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOE Patents [OSTI]

    Birx, D.L.; Reginato, L.L.

    1984-03-22

    An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

  4. Electron beam accelerator with magnetic pulse compression and accelerator switching

    DOE Patents [OSTI]

    Birx, Daniel L. (Brentwood, CA); Reginato, Louis L. (Orinda, CA)

    1987-01-01

    An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially 0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

  5. SSRL BEAM PORT SCHEDULE

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

    4 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 1-5 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 2-1 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19,

  6. SSRL BEAM PORT SCHEDULE

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

    Back to Table of Contents WEEK OF Nov. 17, 2014 Nov. 17, 2014 Nov. 18, 2014 Nov. 19, 2014 Nov. 20, 2014 Nov. 21, 2014 Nov. 22, 2014 Nov. 23, 2014 BEAM LINE 7-1 Nov. 17, 2014 Nov. 18, 2014 Nov. 19, 2014 Nov. 20, 2014 Nov. 21, 2014 Nov. 22, 2014 Nov. 23, 2014 Unscheduled STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP STUP BEAM LINE 11-1 Nov. 17, 2014 Nov. 18, 2014 Nov. 19, 2014 Nov. 20, 2014 Nov. 21, 2014 Nov. 22, 2014 Nov. 23, 2014 Unscheduled STUP

  7. SSRL BEAM PORT SCHEDULE

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

    1-4 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 2-1 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 2-2 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar.

  8. Beam position monitor sensitivity for low-{beta} beams

    SciTech Connect (OSTI)

    Shafer, R.E.

    1993-11-01

    At low velocities, the EM field of a particle in a conducting beam tube is no longer a TEM wave, but has a finite longitudinal extent. The net effect of this is to reduce the coupling of the high-frequency Fourier components of the beam current to BPM (beam position monitor) electrodes, which modifies the BPM sensitivity to beam displacement. This effect is especially pronounced for high-frequency, large-aperture pickups used for low-{beta} beams. Non-interceptive beam position monitors used in conjunction with high frequency RFQ (radio-frequency-quadrupole) and DTL (drift-tube-linac) accelerators fall into this category. When testing a BPM with a thin wire excited with either pulses or high-frequency sinusoidal currents, the EM wave represents the principal (TEM) mode in a coaxial transmission line, which is equivalent to a highly relativistic ({beta} = 1) beam. Thus wire measurements are not suitable for simulating slow particle beams in high bandwidth diagnostic devices that couple to the image currents in the beam tube wall. Attempts to load the tin wire either capacitively or inductively to slow the EM wave down have met with limited success. In general, the equations used to represent the 2-D response of cylindrical-geometry BPMs to charged-particle beams make several assumptions: (1) the BPM electrodes are flush with and grounded to the surface of the conducting beam tube; (2) the beam is a line source (pencil beam); (3) the longitudinal extent of the EM field of a beam particle at the beam tube wall is zero, corresponding to a highly relativistic beam. The purpose of this paper is to make some quantitative estimates of the corrections to the conventional approximations when a BPM is used to measure the position of low velocity (low-{beta}) beams.

  9. First results on the SPS beam collimation with bent crystals

    SciTech Connect (OSTI)

    Scandale, W.; Robert-Demolaize, G.; Arduini, G.; Assmann, R.; Bracco, C.; Gilardoni, S.; Ippolito, V.; Laface, E.; Losito, R,; Masi, A,; Metral, E,; Previtali, V.; Redaelli, S.; Silari, M.; Tlustos, L.; Bagli, E.; Baricordi, S.; Dalpiaz, P.; Guidi, V.; Mazzolari, A.; Vincenzi, D.; Della Mea, G.; Lombardi, A.; De Salvador, D.; Vallazza, E.; Bolognini, D.; Hasan, S.; Lietti, D.; Mascagna, V.; Mattera, A.; Prest, M.; Cavoto, G.; Ludovici, L.; Mirarchi, D.; Santacesaria, R.; Valente, P.; Murtas, F.; Afonin, A.G.; Chesnokov, Yu.A.; Maisheev, V.A.; Yazynin, I.A.; Kovalenko, A.D.; Taratin, A.M.; Denisov, A.S.; Gavrikov, Yu.A.; Ivanov, Yu.M.; Lapina, L.P.; Malyarenko, L.G.; Skorobogatov, V.V.; Suvorov, V.M.; Vavilov, S.A.; Mokhov, N.; Still, D.; Markiewicz, T.; Oriunno, M.

    2010-08-23

    Experiments were performed at the CERN SPS with 120 GeV/c stored proton beams to assess the possibility of beam halo collimation assisted by bent crystals. A bent crystal was used to deflect horizontally by an angle of about 170 {micro}rad the beam halo protons in channeling states directing them into a 60 cm long tungsten absorber. The halo loss rate due to nuclear inelastic interactions of protons in the aligned crystal was up to five times smaller than for its amorphous orientation. Channeled fractions, (75 {+-} 4)% and (85 {+-} 5)% for the two tested silicon crystals, were measured by intercepting the deflected beam with another collimator located between the crystals and the absorber. The pixel detector (MEDIPIX) installed in a Roman pot inside the beam pipe was used to obtain visual images of the deflected beam.

  10. SSRL Beam Lines Map | Stanford Synchrotron Radiation Lightsource

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

    SSRL Beam Lines Map Beam Line by Number | Beam Line by Techniques | Photon Source Parameters

  11. SSRL BEAM PORT SCHEDULE

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

    MC CHECKOUT8044 MC CHECKOUT9A91 MC CHECKOUT8837 AP DOWN DOWN 9A72 M.Deller 8044 I.Mathews 9A91 D.Das 8837 A.Cohen AP DOWN DOWN BEAM LINE 12-2 Dec. 14, 2015 Dec. 15, 2015 Dec....

  12. Pulsed ion beam source

    DOE Patents [OSTI]

    Greenly, J.B.

    1997-08-12

    An improved pulsed ion beam source is disclosed having a new biasing circuit for the fast magnetic field. This circuit provides for an initial negative bias for the field created by the fast coils in the ion beam source which pre-ionize the gas in the source, ionize the gas and deliver the gas to the proper position in the accelerating gap between the anode and cathode assemblies in the ion beam source. The initial negative bias improves the interaction between the location of the nulls in the composite magnetic field in the ion beam source and the position of the gas for pre-ionization and ionization into the plasma as well as final positioning of the plasma in the accelerating gap. Improvements to the construction of the flux excluders in the anode assembly are also accomplished by fabricating them as layered structures with a high melting point, low conductivity material on the outsides with a high conductivity material in the center. 12 figs.

  13. Beam current sensor

    DOE Patents [OSTI]

    Kuchnir, M.; Mills, F.E.

    1984-09-28

    A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

  14. Beam current sensor

    DOE Patents [OSTI]

    Kuchnir, Moyses (Elmhurst, IL); Mills, Frederick E. (Elburn, IL)

    1987-01-01

    A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

  15. SSRL BEAM PORT SCHEDULE

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

    BEAM LINE 7-1 Nov. 11, 2013 Nov. 12, 2013 Nov. 13, 2013 Nov. 14, 2013 Nov. 15, 2013 Nov. 16, 2013 Nov. 17, 2013 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith ...

  16. SSRL BEAM PORT SCHEDULE

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

    BEAM LINE 9-1 Feb. 14, 2005 Feb. 15, 2005 Feb. 16, 2005 Feb. 17, 2005 Feb. 18, 2005 Feb. 19, 2005 Feb. 20, 2005 8803 C.SMITH 8803 C.SMITHDOWN 9B01 A.DEACON 9B01 A.DEACON 1B00 ...

  17. SSRL BEAM PORT SCHEDULE

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

    BEAM LINE 7-1 Nov. 06, 2006 Nov. 07, 2006 Nov. 08, 2006 Nov. 09, 2006 Nov. 10, 2006 Nov. 11, 2006 Nov. 12, 2006 8803 C.SMITH 8803 C.SMITH 8803 C.SMITH 8803 C.SMITH 8803 C.SMITH ...

  18. SSRL BEAM PORT SCHEDULE

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

    BEAM LINE 9-1 Nov. 07, 2011 Nov. 08, 2011 Nov. 09, 2011 Nov. 10, 2011 Nov. 11, 2011 Nov. 12, 2011 Nov. 13, 2011 DOWN DOWN DOWN DOWN 8803 C.SMITH 8803 C.SMITH 8803 C.SMITH DOWN DOWN ...

  19. Optimizing the electron beam parameters for head-on beam-beam compensation in RHIC

    SciTech Connect (OSTI)

    Luo, Y.; Fischer, W.; Pikin, A.; Gu, X.

    2011-03-28

    Head-on beam-beam compensation is adopted to compensate the large beam-beam tune spread from the protonproton interactions at IP6 and IP8 in the Relativistic Heavy Ion Collider (RHIC). Two e-lenses are being built and to be in stalled near IP10 in the end of 2011. In this article we perform numeric simulation to investigate the effect of the electron beam parameters on the proton dynamics. The electron beam parameters include its transverse profile, size, current, offset and random errors in them. In this article we studied the effect of the electron beam parameters on the proton dynamics. The electron beam parameters include its transverse shape, size, current, offset and their random errors. From the study, we require that the electron beam size can not be smaller than the proton beam's. And the random noise in the electron current should be better than 0.1%. The offset of electron beam w.r.t. the proton beam center is crucial to head-on beam-beam compensation. Its random errors should be below {+-}8{micro}m.

  20. Neutral particle beam intensity controller

    DOE Patents [OSTI]

    Dagenhart, William K. (Oak Ridge, TN)

    1986-01-01

    A neutral beam intensity controller is provided for a neutral beam generator in which a neutral beam is established by accelerating ions from an ion source into a gas neutralizer. An amplitude modulated, rotating magnetic field is applied to the accelerated ion beam in the gas neutralizer to defocus the resultant neutral beam in a controlled manner to achieve intensity control of the neutral beam along the beam axis at constant beam energy. The rotating magnetic field alters the orbits of ions in the gas neutralizer before they are neutralized, thereby controlling the fraction of neutral particles transmitted out of the neutralizer along the central beam axis to a fusion device or the like. The altered path or defocused neutral particles are sprayed onto an actively cooled beam dump disposed perpendicular to the neutral beam axis and having a central open for passage of the focused beam at the central axis of the beamline. Virtually zero therough 100% intensity control is achieved by varying the magnetic field strength without altering the ion source beam intensity or its species yield.

  1. Beam position monitor sensitivity for low-[beta] beams

    SciTech Connect (OSTI)

    Shafer, R.E. )

    1994-10-10

    Design of a beam position monitor (BPM) which is sensitive to low velo charged particle beams is considered. Quantitative estimates are made for the corrections to the conventional approximations to solutions of the Laplace Equation in two-dimensions when a BPM is used to measure to position of low velocity (low-[beta]) beams. (AIP)

  2. The Beam | Open Energy Information

    Open Energy Info (EERE)

    Name: The Beam Place: Brookline, Massachusetts Zip: 2446 Product: The Beam is a start-up company that looks to establish an online retail portal that would market and sell...

  3. Laser beam pulse formatting method

    DOE Patents [OSTI]

    Daly, Thomas P. (Livermore, CA); Moses, Edward I. (Livermore, CA); Patterson, Ralph W. (Livermore, CA); Sawicki, Richard H. (Danville, CA)

    1994-01-01

    A method for formatting a laser beam pulse (20) using one or more delay loops (10). The delay loops (10) have a partially reflective beam splitter (12) and a plurality of highly reflective mirrors (14) arranged such that the laser beam pulse (20) enters into the delay loop (10) through the beam splitter (12) and circulates therein along a delay loop length (24) defined by the mirrors (14). As the laser beam pulse (20) circulates within the delay loop (10) a portion thereof is emitted upon each completed circuit when the laser beam pulse (20) strikes the beam splitter (12). The laser beam pulse (20) is thereby formatted into a plurality of sub-pulses (50, 52, 54 and 56). The delay loops (10) are used in combination to produce complex waveforms by combining the sub-pulses (50, 52, 54 and 56) using additive waveform synthesis.

  4. ANL Beams and Applications Seminar

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

    2010 2009 2008 2007 2006 2005 2004 2003 2002 2001 2000 1999 Seminar Sponsers AAI ASD ATLAS HEP PHY ANL Beams and Applications Seminar The ANL Beam and Applications Seminar is...

  5. Energy Spread of the Proton Beam in the Fermilab Booster at its Injection Energy

    SciTech Connect (OSTI)

    Bhat, C. M.; Chase, B. E.; Chaurize, S. J.; Garcia, F. G.; Seiya, K.; Pellico, W. A.; Sullivan, T. M.; Triplett, A. K.

    2015-04-27

    We have measured the energy spread of the Booster beam at its injection energy of 400 MeV by three different methods: (1) creating a notch of about 40 nsec wide in the beam immediately after multiple turn injection and measuring the slippage time required for high and low momentum particles for a grazing touch in line-charge distribution, (2) injecting partial turn beam and letting it to debunch, and (3) comparing the beam profile monitor data with predictions from MAD simulations for the 400 MeV injection beam line. The measurements are repeated under varieties of conditions of rf systems in the ring and in the beam transfer line.

  6. Method and apparatus for efficient photodetachment and purification of negative ion beams

    DOE Patents [OSTI]

    Beene, James R. [Oak Ridge, TN; Liu, Yuan [Knoxville, TN; Havener, Charles C. [Knoxville, TN

    2008-02-26

    Methods and apparatus are described for efficient photodetachment and purification of negative ion beams. A method of purifying an ion beam includes: inputting the ion beam into a gas-filled multipole ion guide, the ion beam including a plurality of ions; increasing a laser-ion interaction time by collisional cooling the plurality of ions using the gas-filled multipole ion guide, the plurality of ions including at least one contaminant; and suppressing the at least one contaminant by selectively removing the at least one contaminant from the ion beam by electron photodetaching at least a portion of the at least one contaminant using a laser beam.

  7. Laser beam guard clamps

    DOE Patents [OSTI]

    Dickson, Richard K. (Stockton, CA)

    2010-09-07

    A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

  8. SSRL BEAM PORT SCHEDULE

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

    1-4 Oct. 30, 2006 Oct. 31, 2006 Nov. 01, 2006 Nov. 02, 2006 Nov. 03, 2006 Nov. 04, 2006 Nov. 05, 2006 DOWN Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled BEAM LINE 2-1 Oct. 30, 2006 Oct. 31, 2006 Nov. 01, 2006 Nov. 02, 2006 Nov. 03, 2006 Nov. 04, 2006 Nov. 05, 2006 DOWN 8859 B.JOHNSON 8859 B.JOHNSON 8859

  9. Ion beam generating apparatus

    DOE Patents [OSTI]

    Brown, I.G.; Galvin, J.

    1987-12-22

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. 10 figs.

  10. Neutral Beam Excitation

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

    Beam Excitation of Alfv ´ en Continua in the Madison Symmetric Torus Reversed Field Pinch by Jonathan Jay Koliner A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Physics) at the University of Wisconsin - Madison 2013 Defended on 22 October 2013 Dissertation approved by the following members of the Final Oral Committee: Cary Forest * Professor of Physics John Sar↵ * Professor of Physics Jan Egedal * Professor of Physics Paul Terry *

  11. Ion beam generating apparatus

    DOE Patents [OSTI]

    Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); Galvin, James (2 Commodore #276, Emeryville, CA 94608)

    1987-01-01

    An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam.

  12. Stationary nonlinear Airy beams

    SciTech Connect (OSTI)

    Lotti, A.; Faccio, D.; Couairon, A.; Papazoglou, D. G.; Panagiotopoulos, P.; Tzortzakis, S.; Abdollahpour, D.

    2011-08-15

    We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.

  13. RadiaBeam PPT template

    Energy Savers [EERE]

    Pedro Frigola RadiaBeam Systems, LLC Advanced Methods for Manufacturing Workshop Lockheed Martin, September 29, 2015 Development of Nuclear Quality Components using Metal Additive Manufacturing  RadiaBeam overview  AM research at RadiaBeam  Overview of EBM AM technology  Goals and relevance of the Phase I/II project  Phase I/II work 09/29/2015 2015 AMM Workshop - P. Frigola, RadiaBeam Systems, LLC 2 Outline  RadiaBeam has two core missions:  To manufacture high quality,

  14. Longitudinal Diagnostics for Short Electron Beam Bunches

    SciTech Connect (OSTI)

    Loos, H.; ,

    2010-06-11

    Single-pass free electron lasers require high peak currents from ultra-short electron bunches to reach saturation and an accurate measurement of bunch length and longitudinal bunch profile is necessary to control the bunch compression process from low to high beam energy. The various state-of-the-art diagnostics methods from ps to fs time scales using coherent radiation detection, RF deflection, and other techniques are presented. The use of linear accelerators as drivers for free electron lasers (FEL) and the advent of single-pass (SASE) FELs has driven the development of a wide range of diagnostic techniques for measuring the length and longitudinal distribution of short and ultra-short electron bunches. For SASE FELs the radiation power and the length of the undulator needed to achieve saturation depend strongly on the charge density of the electron beam. In the case of X-ray FELs, this requires the accelerator to produce ultra-high brightness beams with micron size transverse normalized emittances and peak currents of several kA through several stages of magnetic bunch compression. Different longitudinal diagnostics are employed to measure the peak current and bunch profile along these stages. The measurement techniques can be distinguished into different classes. Coherent methods detect the light emitted from the beam by some coherent radiation process (spectroscopic measurement), or directly measure the Coulomb field traveling with the beam (electro-optic). Phase space manipulation techniques map the time coordinate onto a transverse dimension and then use conventional transverse beam diagnostics (transverse deflector, rf zero-phasing). Further methods measure the profile or duration of an incoherent light pulse emitted by the bunch at wavelengths much shorted than the bunch length (streak camera, fluctuation technique) or modulate the electron beam at an optical wavelength and then generate a narrow bandwidth radiation pulse with the longitudinal profile of the beam mapped onto (optical replicator). The operational needs for bunch length measurements to have fast acquisitions, to be used in feedback systems, to distinguish pulse to pulse changes and to be nondestructive or parasitically have resulted into developing many of the diagnostics into single-shot techniques and in the following the main discussion will emphasize them.

  15. Laser beam characterization results for a high power CW Nd:YAG laser

    SciTech Connect (OSTI)

    Keicher, D.M.

    1994-12-31

    In an effort to understand multimode laser beam propagation characteristics for better development of laser material processing applications, beam diagnostic experiments were performed on a 1800 watt CW Nd:YAG laser. Beam diameter data were acquired at approximately 12 positions along the beam optical axis about the minimum waist created by a long focal length single element lens at several power levels. These data were then used to evaluate the laser output beam characteristics using two differing techniques. For the ISO technique, two data points from the beam diameter data were used in determining the output laser beam characteristics. These points were the beam minimum waist diameter and the diameter at a point along the beam optical axis where the beam diameter had increased to approximately 0.7 times that of the beam minimum waist diameter. The second analysis technique involved fitting the entire data set to theoretical equations used to describe the multimode laser beam propagation and points from the fitted curve fit were then used to determine the output beam characteristics from the laser. For all power levels evaluated, calculated results predicting the laser beam minimum waist location were in agreement with measured values and more consistent using the curve-fit technique than the two-point evaluation technique.

  16. Arc-based smoothing of ion beam intensity on targets

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

    Friedman, Alex

    2012-06-20

    Manipulating a set of ion beams upstream of a target, makes it possible to arrange a smoother deposition pattern, so as to achieve more uniform illumination of the target. A uniform energy deposition pattern is important for applications including ion-beam-driven high energy density physics and heavy-ion beam-driven inertial fusion energy (“heavy-ion fusion”). Here, we consider an approach to such smoothing that is based on rapidly “wobbling” each of the beams back and forth along a short arc-shaped path, via oscillating fields applied upstream of the final pulse compression. In this technique, uniformity is achieved in the time-averaged sense; this ismore » sufficient provided the beam oscillation timescale is short relative to the hydrodynamic timescale of the target implosion. This work builds on two earlier concepts: elliptical beams applied to a distributed-radiator target [D. A. Callahan and M. Tabak, Phys. Plasmas 7, 2083 (2000)] and beams that are wobbled so as to trace a number of full rotations around a circular or elliptical path [R. C. Arnold et al., Nucl. Instrum. Methods 199, 557 (1982)]. Here, we describe the arc-based smoothing approach and compare it to results obtainable using an elliptical-beam prescription. In particular, we assess the potential of these approaches for minimization of azimuthal asymmetry, for the case of a ring of beams arranged on a cone. We also found that, for small numbers of beams on the ring, the arc-based smoothing approach offers superior uniformity. In contrast with the full-rotation approach, arc-based smoothing remains usable when the geometry precludes wobbling the beams around a full circle, e.g., for the X-target [E. Henestroza, B. G. Logan, and L. J. Perkins, Phys. Plasmas 18, 032702 (2011)] and some classes of distributed-radiator targets.« less

  17. RECENT EXPERIENCE WITH ELECTRON LENS BEAM-BEAM COMPENSATION AT...

    Office of Scientific and Technical Information (OSTI)

    with use of bent crystals and pulsed dipole deflectors (orbit correctors). The angular beam deflection by the crystal - see Fig.2 - must be large enough to send the...

  18. Beam transfer and extraction at LAMPF II

    SciTech Connect (OSTI)

    Colton, E.P.

    1983-01-01

    Protons will be single-turn extracted from the LAMPF II synchrotron at 30 Hz. On alternate pulses they will be single-turn injected into a storage ring. Both processes utilize fast kickers and Lambertson septum magnets. Half-integer resonant extraction will be used to slow-extract the beam from the storage ring over a time spread of 1/15 s. The slow extraction occurs using electrostatic wire and iron septa.

  19. Beam experiments related to the head-on beam-beam compensation project at RHIC

    SciTech Connect (OSTI)

    Montag, C.; Bai, M.; Drees, A.; Fischer, W.; Marusic, A.; Wang, G.

    2011-03-28

    Beam experiments have been performed in RHIC to determine some key parameters of the RHIC electron lenses, and to test the capability of verifying lattice modifications by beam measurements. We report the status and recent results of these experiments. The Relativistic Heavy Ion Collider (RHIC) consists of two superconducting storage rings that intersect at six locations around its circumference. Beams collide in interaction points (IPs) 6 and 8, which are equipped with the detectors STAR and PHENIX, respectively (Fig. 1). With the polarized proton working point constrained between 2/3 and 7/10 to achieve good luminosity lifetime and maintain polarization, the proton bunch intensity is limited to 2 {center_dot} 10{sup 11} protons per bunch by the resulting beam-beam tuneshift. To overcome this limitation, installation of an electron lens in IP 10 is foreseen to partially compensate the beam-beam effect and reduce the beam-beam tuneshift parameter. As part of this project, beam experiments are being performed at RHIC to determine key parameters of the electron lens as well as to verify lattice modifications.

  20. Beam characterization by wavefront sensor

    DOE Patents [OSTI]

    Neal, Daniel R. (17 Eric Alan Lane, Tijeras, NM 87059); Alford, W. J. (3455 Tahoe, N.E., Albuquerque, NM 87111); Gruetzner, James K. (9407 Shoehone, N.E., Albuquerque, NM 87111)

    1999-01-01

    An apparatus and method for characterizing an energy beam (such as a laser) with a two-dimensional wavefront sensor, such as a Shack-Hartmann lenslet array. The sensor measures wavefront slope and irradiance of the beam at a single point on the beam and calculates a space-beamwidth product. A detector array such as a charge coupled device camera is preferably employed.

  1. Beam characterization by wavefront sensor

    DOE Patents [OSTI]

    Neal, D.R.; Alford, W.J.; Gruetzner, J.K.

    1999-08-10

    An apparatus and method are disclosed for characterizing an energy beam (such as a laser) with a two-dimensional wavefront sensor, such as a Shack-Hartmann lenslet array. The sensor measures wavefront slope and irradiance of the beam at a single point on the beam and calculates a space-beamwidth product. A detector array such as a charge coupled device camera is preferably employed. 21 figs.

  2. Broad-band beam buncher

    DOE Patents [OSTI]

    Goldberg, David A. (Walnut Creek, CA); Flood, William S. (Berkeley, CA); Arthur, Allan A. (Martinez, CA); Voelker, Ferdinand (Orinda, CA)

    1986-01-01

    A broad-band beam buncher is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-band response and the device as a whole designed to effect broad-band beam coupling, so as to minimize variations of the output across the response band.

  3. Positron lifetime spectrometer using a DC positron beam

    DOE Patents [OSTI]

    Xu, Jun; Moxom, Jeremy

    2003-10-21

    An entrance grid is positioned in the incident beam path of a DC beam positron lifetime spectrometer. The electrical potential difference between the sample and the entrance grid provides simultaneous acceleration of both the primary positrons and the secondary electrons. The result is a reduction in the time spread induced by the energy distribution of the secondary electrons. In addition, the sample, sample holder, entrance grid, and entrance face of the multichannel plate electron detector assembly are made parallel to each other, and are arranged at a tilt angle to the axis of the positron beam to effectively separate the path of the secondary electrons from the path of the incident positrons.

  4. The performance of the MICE muon beam line

    SciTech Connect (OSTI)

    Rayner, Mark Alastair

    2011-10-06

    The Muon Ionization Cooling Experiment is one lattice cell of a cooling channel suitable for conditioning the muon beam at the front end of a Neutrino Factory or Muon Collider. The beam line designed to transport muons into MICE has been installed, and data was collected in 2010. In this paper the method of reconstructing longitudinal momentum and transverse trace space using two timing detectors is discussed, and a preliminary simulation of the performance of a measured beam in the cooling channel is presented.

  5. Apparatus and method for increasing the bandwidth of a laser beam

    DOE Patents [OSTI]

    Chaffee, Paul H. (Bolina, CA)

    1991-01-01

    A method and apparatus is disclosed that provides a laser output beam having a broad bandwidth and an intensity smooth over time. The bandwidth of the laser output can be varied easily by varying the intensity of a broadband source. The present invention includes an optical modulation apparatus comprising a narrowband laser that outputs a horizontally polarized beam (a "signal beam") and a broadband laser that outputs a vertically polarized beam (a "pump beam") whose intensity varies rapidly. The two beam are coupled into a birefringent laser material so that the respective polarizations coincide with the principal axes of the material. As the two beams travel through the material, the polarization preserving properties of the birefringent material maintain the respective polarizations of the two beam; however there is coupling between the two beams as a result of cross phase modulations, which induces a bandwidth change of the signal beam. The amount of bandwidth change is dependent upon the average intensity of the pump beam. The beams are coupled out from the birefringent material and the modulated signal beam is separated by a polarization selector. The modulated signal beam now has a wider bandwidth, and its shape remains smooth in time. This signal beam can be applied to incoherence inducing systems. The different bandwidths required by these different incoherence inducing systems can be obtained by varying the intensity of the pump beam. The United States Government has rights in this invention pursuant to Contract No. W7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.

  6. Cherenkov Light-based Beam Profiling for Ultrarelativistic Electron Beams

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

    Adli, E.; Gessner, S. J.; Corde, S.; Hogan, M. J.; Bjerke, H. H.

    2015-02-09

    We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design allows for measuring large beam sizes, with large photon yield per beam charge and excellent signal linearity with beam charge. Furthermore, the profile monitor signal is independent of the particle energy for ultrarelativistic particles. Different design and parameter considerations are discussed. A Cherenkov light-based profile monitor has been installed at the FACET User Facility at SLAC. Finally,more » we report on the measured performance of this profile monitor.« less

  7. Development of a fast position-sensitive laser beam detector

    SciTech Connect (OSTI)

    Chavez, Isaac; Huang Rongxin; Henderson, Kevin; Florin, Ernst-Ludwig; Raizen, Mark G. [Center for Nonlinear Dynamics and Department of Physics, University of Texas at Austin, Austin, Texas 78712 (United States)

    2008-10-15

    We report the development of a fast position-sensitive laser beam detector. The detector uses a fiber-optic bundle that spatially splits the incident beam, followed by a fast balanced photodetector. The detector is applied to the study of Brownian motion of particles on fast time scales with 1 A spatial resolution. Future applications include the study of molecule motors, protein folding, as well as cellular processes.

  8. SSRL BEAM PORT SCHEDULE

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

    1-5 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ BEAM LINE 7-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec.

  9. SSRL BEAM PORT SCHEDULE

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

    5 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 9-1 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 Unscheduled CHANGE/8837 A.COHE 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN Unscheduled 8837 A.COHEN/DOWN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837

  10. SSRL BEAM PORT SCHEDULE

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

    7-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ MC CHECKOUT/2B87 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA BEAM LINE 9-1 Nov. 15, 2010 Nov. 16,

  11. SSRL BEAM PORT SCHEDULE

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

    5-4 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU BEAM LINE 8-1 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN DOWN DOWN DOWN DOWN 3064 S.SUN 3064 S.SUN DOWN DOWN DOWN DOWN VUV CHECKOUT

  12. SSRL BEAM PORT SCHEDULE

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

    5-4 Oct. 26, 2009 Oct. 27, 2009 Oct. 28, 2009 Oct. 29, 2009 Oct. 30, 2009 Oct. 31, 2009 Nov. 01, 2009 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU 8820* D.LU BEAM LINE 8-1 Oct. 26, 2009 Oct. 27, 2009 Oct. 28, 2009 Oct. 29, 2009 Oct. 30, 2009 Oct. 31, 2009 Nov. 01, 2009 Unscheduled Unscheduled Unscheduled Unscheduled

  13. SSRL BEAM PORT SCHEDULE

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

    5-4 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU BEAM LINE 8-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 Unscheduled Unscheduled Unscheduled 3269 S.SUN 3269 S.SUN 3269 S.SUN 3269

  14. SSRL BEAM PORT SCHEDULE

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

    1-4 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled Unscheduled 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY Unscheduled CHANGE/8051 M.TONE 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY Unscheduled 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY BEAM LINE 2-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 8859

  15. SSRL BEAM PORT SCHEDULE

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

    1-4 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 2-1 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN 8859 B.JOHNSON 8051* M.TONEY 8051* M.TONEY 8051* M.TONEY 3205 M.BIBEE 3205 M.BIBEE Xray CHECKOUT/8859 CHANGE/8051* M.TON 8051* M.TONEY 8051* M.TONEY Xray CHECKOUT/3205 3205

  16. Molecular-beam scattering

    SciTech Connect (OSTI)

    Vernon, M.F.

    1983-07-01

    The molecular-beam technique has been used in three different experimental arrangements to study a wide range of inter-atomic and molecular forces. Chapter 1 reports results of a low-energy (0.2 kcal/mole) elastic-scattering study of the He-Ar pair potential. The purpose of the study was to accurately characterize the shape of the potential in the well region, by scattering slow He atoms produced by expanding a mixture of He in N/sub 2/ from a cooled nozzle. Chapter 2 contains measurements of the vibrational predissociation spectra and product translational energy for clusters of water, benzene, and ammonia. The experiments show that most of the product energy remains in the internal molecular motions. Chapter 3 presents measurements of the reaction Na + HCl ..-->.. NaCl + H at collision energies of 5.38 and 19.4 kcal/mole. This is the first study to resolve both scattering angle and velocity for the reaction of a short lived (16 nsec) electronic excited state. Descriptions are given of computer programs written to analyze molecular-beam expansions to extract information characterizing their velocity distributions, and to calculate accurate laboratory elastic-scattering differential cross sections accounting for the finite apparatus resolution. Experimental results which attempted to determine the efficiency of optically pumping the Li(2/sup 2/P/sub 3/2/) and Na(3/sup 2/P/sub 3/2/) excited states are given. A simple three-level model for predicting the steady-state fraction of atoms in the excited state is included.

  17. Method and apparatus for monitoring the power of a laser beam

    DOE Patents [OSTI]

    Paris, Robert D. (San Ramon, CA); Hackel, Richard P. (Livermore, CA)

    1996-01-01

    A method for monitoring the power of a laser beam in real time is disclosed. At least one optical fiber is placed through the laser beam, where a portion of light from the laser beam is coupled into the optical fiber. The optical fiber may be maintained in a stationary position or moved periodically over a cross section of the laser beam to couple light from each area traversed. Light reaching both fiber ends is monitored according to frequency and processed to determine the power of the laser beam.

  18. Broad-band beam buncher

    DOE Patents [OSTI]

    Goldberg, D.A.; Flood, W.S.; Arthur, A.A.; Voelker, F.

    1984-03-20

    A broad-band beam bunther is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-

  19. Nuclear Physics: Experiment Research - Call for Beam Time Requests

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

    Scheduling Process The Experiment Scheduling Committee will tentatively meet twice a year. In September to reaffirm the schedule for the period January 1 - June 30, and to release both the firm schedule for the period July 1 - December 31 and the tentative schedule for the period January 1 - June 30 of the following year. They will also meet in March to reaffirm the schedule for the period July 1 - December 31, and to release both the firm schedule for the period January 1 - June 30 of the

  20. Nuclear Physics: Experiment Research - Call for Beam Time Requests

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

    Free-Electron Laser (FEL) Medical Imaging Physics Topics Campaigns Meetings Recent Talks ... Jefferson Lab Users Group From : Nuclear Physics Experiment Scheduling Committee Subject: ...

  1. Nuclear Physics: Experiment Research - Call for Beam Time Requests

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

    develop the goals for each acceleratorphysics running cycle, develop the schedule for ... The Scheduling Committee will consider the physics priority of each experiment, together ...

  2. How to Request & Access Beam Time | Stanford Synchrotron Radiation...

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

    who were born in, are citizens of, or have affiliations with organizations from Cuba, Iran, Sudan or Syria, we must collect additional information and obtain ADVANCE...

  3. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    SciTech Connect (OSTI)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G.; Singh, P.

    2013-12-15

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  4. High gradient lens for charged particle beam

    DOE Patents [OSTI]

    Chen, Yu-Jiuan

    2014-04-29

    Methods and devices enable shaping of a charged particle beam. A dynamically adjustable electric lens includes a series of alternating a series of alternating layers of insulators and conductors with a hollow center. The series of alternating layers when stacked together form a high gradient insulator (HGI) tube to allow propagation of the charged particle beam through the hollow center of the HGI tube. A plurality of transmission lines are connected to a plurality of sections of the HGI tube, and one or more voltage sources are provided to supply an adjustable voltage value to each transmission line of the plurality of transmission lines. By changing the voltage values supplied to each section of the HGI tube, any desired electric field can be established across the HGI tube. This way various functionalities including focusing, defocusing, acceleration, deceleration, intensity modulation and others can be effectuated on a time varying basis.

  5. Depolarization due to beam-beam interaction in electron-positron linear

    Office of Scientific and Technical Information (OSTI)

    colliders (Conference) | SciTech Connect Conference: Depolarization due to beam-beam interaction in electron-positron linear colliders Citation Details In-Document Search Title: Depolarization due to beam-beam interaction in electron-positron linear colliders We investigate two major mechanisms which induce depolarization of electron beams during beam-beam interaction in linear colliders. These are the classical spin precession under the collective field of the oncoming beam, and the

  6. Properties of Inconel 625 Mesh Structures Grown by Electron Beam...

    Office of Scientific and Technical Information (OSTI)

    Relationships between electron beam parameters (beam current, beam speed, and beam focus) ... Simple models have been used to understand better these relationships. Structural ...

  7. BEAM-BEAM SIMULATIONS FOR THE ERHIC ELECTRON RING.

    SciTech Connect (OSTI)

    MONTAG, C.

    2005-05-16

    To study collisions between polarized electrons and heavy ions or polarized protons at high energy, adding a 10 GeV electron storage ring to the existing RHIC facility is currently under consideration. To achieve high luminosities of several 10{sup 33} cm{sup -2} sec{sup -1} range, a vertical beam-beam tuneshift parameter of {zeta}{sub y} = 0.08 is required for the electron beam. Simulation studies are being performed to study the feasibility of this high tuneshift parameter and explore the potential for even higher tuneshifts. Recent results of these studies are presented.

  8. Light beam range finder

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-01-01

    A "laser tape measure" for measuring distance which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%.

  9. Light beam range finder

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-06-16

    A ``laser tape measure`` for measuring distance is disclosed which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%. 7 figs.

  10. Laser beam alignment apparatus and method

    DOE Patents [OSTI]

    Gruhn, Charles R.; Hammond, Robert B.

    1981-01-01

    The disclosure relates to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  11. Laser beam alignment apparatus and method

    DOE Patents [OSTI]

    Gruhn, C.R.; Hammond, R.B.

    The disclosure related to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  12. Coherent instabilities of a relativistic bunched beam

    SciTech Connect (OSTI)

    Chao, A.W.

    1982-06-01

    A charge-particle beam contained in an accelerator vacuum chamber interacts electromagnetically with its environment to create a wake field. This field than acts back on the beam, perturbing the particle motion. If the beam intensity is high enough, this beam-environment interaction may lead to an instability and to subsequent beam loss. The beam and its environment form a dynamical system, and it is this system that will be studied. 84 references.

  13. Electrostatic wire stabilizing a charged particle beam

    DOE Patents [OSTI]

    Prono, D.S.; Caporaso, G.J.; Briggs, R.J.

    1983-03-21

    In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

  14. System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)

    DOE Patents [OSTI]

    Skupsky, Stanley (Rochester, NY); Kessler, Terrance J. (Rochester, NY); Short, Robert W. (Rochester, NY); Craxton, Stephen (Rochester, NY); Letzring, Samuel A. (Honeoye Falls, NY); Soures, John (Pittsford, NY)

    1991-01-01

    In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies ("colors") cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers.

  15. Systems for controlling the intensity variations in a laser beam and for frequency conversion thereof

    DOE Patents [OSTI]

    Skupsky, S.; Craxton, R.S.; Soures, J.

    1990-10-02

    In order to control the intensity of a laser beam so that its intensity varies uniformly and provides uniform illumination of a target, such as a laser fusion target, a broad bandwidth laser pulse is spectrally dispersed spatially so that the frequency components thereof are spread apart. A disperser (grating) provides an output beam which varies spatially in wavelength in at least one direction transverse to the direction of propagation of the beam. Temporal spread (time delay) across the beam is corrected by using a phase delay device (a time delay compensation echelon). The dispersed beam may be amplified with laser amplifiers and frequency converted (doubled, tripled or quadrupled in frequency) with nonlinear optical elements (birefringent crystals). The spectral variation across the beam is compensated by varying the angle of incidence on one of the crystals with respect to the crystal optical axis utilizing a lens which diverges the beam. Another lens after the frequency converter may be used to recollimate the beam. The frequency converted beam is recombined so that portions of different frequency interfere and, unlike interference between waves of the same wavelength, there results an intensity pattern with rapid temporal oscillations which average out rapidly in time thereby producing uniform illumination on target. A distributed phase plate (also known as a random phase mask), through which the spectrally dispersed beam is passed and then focused on a target, is used to provide the interference pattern which becomes nearly modulation free and uniform in intensity in the direction of the spectral variation. 16 figs.

  16. Systems for controlling the intensity variations in a laser beam and for frequency conversion thereof

    DOE Patents [OSTI]

    Skupsky, Stanley (Rochester, NY); Craxton, R. Stephen (Rochester, NY); Soures, John (Pittsford, NY)

    1990-01-01

    In order to control the intensity of a laser beam so that its intensity varies uniformly and provides uniform illumination of a target, such as a laser fusion target, a broad bandwidth laser pulse is spectrally dispersed spatially so that the frequency components thereof are spread apart. A disperser (grating) provides an output beam which varies spatially in wavelength in at least one direction transverse to the direction of propagation of the beam. Temporal spread (time delay) across the beam is corrected by using a phase delay device (a time delay compensation echelon). The dispersed beam may be amplified with laser amplifiers and frequency converted (doubled, tripled or quadrupled in frequency) with nonlinear optical elements (birefringent crystals). The spectral variation across the beam is compensated by varying the angle of incidence on one of the crystals with respect to the crystal optical axis utilizing a lens which diverges the beam. Another lens after the frequency converter may be used to recollimate the beam. The frequency converted beam is recombined so that portions of different frequency interfere and, unlike interference between waves of the same wavelength, there results an intensity pattern with rapid temoral oscillations which average out rapidly in time thereby producing uniform illumination on target. A distributed phase plate (also known as a random phase mask), through which the spectrally dispersed beam is passed and then focused on a target, is used to provide the interference pattern which becomes nearly modulation free and uniform in intensity in the direction of the spectral variation.

  17. Expanded beam deflection method for simultaneous measurement of displacement and vibrations of multiple microcantilevers

    SciTech Connect (OSTI)

    Nieradka, K.; MaloziePc, G.; Kopiec, D.; Gotszalk, T.

    2011-10-15

    Here we present an extension of optical beam deflection (OBD) method for measuring displacement and vibrations of an array of microcantilevers. Instead of focusing on the cantilever, the optical beam is either focused above or below the cantilever array, or focused only in the axis parallel to the cantilevers length, allowing a wide optical line to span multiple cantilevers in the array. Each cantilever reflects a part of the incident beam, which is then directed onto a photodiode array detector in a manner allowing distinguishing between individual beams. Each part of reflected beam behaves like a single beam of roughly the same divergence angle in the bending sensing axis as the incident beam. Since sensitivity of the OBD method depends on the divergence angle of deflected beam, high sensitivity is preserved in proposed expanded beam deflection (EBD) method. At the detector, each spot's position is measured at the same time, without time multiplexing of light sources. This provides real simultaneous readout of entire array, unavailable in most of competitive methods, and thus increases time resolution of the measurement. Expanded beam can also span another line of cantilevers allowing monitoring of specially designed two-dimensional arrays. In this paper, we present first results of application of EBD method to cantilever sensors. We show how thermal noise resolution can be easily achieved and combined with thermal noise based resonance frequency measurement.

  18. CONTINUOUS EXTRACTED BEAM IN THE AGS FAST EXTERNAL BEAM LINE.

    SciTech Connect (OSTI)

    GLENN,J.W.; TSOUPAS,N.; BROWN,K.A.; BIRYUKOV,V.M.

    2001-06-18

    A method to split off a few percent of the 6 x 10{sup 13} AGS beam delivered to the Slow External Beam (SEB) lines and send it down the Fast External Beam line (FEB) has been developed. The mission is to feed a counter experiment off the FEB that directly measures the neutrino mass using the muon storage ring. The use of normal thin septum splitters would have an excessive loss overhead and been optically difficult. The AGS Slow Extraction uses a third integer resonance with sextuple strength so the resonance width is a few percent of the beam width. This results in a low density tail which will be clipped by a bent crystal and deflected into the FEB channel. This clipping off of the tail should reduce losses in the SEB transport line. Details of modeled orbits, particle distribution and extraction trajectories into and out off the crystal will be given.

  19. Electron beam machining using rotating and shaped beam power distribution

    DOE Patents [OSTI]

    Elmer, J.W.; O`Brien, D.W.

    1996-07-09

    An apparatus and method are disclosed for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: (1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and (2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1,000 {micro}m (1 mm or larger), compared to the 250 {micro}m diameter of laser drilling. 5 figs.

  20. Electron beam machining using rotating and shaped beam power distribution

    DOE Patents [OSTI]

    Elmer, John W. (Pleasanton, CA); O'Brien, Dennis W. (Livermore, CA)

    1996-01-01

    An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

  1. SU-E-T-568: Improving Normal Brain Sparing with Increasing Number of Arc Beams for Volume Modulated Arc Beam Radiosurgery of Multiple Brain Metastases

    SciTech Connect (OSTI)

    Hossain, S; Hildebrand, K; Ahmad, S; Larson, D; Ma, L; Sahgal, A

    2014-06-01

    Purpose: Intensity modulated arc beams have been newly reported for treating multiple brain metastases. The purpose of this study was to determine the variations in the normal brain doses with increasing number of arc beams for multiple brain metastases treatments via the TrueBeam Rapidarc system (Varian Oncology, Palo Alto, CA). Methods: A patient case with 12 metastatic brain lesions previously treated on the Leksell Gamma Knife Perfexion (GK) was used for the study. All lesions and organs at risk were contoured by a senior radiation oncologist and treatment plans for a subset of 3, 6, 9 and all 12 targets were developed for the TrueBeam Rapidarc system via 3 to 7 intensity modulated arc-beams with each target covered by at least 99% of the prescribed dose of 20 Gy. The peripheral normal brain isodose volumes as well as the total beam-on time were analyzed with increasing number of arc beams for these targets. Results: All intensisty modulated arc-beam plans produced efficient treatment delivery with the beam-on time averaging 0.6–1.5 min per lesion at an output of 1200 MU/min. With increasing number of arc beams, the peripheral normal brain isodose volumes such as the 12-Gy isodose line enclosed normal brain tissue volumes were on average decreased by 6%, 11%, 18%, and 28% for the 3-, 6-, 9-, 12-target treatment plans respectively. The lowest normal brain isodose volumes were consistently found for the 7-arc treatment plans for all the cases. Conclusion: With nearly identical beam-on times, the peripheral normal brain dose was notably decreased when the total number of intensity modulated arc beams was increased when treating multiple brain metastases. Dr Sahgal and Dr Ma are currently serving on the board of international society of stereotactic radiosurgery.

  2. Probing Organic Transistors with Infrared Beams

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

    Probing Organic Transistors with Infrared Beams Probing Organic Transistors with Infrared Beams Print Wednesday, 26 July 2006 00:00 Silicon-based transistors are well-understood,...

  3. Ion Beams - Radiation Effects Facility / Cyclotron Institute...

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

    Useful Graphs Various ion beams have been developed specifically for the Radiation Effects Facility. These beams provide for a wide scope of LET with high energies for...

  4. Tomographic determination of the power distribution in electron beams

    DOE Patents [OSTI]

    Teruya, Alan T. (Livermore, CA); Elmer, John W. (Pleasanton, CA)

    1996-01-01

    A tomographic technique for determining the power distribution of an electron beam using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. A refractory metal disk with a number of radially extending slits is placed above a Faraday cup. The beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. Also, a single computer is used to generate the signals actuating the sweep, to acquire that data, and to do the reconstruction, thus reducing the time and equipment necessary to complete the process.

  5. Tomographic determination of the power distribution in electron beams

    DOE Patents [OSTI]

    Teruya, A.T.; Elmer, J.W.

    1996-12-10

    A tomographic technique for determining the power distribution of an electron beam using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams is disclosed. A refractory metal disk with a number of radially extending slits is placed above a Faraday cup. The beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. Also, a single computer is used to generate the signals actuating the sweep, to acquire that data, and to do the reconstruction, thus reducing the time and equipment necessary to complete the process. 4 figs.

  6. Beam Fields in an Integrated Cavity, Coupler and Window Configuration

    SciTech Connect (OSTI)

    Weathersby, Stephen; Novokhatski, Alexander; /SLAC

    2010-02-10

    In a multi-bunch high current storage ring, beam generated fields couple strongly into the RF cavity coupler structure when beam arrival times are in resonance with cavity fields. In this study the integrated effect of beam fields over several thousand RF periods is simulated for the complete cavity, coupler, window and waveguide system of the PEP-II B-factory storage ring collider. We show that the beam generated fields at frequencies corresponding to several bunch spacings for this case gives rise to high field strength near the ceramic window which could limit the performance of future high current storage rings such as PEP-X or Super B-factories.

  7. Observations and open questions in beam-beam interactions

    SciTech Connect (OSTI)

    Sen, Tanaji; /Fermilab

    2010-08-01

    The first of the hadron colliders, ISR, started operation in 1970. In the following years, the hadron colliders to follow were the SPS (started 1980), the Tevatron (started 1987 first as a fixed target machine), RHIC (started 2000) and most recently the LHC, which started in 2008. HERA was a hybrid that collided electrons and protons. All of these accelerators had or have their performance limited by the effects of the beam-beam interactions. That has also been true for the electron-positron colliders such as LEP, CESR, KEKB and PEPII. In this article I will discuss how the beam-beam limitations arose in some of these machines. The discussion will be focused on common themes that span the different colliders. I will mostly discuss the hadron colliders but sometimes discuss the lepton colliders where relevant. Only a handful of common accelerator physics topics are chosen here, the list is not meant to be exhaustive. A comparative review of beam-beam performance in the ISR, SPS and Tevatron (ca 1989) can be found in reference. Table 1 shows the relevant parameters of colliders (excluding the LHC), which have accelerated protons.

  8. Tevatron injection timing

    SciTech Connect (OSTI)

    Saritepe, S.; Annala, G.

    1993-06-01

    Bunched beam transfer from one accelerator to another requires coordination and synchronization of many ramped devices. During collider operation timing issues are more complicated since one has to switch from proton injection devices to antiproton injection devices. Proton and antiproton transfers are clearly distinct sequences since protons and antiprotons circulate in opposite directions in the Main Ring (MR) and in the Tevatron. The time bumps are different, the kicker firing delays are different, the kickers and lambertson magnets are different, etc. Antiprotons are too precious to be used for tuning purposes, therefore protons are transferred from the Tevatron back into the Main Ring, tracing the path of antiprotons backwards. This tuning operation is called ``reverse injection.`` Previously, the reverse injection was handled in one supercycle. One batch of uncoalesced bunches was injected into the Tevatron and ejected after 40 seconds. Then the orbit closure was performed in the MR. In the new scheme the lambertson magnets have to be moved and separator polarities have to be switched, activities that cannot be completed in one supercycle. Therefore, the reverse injection sequence was changed. This involved the redefinition of TVBS clock event $D8 as MRBS $D8 thus making it possible to inject 6 proton batches (or coalesced bunches) and eject them one at a time on command, performing orbit closure each time in the MR. Injection devices are clock event driven. The TCLK is used as the reference clock. Certain TCLK events are triggered by the MR beam synchronized clock (MRBS) events. Some delays are measured in terms of MRBS ticks and MR revolutions. See Appendix A for a brief description of the beam synchronized clocks.

  9. Circular, confined distribution for charged particle beams

    DOE Patents [OSTI]

    Garnett, Robert W. (Los Alamos, NM); Dobelbower, M. Christian (Toledo, OH)

    1995-01-01

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location.

  10. Circular, confined distribution for charged particle beams

    DOE Patents [OSTI]

    Garnett, R.W.; Dobelbower, M.C.

    1995-11-21

    A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location. 26 figs.

  11. Quantum fluctuations in beam dynamics.

    SciTech Connect (OSTI)

    Kim, K.-J.

    1998-06-04

    Quantum effects could become important for particle and photon beams used in high-luminosity and high brightness applications in the current and next generation accelerators and radiation sources. This paper is a review of some of these effects.

  12. The Fermilab neutrino beam program

    SciTech Connect (OSTI)

    Rameika, Regina A.; /Fermilab

    2007-01-01

    This talk presents an overview of the Fermilab Neutrino Beam Program. Results from completed experiments as well as the status and outlook for current experiments is given. Emphasis is given to current activities towards planning for a future program.

  13. 6-D weak-strong beam-beam simulation study of proton lifetime in presence of head-on beam-beam compensation in the RHIC

    SciTech Connect (OSTI)

    Luo, Y.; Fischer, W.

    2010-08-01

    In this note we summarize the calculated particle loss of a proton bunch in the presence of head-on beam-beam compensation in the Relativistic Heavy Ion Collider (RHIC). To compensate the head-on beam-beam effect in the RHIC 250 GeV polarized proton run, we are introducing a DC electron beam with the same transverse profile as the proton beam to collide with the proton beam. Such a device is called an electron lens (e-lens). In this note we first present the optics and beam parameters and the tracking setup. Then we calculate and compare the particle loss of a proton bunch with head-on beam-beam compensation, phase advance of k{pi} between IP8 and the center of the e-lens and second order chromaticity correction. We scanned the proton beam's linear chromaticity, working point and bunch intensity. We also scanned the electron beam's intensity, transverse beam size. The effect of the electron-proton transverse offset in the e-lens was studied. In the study 6-D weak-strong beam-beam interaction model a la Hirata is used for proton collisions at IP6 and IP8. The e-lens is modeled as 8 slices. Each slice is modeled with as drift - (4D beam-beam kick) - drift.

  14. Confined energy distribution for charged particle beams

    DOE Patents [OSTI]

    Jason, Andrew J.; Blind, Barbara

    1990-01-01

    A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

  15. Intense Ion Beam for Warm Dense Matter Physics

    SciTech Connect (OSTI)

    Coleman, Joshua Eugene

    2008-05-23

    The Neutralized Drift Compression Experiment (NDCX) at Lawrence Berkeley National Laboratory is exploring the physical limits of compression and focusing of ion beams for heating material to warm dense matter (WDM) and fusion ignition conditions. The NDCX is a beam transport experiment with several components at a scale comparable to an inertial fusion energy driver. The NDCX is an accelerator which consists of a low-emittance ion source, high-current injector, solenoid matching section, induction bunching module, beam neutralization section, and final focusing system. The principal objectives of the experiment are to control the beam envelope, demonstrate effective neutralization of the beam space-charge, control the velocity tilt on the beam, and understand defocusing effects, field imperfections, and limitations on peak intensity such as emittance and aberrations. Target heating experiments with space-charge dominated ion beams require simultaneous longitudinal bunching and transverse focusing. A four-solenoid lattice is used to tune the beam envelope to the necessary focusing conditions before entering the induction bunching module. The induction bunching module provides a head-to-tail velocity ramp necessary to achieve peak axial compression at the desired focal plane. Downstream of the induction gap a plasma column neutralizes the beam space charge so only emittance limits the focused beam intensity. We present results of beam transport through a solenoid matching section and simultaneous focusing of a singly charged K{sup +} ion bunch at an ion energy of 0.3 MeV. The results include a qualitative comparison of experimental and calculated results after the solenoid matching section, which include time resolved current density, transverse distributions, and phase-space of the beam at different diagnostic planes. Electron cloud and gas measurements in the solenoid lattice and in the vicinity of intercepting diagnostics are also presented. Finally, comparisons of improved experimental and calculated axial focus (> 100 x axial compression, < 2 ns pulses) and higher peak energy deposition on target are also presented. These achievements demonstrate the capabilities for near term target heating experiments to T{sub e} {approx} 0.1 eV and for future ion accelerators to heat targets to T{sub e} > 1 eV.

  16. Particle beam generator using a radioactive source

    DOE Patents [OSTI]

    Underwood, D.G.

    1993-03-30

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  17. Physics with fast molecular-ion beams

    SciTech Connect (OSTI)

    Kanter, E.P.

    1980-01-01

    Fast (MeV) molecular-ion beams provide a unique source of energetic projectile nuclei which are correlated in space and time. The recognition of this property has prompted several recent investigations of various aspects of the interactions of these ions with matter. High-resolution measurements on the fragments resulting from these interactions have already yielded a wealth of new information on such diverse topics as plasma oscillations in solids and stereochemical structures of molecular ions as well as a variety of atomic collision phenomena. The general features of several such experiments will be discussed and recent results will be presented.

  18. Particle beam generator using a radioactive source

    DOE Patents [OSTI]

    Underwood, David G. (Naperville, IL)

    1993-01-01

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  19. Reflective echo tomographic imaging using acoustic beams

    DOE Patents [OSTI]

    Kisner, Roger; Santos-Villalobos, Hector J

    2014-11-25

    An inspection system includes a plurality of acoustic beamformers, where each of the plurality of acoustic beamformers including a plurality of acoustic transmitter elements. The system also includes at least one controller configured for causing each of the plurality of acoustic beamformers to generate an acoustic beam directed to a point in a volume of interest during a first time. Based on a reflected wave intensity detected at a plurality of acoustic receiver elements, an image of the volume of interest can be generated.

  20. Portable Parallel Beam X-Ray Diffraction System | Department of Energy

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

    Portable Parallel Beam X-Ray Diffraction System Portable Parallel Beam X-Ray Diffraction System New, Low Power System Reduces Energy Consumption and Improves Process Efficiency Real-time, nondestructive, in-line measurements of material properties are needed for process control in metallurgical manufacturing. With AMO support, X-Ray Optical Systems, Inc., developed the X-Beam®, a portable x-ray diffraction (XRD) system that can be used to identify structural phases, determine grain size, and

  1. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Van Winkle, D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; ,

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

  2. EXPERIMENTAL RESULTS FROM A MICROWAVE CAVITY BEAM POSITION MONITOR.

    SciTech Connect (OSTI)

    BALAKIN,V.; BAZHAN,A.; LUNEV,P.; SOLYAK,N.; VOGEL,V.; ZHOGOLEV,P.; LISITSYN,A.; YAKIMENKO,V.

    1999-03-29

    Future Linear Colliders have hard requirements for the beam transverse position stability in the accelerator. A beam Position Monitor (BPM) with the resolution better than 0.1 micron in the single bunch regime is needed to control the stability of the beam position along the linac. Proposed BPM is based on the measurement of the asymmetrical mode excited by single bunch in the cavity. Four stages of signal processing (space-, time-, frequency- and phase-filtering providing the required signal-to-noise ratio) are used to obtain extremely high resolution. The measurement set-up was designed by BINP and installed at ATF/BNL to test experimentally this concept. The set-up includes three two-coordinates BPM's at the frequency of 13.566 GHz, and reference intensity/phase cavity. BPM's were mounted on support table. The two-coordinates movers allow to move and align BPM's along the straight line, using the signals from the beam. The position of each monitor is controlled by the sensors with the accuracy 0.03 micron. The information from three monitors allows to exclude angle and position jitter of the beam and measure BPM resolution. In the experiments the resolution of about 0.15 micron for 0.25 nC beam intensity was obtained, that is close to the value required.

  3. Real time Faraday spectrometer

    DOE Patents [OSTI]

    Smith, Jr., Tommy E. (Fremont, CA); Struve, Kenneth W. (Albuquerque, NM); Colella, Nicholas J. (Livermore, CA)

    1991-01-01

    This invention uses a dipole magnet to bend the path of a charged particle beam. As the deflected particles exit the magnet, they are spatially dispersed in the bend-plane of the magnet according to their respective momenta and pass to a plurality of chambers having Faraday probes positioned therein. Both the current and energy distribution of the particles is then determined by the non-intersecting Faraday probes located along the chambers. The Faraday probes are magnetically isolated from each other by thin metal walls of the chambers, effectively providing real time current-versus-energy particle measurements.

  4. Overview of the APT high-energy beam transport and beam expanders

    SciTech Connect (OSTI)

    Shafer, R.E.; Blind, B.; Gray, E.R.

    1997-08-01

    The APT high energy beam transport (HEBT) and beam expanders convey the 1700-MeV, 100-mA cw proton beam from the linac to the tritium target/blanket assembly, or a tuning beam stop. The HEBT includes extensive beam diagnostics, collimators, and beam jitter correction, to monitor and control the 170-MW beam prior to expansion. A zero-degree beamline conveys the beam to the beam stop, and an achromatic bend conveys the beam to the tritium production target. Nonlinear beam expanders make use of higher-order multipole magnets and dithering dipoles to expand the beam to a uniform-density, 16-cm wide by 160-cm high rectangular profile on the tritium-production target. The overall optics design will be reviewed, and beam simulations will be presented.

  5. eRHIC ring-ring design with head-on beam-beam compensation

    SciTech Connect (OSTI)

    Montag,C.; Blaskiewicz, M.; Pozdeyev, E.; Fischer, W.; MacKay, W. W.

    2009-05-04

    The luminosity of the eRHIC ring-ring design is limited by the beam-beam effect exerted on the electron beam. Recent simulation studies have shown that the beam-beam limit can be increased by means of an electron lens that compensates the beam-beam effect experienced by the electron beam. This scheme requires proper design of the electron ring, providing the correct betatron phase advance between interaction point and electron lens. We review the performance of the eRHIC ring-ring version and discuss various parameter sets, based on different cooling schemes for the proton/ion beam.

  6. Multi-particle weak-strong simulation of RHIC head-on beam-beam compensation.

    SciTech Connect (OSTI)

    Luo,Y.; Abreu, N.; Beebe-Wang, J.; FischW; Robert-Demolaize, G.

    2008-06-23

    To compensate the large tune spread generated by the beam-beam interactions in the polarized proton (pp) run in the Relativistic Heavy Ion Collider (RHIC), a low energy round Gaussian electron beam or electron lens is proposed to collide head-on with the proton beam. Using a weakstrong beam-beam interaction model, we carry out multiparticle simulations to investigate the effects of head-on beam-beam compensation on the proton beam's lifetime and emittance growth. The simplectic 6-D element-by-element tracking code SixTrack is adopted and modified for this study. The code benchmarking and preliminary simulation results are presented.

  7. Studies of beam dynamics in relativistic klystron two-beam accelerators

    SciTech Connect (OSTI)

    Lidia, Steven M.

    1999-11-01

    Two-beam accelerators (TBAs) based upon free-electron lasers (FELs) or relativistic klystrons (RK-TBAs) have been proposed as efficient power sources for next generation high-energy linear colliders. Studies have demonstrated the possibility of building TBAs from X-band ({approximately}8-12 GHz) through Ka band ({approximately} 30-35 GHz) frequency regions. Provided that further prototyping shows stable beam propagation with minimal current loss and production of good quality, high-power rf fields, this technology is compatible with current schemes for electron-positron colliders in the multi-TeV center-of-mass scale. A new method of simulating the beam dynamics in accelerators of this type has been developed in this dissertation. There are three main components to this simulation. The first is a tracking algorithm to generate nonlinear transfer maps for pushing noninteracting particles through the external fields. The second component is a 3D Particle-In-Cell (PIC) algorithm that solves a set of Helmholtz equations for the self-fields, including the conducting boundary condition, and generates impulses that are interleaved with the nonlinear maps by means of a split-operation algorithm. The Helmholtz equations are solved by a multi-grid algorithm. The third component is an equivalent circuit equation solver that advances the modal rf cavity fields in time due to excitation by the modulated beam. The RTA project is described, and the simulation code is used to design the latter portions of the experiment. Detailed calculations of the beam dynamics and of the rf cavity output are presented and discussed. A beamline design is presented that will generate nearly 1.2 GW of power from 40 input, gain, and output rv cavities over a 10 m distance. The simulations show that beam current losses are acceptable, and that longitudinal and transverse focusing techniques are sufficient capable of maintaining a high degree of beam quality along the entire beamline. Additional experimental efforts are also described.

  8. Electron beam ion source and electron beam ion trap (invited)

    SciTech Connect (OSTI)

    Becker, Reinard [Scientific Software Service, Kapellenweg 2a, D-63571 Gelnhausen (Germany); Kester, Oliver [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States)

    2010-02-15

    The electron beam ion source (EBIS) and its trap variant [electron beam ion trap (EBIT)] celebrated their 40th and 20th anniversary, respectively, at the EBIS/T Symposium 2007 in Heidelberg. These technologically challenging sources of highly charged ions have seen a broad development in many countries over the last decades. In contrast to most other ion sources the recipe of improvement was not ''sorcery'' but a clear understanding of the physical laws and obeying the technological constraints. This review will report important achievements of the past as well as promising developments in the future.

  9. Development of two-beam femtosecond/picosecond one-dimensional rotational

    Office of Scientific and Technical Information (OSTI)

    coherent anti-Stokes Raman spectroscopy: time-resolved probing of flame wall interactions. (Conference) | SciTech Connect Development of two-beam femtosecond/picosecond one-dimensional rotational coherent anti-Stokes Raman spectroscopy: time-resolved probing of flame wall interactions. Citation Details In-Document Search Title: Development of two-beam femtosecond/picosecond one-dimensional rotational coherent anti-Stokes Raman spectroscopy: time-resolved probing of flame wall interactions.

  10. Precision timing measurements for high energy photons

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

    Anderson, Dustin; Apreysan, Artur; Bornheim, Adi; Duarte, Javier; Newman, Harvey; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Trevor, Jason; Xie, Si; et al

    2014-11-21

    Particle colliders operating at high luminosities present challenging environments for high energy physics event reconstruction and analysis. We discuss how timing information, with a precision on the order of 10 ps, can aid in the reconstruction of physics events under such conditions. We present calorimeter based timing measurements from test beam experiments in which we explore the ultimate timing precision achievable for high energy photons or electrons of 10 GeV and above. Using a prototype calorimeter consisting of a 1.71.71.7 cm3 lutetiumyttrium oxyortho-silicate (LYSO) crystal cube, read out by micro-channel plate photomultipliers, we demonstrate a time resolution of 33.52.1 psmorefor an incoming beam energy of 32 GeV. In a second measurement, using a 2.52.520 cm3 LYSO crystal placed perpendicularly to the electron beam, we achieve a time resolution of 5911 ps using a beam energy of 4 GeV. We also present timing measurements made using a shashlik-style calorimeter cell made of LYSO and tungsten plates, and demonstrate that the apparatus achieves a time resolution of 545 ps for an incoming beam energy of 32 GeV.less

  11. Preliminary result of rapid solenoid for controlling heavy-ion beam parameters of laser ion source

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

    Okamura, M.; Sekine, M.; Ikeda, S.; Kanesue, T.; Kumaki, M.; Fuwa, Y.

    2015-03-13

    To realize a heavy ion inertial fusion driver, we have studied a possibility of laser ion source (LIS). A LIS can provide high current high brightness heavy ion beams, however it was difficult to manipulate the beam parameters. To overcome the issue, we employed a pulsed solenoid in the plasma drift section and investigated the effect of the solenoid field on singly charged iron beams. The rapid ramping magnetic field could enhance limited time slice of the current and simultaneously the beam emittance changed accordingly. This approach may also useful to realize an ion source for HIF power plant.

  12. Beam-energy and laser beam-profile monitor at the BNL LINAC

    SciTech Connect (OSTI)

    Connolly, R.; Briscoe, B.; Degen, C.; DeSanto, L.; Meng, W.; Minty, M.; Nayak, S.; Raparia, D.; Russo, T.

    2010-05-02

    We are developing a non-interceptive beam profile and energy monitor for H{sup -} beams in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. Electrons that are removed from the beam ions either by laser photodetachment or stripping by background gas are deflected into a Faraday cup. The beam profile is measured by stepping a narrow laser beam across the ion beam and measuring the electron charge vs. transverse laser position. There is a grid in front of the collector that can be biased up to 125kV. The beam energy spectrum is determined by measuring the electron charge vs. grid voltage. Beam electrons have the same velocity as the beam and so have an energy of 1/1836 of the beam protons. A 200MeV H{sup -} beam yields 109keV electrons. Energy measurements can be made with either laser-stripped or gas-stripped electrons.

  13. Quantized beam shifts in graphene

    SciTech Connect (OSTI)

    de Melo Kort-Kamp, Wilton Junior; Sinitsyn, Nikolai; Dalvit, Diego Alejandro Roberto

    2015-10-08

    We predict the existence of quantized Imbert-Fedorov, Goos-Hanchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant ?, while the Goos-Hanchen ones in multiples of ?2. We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

  14. Dye laser amplifier including an improved window configuration for its dye beam

    DOE Patents [OSTI]

    O'Neil, R.W.; Davin, J.M.

    1992-12-01

    A dye laser amplifier in which a continuously replenished supply of dye is excited with a first light beam in order to amplify the intensity of a second different light beam passing therethrough is disclosed herein. This amplifier includes a cell though which a continuous stream of the dye is caused to pass, and means for directing the first beam into the cell while the second beam is directed into and through the same cell. There is also disclosed herein a specific improvement to this amplifier which resides in the use of a pair of particularly configured windows through which the second beam passes along fixed paths as the second beam enters and exits the dye cell. Each of these windows has a relatively thick main section which is substantially larger in dimensions transverse to its beam path than the cross section of the second beam itself, whereby to add structural integrity to the overall window. At the same time, the latter includes a second section which is disposed entirely within the confines of the main section and through which the second beam is intended to pass in its entirety. This second section is made substantially thinner than the main section in order to reduce optical distortion as the second beam passes therethrough. 4 figs.

  15. Dye laser amplifier including an improved window configuration for its dye beam

    DOE Patents [OSTI]

    O'Neil, Richard W. (Pleasanton, CA); Davin, James M. (Livermore, CA)

    1992-01-01

    A dye laser amplifier in which a continuously replenished supply of dye is excited with a first light beam in order to amplify the intensity of a second different light beam passing therethrough is disclosed herein. This amplifier includes a cell though which a continuous stream of the dye is caused to pass, and means for directing the first beam into the cell while the second beam is directed into and through the same cell. There is also disclosed herein a specific improvement to this amplifier which resides in the use of a pair of particularly configured windows through which the second beam passes along fixed paths as the second beam enters and exits the dye cell. Each of these windows has a relatively thick main section which is substantially larger in dimensions transverse to its beam path than the cross section of the second beam itself, whereby to add structural integrity to the overall window. At the same time, the latter includes a second section which is disposed entirely within the confines of the main section and through which the second beam is intended to pass in its entirety. This second section is made substantially thinner than the main section in order to reduce optical distortion as the second beam passes therethrough.

  16. Particle-in-cell simulations of electron beam control using an inductive current divider

    SciTech Connect (OSTI)

    Swanekamp, S. B.; Angus, J. R.; Cooperstein, G.; Ottinger, P. F.; Richardson, A. S.; Schumer, J. W.; Weber, B. V.

    2015-11-18

    Kinetic, time-dependent, electromagnetic, particle-in-cell simulations of the inductive current divider are presented. The inductive current divider is a passive method for controlling the trajectory of an intense, hollow electron beam using a vacuum structure that inductively splits the beams return current. The current divider concept was proposed and studied theoretically in a previous publication [Phys. Plasmas 22, 023107 (2015)] A central post carries a portion of the return current (I1) while the outer conductor carries the remainder (I2) with the injected beam current given by Ib=I1+I2. The simulations are in agreement with the theory which predicts that the total force on the beam trajectory is proportional to (I2-I1) and the force on the beam envelope is proportional to Ib. For a fixed central post, the beam trajectory is controlled by varying the outer conductor radius which changes the inductance in the return-current path. The simulations show that the beam emittance is approximately constant as the beam propagates through the current divider to the target. As a result, independent control over both the current density and the beam angle at the target is possible by choosing the appropriate return-current geometry.

  17. Characterization and use of the spent beam for serial operation of LCLS

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

    Boutet, Sébastien; Foucar, Lutz; Barends, Thomas R. M.; Botha, Sabine; Doak, R. Bruce; Koglin, Jason E.; Messerschmidt, Marc; Nass, Karol; Schlichting, Ilme; Seibert, M. Marvin; et al

    2015-04-11

    X-ray free-electron laser sources such as the Linac Coherent Light Source offer very exciting possibilities for unique research. However, beam time at such facilities is very limited and in high demand. This has led to significant efforts towards beam multiplexing of various forms. One such effort involves re-using the so-called spent beam that passes through the hole in an area detector after a weak interaction with a primary sample. This beam can be refocused into a secondary interaction region and used for a second, independent experiment operating in series. The beam profile of this refocused beam was characterized for amore » particular experimental geometry at the Coherent X-ray Imaging instrument at LCLS. A demonstration of this multiplexing capability was performed with two simultaneous serial femtosecond crystallography experiments, both yielding interpretable data of sufficient quality to produce electron density maps.« less

  18. Characterization and use of the spent beam for serial operation of LCLS

    SciTech Connect (OSTI)

    Boutet, Sbastien; Foucar, Lutz; Barends, Thomas R. M.; Botha, Sabine; Doak, R. Bruce; Koglin, Jason E.; Messerschmidt, Marc; Nass, Karol; Schlichting, Ilme; Seibert, M. Marvin; Shoeman, Robert L.; Williams, Garth J.

    2015-04-11

    X-ray free-electron laser sources such as the Linac Coherent Light Source offer very exciting possibilities for unique research. However, beam time at such facilities is very limited and in high demand. This has led to significant efforts towards beam multiplexing of various forms. One such effort involves re-using the so-called spent beam that passes through the hole in an area detector after a weak interaction with a primary sample. This beam can be refocused into a secondary interaction region and used for a second, independent experiment operating in series. The beam profile of this refocused beam was characterized for a particular experimental geometry at the Coherent X-ray Imaging instrument at LCLS. A demonstration of this multiplexing capability was performed with two simultaneous serial femtosecond crystallography experiments, both yielding interpretable data of sufficient quality to produce electron density maps.

  19. Simulations of Head-On Beam-Beam Compensation at RHIC and LHC

    SciTech Connect (OSTI)

    Valishev, A.; /Fermilab

    2010-05-19

    Electron lenses are proposed as a way to mitigate head-on beam-beam effects for RHIC and LHC upgrades. An extensive effort was put together within the US LARP in order to develop numerical simulations of beam-beam effects in the presence of electron lenses. In this report the results of numerical beam-beam simulations for RHIC and LHC are presented. The effect of electron lenses is demonstrated and sensitivity of beam-beam compensation to machine parameters is discussed.

  20. Mechanical beam isolator for high-power laser systems

    DOE Patents [OSTI]

    Post, Richard F. (Walnut Creek, CA); Vann, Charles S. (Fremont, CA)

    1998-01-01

    A mechanical beam isolator uses rod-shaped elements having a Gaussian configuration to interrupt the path of a beam of photons or particles when the time-scale of the needed interruption is of the order of a microsecond or less. One or more of these rods is mounted transversely to, and penetrates through, a rotating shaft supported by bearings. Owing to the Gaussian geometry of the rods, they are able to withstand much higher rotation speeds, without tensile failure, than rods having any other geometrical shape.

  1. Mechanical beam isolator for high-power laser systems

    DOE Patents [OSTI]

    Post, R.F.; Vann, C.S.

    1998-07-07

    A mechanical beam isolator uses rod-shaped elements having a Gaussian configuration to interrupt the path of a beam of photons or particles when the time-scale of the needed interruption is of the order of a microsecond or less. One or more of these rods is mounted transversely to, and penetrates through, a rotating shaft supported by bearings. Owing to the Gaussian geometry of the rods, they are able to withstand much higher rotation speeds, without tensile failure, than rods having any other geometrical shape. 3 figs.

  2. Interactive visualization of particle beams for accelerator design

    SciTech Connect (OSTI)

    Wilson, Brett; Ma, Kwan-Liu; Qiang, Ji; Ryne, Robert

    2002-01-15

    We describe a hybrid data-representation and rendering technique for visualizing large-scale particle data generated from numerical modeling of beam dynamics. The basis of the technique is mixing volume rendering and point rendering according to particle density distribution, visibility, and the user's instruction. A hierarchical representation of the data is created on a parallel computer, allowing real-time partitioning into high-density areas for volume rendering, and low-density areas for point rendering. This allows the beam to be interactively visualized while preserving the fine structure usually visible only with slow point based rendering techniques.

  3. Thermoacoustic imaging using heavy ion beams

    SciTech Connect (OSTI)

    Claytor, T.N.; Tesmer, J.R.; Deemer, B.C.; Murphy, J.C.

    1995-10-01

    Ion beams have been used for surface modification, semiconductor device fabrication and for material analysis, which makes ion-material interactions of significant importance. Ion implantation will produce new compositions near the surface by ion mixing or directly by implanting desired ions. Ions exchange their energy to the host material as they travel into the material by several different processes. High energy ions ionize the host atoms before atomic collisions transfer the remaining momentum and stop the incident ion. As they penetrate the surface, the low energy ions ionize the host atoms, but also have a significantly large momentum transfer mechanism near the surface of the material. This leads to atoms, groups of atoms and electrons being ejected from the surface, which is the momentum transfer process of sputtering. This talk addresses the acoustic waves generated during ion implantation using modulated heavy ion beams. The mechanisms for elastic wave generation during ion implantation, in the regimes where sputtering is significant and where implantation is dominant and sputtering is negligible, has been studied. The role of momentum transfer and thermal energy production during ion implantation was compared to laser generated elastic waves in an opaque solid as a reference, since laser generated ultrasound has been extensively studied and is fairly well understood. The thermoelastic response dominated in both high and low ion energy regimes since, apparently, more energy is lost to thermal heat producing mechanisms than momentum transfer processes. The signal magnitude was found to vary almost linearly with incident energy as in the laser thermoelastic regime. The time delays for longitudinal and shear waves-were characteristic of those expected for a purely thermal heating source. The ion beams are intrinsically less sensitive to the albedo of the surface.

  4. SPEAR3 Beam Line Availability

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

    and Wide Angle X-ray Scattering Open 1-5 MC MAD, Monochromatic Open 2-1 X-ray Powder Diffraction Open 2-2 X-ray Michromachining, Topography, White Beam, LIGA Down 2-3 X-ray XAS,...

  5. Bunch length effects in the beam-beam compensation with an electron lens

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Montag, C.

    2010-02-25

    Electron lenses for the head-on beam-beam compensation are under construction at the Relativistic Heavy Ion Collider. The bunch length is of the same order as the {beta}-function at the interaction point, and a proton passing through another proton bunch experiences a substantial phase shift which modifies the beam-beam interaction. We review the effect of the bunch length in the single pass beam-beam interaction, apply the same analysis to a proton passing through a long electron lens, and study the single pass beam-beam compensation with long bunches. We also discuss the beam-beam compensation of the electron beam in an electron-ion collider ring.

  6. Time Off

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

    Time Off Time Off A comprehensive benefits package with plan options for health care and retirement to take care of our employees today and tomorrow. Contact Benefits Office (505)...

  7. Kinematic evidence for precessing beams in 3C 129

    SciTech Connect (OSTI)

    Icke, V.

    1981-06-01

    Some features of the radio trail of 3C 129 can be explained if it is assumed that the trail is due to plasma beams which precess as the galaxy traverses the intergalactic medium. The solution of a simple equation of motion, incorporating ram pressure in an external medium, is fitted to the trail. It is shown that the observations can be reproduced, to first order, if the beam generator in the galactic nucleus precesses with a period of 9 x 10/sup 6/ yr on a cone with opening half-angle 12/sup 0/, if the ram pressure stopping time scale is 5 x 10/sup 6/ yr, and if the initial speed of the plasma beam is 2600 km s/sup -1/.

  8. Enhancing Neutron Beam Production with a Convoluted Moderator

    SciTech Connect (OSTI)

    Iverson, Erik B; Baxter, David V; Muhrer, Guenter; Ansell, Stuart; Gallmeier, Franz X; Dalgliesh, Robert; Lu, Wei; Kaiser, Helmut

    2014-10-01

    We describe a new concept for a neutron moderating assembly resulting in the more efficient production of slow neutron beams. The Convoluted Moderator, a heterogeneous stack of interleaved moderating material and nearly transparent single-crystal spacers, is a directionally-enhanced neutron beam source, improving beam effectiveness over an angular range comparable to the range accepted by neutron beam lines and guides. We have demonstrated gains of 50% in slow neutron intensity for a given fast neutron production rate while simultaneously reducing the wavelength-dependent emission time dispersion by 25%, both coming from a geometric effect in which the neutron beam lines view a large surface area of moderating material in a relatively small volume. Additionally, we have confirmed a Bragg-enhancement effect arising from coherent scattering within the single-crystal spacers. We have not observed hypothesized refractive effects leading to additional gains at long wavelength. In addition to confirmation of the validity of the Convoluted Moderator concept, our measurements provide a series of benchmark experiments suitable for developing simulation and analysis techniques for practical optimization and eventual implementation at slow neutron source facilities.

  9. A Case Study in Proton Pencil-Beam Scanning Delivery

    SciTech Connect (OSTI)

    Kooy, Hanne M.; Clasie, Benjamin M.; Lu, H.-M.; Madden, Thomas M.; Bentefour, Hassan; Depauw, Nicolas M.S.; Adams, Judy A.; Trofimov, Alexei V.; Demaret, Denis; Delaney, Thomas F.; Flanz, Jacob B.

    2010-02-01

    Purpose: We completed an implementation of pencil-beam scanning (PBS), a technology whereby a focused beam of protons, of variable intensity and energy, is scanned over a plane perpendicular to the beam axis and in depth. The aim of radiotherapy is to improve the target to healthy tissue dose differential. We illustrate how PBS achieves this aim in a patient with a bulky tumor. Methods and Materials: Our first deployment of PBS uses 'broad' pencil-beams ranging from 20 to 35 mm (full-width-half-maximum) over the range interval from 32 to 7 g/cm{sup 2}. Such beam-brushes offer a unique opportunity for treating bulky tumors. We present a case study of a large (4,295 cc clinical target volume) retroperitoneal sarcoma treated to 50.4 Gy relative biological effectiveness (RBE) (presurgery) using a course of photons and protons to the clinical target volume and a course of protons to the gross target volume. Results: We describe our system and present the dosimetry for all courses and provide an interdosimetric comparison. Discussion: The use of PBS for bulky targets reduces the complexity of treatment planning and delivery compared with collimated proton fields. In addition, PBS obviates, especially for cases as presented here, the significant cost incurred in the construction of field-specific hardware. PBS offers improved dose distributions, reduced treatment time, and reduced cost of treatment.

  10. Collimation Studies with Hollow Electron Beams

    SciTech Connect (OSTI)

    Stancari, G.; Annala, G.; Johnson, T.R.; Saewert, G.W.; Shiltsev, V.; Still, D.A.; Valishev, A.; /Fermilab

    2011-08-01

    Recent experimental studies at the Fermilab Tevatron collider have shown that magnetically confined hollow electron beams can act as a new kind of collimator for high-intensity beams in storage rings. In a hollow electron beam collimator, electrons enclose the circulating beam. Their electric charge kicks halo particles transversely. If their distribution is axially symmetric, the beam core is unaffected. This device is complementary to conventional two-stage collimation systems: the electron beam can be placed arbitrarily close to the circulating beam; and particle removal is smooth, so that the device is a diffusion enhancer rather than a hard aperture limitation. The concept was tested in the Tevatron collider using a hollow electron gun installed in one of the existing electron lenses. We describe some of the technical aspects of hollow-beam scraping and the results of recent measurements.

  11. Property:Beam(m) | Open Energy Information

    Open Energy Info (EERE)

    Beam(m) Jump to: navigation, search This is a property of type String. Pages using the property "Beam(m)" Showing 25 pages using this property. (previous 25) (next 25) 1 1.5-ft...

  12. Neutral particle beam sensing and steering

    DOE Patents [OSTI]

    Maier, II, William B. (Los Alamos, NM); Cobb, Donald D. (Los Alamos, NM); Robiscoe, Richard T. (Los Alamos, NM)

    1991-01-01

    The direction of a neutral particle beam (NPB) is determined by detecting Ly.alpha. radiation emitted during motional quenching of excited H(2S) atoms in the beam during movement of the atoms through a magnetic field. At least one detector is placed adjacent the beam exit to define an optical axis that intercepts the beam at a viewing angle to include a volume generating a selected number of photons for detection. The detection system includes a lens having an area that is small relative to the NPB area and a pixel array located in the focal plane of the lens. The lens viewing angle and area pixel array are selected to optimize the beam tilt sensitivity. In one embodiment, two detectors are placed coplanar with the beam axis to generate a difference signal that is insensitive to beam variations other than beam tilt.

  13. 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.

  14. Maskless, resistless ion beam lithography

    SciTech Connect (OSTI)

    Ji, Qing

    2003-03-10

    As the dimensions of semiconductor devices are scaled down, in order to achieve higher levels of integration, optical lithography will no longer be sufficient for the needs of the semiconductor industry. Alternative next-generation lithography (NGL) approaches, such as extreme ultra-violet (EUV), X-ray, electron-beam, and ion projection lithography face some challenging issues with complicated mask technology and low throughput. Among the four major alternative NGL approaches, ion beam lithography is the only one that can provide both maskless and resistless patterning. As such, it can potentially make nano-fabrication much simpler. This thesis investigates a focused ion beam system for maskless, resistless patterning that can be made practical for high-volume production. In order to achieve maskless, resistless patterning, the ion source must be able to produce a variety of ion species. The compact FIB system being developed uses a multicusp plasma ion source, which can generate ion beams of various elements, such as O{sub 2}{sup +}, BF{sub 2}{sup +}, P{sup +} etc., for surface modification and doping applications. With optimized source condition, around 85% of BF{sub 2}{sup +}, over 90% of O{sub 2}{sup +} and P{sup +} have been achieved. The brightness of the multicusp-plasma ion source is a key issue for its application to maskless ion beam lithography. It can be substantially improved by optimizing the source configuration and extractor geometry. Measured brightness of 2 keV He{sup +} beam is as high as 440 A/cm{sup 2} {center_dot} Sr, which represents a 30x improvement over prior work. Direct patterning of Si thin film using a focused O{sub 2}{sup +} ion beam has been investigated. A thin surface oxide film can be selectively formed using 3 keV O{sub 2}{sup +} ions with the dose of 10{sup 15} cm{sup -2}. The oxide can then serve as a hard mask for patterning of the Si film. The process flow and the experimental results for directly patterned poly-Si features are presented. The formation of shallow pn-junctions in bulk silicon wafers by scanning focused P{sup +} beam implantation at 5 keV is also presented. With implantation dose of around 10{sup 16} cm{sup -2}, the electron concentration is about 2.5 x 10{sup 18} cm{sup -3} and electron mobility is around 200 cm{sup 2}/V{center_dot}s. To demonstrate the suitability of scanning FIB lithography for the manufacture of integrated circuit devices, SOI MOSFET fabrication using the maskless, resistless ion beam lithography is demonstrated. An array of microcolumns can be built by stacking multi-aperture electrode and insulator layers. Because the multicusp plasma source can achieve uniform ion density over a large area, it can be used in conjunction with the array of microcolumns, for massively parallel FIB processing to achieve reasonable exposure throughput.

  15. Beam instability studies for the SSC

    SciTech Connect (OSTI)

    Chou, W.

    1994-09-01

    Beam instability studies of the Superconducting Super Collider (SSC) during the period 1989--1993 are briefly reviewed in this paper. Various topics are covered: single bunch and multi-bunch, single beam and beam-beam, parasitic heating and active feedback, etc. Although the SSC will not be built, many of the results obtained from these studies remain as useful references to the accelerator community.

  16. The NuMI Neutrino Beam

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

    Adamson, P.; Anderson, K.; Andrews, M.; Andrews, R.; Anghel, I.; Augustine, D.; Aurisano, A.; Avvakumov, S.; Ayres, D. S.; Baller, B.; et al

    2015-10-20

    Our paper describes the hardware and operations of the Neutrinos at the Main Injector (NuMI) beam at Fermilab. It elaborates on the design considerations for the beam as a whole and for individual elements. The most important part of our design details pertaining to individual components is described. Beam monitoring systems and procedures, including the tuning and alignment of the beam and NuMI long-term performance, are also discussed.

  17. Beam On Target! - CEBAF Accelerator Achieves 12 GeV Commissioning...

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

    in an experimental hall, recording the first data of the 12 GeV era. The machine sent electrons around the racetrack three times (known as "3-pass" beam), resulting in 6.11 GeV...

  18. A new luminescence beam profile monitor for intense proton and heavy ion beams

    SciTech Connect (OSTI)

    Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

    2008-10-01

    A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

  19. Control of post-disruption runaway electron beams in DIII-D

    SciTech Connect (OSTI)

    Eidietis, N. W.; Humphreys, D. A.; Strait, E. J.; VanZeeland, M. A.; Wesley, J. C.; Commaux, N.; Jernigan, T. C.; Hollmann, E. M.; Moyer, R. A.; Yu, J. H.

    2012-05-15

    Recent experiments in the DIII-D tokamak have demonstrated real-time control and dissipation of post-disruption runaway electron (RE) beams. In the event that disruption avoidance, control, and mitigation schemes fail to avoid or suppress RE generation, active control of the RE beam may be an important line of defense to prevent the rapid, localized deposition of RE beam energy onto vulnerable vessel sections. During and immediately after the current quench, excessive radial compression of the runaway beams is avoided by a combination of techniques, improving the likelihood of the beams surviving this dynamic period without a fast termination. Once stabilized, the runaway beams are held in a steady state (out to the ohmic flux limit) with the application of active plasma current and position controls. Beam interaction with the vessel wall is minimized by avoiding distinct thresholds for enhanced wall interaction at small and large radii, corresponding to inner wall and outer limiter interaction, respectively. Staying within the 'safe zone' between those radial thresholds allows for the sustainment of long-lived, quiescent runaway beams. The total beam energy and runaway electron population are then dissipated gradually by a controlled ramp-down of the runaway current.

  20. Beam shuttering interferometer and method

    DOE Patents [OSTI]

    Deason, Vance A. (Idaho Falls, ID); Lassahn, Gordon D. (Idaho Falls, ID)

    1993-01-01

    A method and apparatus resulting in the simplification of phase shifting interferometry by eliminating the requirement to know the phase shift between interferograms or to keep the phase shift between interferograms constant. The present invention provides a simple, inexpensive means to shutter each independent beam of the interferometer in order to facilitate the data acquisition requirements for optical interferometry and phase shifting interferometry. By eliminating the requirement to know the phase shift between interferograms or to keep the phase shift constant, a simple, economical means and apparatus for performing the technique of phase shifting interferometry is provide which, by thermally expanding a fiber optical cable changes the optical path distance of one incident beam relative to another.

  1. Beam shuttering interferometer and method

    DOE Patents [OSTI]

    Deason, V.A.; Lassahn, G.D.

    1993-07-27

    A method and apparatus resulting in the simplification of phase shifting interferometry by eliminating the requirement to know the phase shift between interferograms or to keep the phase shift between interferograms constant. The present invention provides a simple, inexpensive means to shutter each independent beam of the interferometer in order to facilitate the data acquisition requirements for optical interferometry and phase shifting interferometry. By eliminating the requirement to know the phase shift between interferograms or to keep the phase shift constant, a simple, economical means and apparatus for performing the technique of phase shifting interferometry is provide which, by thermally expanding a fiber optical cable changes the optical path distance of one incident beam relative to another.

  2. Beam collimation at hadron colliders

    SciTech Connect (OSTI)

    Nikolai V. Mokhov

    2003-08-12

    Operational and accidental beam losses in hadron colliders can have a serious impact on machine and detector performance, resulting in effects ranging from minor to catastrophic. Principles and realization are described for a reliable beam collimation system required to sustain favorable background conditions in the collider detectors, provide quench stability of superconducting magnets, minimize irradiation of accelerator equipment, maintain operational reliability over the life of the machine, and reduce the impact of radiation on personnel and the environment. Based on detailed Monte-Carlo simulations, such a system has been designed and incorporated in the Tevatron collider. Its performance, comparison to measurements and possible ways to further improve the collimation efficiency are described in detail. Specifics of the collimation systems designed for the SSC, LHC, VLHC, and HERA colliders are discussed.

  3. Oxygen ion-beam microlithography

    DOE Patents [OSTI]

    Tsuo, Y.S.

    1991-08-20

    A method of providing and developing a resist on a substrate for constructing integrated circuit (IC) chips includes the following steps: of depositing a thin film of amorphous silicon or hydrogenated amorphous silicon on the substrate and exposing portions of the amorphous silicon to low-energy oxygen ion beams to oxidize the amorphous silicon at those selected portions. The nonoxidized portions are then removed by etching with RF-excited hydrogen plasma. Components of the IC chip can then be constructed through the removed portions of the resist. The entire process can be performed in an in-line vacuum production system having several vacuum chambers. Nitrogen or carbon ion beams can also be used. 5 figures.

  4. X-ray beam finder

    DOE Patents [OSTI]

    Gilbert, H.W.

    1983-06-16

    An X-ray beam finder for locating a focal spot of an X-ray tube includes a mass of X-ray opaque material having first and second axially-aligned, parallel-opposed faces connected by a plurality of substantially identical parallel holes perpendicular to the faces and a film holder for holding X-ray sensitive film tightly against one face while the other face is placed in contact with the window of an X-ray head.

  5. Ion beam inertial confinement target

    DOE Patents [OSTI]

    Bangerter, Roger O. (Danville, CA); Meeker, Donald J. (Livermore, CA)

    1985-01-01

    A target for implosion by ion beams composed of a spherical shell of frozen DT surrounded by a low-density, low-Z pusher shell seeded with high-Z material, and a high-density tamper shell. The target has various applications in the inertial confinement technology. For certain applications, if desired, a low-density absorber shell may be positioned intermediate the pusher and tamper shells.

  6. Time delay spectrum conditioner

    DOE Patents [OSTI]

    Greiner, Norman R. (Los Alamos, NM)

    1980-01-01

    A device for delaying specified frequencies of a multiple frequency laser beam. The device separates the multiple frequency beam into a series of spatially separated single frequency beams. The propagation distance of the single frequency beam is subsequently altered to provide the desired delay for each specific frequency. Focusing reflectors can be utilized to provide a simple but nonadjustable system or, flat reflectors with collimating and focusing optics can be utilized to provide an adjustable system.

  7. Stability of Single Particle Motion with Head-On Beam-Beam Compensation in the RHIC

    SciTech Connect (OSTI)

    Luo,Y.; Fischer, W.; Abreu, N.

    2008-05-01

    To compensate the large tune shift and tune spread generated by the head-on beam-beam interactions in the polarized proton run in the Relativistic Heavy Ion Collider (RHIC), we proposed a low energy electron beam with a Gaussian transverse profiles to collide head-on with the proton beam. In this article, with a weak-strong beam-beam interaction model, we investigate the stability of single particle motion in the presence of head-on beam-beam compensation. Tune footprints, tune diffusion, Lyapunov exponents, and 10{sup 6} turn dynamic apertures are calculated and compared between the cases without and with beam-beam compensation. A tune scan is performed and the possibility of increasing the bunch intensity is studied. The cause of tune footprint foldings is discussed, and the tune diffusion and Lyapunov exponent analysis are compared.

  8. Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators

    SciTech Connect (OSTI)

    Mastoridis, Themistoklis; /Stanford U., Elect. Eng. Dept. /SLAC

    2011-03-01

    The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC. Simulations studies and measurements were conducted that clearly show the correlation between RF noise and longitudinal bunch emittance, identify the major LLRF noise contributions, and determine the RF component dominating this effect. With these results, LHC upgrades and alternative algorithms are evaluated to reduce longitudinal emittance growth during operations. The applications of this work are described with regard to future machines and analysis of new technical implementations, as well as to possible future work which would continue the directions of this dissertation.

  9. Scattering apodizer for laser beams

    DOE Patents [OSTI]

    Summers, M.A.; Hagen, W.F.; Boyd, R.D.

    1984-01-01

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  10. Scattering apodizer for laser beams

    DOE Patents [OSTI]

    Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)

    1985-01-01

    A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

  11. W-Band Sheet Beam Klystron Design

    SciTech Connect (OSTI)

    Scheitrum, G.; Caryotakis, G.; Burke, A.; Jensen, A.; Jongewaard, E.a Krasnykh, A.; Neubauer, M.; Phillips, R.; Rauenbuehler, K.; /SLAC

    2011-11-11

    Sheet beam devices provide important advantages for very high power, narrow bandwidth RF sources like accelerator klystrons [1]. Reduced current density and increased surface area result in increased power capabi1ity, reduced magnetic fields for focusing and reduced cathode loading. These advantages are offset by increased complexity, beam formation and transport issues and potential for mode competition in the ovennoded cavities and drift tube. This paper will describe the design issues encountered in developing a 100 kW peak and 2 kW average power sheet beam k1ystron at W-band including beam formation, beam transport, circuit design, circuit fabrication and mode competition.

  12. Electron beam generation in Tevatron electron lenses

    SciTech Connect (OSTI)

    Kamerdzhiev, V.; Kuznetsov, G.; Shiltsev, V.; Solyak, N.; Tiunov, M.; /Novosibirsk, IYF

    2006-08-01

    New type of high perveance electron guns with convex cathode has been developed. Three guns described in this article are built to provide transverse electron current density distributions needed for Electron Lenses for beam-beam compensation in the Tevatron collider. The current distribution can be controlled either by the gun geometry or by voltage on a special control electrode located near cathode. We present the designs of the guns and report results of beam measurements on the test bench. Because of their high current density and low transverse temperature of electrons, electron guns of this type can be used in electron cooling and beam-beam compensation devices.

  13. Optimizing the beam-beam alignment in an electron lens using bremsstrahlung

    SciTech Connect (OSTI)

    Montag, C.; Fischer, W.; Gassner, D.; Thieberger, P.; Haug, E.

    2010-05-23

    Installation of electron lenses for the purpose of head-on beam-beam compensation is foreseen at RHIC. To optimize the relative alignment of the electron lens beam with the circulating proton (or ion) beam, photon detectors will be installed to measure the bremsstrahlung generated by momentum transfer from protons to electrons. We present the detector layout and simulations of the bremsstrahlung signal as function of beam offset and crossing angle.

  14. SU-E-T-50: Automatic Validation of Megavoltage Beams Modeled for Clinical Use in Radiation Therapy

    SciTech Connect (OSTI)

    Melchior, M; Salinas Aranda, F; Sciutto, S; Dodat, D; Larragueta, N

    2014-06-01

    Purpose: To automatically validate megavoltage beams modeled in XiO 4.50 (Elekta, Stockholm, Sweden) and Varian Eclipse Treatment Planning Systems (TPS) (Varian Associates, Palo Alto, CA, USA), reducing validation time before beam-on for clinical use. Methods: A software application that can automatically read and analyze DICOM RT Dose and W2CAD files was developed using MatLab integrated development environment.TPS calculated dose distributions, in DICOM RT Dose format, and dose values measured in different Varian Clinac beams, in W2CAD format, were compared. Experimental beam data used were those acquired for beam commissioning, collected on a water phantom with a 2D automatic beam scanning system.Two methods were chosen to evaluate dose distributions fitting: gamma analysis and point tests described in Appendix E of IAEA TECDOC-1583. Depth dose curves and beam profiles were evaluated for both open and wedged beams. Tolerance parameters chosen for gamma analysis are 3% and 3 mm dose and distance, respectively.Absolute dose was measured independently at points proposed in Appendix E of TECDOC-1583 to validate software results. Results: TPS calculated depth dose distributions agree with measured beam data under fixed precision values at all depths analyzed. Measured beam dose profiles match TPS calculated doses with high accuracy in both open and wedged beams. Depth and profile dose distributions fitting analysis show gamma values < 1. Relative errors at points proposed in Appendix E of TECDOC-1583 meet therein recommended tolerances.Independent absolute dose measurements at points proposed in Appendix E of TECDOC-1583 confirm software results. Conclusion: Automatic validation of megavoltage beams modeled for their use in the clinic was accomplished. The software tool developed proved efficient, giving users a convenient and reliable environment to decide whether to accept or not a beam model for clinical use. Validation time before beam-on for clinical use was reduced to a few hours.

  15. Generation of low-divergence laser beams

    DOE Patents [OSTI]

    Kronberg, J.W.

    1993-09-14

    Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source. 11 figures.

  16. Generation of low-divergence laser beams

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1993-01-01

    Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.

  17. Particle beam injector system and method

    DOE Patents [OSTI]

    Guethlein, Gary

    2013-06-18

    Methods and devices enable coupling of a charged particle beam to a radio frequency quadrupole accelerator. Coupling of the charged particle beam is accomplished, at least in-part, by relying on of sensitivity of the input phase space acceptance of the radio frequency quadrupole to the angle of the input charged particle beam. A first electric field across a beam deflector deflects the particle beam at an angle that is beyond the acceptance angle of the radio frequency quadrupole. By momentarily reversing or reducing the established electric field, a narrow portion of the charged particle beam is deflected at an angle within the acceptance angle of the radio frequency quadrupole. In another configuration, beam is directed at an angle within the acceptance angle of the radio frequency quadrupole by the first electric field and is deflected beyond the acceptance angle of the radio frequency quadrupole due to the second electric field.

  18. 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.; Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766; Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755

    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 results show there is good potential for real-time superficial dose monitoring. Dose imaging under normal ambient room lighting was validated, using gated detection and a breast phantom.Conclusions: This study indicates that Čerenkov emission imaging might provide a valuable way to superficial dosimetry imaging in real time for external beam radiotherapy with megavoltage x-ray beams.

  19. Integral window/photon beam position monitor and beam flux detectors for x-ray beams

    DOE Patents [OSTI]

    Shu, Deming (Darien, IL); Kuzay, Tuncer M. (Naperville, IL)

    1995-01-01

    A monitor/detector assembly in a synchrotron for either monitoring the position of a photon beam or detecting beam flux may additionally function as a vacuum barrier between the front end and downstream segment of the beamline in the synchrotron. A base flange of the monitor/detector assembly is formed of oxygen free copper with a central opening covered by a window foil that is fused thereon. The window foil is made of man-made materials, such as chemical vapor deposition diamond or cubic boron nitrate and in certain configurations includes a central opening through which the beams are transmitted. Sensors of low atomic number materials, such as aluminum or beryllium, are laid on the window foil. The configuration of the sensors on the window foil may be varied depending on the function to be performed. A contact plate of insulating material, such as aluminum oxide, is secured to the base flange and is thereby clamped against the sensor on the window foil. The sensor is coupled to external electronic signal processing devices via a gold or silver lead printed onto the contact plate and a copper post screw or alternatively via a copper screw and a copper spring that can be inserted through the contact plate and coupled to the sensors. In an alternate embodiment of the monitor/detector assembly, the sensors are sandwiched between the window foil of chemical vapor deposition diamond or cubic boron nitrate and a front foil made of similar material.

  20. Numerical simulation to study the transient self focusing of laser beam in plasma

    SciTech Connect (OSTI)

    Sharma, R. P.; Hussain, Saba Gaur, Nidhi

    2015-02-15

    In this paper, we present the numerical simulation for the coupled system of equations governing the dynamics of laser and Ion Acoustic Wave (IAW) in a collisionless plasma, when the coupling between the waves is through ponderomotive non-linearity. The nonlinear evolution of the laser beam is studied when the pump laser is perturbed by a periodic perturbation. By changing the perturbation wave number, we have studied its effect on the nonlinear evolution pattern of laser beam. In order to have a physical insight into the nonlinear dynamics of laser beam evolution in time and space, we have studied the laser and IAW spectra containing spatial harmonics. The magnitude of these harmonics changes with time and leads to time dependent localization of laser beam in spatial domain. The nonlinear dynamics of this localization is investigated in detail by using simulation and a semi-analytical model.

  1. Interaction of nonthermal muon beam with electron-positron-photon plasma: A thermal field theory approach

    SciTech Connect (OSTI)

    Noorian, Zainab; Eslami, Parvin; Javidan, Kurosh

    2013-11-15

    Interaction of a muon beam with hot dense QED plasma is investigated. Plasma system contains electrons and positrons with Fermi-Dirac distribution and Bose-Einstein distributed photons while the beam particles have nonthermal distribution. The energy loss of the beam particles during the interaction with plasma is calculated to complete leading order of interaction in terms of the QED coupling constant using thermal field theory approach. The screening effects of the plasma are computed consistently using resummation of perturbation theory with hard thermal loop approximation according to the Braaten-Pisarski method. Time evolution of the plasma characteristics and also plasma identifications during the interaction are investigated. Effects of the nonthermal parameter of the beam distribution on the energy exchange and the evolution of plasma-beam system are also explained.

  2. Beam splitter and method for generating equal optical path length beams

    DOE Patents [OSTI]

    Qian, Shinan; Takacs, Peter

    2003-08-26

    The present invention is a beam splitter for splitting an incident beam into first and second beams so that the first and second beams have a fixed separation and are parallel upon exiting. The beam splitter includes a first prism, a second prism, and a film located between the prisms. The first prism is defined by a first thickness and a first perimeter which has a first major base. The second prism is defined by a second thickness and a second perimeter which has a second major base. The film is located between the first major base and the second major base for splitting the incident beam into the first and second beams. The first and second perimeters are right angle trapezoidal shaped. The beam splitter is configured for generating equal optical path length beams.

  3. Simulation study of dynamic aperture with head-on beam-beam compensation in the RHIC

    SciTech Connect (OSTI)

    Luo, Y.; Fischer, W.

    2010-08-01

    In this note we summarize the calculated 10{sup 6} turn dynamic apertures with the proposed head-on beam-beam compensation in the Relativistic Heavy Ion Collider (RHIC). To compensate the head-on beam-beam effect in the RHIC 250 GeV polarized proton run, we are planning to introduce a DC electron beam with the same transverse profile as the proton beam to collide with the proton beam. Such a device to provide the electron beam is called an electron lens (e-lens). In this note we first present the optics and beam parameters and the tracking setup. Then we compare the calculated dynamic apertures without and with head-on beam-beam compensation. The effects of adjusted phase advances between IP8 and the center of e-lens and second order chromaticity correction are checked. In the end we will scan the proton and electron beam parameters with head-on beam-beam compensation.

  4. Heuristic optimization of the scanning path of particle therapy beams

    SciTech Connect (OSTI)

    Pardo, J.; Donetti, M.; Bourhaleb, F.; Ansarinejad, A.; Attili, A.; Cirio, R.; Garella, M. A.; Giordanengo, S.; Givehchi, N.; La Rosa, A.; Marchetto, F.; Monaco, V.; Pecka, A.; Peroni, C.; Russo, G.; Sacchi, R.

    2009-06-15

    Quasidiscrete scanning is a delivery strategy for proton and ion beam therapy in which the beam is turned off when a slice is finished and a new energy must be set but not during the scanning between consecutive spots. Different scanning paths lead to different dose distributions due to the contribution of the unintended transit dose between spots. In this work an algorithm to optimize the scanning path for quasidiscrete scanned beams is presented. The classical simulated annealing algorithm is used. It is a heuristic algorithm frequently used in combinatorial optimization problems, which allows us to obtain nearly optimal solutions in acceptable running times. A study focused on the best choice of operational parameters on which the algorithm performance depends is presented. The convergence properties of the algorithm have been further improved by using the next-neighbor algorithm to generate the starting paths. Scanning paths for two clinical treatments have been optimized. The optimized paths are found to be shorter than the back-and-forth, top-to-bottom (zigzag) paths generally provided by the treatment planning systems. The gamma method has been applied to quantify the improvement achieved on the dose distribution. Results show a reduction of the transit dose when the optimized paths are used. The benefit is clear especially when the fluence per spot is low, as in the case of repainting. The minimization of the transit dose can potentially allow the use of higher beam intensities, thus decreasing the treatment time. The algorithm implemented for this work can optimize efficiently the scanning path of quasidiscrete scanned particle beams. Optimized scanning paths decrease the transit dose and lead to better dose distributions.

  5. Nuclear astrophysics and electron beams

    SciTech Connect (OSTI)

    Schwenk, A.

    2013-11-07

    Electron beams provide important probes and constraints for nuclear astrophysics. This is especially exciting at energies within the regime of chiral effective field theory (EFT), which provides a systematic expansion for nuclear forces and electroweak operators based on quantum chromodynamics. This talk discusses some recent highlights and future directions based on chiral EFT, including nuclear structure and reactions for astrophysics, the neutron skin and constraints for the properties of neutron-rich matter in neutron stars and core-collapse supernovae, and the dark matter response of nuclei.

  6. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-12-03

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  7. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

    2013-06-25

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  8. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A. (Riverside, CA); Beloussov, Alexandre V. (San Bernardino, CA); Bakir, Julide (Alta Loma, CA); Armon, Deganit (Longmeadow, MA); Olsen, Howard B. (Irvine, CA); Salem, Dana (Riverside, CA)

    2010-09-21

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  9. Proton beam therapy control system

    DOE Patents [OSTI]

    Baumann, Michael A. (Riverside, CA); Beloussov, Alexandre V. (Bernardino, CA); Bakir, Julide (Alta Loma, CA); Armon, Deganit (Redlands, CA); Olsen, Howard B. (Colton, CA); Salem, Dana (Riverside, CA)

    2008-07-08

    A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

  10. Protective laser beam viewing device

    DOE Patents [OSTI]

    Neil, George R.; Jordan, Kevin Carl

    2012-12-18

    A protective laser beam viewing system or device including a camera selectively sensitive to laser light wavelengths and a viewing screen receiving images from the laser sensitive camera. According to a preferred embodiment of the invention, the camera is worn on the head of the user or incorporated into a goggle-type viewing display so that it is always aimed at the area of viewing interest to the user and the viewing screen is incorporated into a video display worn as goggles over the eyes of the user.

  11. Updated flux information for neutron scattering and irradiation facilities at the BNL High Flux Beam Reactor

    SciTech Connect (OSTI)

    Holden, N.E.; Hu, J.P.; Reciniello, R.N.; Sengupta, S.; Greenwood, L.R.; Farrell, K.

    1997-08-01

    The HFBR is a heavy water, D{sub 2}O, cooled and moderated reactor with twenty-eight fuel elements containing a maximum of 9.8 kilograms of {sup 235}U. While most reactors attempt to minimize the escape of neutrons from the core, the HFBR`s D{sub 2}O design allows the thermal neutron flux to peak in the reflector region and maximizes the number of thermal neutrons available to nine horizontal external beams, H-1 to H-9, used for neutron scattering and capture reactions, supporting physics, chemistry and biology experiments. All horizontal beam tubes were built tangential to the direction of the emerging neutrons, except for the H-2 beam tube, which looks directly at the core and has been used for neutron cross section measurements utilizing fast neutrons and for the TRISTAN fission product studies. In recent years, there have been some beam modifications and new instrumentation introduced at the HFBR. A high resolution neutron powder diffractometer instrument is now operating with a resolution of 5 {times} 10{sup {minus}4} at horizontal beam line H-1. To study scattering from liquid surfaces, a neutron reflection spectrometer was introduced on the CNF beam line at H-9. In the past year, a fourth beam line has been added to the CNF line at H-9. The existing beam plug at the H-6 beam line has recently been removed and a new plug, which will feature super mirrored surfaces, is now being installed. Last year, the vertical beam thimble, V-13, a fixed port filled with thirty year old samples used for HFBR material surveillance studies was replaced by a new thimble and charging station at the core edge creating an irradiation facility to substitute for the original V-13. A neutron dosimetry program has begun to measure and calculate the energy dependent neutron and gamma ray flux densities and/or dose rates at horizontal beam lines and vertical irradiation thimbles.

  12. Projection imaging of photon beams by the Cerenkov effect

    SciTech Connect (OSTI)

    Glaser, Adam K.; Davis, Scott C.; McClatchy, David M.; Zhang, Rongxiao; Pogue, Brian W.; Gladstone, David J.

    2013-01-15

    Purpose: A novel technique for beam profiling of megavoltage photon beams was investigated for the first time by capturing images of the induced Cerenkov emission in water, as a potential surrogate for the imparted dose in irradiated media. Methods: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire 2D projection images of Cerenkov emission from a 4 Multiplication-Sign 4 cm{sup 2} 6 MV linear accelerator (LINAC) x-ray photon beam operating at a dose rate of 400 MU/min incident on a water tank with transparent walls. The ICCD acquisition was gated to the LINAC sync pulse to reduce background light artifacts, and the measurement quality was investigated by evaluating the signal to noise ratio and measurement repeatability as a function of delivered dose. Monte Carlo simulations were used to derive a calibration factor for differences between the optical images and deposited dose arising from the anisotropic angular dependence of Cerenkov emission. Finally, Cerenkov-based beam profiles were compared to a percent depth dose (PDD) and lateral dose profile at a depth of d{sub max} from a reference dose distribution generated from the clinical Varian ECLIPSE treatment planning system (TPS). Results: The signal to noise ratio was found to be 20 at a delivered dose of 66.6 cGy, and proportional to the square root of the delivered dose as expected from Poisson photon counting statistics. A 2.1% mean standard deviation and 5.6% maximum variation in successive measurements were observed, and the Monte Carlo derived calibration factor resulted in Cerenkov emission images which were directly correlated to deposited dose, with some spatial issues. The dose difference between the TPS and PDD predicted by Cerenkov measurements was within 20% in the buildup region with a distance to agreement (DTA) of 1.5-2 mm and {+-}3% at depths beyond d{sub max}. In the lateral profile, the dose difference at the beam penumbra was within {+-}13% with a DTA of 0-2 mm, {+-}5% in the central beam region, and 2%-3% in the beam umbra. Conclusions: The results from this initial study demonstrate the first documented use of Cerenkov emission imaging to profile x-ray photon LINAC beams in water. The proposed modality has several potential advantages over alternative methods, and upon future refinement may prove to be a robust and novel dosimetry method.

  13. Effect of Beam-Beam Interactions on Stability of Coherent Oscillations in a

    Office of Scientific and Technical Information (OSTI)

    Muon Collider (Conference) | SciTech Connect Effect of Beam-Beam Interactions on Stability of Coherent Oscillations in a Muon Collider Citation Details In-Document Search Title: Effect of Beam-Beam Interactions on Stability of Coherent Oscillations in a Muon Collider In order to achieve peak luminosity of a muon collider in the 10{sup 34}/cm{sup 2}/s range the number of muons per bunch should be of the order of a few units of 10{sup 12} rendering the beam-beam parameter as high as 0.1 per

  14. STATUS OF THE RHIC HEAD-ON BEAM-BEAM COMPENSATION PROJECT

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Pikin, A.; Beebe, E.; Bruno, D.; Gassner, D.; Hocke, J.; Jain, A.; Lambiase, R.; Mapes, M.; Meng, W.; Montag, C.; Oerter, B.; Okamura, M.; Raparia, D.; Than, R.; Tuozzolo, J.

    2010-05-23

    In polarized proton operation the luminosity of RHIC is limited by the head-on beam-beam effect, and methods that mitigate the effect will result in higher peak and average luminosities. Two electron lenses, one for each ring, are being constructed to partially compensate the head-on beam-beam effect in the two rings. An electron lens consists of a low energy electron beam that creates the same amplitude dependent transverse kick as the proton beam. We discuss design considerations and present the main parameters.

  15. Extracting source parameters from beam monitors on a chopper spectrometer

    SciTech Connect (OSTI)

    Abernathy, Douglas L [ORNL; Niedziela, Jennifer L [ORNL; Stone, Matthew B [ORNL

    2015-01-01

    The intensity distributions of beam monitors in direct-geometry time-of-flight neutron spectrometers provide important information about the instrument resolution. For short-pulse spallation neutron sources in particular, the asymmetry of the source pulse may be extracted and compared to Monte Carlo source simulations. An explicit formula using a Gaussian-convolved Ikeda-Carpenter distribution is given and compared to data from the ARCS instrument at the Spallation Neutron Source.

  16. Conceptual design for the ZEPHYR neutral-beam injection system

    SciTech Connect (OSTI)

    Cooper, W.S.; Elischer, V.P.; Goldberg, D.A.; Hopkins, D.B.; Jacobson, V.L.; Lou, K.H.; Tanabe, J.T.

    1981-03-01

    In June 1980, the Lawrence Berkeley Laboratory began a conceptual design study for a neutral beam injection system for the ZEPHYR ignition tokamak proposed by the Max-Planck-Institut fur Plasmaphysik in Garching, Germany. The ZEPHYR project was cancelled, and the LBL design effort concluded prematurely in January 1981. This report describes the conceptual design as it existed at that time, and gives brief consideration to a schedule, but does not deal with costs.

  17. Particle-in-cell simulations of electron beam control using an inductive current divider

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

    Swanekamp, S. B.; Angus, J. R.; Cooperstein, G.; Ottinger, P. F.; Richardson, A. S.; Schumer, J. W.; Weber, B. V.

    2015-11-18

    Kinetic, time-dependent, electromagnetic, particle-in-cell simulations of the inductive current divider are presented. The inductive current divider is a passive method for controlling the trajectory of an intense, hollow electron beam using a vacuum structure that inductively splits the beam’s return current. The current divider concept was proposed and studied theoretically in a previous publication [Phys. Plasmas 22, 023107 (2015)] A central post carries a portion of the return current (I1) while the outer conductor carries the remainder (I2) with the injected beam current given by Ib=I1+I2. The simulations are in agreement with the theory which predicts that the total forcemore » on the beam trajectory is proportional to (I2-I1) and the force on the beam envelope is proportional to Ib. For a fixed central post, the beam trajectory is controlled by varying the outer conductor radius which changes the inductance in the return-current path. The simulations show that the beam emittance is approximately constant as the beam propagates through the current divider to the target. As a result, independent control over both the current density and the beam angle at the target is possible by choosing the appropriate return-current geometry.« less

  18. Design of the low energy beam transport line between CARIBU and the EBIS charge breeder

    SciTech Connect (OSTI)

    Perry, A.; Ostroumov, P. N.; Barcikowski, A.; Dickerson, C.; Kondrashev, S. A.; Mustapha, B.; Savard, G.

    2015-01-09

    An Electron Beam Ion Source Charge Breeder (EBIS-CB) has been developed to breed radioactive beams from the CAlifornium Rare Isotope Breeder Upgrade (CARIBU) facility at ATLAS. The EBIS-CB will replace the existing ECR charge breeder to increase the intensity and improve the purity of reaccelerated radioactive ion beams. The EBIS-CB is in the final stage of off-line commissioning. Currently, we are developing a low energy beam transport (LEBT) system to transfer CARIBU beams to the EBIS-CB. As was originally planned, an RFQ cooler-buncher will precede the EBIS-CB. Recently, it was decided to include a multi-reflection time-of-flight (MR-TOF) mass-spectrometer following the RFQ. MR-TOF is a relatively new technology used to purify beams with a mass-resolving power up to 310{sup 5} as was demonstrated in experiments at CERN/ISOLDE. Very high purity singly-charged radioactive ion beams will be injected into the EBIS for charge breeding and due to its inherent properties, the EBIS-CB will maintain the purity of the charge bred beams. Possible contamination of residual gas ions will be greatly suppressed by achieving ultra-high vacuum in the EBIS trap. This paper will present and discuss the design of the LEBT and the overall integration of the EBIS-CB into ATLAS.

  19. Experimental measurement of the 4-d transverse phase space map of a heavy ion beam

    SciTech Connect (OSTI)

    Hopkins, H S

    1997-12-01

    The development and employment of a new diagnostic instrument for characterizing intense, heavy ion beams is reported on. This instrument, the ''Gated Beam Imager'' or ''GBI'' was designed for use on Lawrence Livermore National Laboratory Heavy Ion Fusion Project's ''Small Recirculator'', an integrated, scaled physics experiment and engineering development project for studying the transport and control of intense heavy ion beams as inertial fusion drivers in the production of electric power. The GBI allows rapid measurement and calculation of a heavy ion beam's characteristics to include all the first and second moments of the transverse phase space distribution, transverse emittance, envelope parameters and beam centroid. The GBI, with appropriate gating produces a time history of the beam resulting in a 4-D phase-space and time ''map'' of the beam. A unique capability of the GBI over existing diagnostic instruments is its ability to measure the ''cross'' moments between the two transverse orthogonal directions. Non-zero ''cross'' moments in the alternating gradient lattice of the Small Recirculator are indicative of focusing element rotational misalignments contributing to beam emittance growth. This emittance growth, while having the same effect on the ability to focus a beam as emittance growth caused by non-linear effects, is in principle removable by an appropriate number of focusing elements. The instrument uses the pepperpot method of introducing a plate with many pinholes into the beam and observing the images of the resulting beamlets as they interact with a detector after an appropriate drift distance. In order to produce adequate optical signal and repeatability, the detector was chosen to be a microchannel plate (MCP) with a phosphor readout screen. The heavy ions in the pepperpot beamlets are stopped in the MCP's thin front metal anode and the resulting secondary electron signal is amplified and proximity-focused onto the phosphor while maintaining the spatial and intensity characteristics of the heavy ion beamlets. The MCP used in this manner is a sensitive, accurate, and long-lasting detector, resistant against signal degradation experienced by previous methods of intense heavy ion beam detection and imaging. The performance of the GBI was benchmarked against existing mechanical emittance diagnostics and the results of sophisticated beam transport numerical simulation codes to demonstrate its usefulness as a diagnostic tool. A method of beam correction to remove the effects of quadrupole focusing element rotational misalignments is proposed using data obtainable from a GBI. An optimizing code was written to determine the parameters of the correction system elements based on input from the GBI. The results of this code for the Small Recirculator beam are reported on.

  20. Construction of Industrial Electron Beam Plant for Wastewater Treatment

    SciTech Connect (OSTI)

    Han, B.; Kim, J.; Kim, Y.; Kim, S.; Lee, M.; Choi, J.; Ahn, S.; Makarov, I.E.; Ponomarev, A.V.

    2004-10-06

    A pilot plant for treating 1,000 m3/day of dyeing wastewater with e-beam has been constructed and operated since 1998 in Daegu, Korea together with the biological treatment facility. The wastewater from various stages of the existing purification process has been treated with electron beam in this plant, and it gave rise to elaborate the optimal technology of the electron beam treatment of wastewater with increased reliability at instant changes in the composition of wastewater. Installation of the e-beam pilot plant resulted in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable to reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in flow rate limit of existing facilities by 30-40%. Industrial plant for treating 10,000 m3/day, based upon the pilot experimental result, is under construction and will be finished by 2005. This project is supported by the International Atomic Energy Agency (IAEA) and Korean Government.

  1. Focused electron and ion beam systems

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Reijonen, Jani; Persaud, Arun; Ji, Qing; Jiang, Ximan

    2004-07-27

    An electron beam system is based on a plasma generator in a plasma ion source with an accelerator column. The electrons are extracted from a plasma cathode in a plasma ion source, e.g. a multicusp plasma ion source. The beam can be scanned in both the x and y directions, and the system can be operated with multiple beamlets. A compact focused ion or electron beam system has a plasma ion source and an all-electrostatic beam acceleration and focusing column. The ion source is a small chamber with the plasma produced by radio-frequency (RF) induction discharge. The RF antenna is wound outside the chamber and connected to an RF supply. Ions or electrons can be extracted from the source. A multi-beam system has several sources of different species and an electron beam source.

  2. Radiation beam calorimetric power measurement system

    DOE Patents [OSTI]

    Baker, John (Livermore, CA); Collins, Leland F. (Pleasanton, CA); Kuklo, Thomas C. (Ripon, CA); Micali, James V. (Dublin, CA)

    1992-01-01

    A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

  3. Rippled beam free electron laser amplifier

    DOE Patents [OSTI]

    Carlsten, Bruce E. (Los Alamos, NM)

    1999-01-01

    A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

  4. Virtual mask digital electron beam lithography

    DOE Patents [OSTI]

    Baylor, L.R.; Thomas, C.E.; Voelkl, E.; Moore, J.A.; Simpson, M.L.; Paulus, M.J.

    1999-04-06

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made. 5 figs.

  5. Virtual mask digital electron beam lithography

    DOE Patents [OSTI]

    Baylor, Larry R. (Farragut, TN); Thomas, Clarence E. (Knoxville, TN); Voelkl, Edgar (Oak Ridge, TN); Moore, James A. (Powell, TN); Simpson, Michael L. (Knoxville, TN); Paulus, Michael J. (Knoxville, TN)

    1999-01-01

    Systems and methods for direct-to-digital holography are described. An apparatus includes a laser; a beamsplitter optically coupled to the laser; a reference beam mirror optically coupled to the beamsplitter; an object optically coupled to the beamsplitter, a focusing lens optically coupled to both the reference beam mirror and the object; and a digital recorder optically coupled to the focusing lens. A reference beam is incident upon the reference beam mirror at a non-normal angle, and the reference beam and an object beam are focused by the focusing lens at a focal plane of the digital recorder to form an image. The systems and methods provide advantages in that computer assisted holographic measurements can be made.

  6. Cylindrical target Li-beam-driven hohlraum experiments

    SciTech Connect (OSTI)

    Derzon, M.S.; Aubert, J.; Chandler, G.A.

    1998-06-01

    The authors performed a series of experiments on the Particle Beam Fusion Accelerator II (PBFA II) in May, 1994, and obtained a brightness temperature of 61 {+-} 2 eV for an ion-beam heated hohlraum. The hohlraum was a 4-mm-diameter, right-circular cylinder with a 1.5-mm-thick gold wall, a low-density CH foam fill, and a 1.5- or 3-mm-diameter diagnostic aperture in the top. The nominal parameters of the radially-incident PBFA II Li ion beam were 9 MeV peak energy ({approximately}10 MeV at the gas cell) at the target at a peak power of 2.5 {+-} 0.3 TW/cm{sup 2} and a 15 ns pulse width. Azimuthal variations in intensity of a factor of 3, with respect to the mean, were observed. Nonuniformities in thermal x-ray emission across the area of the diagnostic hole were also observed. Time-dependent hole-closure velocities were measured: the time-averaged velocity of {approximately}2 cm/{micro}s is in good agreement with sound speed estimates. Unfolded x-ray spectra and brightness temperatures as a function of time are reported and compared to simulations. Hole closure corrections are discussed with comparisons between XRD and bolometer measurements. Temperature scaling with power on target is also presented.

  7. Coherence delay augmented laser beam homogenizer

    DOE Patents [OSTI]

    Rasmussen, P.; Bernhardt, A.

    1993-06-29

    The geometrical restrictions on a laser beam homogenizer are relaxed by ug a coherence delay line to separate a coherent input beam into several components each having a path length difference equal to a multiple of the coherence length with respect to the other components. The components recombine incoherently at the output of the homogenizer, and the resultant beam has a more uniform spatial intensity suitable for microlithography and laser pantogography. Also disclosed is a variable aperture homogenizer, and a liquid filled homogenizer.

  8. Coherence delay augmented laser beam homogenizer

    DOE Patents [OSTI]

    Rasmussen, Paul (Livermore, CA); Bernhardt, Anthony (Berkeley, CA)

    1993-01-01

    The geometrical restrictions on a laser beam homogenizer are relaxed by ug a coherence delay line to separate a coherent input beam into several components each having a path length difference equal to a multiple of the coherence length with respect to the other components. The components recombine incoherently at the output of the homogenizer, and the resultant beam has a more uniform spatial intensity suitable for microlithography and laser pantogography. Also disclosed is a variable aperture homogenizer, and a liquid filled homogenizer.

  9. Focused ion beam source method and apparatus

    DOE Patents [OSTI]

    Pellin, Michael J. (Naperville, IL); Lykke, Keith R. (Gaithersburg, MD); Lill, Thorsten B. (Sunnyvale, CA)

    2000-01-01

    A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.

  10. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, L.A.; Dane, C.B.

    1993-08-24

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  11. Beam Characterization at the Neutron Radiography Facility

    SciTech Connect (OSTI)

    Sarah Morgan; Jeffrey King

    2013-01-01

    The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beams effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beams effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the models energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

  12. PARTICLE ACCELERATORS; ACCELERATORS; BEAM DUMPS; BENDING; CHANNELING...

    Office of Scientific and Technical Information (OSTI)

    Channeling through Bent Crystals Mack, Stephanie; Ottawa U. SLAC 43 PARTICLE ACCELERATORS; ACCELERATORS; BEAM DUMPS; BENDING; CHANNELING; CRYSTAL LATTICES; DETECTION; FORTRAN;...

  13. PowerBeam Inc | Open Energy Information

    Open Energy Info (EERE)

    Product: PowerBeam holds the patent to a power transmission technology that produces wireless electricity. Coordinates: 32.780338, -96.547405 Show Map Loading map......

  14. Probing Organic Transistors with Infrared Beams

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

    Probing Organic Transistors with Infrared Beams Print Silicon-based transistors are well-understood, basic components of contemporary electronic technology. In contrast, there is...

  15. High power, high beam quality regenerative amplifier

    DOE Patents [OSTI]

    Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

    1993-01-01

    A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

  16. Raman beam combining for laser brightness enhancement

    DOE Patents [OSTI]

    Dawson, Jay W.; Allen, Graham S.; Pax, Paul H.; Heebner, John E.; Sridharan, Arun K.; Rubenchik, Alexander M.; Barty, Chrisopher B. J.

    2015-10-27

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  17. Raman beam combining for laser brightness enhancement

    DOE Patents [OSTI]

    Dawson, Jay W; Allen, Grahan S; Pax, Paul H; Heebner, John E; Sridharan, Arun K; Rubenchik, Alexander M; Barty, Christopher B.J

    2015-11-05

    An optical source capable of enhanced scaling of pulse energy and brightness utilizes an ensemble of single-aperture fiber lasers as pump sources, with each such fiber laser operating at acceptable pulse energy levels. Beam combining involves stimulated Raman scattering using a Stokes' shifted seed beam, the latter of which is optimized in terms of its temporal and spectral properties. Beams from fiber lasers can thus be combined to attain pulses with peak energies in excess of the fiber laser self-focusing limit of 4 MW while retaining the advantages of a fiber laser system of high average power with good beam quality.

  18. Plasma formed ion beam projection lithography system

    DOE Patents [OSTI]

    Leung, Ka-Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA); Ngo, Vinh (San Jose, CA); Zahir, Nastaran (Greenbrae, CA)

    2002-01-01

    A plasma-formed ion-beam projection lithography (IPL) system eliminates the acceleration stage between the ion source and stencil mask of a conventional IPL system. Instead a much thicker mask is used as a beam forming or extraction electrode, positioned next to the plasma in the ion source. Thus the entire beam forming electrode or mask is illuminated uniformly with the source plasma. The extracted beam passes through an acceleration and reduction stage onto the resist coated wafer. Low energy ions, about 30 eV, pass through the mask, minimizing heating, scattering, and sputtering.

  19. The use of intensity-modulated radiation therapy photon beams for improving the dose uniformity of electron beams shaped with MLC

    SciTech Connect (OSTI)

    Mosalaei, Homeira; Karnas, Scott; Shah, Sheel; Van Doodewaard, Sharon; Foster, Tim; Chen, Jeff

    2012-04-01

    Electrons are ideal for treating shallow tumors and sparing adjacent normal tissue. Conventionally, electron beams are collimated by cut-outs that are time-consuming to make and difficult to adapt to tumor shape throughout the course of treatment. We propose that electron cut-outs can be replaced using photon multileaf collimator (MLC). Two major problems of this approach are that the scattering of electrons causes penumbra widening because of a large air gap, and available commercial treatment planning systems (TPSs) do not support MLC-collimated electron beams. In this study, these difficulties were overcome by (1) modeling electron beams collimated by photon MLC for a commercial TPS, and (2) developing a technique to reduce electron beam penumbra by adding low-energy intensity-modulated radiation therapy (IMRT) photons (4 MV). We used blocks to simulate MLC shielding in the TPS. Inverse planning was used to optimize boost photon beams. This technique was applied to a parotid and a central nervous system (CNS) clinical case. Combined photon and electron plans were compared with conventional plans and verified using ion chamber, film, and a 2D diode array. Our studies showed that the beam penumbra for mixed beams with 90 cm source to surface distance (SSD) is comparable with electron applicators and cut-outs at 100 cm SSD. Our mixed-beam technique yielded more uniform dose to the planning target volume and lower doses to various organs at risk for both parotid and CNS clinical cases. The plans were verified with measurements, with more than 95% points passing the gamma criteria of 5% in dose difference and 5 mm for distance to agreement. In conclusion, the study has demonstrated the feasibility and potential advantage of using photon MLC to collimate electron beams with boost photon IMRT fields.

  20. Beam losses due to abrupt crab cavity failures in the LHC

    SciTech Connect (OSTI)

    Baer, T.; Barranco, J.; Calaga, R.; Tomas, R.; Wenninger, B.; Yee, B.; Zimmermann, F.

    2011-03-28

    A major concern for the implementation of crab crossing in a future High-Luminosity LHC (HL-LHC) is machine protection in an event of a fast crab-cavity failure. Certain types of abrupt crab-cavity amplitude and phase changes are simulated to characterize the effect of failures on the beam and the resulting particle-loss signatures. The time-dependent beam loss distributions around the ring and particle trajectories obtained from the simulations allow for a first assessment of the resulting beam impact on LHC collimators and on sensitive components around the ring. Results for the nominal LHC lattice is presented.

  1. Anomalous deflection of a charged-particle beam by bent crystals

    SciTech Connect (OSTI)

    Taratin, A.M.; Vorobev, S.A.

    1986-05-01

    Using computer simulations of particle trajectory, a deflection of part of the beam in the direction opposite to the curvature is discovered for charged particles passing through a bent crystal. The passage of a proton beam of energy E(0) = 1 GeV through a curved silicon single crystal is considered, and only particles that move through the single crystal in a quasi-channel mode are deflected. It is suggested that the observed anomalous deflection can be used to deflect beams of high energy charged particles through angles that are tens of times greater than the critical angle for channeling, with application to experimental nuclear physics. 6 references.

  2. Linear beam raster magnet driver based on H-bridge technique

    DOE Patents [OSTI]

    Sinkine, Nikolai I.; Yan, Chen; Apeldoorn, Cornelis; Dail, Jeffrey Glenn; Wojcik, Randolph Frank; Gunning, William

    2006-06-06

    An improved raster magnet driver for a linear particle beam is based on an H-bridge technique. Four branches of power HEXFETs form a two-by-two switch. Switching the HEXFETs in a predetermined order and at the right frequency produces a triangular current waveform. An H-bridge controller controls switching sequence and timing. The magnetic field of the coil follows the shape of the waveform and thus steers the beam using a triangular rather than a sinusoidal waveform. The system produces a raster pattern having a highly uniform raster density distribution, eliminates target heating from non-uniform raster density distributions, and produces higher levels of beam current.

  3. Stripline fast faraday cup for measuring GHz structure of ion beams

    DOE Patents [OSTI]

    Bogaty, John M. (Lombard, IL)

    1992-01-01

    The Stripline Fast Faraday Cup is a device which is used to quantitatively and qualitatively measure gigahertz time structure characteristics of ion beams with energies up to at least 30 Mev per nucleon. A stripline geometry is employed in conjunction with an electrostatic screen and a Faraday cup to provide for analysis of the structural characteristics of an ion beam. The stripline geometry allows for a large reduction in the size of the instrument while the electrostatic screen permits measurements of the properties associated with low speed ion beams.

  4. First Beam Waist Measurements in the Final Focus Beam Line at...

    Office of Scientific and Technical Information (OSTI)

    KEK Accelerator Test Facility Citation Details In-Document Search Title: First Beam Waist Measurements in the Final Focus Beam Line at the KEK Accelerator Test Facility The ATF2 ...

  5. Head-on beam-beam compensation with electron lenses in the RHIC.

    SciTech Connect (OSTI)

    Luo,Y.; FischW; Abreu, N.; Beebe, E.; Montag, C.; Okamura, M.; Pikin, A.; Robert-Demolaize, G.

    2008-06-23

    The working point for the polarized proton run in the Relativistic Heavy Ion Collider is constrained between 2/3 and 7/10 in order to maintain good beam lifetime and polarization. To further increase the bunch intensity to improve the luminosity, a low energy Gaussian electron beam, or an electron lens is proposed to head-on collide with the proton beam to compensate the large tune shift and tune spread generated by the proton-proton beam-beam interactions at IP6 and IP8. In this article, we outline the scheme of head-on beam-beam compensation in the RHIC and give the layout of e-lens installation and the parameters of the proton and electron beams. The involved physics and engineering issues are shortly discussed.

  6. Method and apparatus for laser-controlled proton beam radiology

    DOE Patents [OSTI]

    Johnstone, Carol J.

    1998-01-01

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

  7. Method and apparatus for laser-controlled proton beam radiology

    DOE Patents [OSTI]

    Johnstone, C.J.

    1998-06-02

    A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H{sup {minus}} beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H{sup {minus}} beam and laser beam to produce a neutral beam therefrom within a subsection of the H{sup {minus}} beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H{sup {minus}} beam in order to form the neutral beam in subsections of the H{sup {minus}} beam. As the scanning laser moves across the H{sup {minus}} beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser. 9 figs.

  8. Simulations of coherent beam-beam effects with head-on compensation

    SciTech Connect (OSTI)

    White S.; Fischer, W.; Luo. Y.

    2012-05-20

    Electron lenses are under construction for installation in RHIC in order to mitigate the head-on beam-beam effects. This would allow operation with higher bunch intensity and result in a significant increase in luminosity. We report on recent strong-strong simulations and experiments that were carried out using the RHIC upgrade parameters to assess the impact of coherent beam-beam effects in the presence of head-on compensation.

  9. Lattice design for head-on beam-beam compensation at RHIC

    SciTech Connect (OSTI)

    Montag, C.

    2011-03-28

    Electron lenses for head-on beam-beam compensation will be installed in IP 10 at RHIC. Compensation of the beam-beam effect experienced at IP 8 requires betatron phase advances of {Delta}{psi} = k {center_dot} {pi} between the proton-proton interaction point at IP 8, and the electron lens at IP 10. This paper describes the lattice solutions for both the BLUE and the YELLOW ring to achieve this goal.

  10. Time-of-flight direct recoil ion scattering spectrometer

    DOE Patents [OSTI]

    Krauss, Alan R. (Naperville, IL); Gruen, Dieter M. (Downers Grove, IL); Lamich, George J. (Orland Park, IL)

    1994-01-01

    A time of flight direct recoil and ion scattering spectrometer beam line (10). The beam line (10) includes an ion source (12) which injects ions into pulse deflection regions (14) and (16) separated by a drift space (18). A final optics stage includes an ion lens and deflection plate assembly (22). The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions (14) and (16).

  11. Time-of-flight direct recoil ion scattering spectrometer

    DOE Patents [OSTI]

    Krauss, A.R.; Gruen, D.M.; Lamich, G.J.

    1994-09-13

    A time-of-flight direct recoil and ion scattering spectrometer beam line is disclosed. The beam line includes an ion source which injects ions into pulse deflection regions and separated by a drift space. A final optics stage includes an ion lens and deflection plate assembly. The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions. 23 figs.

  12. Study of beam loading and its compensation in the Compact Ultrafast Terahertz Free-Electron Laser injector linac

    SciTech Connect (OSTI)

    Lal, Shankar Pant, K. K.

    2014-12-15

    The RF properties of an accelerating structure, and the pulse structure and charge per bunch in the electron beam propagating through it are important parameters that determine the impact of beam loading in the structure. The injector linac of the Compact Ultrafast Terahertz Free-Electron Laser (CUTE-FEL) has been operated with two different pulse structures during initial commissioning experiments and the effect of beam loading on the accelerated electron beam parameters has been studied analytically for these two pulse structures. This paper discusses the analytical study of beam loading in a Standing Wave, Plane Wave Transformer linac employed in the CUTE-FEL setup, and a possible technique for its compensation for the electron beam parameters of the CUTE-FEL. A parametric study has been performed to study beam loading for different beam currents and to optimize injection time of the electron beam to compensate beam loading. Results from the parametric study have also been used to explain previously observed results from acceleration experiments in the CUTE-FEL setup.

  13. Low energy beam transport system developments

    SciTech Connect (OSTI)

    Dudnikov, V.; Han, B.; Stockli, M.; Welton, R.; Dudnikova, G.

    2015-04-08

    For high brightness beam production it is important to preserve the brightness in the low energy beam transport system (LEBT) used to transport and match the ion beams to the next stage of acceleration, usually an RFQ. While electrostatic focusing can be problematic for high current beam transport, reliable electrostatic LEBT operation has been demonstrated with H{sup ?} beams up to 60?mA. Now, however, it is commonly accepted that an optimal LEBT for high current accelerator applications consists of focusing solenoids with space charge compensation. Two-solenoid LEBTs are successfully used for high current (>100?mA) proton beam transport. Preservation of low emittances (~0.15 ? mm-mrad) requires the addition of a heavy gas (Xe, Kr), which causes ~5% of proton loss in a 1?m long LEBT. Similar Xe densities would be required to preserve low emittances of H{sup ?} beams, but such gas densities cause unacceptably high H{sup ?} beam losses. A short LEBT with only one short solenoid, movable for RFQ matching, can be used for reduced negative ion stripping. A strong electrostatic-focusing LEBT has been successfully adopted for transport of high current H{sup ?} beams in the SNS Front End. Some modifications of such electrostatic LEBTs are expected to improve the reliable transport of intense positive and negative ion beams without greatly degrading their low emittances. We concentrate on processes that determine the beam brightness degradation and on their prevention. Proposed improvements to the SNS electrostatic LEBT are discussed.

  14. Electron lenses for compensation of beam-beam effects: Tevatron, RHIC, LHC

    SciTech Connect (OSTI)

    Shiltsev, V.; /Fermilab

    2007-12-01

    Since previous BEAM'06 workshop a year ago, significant progress has been made in the field of beam-beam compensation (BBC)--it has been experimentally demonstrated that both Tevatron Electron Lenses (TEL) significantly improve proton and luminosity lifetimes in high-luminosity stores. This article summarizes these results and discusses prospects of the BBC in Tevatron, RHIC and LHC.

  15. Cascaded injection resonator for coherent beam combining of laser arrays

    DOE Patents [OSTI]

    Kireev, Vassili [Sunnyvale, CA; Liu, Yun; Protopopescu, Vladimir [Knoxville, TN; Braiman, Yehuda [Oak Ridge, TN

    2008-10-21

    The invention provides a cascaded injection resonator for coherent beam combining of laser arrays. The resonator comprises a plurality of laser emitters arranged along at least one plane and a beam sampler for reflecting at least a portion of each laser beam that impinges on the beam sampler, the portion of each laser beam from one of the laser emitters being reflected back to another one of the laser emitters to cause a beam to be generated from the other one of the laser emitters to the beam reflector. The beam sampler also transmits a portion of each laser beam to produce a laser output beam such that a plurality of laser output beams of the same frequency are produced. An injection laser beam is directed to a first laser emitter to begin a process of generating and reflecting a laser beam from one laser emitter to another laser emitter in the plurality. A method of practicing the invention is also disclosed.

  16. Tevatron End-of-Run Beam Physics Experiments

    SciTech Connect (OSTI)

    Valishev, A.; Gu, X.; Miyamoto, R.; White, S.; Schmidt, F.; Qiang, J.; /LBNL

    2012-05-01

    Before the Tevatron Collider Run II ended in September of 2011, a number of specialized beam study periods were dedicated to the experiments on various accelerator physics concepts and effects during the last year of the machine operation. The study topics included collimation with bent crystals and hollow electron beams, diffusion measurements and various aspects of beam-beam interactions. In this report we concentrate on the subject of beam-beam interactions, summarizing the results of beam experiments. The covered topics include offset collisions, coherent beam stability, effect of the bunch-length-to-beta-function ratio, and operation of AC dipole with colliding beams.

  17. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOE Patents [OSTI]

    Karl, Jr., Robert R. (Los Alamos, NM)

    1990-01-01

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  18. Note: Effect of hot liner in producing {sup 40,48}Ca beam from RIKEN 18-GHz electron cyclotron resonance ion source

    SciTech Connect (OSTI)

    Ozeki, K. Higurashi, Y.; Kidera, M.; Nakagawa, T.

    2015-01-15

    In order to produce a high-intensity and stable {sup 48}Ca beam from the RIKEN 18-GHz electron cyclotron resonance ion source, we have begun testing the production of a calcium beam using a micro-oven. To minimize the consumption rate of the material ({sup 48}Ca), we introduced the hot liner method and investigated the effect of the liner on the material consumption rate. The micro-oven was first used to produce the {sup 48}Ca beam for experiments in the RIKEN radioisotope beam factory, and a stable beam could be supplied for a long time with low consumption rate.

  19. Polarization of fast particle beams by collisional pumping

    DOE Patents [OSTI]

    Stearns, J. Warren (Castro Valley, CA); Kaplan, Selig N. (El Cerrito, CA); Pyle, Robert V. (Berkeley, CA); Anderson, L. Wilmer (Madison, WI); Ruby, Lawrence (Berkeley, CA); Schlachter, Alfred S. (Oakland, CA)

    1988-01-01

    Method and apparatus for highly polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and also generating a thick electron-spin-polarized medium positioned as a target for the beam. The target is made sufficiently thick to allow the beam to interact with the medium to produce collisional pumping whereby the beam becomes highly polarized.

  20. A machine protection beam position monitor system

    SciTech Connect (OSTI)

    Medvedko, E.; Smith, S.; Fisher, A.

    1998-12-10

    Loss of the stored beam in an uncontrolled manner can cause damage to the PEP-II B Factory. We describe here a device which detects large beam position excursions or unexpected beam loss and triggers the beam abort system to extract the stored beam safely. The bad-orbit abort trigger beam position monitor (BOAT BPM) generates a trigger when the beam orbit is far off the center (>20 mm), or rapid beam current loss (dI/dT) is detected. The BOAT BPM averages the input signal over one turn (136 kHz). AM demodulation is used to convert input signals at 476 MHz to baseband voltages. The detected signal goes to a filter section for suppression of the revolution frequency, then on to amplifiers, dividers, and comparators for position and current measurements and triggering. The derived current signal goes to a special filter, designed to perform dI/dT monitoring at fast, medium, and slow current loss rates. The BOAT BPM prototype test results confirm the design concepts.

  1. A machine protection beam position monitor system

    SciTech Connect (OSTI)

    Medvedko, E.; Smith, S.; Fisher, A.

    1998-12-01

    Loss of the stored beam in an uncontrolled manner can cause damage to the PEP-II {ital B} Factory. We describe here a device which detects large beam position excursions or unexpected beam loss and triggers the beam abort system to extract the stored beam safely. The bad-orbit abort trigger beam position monitor (BOAT BPM) generates a trigger when the beam orbit is far off the center ({gt}20 mm), or rapid beam current loss (dI/dT) is detected. The BOAT BPM averages the input signal over one turn (136 kHz). AM demodulation is used to convert input signals at 476 MHz to baseband voltages. The detected signal goes to a filter section for suppression of the revolution frequency, then on to amplifiers, dividers, and comparators for position and current measurements and triggering. The derived current signal goes to a special filter, designed to perform dI/dT monitoring at fast, medium, and slow current loss rates. The BOAT BPM prototype test results confirm the design concepts. {copyright} {ital 1998 American Institute of Physics.}

  2. W-Band Sheet Beam Klystron Simulation

    SciTech Connect (OSTI)

    Colby, E.R.; Caryotakis, G.; Fowkes, W.R.; /SLAC; Smithe, D.N.; /Mission Res., Newington

    2005-09-12

    With the development of ever higher energy particle accelerators comes the need for compactness and high gradient, which in turn require very high frequency high power rf sources. Recent development work in W-band accelerating techniques has spurred the development of a high-power W-band source. Axisymmetric sources suffer from fundamental power output limitations (P{sub sat} {approx} {lambda}{sup 2}) brought on by the conflicting requirements of small beam sizes and high beam current. The sheet beam klystron allows for an increase in beam current without substantial increase in the beam current density, allowing for reduced cathode current densities and focusing field strengths. Initial simulations of a 20:1 aspect ratio sheet beam/cavity interaction using the 3 dimensional particle-in-cell code Magic3D have demonstrated a 35% beam-power to RF power extraction efficiency. Calculational work and numerical simulations leading to a prototype W-band sheet beam klystron will be presented, together with preliminary cold test structure studies of a proposed RF cavity geometry.

  3. W-band sheet beam klystron simulation

    SciTech Connect (OSTI)

    Colby, E.R.; Caryotakis, G.; Fowkes, W.R. [Stanford Linear Accelerator Center, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States); Smithe, D.N. [Mission Research Corporation, 8560 Cinderbed Road, Ste. 700, Newington, Virginia 22122 (United States)

    1999-05-01

    With the development of ever higher energy particle accelerators comes the need for compactness and high gradient, which in turn require very high frequency high power rf sources. Recent development work in W-band accelerating techniques has spurred the development of a high-power W-band source. Axisymmetric sources suffer from fundamental power output limitations (P{sub sat}{approximately}{lambda}{sup 2}) brought on by the conflicting requirements of small beam sizes and high beam current. The sheet beam klystron allows for an increase in beam current without substantial increase in the beam current density, allowing for reduced cathode current densities and focussing field strengths. Initial simulations of a 20:1 aspect ratio sheet beam/cavity interaction using the 3 dimensional particle-in-cell code Magic3D have demonstrated a 35{percent} beam-power to RF power extraction efficiency. Calculational work and numerical simulations leading to a prototype W-band sheet beam klystron will be presented, together with preliminary cold test structure studies of a proposed RF cavity geometry. {copyright} {ital 1999 American Institute of Physics.}

  4. 3-D simulations of multiple beam klystrons

    SciTech Connect (OSTI)

    Smithe, David N.; Bettenhausen, Mike; Ludeking, Larry; Caryotakis, G.; Sprehn, Daryl; Scheitrum, Glenn [Mission Research Corporation, 8560 Cinderbed Rd., Suite 700, Newington, Virginia 22122 (United States); Stanford Linear Accelerator Center, 2575 Sand Hill Rd., Menlo Park, California 94025 (United States)

    1999-05-07

    The MAGIC3D simulation code is being used to assess the multi-dimensional physics issues relating to the design and operation of multiple beam klystrons. Investigations, to date, include a detailed study of the mode structure of the cavities in the 19-beam hexagonally packed geometry and a study of the velocity spread caused by the cavity mode's field profile. Some attempts to minimize this effect are investigated. Additional simulations have provided quantification of the beam loading Q in a dual input cavity, and optimization of a dual output cavity. An important goal of the simulations is an accurate picture of beam transport along the length of the MBK. We have quantified the magnitude and spatial variation of the beam-line space charge interactions within a cavity gap. Present simulations have demonstrated the transport of the beam through three cavities (the present limits of our simulation size) without difficulty; additional length simulations are expected. We have also examined unbalanced beam-line scenarios, e.g., one beam-line suppressed, and find little disturbance to the transport in individual cavity tests, with results for multiple cavity transport expected.

  5. Polymer surface treatment with particle beams

    DOE Patents [OSTI]

    Stinnett, Regan W. (1033 Tramway La. NE., Albuquerque, NM 87122); VanDevender, J. Pace (7604 Lamplighter NE., Albuquerque, NM 87109)

    1999-01-01

    A polymer surface and near surface treatment process produced by irradiation with high energy particle beams. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications.

  6. A TOMOGRAPHIC TECHNIQUE FOR MAGNETIZED BEAM MATCHING.

    SciTech Connect (OSTI)

    MONTAG,C.ET AL.

    2004-07-05

    To maintain low electron beam temperatures in the proposed RHIC electron cooler, careful matching of the magnetized beam from the source to the cooler solenoid is mandatory. We propose a tomographic technique to diagnose matching conditions. First simulation results will be presented.

  7. Aerodynamic beam generator for large particles

    DOE Patents [OSTI]

    Brockmann, John E. (Albuquerque, NM); Torczynski, John R. (Albuquerque, NM); Dykhuizen, Ronald C. (Albuquerque, NM); Neiser, Richard A. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    2002-01-01

    A new type of aerodynamic particle beam generator is disclosed. This generator produces a tightly focused beam of large material particles at velocities ranging from a few feet per second to supersonic speeds, depending on the exact configuration and operating conditions. Such generators are of particular interest for use in additive fabrication techniques.

  8. Polymer surface treatment with particle beams

    DOE Patents [OSTI]

    Stinnett, R.W.; VanDevender, J.P.

    1999-05-04

    A polymer surface and near surface treatment process produced by irradiation with high energy particle beams is disclosed. The process is preferably implemented with pulsed ion beams. The process alters the chemical and mechanical properties of the polymer surface in a manner useful for a wide range of commercial applications. 16 figs.

  9. Modulator considerations for beam chopping in the low energy beam transport at the SSC Laboratory

    SciTech Connect (OSTI)

    Anderson, D.; Pappas, G.

    1991-06-01

    Beam chopping in the low energy transport line at the Superconducting Super Collider Laboratory is accomplished using an electrostatic deflection system. LINAC requirements dictate the design of two modulators operating at 10 Hz with rise and fall times (as measured from approximately 10--99%) of {approximately}100 ns. Design of the first pulser, normally at 10 kV and pulsed to ground potential, utilizes a transformer-coupled diode-clamped solid state circuit to achieve the 2--35 {mu}s pulse width range required. The second pulser, which pulses from ground to approximately 7 kV, relies on a series vacuum tube circuit. The current designs, as well as recent test results and other circuit topologies considered, will be presented. 6 refs.

  10. Microwave accelerator E-beam pumped laser

    DOE Patents [OSTI]

    Brau, Charles A.; Stein, William E.; Rockwood, Stephen D.

    1980-01-01

    A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

  11. Strong-strong beam-beam simulation using a green function approach

    SciTech Connect (OSTI)

    Qiang, Ji; Furman, Miguel A.; Ryne, Robert D.

    2002-09-08

    In this paper we present a news approach, based on a shifted Green function, to evaluate the electromagnetic field in a simulation of colliding beams. Unlike a conventional particle-mesh code, we use a method in which the computational mesh covers only the largest of the two colliding beams. This allows us to study long-range parasitic collisions accurately and efficiently. We have implemented this algorithm in a new parallel strong-strong beam-beam simulation code. As an application, we present a study of a beam sweeping scheme for the LBNL luminosity monitor of the Large Hadron Collider.

  12. First Beam Waist Measurements in the Final Focus Beam Line at the KEK

    Office of Scientific and Technical Information (OSTI)

    Accelerator Test Facility (Journal Article) | SciTech Connect First Beam Waist Measurements in the Final Focus Beam Line at the KEK Accelerator Test Facility Citation Details In-Document Search Title: First Beam Waist Measurements in the Final Focus Beam Line at the KEK Accelerator Test Facility The ATF2 project is the final focus system prototype for the ILC and CLIC linear collider projects, with a purpose to reach a 37 nm vertical beam size at the interaction point using compact optics

  13. Intense Muon Beams for Experiments at Project X

    SciTech Connect (OSTI)

    C.M. Ankenbrandt, R.P. Johnson, C. Y. Yoshikawa, V.S. Kashikhin, D.V. Neuffer, J. Miller, R.A. Rimmer

    2011-03-01

    A coherent approach for providing muon beams to several experiments for the intensity-frontier program at Project X is described. Concepts developed for the front end of a muon collider/neutrino factory facility, such as phase rotation and ionization cooling, are applied, but with significant differences. High-intensity experiments typically require high-duty-factor beams pulsed at a time interval commensurate with the muon lifetime. It is challenging to provide large RF voltages at high duty factor, especially in the presence of intense radiation and strong magnetic fields, which may preclude the use of superconducting RF cavities. As an alternative, cavities made of materials such as ultra-pure Al and Be, which become very good but not super conductors at cryogenic temperatures, can be used.

  14. Volume Reflection of a Proton Beam in a Bent Crystal

    SciTech Connect (OSTI)

    Ivanov, Yu. M.; Petrunin, A. A.; Skorobogatov, V. V.; Gavrikov, Yu. A.; Gelamkov, A. V.; Lapina, L. P.; Schetkovsky, A. I.; Vavilov, S. A.; Baranov, V. I.; Chesnokov, Yu. A.; Afonin, A. G.; Baranov, V. T.; Chepegin, V. N.; Guidi, V.; Vomiero, A.

    2006-10-06

    Volume reflection predicted in the mid-1980s by Taratin and Vorobiev has been observed for the first time in the interactions of a 70 GeV proton beam with a short bent crystal. Incident protons deviate from convex atomic planes in the bulk of the crystal as a result of coherent interaction with bent lattice around the tangency point of particle trajectory with a curved atomic plane. The deflection angle 2{theta}{sub R} was found to be (39.5{+-}2.0) {mu}rad, or (1.65{+-}0.08){theta}{sub c} in terms of the critical angle for channeling. The process has a large probability with respect to channeling and takes place in the angular range equal to the bend angle of atomic planes. It could possibly open new fields of application of crystals in high-energy particle beam optics.

  15. Weak-strong simulation on head-on beam-beam compensation in the RHIC

    SciTech Connect (OSTI)

    Luo,Y.; Fischer, W.; McIntosh, E.; Robert-Demolaize, G.; Abreu, N.; Beebe-Wang, J.; Montag, C.

    2009-05-04

    In the Relativistic Heavy Ion Collider (RHIC) beams collide in the two interaction points IP6 and IP8. To further increase the bunch intensity above 2 x 10{sup 11} or further reduce the transverse emittance in polarized proton operation, there will not be enough tune space between the current working area [2/3, 7/10] to hold the beam-beam generated tune spread. We proposed a low energy DC electron beam (e-lens) with similar Gaussian transverse profiles to collide with the proton beam at IP10. Early studies have shown that e-lens does reduce the proton-proton beam-beam tune spread. In this article, we carried out numerical simulation to investigate the effects of the head-on beam-beam effect on the proton's colliding beam lifetime and emittance growth. The preliminary results including scans of compensation strength, phase advances between IP8 and IP10, electron beam transverse sizes are presented. In these studies, the particle loss in the multi-particle simulation is used for the comparison between different conditions.

  16. Optics of ion beams for the neutral beam injection system on HL-2A Tokamak

    SciTech Connect (OSTI)

    Zou, G. Q.; Lei, G. J.; Cao, J. Y.; Duan, X. R.

    2012-07-15

    The ion beam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ion beam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ion beam optics, the application of a small pre-acceleration voltage ({approx}100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ion beam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.

  17. Ion-beam apparatus and method for analyzing and controlling integrated circuits

    DOE Patents [OSTI]

    Campbell, A.N.; Soden, J.M.

    1998-12-01

    An ion-beam apparatus and method for analyzing and controlling integrated circuits are disclosed. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal. 4 figs.

  18. Ion-beam apparatus and method for analyzing and controlling integrated circuits

    DOE Patents [OSTI]

    Campbell, Ann N. (Albuquerque, NM); Soden, Jerry M. (Placitas, NM)

    1998-01-01

    An ion-beam apparatus and method for analyzing and controlling integrated circuits. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal.

  19. Role Model and Activity Volunteers Needed to Help with BEAMS...

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

    Model and Activity Volunteers Needed to Help with BEAMS - Jefferson Lab's Science and Math Outreach Program for Students B.E.A.M.S. BEAMS students learn about energy transfer,...

  20. Electrostatic wire for stabilizing a charged particle beam

    DOE Patents [OSTI]

    Prono, Daniel S. (Livermore, CA); Caporaso, George J. (Livermore, CA); Briggs, Richard J. (Livermore, CA)

    1985-01-01

    In combination with a charged particle beam generator and accelerator, apparatus and method are provided for stabilizing a beam of electrically charged particles. A guiding means, disposed within the particle beam, has an electric charge induced upon it by the charged particle beam. Because the sign of the electric charge on the guiding means and the sign of the particle beam are opposite, the particles are attracted toward and cluster around the guiding means to thereby stabilize the particle beam as it travels.

  1. System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)

    DOE Patents [OSTI]

    Skupsky, S.; Kessler, T.J.; Short, R.W.; Craxton, S.; Letzring, S.A.; Soures, J.

    1991-09-10

    In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies (''colors'') cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers. 8 figures.

  2. Prediction of Material Thermal Properties and Beam-Particle Interactio...

    Office of Scientific and Technical Information (OSTI)

    and Beam-Particle Interaction at Meso-Scale during Electron Beam Additive Manufacturing Citation Details In-Document Search Title: Prediction of Material Thermal...

  3. Design of a Subnanometer Resolution Beam Position Monitor for...

    Office of Scientific and Technical Information (OSTI)

    Design of a Subnanometer Resolution Beam Position Monitor for Dielectric Laser Accelerators Citation Details In-Document Search Title: Design of a Subnanometer Resolution Beam...

  4. Beam Loading by Distributed Injection of Electrons in a Plasma...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Beam Loading by Distributed Injection of Electrons in a Plasma Wakefield Accelerator Citation Details In-Document Search Title: Beam Loading by Distributed...

  5. Inhomogeneity smoothing using density valley formed by ion beam...

    Office of Scientific and Technical Information (OSTI)

    deposition in an ion-beam inertial confinement fusion pellets by numerical simulation. ... dominated beam physics for heavy ion fusion, Saitama (Japan), 10-12 Dec 1998; Other ...

  6. SLAC National Accelerator Laboratory FACET & TEST BEAM FACILITIES...

    Office of Scientific and Technical Information (OSTI)

    Laboratory FACET & TEST BEAM FACILITIES PROPOSAL Citation Details In-Document Search Title: SLAC National Accelerator Laboratory FACET & TEST BEAM FACILITIES PROPOSAL ...

  7. Design of a Subnanometer Resolution Beam Position Monitor for...

    Office of Scientific and Technical Information (OSTI)

    Design of a Subnanometer Resolution Beam Position Monitor for Dielectric Laser Accelerators Citation Details In-Document Search Title: Design of a Subnanometer Resolution Beam ...

  8. Progress on optimization of the nonlinear beam dynamics in the...

    Office of Scientific and Technical Information (OSTI)

    strong beam focusing unavoidably causes large chromatic effects such as chromatic tune spread and beam smear at the IP, which need to be compensated. This paper reports recent...

  9. Meso-Scale during Electron Beam Additive Manufacturing Chen,...

    Office of Scientific and Technical Information (OSTI)

    Thermal Properties and Beam-Particle Interaction at Meso-Scale during Electron Beam Additive Manufacturing Chen, Jian ORNL ORNL; Zheng, Lili ORNL ORNL; Feng, Zhili...

  10. PERSONNEL PROTECTION SYSTEM UPGRADE FOR THE LCLS ELECTRON BEAM...

    Office of Scientific and Technical Information (OSTI)

    PERSONNEL PROTECTION SYSTEM UPGRADE FOR THE LCLS ELECTRON BEAM LINAC Citation Details In-Document Search Title: PERSONNEL PROTECTION SYSTEM UPGRADE FOR THE LCLS ELECTRON BEAM LINAC...

  11. Ion beam assisted deposition of thermal barrier coatings

    DOE Patents [OSTI]

    Youchison, Dennis L. (Albuquerque, NM); McDonald, Jimmie M. (Albuquerque, NM); Lutz, Thomas J. (Albuquerque, NM); Gallis, Michail A. (Albuquerque, NM)

    2010-11-23

    Methods and apparatus for depositing thermal barrier coatings on gas turbine blades and vanes using Electron Beam Physical Vapor Deposition (EBPVD) combined with Ion Beam Assisted Deposition (IBAD).

  12. 43 PARTICLE ACCELERATORS; ELECTRON GUNS; BEAM EMITTANCE; CHARGE

    Office of Scientific and Technical Information (OSTI)

    SPACE 430200* -- Particle Accelerators-- Beam Dynamics, Field Calculations, & Ion Optics The evolution of the electron-beam phase space distribution in laser-driven rf guns is...

  13. Online optimization of storage ring nonlinear beam dynamics ...

    Office of Scientific and Technical Information (OSTI)

    Online optimization of storage ring nonlinear beam dynamics Citation Details In-Document Search Title: Online optimization of storage ring nonlinear beam dynamics Authors: Huang,...

  14. Online optimization of storage ring nonlinear beam dynamics ...

    Office of Scientific and Technical Information (OSTI)

    Online optimization of storage ring nonlinear beam dynamics Citation Details In-Document Search Title: Online optimization of storage ring nonlinear beam dynamics You are...

  15. Sandia Energy - National Solar Thermal Testing Facility Beam...

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

    National Solar Thermal Testing Facility Beam Profiling Home Renewable Energy News Concentrating Solar Power Solar National Solar Thermal Testing Facility Beam Profiling Previous...

  16. First Beam Measurements with the LHC Synchrotron Light Monitors...

    Office of Scientific and Technical Information (OSTI)

    Title: First Beam Measurements with the LHC Synchrotron Light Monitors The continuous monitoring of the transverse sizes of the beams in the Large Hadron Collider (LHC) relies on ...

  17. Transverse beam dynamics in plasma-based linacs (Conference)...

    Office of Scientific and Technical Information (OSTI)

    accelerator by a uniform focusing channel. The transverse beam sizes and a basic offset tolerance are calculated, finding that sub-micron beams must be transported with even...

  18. Measuring Tiny Waves with High Power Particle Beams | Princeton...

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

    Measuring Tiny Waves with High Power Particle Beams American Fusion News Category: U.S. Universities Link: Measuring Tiny Waves with High Power Particle Beams...

  19. Design and performance of the traveling-wave beam chopper for the SSRL injector

    SciTech Connect (OSTI)

    Borland, M.; Weaver, J.N.; Baltay, M.; Emery, L.; Fisher, A.S.; Golceff, P.; Hettel, R.; Morales, H.; Sebek, J.; Wiedemann, H.; Youngman, B. . Stanford Synchrotron Radiation Lab.); Anderson, R. ); Miller, R.H. )

    1991-05-01

    A pulsed, split-parallel plate chopper has been designed built, and installed as part of the preinjector of the SSRL Injector. Its function is to allow the linear accelerator three consecutive S-band bunches from the long bunch train provided by a RF gun. A permanent magnet deflector (PMD) at the chopper entrance deflects the beam into an absorber when the chopper pulse is off. The beam is swept across a pair of slits at the beam output end when a 7 kV, 10-ns rise-time pulse passes in the opposite direction through the 75 {Omega} stripline formed by the deflecting plates. Bunches exiting the slits have their trajectories corrected by another PMD, and enter the linac. Beam tests demonstrate that the chopper functions as expected. 9 refs., 5 figs.

  20. Using E-beam Mapping to Detect Coil Misalignment in NCSX

    SciTech Connect (OSTI)

    Fredrickson, E.; Georgiyevskiy, A.; Rudakov, V.; Zarnstorff, M. C.

    2005-10-18

    Following assembly of the NCSX device, a program of e-beam mapping experiments is planned to validate the accuracy of the construction and assembly of the NCSX coil systems. To aid in the development of requirements for the e-beam mapping hardware and machine requirements, simulations of the e-beam mapping experiments, including various coil misalignments, have been done. The magnetic flux surface configuration was constructed using a numerical code, based on the Biot-Savart law, to calculate the magnetic field components and trace the field line trajectory many times around the torus. Magnetic surfaces are then mapped by recording the field line intersections with toroidal cross-sections of the magnetic system, much as in an actual e-beam mapping experiment.

  1. Intense steady state electron beam generator

    DOE Patents [OSTI]

    Hershcovitch, A.; Kovarik, V.J.; Prelec, K.

    1990-07-17

    An intense, steady state, low emittance electron beam generator is formed by operating a hollow cathode discharge plasma source at critical levels in combination with an extraction electrode and a target electrode that are operable to extract a beam of fast primary electrons from the plasma source through a negatively biased grid that is critically operated to repel bulk electrons toward the plasma source while allowing the fast primary electrons to move toward the target in the desired beam that can be successfully transported for relatively large distances, such as one or more meters away from the plasma source. 2 figs.

  2. Energy-beam-driven rapid fabrication system

    DOE Patents [OSTI]

    Keicher, David M. (Albuquerque, NM); Atwood, Clinton L. (Albuquerque, NM); Greene, Donald L. (Corrales, NM); Griffith, Michelle L. (Albuquerque, NM); Harwell, Lane D. (Albuquerque, NM); Jeantette, Francisco P. (Albuquerque, NM); Romero, Joseph A. (Albuquerque, NM); Schanwald, Lee P. (Albuquerque, NM); Schmale, David T. (Albuquerque, NM)

    2002-01-01

    An energy beam driven rapid fabrication system, in which an energy beam strikes a growth surface to form a molten puddle thereon. Feed powder is then injected into the molten puddle from a converging flow of feed powder. A portion of the feed powder becomes incorporated into the molten puddle, forcing some of the puddle contents to freeze on the growth surface, thereby adding an additional layer of material. By scanning the energy beam and the converging flow of feed powder across the growth surface, complex three-dimensional shapes can be formed, ready or nearly ready for use. Nearly any class of material can be fabricated using this system.

  3. Trigger probe for determining the orientation of the power distribution of an electron beam

    DOE Patents [OSTI]

    Elmer, John W. (Danville, CA); Palmer, Todd A. (Livermore, CA); Teruya, Alan T. (Livermore, CA)

    2007-07-17

    The present invention relates to a probe for determining the orientation of electron beams being profiled. To accurately time the location of an electron beam, the probe is designed to accept electrons from only a narrowly defined area. The signal produced from the probe is then used as a timing or triggering fiducial for an operably coupled data acquisition system. Such an arrangement eliminates changes in slit geometry, an additional signal feedthrough in the wall of a welding chamber and a second timing or triggering channel on a data acquisition system. As a result, the present invention improves the accuracy of the resulting data by minimizing the adverse effects of current slit triggering methods so as to accurately reconstruct electron or ion beams.

  4. Low Beam Voltage, 10 MW, L-Band Cluster Klystron

    SciTech Connect (OSTI)

    Teryaev, V.; Yakovlev, V.P.; Kazakov, S.; Hirshfield, J.L.; /Yale U. /Omega-P, New Haven

    2009-05-01

    Conceptual design of a multi-beam klystron (MBK) for possible ILC and Project X applications is presented. The chief distinction between this MBK design and existing 10-MW MBK's is the low operating voltage of 60 kV. There are at least four compelling reasons that justify development at this time of a low-voltage MBK, namely (1) no pulse transformer; (2) no oil tank for high-voltage components and for the tube socket; (3) no high-voltage cables; and (4) modulator would be a compact 60-kV IGBT switching circuit. The proposed klystron consists of four clusters containing six beams each. The tube has common input and output cavities for all 24 beams, and individual gain cavities for each cluster. A closely related optional configuration, also for a 10 MW tube, would involve four totally independent cavity clusters with four independent input cavities and four 2.5 MW output ports, all within a common magnetic circuit. This option has appeal because the output waveguides would not require a controlled atmosphere, and because it would be easier to achieve phase and amplitude stability as required in individual SC accelerator cavities.

  5. 14th international symposium on molecular beams

    SciTech Connect (OSTI)

    Not Available

    1992-09-01

    This report discusses research being conducted with molecular beams. The general topic areas are as follows: Clusters I; reaction dynamics; atomic and molecular spectroscopy; clusters II; new techniques; photodissociation & dynamics; and surfaces.

  6. 14th international symposium on molecular beams

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

    This report discusses research being conducted with molecular beams. The general topic areas are as follows: Clusters I; reaction dynamics; atomic and molecular spectroscopy; clusters II; new techniques; photodissociation dynamics; and surfaces.

  7. Yuan T. Lee's Crossed Molecular Beam Experiment

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

    The above illustration was drawn by Professor Yuan T. Lee, who shared the 1986 Nobel Prize in Chemistry. It shows the design for his crossed molecular beam experiment described in ...

  8. Solar Power Beaming: From Space to Earth

    SciTech Connect (OSTI)

    Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

    2009-04-14

    Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

  9. Compact high precision adjustable beam defining aperture

    DOE Patents [OSTI]

    Morton, Simon A; Dickert, Jeffrey

    2013-07-02

    The present invention provides an adjustable aperture for limiting the dimension of a beam of energy. In an exemplary embodiment, the aperture includes (1) at least one piezoelectric bender, where a fixed end of the bender is attached to a common support structure via a first attachment and where a movable end of the bender is movable in response to an actuating voltage applied to the bender and (2) at least one blade attached to the movable end of the bender via a second attachment such that the blade is capable of impinging upon the beam. In an exemplary embodiment, the beam of energy is electromagnetic radiation. In an exemplary embodiment, the beam of energy is X-rays.

  10. SolBeam Inc | Open Energy Information

    Open Energy Info (EERE)

    California Zip: 92677 Product: California-based startup developing concentrator photovoltaics. References: SolBeam Inc1 This article is a stub. You can help OpenEI by...

  11. Laser beam centering and pointing system

    DOE Patents [OSTI]

    Rushford, Michael Charles

    2015-01-13

    An optical instrument aligns an optical beam without the need for physical intervention of the instrument within the apparatus or platforms from which the trajectory of the beam to be ascertained. The alignment apparatus and method enable the desired function to be realized without the placement of physical apertures or sensors directly in the path of the beam through the system whose spatial position and slope is to be sought. An image plane provides the observer with a pair of well-defined images that are indicative of the beam centering and pointing alignment parameters. The optical alignment can be realized without the need for referencing to an external or fixed set of coordinates or fiducials. The instrument can therefore service situations where adverse environments would otherwise prohibit the use of such instruments, including regions of high radiation, high temperature, vacuum and/or cryogenic atmospheres.

  12. Pseudo ribbon metal ion beam source

    SciTech Connect (OSTI)

    Stepanov, Igor B. Ryabchikov, Alexander I.; Sivin, Denis O.; Verigin, Dan A.

    2014-02-15

    The paper describes high broad metal ion source based on dc macroparticle filtered vacuum arc plasma generation with the dc ion-beam extraction. The possibility of formation of pseudo ribbon beam of metal ions with the parameters: ion beam length 0.6 m, ion current up to 0.2 A, accelerating voltage 40 kV, and ion energy up to 160 kV has been demonstrated. The pseudo ribbon ion beam is formed from dc vacuum arc plasma. The results of investigation of the vacuum arc evaporator ion-emission properties are presented. The influence of magnetic field strength near the cathode surface on the arc spot movement and ion-emission properties of vacuum-arc discharge for different cathode materials are determined. It was shown that vacuum-arc discharge stability can be reached when the magnetic field strength ranges from 40 to 70 G on the cathode surface.

  13. Optical chirped beam amplification and propagation

    DOE Patents [OSTI]

    Barty, Christopher P.

    2004-10-12

    A short pulse laser system uses dispersive optics in a chirped-beam amplification architecture to produce high peak power pulses and high peak intensities without the potential for intensity dependent damage to downstream optical components after amplification.

  14. Flow-through ion beam source

    DOE Patents [OSTI]

    Springer, Robert W.

    1997-01-01

    A method and an apparatus for forming a charge neutral ion beam which is useful in producing thin films of material on electrically conductive or non-conductive substrates are provided.

  15. Flow-through ion beam source

    DOE Patents [OSTI]

    Springer, R.W.

    1997-02-11

    A method and an apparatus for forming a charge neutral ion beam which is useful in producing thin films of material on electrically conductive or non-conductive substrates are provided. 4 figs.

  16. The Electron Beam Ion Source (EBIS)

    ScienceCinema (OSTI)

    Brookhaven Lab

    2010-01-08

    Brookhaven National Lab has successfully developed a new pre-injector system, called the Electron Beam Ion Source, for the Relativistic Heavy Ion Collider (RHIC) and NASA Space Radiation Laboratory science programs. The first of several planned improvemen

  17. Doublet III neutral beam power system

    SciTech Connect (OSTI)

    Nerem, A.; Beal, J.W.; Colleraine, A.P.; LeVine, F.H.; Pipkins, J.F.; Remsen, D.B. Jr.; Tooker, J.F.; Varga, H.J.; Franck, J.V.

    1981-01-01

    The Doublet III neutral beam power system supplies pulsed power to the neutral beam injectors for plasma heating experiments on the Doublet III tokamak. The power supply system is connected to an ion source where the power is converted to an 80 kV, 80A, 0.5 sec beam of hydrogen ions at maximum power output. These energetic ions undergo partial neutralization via charge exchange in the beamline. The energetic neutral hydrogen atoms pass through the Doublet III toroidal and poloidal magnet fields and deposit their energy in the confined plasma. The unneutralized ions are deflected into a water-cooled dump. The entire system is interfaced through the neutral beam computer instrumentation and control system.

  18. Scrap uranium recycling via electron beam melting

    SciTech Connect (OSTI)

    McKoon, R.

    1993-11-01

    A program is underway at the Lawrence Livermore National Laboratory (LLNL) to recycle scrap uranium metal. Currently, much of the material from forging and machining processes is considered radioactive waste and is disposed of by oxidation and encapsulation at significant cost. In the recycling process, uranium and uranium alloys in various forms will be processed by electron beam melting and continuously cast into ingots meeting applicable specifications for virgin material. Existing vacuum processing facilities at LLNL are in compliance with all current federal and state environmental, safety and health regulations for the electron beam melting and vaporization of uranium metal. One of these facilities has been retrofitted with an auxiliary electron beam gun system, water-cooled hearth, crucible and ingot puller to create an electron beam melt furnace. In this furnace, basic process R&D on uranium recycling will be performed with the goal of eventual transfer of this technology to a production facility.

  19. Results of head-on beam-beam compensation studies at the Tevatron

    SciTech Connect (OSTI)

    Valishev, A.; Stancari, G.; /Fermilab

    2011-03-01

    At the Tevatron collider, we studied the feasibility of suppressing the antiproton head-on beam-beamtune spread using a magnetically confined 5-keV electron beam with Gaussian transverse profile overlapping with the circulating beam. When electron cooling of antiprotons is applied in regular Tevatron operations, the head-on beam-beam effect on antiprotons is small. Therefore, we first focused on the operational aspects, such as beam alignment and stability, and on fundamental observations of tune shifts, tune spreads, lifetimes, and emittances. We also attempted two special collider stores with only 3 proton bunches colliding with 3 antiproton bunches, to suppress long-range forces and enhance head-on effects. We present here the results of this study and a comparison between numerical simulations and observations, in view of the planned application of this compensation concept to RHIC.

  20. Shielded beam delivery apparatus and method

    DOE Patents [OSTI]

    Hershcovitch, Ady; Montano, Rory Dominick

    2006-07-11

    An apparatus includes a plasma generator aligned with a beam generator for producing a plasma to shield an energized beam. An electrode is coaxially aligned with the plasma generator and followed in turn by a vortex generator coaxially aligned with the electrode. A target is spaced from the vortex generator inside a fluid environment. The electrode is electrically biased relative to the electrically grounded target for driving the plasma toward the target inside a vortex shield.

  1. Probing Organic Transistors with Infrared Beams

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

    Probing Organic Transistors with Infrared Beams Probing Organic Transistors with Infrared Beams Print Wednesday, 26 July 2006 00:00 Silicon-based transistors are well-understood, basic components of contemporary electronic technology. In contrast, there is growing need for the development of electronic devices based on organic polymer materials. Organic field-effect transistors (FETs) are ideal for special applications that require large areas, light weight, and structural flexibility. They also

  2. CSR Impedance for Non-Ultrarelativistic Beams

    SciTech Connect (OSTI)

    Li, Rui; Tsai, Cheng Y.

    2015-09-01

    For the analysis of the coherent synchrotron radiation (CSR) induced microbunching gain in the low energy regime, such as when a high-brightness electron beam is transported through a low-energy merger in an energy-recovery linac (ERL) design, it is necessary to extend the CSR impedance expression in the ultrarelativistic limit to the non-ultrarelativistic regime. This paper presents our analysis of CSR impedance for general beam energies.

  3. Dudley Herschbach: Chemical Reactions and Molecular Beams

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

    Dudley Herschbach: Chemical Reactions and Molecular Beams Resources with Additional Information Dudley Herschbach Courtesy of Texas A&M University As a co-recipient of the 1986 Nobel Prize in Chemistry, 'Dudley Herschbach was cited for "providing a much more detailed understanding of how chemical reactions take place". Using molecular beams, he studied elementary reactions such as K + CH3I and K + Br2, where it became possible to correlate reaction dynamics with the electronic

  4. Ion beam processing of advanced electronic materials

    SciTech Connect (OSTI)

    Cheung, N.W.; Marwick, A.D.; Roberto, J.B. (eds.) (California Univ., Berkeley, CA (USA); International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center; Oak Ridge National Lab., TN (USA))

    1989-01-01

    This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

  5. Science with Beams of Radioactive Isotopes

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

    Pacifichem 2015 Pacifichem 2015 The International Chemical Congress of Pacific Basin Societies Science with Beams of Radioactive Isotopes (# 340) Honolulu, Hawaii, USA December 15-20, 2015 Science with Beams of Radioactive Isotopes (# 340) All of the elements that make up the periodic chart have been created from nuclear reactions. Many of the stable nuclei in the universe are daughters of unstable isotopes, and their true origin lies in the stellar reactions of these radioactive isotopes. Thus

  6. Decreasing Beam Auto Tuning Interruption Events with In-Situ Chemical Cleaning on Axcelis GSD

    SciTech Connect (OSTI)

    Fuchs, Dieter; Spreitzer, Stefan; Vogl, Josef [Infineon Technologies AG., Wernerwerkstr.2, 93049 Regensburg (Germany); Bishop, Steve; Eldridge, David; Kaim, Robert [ATMI Inc., 7 Commerce Drive, Danbury, CT 06810 (United States)

    2008-11-03

    Ion beam auto tuning time and success rate are often major factors in the utilization and productivity of ion implanters. Tuning software frequently fails to meet specified setup times or recipe parameters, causing production stoppages and requiring manual intervention. Build-up of conductive deposits in the arc chamber and extraction gap can be one of the main causes of auto tuning problems. The deposits cause glitching and ion beam instabilities, which lead to errors in the software optimization routines. Infineon Regensburg has been testing use of XeF{sub 2}, an in-situ chemical cleaning reagent, with positive results in reducing auto tuning interruption events.

  7. A laser-wire beam-energy and beam-profile monitor at the BNL linac

    SciTech Connect (OSTI)

    Connolly, R.; Degen, C.; DeSanto, L.; Meng, W.; Michnoff, R.; Minty, M.; Nayak, S.

    2011-03-28

    In 2009 a beam-energy monitor was installed in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. This device measures the energies of electrons stripped from the 40mA H{sup -} beam by background gas. Electrons are stripped by the 2.0x10{sup -7}torr residual gas at a rate of {approx}1.5x10{sup -8}/cm. Since beam electrons have the same velocities as beam protons, the beam proton energy is deduced by multiplying the electron energy by m{sub p}/m{sub e}=1836. A 183.6MeV H{sup -} beam produces 100keV electrons. In 2010 we installed an optics plates containing a laser and scanning optics to add beam-profile measurement capability via photodetachment. Our 100mJ/pulse, Q-switched laser neutralizes 70% of the beam during its 10ns pulse. This paper describes the upgrades to the detector and gives profile and energy measurements.

  8. Coherent beam-beam effects observation and mitigation at the RHIC collider

    SciTech Connect (OSTI)

    White S.; Fischer, W.; Luo, Y.

    2012-05-20

    In polarized proton operation in RHIC coherent beam-beam modes are routinely observed with beam transfer function measurements in the vertical plane. With the existence of coherent modes a larger space is required in the tune diagram than without them and stable conditions can be compromised for operation with high intensity beams as foreseen for future luminosity upgrades. We report on experiments and simulations carried out to understand the existence of coherent modes in the vertical plane and their absence in the horizontal plane, and investigate possible mitigation strategies.

  9. The effects of betatron phase advances on beam-beam and its compensation in RHIC

    SciTech Connect (OSTI)

    Luo, Y.; Fischer, W.; Gu, X.; Tepikian, S.; Trbojevic, D.

    2011-03-28

    In this article we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used in this study. We also scan the betatron phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

  10. Optimum focusing of Gaussian laser beams: Beam waist shift in spot size minimization

    SciTech Connect (OSTI)

    Li, Y.; Katz, J. )

    1994-04-01

    Optimum focusing of Gaussian laser beams is first discussed by Dickson, who described the change in beam radius under the effect of focusing system parameters. The purpose of this study is to present a formulation for calculating the waist shift under various optimum conditions. Because the variations of beam waist can be measured directly, the waist shift in a focused Gaussian beam is a more practical parameter than the movement of the intensity maximum that is the subject for investigators of the well-known focal shift problem.

  11. Laboratory Measurements of Electrostatic Solitary Structures Generated by Beam Injection

    SciTech Connect (OSTI)

    Lefebvre, Bertrand; Chen, Li-Jen; Gekelman, Walter; Pribyl, Patrick; Vincena, Stephen; Kintner, Paul; Pickett, Jolene; Chiang, Franklin; Judy, Jack

    2010-09-10

    Electrostatic solitary structures are generated by injection of a suprathermal electron beam parallel to the magnetic field in a laboratory plasma. Electric microprobes with tips smaller than the Debye length ({lambda}{sub De}) enabled the measurement of positive potential pulses with half-widths 4 to 25{lambda}{sub De} and velocities 1 to 3 times the background electron thermal speed. Nonlinear wave packets of similar velocities and scales are also observed, indicating that the two descend from the same mode which is consistent with the electrostatic whistler mode and result from an instability likely to be driven by field-aligned currents.

  12. Use of radial self-field geometry for intense pulsed ion beam generation above 6 MeV on Hermes III.

    SciTech Connect (OSTI)

    Renk, Timothy Jerome; Harper-Slaboszewicz, Victor Jozef; Ginn, William Craig; Mikkelson, Kenneth A.; Schall, Michael; Cooper, Gary Wayne

    2012-12-01

    We investigate the generation and propagation of intense pulsed ion beams at the 6 MeV level and above using the Hermes III facility at Sandia National Laboratories. While high-power ion beams have previously been produced using Hermes III, we have conducted systematic studies of several ion diode geometries for the purpose of maximizing focused ion energy for a number of applications. A self-field axial-gap diode of the pinch reflex type and operated in positive polarity yielded beam power below predicted levels. This is ascribed both to power flow losses of unknown origin upstream of the diode load in Hermes positive polarity operation, and to anomalies in beam focusing in this configuration. A change to a radial self-field geometry and negative polarity operation resulted in greatly increased beam voltage (> 6 MeV) and estimated ion current. A comprehensive diagnostic set was developed to characterize beam performance, including both time-dependent and time-integrated measurements of local and total beam power. A substantial high-energy ion population was identified propagating in reverse direction, i.e. from the back side of the anode in the electron beam dump. While significant progress was made in increasing beam power, further improvements in assessing the beam focusing envelope will be required before ultimate ion generation efficiency with this geometry can be completely determined.

  13. Simultaneous multi-beam planar array IR (pair) spectroscopy

    DOE Patents [OSTI]

    Elmore, Douglas L.; Rabolt, John F.; Tsao, Mei-Wei

    2005-09-13

    An apparatus and method capable of providing spatially multiplexed IR spectral information simultaneously in real-time for multiple samples or multiple spatial areas of one sample using IR absorption phenomena requires no moving parts or Fourier Transform during operation, and self-compensates for background spectra and degradation of component performance over time. IR spectral information and chemical analysis of the samples is determined by using one or more IR sources, sampling accessories for positioning the samples, optically dispersive elements, a focal plane array (FPA) arranged to detect the dispersed light beams, and a processor and display to control the FPA, and display an IR spectrograph. Fiber-optic coupling can be used to allow remote sensing. Portability, reliability, and ruggedness is enhanced due to the no-moving part construction. Applications include determining time-resolved orientation and characteristics of materials, including polymer monolayers. Orthogonal polarizers may be used to determine certain material characteristics.

  14. Particle beam fusion progress report for 1989

    SciTech Connect (OSTI)

    Sweeney, M.A.

    1994-08-01

    This report summarizes the progress on the pulsed power approach to inertial confinement fusion. In 1989, the authors achieved a proton focal intensity of 5 TW/cm{sup 2} on PBFA-II in a 15-cm-radius applied magnetic-field (applied-B) ion diode. This is an improvement by a factor of 4 compared to previous PBFA-II experiments. They completed development of the three-dimensional (3-D), electromagnetic, particle-in-cell code QUICKSILVER and obtained the first 3-D simulations of an applied-B ion diode. The simulations, together with analytic theory, suggest that control of electromagnetic instabilities could reduce ion divergence. In experiments using a lithium fluoride source, they delivered 26 kJ of lithium energy to the diode axis. Rutherford-scattered ion diagnostics have been developed and tested using a conical foil located inside the diode. They can now obtain energy density profiles by using range filters and recording ion images on nuclear track recording film. Timing uncertainties in power flow experiments on PBFA-II have been reduced by a factor of 5. They are investigating three plasma opening switches that use magnetic fields to control and confine the injected plasma. These new switches provide better power flow than the standard plasma erosion switch. Advanced pulsed-power fusion drivers will require extraction-geometry applied-B ion diodes. During this reporting period, progress was made in evaluating the generation, transport, and focus of multiple ion beams in an extraction geometry and in assessing the probable damage to a target chamber first wall.

  15. Mass spectrometer and methods of increasing dispersion between ion beams

    DOE Patents [OSTI]

    Appelhans, Anthony D.; Olson, John E.; Delmore, James E.

    2006-01-10

    A mass spectrometer includes a magnetic sector configured to separate a plurality of ion beams, and an electrostatic sector configured to receive the plurality of ion beams from the magnetic sector and increase separation between the ion beams, the electrostatic sector being used as a dispersive element following magnetic separation of the plurality of ion beams. Other apparatus and methods are provided.

  16. Electrtostatic Beam-Plasma Thruster | Princeton Plasma Physics Lab

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

    Electrtostatic Beam-Plasma Thruster Electrostatic beam-plasma thruster utilizes beam of energetic electrons to generate the plasma from which ions are extracted and accelerated to generate the thrust. The accelerated ions are neutralized by the electrons from the beam. No.: M-894 Inventor(s): Yevgeny Raitses

  17. Reliability of Beam Loss Monitor Systems for the Large Hadron Collider

    SciTech Connect (OSTI)

    Guaglio, G.; Dehning, B.; Santoni, C.

    2005-06-08

    The increase of beam energy and beam intensity, together with the use of super conducting magnets, opens new failure scenarios and brings new criticalities for the whole accelerator protection system. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system, and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses at 7 TeV and assisted by the Fast Beam Current Decay Monitors at 450 GeV. At medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standard databases. All the data has been processed by reliability software (Isograph). The analysis spaces from the components data to the system configuration.

  18. World record neutron beam at Los Alamos National Laboratory

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

    World record neutron beam at LANL World record neutron beam at Los Alamos National Laboratory Scientists have created the largest neutron beam ever made by a short-pulse laser, breaking a world record. July 10, 2012 Tom Hurry of Plasma Physics adjusts the target positioner and particle beam diagnostics prior to an experiment at Trident. Tom Hurry of Plasma Physics adjusts the target positioner and particle beam diagnostics prior to an experiment at Trident. Contact Kevin Roark Communications

  19. Polarization of fast particle beams by collisional pumping

    DOE Patents [OSTI]

    Stearns, J.W.; Kaplan, S.N.; Pyle, R.V.; Anderson, L.W.; Schlachter, A.S.; Ruby, L.

    1984-10-19

    The invention relates to method and apparatus for polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and generating a thick electron-spin-polarized medium positioned as a target for said beam, said medium being sufficiently thick to allow said beam to interact with said medium to produce collisional pumping whereby said particle beam becomes highly polarized.

  20. Inhomogeneity smoothing using density valley formed by ion beam deposition

    Office of Scientific and Technical Information (OSTI)

    in ICF fuel pellet (Journal Article) | SciTech Connect Inhomogeneity smoothing using density valley formed by ion beam deposition in ICF fuel pellet Citation Details In-Document Search Title: Inhomogeneity smoothing using density valley formed by ion beam deposition in ICF fuel pellet We study the beam non-uniformity smoothing effect of the radiation transport in the density valley formed by an ion-beam deposition in an ion-beam inertial confinement fusion pellets by numerical simulation.

  1. Noninterceptive method to measure longitudinal Twiss parameters of a beam

    Office of Scientific and Technical Information (OSTI)

    in a hadron linear accelerator using beam position monitors (Journal Article) | DOE PAGES Published Article: Noninterceptive method to measure longitudinal Twiss parameters of a beam in a hadron linear accelerator using beam position monitors Title: Noninterceptive method to measure longitudinal Twiss parameters of a beam in a hadron linear accelerator using beam position monitors Authors: Shishlo, A. ; Aleksandrov, A. Publication Date: 2013-06-11 OSTI Identifier: 1102839 Type: Published

  2. Noninterceptive method to measure longitudinal Twiss parameters of a beam

    Office of Scientific and Technical Information (OSTI)

    in a hadron linear accelerator using beam position monitors (Journal Article) | SciTech Connect Noninterceptive method to measure longitudinal Twiss parameters of a beam in a hadron linear accelerator using beam position monitors Citation Details In-Document Search Title: Noninterceptive method to measure longitudinal Twiss parameters of a beam in a hadron linear accelerator using beam position monitors Authors: Shishlo, A. ; Aleksandrov, A. Publication Date: 2013-06-11 OSTI Identifier:

  3. H{sup -} beam transport experiments in a solenoid low energy beam transport

    SciTech Connect (OSTI)

    Gabor, C.; Back, J. J.; Faircloth, D. C.; Lawrie, S. R.; Letchford, A. P.; Izaola, Z.

    2012-02-15

    The Front End Test Stand (FETS) is located at Rutherford Appleton Laboratory and aims for a high current, fast chopped 3 MeV H{sup -} ion beam suitable for future high power proton accelerators like ISIS upgrade. The main components of the front end are the Penning ion source, a low energy beam transport line, an radio-frequency quadrupole (RFQ) and a medium energy beam transport (MEBT) providing also a chopper section and rebuncher. FETS is in the stage of commissioning its low energy beam transport (LEBT) line consisting of three solenoids. The LEBT has to transport an H{sup -} high current beam (up to 60 mA) at 65 keV. This is the injection energy of the beam into the RFQ. The main diagnostics are slit-slit emittance scanners for each transversal plane. For optimizing the matching to the RFQ, experiments have been performed with a variety of solenoid settings to better understand the actual beam transport. Occasionally, source parameters such as extractor slit width and beam energy were varied as well. The paper also discusses simulations based on these measurements.

  4. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

    Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

    1995-08-08

    A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

  5. Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude

    DOE Patents [OSTI]

    Bogaty, John M. (Lombard, IL); Clifft, Benny E. (Park Forest, IL); Bollinger, Lowell M. (Downers Grove, IL)

    1995-01-01

    A beam current limiter for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity.

  6. LHC RF System Time-Domain Simulation

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.

    2010-09-14

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  7. High power linear pulsed beam annealer

    DOE Patents [OSTI]

    Strathman, Michael D. (Concord, CA); Sadana, Devendra K. (Berkeley, CA); True, Richard B. (Sunnyvale, CA)

    1983-01-01

    A high power pulsed electron beam is produced in a system comprised of an electron gun having a heated cathode, control grid, focus ring, and a curved drift tube. The drift tube is maintained at a high positive voltage with respect to the cathode to accelerate electrons passing through the focus ring and to thereby eliminate space charge. A coil surrounding the curved drift tube provides a magnetic field which maintains the electron beam focused about the axis of the tube and imparts motion on electrons in a spiral path for shallow penetration of the electrons into a target. The curvature of the tube is selected so there is no line of sight between the cathode and a target holder positioned within a second drift tube spaced coaxially from the curved tube. The second tube and the target holder are maintained at a reference voltage that decelerates the electrons. A second coil surrounding the second drift tube maintains the electron beam focused about the axis of the second drift tube and compresses the electron beam to the area of the target. The target holder can be adjusted to position the target where the cross section of the beam matches the area of the target.

  8. Optical parametric osicllators with improved beam quality

    DOE Patents [OSTI]

    Smith, Arlee V.; Alford, William J.

    2003-11-11

    An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

  9. Method for measuring and controlling beam current in ion beam processing

    DOE Patents [OSTI]

    Kearney, Patrick A. (Livermore, CA); Burkhart, Scott C. (Livermore, CA)

    2003-04-29

    A method for producing film thickness control of ion beam sputter deposition films. Great improvements in film thickness control is accomplished by keeping the total current supplied to both the beam and suppressor grids of a radio frequency (RF) in beam source constant, rather than just the current supplied to the beam grid. By controlling both currents, using this method, deposition rates are more stable, and this allows the deposition of layers with extremely well controlled thicknesses to about 0.1%. The method is carried out by calculating deposition rates based on the total of the suppressor and beam currents and maintaining the total current constant by adjusting RF power which gives more consistent values.

  10. Simulation Studies of Beam-Beam Effects of a Ring-Ring Electron-Ion Collider Based on CEBAF

    SciTech Connect (OSTI)

    Yuhong Zhang,Ji Qiang

    2009-05-01

    The collective beam-beam effect can potentially cause a rapid growth of beam sizes and reduce the luminosity of a collider to an unacceptably low level. The ELIC, a proposed ultra high luminosity electron-ion collider based on CEBAF, employs high repetition rate crab crossing colliding beams with very small bunch transverse sizes and very short bunch lengths, and collides them at up to 4 interaction points with strong final focusing. All of these features can make the beam-beam effect challenging. In this paper, we present simulation studies of the beam-beam effect in ELIC using a self-consistent strong-strong beam-beam simulation code developed at Lawrence Berkeley National Laboratory. This simulation study is used for validating the ELIC design and for searching for an optimal parameter set.

  11. On timing properties of LYSO-based calorimeters

    SciTech Connect (OSTI)

    Anderson, D.; Apresyan, A.; Bornheim, A.; Duarte, J.; Pena, C.; Ronzhin, A.; Spiropulu, M.; Trevor, J.; Xie, S.

    2015-04-23

    We present test beam studies and results on the timing performance and characterization of the time resolution of Lutetium–Yttrium Orthosilicate (LYSO)-based calorimeters. We also demonstrate that a time resolution of 30 ps is achievable for a particular design. Additionally, we discuss precision timing calorimetry as a tool for the mitigation of physics object performance degradation effects due to the large number of simultaneous interactions in the high luminosity environment foreseen at the Large Hadron Collider.

  12. The CNAO dose delivery system for modulated scanning ion beam radiotherapy

    SciTech Connect (OSTI)

    Giordanengo, S.; Marchetto, F.; Garella, M. A.; Donetti, M.; Bourhaleb, F.; Monaco, V.; Hosseini, M. A.; Peroni, C.; Sacchi, R.; Cirio, R.; Ciocca, M.; Mirandola, A.

    2015-01-15

    Purpose: This paper describes the system for the dose delivery currently used at the Centro Nazionale di Adroterapia Oncologica (CNAO) for ion beam modulated scanning radiotherapy. Methods: CNAO Foundation, Istituto Nazionale di Fisica Nucleare and University of Torino have designed, built, and commissioned a dose delivery system (DDS) to monitor and guide ion beams accelerated by a dedicated synchrotron and to distribute the dose with a full 3D scanning technique. Protons and carbon ions are provided for a wide range of energies in order to cover a sizable span of treatment depths. The target volume, segmented in several layers orthogonally to the beam direction, is irradiated by thousands of pencil beams which must be steered and held to the prescribed positions until the prescribed number of particles has been delivered. For the CNAO beam lines, these operations are performed by the DDS. The main components of this system are two independent beam monitoring detectors, called BOX1 and BOX2, interfaced with two control systems performing the tasks of real-time fast and slow control, and connected to the scanning magnets and the beam chopper. As a reaction to any condition leading to a potential hazard, a DDS interlock signal is sent to the patient interlock system which immediately stops the irradiation. The essential tasks and operations performed by the DDS are described following the data flow from the treatment planning system through the end of the treatment delivery. Results: The ability of the DDS to guarantee a safe and accurate treatment was validated during the commissioning phase by means of checks of the charge collection efficiency, gain uniformity of the chambers, and 2D dose distribution homogeneity and stability. A high level of reliability and robustness has been proven by three years of system activity needing rarely more than regular maintenance and working with 100% uptime. Four identical and independent DDS devices have been tested showing comparable performances and are presently in use on the CNAO beam lines for clinical activity. Conclusions: The dose delivery system described in this paper is one among the few worldwide existing systems to operate ion beam for modulated scanning radiotherapy. At the time of writing, it has been used to treat more than 350 patients and it has proven to guide and control the therapeutic pencil beams reaching performances well above clinical requirements. In particular, in terms of dose accuracy and stability, daily quality assurance measurements have shown dose deviations always lower than the acceptance threshold of 5% and 2.5%, respectively.

  13. Variation of Langmuir wave polarization with electron beam speed in type III radio bursts

    SciTech Connect (OSTI)

    Malaspina, David M.; Cairns, Iver H.; Ergun, Robert E.

    2013-06-13

    Observations by the twin STEREO spacecraft of in-situ electric field waveforms and radio signatures associated with type III radio bursts have demonstrated that the polarization of electron beam-driven waves near the local plasma frequency depends strongly on the speed of the driving electron beam. We expand upon a previous study by including all radio bursts with in-situ waveforms observed by STEREO in 2011. The expanded data set contains five times more radio bursts (35 up from 7) and three times as many Langmuir waves (663 up from 168). While this expanded study supports the results of the original study, that faster (slower) beam electrons drive waves with strong (weak) electric fields perpendicular to the local magnetic field, the larger data set emphasizes that the observation of strong perpendicular electric fields at high electron beam speeds is probabilistic rather than definite. This property supports the interpretation of wave polarization dependence on beam speed as Langmuir/z-mode waves shifted to small wave number through interaction with turbulent solar wind density fluctuations.

  14. Diamond detector for high rate monitors of fast neutrons beams

    SciTech Connect (OSTI)

    Giacomelli, L.; Rebai, M.; Cippo, E. Perelli; Tardocchi, M.; Fazzi, A.; Andreani, C.; Pietropaolo, A.; Frost, C. D.; Rhodes, N.; Schooneveld, E.; Gorini, G.

    2012-06-19

    A fast neutron detection system suitable for high rate measurements is presented. The detector is based on a commercial high purity single crystal diamond (SDD) coupled to a fast digital data acquisition system. The detector was tested at the ISIS pulsed spallation neutron source. The SDD event signal was digitized at 1 GHz to reconstruct the deposited energy (pulse amplitude) and neutron arrival time; the event time of flight (ToF) was obtained relative to the recorded proton beam signal t{sub 0}. Fast acquisition is needed since the peak count rate is very high ({approx}800 kHz) due to the pulsed structure of the neutron beam. Measurements at ISIS indicate that three characteristics regions exist in the biparametric spectrum: i) background gamma events of low pulse amplitudes; ii) low pulse amplitude neutron events in the energy range E{sub dep}= 1.5-7 MeV ascribed to neutron elastic scattering on {sup 12}C; iii) large pulse amplitude neutron events with E{sub n} < 7 MeV ascribed to {sup 12}C(n,{alpha}){sup 9}Be and 12C(n,n')3{alpha}.

  15. Performance of the upgraded NSLS beam position monitors

    SciTech Connect (OSTI)

    Nawrocky, R.J.; Keane, J.

    1997-07-01

    The design and initial performance of the original NSLS beam position monitor were described by J. Bittner and R. Biscardi in 1989. The receiver, which processes signals from four button type pick-up electrodes by time-division multiplexing, operates at the third harmonic of the ring rf frequency (158.66 MHz). It has an output bandwidth of about 2 kHz and a dynamic signal range of approximately 36 dB. A total of 92 receivers have been installed in the NSLS X-ray and VUV storage rings for orbit monitoring and for real time feedback. As part of a continuous effort to improve the NSLS storage ring performance, the BPMs as well as other instrumentation systems have also been undergoing upgrades over the past two years to improve their performance. In the BPM, the front end has been modified to prevent saturation of the rf multiplexing switch, the detector operating point was changed to improve output signal linearity, the dynamic range was increased to over 60 dB, and the gain calibration was standardized to 0.5 volts/mm (i.e. 2 {micro}m/mV). This paper describes the BPM modifications and presents some performance data and measurements on stored beam.

  16. APS User Information | Advanced Photon Source

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

    to APS, site access permission, user agreement, training, contactbio information your research: proposals, ESAFs, EEFs action items: things that need to be addressed before you...

  17. Beamline 4-ID-D | Advanced Photon Source

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

    Publications XSD-MM Home MM Advisory Committees FAQs Beamline Info Instrumentation Optics Software Magnet Materials Internal Useful Links Current APS status ESAF System GUP...

  18. Frontiers of particle beam physics

    SciTech Connect (OSTI)

    Sessler, A.M.

    1989-11-01

    First, a review is given of various highly-developed techniques for particle handling which are, nevertheless, being vigorously advanced at the present time. These include soft superconductor radio frequency cavities, hard superconductor magnets, cooling rings for ions and anti-protons, and damping rings for electrons. Second, attention is focused upon novel devices for particle generation, acceleration, and focusing. These include relativistic klystrons and free electron laser power sources, binary power multipliers, photocathodes, switched-power linacs, plasma beat-wave accelerators, plasma wake-field accelerators, plasma lenses, plasma adiabatic focusers and plasma compensators. 12 refs.

  19. Confined ion beam sputtering device and method

    DOE Patents [OSTI]

    Sharp, Donald J. (Albuquerque, NM)

    1988-01-01

    A hollow cylindrical target, lined internally with a sputter deposit material and open at both ends, surrounds a substrate on which sputtered deposition is to be obtained. An ion beam received through either one or both ends of the open cylindrical target is forced by a negative bias applied to the target to diverge so that ions impinge at acute angles at different points of the cylindrical target surface. The ion impingement results in a radially inward and downstream directed flux of sputter deposit particles that are received by the substrate. A positive bias applied to the substrate enhances divergence of the approaching ion beams to generate a higher sputtered deposition flux rate. Alternatively, a negative bias applied to the substrate induces the core portion of the ion beams to reach the substrate and provide ion polishing of the sputtered deposit thereon.

  20. Confined ion beam sputtering device and method

    DOE Patents [OSTI]

    Sharp, D.J.

    1986-03-25

    A hollow cylindrical target, lined internally with a sputter deposit material and open at both ends, surrounds a substrate on which sputtered deposition is to be obtained. An ion beam received through either one or both ends of the open cylindrical target is forced by a negative bias applied to the target to diverge so that ions impinge at acute angles at different points of the cylindrical target surface. The ion impingement results in a radially inward and downstream directed flux of sputter deposit particles that are received by the substrate. A positive bias applied to the substrate enhances divergence of the approaching ion beams to generate a higher sputtered deposition flux rate. Alternatively, a negative bias applied to the substrate induces the core portion of the ion beams to reach the substrate and provide ion polishing of the sputtered deposit thereon.

  1. BeamDyn: A High-Fidelity Wind Turbine Blade Solver in the FAST Modular Framework: Preprint

    SciTech Connect (OSTI)

    Wang, Q.; Sprague, M.; Jonkman, J.; Johnson, N.

    2015-01-01

    BeamDyn, a Legendre-spectral-finite-element implementation of geometrically exact beam theory (GEBT), was developed to meet the design challenges associated with highly flexible composite wind turbine blades. In this paper, the governing equations of GEBT are reformulated into a nonlinear state-space form to support its coupling within the modular framework of the FAST wind turbine computer-aided engineering (CAE) tool. Different time integration schemes (implicit and explicit) were implemented and examined for wind turbine analysis. Numerical examples are presented to demonstrate the capability of this new beam solver. An example analysis of a realistic wind turbine blade, the CX-100, is also presented as validation.

  2. From super beams to neutrino factories

    SciTech Connect (OSTI)

    Bross, Alan; /Fermilab

    2009-11-01

    The Neutrino Factory, which produces an extremely intense source of flavor-tagged neutrinos from muon decays in a storage ring, arguably gives the best physics reach for CP violation, as well as virtually all parameters in the neutrino oscillation parameter space. I will briefly describe the physics capabilities of the baseline Neutrino Factory as compared to other possible future facilities ({beta}-beam and super-beam facilities), give an overview of the accelerator complex and describe in detail the current international R&D program.

  3. The New Uppsala Neutron Beam Facility

    SciTech Connect (OSTI)

    Pomp, S.; Blomgren, J.; Hildebrand, A.; Johansson, C.; Mermod, P.; Oesterlund, M.; Prokofiev, A.V.; Bystroem, O.; Ekstroem, C.; Haag, N.; Jonsson, O.; Reistad, D.; Renberg, P.-U.; Wessman, D.; Ziemann, V.; Nilsson, L.; Olsson, N.; Tippawan, U.

    2005-05-24

    A new quasi-monoenergetic neutron beam facility has been constructed at the The Svedberg Laboratory (TSL) in Uppsala, Sweden. Key features include an energy range of 20 to 175 MeV, high fluxes, and the possibility of large-area fields. Besides cross-section measurements, the new facility has been designed specifically to provide optimal conditions for testing of single-event effects in electronics and for dosimetry development. First results of the beam characterization measurements performed in early 2004 are reported.

  4. Polarized electron beams at milliampere average current

    SciTech Connect (OSTI)

    Poelker, Matthew

    2013-11-01

    This contribution describes some of the challenges associated with developing a polarized electron source capable of uninterrupted days-long operation at milliAmpere average beam current with polarization greater than 80%. Challenges will be presented in the context of assessing the required level of extrapolation beyond the performance of today's CEBAF polarized source operating at ~ 200 uA average current. Estimates of performance at higher current will be based on hours-long demonstrations at 1 and 4 mA. Particular attention will be paid to beam-related lifetime-limiting mechanisms, and strategies to construct a photogun that operate reliably at bias voltage > 350kV.

  5. Moving receive beam method and apparatus for synthetic aperture radar

    DOE Patents [OSTI]

    Kare, Jordin T. (San Ramon, CA)

    2001-01-01

    A method and apparatus for improving the performance of Synthetic Aperture Radar (SAR) systems by reducing the effect of "edge losses" associated with nonuniform receiver antenna gain. By moving the receiver antenna pattern in synchrony with the apparent motion of the transmitted pulse along the ground, the maximum available receiver antenna gain can be used at all times. Also, the receiver antenna gain for range-ambiguous return signals may be reduced, in some cases, by a large factor. The beam motion can be implemented by real-time adjustment of phase shifters in an electronically-steered phased-array antenna or by electronic switching of feed horns in a reflector antenna system.

  6. RHIC electron lens beam transport system design considerations

    SciTech Connect (OSTI)

    Gu, X.; Pikin, A.; Okamura, M.; Fischer, W.; Luo, Y.; Gupta, R.; Hock, J.; Jain, A.; Raparia, D.

    2010-10-01

    To apply head-on beam-beam compensation for RHIC, two electron lenses are designed and will be installed at IP10. Electron beam transport system is one of important subsystem, which is used to transport electron beam from electron gun side to collector side. This system should be able to change beam size inside superconducting magnet and control beam position with 5 mm in horizontal and vertical plane. Some other design considerations for this beam transport system are also reported in this paper. The head-on beam-beam effect is one of important nonlinear source in storage ring and linear colliders, which have limited the luminosity improvement of many colliders, such as SppS, Tevatron and RHIC. In order to enhance the performance of colliders, beam-beam effects can be compensated with direct space charge compensation, indirect space charge compensation or betatron phase cancellation scheme. Like other colliders, indirect space charge compensation scheme (Electron Lens) was also proposed for Relativistic Heavy Ion Collider (RHIC) beam-beam compensation at Brookhaven National Laboratory. The two similar electron lenses are located in IR10 between the DX magnets. One RHIC electron lens consists of one DC electron gun, one superconducting magnet, one electron collector and beam transport system.

  7. Compact and high-particle-flux thermal-lithium-beam probe system for measurement of two-dimensional electron density profile

    SciTech Connect (OSTI)

    Shibata, Y. Manabe, T.; Ohno, N.; Takagi, M.; Kajita, S.; Tsuchiya, H.; Morisaki, T.

    2014-09-15

    A compact and high-particle-flux thermal-lithium-beam source for two-dimensional measurement of electron density profiles has been developed. The thermal-lithium-beam oven is heated by a carbon heater. In this system, the maximum particle flux of the thermal lithium beam was ?4 10{sup 19} m{sup ?2} s{sup ?1} when the temperature of the thermal-lithium-beam oven was 900 K. The electron density profile was evaluated in the small tokamak device HYBTOK-II. The electron density profile was reconstructed using the thermal-lithium-beam probe data and this profile was consistent with the electron density profile measured with a Langmuir electrostatic probe. We confirm that the developed thermal-lithium-beam probe can be used to measure the two-dimensional electron density profile with high time and spatial resolutions.

  8. Development of a He{sup -} and He{sup 0} beam source for alpha particle measurement in a burning plasma

    SciTech Connect (OSTI)

    Tanaka, N.; Sasao, M.; Terai, K.; Okamoto, A.; Kitajima, S.; Yamaoka, H.; Wada, M.

    2012-02-15

    Proof of principle experiments of neutral helium beam production for alpha particle diagnostics was carried out on a test stand. Negative helium ions were produced in the Li charge exchange cell, in which stable and long time operation was possible. He{sup -} beam was accelerated to 157 keV. Finally, He{sup 0} beam was successfully produced after the flight in the drift-tube through the auto-electron-detachment process from He{sup -} to He{sup 0}. A neutral beam detector using a pyroelectric device was also developed to measure He{sup 0} beam intensity. The metastable component in the neutral helium beam was found to be less than 2%.

  9. Characterizing and Controlling Beam Losses at the LANSCE Facility

    SciTech Connect (OSTI)

    Rybarcyk, Lawrence J.

    2012-09-12

    The Los Alamos Neutron Science Center (LANSCE) currently provides 100-MeV H{sup +} and 800-MeV H{sup -} beams to several user facilities that have distinct beam requirements, e.g. intensity, micropulse pattern, duty factor, etc. Minimizing beam loss is critical to achieving good performance and reliable operation, but can be challenging in the context of simultaneous multi-beam delivery. This presentation will discuss various aspects related to the observation, characterization and minimization of beam loss associated with normal production beam operations in the linac.

  10. Analysis of beam loss induced abort kicker instability

    SciTech Connect (OSTI)

    Zhang W.; Sandberg, J.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Pai, C.; Tan, Y.

    2012-05-20

    Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems and improved stability of the RHIC operation.

  11. Compact two-beam push-pull free electron laser

    DOE Patents [OSTI]

    Hutton, Andrew (Yorktown, VA)

    2009-03-03

    An ultra-compact free electron laser comprising a pair of opposed superconducting cavities that produce identical electron beams moving in opposite directions such that each set of superconducting cavities accelerates one electron beam and decelerates the other electron beam. Such an arrangement, allows the energy used to accelerate one beam to be recovered and used again to accelerate the second beam, thus, each electron beam is decelerated by a different structure than that which accelerated it so that energy exchange rather than recovery is achieved resulting in a more compact and highly efficient apparatus.

  12. Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.-P.; Sterbini, G.; Zimmermann, F.; Kim, H.-J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.

    2009-01-12

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  13. Long-range and head-on beam-beam compensation studies in RHIC with lessons for the LHC

    SciTech Connect (OSTI)

    Fischer,W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J. -P.; Sterbini, G.; Zimmermann, F.; Kim, H. -J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.

    2008-11-24

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are also important consideration for the LHC upgrades. To mitigate long-range effects current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. To reduce the head-on beam-beam effect electron lenses were proposed for both RIDC and the LHC. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  14. Long-Range And Head-On Beam-Beam Compensation Studies in RHIC With Lessons for the LHC

    SciTech Connect (OSTI)

    Fischer, W.; Luo, Y.; Abreu, N.; Calaga, R.; Montag, C.; Robert-Demolaize, G.; Dorda, U.; Koutchouk, J.P.; Sterbini, G.; Zimmermann, F.; Kim, H.J.; Sen, T.; Shiltsev, V.; Valishev, A.; Qiang, J.; Kabel, A.; /SLAC

    2011-11-28

    Long-range as well as head-on beam-beam effects are expected to limit the LHC performance with design parameters. They are are also important consideration for the LHC upgrades. To mitigate long-range effects, current carrying wires parallel to the beam were proposed. Two such wires are installed in RHIC where they allow studying the effect of strong long-range beam-beam effects, as well as the compensation of a single long-range interaction. The tests provide benchmark data for simulations and analytical treatments. Electron lenses were proposed for both RHIC and the LHC to reduce the head-on beam-beam effect. We present the experimental long-range beam-beam program at RHIC and report on head-on compensations studies based on simulations.

  15. Ultrafast spectroscopy of super high frequency mechanical modes of doubly clamped beams

    SciTech Connect (OSTI)

    Ristow, Oliver; Merklein, Moritz; Grossmann, Martin; Hettich, Mike; Schubert, Martin; Bruchhausen, Axel; Scheer, Elke; Dekorsy, Thomas; Barretto, Elaine C. S.; Grebing, Jochen; Erbe, Artur; Mounier, Denis; Gusev, Vitalyi

    2013-12-02

    We use ultrafast pump-probe spectroscopy to study the mechanical vibrations in the time domain of doubly clamped silicon nitride beams. Beams with two different clamping conditions are investigated. Finite element method calculations are performed to analyse the mode spectra of both structures. By calculating the strain integral on the surface of the resonators, we are able to reproduce the effect of the detection mechanism and identify all the measured modes. We show that our spectroscopy technique combined with our modelling tools allow the investigation of several different modes in the super high frequency range (3-30?GHz) and above, bringing more information about the vibration modes of nanomechanical resonators.

  16. UGE Scheduler Cycle Time

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

    UGE Scheduler Cycle Time UGE Scheduler Cycle Time Genepool Cycle Time Genepool Daily Genepool Weekly Phoebe Cycle Time Phoebe Daily Phoebe Weekly What is the Scheduler Cycle? The...

  17. Focused ion beam micromilling and articles therefrom

    DOE Patents [OSTI]

    Lamartine, Bruce C. (Los Alamos, NM); Stutz, Roger A. (Los Alamos, NM)

    1998-01-01

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are isclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters.

  18. Beam current controller for laser ion source

    DOE Patents [OSTI]

    Okamura, Masahiro

    2014-10-28

    The present invention relates to the design and use of an ion source with a rapid beam current controller for experimental and medicinal purposes. More particularly, the present invention relates to the design and use of a laser ion source with a magnetic field applied to confine a plasma flux caused by laser ablation.

  19. Ion beam analysis techniques in interdisciplinary applications

    SciTech Connect (OSTI)

    Respaldiza, Miguel A.; Ager, Francisco J.

    1999-11-16

    The ion beam analysis techniques emerge in the last years as one of the main applications of electrostatic accelerators. A short summary of the most used IBA techniques will be given as well as some examples of applications in interdisciplinary sciences.

  20. Focused ion beam micromilling and articles therefrom

    DOE Patents [OSTI]

    Lamartine, B.C.; Stutz, R.A.

    1998-06-30

    An ultrahigh vacuum focused ion beam micromilling apparatus and process are disclosed. Additionally, a durable data storage medium using the micromilling process is disclosed, the durable data storage medium capable of storing, e.g., digital or alphanumeric characters as well as graphical shapes or characters. 6 figs.

  1. Notes on beam dynamics in linear accelerators

    SciTech Connect (OSTI)

    Gluckstern, R.L.

    1980-09-01

    A collection of notes, on various aspects of beam dynamics in linear accelerators, which were produced by the author during five years (1975 to 1980) of consultation for the LASL Accelerator Technology (AT) Division and Medium-Energy Physics (MP) Division is presented.

  2. Moving core beam energy absorber and converter

    DOE Patents [OSTI]

    Degtiarenko, Pavel V.

    2012-12-18

    A method and apparatus for the prevention of overheating of laser or particle beam impact zones through the use of a moving-in-the-coolant-flow arrangement for the energy absorbing core of the device. Moving of the core spreads the energy deposition in it in 1, 2, or 3 dimensions, thus increasing the effective cooling area of the device.

  3. SSRL BEAM PORT SCHEDULE FY2012

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

    BEAM LINE 7-1 Nov. 05, 2012 Nov. 06, 2012 Nov. 07, 2012 Nov. 08, 2012 Nov. 09, 2012 Nov. 10, 2012 Nov. 11, 2012 DOWN DOWN DOWN 8803 C.SMITH 8803 C.SMITH 8803 C.SMITH 8803 C.SMITH ...

  4. Trirotron: triode rotating beam radio frequency amplifier

    DOE Patents [OSTI]

    Lebacqz, Jean V. (Stanford, CA)

    1980-01-01

    High efficiency amplification of radio frequencies to very high power levels including: establishing a cylindrical cloud of electrons; establishing an electrical field surrounding and coaxial with the electron cloud to bias the electrons to remain in the cloud; establishing a rotating electrical field that surrounds and is coaxial with the steady field, the circular path of the rotating field being one wavelength long, whereby the peak of one phase of the rotating field is used to accelerate electrons in a beam through the bias field in synchronism with the peak of the rotating field so that there is a beam of electrons continuously extracted from the cloud and rotating with the peak; establishing a steady electrical field that surrounds and is coaxial with the rotating field for high-energy radial acceleration of the rotating beam of electrons; and resonating the rotating beam of electrons within a space surrounding the second field, the space being selected to have a phase velocity equal to that of the rotating field to thereby produce a high-power output at the frequency of the rotating field.

  5. 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 convolution algorithms failed to accurately calculate couch attenuation. The collapsed cone and superposition algorithms calculated attenuation within an absolute error of {+-}1.2% for 6 MV and {+-}0.8% for 10 MV for gantry angles from 0 deg. to 40 deg. Some differences in attenuation were observed dependent on how the couch was contoured. Conclusions: These results demonstrate that the presence of the iBEAM evo carbon fiber couch increases the surface dose and dose in the build up region. The inclusion of the couch in the planning scan is limited by the field of view employed and the couch height at the time of CT scanning.

  6. Instrumentation and Beam Dynamics Study of Advanced Electron-Photon Facility in Indiana University

    SciTech Connect (OSTI)

    Luo, Tianhuan; /Indiana U.

    2011-08-01

    The Advanced eLectron-PHoton fAcility (ALPHA) is a compact electron accelerator under construction and being commissioned at the Indiana University Center for Exploration of Energy and Matter (CEEM). In this thesis, we have studied the refurbished Cooler Injector Synchrotron (CIS) RF cavity using both the transmission line model and SUPERFISH simulation. Both low power and high power RF measurements have been carried out to characterize the cavity. Considering the performance limit of ferrite, we have designed a new ferrite loaded, co-axial quarter wave like cavity with similar structure but a more suitable ferrite material. We have also designed a traveling wave stripline kicker for fast extraction by POISSON and Microwave Studio. The strips geometry is trimmed to maximize the uniformity of the kicking field and match the impedance of the power cables. The time response simulation shows the kicker is fast enough for machine operation. The pulsed power supply requirement has also been specified. For the beam diagnosis in the longitudinal direction, we use a wideband Wall Gap Monitor (WGM) served in CIS. With proper shielding and amplification to get good WGM signal, we have characterized the injected and extracted beam signal in single pass commissioning, and also verified the debunching effect of the ALPHA storage ring. A modulation-demodulation signal processing method is developed to measure the current and longitudinal profile of injected beam. By scanning the dipole strength in the injection line, we have reconstructed the tomography of the longitudinal phase space of the LINAC beam. In the accumulation mode, ALPHA will be operated under a low energy and high current condition, where intra beam scattering (IBS) becomes a dominant effect on the beam emittance. A self consistent simulation, including IBS effect, gas scattering and linear coupling, has been carried out to calculate the emittance of the stored beam.

  7. SU-E-J-72: Geant4 Simulations of Spot-Scanned Proton Beam Treatment Plans

    SciTech Connect (OSTI)

    Kanehira, T; Sutherland, K; Matsuura, T; Umegaki, K; Shirato, H [Hokkaido University, Sapporo, Hokkaido (Japan)

    2014-06-01

    Purpose: To evaluate density inhomogeneities which can effect dose distributions for real-time image gated spot-scanning proton therapy (RGPT), a dose calculation system, using treatment planning system VQA (Hitachi Ltd., Tokyo) spot position data, was developed based on Geant4. Methods: A Geant4 application was developed to simulate spot-scanned proton beams at Hokkaido University Hospital. A CT scan (0.98 0.98 1.25 mm) was performed for prostate cancer treatment with three or four inserted gold markers (diameter 1.5 mm, volume 1.77 mm3) in or near the target tumor. The CT data was read into VQA. A spot scanning plan was generated and exported to text files, specifying the beam energy and position of each spot. The text files were converted and read into our Geant4-based software. The spot position was converted into steering magnet field strength (in Tesla) for our beam nozzle. Individual protons were tracked from the vacuum chamber, through the helium chamber, steering magnets, dose monitors, etc., in a straight, horizontal line. The patient CT data was converted into materials with variable density and placed in a parametrized volume at the isocenter. Gold fiducial markers were represented in the CT data by two adjacent voxels (volume 2.38 mm3). 600,000 proton histories were tracked for each target spot. As one beam contained about 1,000 spots, approximately 600 million histories were recorded for each beam on a blade server. Two plans were considered: two beam horizontal opposed (90 and 270 degree) and three beam (0, 90 and 270 degree). Results: We are able to convert spot scanning plans from VQA and simulate them with our Geant4-based code. Our system can be used to evaluate the effect of dose reduction caused by gold markers used for RGPT. Conclusion: Our Geant4 application is able to calculate dose distributions for spot scanned proton therapy.

  8. rf beam-current, -phase, and -position monitors

    SciTech Connect (OSTI)

    Young, L.

    1984-12-12

    A prototype rf beam monitor has been tested on the Racetrack Microtron's (RTM) 100 kV injector beam line at the National Bureau of Standards (NBS). This beam monitor is capable of measuring the current, the relative phase, and the position of the beam. The beam is bunched at 2380 MHz for acceleration by the linac in the injector beam line. This train of beam bunches passing through the beam monitor cavities excites the cavities at this resonance frequency of 2380 MHz. Probes in the cavities couple some of the beam-excited rf power out of the cavities. This rf power can be amplified if necessary and then analyzed by a double balanced mixer (DBM). The DBM can also be used as a phase detector. The effective shunt impedance of the cavities was measured with the CW beam. For the position monitor cavity, the shunt impedance is proportional to the displacement from the axis. The measured response of the prototype rf beam current monitor setup is a linear function of beam current. Response of the rf beam-position monitor is also shown. (LEW)

  9. Beam Dynamics Challenges for the ILC

    SciTech Connect (OSTI)

    Kubo, Kiyoshi; Seryi, Andrei; Walker, Nicholas; Wolski, Andy; /Cockcroft Inst. Accel. Sci. Tech.

    2008-02-13

    The International Linear Collider (ILC) is a proposal for 500 GeV center-of-mass electron-positron collider, with a possible upgrade to {approx}1 TeV center-of-mass. At the heart of the ILC are the two {approx}12 km 1.3 GHz superconducting RF (SCRF) linacs which will accelerate the electron and positron beams to an initial maximum energy of 250 GeV each. The Global Design Effort (GDE)--responsible for the world-wide coordination of this uniquely international project--published the ILC Reference Design Report in August of 2007 [1]. The ILC outlined in the RDR design stands on a legacy of over fifteen-years of R&D. The GDE is currently beginning the next step in this ambitious project, namely an Engineering Design phase, which will culminate with the publication of an Engineering Design Report (EDR) in mid-2010. Throughout the history of linear collider development, beam dynamics has played an essential role. In particular, the need for complex computer simulations to predict the performance of the machine has always been crucial, not least because the parameters of the ILC represent in general a large extrapolation from where current machines operate today; many of the critical beam-dynamics features planned for the ILC can ultimately only be truly tested once the ILC has been constructed. It is for this reason that beam dynamics activities will continue to be crucial during the Engineering Design phase, as the available computer power and software techniques allow ever-more complex and realistic models of the machine to be developed. Complementary to the computer simulation efforts are the need for well-designed experiments at beam-test facilities, which--while not necessarily producing a direct demonstration of the ILC-like parameters for the reasons mentioned above--can provide important input and benchmarking for the computer models.

  10. Positive and negative ion beam merging system for neutral beam production

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Reijonen, Jani

    2005-12-13

    The positive and negative ion beam merging system extracts positive and negative ions of the same species and of the same energy from two separate ion sources. The positive and negative ions from both sources pass through a bending magnetic field region between the pole faces of an electromagnet. Since the positive and negative ions come from mirror image positions on opposite sides of a beam axis, and the positive and negative ions are identical, the trajectories will be symmetrical and the positive and negative ion beams will merge into a single neutral beam as they leave the pole face of the electromagnet. The ion sources are preferably multicusp plasma ion sources. The ion sources may include a multi-aperture extraction system for increasing ion current from the sources.

  11. Beam manipulation techniques, nonlinear beam dynamics, and space charge effect in high energy high power accelerators

    SciTech Connect (OSTI)

    Lee, S. Y.

    2014-04-07

    We had carried out a design of an ultimate storage ring with beam emittance less than 10 picometer for the feasibility of coherent light source at X-ray wavelength. The accelerator has an inherent small dynamic aperture. We study method to improve the dynamic aperture and collective instability for an ultimate storage ring. Beam measurement and accelerator modeling are an integral part of accelerator physics. We develop the independent component analysis (ICA) and the orbit response matrix method for improving accelerator reliability and performance. In collaboration with scientists in National Laboratories, we also carry out experimental and theoretical studies on beam dynamics. Our proposed research topics are relevant to nuclear and particle physics using high brightness particle and photon beams.

  12. Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter

    SciTech Connect (OSTI)

    Chuyu Liu

    2012-12-31

    Beam diagnostics is an essential constituent of any accelerator, so that it is named as "organs of sense" or "eyes of the accelerator." Beam diagnostics is a rich field. A great variety of physical effects or physical principles are made use of in this field. Some devices are based on electro-magnetic influence by moving charges, such as faraday cups, beam transformers, pick-ups; Some are related to Coulomb interaction of charged particles with matter, such as scintillators, viewing screens, ionization chambers; Nuclear or elementary particle physics interactions happen in some other devices, like beam loss monitors, polarimeters, luminosity monitors; Some measure photons emitted by moving charges, such as transition radiation, synchrotron radiation monitors and diffraction radiation-which is the topic of the first part of this thesis; Also, some make use of interaction of particles with photons, such as laser wire and Compton polarimeters-which is the second part of my thesis. Diagnostics let us perceive what properties a beam has and how it behaves in a machine, give us guideline for commissioning, controlling the machine and indispensable parameters vital to physics experiments. In the next two decades, the research highlight will be colliders (TESLA, CLIC, JLC) and fourth-generation light sources (TESLA FEL, LCLS, Spring 8 FEL) based on linear accelerator. These machines require a new generation of accelerator with smaller beam, better stability and greater efficiency. Compared with those existing linear accelerators, the performance of next generation linear accelerator will be doubled in all aspects, such as 10 times smaller horizontal beam size, more than 10 times smaller vertical beam size and a few or more times higher peak power. Furthermore, some special positions in the accelerator have even more stringent requirements, such as the interaction point of colliders and wigglor of free electron lasers. Higher performance of these accelerators increases the difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation.

  13. High Precision Tune and Coupling Feedback and Beam Transfer Function Measurements in RHIC

    SciTech Connect (OSTI)

    Minty, M.; Curcio, A.; Dawson, C.; Degen, C.; Luo, Y.; Marr, G.; Martin, B.; Marusic, A.; Mernick, K.; Oddo, P.; Russo, T.; Schoefer, V.; Schroeder, R.; Schultheiss, C.; Wilinski, M.

    2010-05-23

    Precision measurement and control of the betatron tunes and betatron coupling in the Relativistic Heavy Ion Collider (RHIC) are required for establishing and maintaining both good operating conditions and, particularly during the ramp to high beam energies, high proton beam polarization. While the proof-of-principle for simultaneous tune and coupling feedback was successfully demonstrated earlier, routine application of these systems has only become possible recently. Following numerous modifications for improved measurement resolution and feedback control, the time required to establish full-energy beams with the betatron tunes and coupling regulated by feedback was reduced from several weeks to a few hours. A summary of these improvements, select measurements benefitting from the improved resolution and a review of system performance are the subject of this report.

  14. Fast optimization and dose calculation in scanned ion beam therapy

    SciTech Connect (OSTI)

    Hild, S.; Graeff, C.; Trautmann, J.; Kraemer, M.; Zink, K.; Durante, M.; Bert, C.

    2014-07-15

    Purpose: Particle therapy (PT) has advantages over photon irradiation on static tumors. An increased biological effectiveness and active target conformal dose shaping are strong arguments for PT. However, the sensitivity to changes of internal geometry complicates the use of PT for moving organs. In case of interfractionally moving objects adaptive radiotherapy (ART) concepts known from intensity modulated radiotherapy (IMRT) can be adopted for PT treatments. One ART strategy is to optimize a new treatment plan based on daily image data directly before a radiation fraction is delivered [treatment replanning (TRP)]. Optimizing treatment plans for PT using a scanned beam is a time consuming problem especially for particles other than protons where the biological effective dose has to be calculated. For the purpose of TRP, fast optimization and fast dose calculation have been implemented into the GSI in-house treatment planning system (TPS) TRiP98. Methods: This work reports about the outcome of a code analysis that resulted in optimization of the calculation processes as well as implementation of routines supporting parallel execution of the code. To benchmark the new features, the calculation time for therapy treatment planning has been studied. Results: Compared to the original version of the TPS, calculation times for treatment planning (optimization and dose calculation) have been improved by a factor of 10 with code optimization. The parallelization of the TPS resulted in a speedup factor of 12 and 5.5 for the original version and the code optimized version, respectively. Hence the total speedup of the new implementation of the authors' TPS yielded speedup factors up to 55. Conclusions: The improved TPS is capable of completing treatment planning for ion beam therapy of a prostate irradiation considering organs at risk in this has been overseen in the review process. Also see below 6 min.

  15. Proposal of a truncated atomic beam fountain for reduction of collisional frequency shift

    SciTech Connect (OSTI)

    Takamizawa, A.; Yanagimachi, S.; Ikegami, T. [National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8563 (Japan); Shirakawa, Y. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda shi, Chiba 278-8510 (Japan)

    2010-07-15

    We propose an atomic fountain clock with a truncated cold atomic beam to achieve both a low collisional frequency shift and high frequency stability. In this clock, the launching velocity of a cold atomic beam can be swept to reduce the atomic density in the interrogation region for the Ramsey resonance and to increase the atomic density in the detection region. Before the top of the beam arrives at the interrogation region, the cold atomic beam is truncated by turning off the cooling laser beams to remove the unnecessary light shift. The atomic density in the interrogation region is theoretically evaluated to be 0.04 times that in an ordinary atomic fountain with optical molasses for the same number of detected atoms. The frequency stability limit due to quantum projection noise is calculated to reach 6.4x10{sup -14} in 1 s from the number of detected atoms while the fractional collisional shift is estimated to be {approx}{sup -}2x10{sup -16}.

  16. Neutral Beam Injection Experiments and Related Behavior of Neutral Particles in the GAMMA 10 Tandem Mirror

    SciTech Connect (OSTI)

    Nakashima, Y. [Plasma Research Center, University of Tsukuba (Japan); Watanabe, K. [Plasma Research Center, University of Tsukuba (Japan); Higashizono, Y. [Plasma Research Center, University of Tsukuba (Japan); Ohki, T. [Plasma Research Center, University of Tsukuba (Japan); Ogita, T. [Plasma Research Center, University of Tsukuba (Japan); Shoji, M. [National Institute for Fusion Science(Japan); Kobayashi, S. [Institute of Advanced Energy, Kyoto University (Japan); Islam, M.K. [Plasma Research Center, University of Tsukuba (Japan); Kubota, Y. [Plasma Research Center, University of Tsukuba (Japan); Yoshikawa, M. [Plasma Research Center, University of Tsukuba (Japan); Kobayashi, T. [Plasma Research Center, University of Tsukuba (Japan); Yamada, M. [Plasma Research Center, University of Tsukuba (Japan); Murakami, R. [Plasma Research Center, University of Tsukuba (Japan); Cho, T. [Plasma Research Center, University of Tsukuba (Japan)

    2005-01-15

    Results of neutral beam injection (NBI) experiments in the GAMMA 10 tandem mirror plasmas are presented together with the neutral particle behavior observed in the experiments. A hydrogen neural beam was injected into the hot-ion-mode plasmas by using the injector installed in the central-cell for the plasma heating and fueling. High-energy ions produced by NBI were observed and its energy distribution was measured for the first time with a neutral particle analyzer installed in the central-cell. The temporal and spatial behavior of hydrogen was observed with axially aligned H{sub {alpha}} detectors installed from the central midplane to anchor-cell. Enhancement of hydrogen recycling due to the beam injection and the cause of the observed decrease in plasma diamagnetism are discussed. The Monte-Carlo code DEGAS for neutral transport simulation was applied to the GAMMA 10 central-cell and a 3-dimensional simulation was performed in the NBI experiment. Localization of neutral particle during the beam injection is investigated based on the simulation and it was found that the increased recycling due to the beam injection was dominant near the injection port.

  17. Polarimetry of the polarized hydrogen deuteride HDice target under an electron beam

    SciTech Connect (OSTI)

    Laine, Vivien E.

    2013-10-01

    The study of the nucleon structure has been a major research focus in fundamental physics in the past decades and still is the main research line of the Thomas Jefferson National Accelerator Facility (Jefferson Lab). For this purpose and to obtain statistically meaningful results, having both a polarized beam and a highly efficient polarized target is essential. For the target, this means high polarization and high relative density of polarized material. A Hydrogen Deuteride (HD) target that presents both such characteristics has been developed first at Brookhaven National Lab (BNL) and brought to the Hall B of Jefferson Lab in 2008. The HD target has been shown to work successfully under a high intensity photon beam (BNL and Jefferson Lab). However, it remained to be seen if the target could stand an electron beam of reasonably high current (nA). In this perspective, the target was tested for the first time in its frozen spin mode under an electron beam at Jefferson Lab in 2012 during the g14 experiment. This dissertation presents the principles and usage procedures of this HD target. The polarimetry of this target with Nuclear Magnetic Resonance (NMR) during the electron beam tests is also discussed. In addition, this dissertation also describes another way to perform target polarimetry with the elastic scattering of electrons off a polarized target by using data taken on helium-3 during the E97-110 experiment that occurred in Jefferson Lab's Hall A in 2003.

  18. Ion source and beam guiding studies for an API neutron generator

    SciTech Connect (OSTI)

    Sy, A.; Ji, Q.; Persaud, A.; Ludewigt, B. A.; Schenkel, T.

    2013-04-19

    Recently developed neutron imaging methods require high neutron yields for fast imaging times and small beam widths for good imaging resolution. For ion sources with low current density to be viable for these types of imaging methods, large extraction apertures and beam focusing must be used. We present recent work on the optimization of a Penning-type ion source for neutron generator applications. Two multi-cusp magnet configurations have been tested and are shown to increase the extracted ion current density over operation without multi-cusp magnetic fields. The use of multi-cusp magnetic confinement and gold electrode surfaces have resulted in increased ion current density, up to 2.2 mA/cm{sup 2}. Passive beam focusing using tapered dielectric capillaries has been explored due to its potential for beam compression without the cost and complexity issues associated with active focusing elements. Initial results from first experiments indicate the possibility of beam compression. Further work is required to evaluate the viability of such focusing methods for associated particle imaging (API) systems.

  19. Condition for production of circulating proton beam with intensity greater than space charge limit.

    SciTech Connect (OSTI)

    Vadim Dudnikov

    2002-11-19

    Transverse e-p instability in proton rings could be damped by increasing the beam density and the rate of secondary particles production above the threshold level, with the corresponding decrease of unstable wavelength {lambda} below the transverse beam size h (increase of beam density n{sub b} and ion density n{sub i} above the threshold level: n{sub b} + n{sub i} > {beta}{sup 2}/(r{sub e} h{sup 2}), where r{sub e} = e{sup 2}/mc{sup 2}). Such island of stability can be reached by a fast charge-exchange injection without painting and enhanced generation of secondary plasma, which was demonstrated in a small scale Proton Storage Ring (PSR) at the Institute of Nuclear Physics, Novosibirsk, Russia. With successful damping of e-p instability, the intensity of circulating proton beam, with a space charge neutralization was increased up to 6 times above a space charge limit. Corresponding tune shift without space charge neutralization should be up to {Delta}v=0.85 x 6 (in the ring with v = 0.85). In this paper, they review experimental observations of transverse instability of proton beams in various rings. they also discuss methods which can be used to damp the instability. Such experimental data could be useful for verification of computer simulation tools developed for the studies of the space charge and instabilities in realistic conditions.

  20. Three-dimensional simulation of efficiency enhancement in free-electron laser with prebunched electron beam

    SciTech Connect (OSTI)

    Chitsazi, Mahboobeh; Maraghechi, B.; Rouhani, M. H.

    2010-10-15

    The effect of prebunching of the electron beam and tapering of the wiggler amplitude on the harmonic upconversion in free-electron laser amplifier is studied in three dimensions. A set of coupled nonlinear first-order differential equations that describe the three-dimensional simulation of the system is solved numerically. This set of equation describes self-consistently the longitudinal spatial dependence of radiation waists, curvatures, and amplitudes together with the evaluation of the electron beam. The analysis is related to extreme ultraviolet and x-ray emission. In addition to uniform beam, prebunched electron beam has also been studied. The effect of sinusoidal distribution of entry times for the electron beam on the evolution of radiation is compared with uniform distribution. It is shown that prebunching reduces the saturation length substantially. For efficiency enhancement, the wiggler is set to decrease linearly when the radiation of the third harmonic saturates. The optimum starting point and the slope of tapering of the amplitude of the wiggler are found by a successive run of the code. It was found that tapering can increase the saturated power of the third harmonic considerably.

  1. Whistler wave generation by non-gyrotropic, relativistic, electron beams

    SciTech Connect (OSTI)

    Skender, M.; Tsiklauri, D.

    2014-04-15

    Particle-in-cell code, EPOCH, is used for studying features of the wave component evident to propagate backwards from the front of the non-gyrotropic, relativistic beam of electrons injected in the Maxwellian, magnetised background plasma with decreasing density profile. According to recent findings presented in Tsiklauri [Phys. Plasmas 18, 052903 (2011)], Schmitz and Tsiklauri [Phys. Plasmas 20, 062903 (2013)], and Pechhacker and Tsiklauri [Phys. Plasmas 19, 112903 (2012)], in a 1.5-dimensional magnetised plasma system, the non-gyrotropic beam generates freely escaping electromagnetic radiation with properties similar to the Type-III solar radio bursts. In this study, the backwards propagating wave component evident in the perpendicular components of the electromagnetic field in such a system is presented for the first time. Background magnetic field strength in the system is varied in order to prove that the backwards propagating wave's frequency, prescribed by the whistler wave dispersion relation, is proportional to the specified magnetic field. Moreover, the identified whistlers are shown to be generated by the normal Doppler-shifted relativistic resonance. Large fraction of the energy of the perpendicular electromagnetic field components is found to be carried away by the whistler waves, while a small but sufficient fraction is going into L- and R-electromagnetic modes.

  2. Beam spoiling a reflector antenna with conducting shim. (Technical...

    Office of Scientific and Technical Information (OSTI)

    Beam spoiling a reflector antenna with conducting shim. Citation Details In-Document Search Title: Beam spoiling a reflector antenna with conducting shim. A horn-fed dish reflector...

  3. Electron beam directed energy device and methods of using same

    DOE Patents [OSTI]

    Retsky, Michael W. (Trumbull, CT)

    2007-10-16

    A method and apparatus is disclosed for an electron beam directed energy device. The device consists of an electron gun with one or more electron beams. The device includes one or more accelerating plates with holes aligned for beam passage. The plates may be flat or preferably shaped to direct each electron beam to exit the electron gun at a predetermined orientation. In one preferred application, the device is located in outer space with individual beams that are directed to focus at a distant target to be used to impact and destroy missiles. The aimings of the separate beams are designed to overcome Coulomb repulsion. A method is also presented for directing the beams to a target considering the variable terrestrial magnetic field. In another preferred application, the electron beam is directed into the ground to produce a subsurface x-ray source to locate and/or destroy buried or otherwise hidden objects including explosive devices.

  4. Summary of the 2014 Beam-Halo Monitoring Workshop (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Summary of the 2014 Beam-Halo Monitoring Workshop Citation Details In-Document Search Title: Summary of the 2014 Beam-Halo Monitoring Workshop Authors: Fisher, Alan S ;...

  5. Summary of the 2014 Beam-Halo Monitoring Workshop (Conference...

    Office of Scientific and Technical Information (OSTI)

    Conference: Summary of the 2014 Beam-Halo Monitoring Workshop Citation Details In-Document Search Title: Summary of the 2014 Beam-Halo Monitoring Workshop You are accessing a...

  6. A Neutral Beam Pole Shield with Copper Plates and Serviceable...

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

    A Neutral Beam Pole Shield with Copper Plates and Serviceable Molybdenum Inserts The copper pole shields for the neutral beam lines that have been in service at DIII-D have...

  7. Temescal BJD-1800 E-Beam Deposition system

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

    steps. Capabilities: Maximum output power of 10kW and a emission voltage of 4-10kV E-beam deflection of 270 degrees Permanent magnet Lateral and longitudinal beam sweep...

  8. SSRL Beam Lines by Technique | Stanford Synchrotron Radiation...

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

    Beam Lines by Number | SPEAR3 Parameters Supported Technique(s) Beam Line X-ray Absorption Spectroscopy Biological x-ray absorption spectroscopy 2-2, 4-3, 7-3, 9-3, 14-3...

  9. Axial and transverse acoustic radiation forces on a fluid sphere placed arbitrarily in Bessel beam standing wave tweezers

    SciTech Connect (OSTI)

    Mitri, F.G.

    2014-03-15

    The axial and transverse radiation forces on a fluid sphere placed arbitrarily in the acoustical field of Bessel beams of standing waves are evaluated. The three-dimensional components of the time-averaged force are expressed in terms of the beam-shape coefficients of the incident field and the scattering coefficients of the fluid sphere using a partial-wave expansion (PWE) method. Examples are chosen for which the standing wave field is composed of either a zero-order (non-vortex) Bessel beam, or a first-order Bessel vortex beam. It is shown here, that both transverse and axial forces can push or pull the fluid sphere to an equilibrium position depending on the chosen size parameter ka (where k is the wave-number and a the spheres radius). The corresponding results are of particular importance in biophysical applications for the design of lab-on-chip devices operating with Bessel beams standing wave tweezers. Moreover, potential investigations in acoustic levitation and related applications in particle rotation in a vortex beam may benefit from the results of this study. -- Highlights: The axial and transverse forces on a fluid sphere in acoustical Bessel beams tweezers are evaluated. The attraction or repulsion to an equilibrium position in the standing wave field is examined. Potential applications are in particle manipulation using standing waves.

  10. Vector processing enhancements for real-time image analysis.

    SciTech Connect (OSTI)

    Shoaf, S.; APS Engineering Support Division

    2008-01-01

    A real-time image analysis system was developed for beam imaging diagnostics. An Apple Power Mac G5 with an Active Silicon LFG frame grabber was used to capture video images that were processed and analyzed. Software routines were created to utilize vector-processing hardware to reduce the time to process images as compared to conventional methods. These improvements allow for more advanced image processing diagnostics to be performed in real time.

  11. Tailored Terahertz Pulses from a Laser-Modulated Electron Beam

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

    Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Tailored Terahertz Pulses from a Laser-Modulated Electron Beam Print Wednesday, 29 November 2006 00:00 Researchers at the ALS have demonstrated a new method to generate tunable, coherent, broadband terahertz radiation from a relativistic electron beam modulated by a femtosecond laser. Interaction of the ALS electron beam with a femtosecond laser pulse as they co-propagate through a wiggler modulates the electron energies within a

  12. Jefferson Lab electron beam charges up (Inside Business) | Jefferson Lab

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

    https://www.jlab.org/news/releases/jefferson-lab-electron-beam-charges Submitted: Friday, October 24, 2008

  13. PROTON BEAM REQUIREMENTS FOR A NEUTRINO FACTORY AND MUON COLLIDER

    SciTech Connect (OSTI)

    Zisman, Michael S.

    2009-12-11

    Both a Neutrino Factory and a Muon Collider place stringent demands on the proton beam used to generate the desired beam of muons. Here we discuss the advantages and challenges of muon accelerators and the rationale behind the requirements on proton beam energy, intensity, bunch length, and repetition rate. Example proton driver configurations that have been considered in recent years are also briefly indicated.

  14. Laser diagnostic for high current H{sup -} beams

    SciTech Connect (OSTI)

    Shafer, Robert E.

    1998-12-10

    In the last 5 years, significant technology advances have been made in the performance, size, and cost of solid-state diode-pumped lasers. These developments enable the use of compact Q-switched Nd:YAG lasers as a beam diagnostic for high current H{sup -} beams. Because the threshold for photodetachment is only 0.75 eV, and the maximum detachment cross section is 4x10{sup -17} cm{sup 2} at 1.5 eV, A 50 mJ/pulse Q-switched Nd:YAG laser can neutralize a significant fraction of the beam in a single 10 ns wide pulse. The neutral beam maintains nearly identical parameters as the parent H{sup -} beam, including size, divergence, energy, energy spread, and phase spread. A dipole magnet can separate the neutral beam from the H{sup -} beam to allow diagnostics on the neutral beam without intercepting the high-current H{sup -} beam. Such a laser system can also be used to extract a low current proton beam, or to induce fluorescence in partially stripped heavy ion beams. Possible beamline diagnostic systems will be reviewed, and the neutral beam yields will be calculated.

  15. High-gradient two-beam electron accelerator

    SciTech Connect (OSTI)

    Hirshfield, Jay L.

    2014-11-04

    The main goal for this project was to design, build, and evaluate a detuned-cavity, collinear, two-beam accelerator structure. Testing was to be at the Yale University Beam Physics Laboratory, under terms of a sub-grant from Omega-P to Yale. Facilities available at Yale for this project include a 6-MeV S-band RF gun and associated beam line for forming and transporting a ~1 A drive beam , a 300 kV beam source for use as a test beam, and a full panoply of laboratory infrastructure and test equipment. During the first year of this project, availability and functionality of the 6-MeV drive beam and 300 kV test beam were confirmed, and the beam line was restored to a layout to be used with the two-beam accelerator project. Major efforts during the first year were also focused on computational design and simulation of the accelerator structure itself, on beam dynamics, and on beam transport. Effort during the second year was focussed on building and preparing to test the structure, including extensive cold testing. Detailed results from work under this project have been published in twelve archival journal articles, listed in Section IV of the technical report.

  16. Beams 92: Proceedings. Volume 1: Invited papers, pulsed power

    SciTech Connect (OSTI)

    Mosher, D.; Cooperstein, G.

    1993-12-31

    This report contains papers on the following topics: Ion beam papers; electron beam, bremsstrahlung, and diagnostics papers; radiating Z- pinch papers; microwave papers; electron laser papers; advanced accelerator papers; beam and pulsed power applications papers; pulsed power papers; and these papers have been indexed separately elsewhere.

  17. Top 8 Things You Didn't Know About Daylight Saving Time | Department...

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

    ... increasing the energy of laser beams as they make their way toward the target chamber. NIF recently achieved a 500 terawatt shot - 1,000 times more power than the United States ...

  18. Methods for assisting recovery of damaged brain and spinal cord using arrays of X-ray microplanar beams

    DOE Patents [OSTI]

    Dilmanian, F. Avraham; McDonald, III, John W.

    2007-01-02

    A method of assisting recovery of an injury site of brain or spinal cord injury includes providing a therapeutic dose of X-ray radiation to the injury site through an array of parallel microplanar beams. The dose at least temporarily removes regeneration inhibitors from the irradiated regions. Substantially unirradiated cells surviving between the microplanar beams migrate to the in-beam irradiated portion and assist in recovery. The dose may be administered in dose fractions over several sessions, separated in time, using angle-variable intersecting microbeam arrays (AVIMA). Additional doses may be administered by varying the orientation of the microplanar beams. The method may be enhanced by injecting stem cells into the injury site.

  19. Methods for assisting recovery of damaged brain and spinal cord using arrays of X-Ray microplanar beams

    DOE Patents [OSTI]

    Dilmanian, F. Avraham; McDonald, III, John W.

    2007-12-04

    A method of assisting recovery of an injury site of brain or spinal cord injury includes providing a therapeutic dose of X-ray radiation to the injury site through an array of parallel microplanar beams. The dose at least temporarily removes regeneration inhibitors from the irradiated regions. Substantially unirradiated cells surviving between the microplanar beams migrate to the in-beam irradiated portion and assist in recovery. The dose may be administered in dose fractions over several sessions, separated in time, using angle-variable intersecting microbeam arrays (AVIMA). Additional doses may be administered by varying the orientation of the microplanar beams. The method may be enhanced by injecting stem cells into the injury site.

  20. Experiments on LHC long-range beam-beam compensation and crossing schemes at the CERN SPS in 2004

    SciTech Connect (OSTI)

    Zimmermann, F.; Koutchouk, J.-P.; Roncarolo, F.; Wenninger, J.; Sen, T.; Shiltsev, V.; Papaphilippou, Y.; /ESRF, Grenoble

    2005-05-01

    Experiments with two prototype long-range beam-beam compensators (current-carrying wires) during the 2004 CERN SPS run explored the efficiency of a proposed long-range beam-beam compensation for the LHC. In addition, the SPS compensators were also used to ''simulate'' the effect of different planes of crossing at two LHC interaction points. We present the experimental results and compare them with computer simulations.