Sample records for latitude tilt irradiance

  1. The Tilt Intonation Model 

    E-Print Network [OSTI]

    Taylor, Paul

    The tilt intonation model facilitates automatic analysis and synthesis of intonation. The analysis algorithm detects intonational events in F0 contours and parameterises them in terms of the continuously varying parameters. ...

  2. Tilted-mirror semiconductor lasers

    SciTech Connect (OSTI)

    Salzman, J.; Lang, R.; Margalit, S.; Yariv, A.

    1985-07-01T23:59:59.000Z

    Broad-area GaAs heterostructure lasers with a tilted mirror were demonstrated for the first time, with the tilted mirror fabricated by etching. These lasers operate in a smooth and stable single lateral mode with a high degree of spatial coherence. The suppression of filamentation manifests itself in a high degree of reproducibility in the near-field pattern.

  3. Fluid observers and tilting cosmology

    E-Print Network [OSTI]

    A. A. Coley; S. Hervik; W. C. Lim

    2006-05-24T23:59:59.000Z

    We study perfect fluid cosmological models with a constant equation of state parameter $\\gamma$ in which there are two naturally defined time-like congruences, a geometrically defined geodesic congruence and a non-geodesic fluid congruence. We establish an appropriate set of boost formulae relating the physical variables, and consequently the observed quantities, in the two frames. We study expanding spatially homogeneous tilted perfect fluid models, with an emphasis on future evolution with extreme tilt. We show that for ultra-radiative equations of state (i.e., $\\gamma>4/3$), generically the tilt becomes extreme at late times and the fluid observers will reach infinite expansion within a finite proper time and experience a singularity similar to that of the big rip. In addition, we show that for sub-radiative equations of state (i.e., $\\gamma < 4/3$), the tilt can become extreme at late times and give rise to an effective quintessential equation of state. To establish the connection with phantom cosmology and quintessence, we calculate the effective equation of state in the models under consideration and we determine the future asymptotic behaviour of the tilting models in the fluid frame variables using the boost formulae. We also discuss spatially inhomogeneous models and tilting spatially homogeneous models with a cosmological constant.

  4. TILT STABILITY, UNIFORM QUADRATIC GROWTH, AND STRONG ...

    E-Print Network [OSTI]

    2012-05-08T23:59:59.000Z

    Tilt stability, variational analysis, subdifferentials, quadratic growth, strong metric .... Some convex analysis. ..... Example 3.5 (Failure of subdifferential continuity).

  5. Notes 16. Analysis of tilting pad bearings

    E-Print Network [OSTI]

    San Andres, Luis

    2010-01-01T23:59:59.000Z

    NOTES 16. STATIC AND DYNAMIC FORCED PERFORMANCE OF TILTING PAD BEARINGS: ANALYSIS INCLUDING PIVOT STIFFNESS Dr. Luis San Andr?s Mast-Childs Professor August 2010 SUMMARY Work in progress ? still a lot of be done Introduction... Figure 1 shows a tilting pad journal bearing comprised of four pads. Each pad tilts about its pivot making a hydrodynamic film that generates a pressure reacting to the static load applied on the spinning journal. This type of bearing is typically...

  6. Large optics inspection, tilting, and washing stand

    DOE Patents [OSTI]

    Ayers, Marion Jay; Ayers, Shannon Lee

    2012-10-09T23:59:59.000Z

    A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

  7. Large optics inspection, tilting, and washing stand

    DOE Patents [OSTI]

    Ayers, Marion Jay (Brentwood, CA); Ayers, Shannon Lee (Brentwood, CA)

    2010-08-24T23:59:59.000Z

    A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

  8. Solar: monthly latitude tilt GIS data at 40km resolution for...

    Open Energy Info (EERE)

    potential for the data domain. The insolation values represent the average solar energy available to a flat plate collector, such as a photovoltaic panel, oriented due south...

  9. 3, 10811107, 2003 Mid-latitude ozone

    E-Print Network [OSTI]

    Boyer, Edmond

    ACPD 3, 1081­1107, 2003 Mid-latitude ozone changes in a 3D CTM M. P. Chipperfield Title Page-dimensional model study of long-term mid-high latitude lower stratosphere ozone changes M. P. Chipperfield School­1107, 2003 Mid-latitude ozone changes in a 3D CTM M. P. Chipperfield Title Page Abstract Introduction

  10. Combined Scanning Transmission Electron Microscopy Tilt- and Focal Series

    SciTech Connect (OSTI)

    Dahmen, Tim [German Research Center for Artificial Intelligence (DFKI), Germany] [German Research Center for Artificial Intelligence (DFKI), Germany; Baudoin, Jean-Pierre G [ORNL] [ORNL; Lupini, Andrew R [ORNL] [ORNL; Kubel, Christian [Karlsruhe Institute of Technology, Leopoldshafen, Germany] [Karlsruhe Institute of Technology, Leopoldshafen, Germany; Slusallek, Phillip [German Research Center for Artificial Intelligence (DFKI), Germany] [German Research Center for Artificial Intelligence (DFKI), Germany; De Jonge, Niels [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    In this study, a combined tilt- and focal series is proposed as a new recording scheme for high-angle annular dark-field scanning transmission electron microscopy (STEM) tomography. Three-dimensional (3D) data were acquired by mechanically tilting the specimen, and recording a through-focal series at each tilt direction. The sample was a whole-mount macrophage cell with embedded gold nanoparticles. The tilt focal algebraic reconstruction technique (TF-ART) is introduced as a new algorithm to reconstruct tomograms from such combined tilt- and focal series. The feasibility of TF-ART was demonstrated by 3D reconstruction of the experimental 3D data. The results were compared with a conventional STEM tilt series of a similar sample. The combined tilt- and focal series led to smaller missing wedge artifacts, and a higher axial resolution than obtained for the STEM tilt series, thus improving on one of the main issues of tilt series-based electron tomography.

  11. Tilt assembly for tracking solar collector assembly

    DOE Patents [OSTI]

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24T23:59:59.000Z

    A tilt assembly is used with a solar collector assembly of the type comprising a frame, supporting a solar collector, for movement about a tilt axis by pivoting a drive element between first and second orientations. The tilt assembly comprises a drive element coupler connected to the drive element and a driver, the driver comprising a drive frame, a drive arm and a drive arm driver. The drive arm is mounted to the drive frame for pivotal movement about a drive arm axis. Movement on the drive arm mimics movement of the drive element. Drive element couplers can extend in opposite directions from the outer portion of the drive arm, whereby the assembly can be used between adjacent solar collector assemblies in a row of solar collector assemblies.

  12. The cost of noise reduction in commercial tilt rotor aircraft

    E-Print Network [OSTI]

    Faulkner, Henry B.

    1974-01-01T23:59:59.000Z

    The relationship between direct operating cost and departure noise annoyance was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various ...

  13. Ram pressure stripping of tilted galaxies

    E-Print Network [OSTI]

    Jachym, P; Palous, J; Combes, F

    2009-01-01T23:59:59.000Z

    Ram pressure stripping of galaxies in clusters can yield gas deficient disks. Previous numerical simulations based on various approaches suggested that, except for near edge-on disk orientations, the amount of stripping depends very little on the inclination angle. Following our previous study of face-on stripping, we extend the set of parameters with the disk tilt angle and explore in detail the effects of the ram pressure on the interstellar content (ISM) of tilted galaxies that orbit in various environments of clusters, with compact or extended distributions of the intra-cluster medium (ICM). We further study how results of numerical simulations could be estimated analytically. A grid of numerical simulations with varying parameters is produced using the tree/SPH code GADGET with a modified method for calculating the ISM-ICM interaction. These SPH calculations extend the set of existing results obtained from different codes using various numerical techniques. The simulations confirm the general trend of le...

  14. Prediction of tilted capillary barrier performance

    SciTech Connect (OSTI)

    Webb, S.W.; McCord, J.T.; Dwyer, S.F.

    1997-04-01T23:59:59.000Z

    Capillary barriers, consisting of tilted fine-over-coarse layers under unsaturated conditions, have been suggested as landfill covers to divert water infiltration away from sensitive underground regions, especially for arid and semi-arid regions. The Hydrological Evaluation of Landfill Performance (HELP) computer code is an evaluation tool for landfill covers used by designers and regulators. HELP is a quasi-two-dimensional model that predicts moisture movement into and through the underground soil and waste layers. Processes modeled within HELP include precipitation, runoff, evapotranspiration, unsaturated vertical drainage, saturated lateral drainage, and leakage through liners. Unfortunately, multidimensional unsaturated flow phenomena that are necessary for evaluating tilted capillary barriers are not included in HELP. Differences between the predictions of the HELP and those from a multidimensional unsaturated flow code are presented to assess the two different approaches. Comparisons are presented for the landfill covers including capillary barrier configurations at the Alternative Landfill Cover Demonstration (ALCD) being conducted at Sandia.

  15. Stabilizing windings for tilting and shifting modes

    DOE Patents [OSTI]

    Jardin, Stephen C. (Princeton, NJ); Christensen, Uffe R. (Princeton, NJ)

    1984-01-01T23:59:59.000Z

    This invention relates to passive conducting loops for stabilizing a plasma ring against unstable tilting and/or shifting modes. To this end, for example, plasma ring in a spheromak is stabilized by a set of four figure-8 shaped loops having one pair on one side of the plasma and one pair on the other side with each pair comprising two loops whose axes are transverse to each other.

  16. ULTRAVIOLET EXTINCTION AT HIGH GALACTIC LATITUDES

    SciTech Connect (OSTI)

    Peek, J. E. G.; Schiminovich, David, E-mail: jegpeek@gmail.com [Department of Astronomy, Columbia University, New York, NY (United States)

    2013-07-01T23:59:59.000Z

    In order to study the properties and effects of high Galactic latitude dust, we present an analysis of 373,303 galaxies selected from the Galaxy Evolution Explorer All-Sky Survey and Wide-field Infrared Explorer All-Sky Data Release. By examining the variation in aggregate ultraviolet colors and number density of these galaxies, we measure the extinction curve at high latitude. We additionally consider a population of spectroscopically selected galaxies from the Sloan Digital Sky Survey to measure extinction in the optical. We find that dust at high latitude is neither quantitatively nor qualitatively consistent with standard reddening laws. Extinction in the FUV and NUV is {approx}10% and {approx}35% higher than expected, with significant variation across the sky. We find that no single R{sub V} parameter fits both the optical and ultraviolet extinction at high latitude, and that while both show detectable variation across the sky, these variations are not related. We propose that the overall trends we detect likely stem from an increase in very small silicate grains in the interstellar medium.

  17. Summertime total ozone variations over middle and polar latitudes

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Summertime total ozone variations over middle and polar latitudes 1234567 89A64BC7DEF72B4 467342 $7D425BE27B725CE9393BE647 #12;Summertime total ozone variations over middle and polar latitudes and summertime ozone over middle and polar latitudes is analyzed using zonally averaged total ozone data. Short

  18. Analysis and synthesis of intonation using the tilt model 

    E-Print Network [OSTI]

    Taylor, Paul

    This paper introduces the Tilt intonational model and describes how this model can be used to automatically analyze and synthesize intonation. In the model, intonation is represented as a linear sequence of events, which ...

  19. Geometric Model of a Narrow Tilting CAR using Robotics formalism

    E-Print Network [OSTI]

    Boyer, Edmond

    of an Electrical narrow tilting car instead of a large gasoline car should dramatically decrease traffic congestion are the terminal links. Each body Cj is connected to its antecedent Ci (i=a (j)) with a joint that represents

  20. A Neural Network Model of Visual Tilt Aftereffects

    E-Print Network [OSTI]

    1997-01-01T23:59:59.000Z

    RF-LISSOM, a self-organizing model of laterally connected orientation maps in the primary visual cortex, was used to study the psychological phenomenon known as the tilt aftereffect. The same self-organizing processes that are responsible for the long-term development of the map and its lateral connections are shown to result in tilt aftereffects over short time scales in the adult. The model allows observing large numbers of neurons and connections simultaneously, making it possible to relate higher-level phenomenato low-level events, which is difficult to do experimentally. The results give computational support for the idea that direct tilt aftereffects arise from adaptive lateral interactions between feature detectors, as has long been surmised. They also suggest that indirect effects could result from the conservation of synaptic resourcesduring this process. The model thus provides a unified computational explanation of self-organization and both direct and indirect tilt aftereff...

  1. TILT POUR TRIALS AND ANALYSIS Bob Bryant1

    E-Print Network [OSTI]

    Beckermann, Christoph

    TILT POUR TRIALS AND ANALYSIS Bob Bryant1 , Kent D. Carlson2 , Shouzhu Ou2 , Christoph Beckermann2 reduce inclusion severity, compared to standard techniques. Bryant, R., Carlson, K.D., Ou, S

  2. Revisiting the question: Does high-latitude solar activity lead low-latitude solar activity in time phase?

    SciTech Connect (OSTI)

    Kong, D. F.; Qu, Z. N. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Guo, Q. L., E-mail: kdf@ynao.ac.cn [College of Mathematics Physics and Information Engineering, Jiaxing University, Jiaxing 314001 (China)

    2014-05-01T23:59:59.000Z

    Cross-correlation analysis and wavelet transform methods are used to investigate whether high-latitude solar activity leads low-latitude solar activity in time phase or not, using the data of the Carte Synoptique solar filaments archive from 1919 March to 1989 December. From the cross-correlation analysis, high-latitude solar filaments have a time lead of 12 Carrington solar rotations with respect to low-latitude ones. Both the cross-wavelet transform and wavelet coherence indicate that high-latitude solar filaments lead low-latitude ones in time phase. Furthermore, low-latitude solar activity is better correlated with high-latitude solar activity of the previous cycle than with that of the following cycle, which is statistically significant. Thus, the present study confirms that high-latitude solar activity in the polar regions is indeed better correlated with the low-latitude solar activity of the following cycle than with that of the previous cycle, namely, leading in time phase.

  3. Laser Guide Star Adaptive Optics without Tip-tilt

    E-Print Network [OSTI]

    R. Davies; S. Rabien; C. Lidman; M. Le Louarn; M. Kasper; N. M. Forster Schreiber; V. Roccatagliata; N. Ageorges; P. Amico; C. Dumas; F. Mannucci

    2008-01-24T23:59:59.000Z

    Adaptive optics (AO) systems allow a telescope to reach its diffraction limit at near infrared wavelengths. But to achieve this, a bright natural guide star (NGS) is needed for the wavefront sensing, severely limiting the fraction of the sky over which AO can be used. To some extent this can be overcome with a laser guide star (LGS). While the laser can be pointed anywhere in the sky, one still needs to have a natural star, albeit fainter, reasonably close to correct the image motion (tip-tilt) to which laser guide stars are insensitive. There are in fact many astronomical targets without suitable tip-tilt stars, but for which the enhanced resolution obtained with the Laser Guide Star Facility (LGSF) would still be very beneficial. This article explores what adaptive optics performance one might expect if one dispenses with the tip-tilt star, and in what situations this mode of observing might be needed.

  4. Method to fabricate a tilted logpile photonic crystal

    DOE Patents [OSTI]

    Williams, John D. (Albuquerque, NM); Sweatt, William C. (Albuquerque, NM)

    2010-10-26T23:59:59.000Z

    A method to fabricate a tilted logpile photonic crystal requires only two lithographic exposures and does not require mask repositioning between exposures. The mask and photoresist-coated substrate are spaced a fixed and constant distance apart using a spacer and the stack is clamped together. The stack is then tilted at a crystallographic symmetry angle (e.g., 45 degrees) relative to the X-ray beam and rotated about the surface normal until the mask is aligned with the X-ray beam. The stack is then rotated in plane by a small stitching angle and exposed to the X-ray beam to pattern the first half of the structure. The stack is then rotated by 180.degree. about the normal and a second exposure patterns the remaining half of the structure. The method can use commercially available DXRL scanner technology and LIGA processes to fabricate large-area, high-quality tilted logpile photonic crystals.

  5. Tilted accretion discs in cataclysmic variables: tidal instabilities and superhumps

    E-Print Network [OSTI]

    J. R. Murray; P. J. Armitage

    1998-09-10T23:59:59.000Z

    We investigate the growth of tidal instabilities in accretion discs in a binary star potential, using three dimensional numerical simulations. As expected from analytic work, the disc is prone to an eccentric instability provided that it is large enough to extend to the 3:1 resonance. The eccentric disc leads to positive superhumps in the light curve. It has been proposed that negative superhumps might arise from a tilted disc, but we find no evidence that the companion gravitational tilt instability can grow fast enough in a fluid disc to create a measurable inclination. The origin of negative superhumps in the light curves of cataclysmic variables remains a puzzle.

  6. Rotordynamic and thermal analyses of compliant flexure pivot tilting pad gas bearings

    E-Print Network [OSTI]

    Sim, Kyu-Ho

    2009-05-15T23:59:59.000Z

    Rotordynamic and thermal analyses of compliant flexure pivot tilting pad gas bearings were performed. First, compliant flexure pivot tilting pad gas bearings with pad radial compliance (CFTPBs) were introduced and designed for high-speed oil...

  7. The cost of noise reduction for departure and arrival operations of commercial tilt rotor aircraft

    E-Print Network [OSTI]

    Faulkner, Henry B.

    1976-01-01T23:59:59.000Z

    The relationship between direct operating cost (DOC) and noise annoyance due to a departure and an arrival operation was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt ...

  8. A new southern high-latitude index P. Ballatore1

    E-Print Network [OSTI]

    Boyer, Edmond

    -aligned currents at the poleward auroral rim both in¯uence geomagnetic perturbations at polar latitudes and feed a new regional geomagnetic index AES-80, de®ned similarly to the classical auroral electrojet AE index, using data from ®ve Antarctic stations located at corrected geomagnetic latitudes about 80 °S. Because

  9. Temporal variations of solar rotation rate at high latitudes

    E-Print Network [OSTI]

    H. M. Antia; Sarbani Basu

    2001-08-14T23:59:59.000Z

    Frequency splitting coefficients from Global Oscillation Network Group (GONG) and Michelson Doppler Imager (MDI) observations covering the period 1995--2001 are used to study temporal variations in the solar rotation rate at high latitudes. The torsional oscillation pattern in the Sun is known to penetrate to a depth of about $0.1R_\\odot$ with alternate bands of faster and slower rotating plasma. At lower latitudes the bands move towards equator with time. At higher latitudes, however, the bands appear to move towards the poles. This is similar to the observed pole-ward movement of large scale magnetic fields at high latitudes. This also supports theoretical results of pole-ward moving bands at high latitudes in some mean field dynamo models. The polar rotation rate is found to decrease between 1995 and 1999 after which it has started increasing.

  10. On the first Hochschild cohomology group of a cluster-tilted algebra

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    On the first Hochschild cohomology group of a cluster-tilted algebra Ibrahim Assem, Mar´ia Julia Redondo and Ralf Schiffler Abstract Given a cluster-tilted algebra B, we study its first Hochschild cohomol- ogy group HH1 (B) with coefficients in the B-B-bimodule B. If C is a tilted algebra such that B

  11. IRRADIATION EXPERIMENTS &

    E-Print Network [OSTI]

    McDonald, Kirk

    IRRADIATION EXPERIMENTS & FACILITIES AT BNL: BLIP & NSLS II Peter Wanderer Superconducting Magnet). Current user: LBNE ­ materials for Project X. · Long Baseline Neutrino Experiment ­ Abandoned gold mine

  12. EIS-0039: Motor Gasoline Deregulation and the Gasoline Tilt

    Broader source: Energy.gov [DOE]

    The Economic Regulatory Administration developed this EIS to evaluate the environmental impacts, including social and economic impacts, that may result from either of two proposed regulatory changes: (1) the exemption of motor gasoline from the Department of Energy's Mandatory Petroleum Price and Allocation Regulations, and (2) the adoption of the gasoline tilt, a proposed regulation that would allow refiners to recover an additional amount of their total increased costs on gasoline.

  13. Splay and tilt energy of bipolar lipid membranes

    E-Print Network [OSTI]

    Timur R. Galimzyanov; Peter I. Kuzmin; Peter Pohl; Sergey A. Akimov

    2014-12-28T23:59:59.000Z

    Archaea organisms are able to survive in extremely aggressive environment. It is thought that such resistance, at least, in part is sustained by unique properties of archaea membrane. The membrane consists of so called bolalipids, which has two polar heads joined by two hydrocarbon chains. Thus bolalipids can exist in two conformations: i) polar heads are located at different sides of bolalipid layer, so called, O-shape; ii) polar heads are located at the same side of the layer, so called, U-shape. Both polar heads and chains are chemically different from those for conventional lipids. In the present study we develop basis for theory of elasticity of bolalipid membranes. Deformations of splay, tilt and Gaussian curvature are considered. We show that energetic contributions of tilt deformation from two surfaces of bolalipid layer are additive, as well as Gaussian curvature, while splay deformations yield a cross-term. The presence of U-shapes is taken into account in terms of the layer spontaneous curvature. Estimation of tilt modulus and possible experiments allowing to measure splay moduli are described.

  14. Tilting the Primordial Power Spectrum with Bulk Viscosity

    E-Print Network [OSTI]

    James E. Lidsey

    1993-12-16T23:59:59.000Z

    Within the context of the cold dark matter model, current observations suggest that inflationary models which generate a tilted primordial power spectrum with negligible gravitational waves provide the most promising mechanism for explaining large scale clustering. The general form of the inflationary potential which produces such a spectrum is a hyperbolic function and is interpreted physically as a bulk viscous stress contribution to the energy-momentum of a perfect baryotropic fluid. This is equivalent to expanding the equation of state as a truncated Taylor series. Particle physics models which lead to such a potential are discussed.

  15. The effects of gantry tilt on breast dose and image noise in cardiac CT

    SciTech Connect (OSTI)

    Hoppe, Michael E.; Gandhi, Diksha; Schmidt, Taly Gilat [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States)] [Department of Biomedical Engineering, Marquette University, Milwaukee, Wisconsin 53233 (United States); Stevens, Grant M. [GE Healthcare, Waukesha, Wisconsin 53188 (United States)] [GE Healthcare, Waukesha, Wisconsin 53188 (United States); Foley, W. Dennis [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)] [Department of Radiology, Medical College of Wisconsin, Froedtert Memorial Lutheran Hospital, Milwaukee, Wisconsin 53226 (United States)

    2013-12-15T23:59:59.000Z

    Purpose: This study investigated the effects of tilted-gantry acquisition on image noise and glandular breast dose in females during cardiac computed tomography (CT) scans. Reducing the dose to glandular breast tissue is important due to its high radiosensitivity and limited diagnostic significance in cardiac CT scans.Methods: Tilted-gantry acquisition was investigated through computer simulations and experimental measurements. Upon IRB approval, eight voxelized phantoms were constructed from previously acquired cardiac CT datasets. Monte Carlo simulations quantified the dose deposited in glandular breast tissue over a range of tilt angles. The effects of tilted-gantry acquisition on breast dose were measured on a clinical CT scanner (CT750HD, GE Healthcare) using an anthropomorphic phantom with MOSFET dosimeters in the breast regions. In both simulations and experiments, scans were performed at gantry tilt angles of 0°–30°, in 5° increments. The percent change in breast dose was calculated relative to the nontilted scan for all tilt angles. The percent change in noise standard deviation due to gantry tilt was calculated in all reconstructed simulated and experimental images.Results: Tilting the gantry reduced the breast dose in all simulated and experimental phantoms, with generally greater dose reduction at increased gantry tilts. For example, at 30° gantry tilt, the dosimeters located in the superior, middle, and inferior breast regions measured dose reductions of 74%, 61%, and 9%, respectively. The simulations estimated 0%–30% total breast dose reduction across the eight phantoms and range of tilt angles. However, tilted-gantry acquisition also increased the noise standard deviation in the simulated phantoms by 2%–50% due to increased pathlength through the iodine-filled heart. The experimental phantom, which did not contain iodine in the blood, demonstrated decreased breast dose and decreased noise at all gantry tilt angles.Conclusions: Tilting the gantry reduced the dose to the breast, while also increasing noise standard deviation. Overall, the noise increase outweighed the dose reduction for the eight voxelized phantoms, suggesting that tilted gantry acquisition may not be beneficial for reducing breast dose while maintaining image quality.

  16. Evolution of the contact network during tilting cycles of a granular pile under gravity

    E-Print Network [OSTI]

    Staron, Lydie

    Evolution of the contact network during tilting cycles of a granular pile under gravity S. Deboeuf of a granular pile undergoing quasi-static tilting cycles in the gravity field. The volumic deformation of granular piles during continuous load in the gravity field (Staron, Vilotte, & Radjai 2002). Far before

  17. Escape configuration lattice near the nematic-isotropic transition: Tilt analogue of blue phases

    E-Print Network [OSTI]

    Buddhapriya Chakrabarti; Yashodhan Hatwalne; N. V. Madhusudana

    2006-04-28T23:59:59.000Z

    We predict the possible existence of a new phase of liquid crystals near the nematic-isotropic ($ NI $) transition. This phase is an achiral, tilt-analogue of the blue phase and is composed of a lattice of {\\em double-tilt}, escape-configuration cylinders. We discuss the structure and the stability of this phase and provide an estimate of the lattice parameter.

  18. Self-Optimization of Antenna Tilt and Pilot Power for Dedicated Channels

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Self-Optimization of Antenna Tilt and Pilot Power for Dedicated Channels Abstract-- In Radio Access Networks (RAN), fixed configurations result in poor network efficiency. This sub- optimal performance present a framework for a self-optimizing RAN, which adapts Antenna Tilt and Pilot Power according

  19. Conjugate High Latitude Measurements along the 40 Magnetic Meridian

    E-Print Network [OSTI]

    Michigan, University of

    ­ 12 Volt system · Six 40 Wae Solar Panels · Sixteen 100 Ah AGM sealed leadConjugate High Latitude Measurements along the 40º Magnetic Meridian: Autonomous Adaptive Low-Power the 2014 season marked as red squares. #12;Autonomous Adaptive Low-Power Instrument

  20. Reliable performance Do not compromise on performance. The Latitude 3000

    E-Print Network [OSTI]

    Fiebig, Peter

    (Emerging Market), all 64 Bit Windows 7 Home Premium, Windows 7 Professional, Windows 7 Home Basic (Emerging, the Latitude 3000 Series offers a smart choice for an easy to manage environment. · Dell Data Protection l Market), 32 & 64 Bit Ubuntu 12.04 Long Term Support (LTS

  1. Safer Food with Irradiation

    E-Print Network [OSTI]

    Thompson, Britta; Vestal, Andy; Van Laanen, Peggy

    2003-01-21T23:59:59.000Z

    This publication answers questions about food irradiation and how it helps prevent foodborne illnesses. Included are explanations of how irradiation works and its benefits. Irradiation is a safe method of preserving food quality and ensuring its...

  2. Inspired Design The slim, light Latitude 6430u is simply beautiful from every

    E-Print Network [OSTI]

    Fiebig, Peter

    laptops ever. All systems are BFR/PVC- free2 , EPEAT registered3 , ENERGY STAR 5.2 qualified and offer of Latitude E-family laptops, the Latitude 6430u is amongst the most environmentally- responsible Latitude. Available with a 14.0" HD or 14.0" HD+ display4 and HDMI and VGA ports, it enables versatile usage

  3. WIND-DRIVEN NEAR INERTIAL OCEAN RESPONSE AND MIXING AT THE CRITICAL LATITUDE 

    E-Print Network [OSTI]

    Zhang, Xiaoqian

    2010-07-14T23:59:59.000Z

    ? latitude. Near 30? latitude, the maximum oceanic response to sea breeze moves offshore slowly because of the near-zero group speed of Poincare waves at this latitude. The lateral energy flux convergence plus the energy input from the wind is maximum near...

  4. Method for removing tilt control in adaptive optics systems

    DOE Patents [OSTI]

    Salmon, Joseph Thaddeus (Livermore, CA)

    1998-01-01T23:59:59.000Z

    A new adaptive optics system and method of operation, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation: G'=(I-X(X.sup.T X).sup.-1 X.sup.T)G(I-A)

  5. Method for removing tilt control in adaptive optics systems

    DOE Patents [OSTI]

    Salmon, J.T.

    1998-04-28T23:59:59.000Z

    A new adaptive optics system and method of operation are disclosed, whereby the method removes tilt control, and includes the steps of using a steering mirror to steer a wavefront in the desired direction, for aiming an impinging aberrated light beam in the direction of a deformable mirror. The deformable mirror has its surface deformed selectively by means of a plurality of actuators, and compensates, at least partially, for existing aberrations in the light beam. The light beam is split into an output beam and a sample beam, and the sample beam is sampled using a wavefront sensor. The sampled signals are converted into corresponding electrical signals for driving a controller, which, in turn, drives the deformable mirror in a feedback loop in response to the sampled signals, for compensating for aberrations in the wavefront. To this purpose, a displacement error (gradient) of the wavefront is measured, and adjusted by a modified gain matrix, which satisfies the following equation: G{prime} = (I{minus}X(X{sup T} X){sup {minus}1}X{sup T})G(I{minus}A). 3 figs.

  6. 'Tilting' the Universe with the Landscape Multiverse: The 'Dark' Flow

    E-Print Network [OSTI]

    L. Mersini-Houghton; R. Holman

    2008-10-30T23:59:59.000Z

    The theory for the selection of the initial state of the universe from the landscape multiverse predicts superhorizon inhomogeneities induced by nonlocal entanglement of our Hubble volume with modes and domains beyond the horizon. Here we show these naturally give rise to a bulk flow with correlation length of order horizon size. The modification to the gravitational potential has a characteristic scale $L_{1} \\simeq 10^{3} H^{-1}$, and it originates from the preinflationary remnants of the landscape. The 'tilt' in the potential induces power to the lowest CMB multipoles, with the dominant contribution being the dipole and next, the quadrupole. The induced multipoles $l \\le 2$ are aligned with an axis normal to their alignment plane being oriented along the preferred frame determined by the dipole. The preferred direction is displayed by the velocity field of the bulk flow relative to the expansion frame of the universe. The parameters are tightly constrained thus the derived modifications lead to robust predictions for testing our theory. The 'dark' flow was recently discovered by Kashlinsky et al. to be about $700 km/s$ which seems in good agreement with our predictions for the induced dipole of order $3 \\mu K$. Placed in this context, the discovery of the bulk flow by Kashlinsky et al. becomes even more interesting as it may provide a probe of the preinflationary physics and a window onto the landscape multiverse.

  7. Phonon thermal transport through tilt grain boundaries in strontium titanate

    SciTech Connect (OSTI)

    Zheng, Zexi; Chen, Xiang; Yang, Shengfeng; Xiong, Liming; Chen, Youping [Department of Mechanical and Aerospace Engineering, University of Florida, Gainesville, Florida 32611 (United States); Deng, Bowen; Chernatynskiy, Aleksandr [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)

    2014-08-21T23:59:59.000Z

    In this work, we perform nonequilibrium molecular dynamics simulations to study phonon scattering at two tilt grain boundaries (GBs) in SrTiO{sub 3}. Mode-wise energy transmission coefficients are obtained based on phonon wave-packet dynamics simulations. The Kapitza conductance is then quantified using a lattice dynamics approach. The obtained results of the Kapitza conductance of both GBs compare well with those obtained by the direct method, except for the temperature dependence. Contrary to common belief, the results of this work show that the optical modes in SrTiO{sub 3} contribute significantly to phonon thermal transport, accounting for over 50% of the Kapitza conductance. To understand the effect of the GB structural disorder on phonon transport, we compare the local phonon density of states of the atoms in the GB region with that in the single crystalline grain region. Our results show that the excess vibrational modes introduced by the structural disorder do not have a significant effect on phonon scattering at the GBs, but the absence of certain modes in the GB region appears to be responsible for phonon reflections at GBs. This work has also demonstrated phonon mode conversion and simultaneous generation of new modes. Some of the new modes have the same frequency as the initial wave packet, while some have the same wave vector but lower frequencies.

  8. Tilted CDM versus WDM in the Subgalactic Scuffle

    E-Print Network [OSTI]

    James S. Bullock

    2001-10-31T23:59:59.000Z

    Although the currently favored cold dark matter plus cosmological constant model (LCDM) has proven to be remarkably successful on large scales, on subgalactic scales it faces some potentially fatal difficulties; these include over-producing dwarf satellite galaxies and predicting excessive central densities in dark halos. Among the most natural cosmological solutions to these problems is to replace cold dark matter with a warm species (LWDM). The warm component acts to reduce the small-scale power, resulting in fewer galactic subhalos and lower halo central densities. An alternative model with a mild ``tilt'' in the inflationary power spectrum (TLCDM; n =0.9) similarly reduces the central densities of dark halos, although the substructure abundance remains relatively high. Here I argue that because dwarf galaxy formation should be suppressed in the presence of a strong ionizing background, favored LWDM models will generally under-predict the observed abundance of dwarf galaxies. The satellite count for TLCDM fairs much better, as long as the photoionization effect is taken into account. TLCDM provides a more successful alternative to LWDM on subgalactic scales with the added attraction that it relies on only a minor, natural adjustment to the standard framework of CDM.

  9. Tilt-up concrete panels : an investigation of flexural stresses and punching shear during lifting

    E-Print Network [OSTI]

    Bono, Matthew P. (Matthew Paul)

    2011-01-01T23:59:59.000Z

    Tilt-up construction is becoming more popular in the United States due to its ease of construction, reliability, and relatively low construction and maintenance costs. In its most typical form, a concrete panel is cast on ...

  10. Analysis of flexure pivot tilting pad gas bearings with different damper configurations 

    E-Print Network [OSTI]

    Rimpel, Aaron Michael

    2009-05-15T23:59:59.000Z

    Hydrodynamic flexure pivot tilting pad gas bearings (FPTPGBs) can enable successful operation of oil-free microturbomachinery. This work presents the experimental and analytical study of such bearings with different damper configurations. A test rig...

  11. A Novel Computational Model for Tilting Pad Journal Bearings with Soft Pivot Stiffnesses

    E-Print Network [OSTI]

    Tao, Yujiao 1988-

    2012-12-10T23:59:59.000Z

    A novel tilting pad journal bearing model including pivot flexibility as well as temporal fluid inertia effects on the thin film fluid flow aims to accurately predict the bearing forced performance. The predictive model also accounts for the thermal...

  12. Measurements of static loading characteristics of a Flexurepivot Tilt Pad Hydrodynamic Bearing

    E-Print Network [OSTI]

    Walton, Nicholas Van Edward

    1995-01-01T23:59:59.000Z

    An experimental investigation examining the static loading characteristics of a four-pad, KMC FLEXUREPIVOT Tilt Pad Hydrodynamic Bearing is presented. Tests are conducted on the TRACE Fluid Film Bearing Element Test Rig for journal speeds ranging...

  13. Design and characterization of a planar mechanism for passive tilt-compensation

    E-Print Network [OSTI]

    Lai, Justin Yi-Shen

    2007-01-01T23:59:59.000Z

    This work investigated the design and testing of a planar mechanism for passively compensating tilt between two flat surfaces brought into close proximity. The proposed design uses flexural components which eliminate ...

  14. K'-Theory of a Cohen-Macaulay Local Ring with n-Cluster Tilting Object

    E-Print Network [OSTI]

    Navkal, Viraj

    2013-01-01T23:59:59.000Z

    Categories and K-theory Definition 4.1. An exact category isLocalizations in K-Theory Definition 8.11. Let R be a ringdefinition of n-cluster tilting comes from invariant theory.

  15. Construction techniques and costs of tilt-up concrete farm structures

    E-Print Network [OSTI]

    Winsett, Ivan Lane

    1957-01-01T23:59:59.000Z

    ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 25 2S Ths warehouse with all Panels . 'honed and ths Pilaster Focal in Place Awaiting the Costing of ths Pilastars. . . . 29 14. Detail of Corner Pilaster~ Pilaster Fora, snd Footing Used in ths Concrete Tilt-Up w'arehouse . ~ . . ~ ~. . . . . 30... ~ ~ ~ ~ ~ ~ ~ 46 26. Detail of Zaproesd Corner Pilaster, Pilaster Rora, and Footing Used in the Concrete Tilt4p Anginal Shelter ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 48 27. The Antnal shelter heady for (hating the ConcNts Posts and PDa sts...

  16. MEASUREMENTS OF THE SUN'S HIGH-LATITUDE MERIDIONAL CIRCULATION

    SciTech Connect (OSTI)

    Rightmire-Upton, Lisa [Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Hathaway, David H. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); Kosak, Katie, E-mail: lar0009@uah.edu, E-mail: david.hathaway@nasa.gov, E-mail: mkosak2011@my.fit.edu [Florida Institute of Technology, Melbourne, FL 32901 (United States)

    2012-12-10T23:59:59.000Z

    The meridional circulation at high latitudes is crucial to the buildup and reversal of the Sun's polar magnetic fields. Here, we characterize the axisymmetric flows by applying a magnetic feature cross-correlation procedure to high-resolution magnetograms obtained by the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory. We focus on Carrington rotations 2096-2107 (2010 April to 2011 March)-the overlap interval between HMI and the Michelson Doppler Imager (MDI). HMI magnetograms averaged over 720 s are first mapped into heliographic coordinates. Strips from these maps are then cross-correlated to determine the distances in latitude and longitude that the magnetic element pattern has moved, thus providing meridional flow and differential rotation velocities for each rotation of the Sun. Flow velocities were averaged for the overlap interval and compared to results obtained from MDI data. This comparison indicates that these HMI images are rotated counterclockwise by 0.{sup 0}075 with respect to the Sun's rotation axis. The profiles indicate that HMI data can be used to reliably measure these axisymmetric flow velocities to at least within 5 Degree-Sign of the poles. Unlike the noisier MDI measurements, no evidence of a meridional flow counter-cell is seen in either hemisphere with the HMI measurements: poleward flow continues all the way to the poles. Slight north-south asymmetries are observed in the meridional flow. These asymmetries should contribute to the observed asymmetries in the polar fields and the timing of their reversals.

  17. A high galactic latitude survey of far ultraviolet excess objects

    SciTech Connect (OSTI)

    Bixler, J.V.

    1988-01-01T23:59:59.000Z

    Two closely related efforts in astrophysical instrumentation and observation are described with the objective of performing a high galactic latitude survey of faint objects in the far ultraviolet. The avenues of research possible with data obtained from space based ultraviolet surveys are discussed and a summary of past, present and planned instruments capable of such survey work presented. The Faust telescope, an eight degree field of view imaging instrument with peak sensitivity at 1700A, designed for survey work is described. An imaging, active readout detector and associated ground support equipment were designed, constructed, and calibrated to replace the original photographic detector. The present state of observational data relevant to determining the atmospheric parameters of subdwarf B and O stars, and their mid-Galactic plane density and scale height was reviewed. Theoretical explanations of their evolutionary status were proposed. The optical observations and spectral reductions performed on objects included in a catalog of far ultraviolet bright, high galactic latitude objects are described. These observations provide a sample of subdwarf O and B stars free of brightness and temperature selection effects. A model atmospheres analysis was performed on the subdwarf sample to determine the temperature, gravity and helium to hydrogen ratio of the individual objects. The results show a smooth distribution of objects on the gravity versus temperature diagram near the theoretical location of the extended horizontal branch.

  18. Blue-tilted Tensor Spectrum and Thermal History of the Universe

    E-Print Network [OSTI]

    Sachiko Kuroyanagi; Tomo Takahashi; Shuichiro Yokoyama

    2014-07-17T23:59:59.000Z

    We investigate constraints on the spectral index of primordial gravitational waves (GWs), paying particular attention to a blue-tilted spectrum. Such constraints can be used to test a certain class of models of the early Universe. We investigate observational bounds from LIGO+Virgo, pulsar timing and big bang nucleosynthesis, taking into account the suppression of the amplitude at high frequencies due to reheating after inflation and also late-time entropy production. Constraints on the spectral index are presented by changing values of parameters such as reheating temperatures and the amount of entropy produced at late time. We also consider constraints under the general modeling approach which can approximately describe various scenarios of the early Universe. We show that the constraints on the blue spectral tilt strongly depend on the underlying assumption and, in some cases, a highly blue-tilted spectrum can still be allowed.

  19. No evidence for the blue-tilted power spectrum of relic gravitational waves

    E-Print Network [OSTI]

    Huang, Qing-Guo

    2015-01-01T23:59:59.000Z

    In this paper, we constrain the tilt of the power spectrum of relic gravitational waves by combining the data from BICEP2/Keck array and Planck (BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). From the data of BKP B-modes, the constraint on the tensor tilt is $n_t=0.66^{+1.83}_{-1.44}$ at the $68%$ confidence level. By further adding the LIGO upper limit on the energy density of gravitational waves, the constraint becomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We conclude that there is no evidence for a blue-tilted power spectrum of relic gravitational waves and either sign of the index of tensor power spectrum is compatible with the data.

  20. No evidence for the blue-tilted power spectrum of relic gravitational waves

    E-Print Network [OSTI]

    Qing-Guo Huang; Sai Wang

    2015-02-09T23:59:59.000Z

    In this paper, we constrain the tilt of the power spectrum of relic gravitational waves by combining the data from BICEP2/Keck array and Planck (BKP) and the Laser Interferometer Gravitational-Waves Observatory (LIGO). From the data of BKP B-modes, the constraint on the tensor tilt is $n_t=0.66^{+1.83}_{-1.44}$ at the $68%$ confidence level. By further adding the LIGO upper limit on the energy density of gravitational waves, the constraint becomes $n_t=-0.76^{+1.37}_{-0.52}$ at the $68%$ confidence level. We conclude that there is no evidence for a blue-tilted power spectrum of relic gravitational waves and either sign of the index of tensor power spectrum is compatible with the data.

  1. Design and initial characterization of a compact, ultra high vacuum compatible, low frequency, tilt accelerometer

    SciTech Connect (OSTI)

    O’Toole, A., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Peña Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Rodionov, A. V.; Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States); Shaner, M.; Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street Pasadena, California 91105 (United States); Sobacchi, E. [Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa (Italy); Dergachev, V.; DeSalvo, R., E-mail: amandajotoole@gmail.com, E-mail: riccardo.desalvo@gmail.com [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientfica 1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia)

    2014-07-15T23:59:59.000Z

    A compact tilt accelerometer with high sensitivity at low frequency was designed to provide low frequency corrections for the feedback signal of the Advanced Laser Interferometer Gravitational Wave Observatory active seismic attenuation system. It has been developed using a Tungsten Carbide ceramic knife-edge hinge designed to avoid the mechanical 1/f noise believed to be intrinsic in polycrystalline metallic flexures. Design and construction details are presented; prototype data acquisition and control limitations are discussed. The instrument's characterization reported here shows that the hinge is compatible with being metal-hysteresis-free, and therefore also free of the 1/f noise generated by the dislocation Self-Organized Criticality in the metal. A tiltmeter of this kind will be effective to separate the ground tilt component from the signal of horizontal low frequency seismometers, and to correct the ill effects of microseismic tilt in advanced seismic attenuation systems.

  2. Numerical relativity simulations of thick accretion disks around tilted Kerr black holes

    E-Print Network [OSTI]

    Vassilios Mewes; José A. Font; Filippo Galeazzi; Pedro J. Montero; Nikolaos Stergioulas

    2015-06-12T23:59:59.000Z

    In this work we present 3D numerical relativity simulations of thick accretion disks around {\\it tilted} Kerr black holes. We investigate the evolution of three different initial disk models with a range of initial black hole spin magnitudes and tilt angles. For all the disk-to-black hole mass ratios considered ($0.044-0.16$) we observe significant black hole precession and nutation during the evolution. This indicates that for such mass ratios, neglecting the self-gravity of the disks by evolving them in a fixed background black hole spacetime is not justified. We find that the two more massive models are unstable against the Papaloizou-Pringle (PP) instability and that those PP-unstable models remain unstable for all initial spins and tilt angles considered, showing that the development of the instability is a very robust feature of such PP-unstable disks. The tilt between the black hole spin and the disk is strongly modulated during the growth of the PP instability, causing a partial global realignment of black hole spin and disk angular momentum in the most massive model with constant specific angular momentum $l$. For the model with non-constant $l$-profile we observe a long-lived $m=1$ non-axisymmetric structure which shows strong oscillations of the tilt angle in the inner regions of the disk. We attribute this effect to the development of Kozai-Lidov oscillations. Our simulations also confirm earlier findings that the development of the PP instability causes the long-term emission of large amplitude gravitational waves, predominantly for the $l=m=2$ multipole mode. The imprint of the BH precession on the gravitational waves from tilted BH-torus systems remains an interesting open issue that would require significantly longer simulations than those presented in this work.

  3. The Structure of the Homunculus: I. Shape and Latitude Dependence from H2 and [Fe II] Velocity Maps of Eta Carinae

    E-Print Network [OSTI]

    Nathan Smith

    2006-02-21T23:59:59.000Z

    High resolution long-slit spectra obtained with the Phoenix spectrograph on Gemini South provide our most accurate probe of the three dimensional structure of the Homunculus around eta Car. The new near-infrared spectra dramatically confirm the double-shell structure inferred previously from thermal dust emission, resolving the nebula into a very thin outer shell seen in H2 21218, and a warmer, thicker inner layer seen in [Fe II] 16435. The thin H2 skin hints that the most important mass loss during the 19th century eruption had a very short duration of less than 5 yr. H2 emission traces the majority of the mass in the nebula, and has an average density of order 10^6.5 cm-3. This emission, in turn, yields our first definitive picture of the exact shape of the nebula, plus a distance of 2350pm50 pc and an inclination angle of 41deg (the polar axis is tilted 49deg from the plane of the sky). The distribution of the H2 emission provides the first measure of the latitude dependence of the speed, mass loss, and kinetic energy associated with eta Car's 19th century explosion. Almost 75 percent of the total mass and more than 90 percent of the kinetic energy in the ejecta were released at high latitudes. This rules out a model for the bipolar shape wherein an otherwise spherical explosion was pinched at the waist by a circumstellar torus. Also, the ejecta could not have been deflected toward polar trajectories by a companion star, since the kinetic energy of the polar ejecta is greater than the binding energy of the putative binary system. Instead, most of the mass appears to have been directed poleward by the explosion itself. [abridged

  4. Volume 177, number 2 CHEMICAL PHYSICS LETTERS 15 February 1991 Cu titration of tilted CO on a MO( 110) surface

    E-Print Network [OSTI]

    Goodman, Wayne

    to the surface normal. Upon subsequent deposition of = 0.9 ML Cu at 95 Kfollowed by heating, infrared, in a weakening of the C-O bond [ l-41. The tilted CO can either dissociate into atomic C and 0 upon heating to z) surface. In this Letter, we present the results of studies on tilted CO on MO( 110) using infrared

  5. PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan1

    E-Print Network [OSTI]

    PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan1 , Ilya Tsvankin2 , Mike Batzle3 , Kasper van Wijk4 , and Matthew Haney5 ABSTRACT Mode-converted PS-waves can- and PS- waves can be inverted for the parameters of a horizontal TI layer with a tilted symmetry axis

  6. Tilted Micro Air Jet for Flow Control Julien Malapert*, Rda Yahiaoui, Rabah Zeggari and Jean-Franois Manceau

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Tilted Micro Air Jet for Flow Control Julien Malapert*, Réda Yahiaoui°, Rabah Zeggari and Jean: In this paper, we present an interesting method to microfabricate a tilted micro air jet generator. We used a double side etching. For aircraft and cars, micro air jets will take an important place for fluid control

  7. First Flight Tests for a Quadrotor UAV with Tilting Propellers Markus Ryll, Heinrich H. Bulthoff, and Paolo Robuffo Giordano

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    ]. For these latter platforms, only the Cartesian position and yaw angle of their body frame w.r.t. an inertial frame directions. As quadrotor UAVs are being more and more exploited as autonomous flying service robots [3], [4: ducted-fan designs [5], tilt-wing mechanisms [6], [7], or tilt-rotor actuations [8], [9]. Along similar

  8. Properties of localized, high latitude, dayside aurora H. U. Frey,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    Properties of localized, high latitude, dayside aurora H. U. Frey,1 T. J. Immel,1 G. Lu,2 J different type of high latitude aurora, which does not show any signature of precipitating protons. It also causes the aurora. We interpret this aurora as the optical signature of electron precipitation

  9. Very low latitude (L = 1.08) whistlers Rajesh Singh,1

    E-Print Network [OSTI]

    currents of whistler-producing lightning, which demonstrate a cutoff at 30 kA. Citation: Singh, R., M. B is much larger in a duct propagation than in non-ducted. At low latitudes (geomagnetic latitude the transmission cone. On the other hand, earlier studies utilized direction finding measurements to investigate

  10. Seasonal persistence of northern low-and middle-latitude anomalies of ozone and

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Seasonal persistence of northern low- and middle-latitude anomalies of ozone and other trace gases #12;Seasonal persistence of northern low- and middle-latitude anomalies of ozone and other trace gases 10 July 2008; accepted 23 July 2008; published 11 November 2008. [1] Analysis of observed ozone

  11. High-latitude dayside energetic precipitation and IMF BZ rotations N. stgaard,1

    E-Print Network [OSTI]

    California at Berkeley, University of

    . Owing to the high latitudes it is unlikely that these electrons were energized on the nightside by the solar wind. The precipitation appears at $77­79° magnetic latitude and coincides with a northward Ionosphere: Auroral ionosphere (2704); 2784 Magnetospheric Physics: Solar wind/magnetosphere interactions

  12. Beta diversity and latitude in North American mammals: testing the hypothesis of covariation

    E-Print Network [OSTI]

    Nacional Autónoma de México, Universidad

    Beta diversity and latitude in North American mammals: testing the hypothesis of covariation Pilar Rodri´guez and He´ctor T. Arita Rodri´guez, P. and Arita, H. T. 2004. Beta diversity and latitude of the pattern remain insufficiently explored, including the effect of scales and the role of beta diversity

  13. Extended scaling factors for in situ cosmogenic nuclides: New measurements at low latitude

    E-Print Network [OSTI]

    Zreda, Marek

    Extended scaling factors for in situ cosmogenic nuclides: New measurements at low latitude Darin by the intensity of energetic cosmic-ray nucleons, which changes rapidly with elevation. An incomplete knowledge, and that there has been an incomplete mapping of nucleon fluxes at high RC (low geomagnetic latitude). We report new

  14. METR 4133, Atmospheric Dynamics III: Mid-Latitude Synoptic-Scale Dynamics

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    METR 4133, Atmospheric Dynamics III: Mid-Latitude Synoptic- Scale Dynamics Fall 2012 Instructor Dr and Thurs, 11:30 am ­ 12:45 pm Required Texts Bluestein, H., 1992: Synoptic-Dynamic Meteorology in Mid-Latitudes, Volume I: Principles of Kinematics and Dynamics. Oxford Univ. Press, 431pp. Bluestein, H., 1993: Synoptic-Dynamic

  15. Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting

    E-Print Network [OSTI]

    Mueser, Martin

    Friction in (im-)miscible polymer brush systems and the role of transverse polymer-tilting Sissi de preferred solvent, leading to low friction and low wear rates. Here, we demonstrate, using molecular systems also show smaller friction than miscible systems, although the friction reduction is less than

  16. TILTED LAYER-BASED MODELING FOR ENHANCED LIGHT-FIELD PROCESSING AND IMAGE BASED RENDERING

    E-Print Network [OSTI]

    Dragotti, Pier Luigi

    TILTED LAYER-BASED MODELING FOR ENHANCED LIGHT-FIELD PROCESSING AND IMAGE BASED RENDERING James, UK {j.pearson09, marcovs, mike.brookes, p.dragotti}@imperial.ac.uk ABSTRACT Image based rendering- torealistic results. However for successful rendering, geometric pri- ors about the structure of the scene

  17. Atomistic simulations of structures and mechanical properties of polycrystalline diamond: Symmetrical S001< tilt grain boundaries

    E-Print Network [OSTI]

    Brenner, Donald W.

    Atomistic simulations of structures and mechanical properties of polycrystalline diamond for diamond to deposit as a polycrystalline film with a high density of grain boundaries and related defects structures and energies of symmetrical 001 tilt grain boundaries GB's in diamond have been calculated over

  18. Tilt Aftereffects in a Self-Organizing Model of the Primary Visual Cortex

    E-Print Network [OSTI]

    2000-01-01T23:59:59.000Z

    RF-LISSOM, a self-organizing model of laterally connected orientation maps in the primary visual cortex, was used to study the psychological phenomenon known as the tilt aftereffect. The same self-organizing processes that are responsible for the long-term development of the map are shown to result in tilt aftereffects over short time scales in the adult. The model permits simultaneous observation of large numbers of neurons and connections, making it possible to relate high-level phenomena to low-level events, which is difficult to do experimentally. The results give detailed computational support for the long-standing conjecture that the direct tilt aftereffect arises from adaptive lateral interactions between feature detectors. They also make a new prediction that the indirect effect results from the normalization of synaptic efficacies during this process. The model thus provides a unified computational explanation of self-organization and both the direct and indirect tilt aftereffect in the primary visual cortex.

  19. Tilting mirror strips in a linear Fresnel reector Gang Xiao (University of Nice, France)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Tilting mirror strips in a linear Fresnel reector Gang Xiao (University of Nice, France) February 29, 2012 Abstract When a linear Fresnel reector solar concentrator is installed in a site with high of the linear Fresnel reector. Technical restrictions and diculties of this method are also discussed

  20. Evidence of a tilted columnar structure for mesomorphic phases of benzene-hexa-n-alkanoates

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1285 Evidence of a tilted columnar structure for mesomorphic phases of benzene-hexa-n-alkanoates F. 2014 Optical observations on the mesomorphs of benzene-hexa-n-alkanoates, and their admixtures with benzene, show that the planes of these discotic molecules are not perpendicular to the columns in which

  1. Comminuting irradiated ferritic steel

    DOE Patents [OSTI]

    Bauer, Roger E. (Kennewick, WA); Straalsund, Jerry L. (Kennewick, WA); Chin, Bryan A. (Auburn, AL)

    1985-01-01T23:59:59.000Z

    Disclosed is a method of comminuting irradiated ferritic steel by placing the steel in a solution of a compound selected from the group consisting of sulfamic acid, bisulfate, and mixtures thereof. The ferritic steel is used as cladding on nuclear fuel rods or other irradiated components.

  2. Irradiation Creep in Graphite

    SciTech Connect (OSTI)

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13T23:59:59.000Z

    An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

  3. Diffuse Galactic Light in the Field of the Translucent High Galactic Latitude Cloud MBM32

    E-Print Network [OSTI]

    Ienaka, N; Matsuoka, Y; Sameshima, H; Oyabu, S; Tsujimoto, T; Peterson, B A

    2013-01-01T23:59:59.000Z

    We have conducted B, g, V, and R-band imaging in a 45x40 arcmin^2 field containing part of the high Galactic latitude translucent cloud MBM32, and correlated the intensity of diffuse optical light S_\

  4. Alfven field line resonances at low latitudes (L = 1.5)

    SciTech Connect (OSTI)

    Green, A.W.; Worthington, E.W. [Geological Survey, Denver, CO (United States); Baransky, L.N.; Fedorov, E.N.; Kurneva, N.A.; Pilipenko, V.A.; Shvetzov, D.N. [Institute of the Physics of the Earth, Moscow (Russian Federation); Bektemirov, A.A.; Philipov, G.V. [Institute of Seismology of Kyrgyzian Academy of Science, Bishkek (Kyrgyzstan)

    1993-09-01T23:59:59.000Z

    Here the authors present preliminary analysis of measurements of the spatial structure of ULF waves in the low latitude ionosphere. They used a gradient analysis method to demonstrate that Pc3 Alfven field line resonances do exist at L=1.5. The authors recorded resonance frequencies, resonance widths, and radial gradients of Alfven frequencies. The widths are found to increase with decreasing latitude, which is attributed to increased ionospheric damping.

  5. An experimental investigation of a tilt rotor aircraft wake in ground effect

    E-Print Network [OSTI]

    Frey, Michael Louis

    1982-01-01T23:59:59.000Z

    were taken at several disk loadings and various model to ground plane distances. The data collected was used to evaluate the horizontal wake component's effect on people by re- lating the experimental velocity profiles to an equivalent uniform... Flow Measurement Equipment. Wake Velocity Versus Distance from Tilt Rotor Wake Velocity Versus Disk Loading Tuft Flow Visualization ? H=3D, 3, 000 RPM Tuft Flow Visualization ? H=2D, 9, 000 RPM Flow Direction Measurement Results ? H=1D 14 20 22...

  6. Measurement of rotordynamic coefficients for a high-speed flexure pivot tilting-pad bearing(load between pad) configuration

    E-Print Network [OSTI]

    Al-Ghasem, Adnan Mahmoud

    2005-08-29T23:59:59.000Z

    This thesis presents the dynamic and static forced performance of a flexure-pivot tilting-pad bearing load between pad (LBP) configuration for different rotor speeds and bearing unit loadings. The bearing has the following design parameters: 4 pads...

  7. Measured and Predicted Rotor-Pad Transfer Functions for a Rocker-Pivot Tilting-Pad Journal Bearing

    E-Print Network [OSTI]

    Wilkes, Jason Christopher

    2012-02-14T23:59:59.000Z

    Many researchers have compared predicted stiffness and damping coefficients for tilting-pad journal bearings (TPJBs) to measurements. Most have found that direct damping is consistently overpredicted. The thrust of this research is to explain...

  8. Effects of head-up tilt on mean arterial pressure, heart rate, and regional cardiac output distribution in aging rats 

    E-Print Network [OSTI]

    Ramsey, Michael Wiechmann

    2006-04-12T23:59:59.000Z

    Many senescent individuals demonstrate an inability to regulate mean arterial pressure (MAP) in response to standing or head-up tilt; however, whether this aging effect is the result of depressed cardiac function or an ...

  9. Red and blue tilted tensor spectrum from Gibbons-Hawking temperature

    E-Print Network [OSTI]

    Subhendra Mohanty; Akhilesh Nautiyal

    2015-01-09T23:59:59.000Z

    The scale invariant scalar and tensor perturbations, which are predicted from inflation, are eigenmodes in the conformal coordinates. The 'out' observer in the de Sitter space observes a thermal spectrum with a Gibbons-Hawking temperature $H/2\\pi$ of these 'Bunch-Davies' particles. The tensor power spectrum observed in experiments can have an imprint of the Gibbons-Hawking thermal distribution due to the mode mixing between 'in' state conformal coordinates and the coordinate frame of the observer. We find that the the Bunch-Davies modes appear as thermal modes to the asymptotic Minkowski observer in the future and the power spectrum of the gravitational waves is blue-tilted with a spectral index $n_T \\sim 1$ even in the standard slow-roll inflation. On the other hand if the coordinate frame of the observer is taken to be static coordinates, the tensor spectrum is red-tilted with $n_T\\sim -1$. A likelihood analysis shows and find the best fit values of the slow-roll parameters for both cases. We find that the blue-tilted tensor gives a better fit and reconciles the PLANCK upper bound on the tensor-to-scalar ratio, $r <0.11$ with BICEP2 measurement of $r=0.2$. This supports the idea of particle production due to the mode mixing between the initial Bunch-Davies vacuum modes and the asymptotic Minkowski vacuum of the post-inflation universe.

  10. Hybrid monitor for both beam position and tilt of pulsed high-current beams

    SciTech Connect (OSTI)

    Pang, J., E-mail: jpang-caep@foxmail.com; He, X.; Ma, C.; Zhao, L.; Li, Q.; Dai, Z. [Key Laboratory of Pulsed Power, Institute of Fluid Physics, CAEP, P.O. Box 919-106, Mianyang 621900 (China)

    2014-09-15T23:59:59.000Z

    A Hybrid beam monitor, integrated with both azimuthal and axial B-dot probes, was designed for simultaneous measurement of both beam position and beam angle for pulsed high-current beams at the same location in beam pipe. The output signals of axial B-dot probes were found to be mixed with signals caused by transverse position deviation. In order to eliminate the unwanted signals, an elimination method was developed and its feasibility tested on a 50-? coaxial line test stand. By this method, a waveform, shape-like to that of input current and proportional to the tilt angle, was simulated and processed by following integration step to achieve the tilt angle. The tests showed that the measurement error of displacement and tilt angle less than 0.3 mm and 1.5 mrad, respectively. The latter error could be reduced with improved probes by reducing the inductance of the axial B-dot probe, but the improvement reached a limit due to some unknown systemic mechanism.

  11. An Analysis of Source Tilting and Sub-cell Opacity Sampling for IMC

    SciTech Connect (OSTI)

    Wollaeger, Ryan T. [Los Alamos National Laboratory; Urbatsch, Todd J. [Los Alamos National Laboratory; Wollaber, Allan B. [Los Alamos National Laboratory; Densmore, Jeffery D. [Los Alamos National Laboratory

    2012-08-02T23:59:59.000Z

    Implicit Monte Carlo (IMC) is a stochastic method for solving the radiative transfer equations for multiphysics application with the material in local thermodynamic equilibrium. The IMC method employs a fictitious scattering term that is computed from an implicit discretization of the material temperature equation. Unfortunately, the original histogram representation of the temperature and opacity with respect to the spatial domain leads to nonphysically fast propagation of radiation waves through optically thick material. In the past, heuristic source tilting schemes have been used to mitigate the numerical teleportation error of the radiation particles in IMC that cause this overly rapid radiation wave propagation. While improving the material temperature profile throughout the time duration, these tilting schemes alone do not generally alleviate the teleportation error to suitable levels. Another means of potentially reducing teleportation error in IMC is implementing continuous sub-cell opacities based on sub-cell temperature profiles. We present here an analysis of source tilting and continuous sub-cell opacity sampling applied to various discretizations of the temperature equation. Through this analysis, we demonstrate that applying both heuristics does not necessarily yield more accurate results if the discretization of the material equation is inconsistent with the Monte Carlo sub-cell transport.

  12. Ferroelectric and octahedral tilt twin disorder and the lead-free piezoelectric, sodium potassium niobate system

    SciTech Connect (OSTI)

    Schiemer, Jason [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia); Withers, Ray L., E-mail: withers@rsc.anu.edu.au [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia); Liu, Yun; Yi, Zhiguo [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)] [Research School of Chemistry, The Australian National University, Canberra, ACT 0200 (Australia)

    2012-11-15T23:59:59.000Z

    Using electron diffraction, trends in the local structural behaviour of the K{sub x}Na{sub 1-x}NbO{sub 3} (KNN x) 'solid solution' system are investigated and interpreted using an order/disorder based theoretical framework. At room temperature, electron diffraction shows a single plane of transverse polarised, diffuse intensity perpendicular to [0 1 0]{sub p} Low-Asterisk (p for parent sub-structure) across the entire phase diagram, indicative of ferroelectric disorder along the [0 1 0]{sub p} direction co-existing with long range ferroelectric order along the orthogonal [1 0 0]{sub p} and [0 0 1]{sub p} directions. An additional characteristic pattern of diffuse scattering is also observed, involving rods of diffuse intensity running along the [1 0 0]{sub p}* and [0 0 1]{sub p}* directions of the perovskite sub-structure and indicative of octahedral tilt disorder about the [1 0 0]{sub p} and [0 0 1]{sub p} axes co-existing with long range ordered octahedral tilting around the [0 1 0]{sub p} direction. A possible crystal chemical explanation for the existence of this latter octahedral tilt disorder is explored through bond valence sum calculations. The possible influence of both types of disorder on the previously refined, room temperature space group/s and average crystal structure/s is examined. - Graphical abstract: [-3,0.-1]p zone axis EDP of K{sub 0.46}Na{sub 0.54}NbO{sub 3} indexed according to both the relevant Pcm21 space groups (no subscripts) and the parent perovskite subcell (denoted by a subscript p). Highlights: Black-Right-Pointing-Pointer Characterises ferroelectric and octahedral tilt disorder in the KNN solid solution. Black-Right-Pointing-Pointer Discusses the possible driving forces for this disorder. Black-Right-Pointing-Pointer Discusses the implications of this disorder for physical properties. Black-Right-Pointing-Pointer Discusses the effects of this disorder on powder diffraction data.

  13. Dual-frequency terahertz emission from splitting filaments induced by lens tilting in air

    SciTech Connect (OSTI)

    Zhang, Zhelin; Chen, Yanping, E-mail: yanping.chen@sjtu.edu.cn; Yang, Liu; Yuan, Xiaohui; Liu, Feng; Chen, Min; Xu, Jianqiu; Zhang, Jie [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Sheng, Zhengming [Key Laboratory for Laser Plasmas (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2014-09-08T23:59:59.000Z

    Dual-frequency terahertz radiation from air-plasma filaments produced with two-color lasers in air has been demonstrated experimentally. When a focusing lens is tilted for a few degrees, it is shown that the laser filament evolves from a single one to two sub-filaments. Two independent terahertz sources emitted from the sub-filaments with different frequencies and polarizations are identified, where the frequency of terahertz waves from the trailing sub-filament is higher than that from the leading sub-filament.

  14. Accurate measurement of relative tilt and azimuth angles in electron tomography: A comparison of fiducial marker method with electron diffraction

    SciTech Connect (OSTI)

    Hayashida, Misa [National Metrology Institute of Japan, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1, Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Malac, Marek; Egerton, Ray F. [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada); Department of Physics, University of Alberta, Edmonton T6H 2E1 (Canada); Bergen, Michael; Li, Peng [National Institute for Nanotechnology, 11421 Saskatchewan Drive, Edmonton T6G 2M9 (Canada)

    2014-08-15T23:59:59.000Z

    Electron tomography is a method whereby a three-dimensional reconstruction of a nanoscale object is obtained from a series of projected images measured in a transmission electron microscope. We developed an electron-diffraction method to measure the tilt and azimuth angles, with Kikuchi lines used to align a series of diffraction patterns obtained with each image of the tilt series. Since it is based on electron diffraction, the method is not affected by sample drift and is not sensitive to sample thickness, whereas tilt angle measurement and alignment using fiducial-marker methods are affected by both sample drift and thickness. The accuracy of the diffraction method benefits reconstructions with a large number of voxels, where both high spatial resolution and a large field of view are desired. The diffraction method allows both the tilt and azimuth angle to be measured, while fiducial marker methods typically treat the tilt and azimuth angle as an unknown parameter. The diffraction method can be also used to estimate the accuracy of the fiducial marker method, and the sample-stage accuracy. A nano-dot fiducial marker measurement differs from a diffraction measurement by no more than ±1°.

  15. Irradiation Stability of Carbon Nanotubes 

    E-Print Network [OSTI]

    Aitkaliyeva, Assel

    2010-01-14T23:59:59.000Z

    Ion irradiation of carbon nanotubes is a tool that can be used to achieve modification of the structure. Irradiation stability of carbon nanotubes was studied by ion and electron bombardment of the samples. Different ion ...

  16. Early structure formation from primordial density fluctuations with a blue-tilted power spectrum

    E-Print Network [OSTI]

    Hirano, Shingo; Yoshida, Naoki; Spergel, David; Yorke, Harold W

    2015-01-01T23:59:59.000Z

    While observations of large-scale structure and the cosmic microwave background (CMB) provide strong constraints on the amplitude of the primordial power spectrum (PPS) on scales larger than 10 Mpc, the amplitude of the power spectrum on sub-galactic length scales is much more poorly constrained. We study early structure formation in a cosmological model with a blue-tilted PPS. We assume that the standard scale-invariant PPS is modified at small length scales as $P(k) \\sim k^{m_{\\rm s}}$ with $m_{\\rm s} > 1$. We run a series of cosmological hydrodynamic simulations to examine the dependence of the formation epoch and the characteristic mass of primordial stars on the tilt of the PPS. In models with $m_{\\rm s} > 1$, star-forming gas clouds are formed at $z > 100$, when formation of hydrogen molecules is inefficient because the intense CMB radiation destroys chemical intermediates. Without efficient coolant, the gas clouds gravitationally contract while keeping a high temperature. The protostars formed in such ...

  17. The Tilt of the Fundamental Plane: Three-quarters Structural Nonhomology, One-quarter Stellar Population

    E-Print Network [OSTI]

    I. Trujillo; A. Burkert; Eric. F. Bell

    2004-01-09T23:59:59.000Z

    The variation of the mass-to-light ratios M/L of early type galaxies as function of their luminosities L is investigated. It is shown that the tilt beta=0.27 (in the B--band) of the fundamental plane relation M/L ~ L^{beta} can be understood as a combination of two effects: about one-quarter (i.e. dbeta =0.07) is a result of systematic variations of the stellar population properties with increasing luminosity. The remaining three-quarters (i.e. dbeta =0.2) can be completely attributed to nonhomology effects that lead to a systematic change of the surface brightness profiles with increasing luminosity. Consequently, the observed tilt in the K-band (beta=0.17) where stellar population effects are negligible, is explained by nonhomology effects alone. After correcting for nonhomology, the mean value of the mass-to-light ratio of elliptical galaxies (M/L_B) is 7.1+-2.8 (1 sigma scatter).

  18. Mechanical and charge transport properties of alkanethiol self-assembled monolayers on Au (111) surface: The Role of Molecular Tilt

    SciTech Connect (OSTI)

    Mulleregan, Alice; Qi, Yabing; Ratera, Imma; Park, Jeong Y.; Ashby, Paul D.; Quek, Su Ying; Neaton, J. B.; Salmeron, Miquel

    2007-11-12T23:59:59.000Z

    The relationship between charge transport and mechanical properties of alkanethiol self-assembled monolayers (SAM) on Au(111) films has been investigated using an atomic force microscope with a conductive tip. Molecular tilts induced by the pressure applied by the tip cause stepwise increases in film conductivity. A decay constant {beta} = 0.57 {+-} 0.03 {angstrom}{sup -1} was found for the current passing through the film as a function of tip-substrate separation due to this molecular tilt. This is significantly smaller than the value of {approx} 1 {angstrom}{sup -1} found when the separation is changed by changing the length of the alkanethiol molecules. Calculations indicate that for isolated dithiol molecules S-bonded to hollow sites, the junction conductance does not vary significantly as a function of molecular tilt. The impact of S-Au bonding on SAM conductance is discussed.

  19. LOCATION AND MAGNETOSPHERIC MAPPING OF SATURN'S MID-LATITUDE INFRARED AURORAL OVAL

    SciTech Connect (OSTI)

    Stallard, Tom; Melin, Henrik; Cowley, Stanley W. H. [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom); Miller, Steve [Department of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom); Lystrup, Makenzie B., E-mail: tss@ion.le.ac.u [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, CO 80303-7814 (United States)

    2010-10-10T23:59:59.000Z

    Previous observations of Saturn's infrared aurorae have shown that a mid-latitude aurora exists significantly equatorward of the main auroral oval. Here, we present new results using data from four separate observing runs in 1998, 2003, 2008, and 2010. When combined, these provide a view of the mid-latitude aurora under a considerable range of viewing conditions, allowing the first calculation of the latitudinal position of this aurora to be made. This has shown that the mid-latitude aurora is located at the magnetic footprint of the region within the magnetosphere where the initial breakdown in corotation occurs, between 3 R {sub S} and the orbit of Enceladus ({approx}3.95 R {sub S}). We also confirm that this aurora is a continuous stable feature over a period of more than a decade and that an oval morphology is likely. When combined, these results indicate that the mid-latitude auroral oval is formed by currents driven by the breakdown process within the magnetosphere, in turn caused by mass loading from the torus of Enceladus, analogous with the volcanic moon Io's dominant role in the formation of Jupiter's main auroral oval.

  20. Eastward propagation of transient field-aligned currents and Pi 2 pulsations at auroral latitudes

    SciTech Connect (OSTI)

    Webster, D.J.; Samson, J.C.; Rostoker, G. (Univ. of Alberta, Edmonton (Canada))

    1989-04-01T23:59:59.000Z

    Transient field-aligned currents associated with the substorm expansive phase produce the damped, quasisinusoidal, geomagnetic pulsations called Pi 2's. Mid-latitude and auroral latitude measurements of the fields of these pulsations have indicated that they are produced, for the most part, by westward propagating field-aligned currents at auroral latitudes, although some studies have shown hints of eastward propagation, particularly far to the east of the longitude of the onset of the expansive phase. This study uses data from the University of Alberta magnetometer array to identify the characteristics of the eastward propagating mode at high latitudes by measuring polarizations and apparent group and phase velocities in regions far to the east of the expansive phase. The results show that eastward propagating Pi 2's have very high phase velocities (typically 40 km/s) which are comparable with those of the westward propagating mode. The polarizations and field configurations are compatible with a field-aligned and ionospheric current model which is very similar to that for the westward propagating component. These current models suggest that Pi 2's may be caused by shear Alfven waves produced by an azimuthally expanding, fast mode wave. The shear Alfven waves are reflected from the auroral ionosphere to produce the latitudinally localized field-aligned and ionospheric currents in the eastward (and westward) propagating modes.

  1. High latitude geomagnetically induced current events observed on very low frequency radio wave receiver systems

    E-Print Network [OSTI]

    Otago, University of

    High latitude geomagnetically induced current events observed on very low frequency radio wave induced current (GIC) in the Scottish power system in southern Scotland, during a storm event, and exhibit significantly different amplitude characteristics. Finally, we compared in detail the geomagnetic

  2. Friction in Mid-latitude Bob Plant, Stephen Belcher, Bob Beare, Andy Brown

    E-Print Network [OSTI]

    Plant, Robert

    Friction in Mid-latitude Cyclones Ian Boutle Bob Plant, Stephen Belcher, Bob Beare, Andy Brown #12;Motivation · Many studies have shown the significance of friction in formation and dissipation of cyclones Dt = + × . F . Diabatic Term: · Surface heat fluxes · Latent heat fluxes Frictional Term

  3. On the paucity of Fast Radio Bursts at low Galactic latitudes

    E-Print Network [OSTI]

    Macquart, Jean-Pierre

    2015-01-01T23:59:59.000Z

    We examine the effect of Galactic diffractive interstellar scintillation as a means of explaining the reported deficit of Fast Radio Burst (FRB) detections at low Galactic latitude. We model the unknown underlying FRB flux density distribution as a power law with a rate scaling as $S_\

  4. LOOKING FOR VARIATIONS WITH LATITUDE OF THE BASE OF THE SOLAR CONVECTION ZONE

    E-Print Network [OSTI]

    Monteiro, Mário João

    819 LOOKING FOR VARIATIONS WITH LATITUDE OF THE BASE OF THE SOLAR CONVECTION ZONE M Astronomy Unit, School of Mathematical Sciences, Queen Mary & Westfield College, Mile End Road, London El 4 successfully in determining the basic characteristics of the base of the solar convec- tive region (e

  5. Role of latitude of source region in Solar Energetic Particle events

    E-Print Network [OSTI]

    Sanahuja, Blai

    PR1 2HE, UK Department of Physics, University of Helsinki, 00014 Helsinki, Finland Abstract. Solar up to near- relativistic energies. Some of these particles can escape the solar atmosphere and travelRole of latitude of source region in Solar Energetic Particle events S. Dalla and N. Agueda1

  6. THE ROTATION PROFILE OF SOLAR MAGNETIC FIELDS BETWEEN {+-}60 Degree-Sign LATITUDES

    SciTech Connect (OSTI)

    Shi, X. J.; Xie, J. L., E-mail: shixiangjun@ynao.ac.cn [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China)

    2013-08-10T23:59:59.000Z

    Through a cross-correlation analysis of the Carrington synoptic maps of solar photospheric magnetic fields from Carrington Rotation Nos. 1625 to 2129 (from 1975 February to 2012 October), the sidereal rotation rates of solar magnetic fields between {+-}60 Degree-Sign latitudes are investigated. It seems that the temporal variation of rotation rates should be related to the solar cycle phase. The rotation profile of magnetic fields is obtained: the sidereal rotation rates decrease from the equator to mid-latitude and reach their minimum values of about 13.16 deg day{sup -1} (13.17 deg day{sup -1}) at 53 Degree-Sign (54 Degree-Sign ) latitude in the northern (southern) hemisphere, then increase toward higher latitudes. This rotation profile is different from the differential rotation law obtained by Snodgrass from a cross-correlation analysis of daily magnetograms, in which the rotation rates show a steep decrease from the equator to the poles. However, it is much closer to the quasi-rigid rotation law derived by Stenflo from an auto-correlation analysis of daily magnetograms. Some possible interpretations are discussed for the resulting rotation profile.

  7. Discovery of Eight Recycled Pulsars - The Swinburne Intermediate Latitude Pulsar Survey

    E-Print Network [OSTI]

    R. T. Edwards

    1999-11-19T23:59:59.000Z

    We have conducted a pulsar survey of intermediate Galactic latitudes (15deg 0.57 Mo and > 1.2 Mo), while anotherhas a low mass (~0.2 Mo) companion in a 23.3-d orbit, residing the well-known orbital period ``gap''.

  8. A LARGE-AREA SURVEY FOR RADIO PULSARS AT HIGH GALACTIC LATITUDES

    SciTech Connect (OSTI)

    Jacoby, B. A.; Kulkarni, S. R. [Department of Astronomy, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Bailes, M.; Ord, S. M. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Hawthorn, VIC 31122 (Australia); Edwards, R. T. [Australia Telescope National Facility, CSIRO, P.O. Box 76, Epping, NSW 1710 (Australia)], E-mail: baj@astro.caltech.edu, E-mail: srk@astro.caltech.edu, E-mail: mbailes@swin.edu.au, E-mail: ord@physics.usyd.edu.au, E-mail: Russell.Edwards@csiro.au

    2009-07-10T23:59:59.000Z

    We have completed a survey for pulsars at high Galactic latitudes with the 64 m Parkes radio telescope. Observing with the 13 beam multibeam receiver at a frequency of 1374 MHz, we covered {approx}4150 square degrees in the region -100 deg. {<=} l {<=} 50 deg., 15 deg. {<=} |b| {<=} 30 deg. with 7232 pointings of 265 s each, thus extending the Swinburne Intermediate Latitude Pulsar Survey a further 15 deg. on either side of the Galactic plane. The signal from each beam was processed by a 96 channel x 3 MHz x 2 polarization filterbank, with the detected power in the two polarizations of each frequency channel summed and digitized with 1 bit sampling every 125 {mu}s, giving good sensitivity to millisecond pulsars with low or moderate dispersion measure. The resulting 2.4 TB data set was processed using standard pulsar search techniques with the workstation cluster at the Swinburne Centre for Astrophysics and Supercomputing. This survey resulted in the discovery of 26 new pulsars including seven binary and/or millisecond pulsars, and redetected 36 previously known pulsars. We describe the survey methodology and results, and present timing solutions for the 19 newly discovered slow pulsars, as well as for nine slow pulsars discovered the Swinburne Intermediate Latitude Pulsar Survey that had no previous timing solutions. Even with a small sampling interval, 1374 MHz center frequency, and a large mid-latitude survey volume we failed to detect any very rapidly spinning pulsars. Evidently, such 'submillisecond' pulsars are rare.

  9. Analyzing and simulating the variability of solar irradiance and solar PV powerplants

    E-Print Network [OSTI]

    Lave, Matthew S.

    2012-01-01T23:59:59.000Z

    Optimum tilt of a solar collector, Solar & Wind Technology,and orientation for solar collector in Brunei Darussalam,Optimum tilt angle for solar collectors. , Energy Sources,

  10. High-power, low-lateral divergence broad area quantum cascade lasers with a tilted front facet

    SciTech Connect (OSTI)

    Ahn, Sangil, E-mail: sangil.ahn@tuwien.ac.at; Schwarzer, Clemens; Zederbauer, Tobias; MacFarland, Donald C.; Detz, Hermann; Andrews, Aaron M.; Schrenk, Werner; Strasser, Gottfried [Institute for Solid State Electronics, Vienna University of Technology, 1040 Vienna (Austria)

    2014-02-03T23:59:59.000Z

    We introduce a simple technique to improve the beam quality of broad area quantum cascade lasers. Moderately tilted front facets of the laser provide suppression of higher order lateral waveguide modes. A device with a width of 60??m and a front facet angle of 17° shows a nearly diffraction limited beam profile. In addition, the peak output power and the slope efficiency of the device are increased since most of the light inside the cavity is emitted through the tilted front facet by an asymmetric light intensity distribution along the cavity.

  11. Seasonal dependence of localized, high-latitude dayside aurora H. U. Frey, N. stgaard, and T. J. Immel

    E-Print Network [OSTI]

    California at Berkeley, University of

    Seasonal dependence of localized, high-latitude dayside aurora (HiLDA) H. U. Frey, N. Østgaard frequently observes intense ultraviolet (UV) emissions from a localized High Latitude Dayside Aurora (HiLDA) poleward of the general auroral oval location [Frey et al., 2003a]. It has been shown that this aurora

  12. Polarization-resolved sensing with tilted fiber Bragg gratings: theory and limits of detection

    E-Print Network [OSTI]

    Bialiayeu, Aliaksandr; Albert, Jacques

    2015-01-01T23:59:59.000Z

    Polarization based sensing with tilted fiber Bragg grating (TFBG) sensors is analysed theoretically by two alternative approaches. The first method is based on tracking the grating transmission for two orthogonal states of linear polarized light that are extracted from the measured Jones matrix or Stokes vectors of the TFBG transmission spectra. The second method is based on the measurements along the system principle axes and polarization dependent loss (PDL) parameter, also calculated from measured data. It is shown that the frequent crossing of the Jones matrix eigenvalues as a function of wavelength leads to a non-physical interchange of the calculated principal axes; a method to remove this unwanted mathematical artefact and to restore the order of the system eigenvalues and the corresponding principal axes is provided. A comparison of the two approaches reveals that the PDL method provides a smaller standard deviation and therefore lower limit of detection in refractometric sensing. Furthermore, the pol...

  13. Three-dimensional microelectromechanical tilting platform operated by gear-driven racks

    DOE Patents [OSTI]

    Klody, Kelly A.; Habbit Jr., Robert D.

    2005-11-01T23:59:59.000Z

    A microelectromechanical (MEM) tiltable-platform apparatus is disclosed which utilizes a light-reflective platform (i.e. a micromirror) which is supported above a substrate by flexures which can be bent upwards to tilt the platform in any direction over an angle of generally .+-.10 degrees using a gear-driven rack attached to each flexure. Each rack is driven by a rotary microengine (i.e. a micromotor); and an optional thermal actuator can be used in combination with each microengine for initially an initial uplifting of the platform away from the substrate. The MEM apparatus has applications for optical switching (e.g. between a pair of optical fibers) or for optical beam scanning.

  14. Design, Fabrication, and Test of a Superconducting Dipole Magnet Based on Tilted Solenoids

    SciTech Connect (OSTI)

    Caspi, S.; Dietderich, D. R.; Ferracin, P.; Finney, N. R.; Fuery, M. J.; Gourlay, S. A.; Hafalia, A. R.

    2007-06-01T23:59:59.000Z

    It can be shown that, by superposing two solenoid-like thin windings that are oppositely skewed (tilted) with respect to the bore axis, the combined current density on the surface is 'cos-theta' like and the resulting magnetic field in the bore is a pure dipole. As a proof of principle, such a magnet was designed, built and tested as part of a summer undergraduate intern project. The measured field in the 25mm bore, 4 single strand layers using NbTi superconductor, exceeded 1 T. The simplicity of this high field quality design, void of typical wedges end-spacers and coil assembly, is especially suitable for insert-coils using High Temperature Superconducting wire as well as for low cost superconducting accelerator magnets for High Energy Physics. Details of the design, construction and test are reported.

  15. Tilt and running of cosmological observables in generalized single-field inflation

    SciTech Connect (OSTI)

    Bartolo, Nicola; Matarrese, Sabino [Dipartimento di Fisica ''G. Galilei'', Università degli Studi di Padova, via Marzolo 8, I-35131 Padova (Italy); Fasiello, Matteo [Dipartimento di Fisica ''G. Occhialini'', Università degli Studi di Milano Bicocca and INFN, Sezione di Milano Bicocca, Piazza della Scienza 3, I-20126 Milano (Italy); Riotto, Antonio, E-mail: nicola.bartolo@pd.infn.it, E-mail: matteo.fasiello@mib.infn.it, E-mail: sabino.matarrese@pd.infn.it, E-mail: riotto@mail.cern.ch [INFN, Sezione di Padova, via Marzolo 8, I-35131 Padova (Italy)

    2010-12-01T23:59:59.000Z

    Employing an effective field theory approach to inflationary perturbations, we analyze in detail the effect of curvature-generated Lagrangian operators on various observables, focusing on their running with scales. At quadratic order, we solve the equation of motion at next-to-leading leading order in a generalized slow-roll approximation for a very general theory of single-field inflation. We derive the resulting power spectrum, its tilt and running. We then focus on the contribution to the primordial non-Gaussianity amplitude f{sub NL} sourced by a specific interaction term. We show that the running of f{sub NL} can be substantially larger than what dictated by the slow-roll parameters.

  16. Examining the Impact of Pad Flexibility on the Rotordynamic Coefficients of Rocker-Pivot-Pad Tilting-Pad Journal Bearings

    E-Print Network [OSTI]

    Gaines, Jennifer Elizabeth

    2014-12-03T23:59:59.000Z

    Measured and predicted static and dynamic load characteristics are provided for a three-pad, rocker-pivot, tilting-pad journal bearing in the load-between-pad orientation. The bearing has the following characteristics: 3 pads, .50 pad pivot offset...

  17. Rotordynamic coefficients for a load-between-pad, flexible-pivot tilting pad bearing at high loads

    E-Print Network [OSTI]

    Hensley, John Eric

    2006-10-30T23:59:59.000Z

    The dynamic and static performance of a flexure-pivot tilting pad bearing is presented at a load between pad configuration for various load and speed combinations. A similar work performed on the same bearing at lower loads ranging from 0-1 MPa (0...

  18. Dynamic and Static Characteristics of a Rocker-Pivot, Tilting-Pad Bearing with 50% and 60% Offsets.

    E-Print Network [OSTI]

    Kulhanek, Chris David

    2012-02-14T23:59:59.000Z

    Static performance and rotordynamic coefficients are provided for a rocker-pivot, tilting-pad journal bearing with 50 and 60 percent offset pads in a load-between-pad configuration. The bearing uses leading-edge-groove lubrication and has...

  19. Tilted Brownian Ratchet for DNA Analysis Lotien Richard Huang, Edward C. Cox, Robert H. Austin,*, and James C. Sturm

    E-Print Network [OSTI]

    Tilted Brownian Ratchet for DNA Analysis Lotien Richard Huang, Edward C. Cox, Robert H. Austin of fractionation of 100-kb DNA molecules in Brownian ratchet arrays. In our device, the electrophoretic flow a higher fraction of the diffusing molecules is "ratcheted" at each step in the array. Molecules of lengths

  20. Influence of a longitudinal and tilted vibration on stability and dewetting of a liquid film S. Shklyaev,1

    E-Print Network [OSTI]

    Khenner, Mikhail

    that the viscosity is important only in a thin boundary layer near the rigid wall 5,6 . This approximation works well or a tilted vibration. Using a multiscale technique we split the film motion into the oscillatory essential for the oscillatory motion. Applying the lubrication approximation for the averaged motion we

  1. A study of mid-latitude tropopause characteristics over eastern North America

    E-Print Network [OSTI]

    Houston, Ben Howard

    1962-01-01T23:59:59.000Z

    50 40 30 20 10 MO BUP PLT GSO 60 55 50 45 40 35 30 25 Latitude (degrees north) Figure l. Occurrence of multiple tropopauses during summer 120 IJ III 0 0 0 E 0 0 '0 N 4J 0 A N 0 100 80 60 40 20 E I CI CI -20 60 55 50 45... 40 35 30 25 Latitude (degrees north) Figure 2. Profile of mean zonal wind during summer 21 70 C 4I 0 o e e o, o o IU O N lJ o e W m 0 o 4J 4J C m Ol v 6 u Ol CI 60 50 40 30 20 10 PH NO BUF 0 SO P T 60 55 50 45 40 35...

  2. Multi-Year Lags between Forest Browning and Soil Respiration at High Northern Latitudes

    SciTech Connect (OSTI)

    Bond-Lamberty, Benjamin; Bunn, Andrew G.; Thomson, Allison M.

    2012-11-26T23:59:59.000Z

    High-latitude northern ecosystems are experiencing rapid climate changes, and represent a large potential climate feedback because of their high soil carbon densities and shifting disturbance regimes. A significant carbon flow from these ecosystems is soil respiration (RS, the flow of carbon dioxide, generated by plant roots and soil fauna, from the soil surface to atmosphere), and any change in the high-latitude carbon cycle might thus be reflected in RS observed in the field. This study used two variants of a machine-learning algorithm and least squares regression to examine how remotely-sensed canopy greenness (NDVI), climate, and other variables are coupled to annual RS based on 105 observations from 64 circumpolar sites in a global database. The addition of NDVI roughly doubled model performance, with the best-performing models explaining ~62% of observed RS variability

  3. An analysis on the mid-latitude scintillation and coherence frequency bandwidth using transionospheric VHF signals

    SciTech Connect (OSTI)

    Juang, Zhen [Los Alamos National Laboratory; Roussel-dupre, Robert [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    An analysis was perfonned on the mid-latitude scintillation and coherence frequency bandwidth (Fcoh) using transionospheric VHF signal data. The data include 1062 events spanning from November 1997 to June 2002. Each event records FORTE satellite received VHF signals from LAPP located at Los Alamos, New Mexico. Fcohs were derived to study scintillation characteristics on diurnal and seasonal variations, as well as changes due to solar and geomagnetic activities. Comparisons to the VHFIUHF coherence frequency bandwidth studies previously reported at equatorial and mid-latitude regions are made using a 4th power frequency dependence relationship. Furthennore, a wideband ionospheric scintillation model, WBMOD, was used to estimate Fcohs and compared with our VHF Fcoh values. Our analysis indicates mid-latitude scintillation characteristics that are not previously revealed. At the VHF bottom frequency range (3035 MHz), distinguished smaller Fcohs are found in time period from sunset to midnight, in wann season from May to August, and in low solar activity years. The effects of geomagnetic storm activity on Fcoh are characterized by a sudden transition at a Kp index of 50-60. Comparisons with median Fcohs estimated from other studies validated our VHF Fcohs for daytime while an order of magnitude larger Fcohs are found for nighttime, implying a time-dependent issue in applying the 4th order power relationship. Furthermore, comparisons with WBMOD-estimated Fcohs indicated generally matched median scintillation level estimates while differences do exist for those events undergoing high geomagnetic stonn activity which may imply underestimates of scintillation level by the WBMOD in the mid-latitude regions.

  4. Impact of rising greenhouse gases on mid-latitude storm tracks and associated hydroclimate variability and change

    SciTech Connect (OSTI)

    Seager, Richard

    2014-12-08T23:59:59.000Z

    Project Summary This project aimed to advance physical understanding of how and why the mid-latitude jet streams and storm tracks shift in intensity and latitude in response to changes in radiative forcing with an especial focus on rising greenhouse gases. The motivation, and much of the work, stemmed from the importance that these mean and transient atmospheric circulation systems have for hydroclimate. In particular drying and expansion of the subtropical dry zones has been related to a poleward shift of the mid-latitude jets and storm tracks. The work involved integrated assessment of observation and model projections as well as targeted model simulations.

  5. Low-latitude Western North Atlantic climate variability during the past millennium : insights from proxies and models

    E-Print Network [OSTI]

    Saenger, Casey Pearce

    2009-01-01T23:59:59.000Z

    Estimates of natural climate variability during the past millennium provide a frame of reference in which to assess the significance of recent changes. This thesis investigates new methods of reconstructing low-latitude ...

  6. Uncertainty analysis of vegetation distribution in the northern high latitudes during the 21st century with a dynamic vegetation model

    E-Print Network [OSTI]

    Jiang, Yueyang

    This study aims to assess how high-latitude vegetation may respond under various climate scenarios during the 21st century with a focus on analyzing model parameters induced uncertainty and how this uncertainty compares ...

  7. Experimental frequency-dependent rotordynamic coefficients for a load-on-pad, high-speed, flexible-pivot tilting-pad bearing

    E-Print Network [OSTI]

    Rodriguez Colmenares, Luis Emigdio

    2004-09-30T23:59:59.000Z

    This thesis provides experimental frequency dependent stiffness and damping coefficient results for a high-speed, lightly loaded, flexible-pivot tilting-pad bearing, with a load-on-pad configuration. Test conditions include four shaft speeds (6000...

  8. Static characteristics and rotordynamic coefficients of a four-pad tilting-pad journal bearing with ball-in-socket pivots in load-between-pad configuration

    E-Print Network [OSTI]

    Harris, Joel Mark

    2009-05-15T23:59:59.000Z

    Static characteristics and rotordynamic coefficients were experimentally determined for a four-pad tilting-pad journal bearing with ball-in-socket pivots in loadbetween- pad configuration. A frequency-independent [M]-[C]-[K] model fit...

  9. vy physical work). Some white-collar jobs may share these characteris-tics, but these factors overwhelmingly tilt toward blue-collar occupations.

    E-Print Network [OSTI]

    Holsinger, Kent

    overwhelmingly tilt toward blue-collar occupations. Often blue-collar jobs tend to be dirty, dangerous, and of a confiscated driver's license. Loaning money and covering for behav- ioral problems are also not uncommon. Some

  10. Unique determination of the -CN group tilt angle in Langmuir monolayers using sum-frequency polarization null angle and phase

    SciTech Connect (OSTI)

    Velarde Ruiz Esparza, Luis A.; Wang, Hongfei

    2013-10-14T23:59:59.000Z

    The relative phase and amplitude ratio between the ssp and ppp polarization combinations of the vibrational sum-frequency generation (SFG) response can be uniquely and accurately determined by the polarization null angle (PNA) method. In this report we show that PNA measurements of the -CN vibration in the 4-n pentyl-4'-cyanoterphenyl (5CT) Langmuir monolayer at the air/water interface yields ssp and ppp response of the same phase, while those in the 4-n-octyl-4'cyanobiphenyl (8CB) Langmuir monolayer have the opposite phase. Accordingly, the -CN group in the 5CT monolayer is tilted around 25+/-2 from the interface normal, while that in the 8CB is tilted around 57+/-2, consistent with the significant differences in the phase diagrams and hydrogen bonding SFG spectra of the two Langmuir monolayers as reported in the literature. These results also demonstrate that in SFG studies the relative phase information of the different polarization combinations, especially for the ssp and ppp, is important in the unique determination of the tilt angle and conformation of a molecular group at the interface.

  11. Simulations of dislocation pile-ups at assymetric tilt boundaries in aluminum

    SciTech Connect (OSTI)

    Valone, Steven [Los Alamos National Laboratory; Wang, Jian M [Los Alamos National Laboratory; Hoagland, Richard C [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory

    2011-01-21T23:59:59.000Z

    Materials deformation processes are increasingly approachable through the both conventional and accelerated molecular dynamics. In one deformation process, dislocation pile-up at a grain boundary, a greater understanding is required as to how dislocations transmit through grain boundaries, causing plastic deformation, or reflect and reconstruct the grain boundary, but with no macroscopic deformation. Here dislocation pile-ups in an alwninum bicrystal with an asymmetric tilt grain boundary are simulated atomistically, introducing effects of dislocation interactions beyond linear elastic ones. The observed responses as functions of the number of explicitly modeled dislocations and the magnitude of the applied stress are discussed. Typical conditions for the simulations consist of thermal relaxation room temperature, five active dislocations inserted within a 6.5-million-atom cell, and an additional fourteen dislocations represented within the atomistic simulation by their elastic strain fields. The dislocations are initially distributed according to linear elastic estimates of their positions in a double-ended pile-up from a chosen far-field stress. The whole cell is allowed to relax according to a procedure to be described. In the ensuing simulations, the system is propagated for some substantial period of time (lOs of ps), followed by small increments of strain. After a number of such increments, we observe all of the anticipated events. Usually several of the closest dislocations are absorbed into the grain boundary, resulting in varying amounts of reconstruction. Reflections from the boundary are common and show a strong dependence on sample thickness. Transmission events are seen on both slip systems in the other grain. The particulars of these events will be described as well.

  12. Birkeland currents and charged particles in the high-latitude prenoon region: A new interpretation

    SciTech Connect (OSTI)

    Bythrow, P.F.; Potemra, T.A.; Erlandson, R.E.; Zanetti, L.J.; Klumpar, D.M.

    1988-09-01T23:59:59.000Z

    Simultaneous, conjugate measurements of magnetic fields and charged particles at low altitude in the high-latitude prenoon sector and the magnetosheath were made with the DMSP F7, HILAT, and Active Magnetospheric Particle Tracer Explorers (AMPTE) CCE satellites on November 1, 1984. These data show that the low-latitude portion of the traditional ''cusp'' particle signature is coincident with the prenoon region 1 current system in both hemispheres and for both northward and southward interplanetary magnetic fields (IMF). The traditional ''cusp'' Birkeland currents are associated with the dispersion region of cusp ions when the IMF is directed southward and with electron fluxes that are slightly enhanced over polar rain intensities. Finally, electron spectra measured by AMPTE CCE in the magnetosheath near 1000 MLT are similar in shape and energy to those acquired at low altitude by both DMSP F7 and HILAT. These observations indicate that for both northward and southward IMF, the traditional ''cusp particle'' signature is coincident with the region 1 Birkeland current system and maps to low altitude along field lines that thread the dayside boundary layer. The traditional ''cusp'' Birkeland current system flows along field lines that lie poleward of the region of cusp particles and the region 1 current system. These field lines thread the plasma mantle. Thus, we suggest that the traditional ''cusp'' current system might be appropriately renamed the ''mantle'' Birkeland current system. copyright American Geophysical Union 1988

  13. Proton irradiation effect on SCDs

    E-Print Network [OSTI]

    Yan-Ji Yang; Jing-Bin Lu; Yu-Sa Wang; Yong Chen; Yu-Peng Xu; Wei-Wei Cui; Wei Li; Zheng-Wei Li; Mao-Shun Li; Xiao-Yan Liu; Juan Wang; Da-Wei Han; Tian-Xiang Chen; Cheng-Kui Li; Jia Huo; Wei Hu; Yi Zhang; Bo Lu; Yue Zhu; Ke-Yan Ma; Di Wu; Yan Liu; Zi-Liang Zhang; Guo-He Yin; Yu Wang

    2014-04-19T23:59:59.000Z

    The Low Energy X-ray Telescope is a main payload on the Hard X-ray Modulation Telescope satellite. The swept charge device is selected for the Low Energy X-ray Telescope. As swept charge devices are sensitive to proton irradiation, irradiation test was carried out on the HI-13 accelerator at the China Institute of Atomic Energy. The beam energy was measured to be 10 MeV at the SCD. The proton fluence delivered to the SCD was $3\\times10^{8}\\mathrm{protons}/\\mathrm{cm}^{2}$ over two hours. It is concluded that the proton irradiation affects both the dark current and the charge transfer inefficiency of the SCD through comparing the performance both before and after the irradiation. The energy resolution of the proton-irradiated SCD is 212 eV@5.9 keV at $-60\\,^{\\circ}\\mathrm{C}$, while it before irradiated is 134 eV. Moreover, better performance can be reached by lowering the operating temperature of the SCD on orbit.

  14. THE HIGH-LATITUDE BRANCH OF THE SOLAR TORSIONAL OSCILLATION IN THE RISING PHASE OF CYCLE 24

    SciTech Connect (OSTI)

    Howe, R. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Christensen-Dalsgaard, J. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Ny Munkegade 120, Aarhus University, DK-8000 Aarhus C (Denmark); Hill, F.; Komm, R. [National Solar Observatory, P.O. Box 26732, Tucson, AZ 85726-6732 (United States); Larson, T. P.; Schou, J. [HEPL Solar Physics, 452 Lomita Mall, Stanford University, Stanford, CA 94305-4085 (United States); Rempel, M.; Thompson, M. J., E-mail: rhowe@nso.edu [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

    2013-04-10T23:59:59.000Z

    We use global heliseismic data from the Global Oscillation Network Group, the Michelson Doppler Imager on board the Solar and Heliospheric Observatory, and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, to examine the behavior, during the rising phase of Solar Cycle 24, of the migrating zonal flow pattern known as the torsional oscillation. Although the high-latitude part of the pattern appears to be absent in the new cycle when the flows are derived by subtracting a mean across a full solar cycle, it can be seen if we subtract the mean over a shorter period in the rising phase of each cycle, and these two mean rotation profiles differ significantly at high latitudes. This indicates that the underlying high-latitude rotation has changed; we speculate that this is in response to weaker polar fields, as suggested by a recent model.

  15. Uranium vacancy mobility at the sigma 5 symmetric tilt grain boundary in UO2

    SciTech Connect (OSTI)

    Uberuaga, Blas P. [Los Alamos National Laboratory

    2012-05-02T23:59:59.000Z

    An important consequence of the fissioning process occurring during burnup is the formation of fission products. These fission products alter the thermo-mechanical properties of the fuel. They also lead to macroscopic changes in the fuel structure, including the formation of bubbles that are connected to swelling of the fuel. Subsequent release of fission gases increase the pressure in the plenum and can cause changes in the properties of the fuel pin itself. It is thus imperative to understand how fission products, and fission gases in particular, behave within the fuel in order to predict the performance of the fuel under operating conditions. Fission gas redistribution within the fuel is governed by mass transport and the presence of sinks such as impurities, dislocations, and grain boundaries. Thus, to understand how the distribution of fission gases evolves in the fuel, we must understand the underlying transport mechanisms, tied to the concentrations and mobilities of defects within the material, and how these gases interact with microstructural features that might act as sinks. Both of these issues have been addressed in previous work under NEAMS. However, once a fission product has reached a sink, such as a grain boundary, its mobility may be different there than in the grain interior and predicting how, for example, bubbles nucleate within grain boundaries necessitates an understanding of how fission gases diffuse within boundaries. That is the goal of the present work. In this report, we describe atomic level simulations of uranium vacancy diffusion in the pressence of a {Sigma}5 symmetric tilt boundary in urania (UO{sub 2}). This boundary was chosen as it is the simplest of the boundaries we considered in previous work on segregation and serves as a starting point for understanding defect mobility at boundaries. We use a combination of molecular statics calculations and kinetic Monte Carlo (kMC) to determine how the mobility of uranium vacancies is altered at this particular grain boundary. Given that the diffusion of fission gases such as Xe are tied to the mobility of uranium vacancies, these results given insight into how fission gas mobility differs at grain boundaries compared to bulk urania.

  16. Petrology of a dredged cumulate-textured gabboric complex from the mid-Atlantic ridge, latitude 26?N

    E-Print Network [OSTI]

    Tiezzi, Lawrence James

    1977-01-01T23:59:59.000Z

    PETROLOGY OF A DREDGED CUNULATE- '"EXTURED GABI3ROIC COMPLEX FROM THE MID-ATLANTIC RIDGE, LATITUDE 26 N 0 A Thesis LAWRENCE JAMES Ti'ZZI Submitted to the Graduate Ccilec;e of Texas A&M University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1977 Majo- Subject: Geology PETROLOGY OF A DREDGED CUNULATE- TEXTURED GABBROIC CONPLEX FROM o THE NID-ATLANTIC RIDGE, LATITUDE 26 N A Thesis by LAWRENCE JAMES TIEZZI Approved as to style and content by...

  17. Atick-Witten Hagedorn Conjecture, near scale-invariant matter and blue-tilted gravity power spectrum

    E-Print Network [OSTI]

    Tirthabir Biswas; Tomi Koivisto; Anupam Mazumdar

    2014-05-03T23:59:59.000Z

    We will provide an interesting new mechanism to generate almost scale invariant seed density perturbations with a red spectrum, while keeping the gravitational wave spectrum blue-tilted in a stringy thermal contracting phase at temperatures beyond the Hagedorn temperature. This phase is often referred to as the Hagedorn phase where the free energy has been conjectured by Atick and Witten to grow more slowly than ordinary radiation. The primordial fluctuations are created by the statistical thermal fluctuations determined by the partition function, rather than quantum vacuum driven fluid dynamical fluctuations. In order for our mechanism to work we require a non-singular bouncing cosmology.

  18. GHIGLS: HI mapping at intermediate Galactic latitude using the Green Bank Telescope

    E-Print Network [OSTI]

    Martin, P G; Goncalves, D Pinheiro; Lockman, Felix J; Boothroyd, A I; Miville-Deschenes, M -A; Joncas, G; Stephan, G

    2015-01-01T23:59:59.000Z

    This paper introduces the data cubes from GHIGLS, our deep Green Bank Telescope surveys of the 21-cm line emission of HI in targeted fields at intermediate Galactic latitude. The GHIGLS fields together cover over 800 square degrees at 9.55' spatial resolution. The HI spectra have an effective velocity resolution about 1.0 km/s and cover at least -450 power spectra of maps of the column density, NHI. For our featured representative field, centered on the North Ecliptic Pole, the scaling exponents in power-law representations of the power spectra of NHI maps for low, intermediate, and high velocity gas components (LVC, IVC, and HVC) are -2.90 +/- 0.03, -2.55 +/- 0.04, and -2.66 +/- 0.06, respectively. After Gaussian decomposition of the line profiles, NHI maps were also made corresponding to the broad and narrow line components in the LVC...

  19. The Mid-latitude Continental Convective Clouds (MC3E) Experiment Final Campaign Report

    SciTech Connect (OSTI)

    Jensen, Michael [Brookhaven National Laboratory; Kollias, Pavlos [McGill University; Giangrande, Scott

    2014-04-01T23:59:59.000Z

    The Mid-latitude Continental Convective Clouds Experiment (MC3E) took place from April 22 through June 6, 2011, centered at the ARM Southern Great Plains site (http://www.arm.gov/sites/sgp) in northcentral Oklahoma. MC3E was a collaborative effort between the ARM Climate Research Facility and the National Aeronautics and Space Administration’s (NASA’s) Global Precipitation Measurement (GPM) mission Ground Validation (GV) program. The campaign leveraged the largest ground-based observing infrastructure available in the central United States, including recent upgrades through the American Recovery and Reinvestment Act of 2009, combined with an extensive sounding array, remote sensing and in situ aircraft observations, and additional radar and in situ precipitation instrumentation. The overarching goal of the campaign was to provide a three-dimensional characterization of convective clouds and precipitation for the purpose of improving the representation of convective lifecycle in atmospheric models and the reliability of satellite-based retrievals of precipitation.

  20. Neutron irradiation of beryllium pebbles

    SciTech Connect (OSTI)

    Gelles, D.S.; Ermi, R.M. [Pacific Northwest National Lab., Richland, WA (United States); Tsai, H. [Argonne National Lab., IL (United States)

    1998-03-01T23:59:59.000Z

    Seven subcapsules from the FFTF/MOTA 2B irradiation experiment containing 97 or 100% dense sintered beryllium cylindrical specimens in depleted lithium have been opened and the specimens retrieved for postirradiation examination. Irradiation conditions included 370 C to 1.6 {times} 10{sup 22} n/cm{sup 2}, 425 C to 4.8 {times} 10{sup 22} n/cm{sup 2}, and 550 C to 5.0 {times} 10{sup 22} n/cm{sup 2}. TEM specimens contained in these capsules were also retrieved, but many were broken. Density measurements of the cylindrical specimens showed as much as 1.59% swelling following irradiation at 500 C in 100% dense beryllium. Beryllium at 97% density generally gave slightly lower swelling values.

  1. Statistical criteria for characterizing irradiance time series.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Ellis, Abraham; Hansen, Clifford W.

    2010-10-01T23:59:59.000Z

    We propose and examine several statistical criteria for characterizing time series of solar irradiance. Time series of irradiance are used in analyses that seek to quantify the performance of photovoltaic (PV) power systems over time. Time series of irradiance are either measured or are simulated using models. Simulations of irradiance are often calibrated to or generated from statistics for observed irradiance and simulations are validated by comparing the simulation output to the observed irradiance. Criteria used in this comparison should derive from the context of the analyses in which the simulated irradiance is to be used. We examine three statistics that characterize time series and their use as criteria for comparing time series. We demonstrate these statistics using observed irradiance data recorded in August 2007 in Las Vegas, Nevada, and in June 2009 in Albuquerque, New Mexico.

  2. What is this MCMS? MCMS stands for the MAP Climatology of Mid-latitude Storminess dataset (see

    E-Print Network [OSTI]

    arguments. Cyclone tracking is treated as a separate process and product (not shown here for brevity) depression around a mid-latitude baroclinic cyclone (or just cyclone). MCMS rests on two operations: 1) finding and tracking cyclones and 2) objectively delineating the area under each cyclones influence

  3. Latitude, seed predation and seed mass A. T. Moles* and M. Westoby Department of Biological Sciences, Macquarie University,

    E-Print Network [OSTI]

    Moles, Angela

    of species from around the world. We also aimed to quantify the slope and predictive power expected that herbivory and predation might be more sustained threats there. Considerable evidence supports winter browsing intensity and latitude across six species of woody plants (Swihart & Bryant, 2001

  4. Operational taxonomy and (paleo-)autecology of round, brown, spiny dinoflagellate cysts from the Quaternary of high northern latitudes

    E-Print Network [OSTI]

    Pedersen, Tom

    Operational taxonomy and (paleo-)autecology of round, brown, spiny dinoflagellate cysts from determination key taxonomy paleoecology Round brown spiny dinoflagellate cysts from high latitudes a synthesis of descriptions with remarks on the mor- phology, taxonomy, nomenclature and ecology of cysts from

  5. SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH A SOLAR CYCLE

    E-Print Network [OSTI]

    Richardson, John

    SOLAR WIND HELIUM ABUNDANCE AS A FUNCTION OF SPEED AND HELIOGRAPHIC LATITUDE: VARIATION THROUGH of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind theoretical work in which enhancements of coronal helium lead to stagnation of the escaping proton flux

  6. Putting plant resistance traits on the map: a test of the idea that plants are better defended at lower latitudes

    E-Print Network [OSTI]

    at lower latitudes Angela T. Moles1,2,3,4 , Ian R. Wallis3 , William J. Foley3 , David I. Warton5 , James C Biology, James Cook University, PO Box 6811,Cairns, Australia; 12 NationalEnvironmental Research InstituteSciences, University of Zambia, PO Box 32379, Lusaka 10101, Zambia;18 School of Marine and Tropical Biology, James Cook

  7. A jet streak circulation associated with a low-latitude jet in the Southern Hemisphere over Africa.

    E-Print Network [OSTI]

    Nicholson, Sharon E.

    A jet streak circulation associated with a low-latitude jet in the Southern Hemisphere over Africa 2007 #12;2 Abstract In the Southern Hemisphere over Africa a mid-tropospheric easterly jet stream exists during some months that is analogous to the African Easterly Jet over West Africa. In this note

  8. Determination of the optimum inclination of a flat solar collector in function of latitude and local climatic data

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    569 Determination of the optimum inclination of a flat solar collector in function of latitude of a solar collector, it is necessary to reduce its size to a minimum for a given collected energy of equations described in this work were developed to determine the inclination angle of a . flat solar

  9. Low temperature irradiation tests on

    E-Print Network [OSTI]

    McDonald, Kirk

    Sample cool down by He gas loop 10K ­ 20K Fast neutron flux Measured by Ni activation in 2010 1.4xK #12;reactor Cryogenics #12;Al-Cu-Mg He gas temperature near sample 12K Resistance changesLow temperature irradiation tests on stabilizer materials using reactor neutrons at KUR Makoto

  10. sterilization by irradiation Arne Miller

    E-Print Network [OSTI]

    -1:2006 Equipment characterization (6) Product definition (7) Process definition (8) Installation Qualification (9.1) Operational Qualification (9.2) · Performance Qualification (9.3) - later #12;3 Equipment characterization samples shall be irradiated to defined and uniform doses. #12;9 9.1 Installation qualification (A.9

  11. Occlusion-Aware Hessians for Error Control in Irradiance Caching /

    E-Print Network [OSTI]

    Schwarzhaupt, Jorge Andres

    2013-01-01T23:59:59.000Z

    Control for Irradiance Caching. ” In ACM Transactions on Graphics,Control for Irradiance Caching. ” In ACM Transactions on Graphics,

  12. Possibility for irradiated beryllium at CERN

    E-Print Network [OSTI]

    McDonald, Kirk

    Possibility for irradiated beryllium at CERN RaDIATE meeting, 22nd July 2013 M. Calviani (CERN ­ Engineering Department ­ Sources, Target and Interactions Group) #12;Irradiated beryllium at CERN 2 Two possibilities exists at CERN to obtain irradiated beryllium for testing: beam windows, and in particular

  13. Irradiation-induced phenomena in carbon

    E-Print Network [OSTI]

    Krasheninnikov, Arkady V.

    Chapter 1 Irradiation-induced phenomena in carbon nanotubes To appear in "Chemistry of Carbon@acclab.helsinki.fi 1 #12;2CHAPTER 1. IRRADIATION-INDUCED PHENOMENA IN CARBON NANOTUBES #12;Contents 1 Irradiation-induced phenomena in carbon nanotubes 1 1.1 Introduction

  14. Reconciliation of local and long range tilt correlations in underdoped La??xBaxCuO? (0 ? x ? 0.155)

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

    Bozin, Emil S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhong, Ruidan [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Knox, Kevin R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, John P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tranquada, John M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Billinge, Simon J. L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Columbia Univ., New York, NY (United States)

    2015-02-01T23:59:59.000Z

    A long standing puzzle regarding the disparity of local and long range CuO? octahedral tilt correlations in the underdoped regime of La??xBaxCuO? is addressed by utilizing complementary neutron powder diffraction and inelastic neutron scattering (INS) approaches. Long-range and static CuO? tilt order with orthogonally inequivalent Cu-O bonds in the CuO? planes in the low temperature tetragonal (LTT) phase is succeeded on warming through the low-temperature transition by one with orthogonally equivalent bonds in the low temperature orthorhombic (LTO) phase. In contrast, the signatures of LTT-type tilts in the instantaneous local atomic structure persist on heating throughout the LTO crystallographic phase on the nanoscale, although becoming weaker as temperature increases. Analysis of the INS spectra for the x = 1/8 composition reveals the dynamic nature of the LTT-like tilt fluctuations within the LTO phase and their 3D character. The doping dependence of relevant structural parameters indicates that the magnitude of the Cu-O bond anisotropy has a maximum at x = 1/8 doping where bulk superconductivity is most strongly suppressed, suggesting that the structural anisotropy might be influenced by electron-phonon coupling and the particular stability of the stripe-ordered phase at this composition. The bond-length modulation that pins stripe order is found to be remarkably subtle, with no anomalous bond length disorder at low temperature, placing an upper limit on any in-plane Cu-O bondlength anisotropy. The results further reveal that although appreciable octahedral tilts persist through the high-temperature transition and into the high temperature tetragonal (HTT) phase, there is no significant preference between different tilt directions in the HTT regime. This study also exemplifies the importance of a systematic approach using complementary techniques when investigating systems exhibiting a large degree of complexity and subtle structural responses.

  15. Reconciliation of local and long range tilt correlations in underdoped La??xBaxCuO? (0 ? x ? 0.155)

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

    Bozin, Emil S.; Zhong, Ruidan; Knox, Kevin R.; Gu, Genda; Hill, John P.; Tranquada, John M.; Billinge, Simon J. L.

    2015-02-01T23:59:59.000Z

    A long standing puzzle regarding the disparity of local and long range CuO? octahedral tilt correlations in the underdoped regime of La??xBaxCuO? is addressed by utilizing complementary neutron powder diffraction and inelastic neutron scattering (INS) approaches. Long-range and static CuO? tilt order with orthogonally inequivalent Cu-O bonds in the CuO? planes in the low temperature tetragonal (LTT) phase is succeeded on warming through the low-temperature transition by one with orthogonally equivalent bonds in the low temperature orthorhombic (LTO) phase. In contrast, the signatures of LTT-type tilts in the instantaneous local atomic structure persist on heating throughout the LTO crystallographic phasemore »on the nanoscale, although becoming weaker as temperature increases. Analysis of the INS spectra for the x = 1/8 composition reveals the dynamic nature of the LTT-like tilt fluctuations within the LTO phase and their 3D character. The doping dependence of relevant structural parameters indicates that the magnitude of the Cu-O bond anisotropy has a maximum at x = 1/8 doping where bulk superconductivity is most strongly suppressed, suggesting that the structural anisotropy might be influenced by electron-phonon coupling and the particular stability of the stripe-ordered phase at this composition. The bond-length modulation that pins stripe order is found to be remarkably subtle, with no anomalous bond length disorder at low temperature, placing an upper limit on any in-plane Cu-O bondlength anisotropy. The results further reveal that although appreciable octahedral tilts persist through the high-temperature transition and into the high temperature tetragonal (HTT) phase, there is no significant preference between different tilt directions in the HTT regime. This study also exemplifies the importance of a systematic approach using complementary techniques when investigating systems exhibiting a large degree of complexity and subtle structural responses.« less

  16. Symmetries of migration related segments of all [001] coincidence site lattice tilt boundaries in (001) projections for all holohedral cubic materials

    SciTech Connect (OSTI)

    Moeck, Peter; York, Bryant W.; Browning, Nigel D.

    2014-09-11T23:59:59.000Z

    Utilizing bicrystallography in two dimensions (2D), the symmetries of migration related segments of Coincidence Site Lattice (CSL) boundaries are derived for projections along their [001] tilt axis in grain boundaries of crystalline materials that possess the holohedral point symmetry of the cubic system (i.e. m3m). These kinds of “edge-on” projections are typical for atomic resolution imaging of such tilt boundaries with Transmission Electron Microscopes (TEM). This fact facilitates the visual confirmation of our predictions by recently published Zcontrast scanning TEM investigations [H. Yang et al., Phil. Mag. 93 (2013) 1219] and many other TEM studies.

  17. High Latitude, Translucent Molecular Clouds as Probes of Local Cosmic Rays

    E-Print Network [OSTI]

    Abrahams, R D

    2015-01-01T23:59:59.000Z

    We analyze the gamma-ray emission from 9 high latitude, translucent molecular clouds taken with the Fermi Large Area Telescope (LAT) between 250 MeV and 10 GeV. Observations of gamma-rays allow us to probe the density and spectrum of cosmic rays in the solar neighborhood. The clouds studied lie within $\\sim\\!$270 pc from the Sun and are selected from the Planck all-sky CO map. Gamma-rays in this energy range mostly result from cosmic ray interactions with the interstellar medium, which is traced with three components: HI, CO, and dark gas. Every cloud is detected and shows significant, extended gamma-ray emission from molecular gas. The gamma-ray emission is dominated by the CO-emitting gas in some clouds, but by the CO-dark gas in others. The average emissivity and gamma-ray power law index from HI above 1 GeV shows no evidence of a systematic variation. The CO-to-H$_2$ conversion factor shows no variation between clouds over this small spatial range, but shows significant variations within each cloud. The a...

  18. Fermi Large Area Telescope Measurements of the Diffuse Gamma-Ray Emission at Intermediate Galactic Latitudes

    SciTech Connect (OSTI)

    Abdo, A.A.; /Naval Research Lab, Wash., D.C.; Ackermann, M.; Ajello, M.; /SLAC; Anderson, B.; Atwood, W.B.; /UC, Santa Cruz; Axelsson, M.; /Stockholm U. /Stockholm U., OKC; Baldini, L.; /INFN, Pisa; Ballet, J.; /DAPNIA, Saclay; Barbiellini, G.; /INFN, Trieste /Trieste U.; Bastieri, D.; /INFN, Padua /Padua U.; Baughman, B.M.; /Taiwan, Natl. Taiwan U. /Ohio State U.; Bechtol, K.; /SLAC; Bellazzini, R.; /INFN, Pisa; Berenji, B.; Blandford, R.D.; Bloom, E.D.; /SLAC; Bonamente, E.; /INFN, Perugia /Perugia U.; Borgland, A.W.; /SLAC; Bregeon, J.; Brez, A.; /INFN, Pisa; Brigida, M.; /Bari U. /INFN, Bari /Ecole Polytechnique /Washington U., Seattle /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /IASF, Milan /DAPNIA, Saclay /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Naval Research Lab, Wash., D.C. /George Mason U. /NASA, Goddard /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Perugia /Perugia U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Stockholm U. /Stockholm U., OKC /Royal Inst. Tech., Stockholm /Padua U. /Naval Research Lab, Wash., D.C. /Udine U. /INFN, Trieste /Bari U. /INFN, Bari /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /INFN, Pisa /UC, Santa Cruz /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /CENBG, Gradignan /CENBG, Gradignan /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Montpellier U. /Bari U. /INFN, Bari /Ecole Polytechnique /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Udine U. /INFN, Trieste /Hiroshima U. /Stanford U., HEPL /KIPAC, Menlo Park /SLAC /Bari U. /INFN, Bari /INFN, Pisa /INFN, Bari /NASA, Goddard /Maryland U.; /more authors..

    2012-04-11T23:59:59.000Z

    The diffuse galactic {gamma}-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray Observatory indicated excess {gamma}-ray emission {ge}1 GeV relative to diffuse galactic {gamma}-ray emission models consistent with directly measured CR spectra (the so-called 'EGRET GeV excess'). The Large Area Telescope (LAT) instrument on the Fermi Gamma-Ray Space Telescope has measured the diffuse {gamma}-ray emission with improved sensitivity and resolution compared to EGRET. We report on LAT measurements for energies 100 MeV to 10 GeV and galactic latitudes 10{sup o} {le} |b| {le} 20{sup o}. The LAT spectrum for this region of the sky is well reproduced by a diffuse galactic {gamma}-ray emission model that is consistent with local CR spectra and inconsistent with the EGRET GeV excess.

  19. Is the northern high latitude land-based CO2 sink weakening?

    SciTech Connect (OSTI)

    Mcguire, David [University of Alaska; Kicklighter, David W. [Ecosystem Center, The; Gurney, Kevin R [Arizona State University; Burnside, Todd [University of Alaska, Fairbanks; Melillo, Jerry [Marine Biological Laboratory

    2011-01-01T23:59:59.000Z

    Studies indicate that, historically, terrestrial ecosystems of the northern high latitude region may have been responsible for up to 60% of the global net land-based sink for atmospheric CO2. However, these regions have recently experienced remarkable modification of the major driving forces of the carbon cycle, including surface air temperature warming that is significantly greater than the global average and associated increases in the frequency and severity of disturbances. Whether arctic tundra and boreal forest ecosystems will continue to sequester atmospheric CO2 in the face of these dramatic changes is unknown. Here we show the results of model simulations that estimate a 41 Tg C yr-1 sink in the boreal land regions from 1997 to 2006, which represents a 73% reduction in the strength of the sink estimated for previous decades in the late 20th Century. Our results suggest that CO2 uptake by the region in previous decades may not be as strong as previously estimated. The recent decline in sink strength is the combined result of 1) weakening sinks due to warming-induced increases in soil organic matter decomposition and 2) strengthening sources from pyrogenic CO2 emissions as a result of the substantial area of boreal forest burned in wildfires across the region in recent years. Such changes create positive feedbacks to the climate system that accelerate global warming, putting further pressure on emission reductions to achieve atmospheric stabilization targets.

  20. GTL-1 Irradiation Summary Report

    SciTech Connect (OSTI)

    D. M. Perez; G. S. Chang; N. E. Woolstenhulme; D. M. Wachs

    2012-01-01T23:59:59.000Z

    The primary objective of the Gas Test Loop (GTL-1) miniplate experiment is to confirm acceptable performance of high-density (i.e., 4.8 g-U/cm3) U3Si2/Al dispersion fuel plates clad in Al-6061 and irradiated under the relatively aggressive Booster Fast Flux Loop (BFFL) booster fuel conditions, namely a peak plate surface heat flux of 450 W/cm2. As secondary objectives, several design and fabrication variations were included in the test matrix that may have the potential to improve the high-heat flux, high-temperature performance of the base fuel plate design.1, 2 The following report summarizes the life of the GTL-1 experiment through end of irradiation, including as-run neutronic analysis, thermal analysis and hydraulic testing results.

  1. Overlay welding irradiated stainless steel

    SciTech Connect (OSTI)

    Kanne, W.R.; Chandler, G.T.; Nelson, D.Z.; Franco-Ferreira, E.A.

    1993-08-01T23:59:59.000Z

    An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to n,{alpha} reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods.

  2. Nuclear plant irradiated steel handbook

    SciTech Connect (OSTI)

    Oldfield, W.; Oldfield, F.M.; Lombrozo, P.M.; McConnell, P.

    1986-09-01T23:59:59.000Z

    This reference handbook presents selected information extracted from the EPRI reactor surveillance program database, which contains the results from surveillance program reports on 57 plants and 116 capsules. Tabulated data includes radiation induced temperature shifts, capsule irradiation conditions and statistical features of the Charpy V-notch curves. General information on the surveillance materials is provided and the Charpy V-notch energy results are presented graphically.

  3. RERTR-13 Irradiation Summary Report

    SciTech Connect (OSTI)

    D. M. Perez; M. A. Lillo; G. S. Chang; D. M. Wachs; G. A. Roth; N. E. Woolstenhulme

    2012-09-01T23:59:59.000Z

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-13 was designed to assess performance of different types of neutron absorbers that can be potentially used as burnable poisons in the low enriched uranium-molybdenum based dispersion and monolithic fuels.1 The following report summarizes the life of the RERTR-13 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

  4. Study of the interaction of solutes with ?5 (013) tilt grain boundaries in iron using density-functional theory

    SciTech Connect (OSTI)

    Jin, Hao; Militzer, Matthias [Centre for Metallurgical Process Engineering, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada); Elfimov, Ilya [Quantum Matter Institute, The University of British Columbia, Vancouver, British Columbia V6T 1Z4 (Canada)

    2014-03-07T23:59:59.000Z

    Substitutional alloying elements significantly affect the recrystallization and austenite-ferrite phase transformation rates in steels. The atomistic mechanisms of their interaction with the interfaces are still largely unexplored. Using density functional theory, we determine the segregation energies between commonly used alloying elements and the ?5 (013) tilt grain boundary in bcc iron. We find a strong solute-grain boundary interaction for Nb, Mo, and Ti that is consistent with experimental observations of the effects of these alloying elements on delaying recrystallization and the austenite-to-ferrite transformation in low-carbon steels. In addition, we compute the solute-solute interactions as a function of solute pair distance in the grain boundary, which suggest co-segregation for these large solutes at intermediate distances in striking contrast to the bulk.

  5. The sensitivity enhancement of tilted fibre Bragg grating sensors with polarization dependent resonant nano-scale coatings

    E-Print Network [OSTI]

    Bialiayeu, Aliaksandr

    2015-01-01T23:59:59.000Z

    Fibre Bragg grating sensors have emerged as a simple, inexpensive, accurate, sensitive and reliable platform, a viable alternative to the traditional bulkier optical sensor platforms. In this work we present an extensive theoretical analysis of the tilted fibre Bragg grating sensor (TFBG) with a particular focus on its polarization-dependent properties. We have developed a highly efficient computer model capable of providing the full characterization of the TFBG device in less then $3$~minutes for a given state of incident light polarization. As a result, the polarization-dependent spectral response, the field distribution at the sensor surface as well as the fine structure of particular resonances have become accessible for theoretical analysis. As a part of this computer model we have developed a blazingly fast full-vector complex mode solver, capable of handling cylindrical waveguides of an arbitrary complex refractive index profile. Along with the theoretical study we have investigated optical properties ...

  6. Crystallographically tilted and partially strain relaxed GaN grown on inclined (111) facets etched on Si(100) substrate

    SciTech Connect (OSTI)

    Ansah Antwi, K. K. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore); Soh, C. B. [Singapore Institute of Technology, 10 Dover Drive, Singapore 138683 (Singapore); Wee, Q. [Singapore-MIT Alliance, National University of Singapore, Singapore 117576 (Singapore); Tan, Rayson J. N.; Tan, H. R. [Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore); Yang, P. [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, 117603 Singapore (Singapore); Sun, L. F.; Shen, Z. X. [School of Physical and Mathematical Sciences, Nanyang Technological University, SPMS-03-01, 21 Nanyang Link (Singapore); Chua, S. J., E-mail: elecsj@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore); Singapore-MIT Alliance, National University of Singapore, Singapore 117576 (Singapore)

    2013-12-28T23:59:59.000Z

    High resolution X-ray diffractometry (HR-XRD), Photoluminescence, Raman spectroscopy, and Transmission electron microscope measurements are reported for GaN deposited on a conventional Si(111) substrate and on the (111) facets etched on a Si(100) substrate. HR-XRD reciprocal space mappings showed that the GaN(0002) plane is tilted by about 0.63°?±?0.02° away from the exposed Si(111) growth surface for GaN deposited on the patterned Si(100) substrate, while no observable tilt existed between the GaN(0002) and Si(111) planes for GaN deposited on the conventional Si(111) substrate. The ratio of integrated intensities of the yellow to near band edge (NBE) luminescence (I{sub YL}/I{sub NBE}) was determined to be about one order of magnitude lower in the case of GaN deposited on the patterned Si(100) substrate compared with GaN deposited on the conventional Si(111) substrate. The Raman E{sub 2}(high) optical phonon mode at 565.224?±?0.001?cm{sup ?1} with a narrow full width at half maximum of 1.526?±?0.002?cm{sup ?1} was measured, for GaN deposited on the patterned Si(100) indicating high material quality. GaN deposition within the trench etched on the Si(100) substrate occurred via diffusion and mass-transport limited mechanism. This resulted in a differential GaN layer thickness from the top (i.e., 1.8??m) of the trench to the bottom (i.e., 0.3??m) of the trench. Mixed-type dislocation constituted about 80% of the total dislocations in the GaN grown on the inclined Si(111) surface etched on Si(100)

  7. Cluster characters II: A multiplication formula Let C be a Hom-finite triangulated 2-CalabiYau category with a cluster tilting object. Under

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Cluster characters II: A multiplication formula Yann Palu Abstract Let C be a Hom categories of modules over a preprojective algebra of Dynkin type, we prove a multiplication formula for the cluster character associated with any cluster tilting object. This formula generalizes those obtained

  8. PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan and Ilya Tsvankin , Center for Wave Phenomena, Colorado School of Mines (CSM),

    E-Print Network [OSTI]

    PS-wave moveout inversion for tilted TI media: A physical-modeling study Pawan Dewangan and Ilya Tsvankin , Center for Wave Phenomena, Colorado School of Mines (CSM), Mike Batzle, Center for Rock Abuse, CSM, Kasper van Wijk, Physical Acoustics Laboratory, CSM, and Matt Haney, Center for Wave Phenomena

  9. Measurements Versus Predictions for the Static and Dynamic Characteristics of a Four-pad Rocker-pivot, Tilting-pad Journal Bearing

    E-Print Network [OSTI]

    Tschoepe, David 1987-

    2012-08-16T23:59:59.000Z

    Measured and predicted static and dynamic characteristics are provided for a four-pad, rocker-pivot, tilting-pad journal bearing in the load-on-pad and load-between-pad orientations. The bearing has the following characteristics: 4 pads, .57 pad...

  10. Measured and predicted rotordynamic coefficients and static performance of a rocker-pivot, tilt pad bearing in load-on-pad and load-between-pad configurations

    E-Print Network [OSTI]

    Carter, Clint Ryan

    2009-06-02T23:59:59.000Z

    This thesis presents the static and dynamic performance data for a 5 pad tilting pad bearing in both the load-on-pad (LOP) and the load-between-pad (LBP) configurations over a variety of different loads and speeds. The bearing tested was an Orion...

  11. Solar Schools Assessment and Implementation Project: Financing...

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

    the annual solar resource data for different latitudes. 5 To maximize the annual energy production at a location of 40 north latitude, the optimal tilt varies from 30...

  12. Proton Irradiation Study of GFR Candidate Ceramics

    SciTech Connect (OSTI)

    Jian Gan; Yong Yang; Clayton Dickson; Todd Allen

    2009-05-01T23:59:59.000Z

    This work investigated the microstructural response of ZrC, ZrN, TiN, and SiC irradiated with 2.6 MeV protons at 800ºC to a single dose in the range of 1.5 to 3.0 displacement per atom (dpa), depending on the material. The change of lattice constant evaluated using HOLZ patterns is not observed and is small when measured using XRD for the irradiated samples up to 1.5 dpa for 6H-SiC, and up to 3.0 dpa for ZrC and ZrN. In comparison to Kr ion irradiation at 800ºC to 10 dpa from the previous studies, the proton-irradiated ceramics at 3.0 dpa show less irradiation damage to the lattice structure. The irradiated ZrC exhibits faulted loops which are not observed in the Kr ion irradiated sample. The irradiated ZrN shows the least microstructural change from proton irradiation. The microstructure of 6H-SiC irradiated to 3.0 dpa consists of a black dot defect type at high density.

  13. Vertical profiles of radar reflectivity of convective cells in tropical and mid-latitude mesoscale convective systems

    E-Print Network [OSTI]

    Lutz, Kurt Reed

    1992-01-01T23:59:59.000Z

    meteorological phenomenon of particular interest to forecasters is the mesoscale convective system (MCS). Chappell (1986) defines an MCS as "any multicellular storm or group of interacting storms that suggests some organization in its forcing". An MCS...VERTICAL PROFILES OF RADAR REFLECTIVITY OF CONVECTIVE CELLS IN TROPICAL AND MID-LATITUDE MESOSCALE CONVECTIVE SYSTEMS A Thesis by KURT REED LUTZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

  14. An analysis of modified convective available potential energy and Richardson number in mid-latitude squall line environments

    E-Print Network [OSTI]

    Stricherz, James Nicholas

    1989-01-01T23:59:59.000Z

    modified convective available potential energy (MCAPE) and Richardson number (MRI) were computed for each upper air sounding in a synoptic ? scale data network. The resulting fields were contoured and compared to the development, growth and decay of mid... ? latitude squall lines in several cases studies. The results indicate that, though the squall lines remained in the vicinity of MCAPE maxima and MRI minima there was no quantitative association. The squall lines also appeared to avoid these regions...

  15. Realistic analytic model for the prompt and high latitude emission in GRBs

    E-Print Network [OSTI]

    F. Genet; J. Granot

    2009-07-15T23:59:59.000Z

    Most gamma-ray bursts (GRBs) observed by the Swift satellite show an early rapid decay phase (RDP) in their X-ray lightcurve, which is usually a smooth continuation of the prompt gamma-ray emission, strongly suggesting that it is its tail. However, the mechanism behind it is still not clear. The most popular model for this RDP is High Latitude Emission (HLE). While HLE is expected in many models for the prompt GRB emission, such as the popular internal shocks model, there are models in which it is not expected, such as sporadic magnetic reconnection events. Therefore, testing whether the RDP is consistent with HLE can help distinguish between different prompt emission models. We address this question by modeling the prompt emission as the sum of its individual pulses with their HLE tails. Analytic expressions for the observed flux density are obtained for power-law and Band function emission spectra. For internal shocks the observed instantaneous spectrum is very close to the emitted one, and should be well described by a Band function also during the RDP. Our model naturally produces, the observed spectral softening and steepening of the flux decay. The observed flux during the RDP is initially dominated by the tail of the last pulse, but the tails of one or more earlier pulses can become dominant later on. Moreover, modeling several overlapping pulses as a single wider pulse would over-predict the emission tail. Thus, one should be very careful when testing the predictions of HLE and do a combined temporal and spectral fit of the prompt GRB emission and the RDP.

  16. Irradiation Effects on Microstructure Change in Nanocrystalline...

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

    Effects on Microstructure Change in Nanocrystalline Ceria - Phase, lattice Stress, Grain Size and Boundaries. Irradiation Effects on Microstructure Change in Nanocrystalline Ceria...

  17. Enterprise Assessments, Oak Ridge National Laboratory Irradiated...

    Energy Savers [EERE]

    and Health Assessments conducted an independent assessment of the safety-significant ventilation systems at the Oak Ridge National Laboratory (ORNL) Irradiated Fuels...

  18. Irradiation Testing of Ultrasonic Transducers

    SciTech Connect (OSTI)

    Daw, Joshua; Tittmann, Bernhard; Reinhardt, Brian; Kohse, Gordon E.; Ramuhalli, Pradeep; Montgomery, Robert O.; Chien, Hual-Te; Villard, Jean-Francois; Palmer, Joe; Rempe, Joy

    2013-12-01T23:59:59.000Z

    Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. For this reason, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). The goal of this research is to characterize magnetostrictive and piezoelectric transducer survivability during irradiation, enabling the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). As such, this test will be an instrumented lead test and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.

  19. Sodium and potassium levels in the serum of acutely irradiated and non-irradiated rats

    E-Print Network [OSTI]

    Shepherd, David Preston

    1967-01-01T23:59:59.000Z

    SODIUM AND POTASSIUM LEVELS IN THE SERUM OF ACUTELY IRRADIATED AND NON-IRRADIATED RATS A Thesis By DAVID PRESTON SHEPHERD Submitted to the Graduate College of the Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1967 Major Subject: Zoology SODIUM AND POTASSIUM LEVELS IN THE SERUM OF ACUTELY IRRADIATED AND NON-IRRADIATED RATS A Thesis By DAVID PRESTON SHEPHERD Approved as to style and content by: (Chairman of Committee) (Head...

  20. Methane Fluxes Between Terrestrial Ecosystems and the Atmosphere at Northern High Latitudes During the Past Century: A retrospective analysis with a process-based biogeochemistry model

    E-Print Network [OSTI]

    Zhuang, Qianlai.

    We develop and use a new version of the Terrestrial Ecosystem Model (TEM) to study how rates of methane (CH4) emissions and consumption in high-latitude soils of the Northern Hemisphere have changed over the past century ...

  1. DIFFUSE GALACTIC LIGHT IN THE FIELD OF THE TRANSLUCENT HIGH GALACTIC LATITUDE CLOUD MBM32

    SciTech Connect (OSTI)

    Ienaka, N.; Kawara, K. [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan)] [Institute of Astronomy, University of Tokyo, 2-21-1 Osawa, Mitaka, Tokyo 181-0015 (Japan); Matsuoka, Y.; Oyabu, S. [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)] [Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Sameshima, H. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8501 (Japan)] [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8501 (Japan); Tsujimoto, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Peterson, B. A., E-mail: ienaka@ioa.s.u-tokyo.ac.jp [Research School of Astronomy and Astrophysics, The Australian National University, Weston Creek, ACT 2611 (Australia)

    2013-04-10T23:59:59.000Z

    We have conducted B-, g-, V-, and R-band imaging in a 45' Multiplication-Sign 40' field containing part of the high Galactic latitude translucent cloud MBM32, and correlated the intensity of diffuse optical light S{sub {nu}}({lambda}) with that of 100 {mu}m emission S{sub {nu}}(100 {mu}m). A {chi}{sup 2} minimum analysis is applied to fit a linear function to the measured correlation and derive the slope parameter b({lambda}) = {Delta}S{sub {nu}}({lambda})/{Delta}S{sub {nu}}(100 {mu}m) of the best-fit linear function. Compiling a sample by combining our b({lambda}) and published ones, we show that the b({lambda}) strength varies from cloud to cloud by a factor of four. Finding that b({lambda}) decreases as S{sub {nu}}(100 {mu}m) increases in the sample, we suggest that a nonlinear correlation including a quadratic term of S{sub {nu}}(100 {mu}m){sup 2} should be fitted to the measured correlation. The variation of optical depth, which is A{sub V} = 0.16-2.0 in the sample, can change b({lambda}) by a factor of 2-3. There would be some contribution to the large b({lambda}) variation from the forward-scattering characteristic of dust grains which is coupled to the non-isotropic interstellar radiation field (ISRF). Models of the scattering of diffuse Galactic light (DGL) underestimate the b({lambda}) values by a factor of two. This could be reconciled by deficiency in UV photons in the ISRF or by a moderate increase in dust albedo. Our b({lambda}) spectrum favors a contribution from extended red emission (ERE) to the diffuse optical light; b({lambda}) rises from B to V faster than the models, seems to peak around 6000 A and decreases toward long wavelengths. Such a characteristic is expected from the models in which the DGL is combined with ERE.

  2. AGC-1 Irradiation Experiment Test Plan

    SciTech Connect (OSTI)

    R. L. Bratton

    2006-05-01T23:59:59.000Z

    The Advanced Graphite Capsule (AGC) irradiation test program supports the acquisition of irradiated graphite performance data to assist in the selection of the technology to be used for the VHTR. Six irradiations are planned to investigate compressive creep in graphite subjected to a neutron field and obtain irradiated mechanical properties of vibrationally molded, extruded, and iso-molded graphites for comparison. The experiments will be conducted at three temperatures: 600, 900, and 1200°C. At each temperature, two different capsules will be irradiated to different fluence levels, the first from 0.5 to 4 dpa and the second from 4 to 7 dpa. AGC-1 is the first of the six capsules designed for ATR and will focus on the prismatic fluence range.

  3. Strain Accommodation By Facile WO6 Octahedral Distortion and Tilting During WO3 Heteroepitaxy on SrTiO3(001)

    SciTech Connect (OSTI)

    Du, Yingge; Gu, Meng; Varga, Tamas; Wang, Chong M.; Bowden, Mark E.; Chambers, Scott A.

    2014-08-27T23:59:59.000Z

    In this paper, we show that compared to other BO6 octahedra in ABO3 structured perovskite oxides, the WO6 octahedra in tungsten trioxide (WO3) can withstand a much larger degree of distortion and tilting to accommodate interfacial strain, which in turn strongly impact the nucleation, structure, and defect formation during the epitaxial growth of WO3 on SrTiO3(001). A meta-stable tetragonal phase can be stabilized by epitaxy and a thickness dependent phase transition (tetragonal to monoclinic) is observed. In contrast to misfit dislocations to accommodate the interfacial stain, the facial WO6 octahedral distortion and tilting give rise to three types of planar defects that affect more than 15 monolayers from the interface. These atomically resolved, unusual interfacial defects may significantly alter the electronic, electrochromic, and mechanical properties of the epitaxial films.

  4. Magnetoresistivity and acoustoelectronic effects in a tilted magnetic field in p-Si/SiGe/Si structures with an anisotropic g factor

    SciTech Connect (OSTI)

    Drichko, I. L., E-mail: Irina.L.Drichko@mail.ioffe.ru; Smirnov, I. Yu. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory (United States); Mironov, O. A. [University of Warwick Science Park, Warwick SEMINANO R and D Centre (United Kingdom); Leadley, D. R. [University of Warwick Science Park, Department of Physics (United Kingdom)

    2010-09-15T23:59:59.000Z

    Magnetoresistivity {rho}{sub xx} and {rho}{sub xy} and the acoustoelectronic effects are measured in p-Si/SiGe/Si with an impurity concentration p = 1.99 x 10{sup 11} cm{sup -2} in the temperature range 0.3-2.0 K and an tilted magnetic field up to 18 T. The dependence of the effective g factor on the angle of magnetic field tilt {theta} to the normal to the plane of a two-dimensional p-Si/SiGe/Si channel is determined. A first-order ferromagnet-paramagnet phase transition is observed in the magnetic fields corresponding to a filling factor {nu} = 2 at {theta} {approx} 59{sup o}-60{sup o}.

  5. Magnetoresistivity in a tilted magnetic field in p-Si/SiGe/Si heterostructures with an anisotropic g-factor. Part II

    SciTech Connect (OSTI)

    Drichko, I. L.; Smirnov, I. Yu., E-mail: ivan.smirnov@mail.ioffe.ru [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory (United States); Mironov, O. A. [University of Warwick Science Park, Warwick SEMINANO R and D Centre (United Kingdom); Leadley, D. R. [University of Warwick, Department of Physics (United Kingdom)

    2012-09-15T23:59:59.000Z

    The magnetoresistance components {rho}xx and {rho}xy are measured in two p-Si/SiGe/Si quantum wells that have an anisotropic g-factor in a tilted magnetic field as a function of the temperature, field, and tilt angle. Activation energy measurements demonstrate the existence of a ferromagnetic-paramagnetic (F-P) transition for the sample with the hole density p = 2 Multiplication-Sign 10{sup 11} cm{sup -2}. This transition is due to the crossing of the 0{up_arrow} and 1{down_arrow} Landau levels. However, in another sample with p = 7.2 Multiplication-Sign 10{sup 10} cm{sup -2}, the 0{up_arrow} and 1{down_arrow} Landau levels coincide for angles {theta} = 0-70 Degree-Sign . Only for {theta} > 70 Degree-Sign do the levels start to diverge which, in turn, results in the energy gap opening.

  6. Magnetization measurements and XMCD studies on ion irradiated...

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

    measurements and XMCD studies on ion irradiated iron oxide and core-shell ironiron-oxide nanomaterials. Magnetization measurements and XMCD studies on ion irradiated iron oxide...

  7. Direct Observation of Ion-irradiation-induced Chemical Mixing...

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

    the ion-irradiation induced elemental mixing and dissolution of 25–50 nm titanium oxycarbonitrides in a nanostructured ferritic alloy irradiated at 173 K. The...

  8. Automatic recovery of missing amplitudes and phases in tilt-limited electron crystallography of two-dimensional crystals

    SciTech Connect (OSTI)

    Gipson, Bryant R.; Stahlberg, Henning [Center for Cellular Imaging and Nano Analytics (C-CINA), Biozentrum, University Basel, WRO-1058 Mattenstrasse 26, CH-4058 Basel (Switzerland); Masiel, Daniel J.; Browning, Nigel D. [Department of Chemical Engineering and Materials Sciences, University of California at Davis, Davis, California 95616 (United States); Spence, John [Department of Physics, Arizona State University, Tempe, Arizona 85287 (United States); Mitsuoka, Kaoru [Biomedicinal Information Research Center (BIRC), National Institute of Advanced Industrial Science and Technology (AIST), 2-3-26, Aomi, Koto-ku, Tokyo 135-0064 (Japan)

    2011-07-15T23:59:59.000Z

    Electron crystallography of 2D protein crystals provides a powerful tool for the determination of membrane protein structure. In this method, data is acquired in the Fourier domain as randomly sampled, uncoupled, amplitudes and phases. Due to physical constraints on specimen tilting, those Fourier data show a vast un-sampled ''missing cone'' of information, producing resolution loss in the direction perpendicular to the membrane plane. Based on the flexible language of projection onto sets, we provide a full solution for these problems with a projective constraint optimization algorithm that, for sufficiently oversampled data, produces complete recovery of unmeasured data in the missing cone. We apply this method to an experimental data set of Bacteriorhodopsin and show that, in addition to producing superior results compared to traditional reconstruction methods, full, reproducible, recovery of the missing cone from noisy data is possible. Finally, we present an automatic implementation of the refinement routine as open source, freely distributed, software that will be included in our 2dx software package.

  9. Investigation of Copper Segregation to the S5(310)/[001] Symmetric Tilt Grain Boundary (STGB) in Aluminum

    SciTech Connect (OSTI)

    Plitzko, J.M.; Campbell, G.H.; King, W.E.; Foiles, S.M.

    1999-11-15T23:59:59.000Z

    The {Sigma}5 (310)/[001] symmetric tilt grain boundary (STGB) in the face centered cubic (FCC) metal aluminum with 1at% copper has been studied. The model grain boundary has been fabricated by ultra-high vacuum diffusion bonding of alloy single crystals. The segregation of the copper has been encouraged by annealing the sample after bonding at 200 C. TEM samples of this FCC-material were prepared with a new low voltage ion mill under very low angles. The atomic structure of the {Sigma}5 (310)/[001] STGB for this system was modeled with electronic structure calculations. These theoretical calculations of this interface structure indicate that the Cu atoms segregate to distinct sites at the interface. High resolution electron microscopy (HRTEM) and analytical electron microscopy including electron energy spectroscopic imaging and X-ray energy dispersive spectrometry have been used to explore the segregation to the grain boundary. The HRTEM images and the analytical measurements were performed using different kinds of microscopes, including a Philips CM300 FEG equipped with an imaging energy filter. The amount of the segregated species at the interface was quantified in a preliminary way. To determine the atomic positions of the segregated atoms at the interface, HRTEM coupled with image simulation and a first attempt of a holographic reconstruction from a through-focal series have been used.

  10. AGC-1 Post Irradiation Examination Status

    SciTech Connect (OSTI)

    David Swank

    2011-09-01T23:59:59.000Z

    The Next Generation Nuclear Plant (NGNP) Graphite R&D program is currently measuring irradiated material property changes in several grades of nuclear graphite for predicting their behavior and operating performance within the core of new Very High Temperature Reactor (VHTR) designs. The Advanced Graphite Creep (AGC) experiment consisting of six irradiation capsules will generate this irradiated graphite performance data for NGNP reactor operating conditions. All six AGC capsules in the experiment will be irradiated in the Advanced Test Reactor (ATR), disassembled in the Hot Fuel Examination Facility (HFEF), and examined at the INL Research Center (IRC) or Oak Ridge National Laboratory (ORNL). This is the first in a series of status reports on the progress of the AGC experiment. As the first capsule, AGC1 was irradiated from September 2009 to January 2011 to a maximum dose level of 6-7 dpa. The capsule was removed from ATR and transferred to the HFEF in April 2011 where the capsule was disassembled and test specimens extracted from the capsules. The first irradiated samples from AGC1 were shipped to the IRC in July 2011and initial post irradiation examination (PIE) activities were begun on the first 37 samples received. PIE activities continue for the remainder of the AGC1 specimen as they are received at the IRC.

  11. The effects of coronal mass ejection on galactic cosmic rays in the high latitude heliosphere: Observations from Ulysses` first orbit

    SciTech Connect (OSTI)

    Bothmer, V.; Heber, B.; Kunow, H.; Mueller-Mellin, R.; Wibberenz, G. [Univ. of Kiel (Germany). Institut fuer Kernphysik; Gosling, J.T. [Los Alamos National Lab., NM (United States); Balogh, A. [Imperial College, London (United Kingdom). Blackett Lab.; Raviart, A. [CEA, Gif-sur-Yvette (France). Service d`Astrophysique; Paizis, C. [Univ. di Milano (Italy). Istituto di Fisica Cosmica CNR

    1997-10-01T23:59:59.000Z

    During its first solar orbit the Ulysses spacecraft detected several coronal mass ejections (CMEs) at high heliographic latitudes. The authors present first observations on the effects of these high latitude CMEs on galactic cosmic rays (GCRs) using measurements from the Kiel Electron Telescope (KET) which is part of the Cosmic Ray and Solar Particle Investigation (COSPIN) experiment, the Los Alamos SWOOPS (Solar Wind Observations Over the Poles of the Sun) experiment and the magnetic field experiments. They find the passage of these CMEs over the spacecraft to be associated with short term decreases of GCR intensities The relatively weak shocks in these events, driven by the CMEs` over-expansion, had no strong influence on the GCRs. The intensity minimums of GCRs occurred on closed magnetic field lines inside the CMEs themselves as indicated by bidirectional fluxes of suprathermal electrons. Short episodes of intensity increases of GCRs inside CMEs at times when the bidirectional fluxes of suprathermal electrons disappeared, can be interpreted as evidence that GCRs can easily access the interior of those CMEs in which open magnetic field lines are embedded.

  12. RERTR-12 Insertion 2 Irradiation Summary Report

    SciTech Connect (OSTI)

    D. M. Perez; G. S. Chang; D. M. Wachs; G. A. Roth; N. E. Woolstenhulme

    2012-09-01T23:59:59.000Z

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-12 was designed to provide comprehensive information on the performance of uranium-molybdenum (U-Mo) based monolithic fuels for research reactor applications.1 RERTR-12 insertion 2 includes the capsules irradiated during the last three irradiation cycles. These capsules include Z, Y1, Y2 and Y3 type capsules. The following report summarizes the life of the RERTR-12 insertion 2 experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

  13. Measuring Degradation Rates Without Irradiance Data

    SciTech Connect (OSTI)

    Pulver, S.; Cormode, D.; Cronin, A.; Jordan, D.; Kurtz, S.; Smith, R.

    2011-02-01T23:59:59.000Z

    A method to report PV system degradation rates without using irradiance data is demonstrated. First, a set of relative degradation rates are determined by comparing daily AC final yields from a group of PV systems relative to the average final yield of all the PV systems. Then, the difference between relative and absolute degradation rates is found from a statistical analysis. This approach is verified by comparing to methods that utilize irradiance data. This approach is significant because PV systems are often deployed without irradiance sensors, so the analysis method described here may enable measurements of degradation using data that were previously thought to be unsuitable for degradation studies.

  14. A 24-h forecast of solar irradiance using artificial neural network: Application for performance prediction of a grid-connected PV plant at Trieste, Italy

    SciTech Connect (OSTI)

    Mellit, Adel [Department of Electronics, Faculty of Sciences and Technology, LAMEL, Jijel University, Ouled-aissa, P.O. Box 98, Jijel 18000 (Algeria); Pavan, Alessandro Massi [Department of Materials and Natural Resources, University of Trieste Via A. Valerio, 2 - 34127 Trieste (Italy)

    2010-05-15T23:59:59.000Z

    Forecasting of solar irradiance is in general significant for planning the operations of power plants which convert renewable energies into electricity. In particular, the possibility to predict the solar irradiance (up to 24 h or even more) can became - with reference to the Grid Connected Photovoltaic Plants (GCPV) - fundamental in making power dispatching plans and - with reference to stand alone and hybrid systems - also a useful reference for improving the control algorithms of charge controllers. In this paper, a practical method for solar irradiance forecast using artificial neural network (ANN) is presented. The proposed Multilayer Perceptron MLP-model makes it possible to forecast the solar irradiance on a base of 24 h using the present values of the mean daily solar irradiance and air temperature. An experimental database of solar irradiance and air temperature data (from July 1st 2008 to May 23rd 2009 and from November 23rd 2009 to January 24th 2010) has been used. The database has been collected in Trieste (latitude 45 40'N, longitude 13 46'E), Italy. In order to check the generalization capability of the MLP-forecaster, a K-fold cross-validation was carried out. The results indicate that the proposed model performs well, while the correlation coefficient is in the range 98-99% for sunny days and 94-96% for cloudy days. As an application, the comparison between the forecasted one and the energy produced by the GCPV plant installed on the rooftop of the municipality of Trieste shows the goodness of the proposed model. (author)

  15. Supine Craniospinal Irradiation Using Intrafractional Junction Shifts and Field-in-Field Dose Shaping: Early Experience at Methodist Hospital

    SciTech Connect (OSTI)

    South, Michael C. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States)], E-mail: msouth@tmhs.org; Chiu, J. Kam; Teh, Bin S. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States); Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Bloch, Charles [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Schroeder, Thomas M. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States); Department of Radiation Oncology, University of New Mexico, Albuquerque, NM (United States); Paulino, Arnold C. [Department of Radiation Oncology, Methodist Hospital, Houston, TX (United States); Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Houston, TX (United States)

    2008-06-01T23:59:59.000Z

    Purpose: To describe our preliminary experience with supine craniospinal irradiation. The advantages of the supine position for craniospinal irradiation include patient comfort, easier access to maintain an airway for anesthesia, and reduced variability of the head tilt in the face mask. Methods and Materials: The cranial fields were treated with near lateral fields and a table angle to match their divergence to the superior edge of the spinal field. The collimator was rotated to match the divergence from the superior spinal field. The spinal fields were treated using a source to surface distance (SSD) technique with the couch top at 100 cm. When a second spinal field was required, the table and collimator were rotated 90{sup o} to allow for the use of the multileaf collimator and so the gantry could be rotated to match the divergence of the superior spinal field. The multileaf collimator was used for daily dynamic featherings and field-in-field dose control. Results: With a median follow-up of 20.2 months, five documented failures and no cases of radiation myelitis occurred in 23 consecutive patients. No failures occurred in the junctions of the spine-spine or brain-spine fields. Two failures occurred in the primary site alone, two in the spinal axis alone, and one primary site failure plus distant metastasis. The median time to recurrence was 17 months. Conclusion: The results of our study have shown that supine approach for delivering craniospinal irradiation is not associated with increased relapses at the field junctions. To date, no cases of radiation myelitis have developed.

  16. Selective irradiation of the vascular endothelium

    E-Print Network [OSTI]

    Schuller, Bradley W

    2007-01-01T23:59:59.000Z

    We developed a unique methodology to selectively irradiate the vascular endothelium in vivo to better understand the role of vascular damage in causing normal tissue radiation side-effects.The relationship between vascular ...

  17. Introduction The bay scallop, Argopecten irradi-

    E-Print Network [OSTI]

    71(3) 17 Introduction The bay scallop, Argopecten irradi- ans amplicostatus, has been present (Garcia-Cubas, 1968). Historical Uses Mollusks were used by the pre-Co- lumbian cultures in Mexico as food

  18. Neutron Irradiation Measurement for Superconducting Magnet

    E-Print Network [OSTI]

    McDonald, Kirk

    close to reactor core · Sample cool down by He gas loop: 10K ­ 20K · Fast neutron flux (En>0.1MeV): 1.4x. Materials, 49, p161 (1973&74) Reactor n on Al Reactor n on Cu fluence up to 2*1022 n/m2 (En>0.1MeV) RRR Irradiation at KUR · Kyoto Univ. Research Reactor Institute · MW max. thermal power · Irradiation cryostat

  19. Comparison of Deuterium Retention for Ion-irradiated and Neutron-irradiated Tungsten

    SciTech Connect (OSTI)

    Yasuhisa Oya; Masashi Shimada; Makoto Kobayashi; Takuji Oda; Masanori Hara; Hideo Watanabe; Yuji Hatano; Pattrick Calderoni; Kenji Okuno

    2011-12-01T23:59:59.000Z

    The behavior of D retention for Fe{sup 2+}-irradiated tungsten with a damage of 0.025-3 dpa was compared with that for neutron-irradiated tungsten with 0.025 dpa. The D{sub 2} thermal desorption spectroscopy (TDS) spectra for Fe{sup 2+}-irradiated tungsten consisted of two desorption stages at 450 and 550 K, while that for neutron-irradiated tungsten was composed of three stages and an addition desorption stage was found at 750 K. The desorption rate of the major desorption stage at 550K increased as the displacement damage increased due to Fe{sup 2+} irradiation increasing. In addition, the first desorption stage at 450K was found only for damaged samples. Therefore, the second stage would be based on intrinsic defects or vacancy produced by Fe{sup 2+} irradiation, and the first stage should be the accumulation of D in mono-vacancy and the activation energy would be relatively reduced, where the dislocation loop and vacancy is produced. The third one was found only for neutron irradiation, showing the D trapping by a void or vacancy cluster, and the diffusion effect is also contributed to by the high full-width at half-maximum of the TDS spectrum. Therefore, it can be said that the D{sub 2} TDS spectra for Fe{sup 2+}-irradiated tungsten cannot represent that for the neutron-irradiated one, indicating that the deuterium trapping and desorption mechanism for neutron-irradiated tungsten is different from that for the ion-irradiated one.

  20. Major shifts in calcareous phytoplankton assemblages through the Eocene-Oligocene transition of Tanzania and their implications for low-latitude primary production

    E-Print Network [OSTI]

    Jones, Tom Dunkley; Bown, Paul R.; Pearson, Paul N.; Wade, Bridget S.; Coxall, Helen K.; Lear, Caroline H.

    Major shifts in calcareous phytoplankton assemblages through the Eocene-Oligocene transition of Tanzania and their implications for low-latitude primary production Tom Dunkley Jones, 1 Paul R. Bown, 2 Paul N. Pearson, 3 Bridget S. Wade, 4 Helen K... carbonate primary production at the onset of global cooling, and (3) a significant increase in nutrient availability in the low-latitude surface ocean through the EOT. Citation: Dunkley Jones, T., P. R. Bown, P. N. Pearson, B. S. Wade, H. K. Coxall, and C. H...

  1. The effects of continuous prenatal and postnatal low dose gamma irradiation on the hemopoietic system of immature Spanish goats

    E-Print Network [OSTI]

    DeShaw, James Richard

    1967-01-01T23:59:59.000Z

    Blood Cell Counts (RBC) 28 Irradiation period Post-irradiation period Hematocrit (Ht) 28 31 Irradiation period Post-irradiation period 34 38 Hemoglobin (Hg) 40 Irradiation period Post-irradiation period 40 43 Mean Corpuscular Volume (MCV...) Irradiation period Post-irradiation period 44 47 TABLE OF CONTENTS (Continued) Chapter Page Mean Corpuscular Hemoglobin (MCH) Irradiation period Post-irradiation period 4B 51 White Blood Cells (WBC) 53 Irradiation period post-irradiation period 53...

  2. Spread-F during the magnetic storm of 22 January 2004 at low latitudes: Effect of IMF-Bz in relation to local

    E-Print Network [OSTI]

    Padmanabhan, Janardhan

    measurements at an electrojet station Thumba. This phenomenon is found to occur during geomagnetic quiet of the orthogonal horizontal electric field and the geomagnetic field gives rise to several distinct features Electrojet (EEJ), a band of intense daytime eastward current in the ionosphere (100 km) within ± 3 latitudes

  3. Neogene Low-latitude Seasonal Environmental Variations: Stable Isotopic and Trace Elemental Records in Mollusks from the Florida Platform and the Central American Isthmus

    E-Print Network [OSTI]

    Tao, Kai

    2012-10-19T23:59:59.000Z

    This Ph.D. dissertation integrates stable isotope and trace element geochemistry in modern and fossil gastropod shells to study low-latitude marine paleoenvironments. First, stable isotopes (delta18O and delta13C) and Sr/Ca ratios are used...

  4. Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    SciTech Connect (OSTI)

    Wullschleger, Stan [ORNL] [ORNL

    2012-03-22T23:59:59.000Z

    Stan Wullschleger of Oak Ridge National Laboratory on "Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems" on March 22, 2012 at the 7th Annual Genomics of Energy & Environment Meeting in Walnut Creek, California.

  5. Northern mid-latitude glaciation in the Late Amazonian period of Mars: Criteria for the recognition of debris-covered glacier and valley glacier landsystem deposits

    E-Print Network [OSTI]

    Marchant, David R.

    in talus pile pore space caused lubrication and flow during an earlier climatic regime. A number of factors have remained uncertain, however, including the detailed structure and texture of LDA analogs, to assess the characteristics of LDA/LVF in the northern mid-latitudes of Mars. We find evidence

  6. Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems (JGI Seventh Annual User Meeting 2012: Genomics of Energy and Environment)

    ScienceCinema (OSTI)

    Wullschleger, Stan [ORNL

    2013-01-22T23:59:59.000Z

    Stan Wullschleger of Oak Ridge National Laboratory on "Omics in the Arctic: Genome-enabled Contributions to Carbon Cycle Research in High-Latitude Ecosystems" on March 22, 2012 at the 7th Annual Genomics of Energy & Environment Meeting in Walnut Creek, California.

  7. Heavy ion irradiation of crystalline water ice

    E-Print Network [OSTI]

    Dartois, E; Boduch, P; Brunetto, R; Chabot, M; Domaracka, A; Ding, J J; Kamalou, O; Lv, X Y; Rothard, H; da Silveira, E F; Thomas, J C

    2015-01-01T23:59:59.000Z

    Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic ...

  8. Laboratory for Characterization of Irradiated Graphite

    SciTech Connect (OSTI)

    Karen A. Moore

    2010-03-01T23:59:59.000Z

    The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center (IRC). The CCL was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite and ceramic composite research and development activities. The research is in support of the Advanced Graphite Creep (AGC) experiment — a major material irradiation experiment within the NGNP Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials.

  9. Irradiation effects on borosilicate waste glasses

    SciTech Connect (OSTI)

    Roberts, F.P.

    1980-06-01T23:59:59.000Z

    The effects of alpha decay on five borosilicate glasses containing simulated nuclear high-level waste oxides were studied. Irradiations carried out at room temperature were achieved by incorporating 1 to 8 wt % /sup 244/Cm/sub 2/O/sub 3/ in the glasses. Density changes and stored-energy build-up saturated at doses less than 2 x 10/sup 21/ alpha decays/kg. Damage manifested by stored energy was completely annealed at 633/sup 0/K. Positive and negative density changes were observed which never exceeded 1%. Irradiation had very little effect on mechanical strength or on chemical durability as measured by aqueous leach rates. Also, no effects were observed on the microstructure for vitreous waste glasses, although radiation-induced microcracking could be achieved on specimens that had been devitrified prior to irradiation.

  10. Horizontal modular dry irradiated fuel storage system

    DOE Patents [OSTI]

    Fischer, Larry E. (Los Gatos, CA); McInnes, Ian D. (San Jose, CA); Massey, John V. (San Jose, CA)

    1988-01-01T23:59:59.000Z

    A horizontal, modular, dry, irradiated fuel storage system (10) includes a thin-walled canister (12) for containing irradiated fuel assemblies (20), which canister (12) can be positioned in a transfer cask (14) and transported in a horizontal manner from a fuel storage pool (18), to an intermediate-term storage facility. The storage system (10) includes a plurality of dry storage modules (26) which accept the canister (12) from the transfer cask (14) and provide for appropriate shielding about the canister (12). Each module (26) also provides for air cooling of the canister (12) to remove the decay heat of the irradiated fuel assemblies (20). The modules (26) can be interlocked so that each module (26) gains additional shielding from the next adjacent module (26). Hydraulic rams (30) are provided for inserting and removing the canisters (12) from the modules (26).

  11. Testing three 90Whr Dell Batteries for Latitude E6410 I have been able, for complicated reasons, to test three batteries sold as 9cell 90Whr batteries for

    E-Print Network [OSTI]

    Sloman, Aaron

    Testing three 90Whr Dell Batteries for Latitude E6410 I have been able, for complicated reasons, to test three batteries sold as 9cell 90Whr batteries for the Dell Latitude E6410 computer, one made battery was fully charged then allowed to discharge while the laptop was on, and not doing very much

  12. Response of atmospheric ground level temperatures to changes in the total solar irradiance

    E-Print Network [OSTI]

    Erlykin, Anatoly

    2015-01-01T23:59:59.000Z

    The attribution of part of global warming to changes in the total solar irradiance (TSI) is an important topic which is not, yet, fully understood. Here, we examine the TSI induced temperature (T) changes on a variety of time scales, from one day to centuries and beyond, using a variety of assumptions. Also considered is the latitude variation of the T-TSI correlations, where it appears that over most of the globe there is a small increase in the sensitivity of temperature to TSI in time. It is found that the mean global sensitivity (alpha)measured in K(Wm-2)-1 varies from about 0.003 for 1 day, via 0.05 for 11-years to about 0.2 for decades to centuries. We conclude that mean global temperature changes related to TSI are not significant from 1975 onwards. Before 1975, when anthropogenic gases were less important, many of the temperature changes can be attributed to TSI variations. Over much longer periods of time, from Kyear to Myear, the TSI changes are more efficient still, the sensitivity alpha increasing...

  13. Heavy-Section Steel Irradiation Program

    SciTech Connect (OSTI)

    Rosseel, T.M.

    2000-04-01T23:59:59.000Z

    Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents that have the potential for major contamination release. Because the RPV is the only key safety-related component of the plant for which a redundant backup system does not exist, it is imperative to fully understand the degree of irradiation-induced degradation of the RPV's fracture resistance that occurs during service. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established.

  14. Effects of neutron flux and irradiation temperature on irradiation embrittlement of A533B steels

    SciTech Connect (OSTI)

    Suzuki, Masahide; Onizawa, Kunio; Kizaki, Minoru [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1996-12-31T23:59:59.000Z

    Irradiation embrittlement of A533B steels with low copper contents were investigated from the point of dose rate and irradiation temperature effects. Change of neutron flux in the range from {minus}10{sup 12} to {minus}10{sup 13} n/cm{sup 2}/s (E > 1 MeV) did not have a significant effect on the embrittlement. Irradiation temperature change of 1 C resulted in the transition temperature shift ({Delta}T{sub 41J}) of about 1 C and yield stress change ({Delta}{sigma}{sub y}) of about 0.8 MPa. Factors that might affect the embrittlement of low copper steels are also discussed.

  15. Understanding the Irradiation Behavior of Zirconium Carbide

    SciTech Connect (OSTI)

    Motta, Arthur; Sridharan, Kumar; Morgan, Dane; Szlufarska, Izabela

    2013-10-11T23:59:59.000Z

    Zirconium carbide (ZrC) is being considered for utilization in high-temperature gas-cooled reactor fuels in deep-burn TRISO fuel. Zirconium carbide possesses a cubic B1-type crystal structure with a high melting point, exceptional hardness, and good thermal and electrical conductivities. The use of ZrC as part of the TRISO fuel requires a thorough understanding of its irradiation response. However, the radiation effects on ZrC are still poorly understood. The majority of the existing research is focused on the radiation damage phenomena at higher temperatures (>450{degree}C) where many fundamental aspects of defect production and kinetics cannot be easily distinguished. Little is known about basic defect formation, clustering, and evolution of ZrC under irradiation, although some atomistic simulation and phenomenological studies have been performed. Such detailed information is needed to construct a model describing the microstructural evolution in fast-neutron irradiated materials that will be of great technological importance for the development of ZrC- based fuel. The goal of the proposed project is to gain fundamental understanding of the radiation-induced defect formation in zirconium carbide and irradiation response (ZrC) by using a combination of state-of-the-art experimental methods and atomistic modeling. This project will combine (1) in situ ion irradiation at a specialized facility at a national laboratory, (2) controlled temperature proton irradiation on bulk samples, and (3) atomistic modeling to gain a fundamental understanding of defect formation in ZrC. The proposed project will cover the irradiation temperatures from cryogenic temperature to as high as 800{degree}C, and dose ranges from 0.1 to 100 dpa. The examination of this wide range of temperatures and doses allows us to obtain an experimental data set that can be effectively used to exercise and benchmark the computer calculations of defect properties. Combining the examination of radiation-induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.

  16. A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego

    SciTech Connect (OSTI)

    Moy, C M; Dunbar, R B; Guilderson, T P; Waldmann, N; Mucciarone, D A; Recasens, C; Austin, J A; Anselmetti, F S

    2010-11-19T23:59:59.000Z

    Situated at the southern margin of the hemispheric westerly wind belt and immediately north of the Antarctic Polar Frontal zone, Tierra del Fuego is well-positioned to monitor coupled changes in the ocean-atmosphere system of the high southern latitudes. Here we describe a Holocene paleoclimate record from sediment cores obtained from Lago Fagnano, a large lake in southern Tierra del Fuego at 55{sup o}S, to investigate past changes in climate related to these two important features of the global climate system. We use an AMS radiocarbon chronology for the last 8,000 years based on pollen concentrates, thereby avoiding contamination from bedrock-derived lignite. Our chronology is consistent with a tephrochronologic age date for deposits from the middle Holocene Volcan Hudson eruption. Combining bulk organic isotopic ({delta}{sup 13}C and {delta}{sup 15}N) and elemental (C and N) parameters with physical sediment properties allow us to better understand sediment provenance and transport mechanisms and to interpret Holocene climate and tectonic change during the last 8,000 years. Co-variability and long-term trends in C/N ratio, carbon accumulation rate, and magnetic susceptibility reflect an overall Holocene increase in the delivery of terrestrial organic and lithogenic material to the deep eastern basin. We attribute this variability to westerly wind-derived precipitation. Increased wind strength and precipitation in the late Holocene drives the Nothofagus forest eastward and enhances run-off and terrigenous inputs to the lake. Superimposed on the long-term trend are a series of abrupt 9 negative departures in C/N ratio, which constrain the presence of seismically-driven mass flow events in the record. We identify an increase in bulk {delta}{sup 13}C between 7,000 and 5,000 cal yr BP that we attribute to enhanced aquatic productivity driven by warmer summer temperatures. The Lago Fagnano {delta}{sup 13}C record shows similarities with Holocene records of sea surface temperature from the mid-latitude Chilean continental shelf and Antarctic air temperatures from the Taylor Dome ice core record in East Antarctica. Mid-Holocene warming occurred simultaneously across the Antarctic Frontal Zone, and in particular, in locations currently influenced by the Antarctic Circumpolar Current.

  17. Implementation Plan for the Irradiated Materials Characterization Laboratory (IMCL)

    SciTech Connect (OSTI)

    Not Listed

    2013-04-01T23:59:59.000Z

    This document contains details regarding the planned implementation of the Irradiated Materials Characterization Laboratory at the INL.

  18. The Sun and Climate Solar Irradiance

    E-Print Network [OSTI]

    Walter, Frederick M.

    The Sun and Climate #12;Solar Irradiance The Solar Constant f = 1.4 x 106 erg/cm2/s. Over is higher when the Sun is more magnetically active. ·The Sun was magnetically active, and the climate the Sun Drive Climate? #12;The Temperature's Rising #12;Sunspots and CO2 What is Cause and What is Effect

  19. Low energy electron irradiation of an apple 

    E-Print Network [OSTI]

    Brescia, Giovanni Batista

    2002-01-01T23:59:59.000Z

    is the need to achieve a uniform dose over the entire surface of convoluted shapes. The main goal of this research was to calculate the dose distribution produced by low energy electron irradiation of a typical complex shape, an apple, using Monte Carlo...

  20. Radiation damage in neutron irradiated boron carbide

    SciTech Connect (OSTI)

    Shcherbak, V.I.; Bykov, V.N.; Rudenko, V.A.; Tarasikov, V.P.

    1986-09-01T23:59:59.000Z

    In view of the fact that there is no information on the microstructure of specimens of boron carbide containing up to 60% B 10 isotope and irradiated at a temperature of 350-370 C, the authors undertook a detailed study of the radiation-induced defects in such material. The microstructure of unexposed boron carbide is characterized by the presence of pores originating during the technological process, dislocations, and twins. Irradiation of B/sub 4/C leads to the formation of defects measuring 3-20 nm and exhibiting a contrast that is characteristic of dislocation loops or two-dimensional second-phase precipitates and spherical pores measuring 1-4 nm in diameter. A specific microstructural feature of irradiated boron carbide is the formation of 30 nm wide zones that are free from pores and other radiation-induced defects near the gain boundaries. The obtained results indicate that irradiation of boron carbide in the 350-370 C range leads to the formation of several types of defects that can be detected by their image contrast under different conditions of photographing.

  1. Low energy electron irradiation of an apple

    E-Print Network [OSTI]

    Brescia, Giovanni Batista

    2002-01-01T23:59:59.000Z

    simulation. A software package, MCNP (Monte Carlo N-Particle), was used to simulate an electron beam irradiation with a 1.0, 1.5 and 2.0 MeV sources on an apple modeled by interconnecting two spheres. The apple radii were 4.4 cm (perpendicular to its axis...

  2. SIPS: Solar Irradiance Prediction System Stefan Achleitner

    E-Print Network [OSTI]

    Cerpa, Alberto E.

    SIPS: Solar Irradiance Prediction System Stefan Achleitner Computer Science and Engineering-scaling capacities of renewable energy sources such as wind and solar. However, variability and uncertainty in power potentially limit the impact of fluctuations in solar power generation, specifically in cloudy days when

  3. Response of neutron-irradiated RPV steels to thermal annealing

    SciTech Connect (OSTI)

    Iskander, S.K.; Sokolov, M.A.; Nanstad, R.K.

    1997-03-01T23:59:59.000Z

    One of the options to mitigate the effects of irradiation on reactor pressure vessels (RPVs) is to thermally anneal them to restore the fracture toughness properties that have been degraded by neutron irradiation. This paper summarizes experimental results of work performed at the Oak Ridge National Laboratory (ORNL) to study the annealing response of several irradiated RPV steels.

  4. Total solar irradiance during the Holocene F. Steinhilber,1

    E-Print Network [OSTI]

    Wehrli, Bernhard

    Total solar irradiance during the Holocene F. Steinhilber,1 J. Beer,1 and C. Fro¨hlich2 Received 20 solar irradiance covering 9300 years is presented, which covers almost the entire Holocene. This reconstruction is based on a recently observationally derived relationship between total solar irradiance

  5. Irradiation Embritlement in Alloy HT-­9

    SciTech Connect (OSTI)

    Serrano De Caro, Magdalena [Los Alamos National Laboratory

    2012-08-27T23:59:59.000Z

    HT-9 steel is a candidate structural and cladding material for high temperature lead-bismuth cooled fast reactors. In typical advanced fast reactor designs fuel elements will be irradiated for an extended period of time, reaching up to 5-7 years. Significant displacement damage accumulation in the steel is expected (> 200 dpa) when exposed to dpa-rates of 20-30 dpa{sub Fe}/y and high fast flux (E > 0.1 MeV) {approx}4 x 10{sup 15} n/cm{sup 2}s. Core temperatures could reach 400-560 C, with coolant temperatures at the inlet as low as 250 C, depending on the reactor design. Mechanical behavior in the presence of an intense fast flux and high dose is a concern. In particular, low temperature operation could be limited by irradiation embrittlement. Creep and corrosion effects in liquid metal coolants could set a limit to the upper operating temperature. In this report, we focus on the low temperature operating window limit and describe HT-9 embrittlement experimental findings reported in the literature that could provide supporting information to facilitate the consideration of a Code Case on irradiation effects for this class of steels in fast reactor environments. HT-9 has an extensive database available on irradiation performance, which makes it the best choice as a possible near-term candidate for clad, and ducts in future fast reactors. Still, as it is shown in this report, embrittlement data for very low irradiation temperatures (< 200 C) and very high radiation exposure (> 150 dpa) is scarce. Experimental findings indicate a saturation of DBTT shifts as a function of dose, which could allow for long lifetime cladding operation. However, a strong increase in DBTT shift with decreasing irradiation temperature could compromise operation at low service temperatures. Development of a deep understanding of the physics involved in the radiation damage mechanisms, together with multiscale computer simulation models of irradiation embrittlement will provide the basis to derive trendlines and quantitative engineering predictions.

  6. Climatology of Mid-latitude Ionospheric Disturbances from the Very Large Array Low-frequency Sky Survey

    E-Print Network [OSTI]

    Helmboldt, J F; Cotton, W D

    2012-01-01T23:59:59.000Z

    The results of a climatological study of ionospheric disturbances derived from observations of cosmic sources from the Very Large Array (VLA) Low-frequency Sky Survey (VLSS) are presented. We have used the ionospheric corrections applied to the 74 MHz interferometric data within the VLSS imaging process to obtain fluctuation spectra for the total electron content (TEC) gradient on spatial scales from a few to hundreds of kilometers and temporal scales from less than one minute to nearly an hour. The observations sample nearly all times of day and all seasons. They also span latitudes and longitudes from 28 deg. N to 40 deg. N and 95 deg. W to 114 deg. W, respectively. We have binned and averaged the fluctuation spectra according to time of day, season, and geomagnetic (Kp index) and solar (F10.7) activity. These spectra provide a detailed, multi-scale account of seasonal and intraday variations in ionospheric activity with wavelike structures detected at wavelengths between about 35 and 250 km. In some cases,...

  7. Sensitivity of ultrasonic nonlinearity to irradiated, annealed, and re-irradiated microstructure changes in RPV steels

    SciTech Connect (OSTI)

    Matlack, Katie [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Kim, J-Y. [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Wall, J.J. [Electric Power Research Institute (EPRI)] [Electric Power Research Institute (EPRI); Jacobs, L.J. [Georgia Institute of Technology, Atlanta] [Georgia Institute of Technology, Atlanta; Sokolov, Mikhail A [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    The planned life extension of nuclear reactors throughout the US and abroad will cause reactor vessel and internals materials to be exposed to more neutron irradiation than was originally intended. A nondestructive evaluation (NDE) method to monitor radiation damage would enable safe and cost-effective continued operation of nuclear reactors. Radiation damage in reactor pressure vessel (RPV) steels causes microstructural changes that leave the material in an embrittled state. Nonlinear ultrasound is an NDE technique quantified by the measurable acoustic nonlinearity parameter, which is sensitive to microstructural changes in metallic materials such as dislocations, precipitates and their combinations. Recent research has demonstrated the sensitivity of the acoustic nonlinearity parameter to increasing neutron fluence in representative RPV steels. The current work considers nonlinear ultrasonic experiments conducted on similar RPV steel samples that had a combination of irradiation, annealing, re-irradiation, and/or re-annealing to a total neutron fluence of 0.5 5 1019 n/cm2 (E > 1 MeV) at an irradiation temperature of 290 C. The acoustic nonlinearity parameter generally increased with increasing neutron fluence, and consistently decreased from the irradiated to the annealed state over different levels of neutron fluence. Results of the measured acoustic nonlinearity parameter are compared with those from previous measurements on other RPV steel samples. This comprehensive set of results illustrates the dependence of the measured acoustic nonlinearity parameter on neutron fluence, material composition, irradiation temperature and annealing.

  8. Effects of stress on microstructural evolution during irradiation

    SciTech Connect (OSTI)

    Gelles, D.S. [Pacific Northwest Lab., Richland, VA (United States)

    1992-12-31T23:59:59.000Z

    Many theories have been postulated to describe irradiation creep but few have been supported with microstructural evidence. The purpose of this paper is to review microstructural studies of the effects of stress during irradiation in order to assess the validity of the available irradiation creep theories. Microstructural studies based on high voltage electron, ion, proton and neutron irradiation will be described, with major emphasis placed on interpreting behavior demonstrated in austenitic steels. Special attention will be given to work on fast neutron irradiated Nimonic PE16, a precipitation strengthened superalloy.

  9. Breaking the Crowther Limit: Combining Depth-Sectioning and Tilt Tomography for High-Resolution, Wide-Field 3D Reconstructions

    E-Print Network [OSTI]

    Hovden, Robert; Jiang, Yi; Wang, Deli; Yu, Yingchao; Abruna, Hector D; Elser, Veit; Muller, David A

    2014-01-01T23:59:59.000Z

    To date, high-resolution ( 6 nm) to appear blurred or missing. Here we demonstrate a three-dimensional imaging method that overcomes both these limits by combining through-focal depth sectioning and traditional tilt-series tomography to reconstruct extended objects, with high-resolution, in all three dimensions. The large convergence angle in aberration corrected instruments now becomes a benefit and not a hindrance to higher quality reconstructions. A through-focal reconstruction over a 390 nm 3D carbon support containing over one hundred dealloyed and nanoporous PtCu catalyst particles revealed with sub-nanometer detail the extensive and connected interior pore structure that is created by the dealloying instability.

  10. Observational evidence for a changing tilt of the accretion disk with respect to the orbital plane in Her X-1 over its 35 day cycle

    E-Print Network [OSTI]

    D. Klochkov; N. Shakura; K. Postnov; R. Staubert; J. Wilms; N. Ketsaris

    2007-11-12T23:59:59.000Z

    Analysis and interpretation of the Her X-1 X-ray light curve obtained with the ASM onbord RXTE over the period 1996 February to 2004 September is presented. We report that the features found previously in the averaged X-ray lightcurve are confirmed by the new RXTE/ASM data. In particular, anomalous dips and post-eclipse recoveries in two successive orbits in the short-on state are found to be prominent and stable details of the light curve. We argue that a change of the tilt of the accretion disk over the 35-day period is necessary to account for these features and show that our numerical model can explain such a behavior of the disk and reproduce the observed details of the light curve.

  11. Anderson-Gregory; Constable-Steven; Orcutt-John; Staudigel-Hubert; Tolstoy-Maya; Wyatt-Frank-K, Observing seafloor tilt on Axial Segment, Juan de Fuca Ridge. Eos, Transactions, American Geophysical

    E-Print Network [OSTI]

    Menke, William

    -Frank-K, Observing seafloor tilt on Axial Segment, Juan de Fuca Ridge. Eos, Transactions, American Geophysical Union de Fuca Ridge. Geophysical Research Letters.22; 2, Pages 147-150. 1995. Baker-Edward-T; Fox eruption of Axial Volcano, Juan de Fuca Ridge. Geophysical Research Letters.26; 23, Pages 3445-3448. 1999

  12. JOURNAL DE PHYSIQUE Colloque C1, supplgment au no2, Tome 40,fgvrier 1979,page C1-295 POLARIZATION MEASUREMENTS OF TWO He I TRANSITIONS USING BEAM-TILTED-FOIL EXCITATION*

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    these measure- ments, for at least two transitions, to try to establish a trend through as large a foil tilt be rotated by a step- ping motor with reproducibility of axis position of 0.1'. The entrance and exit slits acquisition and experimental control have been previously described.' Nominally 5 ug/cm2 carbon foils were

  13. Materials Modification Under Ion Irradiation: JANNUS Project

    SciTech Connect (OSTI)

    Serruys, Y.; Trocellier, P. [CEA-Saclay, DEN/DMN/SRMP, 91191 Gif-sur-Yvette Cedex (France); Ruault, M.-O.; Henry, S.; Kaietasov, O. [CSNSM, Bat. 104, Orsay Campus (France); Trouslard, Ph. [INSTN, CEA-Saclay, 91191 Gif-sur-Yvette Cedex (France)

    2004-12-01T23:59:59.000Z

    JANNUS (Joint Accelerators for Nano-Science and Nuclear Simulation) is a project designed to study the modification of materials using multiple ion beams and in-situ TEM observation. It will be a unique facility in Europe for the study of irradiation effects, the simulation of material damage due to irradiation and in particular of combined effects. The project is also intended to bring together experimental and modelling teams for a mutual fertilisation of their activities. It will also contribute to the teaching of particle-matter interactions and their applications. JANNUS will be composed of three accelerators with a common experimental chamber and of two accelerators coupled to a 200 kV TEM.

  14. Gamma irradiation in a saturated tuff environment

    SciTech Connect (OSTI)

    Bates, J.K.; Oversby, V.M.

    1984-12-31T23:59:59.000Z

    The influence of gamma irradiation on the reaction of actinide doped SRL 165 and PNL 76-68 glasses in a saturated tuff environment has been studied in a series of tests lasting up to 56 days. The reaction, and subsequent actinide release, of both glasses depends on the dynamic interaction between radiolysis effects which cause the solution pH to become more acidic and glass reaction which drives the pH more basic. The use of large gamma irradiation dose rates to accelerate reactions that would occur in an actual repository radiation field may affect this dynamic balance by unduly influencing the mechanism of the glass-water reaction. Comparisons are made between the present results and data obtained by reacting the same or similar glasses using MCC-1 and NNWSI rock cup procedures. 11 references, 3 figures.

  15. Neutron irradiation of beryllium: Recent Russian results

    SciTech Connect (OSTI)

    Gelles, D.S. [Pacific Northwest Lab., Richland, VA (United States)

    1992-12-31T23:59:59.000Z

    Results on postirradiation tensile and compression testing, swelling and bubble growth during annealing for various grades of beryllium are presented. It is shown that swelling at temperatures above 550{degrees}C is sensitive to material condition and response is correlated with oxygen content. Swelling on the order of 15% can be expected at 700{degrees}C for doses on the order of 10{sup 22} n/cm{sup 2}. Bubble growth response depends on irradiation fluence.

  16. ARM - Measurement - Longwave narrowband upwelling irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwelling irradiance ARM Data Discovery Browse Data

  17. ARM - Measurement - Net broadband total irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwelling irradiance ARM DatagovMeasurementsNet

  18. ARM - Measurement - Shortwave broadband direct downwelling irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarization ARMdownwelling irradiance ARM

  19. ARM - Measurement - Shortwave broadband direct normal irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarization ARMdownwelling irradiance

  20. ARM - Measurement - Shortwave narrowband diffuse upwelling irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarizationupwelling irradiance ARM Data

  1. ARM - Measurement - Shortwave narrowband direct downwelling irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarizationupwelling irradiance ARM

  2. ARM - Measurement - Shortwave narrowband direct normal irradiance

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwellingpolarizationupwelling irradiance ARMnormal

  3. Irradiation response and stability of nanoporous materials

    SciTech Connect (OSTI)

    Fu, Engang [Los Alamos National Laboratory; Wang, Yongqiang [Los Alamos National Laboratory; Serrano De Caro, Magdalena [Los Alamos National Laboratory; Caro, Jose A. [Los Alamos National Laboratory; Zepeda-Ruiz, L [Lawrence Livermore national Laboratory; Bringa, E. [CONICET, Universidad de Cuyo, Argentina; Nastasi, Mike [University of Nebraska, Lincoln, NE; Baldwin, Jon K. [Los Alamos National Laboratory

    2012-08-28T23:59:59.000Z

    Nanoporous materials consist of a regular organic or inorganic framework supporting a regular, porous structure. Pores are by definition roughly in the nanometre range, that is between 0.2 nm and 100 nm. Nanoporous materials can be subdivided into 3 categories (IUPAC): (1) Microporous materials - 0.2-2 nm; (2) Mesoporous materials - 2-50 nm; and (3) Macroporous materials - 50-1000 nm. np-Au foams were successfully synthesized by de-alloying process. np-Au foams remain porous structure after Ne ion irradiation to 1 dpa. Stacking Fault Tetrahedra (SFTs) were observed in RT irradiated np-Au foams under the highest and intermediate fluxes, but not under the lowest flux. SFTs were not observed in LNT irradiated np-Au foams under all fluxes. The vacancy diffusivity in Au at RT is high enough so that the vacancies have enough time to agglomerate and then collapse to form SFTs. The high ion flux creates more damage per unit time; vacancies don't have enough time to diffuse or recombine. As a result, SFTs were formed at high ion fluxes.

  4. Magnetic phase formation in irradiated austenitic alloys

    SciTech Connect (OSTI)

    Gussev, Maxim N [ORNL] [ORNL; Busby, Jeremy T [ORNL] [ORNL; Tan, Lizhen [ORNL] [ORNL; Garner, Francis A. [Radiation Effects Consulting, Richland, WA] [Radiation Effects Consulting, Richland, WA

    2014-01-01T23:59:59.000Z

    Austenitic alloys are often observed to develop magnetic properties during irradiation, possibly associated with radiation-induced acceleration of the ferrite phase. Some of the parametric sensitivities of this phenomenon have been addressed using a series of alloys irradiated in the BOR-60 reactor at 593K. The rate of development of magnetic phase appears to be sensitive to alloy composition. To the first order, the largest sensitivities to accelerate ferrite formation, as explored in this experiment, are associated with silicon, carbon and manganese and chromium. Si, C, and Mn are thought to influence diffusion rates of point defects while Cr plays a prominent role in defining the chromium equivalent and therefore the amount of ferrite at equilibrium. Pre-irradiation cold working was found to accelerate ferrite formation, but it can play many roles including an effect on diffusion, but on the basis of these results the dominant role or roles of cold-work cannot be identified. Based on the data available, ferrite formation is most probably associated with diffusion.

  5. Upgrade to the Birmingham Irradiation Facility

    E-Print Network [OSTI]

    Dervan, P; Hodgson, P; Marin- Reyes; Parker, K; Wilson, J; Baca, M

    2015-01-01T23:59:59.000Z

    The Birmingham Irradiation Facility was developed in 2013 at the University of Birmingham using the Medical Physics MC40 cyclotron. It can achieve High Luminosity LHC (HL-LHC) fluences of 10^15 (1 MeV neutron equivalent (neq)) cm^-2 in 80 s with proton beam currents of 1 ?A and so can evaluate effectively the performance and durability of detector technologies and new components to be used for the HL-LHC. Irradiations of silicon sensors and passive materials can be carried out in a temperature controlled cold box which moves continuously through the homogenous beamspot. This movement is provided by a pre-configured XY-axis Cartesian robot scanning system. In 2014 the cooling system and cold box were upgraded from a recirculating glycol chiller system to a liquid nitrogen evaporative system. The new cooling system achieves a stable temperature of 50 1C in 30 min and aims to maintain sub-0 1C temperatures on the sensors during irradiations. This paper reviews the design, development, commissioning and perform...

  6. Evaluation of Neutron Irradiated Silicon Carbide and Silicon Carbide Composites

    SciTech Connect (OSTI)

    Newsome G, Snead L, Hinoki T, Katoh Y, Peters D

    2007-03-26T23:59:59.000Z

    The effects of fast neutron irradiation on SiC and SiC composites have been studied. The materials used were chemical vapor deposition (CVD) SiC and SiC/SiC composites reinforced with either Hi-Nicalon{trademark} Type-S, Hi-Nicalon{trademark} or Sylramic{trademark} fibers fabricated by chemical vapor infiltration. Statistically significant numbers of flexural samples were irradiated up to 4.6 x 10{sup 25} n/m{sup 2} (E>0.1 MeV) at 300, 500 and 800 C in the High Flux Isotope Reactor at Oak Ridge National Laboratory. Dimensions and weights of the flexural bars were measured before and after the neutron irradiation. Mechanical properties were evaluated by four point flexural testing. Volume increase was seen for all bend bars following neutron irradiation. Magnitude of swelling depended on irradiation temperature and material, while it was nearly independent of irradiation fluence over the fluence range studied. Flexural strength of CVD SiC increased following irradiation depending on irradiation temperature. Over the temperature range studied, no significant degradation in mechanical properties was seen for composites fabricated with Hi-Nicalon{trademark} Type-S, while composites reinforced with Hi-Nicalon{trademark} or Sylramic fibers showed significant degradation. The effects of irradiation on the Weibull failure statistics are also presented suggesting a reduction in the Weibull modulus upon irradiation. The cause of this potential reduction is not known.

  7. Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation

    E-Print Network [OSTI]

    Booij, Wilfred Edwin

    Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation Wilfred Edwin Booij Gonville and Caius College Cambridge A dissertation submitted for the degree of Doctor of Philosophy at the University of Cambridge December 1997... Summary Josephson Junctions and Devices fabricated by Focused Electron Beam Irradiation The irradiation of high Tc superconducting thin films with a focused electron beam, such as that obtained in a scanning transmission electron microscope (STEM), can...

  8. NANOSTRUCTURE PATTERNING UNDER ENERGETIC PARTICLE BEAM IRRADIATION

    SciTech Connect (OSTI)

    Wang, Lumin [Regents of the University of Michigan; Lu, Wei [Regents of the University of Michigan

    2013-01-31T23:59:59.000Z

    Energetic ion bombardment can lead to the development of complex and diverse nanostructures on or beneath the material surface through induced self-organization processes. These self-organized structures have received particular interest recently as promising candidates as simple, inexpensive, and large area patterns, whose optical, electronic and magnetic properties are different from those in the bulk materials [1-5]. Compared to the low mass efficiency production rate of lithographic methods, these self-organized approaches display new routes for the fabrication of nanostructures over large areas in a short processing time at the nanoscale, beyond the limits of lithography [1,4]. Although it is believed that surface nanostructure formation is based on the morphological instability of the sputtered surface, driven by a kinetic balance between roughening and smoothing actions [6,7], the fundamental mechanisms and experimental conditions for the formation of these nanostructures has still not been well established, the formation of the 3-D naopatterns beneath the irradiated surface especially needs more exploration. During the last funding period, we have focused our efforts on irradiation-induced nanostructures in a broad range of materials. These structures have been studied primarily through in situ electron microscopy during electron or ion irradiation. In particular, we have performed studies on 3-D void/bubble lattices (in metals and CaF2), embedded sponge-like porous structure with uniform nanofibers in irradiated semiconductors (Ge, GaSb, and InSb), 2-D highly ordered pattern of nanodroplets (on the surface of GaAs), hexagonally ordered nanoholes (on the surface of Ge), and 1-D highly ordered ripple and periodic arrays (of Cu nanoparticles) [3,8-11]. The amazing common feature in those nanopatterns is the uniformity of the size of nanoelements (nanoripples, nanodots, nanovoids or nanofibers) and the distance separating them. Our research focuses on the understanding of fundamental scientific basis for the irradiation-induced self-organization processes. The fundamental physical mechanisms underlying ordered pattern formation, which include defect production and migration, ion sputtering, redeposition, viscous flow and diffusion, are investigated through a combination of modeling and in situ and ex-situ observations [3,9,11]. In addition, these nanostructured materials exhibit considerable improvement of optical properties [9,12,13]. For example, patterned Ge with a hexagonally ordered, honeycomb-like structure of nanoscale holes possesses a high surface area and a considerably blue-shifted energy gap [9], and oxidation of ordered Ga droplets shows noticeable enhancement of optical transmission [12]. This research has addressed nanopattern formation in a variety of materials under ion bombardment and provided a fundamental understanding of the dynamic mechanisms involved. In addition, have also stared to systematically investigate pattern formation under ion irradiation for more systems with varied experimental conditions and computation, including the collaboration with Dr. Veena Tikare of Sandia National Laboratory with a hybrid computation method at the ending this grant. A more detailed relationship between nanostructure formation and experimental conditions will be revealed with our continued efforts.

  9. FY 2013 Summary Report: Post-Irradiation Examination of Zircaloy...

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

    fiscal year 2013 are provided and include information derived from: 1) irradiation of hydrogen-doped zircaloy cladding in High Flux Isotope Reactor (HFIR); 2) mechanical...

  10. Neutron Irradiation of Hydrided Cladding Material in HFIR Summary...

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

    Summary of Initial Activities Irradiation is known to have a significant impact on the properties and performance of Zircaloy cladding and structural materials (material...

  11. au ion irradiation: Topics by E-print Network

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

    under laser irradiation of Au nanoparticles in the presence of Thorium aqua-ions CERN Preprints Summary: Initiation of nuclear reactions in Thorium nuclei is experimentally...

  12. acute uv irradiation: Topics by E-print Network

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

    products, e.g., OH radicals, with the aid of UV irradiation by microwave discharge electrodeless lamp, photo-catalysts, and auxiliary oxidants. The results of...

  13. Photoinduced Formation of Zinc Nanoparticles by UV Laser Irradiation...

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

    metallic Zn nanoparticles growing on the exposed surface of the crystal. Higher fluence laser exposure generates accumulated surface metal just outside of the irradiated spot. We...

  14. Irradiation-induced defect clustering and amorphization in silicon...

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

    guidance on experimental approaches to reveal the onset of these processes. Citation: Weber WJ, and F Gao.2010."Irradiation-induced defect clustering and amorphization in silicon...

  15. Modification of Defect Structures in Graphene by Electron Irradiation...

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

    Modification of Defect Structures in Graphene by Electron Irradiation: Ab Initio Molecular Dynamics Simulations. Modification of Defect Structures in Graphene by Electron...

  16. Dynamic Recovery in Silicate-Apatite Structures Under Irradiation...

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

    Recovery in Silicate-Apatite Structures Under Irradiation and Implications for Long-Term Immobilization of Actinides. Dynamic Recovery in Silicate-Apatite Structures Under...

  17. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    on different size scales within bone, as well as the role of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging and...

  18. apres irradiation globale: Topics by E-print Network

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

    necessary for the evaluation of global irradiance on inclined surface which is needed for photovoltaic Boyer, Edmond 7 Caractristiques lectriques de diodes Au-Si(N) ralises aprs...

  19. Response of Strontium Titanate to Ion and Electron Irradiation...

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

    interface under electron irradiation. Citation: Zhang Y, J Lian, Z Zhu, WD Bennett, LV Saraf, JL Rausch, CA Hendricks, RC Ewing, and WJ Weber.2009."Response of...

  20. Environmental Assessment LEAD TEST ASSEMBLY IRRADIATION AND ANALYSIS

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

    10 Environmental Assessment LEAD TEST ASSEMBLY IRRADIATION AND ANALYSIS WATTS BAR NUCLEAR PLANT, TENNESSEE AND HANFORD SITE, RICHLAND, WASHINGTON U. S. DEPARTMENT OF ENERGY...

  1. Emulation of reactor irradiation damage using ion beams

    SciTech Connect (OSTI)

    G. S. Was; Z. Jiao; E. Beckett; A. M. Monterrosa; O. Anderoglu; B. H. Sencer; M. Hackett

    2014-10-01T23:59:59.000Z

    The continued operation of existing light water nuclear reactors and the development of advanced nuclear reactor depend heavily on understanding how damage by radiation to levels degrades materials that serve as the structural components in reactor cores. The first high dose ion irradiation experiments on a ferritic-martensitic steel showing that ion irradiation closely emulates the full radiation damage microstructure created in-reactor are described. Ferritic-martensitic alloy HT9 (heat 84425) in the form of a hexagonal fuel bundle duct (ACO-3) accumulated 155 dpa at an average temperature of 443°C in the Fast Flux Test Facility (FFTF). Using invariance theory as a guide, irradiation of the same heat was conducted using self-ions (Fe++) at 5 MeV at a temperature of 460°C and to a dose of 188 displacements per atom. The void swelling was nearly identical between the two irradiations and the size and density of precipitates and loops following ion irradiation are within a factor of two of those for neutron irradiation. The level of agreement across all of the principal microstructure changes between ion and reactor irradiations establishes the capability of tailoring ion irradiations to emulate the reactor-irradiated microstructure.

  2. alpha particle irradiation: Topics by E-print Network

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

    5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  3. alpha particles irradiation: Topics by E-print Network

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

    5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  4. alpha particle irradiated: Topics by E-print Network

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

    5 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  5. apres irradiation alpha: Topics by E-print Network

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

    Edmond 8 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  6. Microstructural examination of irradiated vanadium alloys

    SciTech Connect (OSTI)

    Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States); Chung, H.M. [Argonne National Lab., IL (United States)

    1997-04-01T23:59:59.000Z

    Microstructural examination results are reported for a V-5Cr-5Ti unirradiated control specimens of heat BL-63 following annealing at 1050{degrees}C, and V-4Cr-4Ti heat BL-47 irradiated in three conditions from the DHCE experiment: at 425{degrees}C to 31 dpa and 0.39 appm He/dpa, at 600{degrees}C to 18 dpa and 0.54 appm He/dpa and at 600{degrees}C to 18 dpa and 4.17 appm He/dpa.

  7. Mitigation of irradiation embrittlement by annealing

    SciTech Connect (OSTI)

    Amayev, A.D.; Kryukov, A.M.; Levit, V.I.; Platonov, P.A.; Sokolov, M.A. [Kurchatov Inst., Moscow (Russian Federation)

    1996-12-31T23:59:59.000Z

    The main results of a complex investigation carried out in Russia of post irradiation annealing and reembrittlement of WWER-440 reactor pressure vessel materials are presented. The dependence of the Charpy transition temperature recovery on annealing temperature and fluence was established. Charpy specimens were reirradiated after annealing at 340, 380, 420, and 460 C. Experimental values of the Charpy transition temperature after reirradiation are compared to that predicted by three methods. At annealing temperatures equal to or above 420 C, results of the analysis indicate that, of the methods investigated, the lateral shift method gives the best result for estimating the transition temperature shift due to reirradiation.

  8. Evolution of the nanostructure OF VVER-1000 RPV materials under neutron irradiation and post irradiation annealing

    SciTech Connect (OSTI)

    Miller, Michael K [ORNL; Chernobaeva, A. A. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Shtrombakh, Ya. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Erak, D. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Zabusov, Oleg O. [Russian Research Center, Kurchatov Institute, Moscow, Russia; Russell, Kaye F [ORNL; Nanstad, Randy K [ORNL

    2009-01-01T23:59:59.000Z

    A high nickel VVER-1000 (15Kh2NMFAA) base metal (1.34 wt% Ni, 0.47% Mn, 0.29% Si and 0.05% Cu), and a high nickel (12Kh2N2MAA) weld metal (1.77 wt% Ni, 0.74% Mn, 0.26% Si and 0.07% Cu) have been characterized by atom probe tomography to determine the changes in the microstructure during neutron irradiation to high fluences. The base metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 14.9 x 10{sup 23} m{sup -2} (E > 0.5 MeV), and the weld metal was studied in the unirradiated condition and after neutron irradiation to fluences between 2.4 and 11.5 x 10{sup 23} m{sup -2} (E > 0.5 MeV). High number densities of 2-nm-diameter Ni-, Si- and Mn-enriched nanoclusters were found in the neutron irradiated base and weld metals. No significant copper enrichment was associated with these nanoclusters and no copper-enriched precipitates were observed. The number densities of these nanoclusters correlate with the shifts in the {Delta}T{sub 41 J} ductile-to-brittle transition temperature. These nanoclusters were present after a post irradiOffice of Science (US)C, but had dissolved into the matrix after 24 h at 450 C. Phosphorus, nickel, silicon and to a lesser extent manganese were found to be segregated to the dislocations.

  9. Analysis of tritium transport in irradiated beryllium

    SciTech Connect (OSTI)

    Cho, S.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States)

    1994-12-31T23:59:59.000Z

    Analysis of the beryllium tritium release results with simple analytical models indicated that tritium behavior in Be is not dominated by one simple mechanism, but by a combination of several mechanisms including surface processes and helium bubbles. A model was developed and the initial version of the model included tritium diffusion in the beryllium and the beryllium oxide, second order desorption at the solid/gas interface and diffusion through interconnected porosity. Fundamental data, tritium diffusion and desorption coefficients for Be and BeO, were derived from experimental data using the model. Beryllium is a metal to which one can generally apply the concepts of diffusion, solubility, surface processes and traps. Tritium transport in the irradiated beryllium is affected by processes occurring in the bulk, He bubbles, the bulk/surface and surface/gas interfaces. There are two types of solid/gas surfaces in the irradiated Be. One is the surface at the pure Be/He bubble interface where no oxide layer exists and the other is the surface at the BeO layer/purge gas interface. Although the material characteristics of the Be and BeO layer are different and have different activation barriers, the surface processes can be applied to both interfaces.

  10. Optimisation of buildings' solar irradiation availability

    SciTech Connect (OSTI)

    Kaempf, Jerome Henri; Montavon, Marylene; Bunyesc, Josep; Robinson, Darren [Solar Energy and Building Physics Laboratory, Station 18, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland); Bolliger, Raffaele [Industrial Energy Systems Laboratory, Station 9, Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland)

    2010-04-15T23:59:59.000Z

    In order to improve the sustainability of new and existing urban settlements it is desirable to maximise the utilisation of the solar energy incident on the building envelope, whether by passive or active means. To this end we have coupled a multi-objective optimisation algorithm with the backwards ray tracing program RADIANCE which itself uses a cumulative sky model for the computation of incident irradiation (W h/m{sup 2}) in a single simulation. The parameters to optimise are geometric (the height of buildings up to their facade and the height and orientation of roofs), but with the constraint of maintaining an overall built volume, and the objective function is heating season solar irradiation offset by envelope heat losses. This methodology has been applied to a range of urban typologies and produces readily interpretable results. The focus of this work is on the design of new urban forms but the method could equally be applied to examine the relative efficiency of existing urban settlements, by comparison of existing forms with the calculated optima derived from relevant specifications of the building envelope. (author)

  11. LWRS ATR Irradiation Testing Readiness Status

    SciTech Connect (OSTI)

    Kristine Barrett

    2012-09-01T23:59:59.000Z

    The Light Water Reactor Sustainability (LWRS) Program was established by the U.S. Department of Energy Office of Nuclear Energy (DOE-NE) to develop technologies and other solutions that can improve the reliability, sustain the safety, and extend the life of the current reactors. The LWRS Program is divided into four R&D Pathways: (1) Materials Aging and Degradation; (2) Advanced Light Water Reactor Nuclear Fuels; (3) Advanced Instrumentation, Information and Control Systems; and (4) Risk-Informed Safety Margin Characterization. This report describes an irradiation testing readiness analysis in preparation of LWRS experiments for irradiation testing at the Idaho National Laboratory (INL) Advanced Test Reactor (ATR) under Pathway (2). The focus of the Advanced LWR Nuclear Fuels Pathway is to improve the scientific knowledge basis for understanding and predicting fundamental performance of advanced nuclear fuel and cladding in nuclear power plants during both nominal and off-nominal conditions. This information will be applied in the design and development of high-performance, high burn-up fuels with improved safety, cladding integrity, and improved nuclear fuel cycle economics

  12. A Near-Infrared Photometric Study of the Low Latitude Globular Clusters Liller 1, Djorgovski 1, HP 1, and NGC 6528

    E-Print Network [OSTI]

    T. J. Davidge

    1999-09-23T23:59:59.000Z

    Images recorded through J, H, Ks, 2.2 micron continuum, and 2.3 micron CO filters are used to investigate the stellar contents of the low Galactic latitude globular clusters NGC 6528, Liller 1, Djorgovski 1, and HP 1, as well as surrounding bulge fields. Metallicities are estimated for the latter three clusters by comparing the colors and CO indices of giant branch stars with those in other clusters and the bulge, while reddenings are estimated from the colors of bright bulge stars in the surrounding fields. In some cases the metallicities and reddenings are significantly different from previous estimates.

  13. Damage Profiles and Ion Distribution in Pt-irradiated SiC. |...

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

    Damage Profiles and Ion Distribution in Pt-irradiated SiC. Damage Profiles and Ion Distribution in Pt-irradiated SiC. Abstract: Single crystalline 6H-SiC samples were irradiated at...

  14. SHORT COMMUNICATION UV microspot irradiator at Columbia University

    E-Print Network [OSTI]

    Brenner, David Jonathan

    available for radiation biology research at the Radiological Research Accelerator Facility (RARAF), Columbia: 26 May 2013 Ó Springer-Verlag Berlin Heidelberg 2013 Abstract The Radiological Research Accelerator Facility at Columbia University has recently added a UV microspot irradiator to a microbeam irradiation

  15. IRRADIANCE MAPS APPLIED FOR THE PERFORMANCE ASSESSMENT OF PV SYSTEMS

    E-Print Network [OSTI]

    Heinemann, Detlev

    IRRADIANCE MAPS APPLIED FOR THE PERFORMANCE ASSESSMENT OF PV SYSTEMS - A CASE STUDY FOR THE GERMAN energy yield of a PV system,methods based on irradiance maps published by weather services or others-connected PV systems. DATA USED Hourly time series from ground and satellite-derived horizontal global

  16. SHORT COMMUNICATION Microbeam irradiation of C. elegans nematode in microfluidic

    E-Print Network [OSTI]

    Brenner, David Jonathan

    SHORT COMMUNICATION Microbeam irradiation of C. elegans nematode in microfluidic channels M implemented a microfluidic tool for microbeam irradiation of Caenorhabditis elegans. The device allows into the microfluidic device through liquid flow between an inlet and an outlet, and the size of each microchannel

  17. Retention of Hydrogen Isotopes in Neutron Irradiated Tungsten

    SciTech Connect (OSTI)

    Yuji Hatano; Masashi Shimada; Yasuhisa Oya; Guoping Cao; Makoto Kobayashi; Masanori Hara; Brad J. Merrill; Kenji Okuno; Mikhail A. Sokolov; Yutai Katoh

    2013-03-01T23:59:59.000Z

    To investigate the effects of neutron irradiation on hydrogen isotope retention in tungsten, disk-type specimens of pure tungsten were irradiated in the High Flux Isotope Reactor in Oak Ridge National Laboratory followed by exposure to high flux deuterium (D) plasma in Idaho National Laboratory. The results obtained for low dose n-irradiated specimens (0.025 dpa for tungsten) are reviewed in this paper. Irradiation at coolant temperature of the reactor (around 50 degrees C) resulted in the formation of strong trapping sites for D atoms. The concentrations of D in n-irradiated specimens were ranging from 0.1 to 0.4 mol% after exposure to D plasma at 200 and 500 degrees C and significantly higher than those in non-irradiated specimens because of D-trapping by radiation defects. Deep penetration of D up to a depth of 50-100 µm was observed at 500 degrees C. Release of D in subsequent thermal desorption measurements continued up to 900 degrees C. These results were compared with the behaviour of D in ion-irradiated tungsten, and distinctive features of n-irradiation were discussed.

  18. Standard Guide for Packaging Materials for Foods to Be Irradiated

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2009-01-01T23:59:59.000Z

    1.1 This guide provides a format to assist producers and users of food packaging materials in selecting materials that have the desirable characteristics for their intended use and comply with applicable standards or government authorizations. It outlines parameters that should be considered when selecting food-contact packaging materials intended for use during irradiation of prepackaged foods and it examines the criteria for fitness for their use. 1.2 This guide identifies known regulations and regulatory frameworks worldwide pertaining to packaging materials for holding foods during irradiation; but it does not address all regulatory issues associated with the selection and use of packaging materials for foods to be irradiated. It is the responsibility of the user of this guide to determine the pertinent regulatory issues in each country where foods are to be irradiated and where irradiated foods are distributed. 1.3 This guide does not address all of the food safety issues associated with the synergisti...

  19. Analyzing and simulating the variability of solar irradiance and solar PV powerplants

    E-Print Network [OSTI]

    Lave, Matthew S.

    2012-01-01T23:59:59.000Z

    Models of diffuse solar radiation, Renew Energ, 33 (2008) [solar irradiance for analyzing areally- totalized PV systems, Sol Energsolar irradiance for analyzing areally- totalized PV systems, Sol Energ

  20. Instrumentation to Enhance Advanced Test Reactor Irradiations

    SciTech Connect (OSTI)

    J. L. Rempe; D. L. Knudson; K. G. Condie; J. E. Daw; S. C. Taylor

    2009-09-01T23:59:59.000Z

    The Department of Energy (DOE) designated the Advanced Test Reactor (ATR) as a National Scientific User Facility (NSUF) in April 2007 to support U.S. leadership in nuclear science and technology. By attracting new research users - universities, laboratories, and industry - the ATR will support basic and applied nuclear research and development, further advancing the nation's energy security needs. A key component of the ATR NSUF effort is to prove new in-pile instrumentation techniques that are capable of providing real-time measurements of key parameters during irradiation. To address this need, an assessment of instrumentation available and under-development at other test reactors has been completed. Based on this review, recommendations are made with respect to what instrumentation is needed at the ATR and a strategy has been developed for obtaining these sensors. Progress toward implementing this strategy is reported in this document. It is anticipated that this report will be updated on an annual basis.

  1. Irradiation behavior of metallic fast reactor fuels

    SciTech Connect (OSTI)

    Pahl, R.G.; Porter, D.L.; Crawford, D.C.; Walters, L.C.

    1991-01-01T23:59:59.000Z

    Metallic fuels were the first fuels chosen for liquid metal cooled fast reactors (LMR's). In the late 1960's world-wide interest turned toward ceramic LMR fuels before the full potential of metallic fuel was realized. However, during the 1970's the performance limitations of metallic fuel were resolved in order to achieve a high plant factor at the Argonne National Laboratory's Experimental Breeder Reactor II. The 1980's spawned renewed interest in metallic fuel when the Integral Fast Reactor (IFR) concept emerged at Argonne National Laboratory. A fuel performance demonstration program was put into place to obtain the data needed for the eventual licensing of metallic fuel. This paper will summarize the results of the irradiation program carried out since 1985.

  2. Recovery of niobium from irradiated targets

    DOE Patents [OSTI]

    Phillips, Dennis R. (Los Alamos, NM); Jamriska, Sr., David J. (Los Alamos, NM); Hamilton, Virginia T. (Los Alamos, NM)

    1994-01-01T23:59:59.000Z

    A process for selective separation of niobium from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected form the group consisting of molybdenum, biobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the cationic resin; adjusting the pH of the second ion-containing solution to within a range of from about 5.0 to about 6.0; contacting the pH adjusting second ion-containing solution with a dextran-based material for a time to selectively separate niobium from the solution and recovering the niobium from the dextran-based material.

  3. Controlled doping of graphene using ultraviolet irradiation

    SciTech Connect (OSTI)

    Luo Zhengtang [Department of Chemical and Biomolecular Engineering, Hong Kong University of Science and Technology, Clear Water Bay (Hong Kong); Pinto, Nicholas J.; Davila, Yarely [Department of Physics and Electronics, University of Puerto Rico at Humacao, Humacao, 00792 (Puerto Rico); Charlie Johnson, A. T. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6396 (United States)

    2012-06-18T23:59:59.000Z

    The electronic properties of graphene are tunable via doping, making it attractive in low dimensional organic electronics. Common methods of doping graphene, however, adversely affect charge mobility and degrade device performance. We demonstrate a facile shadow mask technique of defining electrodes on graphene grown by chemical vapor deposition (CVD) thereby eliminating the use of detrimental chemicals needed in the corresponding lithographic process. Further, we report on the controlled, effective, and reversible doping of graphene via ultraviolet (UV) irradiation with minimal impact on charge mobility. The change in charge concentration saturates at {approx}2 Multiplication-Sign 10{sup 12} cm{sup -2} and the quantum yield is {approx}10{sup -5} e/photon upon initial UV exposure. This simple and controlled strategy opens the possibility of doping wafer-size CVD graphene for diverse applications.

  4. AGC-3 Irradiation Data Qualification Final Report

    SciTech Connect (OSTI)

    Laurence Hull

    2014-08-01T23:59:59.000Z

    The Graphite Technology Development Program will run a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The third experiment, Advanced Graphite Creep 3 (AGC 3), began with Advanced Test Reactor (ATR) Cycle 152B on November 27, 2012, and ended with ATR Cycle 155B on April 23, 2014. This report documents qualification of AGC 3 experiment irradiation monitoring data for use by the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Program for research and development activities required to design and license the first VHTR nuclear plant. Qualified data meet the requirements for data collection and use as described in the experiment planning and quality assurance documents. Failed data do not meet the requirements. Trend data may not meet the requirements, but may still provide some useable information. All thermocouples (TCs) functioned throughout the AGC 3 experiment. There was one interval between December 18, 2012, and December 20, 2012, where 10 NULL values were reported for various TCs. These NULL values were deleted from the Nuclear Data Management and Analysis System database. All temperature data are Qualified for use by the VHTR TDO Program. Argon, helium, and total gas flow data were within expected ranges and are Qualified for use by the VHTR TDO Program. Total gas flow was approximately 50 sccm through the AGC 3 experiment capsule. Helium gas flow was briefly increased to 100 sccm during ATR shutdowns. At the start of the AGC 3 experiment, moisture in the outflow gas line was stuck at a constant value of 335.6174 ppmv for the first cycle (Cycle 152B). When the AGC 3 experiment capsule was reinstalled in ATR for Cycle 154B, a new moisture filter was installed. Moisture data from Cycle 152B are Failed. All moisture data from the final three cycles (Cycles 154B, 155A, and 155B) are Qualified for use by the VHTR TDO Program.

  5. Surface Modification of Polymer Substrates by Oxygen Ion Irradiation

    SciTech Connect (OSTI)

    Takaoka, G. H.; Ryuto, H.; Araki, R.; Yakushiji, T. [Photonics and Electronics Science and Engineering Center, Kyoto University, Nishikyo, Kyoto 615-8510 (Japan)

    2008-11-03T23:59:59.000Z

    Oxygen cluster ions and/or monomer ions were used for the sputtering and the surface modification of polymers such as polycarbonate (PC) and polyethylene terephthalate (PET). For the case of oxygen cluster ion irradiation, the sputtered depth increased with increase of the acceleration voltage, and the sputtering yield was much larger than that by the monomer ion irradiation. The sputtered particles represented the polymer structure, which indicated that the bond scission by the cluster ion irradiation resulted in an ejection of monomer molecule through the intermolecular collision. On the other hand, for the oxygen monomer ion irradiation, the implanted depth increased with increase of the acceleration voltage, and the bond scission occurred at the deep region through the binary collision with the high energetic ions. Therefore, the sputtering yield for the polymer surfaces decreased, and the sputtering effect became very small. Furthermore, the simultaneous use of oxygen cluster and monomer ions was more effective for oxidation of the PET surfaces rather than the monomer ion irradiation or the cluster ion irradiation. As a result, the contact angle measurement showed that the wettability of the PET surfaces irradiated by the simultaneous use of oxygen cluster and monomer ions was much enhanced.

  6. AGC-1 Pre-Irradiation Data Report Status

    SciTech Connect (OSTI)

    William Windes

    2011-08-01T23:59:59.000Z

    The Next Generation Nuclear Plant (NGNP) Graphite R&D program is currently measuring irradiated material property changes in several grades of nuclear graphite for predicting their behavior and operating performance within the core of new Very High Temperature Reactor (VHTR) designs. The Advanced Graphite Creep (AGC) experiment consisting of six irradiation capsules will generate this irradiated graphite performance data for NGNP reactor operating conditions. All samples in the experiment will be fully characterized before irradiation, irradiated in the Advanced Test Reactor (ATR), and then re-examined to determine the irradiation induced changes to key materials properties in the different graphite grades. The information generated during the AGC experiment will be utilized for NRC licensing of NGNP reactor designs, shared with international collaborators in the Generation IV Information Forum (GIF), and eventually utilized in ASME design code for graphite nuclear applications. This status report will describe the process the NGNP Graphite R&D program has developed to record the AGC1 pre-irradiation examination data.

  7. Indoor and Outdoor Spectroradiometer Intercomparison for Spectral Irradiance Measurement

    SciTech Connect (OSTI)

    Habte, A.; Andreas, A.; Ottoson, L.; Gueymard, C.; Fedor, G.; Fowler, S.; Peterson, J.; Naranen, R.; Kobashi, T.; Akiyama, A.; Takagi, S.

    2014-05-01T23:59:59.000Z

    This report details the global spectral irradiance intercomparison using spectroradiometers that was organized by the National Renewable Energy Laboratory's Solar Radiation Research Laboratory. The intercomparison was performed both indoors and outdoors on September 17, 2013. Five laboratories participated in the intercomparison using 10 spectroradiometers, and a coordinated measurement setup and a common platform were employed to compare spectral irradiances under both indoor and outdoor conditions. The intercomparison aimed to understand the performance of the different spectroradiometers and to share knowledge in making spectral irradiance measurements. This intercomparison was the first of its kind in the United States.

  8. AGC-2 Irradiation Data Qualification Final Report

    SciTech Connect (OSTI)

    Laurence C. Hull

    2012-07-01T23:59:59.000Z

    The Graphite Technology Development Program will run a series of six experiments to quantify the effects of irradiation on nuclear grade graphite. The second Advanced Graphite Creep (AGC) experiment (AGC-2) began with Advanced Test Reactor (ATR) Cycle 149A on April 12, 2011, and ended with ATR Cycle 151B on May 5, 2012. The purpose of this report is to qualify AGC-2 irradiation monitoring data following INL Management and Control Procedure 2691, Data Qualification. Data that are Qualified meet the requirements for data collection and use as described in the experiment planning and quality assurance documents. Data that do not meet the requirements are Failed. Some data may not quite meet the requirements, but may still provide some useable information. These data are labeled as Trend. No Trend data were identified for the AGC-2 experiment. All thermocouples functioned throughout the AGC-2 experiment. There was one instance where spurious signals or instrument power interruption resulted in a recorded temperature value being well outside physical reality. This value was identified and labeled as Failed data. All other temperature data are Qualified. All helium and argon gas flow data are within expected ranges. Total gas flow was approximately 50 sccm through the capsule. Helium gas flow was briefly increased to 100 sccm during reactor shutdown. All gas flow data are Qualified. At the start of the experiment, moisture in the outflow gas line increased to 200 ppmv then declined to less than 10 ppmv over a period of 5 days. This increase in moisture coincides with the initial heating of the experiment and drying of the system. Moisture slightly exceeded 10 ppmv three other times during the experiment. While these moisture values exceed the 10 ppmv threshold value, the reported measurements are considered accurate and to reflect moisture conditions in the capsule. All moisture data are Qualified. Graphite creep specimens are subjected to one of three loads, 393 lbf, 491 lbf, or 589 lbf. Loads were consistently within 5% of the specified values throughout the experiment. Stack displacement increased consistently throughout the experiment with total displacement ranging from 1 to 1.5 inches. No anomalous values were identified. During reactor outages, a set of pneumatic rams are used to raise the stacks of graphite creep specimens to ensure the specimens have not become stuck within the test train. This stack raising was performed after all cycles when the capsule was in the reactor. All stacks were raised successfully after each cycle. The load and displacement data are Qualified

  9. The modelling of irradiation-enhanced phosphorus segregation in neutron irradiated reactor pressure vessel submerged-arc welds

    SciTech Connect (OSTI)

    Druce, S.G.; English, C.A.; Foreman, A.J.E.; McElroy, R.J.; Vatter, I.A. [AEA Technology, Didcot (United Kingdom). Harwell Lab.; Bolton, C.J.; Buswell, J.T.; Jones, R.B. [Nuclear Electric, Berkeley (United Kingdom). Berkeley Technology Centre

    1996-12-31T23:59:59.000Z

    Recent results on neutron-irradiated RPV submerged-arc welds have revealed grain boundary segregation of phosphorus during irradiation, which may lead to intergranular fracture. However, the experimental database is insufficient to define the dependence of the process on variables such ad dose, dose-rate and temperature. This paper describes work in which two existing models of phosphorus segregation, under thermal or irradiation conditions, have been developed to obtain predictions of these dependencies. The critical parameters in the models have been adjusted to give consistency with the available reference data, and predictions have been made of the dependence of segregation on a number of variables.

  10. Solar irradiance forecasting at multiple time horizons and novel methods to evaluate uncertainty

    E-Print Network [OSTI]

    Marquez, Ricardo

    2012-01-01T23:59:59.000Z

    Solar irradiance data . . . . . . . . . . . . .Accuracy . . . . . . . . . . . . . . . . . Solar Resourcev Uncertainty In Solar Resource: Forecasting

  11. Carbon Characterization Laboratory Readiness to Receive Irradiated Graphite Samples

    SciTech Connect (OSTI)

    Karen A. Moore

    2011-05-01T23:59:59.000Z

    The Carbon Characterization Laboratory (CCL) is located in Labs C19 and C20 of the Idaho National Laboratory Research Center. The CCL was established under the Next Generation Nuclear Plant Project to support graphite and ceramic composite research and development activities. The research conducted in this laboratory will support the Advanced Graphite Creep experiments—a major series of material irradiation experiments within the Next Generation Nuclear Plant Graphite program. The CCL is designed to characterize and test low activated irradiated materials such as high purity graphite, carbon-carbon composites, silicon-carbide composite, and ceramic materials. The laboratory is fully capable of characterizing material properties for both irradiated and nonirradiated materials. Major infrastructural modifications were undertaken to support this new radiological facility at Idaho National Laboratory. Facility modifications are complete, equipment has been installed, radiological controls and operating procedures have been established and work management documents have been created to place the CCL in readiness to receive irradiated graphite samples.

  12. Irradiation Stability of Carbon Nanotubes and Related Materials

    E-Print Network [OSTI]

    Aitkaliyeva, Assel 1985-

    2012-09-28T23:59:59.000Z

    Application of carbon nanotubes (CNTs) in various fields demands a thorough investigation of their stability under irradiation. Open structure, ability to reorganize and heal defects, and large surface-to-volume ratio of carbon nanotubes affect...

  13. Irradiation facilities at the Los Alamos Meson Physics Facility

    SciTech Connect (OSTI)

    Sandberg, V.

    1990-01-01T23:59:59.000Z

    The irradiation facilities for testing SSC components and detector systems are described. Very high intensity proton, neutron, and pion fluxes are available with beam kinetic energies of up to 800 MeV. 4 refs., 12 figs., 2 tabs.

  14. agr-1 irradiation experiment: Topics by E-print Network

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

    E. Schwartz Department Direct-normal solar irradiance (DNSI), the total energy in the solar spectrum incident in unit time Schwartz, Stephen E. 13 An Experiment at HiRadMat:...

  15. Post-irradiation Examination and Fission Product Inventory Analysis of AGR-1 Irradiation Capsules

    SciTech Connect (OSTI)

    J M Harp; P D Demkowicz; S A Ploger

    2012-10-01T23:59:59.000Z

    The AGR-1 experiment was the first in a series of Advanced Gas Reactor (AGR) experiments designed to test TRISO fuel under High Temperature Gas Reactor irradiation conditions. This experiment was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) and is currently undergoing post-irradiation examination (PIE) at INL’s Materials and Fuels Complex (MFC). The inventory and distribution of fission products, especially Ag-110m, was assessed and analyzed for all the components of the AGR-1 capsules. This data should help inform the study of fission product migration in coated particle fuel. Gamma spectrometry was used to measure the activity of various different fission products in the different components of the AGR-1 test train. Each capsule contained: 12 fuel compacts, a graphite holder that kept the fuel compacts in place, graphite spacers that were above and below the graphite holders and fuel compacts, gas lines through which a helium neon gas mixture flowed in and out of each capsule, and the stainless steel shell that contained the experiment. Gamma spectrometry results and the experimental techniques used to capture these results will be presented for all the capsule components. The components were assayed to determine the total activity of different fission products present in or on them. These totals are compared to the total expected activity of a particular fission product in the capsule based on predictions from physics simulation. Based on this metric, a significant fraction of the Ag-110m was detected outside the fuel compacts, but the amount varied highly between the 6 capsules. Very small fractions of Cs-137 (<2E-5), Cs-134 (<1e-5), and Eu-154 (<4e-4) were detected outside of the fuel compacts. Additionally, the distribution of select fission products in some of the components including the fuel compacts and the graphite holders were measured and will be discussed.

  16. Infrared Excess and Molecular Clouds: A comparison of new suerveys of far-infrared and H I 21-cm emission at high galactic latitudes

    E-Print Network [OSTI]

    William T. Reach; William F. Wall; Nils Odegard

    1998-04-14T23:59:59.000Z

    We have created a map of the large-scale infrared surface brightness in excess of that associated with the atomic interstellar medium, using region-by-region correlations between the far-infrared and 21-cm line surface brightness. Our study updates and extends a previous attempt with IRAS and Berkeley/Parkes H I surveys. The far-infrared observations used here are from DIRBE, which extends far-infrared wavelength coverage to 240 um, so that we are reliably sampling the emission of large, thermal-equilibrium grains that dominate the dust mass. The H I data are from the combined Leiden-Dwingeloo and Parkes 21-cm line surveys. Using the maps of excess infrared emission at 100, 140, and 240 um, we created an atlas and identified the coherent structures. These infrared excess clouds can be caused both by dust that is warmer than average, or by dust associated with gas other than the atomic interstellar medium. We find very few warm clouds, such as the H II region around Spica. The majority of the infrared excess clouds are colder than the average atomic interstellar medium. These clouds are peaks of column density, and their excess infrared emission is due to dust associated with molecular gas. We identify essentially all known high-latitude molecular clouds in the infrared excess maps, and further identify a sample of new clouds with similar infrared properties. The infrared excess was correlated with CO line brightness, allowing us to measure the ratio of N(H2)/W(CO) for high-latitude clouds. The atlas of infrared excess may be a useful guide to regions of relatively high column density, which might cause high extinction toward extragalactic objects at optical and ultraviolet wavelengths and confusion for cosmic infrared and microwave backgrounds.

  17. Recovery of germanium-68 from irradiated targets

    DOE Patents [OSTI]

    Phillips, Dennis R. (Los Alamos, NM); Jamriska, Sr., David J. (Los Alamos, NM); Hamilton, Virginia T. (Los Alamos, NM)

    1993-01-01T23:59:59.000Z

    A process for selective separation of germanium-68 from proton irradiated molybdenum targets is provided and includes dissolving the molybdenum target in a hydrogen peroxide solution to form a first ion-containing solution, contacting the first ion-containing solution with a cationic resin whereby ions selected from the group consisting of molybdenum, niobium, technetium, selenium, vanadium, arsenic, germanium, zirconium and rubidium remain in a second ion-containing solution while ions selected from the group consisting of rubidium, zinc, beryllium, cobalt, iron, manganese, chromium, strontium, yttrium and zirconium are selectively adsorbed by the first resin, adjusting the pH of the second ion-containing solution to within a range of from about 0.7 to about 3.0, adjusting the soluble metal halide concentration in the second ion-containing solution to a level adapted for subsequent separation of germanium, contacting the pH-adjusted, soluble metal halide-containing second ion-containing solution with a dextran-based material whereby germanium ions are separated by the dextran-based material, and recovering the germanium from the dextran-based material, preferably by distillation.

  18. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect (OSTI)

    Lu, Zheng; Faulkner, Roy G. [IPTME, Loughborough University, Loughborough, Leics (United Kingdom)

    2008-07-01T23:59:59.000Z

    The understanding of radiation-induced grain boundary segregation (RIS) has considerably improved over the past decade. New models have been introduced and much effort has been devoted to obtaining comprehensive information on segregation from the literature. Analytical techniques have also improved so that chemical analysis of layers 1 nm thick is almost routine. This invited paper will review the major methods used currently for RIS prediction: namely, Rate Theory, Inverse Kirkendall, and Solute Drag approaches. A summary is made of the available data on phosphorus RIS in reactor pressure vessel (RPV) steels. This will be discussed in the light of the predictions of the various models in an effort to show which models are the most reliable and easy to use for forecasting P segregation behaviour in steels. A consequence of RIS in RPV steels is a radiation induced shift in the ductile to brittle transition temperature (DBTT). It will be shown how it is possible to relate radiation-induced P segregation levels to DBTT shift. Examples of this exercise will be given for RPV steels and for ferritic steels being considered for first wall fusion applications. Cr RIS in high alloy stainless steels and associated irradiation-assisted stress corrosion cracking (IASCC) will be briefly discussed. (authors)

  19. Use of laser extensometer for mechanical test on irradiated materials

    SciTech Connect (OSTI)

    Brillaud, C.; Meylogan, T.; Salathe, P. [Electricite de France, Avoine (France)

    1996-12-31T23:59:59.000Z

    Techniques have been developed by EDF`s hot laboratory in Chinon for performing mechanical tests on irradiated materials. Some of these techniques aim to facilitate strain measurements, which are particularly difficult to perform on irradiated specimens at high temperatures or on subsize specimens. Recent progress has been driven by laser technology combined with software development. The use of this technique, which allows strain measurements without contact on the specimen, is described for tensile (especially on subsize specimens), fatigue and creep tests.

  20. USE OF SILICON CARBIDE MONITORS IN ATR IRRADIATION TESTING

    SciTech Connect (OSTI)

    K. L. Davis; B. Chase; T. Unruh; D. Knudson; J. L. Rempe

    2012-07-01T23:59:59.000Z

    In April 2007, the Department of Energy (DOE) designated the Advanced Test Reactor (ATR) a National Scientific User Facility (NSUF) to advance US leadership in nuclear science and technology. By attracting new users from universities, laboratories, and industry, the ATR will support basic and applied nuclear research and development and help address the nation's energy security needs. In support of this new program, the Idaho National Laboratory (INL) has developed in-house capabilities to fabricate, test, and qualify new and enhanced temperature sensors for irradiation testing. Although most efforts emphasize sensors capable of providing real-time data, selected tasks have been completed to enhance sensors provided in irradiation locations where instrumentation leads cannot be included, such as drop-in capsule and Hydraulic Shuttle Irradiation System (HSIS) or 'rabbit' locations. For example, silicon carbide (SiC) monitors are now available to detect peak irradiation temperatures between 200°C and 800°C. Using a resistance measurement approach, specialized equipment installed at INL's High Temperature Test Laboratory (HTTL) and specialized procedures were developed to ensure that accurate peak irradiation temperature measurements are inferred from SiC monitors irradiated at the ATR. Comparison examinations were completed by INL to demonstrate this capability, and several programs currently rely on SiC monitors for peak temperature detection. This paper discusses the use of SiC monitors at the ATR, the process used to evaluate them at the HTTL, and presents representative measurements taken using SiC monitors.

  1. Initiate test loop irradiations of ALSEP process solvent

    SciTech Connect (OSTI)

    Dean R. Peterman; Lonnie G. Olson; Rocklan G. McDowell

    2014-09-01T23:59:59.000Z

    This report describes the initial results of the study of the impacts of gamma radiolysis upon the efficacy of the ALSEP process and is written in completion of milestone M3FT-14IN030202. Initial irradiations, up to 100 kGy absorbed dose, of the extraction section of the ALSEP process have been completed. The organic solvent used for these experiments contained 0.05 M TODGA and 0.75 M HEH[EHP] dissolved in n-dodecane. The ALSEP solvent was irradiated while in contact with 3 M nitric acid and the solutions were sparged with compressed air in order to maintain aerated conditions. The irradiated phases were used for the determination of americium and europium distribution ratios as a function of absorbed dose for the extraction and stripping conditions. Analysis of the irradiated phases in order to determine solvent composition as a function of absorbed dose is ongoing. Unfortunately, the failure of analytical equipment necessary for the analysis of the irradiated samples has made the consistent interpretation of the analytical results difficult. Continuing work will include study of the impacts of gamma radiolysis upon the extraction of actinides and lanthanides by the ALSEP solvent and the stripping of the extracted metals from the loaded solvent. The irradiated aqueous and organic phases will be analyzed in order to determine the variation in concentration of solvent components with absorbed gamma dose. Where possible, radiolysis degradation product will be identified.

  2. BEAM TILTED CORRELATIONS Frank Vignola

    E-Print Network [OSTI]

    Oregon, University of

    from the modules, module temperature, ambient temperature, wind speed, incident solar radiation under standardized operation conditions (25 Celsius and 1000 watts/meter2 incident solar radiation and comprehensive solar radiation data. Specifically, these models were designed to use the National Solar Radiation

  3. EFFECTS OF GAMMA IRRADIATION ON EPDM ELASTOMERS (REVISION 1)

    SciTech Connect (OSTI)

    Clark, E.

    2013-09-13T23:59:59.000Z

    Two formulations of EPDM elastomer, one substituting a UV stabilizer for the normal antioxidant in this polymer, and the other the normal formulation, were synthesized and samples of each were exposed to gamma irradiation in initially pure deuterium gas to compare their radiation stability. Stainless steel containers having rupture disks were designed for this task. After 130 MRad dose of cobalt-60 radiation in the SRNL Gamma Irradiation Facility, a significant amount of gas was created by radiolysis; however the composition indicated by mass spectroscopy indicated an unexpected increase in the total amount deuterium in both formulations. The irradiated samples retained their ductility in a bend test. No change of sample weight, dimensions, or density was observed. No change of the glass transition temperature as measured by dynamic mechanical analysis was observed, and most of the other dynamic mechanical properties remained unchanged. There appeared to be an increase in the storage modulus of the irradiated samples containing the UV stabilizer above the glass transition, which may indicate hardening of the material by radiation damage. Revision 1 adds a comparison with results of a study of tritium exposed EPDM. The amount of gas produced by the gamma irradiation was found to be equivalent to about 280 days exposure to initially pure tritium gas at one atmosphere. The glass transition temperature of the tritium exposed EPDM rose about 10 ?C. over 280 days, while no glass transition temperature change was observed for gamma irradiated EPDM. This means that gamma irradiation in deuterium cannot be used as a surrogate for tritium exposure.

  4. AGR-2 IRRADIATION TEST FINAL AS-RUN REPORT

    SciTech Connect (OSTI)

    Blaise, Collin

    2014-07-01T23:59:59.000Z

    This document presents the as-run analysis of the AGR-2 irradiation experiment. AGR-2 is the second of the planned irradiations for the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. Funding for this program is provided by the U.S. Department of Energy as part of the Very High Temperature Reactor (VHTR) Technical Development Office (TDO) program. The objectives of the AGR-2 experiment are to: (a) Irradiate UCO (uranium oxycarbide) and UO2 (uranium dioxide) fuel produced in a large coater. Fuel attributes are based on results obtained from the AGR-1 test and other project activities. (b) Provide irradiated fuel samples for post-irradiation experiment (PIE) and safety testing. (c) Support the development of an understanding of the relationship between fuel fabrication processes, fuel product properties, and irradiation performance. The primary objective of the test was to irradiate both UCO and UO2 TRISO (tri-structural isotropic) fuel produced from prototypic scale equipment to obtain normal operation and accident condition fuel performance data. The UCO compacts were subjected to a range of burnups and temperatures typical of anticipated prismatic reactor service conditions in three capsules. The test train also includes compacts containing UO2 particles produced independently by the United States, South Africa, and France in three separate capsules. The range of burnups and temperatures in these capsules were typical of anticipated pebble bed reactor service conditions. The results discussed in this report pertain only to U.S. produced fuel. In order to achieve the test objectives, the AGR-2 experiment was irradiated in the B-12 position of the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) for a total irradiation duration of 559.2 effective full power days (EFPD). Irradiation began on June 22, 2010, and ended on October 16, 2013, spanning 12 ATR power cycles and approximately three and a half calendar years. The test contained six independently controlled and monitored capsules. Each U.S. capsule contained 12 compacts of either UCO or UO2 AGR coated fuel. No fuel particles failed during the AGR-2 irradiation. Final burnup values on a per compact basis ranged from 7.26 to 13.15% FIMA (fissions per initial heavy-metal atom) for UCO fuel, and 9.01 to 10.69% FIMA for UO2 fuel, while fast fluence values ranged from 1.94 to 3.47´1025 n/m2 (E >0.18 MeV) for UCO fuel, and from 3.05 to 3.53´1025 n/m2 (E >0.18 MeV) for UO2 fuel. Time-average volume-average (TAVA) temperatures on a capsule basis at the end of irradiation ranged from 987°C in Capsule 6 to 1296°C in Capsule 2 for UCO, and from 996 to 1062°C in UO2-fueled Capsule 3. By the end of the irradiation, all of the installed thermocouples (TCs) had failed. Fission product release-to-birth (R/B) ratios were quite low. In the UCO capsules, R/B values during the first three cycles were below 10-6 with the exception of the hotter Capsule 2, in which the R/Bs reached 2´10-6. In the UO2 capsule (Capsule 3), the R/B values during the first three cycles were below 10-7. R/B values for all following cycles are not reliable due to gas flow and cross talk issues.

  5. Electron beam irradiation of gemstone for color enhancement

    SciTech Connect (OSTI)

    Idris, Sarada; Ghazali, Zulkafli; Hashim, Siti A'iasah; Ahmad, Shamshad; Jusoh, Mohd Suhaimi [Malaysian Nuclear Agency, Bangi, Selangor (Malaysia); School of Chemicals and Material Engineering, NUST Islamabad (Pakistan); Malaysian Nuclear Agency, Bangi, Selangor (Malaysia)

    2012-09-26T23:59:59.000Z

    Numerous treatment of gemstones has been going on for hundreds of years for enhancing color and clarity of gems devoid of these attributes. Whereas previous practices included fraudulent or otherwise processes to achieve the color enhancement, the ionizing radiation has proven to be a reliable and reproducible technique. Three types of irradiation processes include exposure to gamma radiation, electron beam irradiation and the nuclear power plants. Electron Beam Irradiation of Gemstone is a technique in which a gemstone is exposed to highly ionizing radiation electron beam to knock off electrons to generate color centers culminating in introduction of deeper colors. The color centers may be stable or unstable. Below 9MeV, normally no radioactivity is introduced in the exposed gems. A study was conducted at Electron Beam Irradiation Centre (Alurtron) for gemstone color enhancement by using different kind of precious gemstones obtained from Pakistan. The study shows that EB irradiation not only enhances the color but can also improves the clarity of some type of gemstones. The treated stones included kunzite, tourmaline, topaz, quartz, aquamarine and cultured pearls. Doses ranging from 25 kGy to 200 KGy were employed to assess the influence of doses on color and clarity and to select the optimum doses. The samples used included both the natural and the faceted gemstones. It is concluded that significant revenue generation is associated with the enhancement of the color in clarity of gemstones which are available at very cheap price in the world market.

  6. Synthesis of nanosize BPO{sub 4} under microwave irradiation

    SciTech Connect (OSTI)

    Wang, Rui, E-mail: wr_wrwr@163.com [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China) [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China); School of Chemical Engineering, Dalian University of Technology, Dalian 116023 (China); Jiang, Heng; Gong, Hong; Zhang, Jun [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China)] [School of Chemistry and Materials Science, Liaoning Shihua University, Fushun 113001 (China)

    2012-08-15T23:59:59.000Z

    Highlights: ? Nanosize BPO{sub 4} are prepared under microwave-irradiation conditions. ? This reaction is only performed at less than 640 W power for 2.5–5 min. ? The particles of sample irradiated at 400 W are 40–90 nm in size and well dispersed. ? A simple, fast and green procedure for synthesis of nanosize BPO{sub 4} is developed. -- Abstract: Nanosize BPO{sub 4} was synthesized using H{sub 3}BO{sub 3} and H{sub 3}PO{sub 4} (85%) as raw materials under microwave irradiation. This reaction was performed at powers lower than 640 W and irradiation time ranging from 2.5 min to 5 min, which were only a fraction of the time required for conventional synthetic procedures. The structure of the as-prepared BPO{sub 4} is analogous to that of a high cristobalite. The particle sizes of the samples irradiated at 640 and 400 W range from 40 nm to 90 nm and 30 nm to 60 nm, respectively. The effects of different conditions on the experimental outcome are also discussed.

  7. Tilt generation in step-graded In{sub x}Ga{sub 1-x}As metamorphic pseudosubstrate on a singular GaAs substrate using a low-temperature grown InGaP interlayer

    SciTech Connect (OSTI)

    Ghanad Tavakoli, Shahram; Hulko, Oksana; Thompson, David A. [Department of Engineering Physics, 1280 Main Street West, Hamilton, Ontario L8S 4 L7 (Canada)

    2008-05-15T23:59:59.000Z

    Metamorphic pseudosubstrates of In{sub 0.42}Ga{sub 0.58}As were grown by molecular beam epitaxy using step-graded In{sub x}Ga{sub 1-x}As buffer layers grown either directly on a (001) GaAs substrate or on a GaAs substrate overgrown with a layer of low-temperature grown In{sub 0.51}Ga{sub 0.49}P (LT-InGaP). The structures were examined using x-ray reciprocal space mapping to determine the characteristics of the pseudosubstrates and buffer layers. For the sample grown on the LT-InGaP layer, the pseudosubstrate exhibited an asymmetric tilt around [110] toward the [110] direction. Weak-beam dark-field electron imaging shows an imbalance of misfit dislocations with opposite sign Burgers vector. An explanation for this tilt is given and it is suggested that it may be responsible for the improved quality of epitaxial layers grown on such pseudosubstrates.

  8. Dose calculation methodology for irradiation treatment of complex-shaped foods

    E-Print Network [OSTI]

    Kim, Jongsoon

    2009-06-02T23:59:59.000Z

    of apple phantom, tilting and axial rotation ensures dose distribution of the entire surface of the phantom, even reaching the critical regions of the apple stem and calyx ends. For 1 and 5 MeV X-ray simulations, both depth-dose curves show exponential...

  9. Neutron and gamma irradiation damage to organic materials.

    SciTech Connect (OSTI)

    White, Gregory Von, II; Bernstein, Robert

    2012-04-01T23:59:59.000Z

    This document discusses open literature reports which investigate the damage effects of neutron and gamma irradiation on polymers and/or epoxies - damage refers to reduced physical chemical, and electrical properties. Based on the literature, correlations are made for an SNL developed epoxy (Epon 828-1031/DDS) with an expected total fast-neutron fluence of {approx}10{sup 12} n/cm{sup 2} and a {gamma} dosage of {approx}500 Gy received over {approx}30 years at < 200 C. In short, there are no gamma and neutron irradiation concerns for Epon 828-1031/DDS. To enhance the fidelity of our hypotheses, in regards to radiation damage, we propose future work consisting of simultaneous thermal/irradiation (neutron and gamma) experiments that will help elucidate any damage concerns at these specified environmental conditions.

  10. On the Absorption and Redistribution of Energy in Irradiated Planets

    E-Print Network [OSTI]

    Hansen, Brad

    2008-01-01T23:59:59.000Z

    We present a sequence of toy models for irradiated planet atmospheres, in which the effects of geometry and energy redistribution are modelled self-consistently. We use separate but coupled grey atmosphere models to treat the ingoing stellar irradiation and outgoing planetary reradiation. We investigate how observed quantities such as full phase secondary eclipses and orbital phase curves depend on various important parameters, such as the depth at which irradiation is absorbed and the depth at which energy is redistributed. We also compare our results to the more detailed radiative transfer models in the literature, in order to understand how those map onto the toy model parameter space. Such an approach can prove complementary to more detailed calculations, in that they demonstrate, in a simple way, how the solutions change depending on where, and how, energy redistribution occurs. As an example of the value of such models, we demonstrate how energy redistribution and temperature equilibration at moderate o...

  11. Threshold irradiation dose for amorphization of silicon carbide

    SciTech Connect (OSTI)

    Snead, L.L.; Zinkle, S.J.

    1997-03-01T23:59:59.000Z

    The amorphization of silicon carbide due to ion and electron irradiation is reviewed with emphasis on the temperature-dependent critical dose for amorphization. The effect of ion mass and energy on the threshold dose for amorphization is summarized, showing only a weak dependence near room temperature. Results are presented for 0.56 MeV silicon ions implanted into single crystal 6H-SiC as a function of temperature and ion dose. From this, the critical dose for amorphization is found as a function of temperature at depths well separated from the implanted ion region. Results are compared with published data generated using electrons and xenon ions as the irradiating species. High resolution TEM analysis is presented for the Si ion series showing the evolution of elongated amorphous islands oriented such that their major axis is parallel to the free surface. This suggests that surface or strain effects may be influencing the apparent amorphization threshold. Finally, a model for the temperature threshold for amorphization is described using the Si ion irradiation flux and the fitted interstitial migration energy which was found to be {approximately}0.56eV. This model successfully explains the difference in the temperature dependent amorphization behavior of SiC irradiated with 0.56 MeV Si{sup +} at 1 x 10{sup -3} dpa/s and with fission neutrons irradiated at 1 x 10{sup -6} dpa/s irradiated to 15 dpa in the temperature range of {approximately}340{+-}10K.

  12. Irradiated Microsphere Gamma Analyzer for Examination of Particle Fuel

    SciTech Connect (OSTI)

    Paul A. Demkowicz; Various

    2014-06-01T23:59:59.000Z

    Fabrication of the first series of fuel compacts for the current US tristructural isotropic (TRISO) coated particle fuel development and qualification effort was completed at Oak Ridge National Laboratory (ORNL) in 2006. In November of 2009, after almost 3 years and 620 effective full power days of irradiation in the Advanced Test Reactor at Idaho National Laboratory (INL), the first Advanced Gas Reactor irradiation test (AGR-1) was concluded. Compacts were irradiated at a calculated timeaveraged, volume-averaged temperature of 955–1136°C to a burnup ranging from 11.2–19.5% fissions per initial metal atom and a total fast fluence of 2.2–4.3·1025 n/m2 [1]. No indication of fission product release from TRISO coating failure was observed during the irradiation test, based on real-time monitoring of gaseous fission products. Post-irradiation examination (PIE) and hightemperature safety testing of the compacts has been in progress at both ORNL and INL since 2010, and have revealed small releases of a limited subset of fission products (such as silver, cesium, and europium). Past experience has shown that some elements can be released from TRISO particles when a defect forms in the SiC layer, even when one or more pyrocarbon layers remain intact and retain the gaseous fission products. Some volatile elements can also be released by diffusion through an intact SiC layer during safety testing if temperatures are high enough and the duration is long enough. In order to understand and quantify the release of certain radioactive fission products, it is sometimes necessary to individually examine each of the more than 4000 coated particles in a given compact. The Advanced Irradiated Microsphere Gamma Analyzer (Advanced- IMGA) was designed to perform this task in a remote hot cell environment. This paper describes the Advanced- IMGA equipment and examination process and gives results for a typical full compact evaluation.

  13. Raman and AFM study of gamma irradiated plastic bottle sheets

    SciTech Connect (OSTI)

    Ali, Yasir; Kumar, Vijay; Dhaliwal, A. S. [Department of Physics, Sant Longowal Institute of Engineering and Technology Longowal, Punjab-148106 (India); Sonkawade, R. G. [School of Physical Sciences, Babasaheb Bhimrao Ambedkar University, Lucknow-226025 (India)

    2013-02-05T23:59:59.000Z

    In this investigation, the effects of gamma irradiation on the structural properties of plastic bottle sheet are studied. The Plastic sheets were exposed with 1.25MeV {sup 60}Co gamma rays source at various dose levels within the range from 0-670 kGy. The induced modifications were followed by micro-Raman and atomic force microscopy (AFM). The Raman spectrum shows the decrease in Raman intensity and formation of unsaturated bonds with an increase in the gamma dose. AFM image displays rough surface morphology after irradiation. The detailed Raman analysis of plastic bottle sheets is presented here, and the results are correlated with the AFM observations.

  14. Tensile Hoop Behavior of Irradiated Zircaloy-4 Nuclear Fuel Cladding

    SciTech Connect (OSTI)

    Jaramillo, Roger A [ORNL; Hendrich, WILLIAM R [ORNL; Packan, Nicolas H [ORNL

    2007-03-01T23:59:59.000Z

    A method for evaluating the room temperature ductility behavior of irradiated Zircaloy-4 nuclear fuel cladding has been developed and applied to evaluate tensile hoop strength of material irradiated to different levels. The test utilizes a polyurethane plug fitted within a tubular cladding specimen. A cylindrical punch is used to compress the plug axially, which generates a radial displacement that acts upon the inner diameter of the specimen. Position sensors track the radial displacement of the specimen outer diameter as the compression proceeds. These measurements coupled with ram force data provide a load-displacement characterization of the cladding response to internal pressurization. The development of this simple, cost-effective, highly reproducible test for evaluating tensile hoop strain as a function of internal pressure for irradiated specimens represents a significant advance in the mechanical characterization of irradiated cladding. In this project, nuclear fuel rod assemblies using Zircaloy-4 cladding and two types of mixed uranium-plutonium oxide (MOX) fuel pellets were irradiated to varying levels of burnup. Fuel pellets were manufactured with and without thermally induced gallium removal (TIGR) processing. Fuel pellets manufactured by both methods were contained in fuel rod assemblies and irradiated to burnup levels of 9, 21, 30, 40, and 50 GWd/MT. These levels of fuel burnup correspond to fast (E > 1 MeV) fluences of 0.27, 0.68, 0.98, 1.4 and 1.7 1021 neutrons/cm2, respectively. Following irradiation, fuel rod assemblies were disassembled; fuel pellets were removed from the cladding; and the inner diameter of cladding was cleaned to remove residue materials. Tensile hoop strength of this cladding material was tested using the newly developed method. Unirradiated Zircaloy-4 cladding was also tested. With the goal of determining the effect of the two fuel types and different neutron fluences on clad ductility, tensile hoop strength tests were performed on cladding for these varying conditions. Experimental data revealed negligible performance differences for cladding containing TIGR vs non-TIGR processed fuel pellets. Irradiation hardening was observed in tensile hoop data as the strength of the cladding increased with increasing neutron dose and appeared to saturate for a fast fluence of 1.7 1021 neutrons/cm2.

  15. HTS wire irradiation test with 8 GeV protons

    SciTech Connect (OSTI)

    S. Feher; H. Glass; Y. Huang; P.J. Limon; D.F. Orris; P. Schlabach; M.A. Tartaglia; J.C. Tompkins

    1999-11-02T23:59:59.000Z

    The radiation level at High Energy Particle Accelerators (HEPA) is relatively high. Any active component which should be close to the accelerator has to be radiation hard. Since High Temperature Superconductors (HTS) have a great potential to be used in HEPAs (e.g., in superconducting magnets, current leads, RF cavities), it is important to understand the radiation hardness of these materials. A radiation test of HTS wire (Bi-2223) was performed at Fermilab. The HTS sample was irradiated with 8 GeV protons and the relative I{sub c} was measured during the irradiation. The total radiation dose was 10 Mrad, and no I{sub c} degradation was observed.

  16. Thermal response of photovoltaic cell to laser beam irradiation

    E-Print Network [OSTI]

    Yuan, Yu-Chen

    2014-01-01T23:59:59.000Z

    This paper firstly presents the concept of using dual laser beam to irradiate the photovoltaic cell, so as to investigate the temperature dependency of the efficiency of long distance energy transmission. Next, the model on the multiple reflection and absorption of any monochromatic light in multilayer structure has been established, and the heat generation in photovoltaic cell has been interpreted in this work. Then, the finite element model has been set up to calculate the temperature of photovoltaic cell subjected to laser irradiation. Finally, the effect of temperature elevation on the efficiency and reliability of photovoltaic cell has been discussed to provide theoretical references for designing the light-electricity conversion system.

  17. Fission product release from irradiated LWR fuel under accident conditions

    SciTech Connect (OSTI)

    Strain, R.V.; Sanecki, J.E.; Osborne, M.F.

    1984-01-01T23:59:59.000Z

    Fission product release from irradiated LWR fuel is being studied by heating fuel rod segments in flowing steam and an inert carrier gas to simulate accident conditions. Fuels with a range of irradiation histories are being subjected to several steam flow rates over a wide range of temperatures. Fission product release during each test is measured by gamma spectroscopy and by detailed examination of the collection apparatus after the test has been completed. These release results are complemented by a detailed posttest examination of samples of the fuel rod segment. Results of release measurements and fuel rod characterizations for tests at 1400 through 2000/sup 0/C are presented in this paper.

  18. Enhanced electrochemical etching of ion irradiated silicon by localized amorphization

    SciTech Connect (OSTI)

    Dang, Z. Y.; Breese, M. B. H. [Centre for Ion Beam Applications (CIBA), Department of Physics, National University of Singapore Singapore 117542 (Singapore); Lin, Y.; Tok, E. S. [Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542 (Singapore); Vittone, E. [Physics Department, NIS Excellence Centre and CNISM, University of Torino, via Pietro Giuria 1, 10125 Torino (Italy)

    2014-05-12T23:59:59.000Z

    A tailored distribution of ion induced defects in p-type silicon allows subsequent electrochemical anodization to be modified in various ways. Here we describe how a low level of lattice amorphization induced by ion irradiation influences anodization. First, it superposes a chemical etching effect, which is observable at high fluences as a reduced height of a micromachined component. Second, at lower fluences, it greatly enhances electrochemical anodization by allowing a hole diffusion current to flow to the exposed surface. We present an anodization model, which explains all observed effects produced by light ions such as helium and heavy ions such as cesium over a wide range of fluences and irradiation geometries.

  19. Light water reactor mixed-oxide fuel irradiation experiment

    SciTech Connect (OSTI)

    Hodge, S.A.; Cowell, B.S. [Oak Ridge National Lab., TN (United States); Chang, G.S.; Ryskamp, J.M. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States). Idaho National Engineering and Environmental Lab.

    1998-06-01T23:59:59.000Z

    The United States Department of Energy Office of Fissile Materials Disposition is sponsoring and Oak Ridge National Laboratory (ORNL) is leading an irradiation experiment to test mixed uranium-plutonium oxide (MOX) fuel made from weapons-grade (WG) plutonium. In this multiyear program, sealed capsules containing MOX fuel pellets fabricated at Los Alamos National Laboratory (LANL) are being irradiated in the Advanced Test Reactor (ATR) at the Idaho National Engineering and Environmental Laboratory (INEEL). The planned experiments will investigate the utilization of dry-processed plutonium, the effects of WG plutonium isotopics on MOX performance, and any material interactions of gallium with Zircaloy cladding.

  20. Delayed neutrons from the neutron irradiation of ²³?U

    E-Print Network [OSTI]

    Heinrich, Aaron David

    2008-10-10T23:59:59.000Z

    transient control rod transit time from full insertion in the core to full extraction and the controlled power excursion itself all contribute to the inherent delay of the reactor pulse. When the reactor was operating at 300 watts the desired count time...) was redesigned to reduce a sample’s pneumatic flight time from over 1,600 milliseconds to less than 450 milliseconds. Four saturation irradiations were performed at reactor powers of 100 and 200 kW for 300 seconds and one burst irradiation was performed using...

  1. Impact of 15 Jan 2010 annular solar eclipse on the equatorial and low latitude ionosphere over Indian region from Magnetometer, Ionosonde and GPS observations

    E-Print Network [OSTI]

    Panda, Sampad Kumar; Rajaram, Girija; Sripathi, Samireddipalle; Bhaskar, Ankush

    2015-01-01T23:59:59.000Z

    The annular eclipse of Jan 15, 2010 over southern India was studied with a network of multi-instrumental observations consisting magnetometer, ionosonde and GPS receivers. By selecting the day before and the normal EEJ days as the control days, it is intrinsically proved that the regular eastward electric field for the whole day at the equator was not just weakened but actually was flipped for several hours by the influence of tides related to the spectacular Sun-Moon-Earth alignment near the middle of the day. The effect of flipping the electric field was clearly seen in the equatorial ionosonde data and through the large array of GPS receivers that accomplished the TEC data. The main impact of the change in the electric field was the reduced EIA at all latitudes, with the anomaly crest that shifted towards the equator. The equatorial F-region density profile was also showing an enhanced F region peak in spite of a reduced VTEC. By comparison to the plasma density depletion associated with the temporary lack...

  2. SLIGHTLY IRRADIATED FUEL (SIF) INTERIM DISPOSITION PROJECT

    SciTech Connect (OSTI)

    NORTON SH

    2010-02-23T23:59:59.000Z

    CH2M HILL Plateau Remediation Company (CH2M HILL PRC) is proud to submit the Slightly Irradiated Fuel (SIF) Interim Disposition Project for consideration by the Project Management Institute as Project of the Year for 2010. The SIF Project was a set of six interrelated sub-projects that delivered unique stand-alone outcomes, which, when integrated, provided a comprehensive and compliant system for storing high risk special nuclear materials. The scope of the six sub-projects included the design, construction, testing, and turnover of the facilities and equipment, which would provide safe, secure, and compliant Special Nuclear Material (SNM) storage capabilities for the SIF material. The project encompassed a broad range of activities, including the following: Five buildings/structures removed, relocated, or built; Two buildings renovated; Structural barriers, fencing, and heavy gates installed; New roadways and parking lots built; Multiple detection and assessment systems installed; New and expanded communication systems developed; Multimedia recording devices added; and A new control room to monitor all materials and systems built. Project challenges were numerous and included the following: An aggressive 17-month schedule to support the high-profile Plutonium Finishing Plant (PFP) decommissioning; Company/contractor changeovers that affected each and every project team member; Project requirements that continually evolved during design and construction due to the performance- and outcome-based nature ofthe security objectives; and Restrictions imposed on all communications due to the sensitive nature of the projects In spite of the significant challenges, the project was delivered on schedule and $2 million under budget, which became a special source of pride that bonded the team. For years, the SIF had been stored at the central Hanford PFP. Because of the weapons-grade piutonium produced and stored there, the PFP had some of the tightest security on the Hanford nuclear reservation. Workers had to pass through metal detectors when they arrived at the plant and materials leaving the plant had to be scanned for security reasons. Whereas other high-security nuclear materials were shipped from the PFP to Savannah River, S.C. as part ofa Department of Energy (DOE) program to consolidate weapons-grade plutonium, it was determined that the SIF should remain onsite pending disposition to a national repository. Nevertheless, the SIF still requires a high level of security that the PFP complex has always provided. With the 60-year PFP mission of producing and storing plutonium concluded, the environmental cleanup plans for Hanford call for the demolition of the 63-building PFP complex. Consequently, if the SIF remained at PFP it not only would have interfered with the environmental cleanup plans, but would have required $100 million in facility upgrades to meet increased national security requirements imposed after the 9/11 terrorist attacks. A new smaller and more cost-effective area was needed to store this material, which led to the SIF Project. Once the SIF project was successfully completed and the SIF was safely removed from PFP, the existing Protected Area at PFP could be removed, and demolition could proceed more quickly without being encumbered by restrictive security requirements that an active Protected Area requires. The lightened PFP security level brought by safely removing and storing the SIF would also yield lowered costs for deactivation and demolition, as well as reduce overall life-cycle costs.

  3. Electron Irradiation Induced Changes of the Electrical Transport Properties of Graphene 

    E-Print Network [OSTI]

    Woo, Sung Oh

    2014-08-06T23:59:59.000Z

    This research investigates the effect of electron irradiation on transport properties in graphene Field Effect Transistor (FET) devices. Upon irradiation, graphene is doped with electrons and adsorbs molecules by transfer of accumulated electrons...

  4. Ion irradiation of Fe-Fe oxide core-shell nanocluster films:...

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

    irradiation of Fe-Fe oxide core-shell nanocluster films: Effect of interface on stability of magnetic properties. Ion irradiation of Fe-Fe oxide core-shell nanocluster films:...

  5. Conjugated linoleic acid reduces lipid oxidation in irradiated, cooked ground beef patties 

    E-Print Network [OSTI]

    Chae, Sung Hee

    2007-09-17T23:59:59.000Z

    This study was conducted to examine the antioxidative effect of conjugated linoleic acid (CLA) in irradiated, cooked ground beef patties. The hypothesis was that CLA would be retained during irradiation and would reduce ...

  6. Conjugated linoleic acid reduces lipid oxidation in irradiated, cooked ground beef patties

    E-Print Network [OSTI]

    Chae, Sung Hee

    2007-09-17T23:59:59.000Z

    This study was conducted to examine the antioxidative effect of conjugated linoleic acid (CLA) in irradiated, cooked ground beef patties. The hypothesis was that CLA would be retained during irradiation and would reduce lipid oxidation...

  7. Electron Irradiation Induced Changes of the Electrical Transport Properties of Graphene

    E-Print Network [OSTI]

    Woo, Sung Oh

    2014-08-06T23:59:59.000Z

    This research investigates the effect of electron irradiation on transport properties in graphene Field Effect Transistor (FET) devices. Upon irradiation, graphene is doped with electrons and adsorbs molecules by transfer of accumulated electrons...

  8. Radiochemical Transformation of High Pressure Methane under Gamma, Electron, and Neutron Irradiation

    E-Print Network [OSTI]

    Clemens, Jeffrey Tyler

    2014-05-01T23:59:59.000Z

    The chemical effects of irradiation on high pressure methane and noble gas mixtures were investigated using gamma, electron beam, and neutron irradiation sources. The gamma source used was the La-140 source from the Nuclear Science Center (NSC...

  9. Etch-free Formation of Porous Silicon by High-energy Ion Irradiation...

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

    Etch-free Formation of Porous Silicon by High-energy Ion Irradiation. Etch-free Formation of Porous Silicon by High-energy Ion Irradiation. Abstract: In this study, porous silicon...

  10. Microstructural changes induced by low energy heavy ion irradiation in titanium silicon carbide

    E-Print Network [OSTI]

    Boyer, Edmond

    Microstructural changes induced by low energy heavy ion irradiation in titanium silicon carbide CNRS 6622, Parc Valrose, 06108 Nice cedex 2, France ABSTRACT Low energy ion irradiation was used

  11. Amorphization Processes in Au Ion Irradiated GaN at 150 - 300...

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

    Processes in Au Ion Irradiated GaN at 150 - 300 K. Amorphization Processes in Au Ion Irradiated GaN at 150 - 300 K. Abstract: Epitaxial single-crystal gallium nitride (GaN) films...

  12. Thermal evolution of microstructure in ion-irradiated GaN. |...

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

    evolution of microstructure in ion-irradiated GaN. Thermal evolution of microstructure in ion-irradiated GaN. Abstract: The thermal evolution of the microstructure created by...

  13. Damage and Microstructure Evolution in GaN under Au Ion Irradiation...

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

    and Microstructure Evolution in GaN under Au Ion Irradiation. Damage and Microstructure Evolution in GaN under Au Ion Irradiation. Abstract: Damage and microstructure evolution in...

  14. Irradiation Testing of Blanket Materials at the HFR Petten with On Line Tritium Monitoring

    SciTech Connect (OSTI)

    Magielsen, A.J.; Laan, J.G. van der; Hegeman, J.B.J.; Stijkel, M.P.; Ooijevaar, M.A.G

    2005-07-15T23:59:59.000Z

    Irradiation experiments are performed in support of fusion blanket technology development. These comprise ceramic solid breeder materials, and a liquid Lithium Lead alloy, as well as blanket subassemblies and components. Experimental facilities at the HFR to study tritium release, permeation characteristics, and neutron irradiation performance, have recently been extended. This paper gives an overview on the tritium breeding materials irradiation programme and describes the facilities required for irradiation testing and on-line tritium measurement.

  15. RIS-M-2352 DETERMINATION OF RETAINED GAS IN IRRADIATED FUEL SAMPLES

    E-Print Network [OSTI]

    -IRRADIATION EXAMINATION; RADIATION CHEMISTRY; SPENT FUELS; URANIUM DIOXIDE; XENON; XENON ISOTOPES UDC 621.039.548 ISBN 87

  16. E-Print Network 3.0 - assembly duct irradiated Sample Search...

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

    Laboratory, Environmental Energy Technologies Division, Energy Performance of Buildings Group Collection: Energy Storage, Conversion and Utilization 3 POST-IRRADIATION...

  17. Proton Irradiation Damage Assessment of Carbon Reinforced Composites

    E-Print Network [OSTI]

    McDonald, Kirk

    Proton Irradiation Damage Assessment of Carbon Reinforced Composites: 2-D & 3-D Weaved Structures carbon-carbon composite ATJ Graphite 3D CC composite AGS Beam-on-Target tests show clearly that carbon composites are better absorbers of thermo- mechanical shock. This is attributed to the very low coeff

  18. RETHINKING SATELLITE BASED SOLAR IRRADIANCE MODELLING R. W. Mueller

    E-Print Network [OSTI]

    Heinemann, Detlev

    -German Aerospace Center; 5-Ecole des Mines de Paris ABSTRACT Accurate solar irradiance data are not only necessary for an efficient planning and operation of solar energy systems. Within the European project of the climate system, but also absolutely necessary for an efficient planning and operation of solar energy

  19. Vacuum aperture isolator for retroreflection from laser-irradiated target

    DOE Patents [OSTI]

    Benjamin, Robert F. (Los Alamos, NM); Mitchell, Kenneth B. (Los Alamos, NM)

    1980-01-01T23:59:59.000Z

    The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.

  20. Development of a chemical dosimeter for electron beam food irradiation

    E-Print Network [OSTI]

    Rivadeneira, Ramiro Geovanny

    2006-08-16T23:59:59.000Z

    uniform irradiation treatment on apple-phantoms (a complex shaped target) and GAFCHROMIC® HD-810 films using electron beams from (1) a 2 MeV Van de Graaff (VDG) accelerator, (2) a 10 MeV Linear Accelerator (LINAC), and (3) X-rays from a 5 MeV LINAC...

  1. Spectral solar irradiance before and during a Harmattan dust spell

    SciTech Connect (OSTI)

    Adeyefa, Z.D. [Federal Univ. of Technology, Akure (Nigeria)] [Federal Univ. of Technology, Akure (Nigeria); Holmgren, B. [Uppsala Univ. (Sweden)] [Uppsala Univ. (Sweden)

    1996-09-01T23:59:59.000Z

    Measurements of the ground-level spectral distributions of the direct, diffuse and global solar irradiance between 300 and 1100 nm were made at Akure (7.15{degree}N, 5.5{degree}E), Nigeria, in December 1991 before and during a Harmattan dust spell employing a spectroradiometer (LICOR LI-1800) with 6 nm resolution. The direct spectral solar irradiance which was initially reduced before the dust storm was further attenuated by about 50% after the spell. Estimated values of the Angstrom turbidity coefficient {beta} indicated an increase of about 146% of this parameter while the Angstrom wavelength-exponent {alpha} decreased by about 65% within the 2-day study period. The spectral diffuse-to-direct and diffuse-to-global ratios suggest that the main cause of the significant reduction in solar irradiance at the surface was the scattering by the aerosol which led to an increase in the diffuse component. The global irradiance though reduced, was less sensitive to changing Harmattan conditions. It is recommended that solar energy devices that use radiation from Sun and sky be used under fluctuating Harmattan conditions. There are some deviations from the Angstrom formula under very turbid Harmattan conditions which could be explained by the relative increase of the particle sizes. 31 refs., 12 figs., 3 tabs.

  2. adt materials irradiated: Topics by E-print Network

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

    adt materials irradiated First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Umsetzung von ADTs ADT in...

  3. Compressive Strength of Gamma-Irradiated Polymer Concrete

    E-Print Network [OSTI]

    North Texas, University of

    Compressive Strength of Gamma-Irradiated Polymer Concrete Gonzalo Marti´nez-Barrera,1,2 Uriel concrete (PC) was developed by using differ- ent concentrations of silica sand as aggregate of Plastics Engineers INTRODUCTION Polymer concrete (PC) is a particulate composite where thermoset resins

  4. SURVEILLANCE OF PHOTOVOLTAIC SOLAR ENERGY SYSTEMS USING METEOSAT DERIVED IRRADIANCES

    E-Print Network [OSTI]

    Heinemann, Detlev

    SURVEILLANCE OF PHOTOVOLTAIC SOLAR ENERGY SYSTEMS USING METEOSAT DERIVED IRRADIANCES Annette Hammer.Heinemann@uni-oldenburg.de 2Enecolo AG, Lindhof 235, CH-8617 M¨onchaltorf 3Fraunhofer Insitute for Solar Energy Systems Wiemken3, Hans Georg Beyer4, Vincent van Dijk5, Jethro Betcke5 1Dept. of Energy and Semiconductor Research

  5. SOLAR IRRADIANCE FORECASTING FOR THE MANAGEMENT OF SOLAR ENERGY SYSTEMS

    E-Print Network [OSTI]

    Heinemann, Detlev

    SOLAR IRRADIANCE FORECASTING FOR THE MANAGEMENT OF SOLAR ENERGY SYSTEMS Detlev Heinemann Oldenburg.girodo@uni-oldenburg.de ABSTRACT Solar energy is expected to contribute major shares of the future global energy supply. Due to its and solar energy conversion processes has to account for this behaviour in respective operating strategies

  6. The modelling of irradiation embrittlement in submerged-arc welds

    SciTech Connect (OSTI)

    Bolton, C.J.; Buswell, J.T.; Jones, R.B.; Moskovic, R.; Priest, R.H. [Nuclear Electric plc, Berkeley (United Kingdom). Berkeley Technology Centre

    1996-12-31T23:59:59.000Z

    Until very recently, the irradiation embrittlement behavior of submerged-arc welds has been interpreted in terms of two mechanisms, namely a matrix damage component and an additional component due to the irradiation-enhanced production of copper-rich precipitates. However, some of the weld specimens from a recent accelerated re-irradiation experiment have shown high Charpy shifts which exceeded the values expected from the measured shift in yield stress. Microstructural examination has revealed the occurrence of intergranular fracture (IGF) in these specimens, accompanied by grain boundary segregation of phosphorus. Theoretical models were developed to predict the parametric dependence of irradiation-enhanced phosphorus segregation on experimental variables. Using these parametric forms, along with the concept of a critical level of segregation for the onset of IGF instead of cleavage, a three mechanism trend curve has been developed. The form of this trend curve, taking into account IGF as well as matrix and copper embrittlement, is thus mechanistically based. The constants in the equation, however, are obtained by a statistical fit to the actual Charpy shift database.

  7. Post Irradiation Capabilities at the Idaho National Laboratory

    SciTech Connect (OSTI)

    Schulthess, J.L.

    2011-08-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) oversees the research, development, and demonstration activities that ensure nuclear energy remains a viable energy option for the United States. Fuel and material development through fabrication, irradiation, and characterization play a significant role in accomplishing the research needed to support nuclear energy. All fuel and material development requires the understanding of irradiation effects on the fuel performance and relies on irradiation experiments ranging from tests aimed at targeted scientific questions to integral effects under representative and prototypic conditions. The DOE recently emphasized a solution-driven, goal-oriented, science-based approach to nuclear energy development. Nuclear power systems and materials were initially developed during the latter half of the 20th century and greatly facilitated by the United States ability and willingness to conduct large-scale experiments. Fifty-two research and test reactors with associated facilities for performing fabrication and pre and post irradiation examinations were constructed at what is now Idaho National Laboratory (INL), another 14 at Oak Ridge National Laboratory (ORNL), and a few more at other national laboratory sites. Building on the scientific advances of the last several decades, our understanding of fundamental nuclear science, improvements in computational platforms, and other tools now enable technological advancements with less reliance on large-scale experimentation.

  8. Post Irradiation Capabilities at the Idaho National Laboratory

    SciTech Connect (OSTI)

    Schulthess, J.L.; Robert D. Mariani; Rory Kennedy; Doug Toomer

    2011-08-01T23:59:59.000Z

    The U.S. Department of Energy (DOE) Office of Nuclear Energy (NE) oversees the research, development, and demonstration activities that ensure nuclear energy remains a viable energy option for the United States. Fuel and material development through fabrication, irradiation, and characterization play a significant role in accomplishing the research needed to support nuclear energy. All fuel and material development requires the understanding of irradiation effects on the fuel performance and relies on irradiation experiments ranging from tests aimed at targeted scientific questions to integral effects under representative and prototypic conditions. The DOE recently emphasized a solution-driven, goal-oriented, science-based approach to nuclear energy development. Nuclear power systems and materials were initially developed during the latter half of the 20th century and greatly facilitated by the United States’ ability and willingness to conduct large-scale experiments. Fifty-two research and test reactors with associated facilities for performing fabrication and pre and post irradiation examinations were constructed at what is now Idaho National Laboratory (INL), another 14 at Oak Ridge National Laboratory (ORNL), and a few more at other national laboratory sites. Building on the scientific advances of the last several decades, our understanding of fundamental nuclear science, improvements in computational platforms, and other tools now enable technological advancements with less reliance on large-scale experimentation.

  9. Simultaneous Irradiation and Imaging of Blood Vessels During Pulsed

    E-Print Network [OSTI]

    Barton, Jennifer K.

    energy produced hemorrhage. In larger vessels, coagula often were attached to the superficial vessel wall; port wine stains INTRODUCTION Previous studies examining the effect of la- ser irradiation on cutaneous preparation. The short pulse duration illus- trated an extreme; energy was deposited quickly Contract grant

  10. Lymphocyte depletion in peripheral blood of gamma irradiated rats

    E-Print Network [OSTI]

    Goldin, Eric Michael

    1972-01-01T23:59:59.000Z

    38. F. H. Hager, A study of the effect of partial-body irradiation on the early reduction of circulating lymphocytes. (Thesis) Texas AKM University, 1969. 39. G. D'Angelo and M. Lacombe, A practical diluent for electz onic white cell counts. Amer...

  11. The AGR-1 Irradiation -Objectives, Success Criteria and Risk Management

    SciTech Connect (OSTI)

    James Kendall

    2006-06-01T23:59:59.000Z

    The AGR-1 experiment being conducted by the US Department of Energy Advanced Gas Reactor Fuel Development and Qualification Program (AGR fuel program) will irradiate TRISO-coated particle fuel in compacts under conditions representative of a Very High Temperature Reactor (VHTR) core. The anticipated fuel performance requirements of a prismatic core VHTR significantly exceed established TRISO-coated particle fuel capability in terms of burnup, temperature and fast fluence. AGR-1 is the first in a planned series of eight irradiations leading to the qualification of low enriched uranium coated particle fuel compacts for service in a VHTR, as identified in an overall Technical Program Plan produced at the beginning of the program . The AGR-1 experiment is scheduled for insertion in the Advanced Test Reactor (ATR) in the first quarter of fiscal year 2007 and to be irradiated for a period of up to approximately two and a half years. The irradiation rig, designated a "test train" is designed to provide six independently controlled (for temperature) and monitored (for fission product gas release) capsules containing fuel samples.

  12. atomic hydrogen irradiation: Topics by E-print Network

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

    hydrogen irradiation First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Synergistic Formation of Radicals...

  13. Dose characterization of the rad source 2400 x-ray irradiator

    E-Print Network [OSTI]

    Wagner, Jennifer Ann Koop

    2009-05-15T23:59:59.000Z

    The RS 2400 irradiator has been looked to as a replacement for discontinued gamma irradiators. The RS 2400 has a cylindrical, rather than point, x-ray source, which yields higher dose rates. The irradiator unit allows the user to set the current...

  14. Evaluating Quality and Palatability Characteristics of Beef Subprimals Treated with Low-dose Irradiation

    E-Print Network [OSTI]

    Arnold, John

    2012-02-14T23:59:59.000Z

    . Paired subprimals were randomly assigned to treated (irradiated) and control (non-irradiated) groups. The treated group was irradiated with a surface dose of 1-1.5 kGy. Following treatment, subprimals were fabricated into thirds and randomly assigned...

  15. Total Solar Irradiance Calibration Transfer Experiment/TIM Frequently Asked Questions

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    (TIM) measures the Sun's net energy output, or total solar irradiance (TSI). TSI is the spatially NASA/NOAA mission that will measure total solar irradiance to monitor changes in incident solar energy measurements of total solar irradiance to monitor changes in solar energy driving Earth's climate system

  16. Capillary Electrophoresis Separation of Protein Composition of c-Irradiated Food Pathogens Listeria

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Capillary Electrophoresis Separation of Protein Composition of c-Irradiated Food Pathogens Listeria proteins expression which may be related to the resistance or sensitivity of food pathogens to c-irradiation Composition of c-Irradiated Food Pathogens Listeria monocytogenes and Staphylococcus aureus. PLoS ONE 7(3): e

  17. A new, lower value of total solar irradiance: Evidence and climate significance

    E-Print Network [OSTI]

    data. TIM's lower solar irradiance value is not a change in the Sun's output, whose variationsA new, lower value of total solar irradiance: Evidence and climate significance Greg Kopp1 14 January 2011. [1] The most accurate value of total solar irradiance during the 2008 solar minimum

  18. Irradiation performance of AGR-1 high temperature reactor fuel

    SciTech Connect (OSTI)

    Paul A. Demkowicz; John D. Hunn; Robert N. Morris; Charles A. Baldwin; Philip L. Winston; Jason M. Harp; Scott A. Ploger; Tyler Gerczak; Isabella J. van Rooyen; Fred C. Montgomery; Chinthaka M. Silva

    2014-10-01T23:59:59.000Z

    The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO-coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.5% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel–including the extent of fission product release and the evolution of kernel and coating microstructures–was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of 110mAg from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocrabon and compact matrix. The capsule-average fractional release from the compacts was 1×10 4 to 5×10 4 for 154Eu and 8×10 7 to 3×10 5 for 90Sr. The average 134Cs release from compacts was <3×10 6 when all particles maintained intact SiC. An estimated four particles out of 2.98×105 experienced partial cesium release due to SiC failure during the irradiation, driving 134Cs release in two capsules to approximately 10 5. Identification and characterization of these particles has provided unprecedented insight into the nature and causes of SiC coating failure in high-quality TRISO fuel. In general, changes in coating morphology were found to be dominated by the behavior of the buffer and inner pyrolytic carbon (IPyC), and infrequently observed SiC layer damage was usually related to cracks in the IPyC. Palladium attack of the SiC layer was relatively minor, except for the particles that released cesium during irradiation, where SiC corrosion was found adjacent to IPyC cracks. Palladium, silver, and uranium were found in the SiC layer of irradiated particles, and characterization of these elements within the SiC microstructure is the subject of ongoing focused study.

  19. Irradiation effect on deuterium behaviour in low-dose HFIR neutron-irradiated tungsten

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

    Shimada, Masashi; Cao, G.; Otsuka, T.; Hara, M.; Kobayashi, M.; Oya, Y.; Hatano, Y.

    2015-01-01T23:59:59.000Z

    Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory at reactor coolant temperatures of 50–70 ?C to low displacement damage of 0.025 and 0.3 dpa. After cooling down, the HFIR neutronirradiated tungsten samples were exposed to deuterium plasmas in the Tritium Plasma Experiment, Idaho National Laboratory at 100, 200 and 500 ?C twice at the ion fluence of 5×1025 m-2 to reach the total ion fluence of 1×1026 m-2 in order to investigate maximum near-surface (more »in 0.3 dpa samples. The large discrepancy between the total retention via thermal desorption spectroscopy and the nearsurface retention via nuclear reaction analysis indicated the deuterium was trapped in bulk (at least 50µm depth for 0.025 dpa and 35µm depth for 0.3 dpa) at 500 ?C cases even in the relatively low ion fluence of 1026 m-2.« less

  20. Irradiation effect on deuterium behaviour in low-dose HFIR neutron-irradiated tungsten

    SciTech Connect (OSTI)

    Shimada, Masashi [Idaho National Lab. (INL), Idaho Falls, ID (United States).Fusion Safety Program; Cao, G. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics; Otsuka, T. [Kyushu Univ., Fukuoka (Japan). Interdisciplinary Graduate School of Engineering Science; Hara, M. [Univ. of Toyama (Japan). Hydrogen Isotope Center; Kobayashi, M. [Shizuoka Univ. (Japan). Radioscience Research Lab.; Oya, Y. [Shizuoka Univ. (Japan). Radioscience Research Lab.; Hatano, Y. [Shizuoka Univ. (Japan). Radioscience Research Lab.

    2015-01-01T23:59:59.000Z

    Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor (HFIR), Oak Ridge National Laboratory at reactor coolant temperatures of 50–70 ?C to low displacement damage of 0.025 and 0.3 dpa. After cooling down, the HFIR neutronirradiated tungsten samples were exposed to deuterium plasmas in the Tritium Plasma Experiment, Idaho National Laboratory at 100, 200 and 500 ?C twice at the ion fluence of 5×1025 m-2 to reach the total ion fluence of 1×1026 m-2 in order to investigate maximum near-surface (<5µm depth) deuterium concentration increased from 0.5 at% D/W in 0.025 dpa samples to 0.8 at% D/W in 0.3 dpa samples. The large discrepancy between the total retention via thermal desorption spectroscopy and the nearsurface retention via nuclear reaction analysis indicated the deuterium was trapped in bulk (at least 50µm depth for 0.025 dpa and 35µm depth for 0.3 dpa) at 500 ?C cases even in the relatively low ion fluence of 1026 m-2.

  1. Microscopic analysis of irradiated AGR-1 coated particle fuel compacts

    SciTech Connect (OSTI)

    Scott Ploger; Paul Demkowicz; John Hunn; Robert Morris

    2012-10-01T23:59:59.000Z

    The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak burnup of 19.5% FIMA with no in-pile failures observed out of 3×105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Five compacts have been examined so far, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose between approximately 40-80 individual particles on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer-IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, over 800 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in approximately 23% of the particles, and these fractures often resulted in unconstrained kernel swelling into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer-IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only three particles, all in conjunction with IPyC-SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures, IPyC-SiC debonds, and SiC fractures.

  2. Microscopic analysis of irradiated AGR-1 coated particle fuel compacts

    SciTech Connect (OSTI)

    Scott A. Ploger; Paul A. Demkowicz; John D. Hunn; Jay S. Kehn

    2014-05-01T23:59:59.000Z

    The AGR-1 experiment involved irradiation of 72 TRISO-coated particle fuel compacts to a peak compact-average burnup of 19.5% FIMA with no in-pile failures observed out of 3 x 105 total particles. Irradiated AGR-1 fuel compacts have been cross-sectioned and analyzed with optical microscopy to characterize kernel, buffer, and coating behavior. Six compacts have been examined, spanning a range of irradiation conditions (burnup, fast fluence, and irradiation temperature) and including all four TRISO coating variations irradiated in the AGR-1 experiment. The cylindrical specimens were sectioned both transversely and longitudinally, then polished to expose from 36 to 79 individual particles near midplane on each mount. The analysis focused primarily on kernel swelling and porosity, buffer densification and fracturing, buffer–IPyC debonding, and fractures in the IPyC and SiC layers. Characteristic morphologies have been identified, 981 particles have been classified, and spatial distributions of particle types have been mapped. No significant spatial patterns were discovered in these cross sections. However, some trends were found between morphological types and certain behavioral aspects. Buffer fractures were found in 23% of the particles, and these fractures often resulted in unconstrained kernel protrusion into the open cavities. Fractured buffers and buffers that stayed bonded to IPyC layers appear related to larger pore size in kernels. Buffer–IPyC interface integrity evidently factored into initiation of rare IPyC fractures. Fractures through part of the SiC layer were found in only four classified particles, all in conjunction with IPyC–SiC debonding. Compiled results suggest that the deliberate coating fabrication variations influenced the frequencies of IPyC fractures and IPyC–SiC debonds.

  3. Irradiation hardening and loss of ductility of type 316L(N) stainless steel plate material due to neutron-irradiation

    SciTech Connect (OSTI)

    Horsten, M.G.; Vries, M.I. de [Netherlands Energy Research Foundation, Petten (Netherlands)

    1996-12-31T23:59:59.000Z

    Type 316 stainless steel is the primary candidate austenitic structural material for fusion first wall constructions. Here, type 316L(N) stainless steel plate material has been irradiated up to 10 dpa at temperatures of 80, 225, 325, and 425 C in the High Flux Reactor (HFR) of Petten. Tensile tests have been performed in the temperature range from RT to 575 C at a conventional strain rate of 5 {times} 10{sup {minus}4} s{sup {minus}1}. The results of the tensile tests are analyzed in terms of irradiation hardening and loss of ductility due to irradiation. Tensile properties saturate in the early stage (within 0.65 dpa) at the lowest applied irradiation temperature. It is indicated that the most severe degradation of tensile ductility occurs in the temperature range of 275 to 350 C. Comparison with literature data revealed a large scatter in irradiation hardening at irradiation temperatures above 325 C.

  4. Irradiated Materials Testing Complex (IMTL) The Irradiated Materials Testing Laboratory provides the capability to conduct high temperature

    E-Print Network [OSTI]

    Kamat, Vineet R.

    provides the capability to conduct high temperature corrosion and stress corrosion cracking of neutron next to a hot cell. This configuration allows us to disconnect the autoclave from its water loop, maneuver it into the hot cell, where the neutron irradiated specimens can be safely mounted

  5. Development and testing of an aerosol/stratus cloud parameterization scheme for middle and high latitudes. Year 3 technical progress report, November 1, 1996--August 31, 1997

    SciTech Connect (OSTI)

    Kreidenweis, S.M.; Cotton, W.R.

    1997-09-02T23:59:59.000Z

    At the present time, general circulation models (GCMs) poorly represent clouds, to the extent that they cannot be relied upon to simulate the climatic effects of increasing concentrations of greenhouse gases, or of anthropogenic perturbations to concentrations of cloud condensation nuclei (CCN) or ice nuclei (IN). The net radiative forcing of clouds varies strongly with latitude. Poleward of 30 degrees in both hemispheres, low-level clouds create a net cooling effect corresponding to radiative divergences of {minus}50 to {minus}100 W/m{sup 2}. It is likely that a combination of fogs, boundary-layer stratocumulus, and stratus clouds are the main contributors to this forcing. Models of the response of the microphysical and radiative properties of clouds to changes in aerosol abundance, for a variety of large-scale meteorological forcings, are important additions to GCMs used for the study of the role of Arctic systems in global climate. The overall objective of this research is the development of an aerosol/cloud microphysics parameterization of mixed-phase stratus and boundary-layer clouds which responds to variations in CCN and IN. The parameterization is to be designed for ultimate use in GCM simulations as a tool in understanding the role of CCN, IN, and Arctic clouds in radiation budgets. Several versions of the CSU RAMS (Regional Atmospheric Modeling System) will be used during the course of this work. The parameterizations developed in this research are intended for application in a single-column cloud model, designed as an adaptive grid model which can interface into a GCM vertical grid through distinct layers of the troposphere where the presence of layer clouds is expected.

  6. Characterization of the neutron irradiation system for use in the Low-Dose-Rate Irradiation Facility at Sandia National Laboratories.

    SciTech Connect (OSTI)

    Franco, Manuel,

    2014-08-01T23:59:59.000Z

    The objective of this work was to characterize the neutron irradiation system consisting of americium-241 beryllium (241AmBe) neutron sources placed in a polyethylene shielding for use at Sandia National Laboratories (SNL) Low Dose Rate Irradiation Facility (LDRIF). With a total activity of 0.3 TBq (9 Ci), the source consisted of three recycled 241AmBe sources of different activities that had been combined into a single source. The source in its polyethylene shielding will be used in neutron irradiation testing of components. The characterization of the source-shielding system was necessary to evaluate the radiation environment for future experiments. Characterization of the source was also necessary because the documentation for the three component sources and their relative alignment within the Special Form Capsule (SFC) was inadequate. The system consisting of the source and shielding was modeled using Monte Carlo N-Particle transport code (MCNP). The model was validated by benchmarking it against measurements using multiple techniques. To characterize the radiation fields over the full spatial geometry of the irradiation system, it was necessary to use a number of instruments of varying sensitivities. First, the computed photon radiography assisted in determining orientation of the component sources. With the capsule properly oriented inside the shielding, the neutron spectra were measured using a variety of techniques. A N-probe Microspec and a neutron Bubble Dosimeter Spectrometer (BDS) set were used to characterize the neutron spectra/field in several locations. In the third technique, neutron foil activation was used to ascertain the neutron spectra. A high purity germanium (HPGe) detector was used to characterize the photon spectrum. The experimentally measured spectra and the MCNP results compared well. Once the MCNP model was validated to an adequate level of confidence, parametric analyses was performed on the model to optimize for potential experimental configurations and neutron spectra for component irradiation. The final product of this work is a MCNP model validated by measurements, an overall understanding of neutron irradiation system including photon/neutron transport and effective dose rates throughout the system, and possible experimental configurations for future irradiation of components.

  7. Effects of electron beam irradiation on polyamide 12 with fiberglass reinforcement

    SciTech Connect (OSTI)

    Jeun, Joon-Pyo; Shin, Bum-Sik; Kim, Hyun-Bin; Nho, Young-Chang; Kang, Phil-Hyun [Radiation Research Division for Industry and Environment, Korea Atomic Energy Research Institute, 1266 Shinjeong-dong Jeongeup-si Jellabuk-do 580-185 (Korea, Republic of)

    2010-06-02T23:59:59.000Z

    In the present study, the effects of electron beam irradiation of polyamide 12 (PA12) with fiberglass reinforcement on the thermal and wear properties were investigated. Electron beam irradiation of PA 12 was carried out over a range of irradiation doses (100-600 kGy) in air. The gel formation in the presence of a curing agent was dependent on the radiation doses. The thermal properties of irradiated PA 12 were studied in the temperature region 50-250 deg. C to observe the changes in the melting point with radiation dose. The dimensional stability was significantly increased by electron beam irradiation and the related crosslinking of the PA 12.

  8. Recent Accomplishments in the Irradiation Testing of Engineering-Scale Monolithic Fuel Specimens

    SciTech Connect (OSTI)

    N.E. Woolstenhulme; D.M. Wachs; M.K. Meyer; H.W. Glunz; R.B. Nielson

    2012-10-01T23:59:59.000Z

    The US fuel development team is focused on qualification and demonstration of the uranium-molybdenum monolithic fuel including irradiation testing of engineering-scale specimens. The team has recently accomplished the successful irradiation of the first monolithic multi-plate fuel element assembly within the AFIP-7 campaign. The AFIP-6 MKII campaign, while somewhat truncated by hardware challenges, exhibited successful irradiation of a large-scale monolithic specimen under extreme irradiation conditions. The channel gap and ultrasonic data are presented for AFIP-7 and AFIP-6 MKII, respectively. Finally, design concepts are summarized for future irradiations such as the base fuel demonstration and design demonstration experiment campaigns.

  9. Microstructure and mechanical behavior of neutron irradiated ultrafine grained ferritic steel

    SciTech Connect (OSTI)

    Ahmad Alsabbagh; Apu Sarkar; Brandon Miller; Jatuporn Burns; Leah Squires; Douglas Porter; James I. Cole; K. L. Murty

    2014-10-01T23:59:59.000Z

    Neutron irradiation effects on ultra-fine grain (UFG) low carbon steel prepared by equal channel angular pressing (ECAP) has been examined. Counterpart samples with conventional grain (CG) sizes have been irradiated alongside with the UFG ones for comparison. Samples were irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to 1.24 dpa. Atom probe tomography revealed manganese, silicon-enriched clusters in both ECAP and CG steel after neutron irradiation. X-ray quantitative analysis showed that dislocation density in CG increased after irradiation. However, no significant change was observed in UFG steel revealing better radiation tolerance.

  10. Origins of ion irradiation-induced Ga nanoparticle motion on GaAs surfaces

    SciTech Connect (OSTI)

    Kang, M.; Wu, J. H.; Chen, H. Y.; Thornton, K.; Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Sofferman, D. L. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, Adelphi University, Garden City, New York 11530-0701 (United States); Beskin, I. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-1040 (United States)

    2013-08-12T23:59:59.000Z

    We have examined the origins of ion irradiation-induced nanoparticle (NP) motion. Focused-ion-beam irradiation of GaAs surfaces induces random walks of Ga NPs, which are biased in the direction opposite to that of ion beam scanning. Although the instantaneous NP velocities are constant, the NP drift velocities are dependent on the off-normal irradiation angle, likely due to a difference in surface non-stoichiometry induced by the irradiation angle dependence of the sputtering yield. It is hypothesized that the random walks are initiated by ion irradiation-induced thermal fluctuations, with biasing driven by anisotropic mass transport.

  11. Detection of irradiated spices using photo-stimulated luminescence technique (PSL)

    SciTech Connect (OSTI)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi [Faculty of Science and Technology, National University of Malaysia, Bangi, 43000 Kajang, Selangor (Malaysia); Othman, Zainon; Abdullah, Wan Saffiey Wan [Malaysian Nuclear Agency, Bangi 43000 Kajang, Selangor (Malaysia)

    2014-09-03T23:59:59.000Z

    Photo-stimulated luminescence (PSL) technique was applied to detect irradiated black pepper (Piper nigrum), cinnamon (Cinnamomum verum) and turmeric (Curcuma longa) after dark storage for 1 day, 3 and 6 months. Using screening and calibrated PSL, all samples were correctly discriminated between non-irradiated and spices irradiated with doses 1, 5 and 10 kGy. The PSL photon counts (PCs) of irradiated spices increased with increasing dose, with turmeric showing highest sensitivity index to irradiation compared to black pepper and cinnamon. The differences in response are possibly attributed to the varying quantity and quality of silicate minerals present in each spice sample. PSL signals of all irradiated samples reduced after 3 and 6 months storage. The results of this study provide a useful database on the applicability of PSL technique for the detection of Malaysian irradiated spices.

  12. UV solar irradiance in observations and the NRLSSI and SATIRE-S models

    E-Print Network [OSTI]

    Yeo, K L; Krivova, N A; Solanki, S K; Unruh, Y C; Morrill, J

    2015-01-01T23:59:59.000Z

    Total solar irradiance and UV spectral solar irradiance have been monitored since 1978 through a succession of space missions. This is accompanied by the development of models aimed at replicating solar irradiance by relating the variability to solar magnetic activity. The NRLSSI and SATIRE-S models provide the most comprehensive reconstructions of total and spectral solar irradiance over the period of satellite observation currently available. There is persistent controversy between the various measurements and models in terms of the wavelength dependence of the variation over the solar cycle, with repercussions on our understanding of the influence of UV solar irradiance variability on the stratosphere. We review the measurement and modelling of UV solar irradiance variability over the period of satellite observation. The SATIRE-S reconstruction is consistent with spectral solar irradiance observations where they are reliable. It is also supported by an independent, empirical reconstruction of UV spectral s...

  13. Conceptual Design Report for the Irradiated Materials Characterization Laboratory (IMCL)

    SciTech Connect (OSTI)

    Stephanie Austad

    2010-06-01T23:59:59.000Z

    This document describes the design at a conceptual level for the Irradiated Materials Characterization Laboratory (IMCL) to be located at the Materials and Fuels Complex (MFC) at the Idaho National Laboratory (INL). The IMCL is an 11,000-ft2, Hazard Category-2 nuclear facility that is designed for use as a state of the-art nuclear facility for the purpose of hands-on and remote handling, characterization, and examination of irradiated and nonirradiated nuclear material samples. The IMCL will accommodate a series of future, modular, and reconfigurable instrument enclosures or caves. To provide a bounding design basis envelope for the facility-provided space and infrastructure, an instrument enclosure or cave configuration was developed and is described in some detail. However, the future instrument enclosures may be modular, integral with the instrument, or reconfigurable to enable various characterization environments to be configured as changes in demand occur. They are not provided as part of the facility.

  14. Development of positron annihilation spectroscopy for characterizing neutron irradiated tungsten

    SciTech Connect (OSTI)

    C.N. Taylor; M. Shimada; D.W. Akers; M.W. Drigert; B.J. Merrill; Y. Hatano

    2013-05-01T23:59:59.000Z

    Tungsten samples (6 mm diameter, 0.2 mm thick) were irradiated to 0.025 and 0.3 dpa with neutrons in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Samples were then exposed to deuterium plasma in the tritium plasma experiment (TPE) at 100, 200 and 500ºC to a total fluence of 1 x 1026 m-2. Nuclear reaction analysis (NRA) and Doppler broadening positron annihilation spectroscopy (DB-PAS) were performed at various stages to characterize damage and retention. We present the first known results of neutron damaged tungsten characterized by DB-PAS in order to study defect concentration. Two positron sources, 22Na and 68Ge, probe ~58 µm and through the entire 200 µm thick samples, respectively. DB-PAS results reveal clear differences between the various irradiated samples. These results, and the calibration of DB-PAS to NRA data are presented.

  15. Production of sodium-22 from proton irradiated aluminum

    DOE Patents [OSTI]

    Taylor, Wayne A. (Los Alamos, NM); Heaton, Richard C. (Los Alamos, NM); Jamriska, David J. (Los Alamos, NM)

    1996-01-01T23:59:59.000Z

    A process for selective separation of sodium-22 from a proton irradiated minum target including dissolving a proton irradiated aluminum target in hydrochloric acid to form a first solution including aluminum ions and sodium ions, separating a portion of the aluminum ions from the first solution by crystallization of an aluminum salt, contacting the remaining first solution with an anion exchange resin whereby ions selected from the group consisting of iron and copper are selectively absorbed by the anion exchange resin while aluminum ions and sodium ions remain in solution, contacting the solution with an cation exchange resin whereby aluminum ions and sodium ions are adsorbed by the cation exchange resin, and, contacting the cation exchange resin with an acid solution capable of selectively separating the adsorbed sodium ions from the cation exchange resin while aluminum ions remain adsorbed on the cation exchange resin is disclosed.

  16. Advanced Post-Irradiation Examination Capabilities Alternatives Analysis Report

    SciTech Connect (OSTI)

    Jeff Bryan; Bill Landman; Porter Hill

    2012-12-01T23:59:59.000Z

    An alternatives analysis was performed for the Advanced Post-Irradiation Capabilities (APIEC) project in accordance with the U.S. Department of Energy (DOE) Order DOE O 413.3B, “Program and Project Management for the Acquisition of Capital Assets”. The Alternatives Analysis considered six major alternatives: ? No Action ? Modify Existing DOE Facilities – capabilities distributed among multiple locations ? Modify Existing DOE Facilities – capabilities consolidated at a few locations ? Construct New Facility ? Commercial Partnership ? International Partnerships Based on the alternatives analysis documented herein, it is recommended to DOE that the advanced post-irradiation examination capabilities be provided by a new facility constructed at the Materials and Fuels Complex at the Idaho National Laboratory.

  17. TEM Examination of Advanced Alloys Irradiated in ATR

    SciTech Connect (OSTI)

    Jian Gan, PhD

    2007-09-01T23:59:59.000Z

    Successful development of materials is critical to the deployment of advanced nuclear power systems. Irradiation studies of candidate materials play a vital role for better understanding materials performance under various irradiation environments of advanced system designs. In many cases, new classes of materials have to be investigated to meet the requirements of these advanced systems. For applications in the temperature range of 500 800ºC which is relevant to the fast neutron spectrum burner reactors for the Global Nuclear Energy Partnership (GNEP) program, oxide dispersion strengthened (ODS) and ferritic martensitic steels (e.g., MA957 and others) are candidates for advanced cladding materials. In the low temperature regions of the core (<600ºC), alloy 800H, HCM12A (also called T 122) and HT 9 have been considered.

  18. Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts

    SciTech Connect (OSTI)

    Paul Demkowicz; Scott Ploger; John Hunn; Jay S. Kehn

    2012-09-01T23:59:59.000Z

    The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Six irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These six compacts also included all four TRISO coating variations irradiated in the AGR experiment. The six compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. From 36 to 79 particles within each cross section were exposed near enough to midplane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 931 classified particles allowed other relationships among morphological types to be established.

  19. Ceramographic Examinations of Irradiated AGR-1 Fuel Compacts

    SciTech Connect (OSTI)

    Paul Demkowicz; Scott Ploger; John Hunn

    2012-05-01T23:59:59.000Z

    The AGR 1 experiment involved irradiating 72 cylindrical fuel compacts containing tri-structural isotropic (TRISO)-coated particles to a peak burnup of 19.5% fissions per initial metal atom with no in-pile failures observed out of almost 300,000 particles. Five irradiated AGR 1 fuel compacts were selected for microscopy that span a range of irradiation conditions (temperature, burnup, and fast fluence). These five compacts also included all four TRISO coating variations irradiated in the AGR experiment. The five compacts were cross-sectioned both transversely and longitudinally, mounted, ground, and polished after development of careful techniques for preserving particle structures against preparation damage. Approximately 40 to 80 particles within each cross section were exposed near enough to mid-plane for optical microscopy of kernel, buffer, and coating behavior. The microstructural analysis focused on kernel swelling and porosity, buffer densification and fracture, debonding between the buffer and inner pyrolytic carbon (IPyC) layers, and fractures in the IPyC and SiC layers. Three basic particle morphologies were established according to the extent of bonding between the buffer and IPyC layers: complete debonding along the interface (Type A), no debonding along the interface (Type B), and partial debonding (Type AB). These basic morphologies were subdivided according to whether the buffer stayed intact or fractured. The resulting six characteristic morphologies were used to classify particles within each cross section, but no spatial patterns were clearly observed in any of the cross-sectional morphology maps. Although positions of particle types appeared random within compacts, examining a total of 830 classified particles allowed other relationships among morphological types to be established.

  20. Post Irradiation Capabilities at the Idaho National Laboratory

    SciTech Connect (OSTI)

    J. L. Schulthess; K. E. Rosenberg

    2011-05-01T23:59:59.000Z

    The U.S. Department of Energy (DOE), Office of Nuclear Energy (NE) oversees the efforts to ensure nuclear energy remains a viable option for the United States. A significant portion of these efforts are related to post-irradiation examinations (PIE) of highly activated fuel and materials that are subject to the extreme environment inside a nuclear reactor. As the lead national laboratory, Idaho National Laboratory (INL) has a rich history, experience, workforce and capabilities for performing PIE. However, new advances in tools and techniques for performing PIE now enable understanding the performance of fuels and materials at the nano-scale and smaller level. Examination at this level is critical since this is the scale at which irradiation damage occurs. The INL is on course to adopt these advanced tools and techniques to develop a comprehensive nuclear fuels and materials characterization capability that is unique in the world. Because INL has extensive PIE capabilities currently in place, a strong foundation exist to build upon as new capabilities are implemented and work load increases. In the recent past, INL has adopted significant capability to perform advanced PIE characterization. Looking forward, INL is planning for the addition of two facilities that will be built to meet the stringent demands of advanced tools and techniques for highly activated fuels and materials characterization. Dubbed the Irradiated Materials Characterization Laboratory (IMCL) and Advanced Post Irradiation Examination Capability , these facilities are next generation PIE laboratories designed to perform the work of PIE that cannot be performed in current DOE facilities. In addition to physical capabilities, INL has recently added two significant contributors to the Advanced Test Reactor-National Scientific User Facility (ATR-NSUF), Oak Ridge National Laboratory and University of California, Berkeley.

  1. Method for improving performance of irradiated structural materials

    DOE Patents [OSTI]

    Megusar, Janez (Belmont, MA); Harling, Otto K. (Hingham, MA); Grant, Nicholas J. (Winchester, MA)

    1989-01-01T23:59:59.000Z

    Method for extending service life of nuclear reactor components prepared from ductile, high strength crystalline alloys obtained by devitrification of metallic glasses. Two variations of the method are described: (1) cycling the temperature of the nuclear reactor between the operating temperature which leads to irradiation damage and a l The U.S. Government has rights in this invention by virtue of Department of Energy, Office of Fusion Energy, Grant No. DE-AC02-78ER-10107.

  2. Nonlinear broadband photoluminescence of graphene induced by femtosecond laser irradiation

    SciTech Connect (OSTI)

    Liu, Wei-Tao; Wu, S.W.; Schuck, P.J.; Salmeron, Miquel; Shen, Y.R.; Wang, F.

    2010-07-01T23:59:59.000Z

    Upon femtosecond laser irradiation, a bright, broadband photoluminescence is observed from graphene at frequencies well above the excitation frequency. Analyses show that it arises from radiative recombination of a broad distribution of nonequilibrium electrons and holes, generated by rapid scattering between photoexcited carriers within tens of femtoseconds after the optical excitation. Its highly unusual characteristics come from the unique electronic and structural properties of graphene.

  3. Electron Beam Irradiation for Improving Safety of Fruits and Vegetables

    E-Print Network [OSTI]

    Adavi, Megha Sarthak

    2012-07-16T23:59:59.000Z

    to pathogens. Conventional techniques of sanitizing washes may not be effective since the organic matter released from the fresh produce use up the free chlorine thus reducing the sanitizing potential of wash water just when it is needed most and a heat... treatment step to kill pathogens cannot be applied if the purpose is to consume fresh produce. Electron beam (e-beam) irradiation was used to treat cut cantaloupe, cut roma tomatoes, baby spinach, romaine lettuce which were surface inoculated with a...

  4. Irradiation test of electrical insulation materials performed at

    E-Print Network [OSTI]

    McDonald, Kirk

    required for the sample irradiation Depth of bean penetration in water for various beam energy value H20 energy as 10 ­ 11 MeV is necessary Scaling from water to G10 Courtesy S. Wronka #12;Experimental;Structure 6 MeV 12 MeV 15 MeV Real electron energy MeV 4 8 11 Depth of water penetration (range 80

  5. Ion irradiation induced structural and electrical transition in graphene

    SciTech Connect (OSTI)

    Zhou Yangbo; Wang Yifan; Xu Jun; Fu Qiang; Wu Xiaosong; Yu Dapeng [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Liao Zhimin [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College, Dublin 2 (Ireland); Duesberg, Georg S. [Centre for Research on Adaptive Nanostructures and Nanodevices (CRANN), Trinity College, Dublin 2 (Ireland); School of Chemistry, Trinity College, Dublin 2 (Ireland)

    2010-12-21T23:59:59.000Z

    The relationship between the electrical properties and structure evolution of single layer graphene was studied by gradually introducing the gallium ion irradiation. Raman spectrums show a structural transition from nano-crystalline graphene to amorphous carbon as escalating the degree of disorder of the graphene sample, which is in correspondence with the electrical transition from a Boltzmann diffusion transport to a carrier hopping transport. The results show a controllable method to tune the properties of graphene.

  6. On the Absorption and Redistribution of Energy in Irradiated Planets

    E-Print Network [OSTI]

    Brad Hansen

    2008-01-18T23:59:59.000Z

    We present a sequence of toy models for irradiated planet atmospheres, in which the effects of geometry and energy redistribution are modelled self-consistently. We use separate but coupled grey atmosphere models to treat the ingoing stellar irradiation and outgoing planetary reradiation. We investigate how observed quantities such as full phase secondary eclipses and orbital phase curves depend on various important parameters, such as the depth at which irradiation is absorbed and the depth at which energy is redistributed. We also compare our results to the more detailed radiative transfer models in the literature, in order to understand how those map onto the toy model parameter space. Such an approach can prove complementary to more detailed calculations, in that they demonstrate, in a simple way, how the solutions change depending on where, and how, energy redistribution occurs. As an example of the value of such models, we demonstrate how energy redistribution and temperature equilibration at moderate optical depths can lead to temperature inversions in the planetary atmosphere, which may be of some relevance to recent observational findings.

  7. Thermal Structure and Radius Evolution of Irradiated Gas Giant Planets

    E-Print Network [OSTI]

    Phil Arras; Lars Bildsten

    2006-01-15T23:59:59.000Z

    We consider the thermal structure and radii of strongly irradiated gas giant planets over a range in mass and irradiating flux. The cooling rate of the planet is sensitive to the surface boundary condition, which depends on the detailed manner in which starlight is absorbed and energy redistributed by fluid motion. We parametrize these effects by imposing an isothermal boundary condition $T \\equiv T_{\\rm deep}$ below the photosphere, and then constrain $T_{\\rm deep}$ from the observed masses and radii. We compute the dependence of luminosity and core temperature on mass, $T_{\\rm deep}$ and core entropy, finding that simple scalings apply over most of the relevant parameter space. These scalings yield analytic cooling models which exhibit power-law behavior in the observable age range $0.1-10 {\\rm Gyr}$, and are confirmed by time-dependent cooling calculations. We compare our model to the radii of observed transiting planets, and derive constraints on $T_{\\rm deep}$. Only HD 209458 has a sufficiently accurate radius measurement that $T_{\\rm deep}$ is tightly constrained; the lower error bar on the radii for other planets is consistent with no irradiation. More accurate radius and age measurements will allow for a determination of the correlation of $T_{\\rm deep}$ with the equilibrium temperature, informing us about both the greenhouse effect and day-night asymmetries.

  8. Effects of mass loss for highly-irradiated giant planets

    E-Print Network [OSTI]

    W. B. Hubbard; M. F. Hattori; A. Burrows; I. Hubeny; D. Sudarsky

    2006-10-27T23:59:59.000Z

    We present calculations for the evolution and surviving mass of highly-irradiated extrasolar giant planets (EGPs) at orbital semimajor axes ranging from 0.023 to 0.057 AU using a generalized scaled theory for mass loss, together with new surface-condition grids for hot EGPs and a consistent treatment of tidal truncation. Theoretical estimates for the rate of energy-limited hydrogen escape from giant-planet atmospheres differ by two orders of magnitude, when one holds planetary mass, composition, and irradiation constant. Baraffe et al. (2004, A&A 419, L13-L16) predict the highest rate, based on the theory of Lammer et al. (2003, Astrophys. J. 598, L121-L124). Scaling the theory of Watson et al. (1981, Icarus 48, 150-166) to parameters for a highly-irradiated exoplanet, we find an escape rate ~102 lower than Baraffe's. With the scaled Watson theory we find modest mass loss, occurring early in the history of a hot EGP. In this theory, mass loss including the effect of Roche-lobe overflow becomes significant primarily for masses below a Saturn mass, for semimajor axes = 0.023 AU. This contrasts with the Baraffe model, where hot EGPs are claimed to be remnants of much more massive bodies, originally several times Jupiter and still losing substantial mass fractions at present.

  9. IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

    SciTech Connect (OSTI)

    M.K. Meyer; J. Gan; J.-F. Jue; D.D. Keiser; E. Perez; A. Robinson; D.M. Wachs; N. Woolstenhulme; G.L. Hofman; Y.-S. Kim

    2014-04-01T23:59:59.000Z

    High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  10. Post-irradiation Examination Plan for ORNL and University of California Santa Barbara Assessment of UCSB ATR-2 Irradiation Experiment

    SciTech Connect (OSTI)

    Nanstad, R. K. [Materials Science and Technology Division, Oak Ridge National Laboratory; Yamamoto, T. [University of California Santa Barbara; Sokolov, M. A. [Materials Science and Technology Division, Oak Ridge National Laboratory

    2014-01-25T23:59:59.000Z

    New and existing databases will be combined to support development of physically based models of transition temperature shifts (TTS) for high fluence-low flux (? < 10{sup 11}n/cm{sup 2}-s) conditions, beyond the existing surveillance database, to neutron fluences of at least 1×10{sup 20} n/cm{sup 2} (>1 MeV). All references to neutron flux and fluence in this report are for fast neutrons (>1 MeV). The reactor pressure vessel (RPV) task of the Light Water Reactor Sustainability (LWRS) Program is working with various organizations to obtain archival surveillance materials from commercial nuclear power plants to allow for comparisons of the irradiation-induced microstructural features from reactor surveillance materials with those from similar materials irradiated under high flux conditions in test reactors

  11. Heavy-Section Steel Irradiation Program on irradiation effects in light-water reactor pressure vessel materials

    SciTech Connect (OSTI)

    Nanstad, R.K.; Corwin, W.R.; Alexander, D.J.; Haggag, F.M.; Iskander, S.K.; McCabe, D.E.; Sokolov, M.A.; Stoller, R.E. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.

    1995-07-01T23:59:59.000Z

    The safety of commercial light-water nuclear plants is highly dependent on the structural integrity of the reactor pressure vessel (RPV). In the absence of radiation damage to the RPV, fracture of the vessel is difficult to postulate. Exposure to high energy neutrons can result in embrittlement of radiation-sensitive RPV materials. The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory, sponsored by the US Nuclear Regulatory Commission (USNRC), is assessing the effects of neutron irradiation on RPV material behavior, especially fracture toughness. The results of these and other studies are used by the USNRC in the evaluation of RPV integrity and regulation of overall nuclear plant safety. In assessing the effects of irradiation, prototypic RPV materials are characterized in the unirradiated condition and exposed to radiation under varying conditions. Mechanical property tests are conducted to provide data which can be used in the development of guidelines for structural integrity evaluations, while metallurgical examinations and mechanistic modeling are performed to improve understanding of the mechanisms responsible for embrittlement. The results of these investigations, in conjunction with results from commercial reactor surveillance programs, are used to develop a methodology for the prediction of radiation effects on RPV materials. This irradiation-induced degradation of the materials can be mitigated by thermal annealing, i.e., heating the RPV to a temperature above that of normal operation. Thus, thermal annealing and evaluation of reirradiation behavior are major tasks of the HSSI Program. This paper describes the HSSI Program activities by summarizing some past and recent results, as well as current and planned studies. 30 refs., 8 figs., 1 tab.

  12. Booster irradiation to the spleen following total body irradiation. A new immunosuppressive approach for allogeneic bone marrow transplantation

    SciTech Connect (OSTI)

    Lapidot, T.; Singer, T.S.; Salomon, O.; Terenzi, A.; Schwartz, E.; Reisner, Y.

    1988-10-15T23:59:59.000Z

    Graft rejection presents a major obstacle for transplantation of T cell-depleted bone marrow in HLA-mismatched patients. In a primate model, after conditioning exactly as for leukemia patients, it was shown that over 99% of the residual host clonable T cells are concentrated in the spleen on day 5 after completion of cytoreduction. We have now corroborated these findings in a mouse model. After 9-Gy total body irradiation (TBI), the total number of Thy-1.2+ cells in the spleen reaches a peak between days 3 and 4 after TBI. The T cell population is composed of both L3T4 (helper) and Lyt-2 (suppressor) T cells, the former being the major subpopulation. Specific booster irradiation to the spleen (5 Gy twice) on days 2 and 4 after TBI greatly enhances production of donor-type chimera after transplantation of T cell-depleted allogeneic bone marrow. Similar enhancement can be achieved by splenectomy on day 3 or 4 after TBI but not if splenectomy is performed 1 day before TBI or 1 day after TBI, strengthening the hypothesis that, after lethal TBI in mice, the remaining host T cells migrate from the periphery to the spleen. These results suggest that a delayed booster irradiation to the spleen may be beneficial as an additional immunosuppressive agent in the conditioning of leukemia patients, in order to reduce the incidence of bone marrow allograft rejection.

  13. Irradiation performance of fast reactor MOX fuel pins with ferritic/martensitic cladding irradiated to high burnups

    SciTech Connect (OSTI)

    Uwaba, Tomoyuki; Ito, Masahiro; Mizuno, Tomoyasu; Katsuyama, Kozo; Makenas, Bruce J.; Wootan, David W.; Carmack, Jon

    2011-06-16T23:59:59.000Z

    The ACO-3 irradiation test, which attained extremely high burnups of about 232 GWd/t and resisted a high neutron fluence (E > 0.1 MeV) of about 39E26 n/m2 as one of the lead tests of the Core Demonstration Experiment in the Fast Flux Test Facility, demonstrated that the fuel pin cladding made of ferritic/martensitic HT-9 alloy had superior void swelling resistance. The measured diameter profiles of the irradiated ACO-3 fuel pins showed axially extensive incremental strain in the MOX fuel column region and localized incremental strain near the interfaces between the MOX fuel and upper blanket columns. These incremental strains were as low as 1.5% despite the extremely high level of the fast neutron fluence. Evaluation of the pin diametral strain indicated that the incremental strain in the MOX fuel column region was substantially due to cladding void swelling and irradiation creep caused by internal fission gas pressure, while the localized strain near the MOX fuel/upper blanket interface was likely the result of the pellet/cladding mechanical interaction (PCMI) caused by cesium/fuel reactions. The evaluation also suggested that the PCMI was effectively mitigated by a large gap size between the cladding and blanket column.

  14. Irradiation performance of fast reactor MOX fuel pins with ferritic/martensitic cladding irradiated to high burnups

    SciTech Connect (OSTI)

    Tomoyuki Uwaba; Masahiro Ito; Kozo Katsuyama; Bruce J. Makenas; David W. Wootan; Jon Carmack

    2011-05-01T23:59:59.000Z

    The ACO-3 irradiation test, which attained extremely high burnups of about 232 GWd/t and resisted a high neutron fluence (E > 0.1 MeV) of about 39 × 1026 n/m2 as one of the lead tests of the Core Demonstration Experiment in the Fast Flux Test Facility, demonstrated that the fuel pin cladding made of ferritic/martensitic HT-9 alloy had superior void swelling resistance. The measured diameter profiles of the irradiated ACO-3 fuel pins showed axially extensive incremental strain in the MOX fuel column region and localized incremental strain near the interfaces between the MOX fuel and upper blanket columns. These incremental strains were as low as 1.5% despite the extremely high level of the fast neutron fluence. Evaluation of the pin diametral strain indicated that the incremental strain in the MOX fuel column region was substantially due to cladding void swelling and irradiation creep caused by internal fission gas pressure, while the localized strain near the MOX fuel/upper blanket interface was likely the result of the pellet/cladding mechanical interaction (PCMI) caused by cesium/fuel reactions. The evaluation also suggested that the PCMI was effectively mitigated by a large gap size between the cladding and blanket column.

  15. The effect of neutron irradiation on the mechanical properties of C/SiC composites

    SciTech Connect (OSTI)

    Shih, Chunghao [ORNL] [ORNL; Katoh, Yutai [ORNL] [ORNL; Snead, Lance Lewis [ORNL] [ORNL; Steinbeck, John [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The effects of neutron irradiation to 3.5 and 9.5 dpa at 730 C on a 2D plain woven carbon fiber reinforced polymer derived SiC matrix composite are presented. For both fluences, the irradiation caused in-plane contraction and trans-plane expansion. Irradiation also caused substantial reduction in composite flexural strength (54%) and increase in flexural tangent modulus (+85%). The extents of dimensional/ mechanical property changes were greater for the higher fluence irradiated samples. Those changes suggest the instability of the polymer derived SiC matrix following irradiation. The nature of the mechanical property changes suggest increased clamping stress between the fiber and the matrix. The composite property changes are explained in terms of irradiation effects on composite constituents and are compared with carbon fiber reinforced carbon matrix composite as a reference material.

  16. Irradiation of commercial, high-Tc superconducting tape for potential fusion applications: electromagnetic transport properties

    SciTech Connect (OSTI)

    Aytug, Tolga [ORNL; Gapud, Albert A. [University of South Alabama, Mobile; List III, Frederick Alyious [ORNL; Leonard, Keith J [ORNL; Rupich, Marty [American Superconductor Corporation, Westborough, MA; Zhang, Yanwen [ORNL; Greenwood, N T [University of South Alabama, Mobile; Alexander, J A [University of South Alabama, Mobile; Khan, A [University of South Alabama, Mobile

    2015-01-01T23:59:59.000Z

    Effects of low dose irradiation on the electrical transport current properties of commercially available high-temperature superconducting, coated-conductor tapes were investigated, in view of potential applications in the irradiative environment of fusion reactors. Three different tapes, each with unique as-grown flux-pinning structures, were irradiated with Au and Ni ions at energies that provide a range of damage effects, with accumulated damage levels near that expected for conductors in a fusion reactor environment. Measurements using transport current determined the pre- and post-irradiation resistivity, critical current density, and pinning force density, yielding critical temperatures, irreversibility lines, and inferred vortex creep rates. Results show that at the irradiation damage levels tested, any detriment to as-grown pre-irradiation properties is modest; indeed in one case already-superior pinning forces are enhanced, leading to higher critical currents.

  17. Formation of long-range ordered quantum dots arrays in amorphous matrix by ion beam irradiation

    SciTech Connect (OSTI)

    Buljan, M. [Charles University in Prague, Prague 12116 (Czech Republic); Ruder Boskovic Institute, Zagreb 10000 (Croatia); Bogdanovic-Radovic, I.; Karlusic, M.; Desnica, U. V.; Radic, N.; Dubcek, P. [Ruder Boskovic Institute, Zagreb 10000 (Croatia); Drazic, G. [Jozef Stefan Institute, Ljubljana 1000 (Slovenia); Salamon, K. [Institute of Physics, Zagreb 10000 (Croatia); Bernstorff, S. [Sincrotrone Trieste, Basovizza 34012 (Italy); Holy, V. [Charles University in Prague, Prague 12116 (Czech Republic)

    2009-08-10T23:59:59.000Z

    We demonstrate the production of a well ordered three-dimensional array of Ge quantum dots in amorphous silica matrix. The ordering is achieved by ion beam irradiation and annealing of a multilayer film. Structural analysis shows that quantum dots nucleate along the direction of the ion beam used for irradiation, while the mutual distance of the quantum dots is determined by the diffusion properties of the multilayer material rather than the distances between traces of ions that are used for irradiation.

  18. Temperature dependence of fracture toughness in HT9 steel neutron-irradiated up to 145 dpa

    SciTech Connect (OSTI)

    Baek, Jong-Hyuk [KAERI] [KAERI; Byun, Thak Sang [ORNL] [ORNL; Maloy, S [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Toloczko, M [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL)

    2014-01-01T23:59:59.000Z

    The temperature dependence of fracture toughness in HT9 steel irradiated to high doses was investigated using miniature three-point bend (TPB) fracture specimens. These specimens were from the ACO-3 fuel duct wall of the Fast Flux Test Facility (FFTF), in which irradiation doses were in the range of 3.2 144.8 dpa and irradiation temperatures in the range of 380.4 502.6 oC. A miniature specimen reuse technique has been established for this investigation: the specimens used were the tested halves of miniature Charpy impact specimens (~13 3 4 mm) with diamond-saw cut in the middle. The fatigue precracking for specimens and fracture resistance (J-R) tests were carried out in a MTS servo-hydraulic testing machine with a vacuum furnace following the standard procedure described in the ASTM Standard E 1820-09. For each of five irradiated and one archive conditions, 7 to 9 J-R tests were performed at selected temperatures ranging from 22 C to 600 C. The fracture toughness of the irradiated HT9 steel was strongly dependent on irradiation temperatures rather than irradiation dose. When the irradiation temperature was below about 430 C, the fracture toughness of irradiated HT9 increased with test temperature, reached an upper shelf of 180 200 MPa m at 350 450 C and then decreased with test temperature. When the irradiation temperature 430 C, the fracture toughness was nearly unchanged until about 450 C and decreased with test temperature in higher temperature range. Similar test temperature dependence was observed for the archive material although the highest toughness values are lower after irradiation. Ductile stable crack growth occurred except for a few cases where both the irradiation temperature and test temperature are relatively low.

  19. SUBTHRESHOLD DISPLACEMENT DAMAGE IN COPPER-ALUMINUM ALLOYS DURING ELECTRON IRRADIATION

    E-Print Network [OSTI]

    Drosd, R.

    2010-01-01T23:59:59.000Z

    DAMAGE IN COPPER-ALUMINUM ALLOYS DURING ELECTRON IRRADIATIONDAMAGE IN COPPER-ALUMINUM ALLOYS DURING ELECTRON IRRADIATIONby irradiating copper-aluminum alloys at high tempera­ tures

  20. The second and third NGNP advanced gas reactor fuel irradiation experiments

    SciTech Connect (OSTI)

    Grover, S. B.; Petti, D. A. [Idaho National Laboratory, 2525 N. Fremont Ave., Idaho Falls, ID 83415 (United States)

    2012-07-01T23:59:59.000Z

    The United States Dept. of Energy's Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program is currently scheduled to irradiate a total of five low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The irradiations are being accomplished to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas cooled reactors. The experiments will each consist of at least six separate capsules, and will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The effluent sweep gas will also have on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and completed a very successful irradiation in early November 2009. The second experiment (AGR-2) started irradiation in June 2010, and the third and fourth experiments have been combined into a single larger irradiation (AGR-3/4) that is currently being assembled. The design and status of the second through fourth experiments as well as the irradiation results of the second experiment to date are discussed. (authors)

  1. Solar irradiance forecasting at multiple time horizons and novel methods to evaluate uncertainty

    E-Print Network [OSTI]

    Marquez, Ricardo

    2012-01-01T23:59:59.000Z

    Solar Irradiance And Power Output Variability In November 2009, UC Merced deployed a SunPower PV system provided with single axis tracking

  2. Accumulation and Recovery of Disorder in Au2+-Irradiated Cd2Nb2O7...

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

    of the disorder has been observed below room temperature. Citation: Jiang W, WJ Weber, and LA Boatner.2005."Accumulation and Recovery of Disorder in Au2+-Irradiated...

  3. Effects of helium content of microstructural development in Type 316 stainless steel under neutron irradiation

    SciTech Connect (OSTI)

    Maziasz, P.J.

    1985-11-01T23:59:59.000Z

    This work investigated the sensitivity of microstructural evolution, particularly precipitate development, to increased helium content during thermal aging and during neutron irradiation. Helium (110 at. ppM) was cold preinjected into solution annealed (SA) DO-heat type 316 stainess steel (316) via cyclotron irradiation. These specimens were then exposed side by side with uninjected samples. Continuous helium generation was increased considerably relative to EBR-II irradiation by irradiation in HFIR. Data were obtained from quantitative analytical electron microscopy (AEM) in thin foils and on extraction replicas. 480 refs., 86 figs., 19 tabs.

  4. Effect of {gamma}-irradiation on strength of concrete for nuclear-safety structures

    SciTech Connect (OSTI)

    Vodak, F. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Trtik, K. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Sopko, V. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Kapickova, O. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic); Demo, P. [Czech Technical University (CVUT), Faculty of Civil Engineering, Prague, Thakurova 7, CZ 166 29 Prague 6 (Czech Republic)]. E-mail: demo@fzu.cz

    2005-07-01T23:59:59.000Z

    Concrete applied for construction of nuclear power plant (NPP) Temelin (Czech Republic) has been exposed to {gamma}-irradiation up to dose 6x10{sup 5} Gy. Depending on the level of irradiation, changes in strength, porous structure and phase composition of the concrete have been studied. It is found that irradiation lowers both the strength of concrete (about 10%) and volume (resp. surface) of porous space. On the other hand, {gamma}-irradiation increases the ratio of calcite, CaCO{sub 3}, in the concrete. Observed effects are discussed with respect to safety of NPPs.

  5. all-sky solar irradiance: Topics by E-print Network

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

    our climate. A non-negligible influence is suggested by correlation studies between solar variability and climate indicators. The mechanism for solar irradiance variations...

  6. Testicular damage and regeneration in rats following low-level gamma irradiation

    E-Print Network [OSTI]

    Maxwell, Wesley Howard

    1974-01-01T23:59:59.000Z

    of these animals were examined using several recognized histological procedures. The sequential damage and recovezy of the germinal epithelium was s'tudied for S4 days post-irradiation. The lower dose rate (7 R/hr) resulted in temporari. ly arresting meiotic...- ation of the germinal epithelium of rats irradiated with 7 R/hr was seen by 84 days post-irradiation. However, this same time iv. was not sufficient for total recovery of the rats irradiated to a total dose of 1000 R, at 14 R/hr. ACKNOWLEDGEMENT...

  7. alpha-particles microbeam irradiation: Topics by E-print Network

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

    4 Incidence characteristics of alpha particles on detectors irradiated in a radon progeny atmosphere Biology and Medicine Websites Summary: Incidence characteristics of...

  8. Solar irradiance forecasting at multiple time horizons and novel methods to evaluate uncertainty

    E-Print Network [OSTI]

    Marquez, Ricardo

    2012-01-01T23:59:59.000Z

    114 Solar Irradiance And Power Output Variabilitytechniques for solar power output with no exogenous inputs.and their effect on solar power output. For large scale

  9. ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Hodges, Gary

    The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.

  10. UNDERSTANDING TRENDS ASSOCIATED WITH CLOUDS IN IRRADIATED EXOPLANETS

    SciTech Connect (OSTI)

    Heng, Kevin [University of Bern, Center for Space and Habitability, Sidlerstrasse 5, CH-3012 Bern (Switzerland); Demory, Brice-Olivier, E-mail: kevin.heng@csh.unibe.ch, E-mail: demory@mit.edu [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States)

    2013-11-10T23:59:59.000Z

    Unlike previously explored relationships between the properties of hot Jovian atmospheres, the geometric albedo and the incident stellar flux do not exhibit a clear correlation, as revealed by our re-analysis of Q0-Q14 Kepler data. If the albedo is primarily associated with the presence of clouds in these irradiated atmospheres, a holistic modeling approach needs to relate the following properties: the strength of stellar irradiation (and hence the strength and depth of atmospheric circulation), the geometric albedo (which controls both the fraction of starlight absorbed and the pressure level at which it is predominantly absorbed), and the properties of the embedded cloud particles (which determine the albedo). The anticipated diversity in cloud properties renders any correlation between the geometric albedo and the stellar flux weak and characterized by considerable scatter. In the limit of vertically uniform populations of scatterers and absorbers, we use an analytical model and scaling relations to relate the temperature-pressure profile of an irradiated atmosphere and the photon deposition layer and to estimate whether a cloud particle will be lofted by atmospheric circulation. We derive an analytical formula for computing the albedo spectrum in terms of the cloud properties, which we compare to the measured albedo spectrum of HD 189733b by Evans et al. Furthermore, we show that whether an optical phase curve is flat or sinusoidal depends on whether the particles are small or large as defined by the Knudsen number. This may be an explanation for why Kepler-7b exhibits evidence for the longitudinal variation in abundance of condensates, while Kepler-12b shows no evidence for the presence of condensates despite the incident stellar flux being similar for both exoplanets. We include an 'observer's cookbook' for deciphering various scenarios associated with the optical phase curve, the peak offset of the infrared phase curve, and the geometric albedo.

  11. Supine Craniospinal Irradiation Setup with Two Spine Fields

    SciTech Connect (OSTI)

    Liu, Arthur K. [University of Colorado Denver, Department of Radiation Oncology, Aurora, Colorado (United States)], E-mail: arthur.liu@uchsc.edu; Thornton, Dale; Backus, Jennifer; Dzingle, Wayne; Stoehr, Scott; Newman, Francis [University of Colorado Denver, Department of Radiation Oncology, Aurora, Colorado (United States)

    2009-10-01T23:59:59.000Z

    Craniospinal irradiation is an integral part of treatment for a number of cancers. Typically, patients are positioned prone, which allows visualization of field matches. However, a supine position allows better airway access for patients requiring anesthesia, and is more comfortable for patients. One potential difficulty with supine positioning occurs when the patient is tall and requires matching 2 spine fields. We describe a technique to match the spine fields using light fields on the bottom of the treatment table, and verified the approach on a phantom. The accuracy of the technique is demonstrated for the first 4 patients, with the majority of field gaps and overlaps below our clinical tolerance of 2 mm.

  12. Dosimetry in Thermal Neutron Irradiation Facility at BMRR

    SciTech Connect (OSTI)

    Hu, J. P. [Brookhaven National Lab. (BNL), Upton, NY (United States); Holden, N. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Reciniello, R. N.

    2014-05-23T23:59:59.000Z

    Radiation dosimetry for Neutron Capture Therapy (NCT) has been performed since 1959 at Thermal Neutron Irradiation Facility (TNIF) of the three-megawatt light-water cooled Brookhaven Medical Research Reactor (BMRR). In the early 1990s when more effective drug carriers were developed for NCT, in which the eye melanoma and brain tumors in rats were irradiated in situ, extensive clinical trials of small animals began using a focused thermal neutron beam. To improve the dosimetry at irradiation facility, a series of innovative designs and major modifications made to enhance the beam intensity and to ease the experimental sampling at BMRR were performed; including (1) in-core fuel addition to increase source strength and balance flux of neutrons towards two ports, (2) out of core moderator remodeling, done by replacing thicker D2O tanks at graphite-shutter interfacial areas, to expedite neutron thermalization, (3) beam shutter upgrade to reduce strayed neutrons and gamma dose, (4) beam collimator redesign to optimize the beam flux versus dose for animal treatment, (5) beam port shielding installation around the shutter opening area (lithium-6 enriched polyester-resin in boxes, attached with polyethylene plates) to reduce prompt gamma and fast neutron doses, (6) sample holder repositioning to optimize angle versus distance for a single organ or whole body irradiation, and (7) holder wall buildup with neutron reflector materials to increase dose and dose rate from scattered thermal neutrons. During the facility upgrade, reactor dosimetry was conducted using thermoluminescent dosimeters TLD for gamma dose estimate, using ion chambers to confirm fast neutron and gamma dose rate, and by the activation of gold-foils with and without cadmium-covers, for fast and thermal neutron flux determination. Based on the combined effect from the size and depth of tumor cells and the location and geometry of dosimeters, the measured flux from cadmium-difference method was 4 - 7 % lower than the statistical mean derived from the Monte-Carlo modeling (5% uncertainty). The dose rate measured by ion chambers was 6 - 10 % lower than the output tallies (7% uncertainty). The detailed dosimetry that was performed at the TNIF for the NCT will be described.

  13. Gamma irradiation effects on the biodegradation of lignin

    E-Print Network [OSTI]

    Krysinski, Thomas Leon

    1966-01-01T23:59:59.000Z

    4/ X / 2. 0 3. 0 4. 0 5. 0 6. 0 7. 0 Wavelength in microns 8. 0 9. 0 28 CHAPTER VI RESULTS AND CONCLUSIONS A commercia I CLS was irradiated in a dry state to various total dose levels of Co-60 gamma rays. The effects on the structure... structure of lignin and lignin derivatives, some alteration in the structure of these compounds may be necessary before any of the above treatment processes can yield a higher reduction in the residual lignin content. For many years the effects of gamma...

  14. A Search for Channel Deformation in Irradiated Vanadium Tensile Specimens

    SciTech Connect (OSTI)

    Gelles, David S.; Toloczko, Mychailo B.; Kurtz, Richard J.

    2010-02-26T23:59:59.000Z

    A miniature tensile specimen of V-4Cr-4Ti which had be irradiated in the 17J test at 425°C to 3.7 dpa was mechanically polished, deformed to 3.9% strain at room temperature, and examined by scanning and transmission electron microscopy in order to look for evidence of channel deformation. It was found that uniform deformation can occur without channel deformation, but evidence for channeling was found with channels appearing most prominently after the onset of necking. The channeling occurs on wavy planes with large variations in localized deformation from channel to channel.

  15. Toward Understanding Dynamic Annealing Processes in Irradiated Ceramics

    E-Print Network [OSTI]

    Myers, Michael

    2013-03-04T23:59:59.000Z

    values (given in the legend in units of 1012 cm?2 s?1), and (c) with a pulsed beam with different values of toff (given in the legend in units of 10?3 s) and all the other parameters fixed (fluence = 2.4 ? 1014 cm?2, ton = 1 ms, and Fon = 1.2 ? 1013... ions does not render ZnO amorphous at RT. Ion-beam-produced disorder has been intensively investigated in ZnO [2?12]. For a wide range of irradiation conditions, the level of stable post-implantation disorder in the ZnO crystal bulk depends...

  16. The effects of alpha particle irradiation on stainless steel

    E-Print Network [OSTI]

    Shipp, John Douglas

    1999-01-01T23:59:59.000Z

    and an approximation based on the first year's fluence. . . . . . . . . 17 CHAPTER I INTRODUCTION The storage of Weapons Grade Plutonium (WGPu) pits has prompted this study of the effects of alpha particle irradiation on stainless steel. Previous studies of alpha... and properties of WGPu. ISOTOPE Pu-239 Pu-240 P0-241 Density* Crystal Structure* ATOMIC ABD. (/o) 94. 0 5. 8 0. 2 15. 7 g/cm' BCC 'Note: The density and crystal structure of elemental plutonium is 19. 7 g/cm' and FCC, respectively...

  17. Low Dose Irradiation Facility | Savannah River Ecology Laboratory

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > The EnergyCenter (LMI-EFRC) - CenterLinksLow Dose Irradiation Facility

  18. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes | NationalCurriculum IntroductionInvestor14,566Irradiation

  19. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer ReviewIron is the KeyIrradiation Effects

  20. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer ReviewIron is the KeyIrradiation

  1. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh SchoolIn12 Investigation Peer ReviewIron is theIrradiation Effects on

  2. Improving Thermal Model Prediction Through Statistical Analysis of Irradiation and Post-Irradiation Data from AGR Experiments

    SciTech Connect (OSTI)

    Dr. Binh T. Pham; Grant L. Hawkes; Jeffrey J. Einerson

    2012-10-01T23:59:59.000Z

    As part of the Research and Development program for Next Generation High Temperature Reactors (HTR), a series of irradiation tests, designated as Advanced Gas-cooled Reactor (AGR), have been defined to support development and qualification of fuel design, fabrication process, and fuel performance under normal operation and accident conditions. The AGR tests employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule and instrumented with thermocouples (TC) embedded in graphite blocks enabling temperature control. The data representing the crucial test fuel conditions (e.g., temperature, neutron fast fluence, and burnup) while impossible to obtain from direct measurements are calculated by physics and thermal models. The irradiation and post-irradiation examination (PIE) experimental data are used in model calibration effort to reduce the inherent uncertainty of simulation results. This paper is focused on fuel temperature predicted by the ABAQUS code’s finite element-based thermal models. The work follows up on a previous study, in which several statistical analysis methods were adapted, implemented in the NGNP Data Management and Analysis System (NDMAS), and applied for improving qualification of AGR-1 thermocouple data. The present work exercises the idea that the abnormal trends of measured data observed from statistical analysis may be caused by either measuring instrument deterioration or physical mechanisms in capsules that may have shifted the system thermal response. As an example, the uneven reduction of the control gas gap in Capsule 5 revealed by the capsule metrology measurements in PIE helps justify the reduction in TC readings instead of TC drift. This in turn prompts modification of thermal model to better fit with experimental data, thus help increase confidence, and in other word reduce model uncertainties in thermal simulation results of the AGR-1 test.

  3. Improving Thermal Model Prediction Through Statistical Analysis of Irradiation and Post-Irradiation Data from AGR Experiments

    SciTech Connect (OSTI)

    Binh T. Pham; Grant L. Hawkes; Jeffrey J. Einerson

    2014-05-01T23:59:59.000Z

    As part of the High Temperature Reactors (HTR) R&D program, a series of irradiation tests, designated as Advanced Gas-cooled Reactor (AGR), have been defined to support development and qualification of fuel design, fabrication process, and fuel performance under normal operation and accident conditions. The AGR tests employ fuel compacts placed in a graphite cylinder shrouded by a steel capsule and instrumented with thermocouples (TC) embedded in graphite blocks enabling temperature control. While not possible to obtain by direct measurements in the tests, crucial fuel conditions (e.g., temperature, neutron fast fluence, and burnup) are calculated using core physics and thermal modeling codes. This paper is focused on AGR test fuel temperature predicted by the ABAQUS code's finite element-based thermal models. The work follows up on a previous study, in which several statistical analysis methods were adapted, implemented in the NGNP Data Management and Analysis System (NDMAS), and applied for qualification of AGR-1 thermocouple data. Abnormal trends in measured data revealed by the statistical analysis are traced to either measuring instrument deterioration or physical mechanisms in capsules that may have shifted the system thermal response. The main thrust of this work is to exploit the variety of data obtained in irradiation and post-irradiation examination (PIE) for assessment of modeling assumptions. As an example, the uneven reduction of the control gas gap in Capsule 5 found in the capsule metrology measurements in PIE helps identify mechanisms other than TC drift causing the decrease in TC readings. This suggests a more physics-based modification of the thermal model that leads to a better fit with experimental data, thus reducing model uncertainty and increasing confidence in the calculated fuel temperatures of the AGR-1 test.

  4. Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics

    SciTech Connect (OSTI)

    Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

    1996-06-01T23:59:59.000Z

    A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation of irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.

  5. Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics

    SciTech Connect (OSTI)

    Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

    1997-05-01T23:59:59.000Z

    A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation after irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.

  6. Status of the NGNP fuel experiment AGR-2 irradiated in the advanced test reactor

    SciTech Connect (OSTI)

    S. Blaine Grover; David A. Petti

    2014-05-01T23:59:59.000Z

    The United States Department of Energy's Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also undergo on-line fission product monitoring to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2), which utilized the same experiment design as well as control and monitoring systems as AGR-1, started irradiation in June 2010 and is currently scheduled to be completed in April 2013. The design of this experiment and sup

  7. Status of the NGNP Fuel Experiment AGR-2 Irradiated in the Advanced Test Reactor

    SciTech Connect (OSTI)

    Blaine Grover

    2012-10-01T23:59:59.000Z

    The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States, and will be irradiated over the next several years to demonstrate and qualify new TRISO coated particle fuel for use in high temperature gas reactors. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which will each consist of at least six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gas will also have on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The first experiment (designated AGR-1) started irradiation in December 2006 and was completed in November 2009. The second experiment (AGR-2), which utilized the same experiment design as well as control and monitoring systems as AGR-1, started irradiation in June 2010 and is currently scheduled to be completed in April 2013. The design of this experiment and support systems will be briefly discussed, followed by the progress and status of the experiment to date.

  8. Global horizontal irradiance clear sky models : implementation and analysis.

    SciTech Connect (OSTI)

    Stein, Joshua S.; Hansen, Clifford W.; Reno, Matthew J.

    2012-03-01T23:59:59.000Z

    Clear sky models estimate the terrestrial solar radiation under a cloudless sky as a function of the solar elevation angle, site altitude, aerosol concentration, water vapor, and various atmospheric conditions. This report provides an overview of a number of global horizontal irradiance (GHI) clear sky models from very simple to complex. Validation of clear-sky models requires comparison of model results to measured irradiance during clear-sky periods. To facilitate validation, we present a new algorithm for automatically identifying clear-sky periods in a time series of GHI measurements. We evaluate the performance of selected clear-sky models using measured data from 30 different sites, totaling about 300 site-years of data. We analyze the variation of these errors across time and location. In terms of error averaged over all locations and times, we found that complex models that correctly account for all the atmospheric parameters are slightly more accurate than other models, but, primarily at low elevations, comparable accuracy can be obtained from some simpler models. However, simpler models often exhibit errors that vary with time of day and season, whereas the errors for complex models vary less over time.

  9. High Temperature Irradiation-Resistant Thermocouple Performance Improvements

    SciTech Connect (OSTI)

    Joshua Daw; Joy Rempe; Darrell Knudson; John Crepeau; S. Curtis Wilkins

    2009-04-01T23:59:59.000Z

    Traditional methods for measuring temperature in-pile degrade at temperatures above 1100 ºC. To address this instrumentation need, the Idaho National Laboratory (INL) developed and evaluated the performance of a high temperature irradiation-resistant thermocouple (HTIR-TC) that contains alloys of molybdenum and niobium. Data from high temperature (up to 1500 ºC) long duration (up to 4000 hours) tests and on-going irradiations at INL’s Advanced Test Reactor demonstrate the superiority of these sensors to commercially-available thermocouples. However, several options have been identified that could further enhance their reliability, reduce their production costs, and allow their use in a wider range of operating conditions. This paper presents results from on-going Idaho National Laboratory (INL)/University of Idaho (UI) efforts to investigate options to improve HTIR-TC ductility, reliability, and resolution by investigating specially-formulated alloys of molybdenum and niobium and alternate diameter thermoelements (wires). In addition, on-going efforts to evaluate alternate fabrication approaches, such as drawn and loose assembly techniques will be discussed. Efforts to reduce HTIR-TC fabrication costs, such as the use of less expensive extension cable will also be presented. Finally, customized HTIR-TC designs developed for specific customer needs will be summarized to emphasize the varied conditions under which these sensors may be used.

  10. The effect of neutron irradiation on silicon carbide fibers

    SciTech Connect (OSTI)

    Newsome, G.A. [Lockheed Martin Corp., Schenectady, NY (United States)

    1997-01-01T23:59:59.000Z

    Nine types of SiC fiber have been exposed to neutron radiation in the Advanced Test Reactor at 250 C for various lengths of time ranging from 83 to 128 days. The effects of these exposures have been initially determined using scanning electron microscopy. The fibers tested were Nicalon{trademark} CG, Tyranno, Hi-Nicalon{trademark}, Dow Corning SiC, Carborundum SiC, Textron SCS-6, polymethysilane (PMS) derived SiC from the University of Michigan, and two types of MER SiC fiber. This covers a range of fibers from widely used commercial fibers to developmental fibers. Consistent with previous radiation experiments, Nicalon fiber was severely degraded by the neutron irradiation. Similarly, Tyranno suffered severe degradation. The more advanced fibers which approach the composition and properties of SiC performed well under irradiation. Of these, the Carborundum SiC fiber appeared to perform the best. The Hi-Nicalon and Dow Corning Fibers exhibited good general stability, but also appear to have some surface roughening. The MER fibers and the Textron SCS-6 fibers both had carbon cores which adversely influenced the overall stability of the fibers.

  11. Method for monitoring irradiated fuel using Cerenkov radiation

    DOE Patents [OSTI]

    Dowdy, E.J.; Nicholson, N.; Caldwell, J.T.

    1980-05-21T23:59:59.000Z

    A method is provided for monitoring irradiated nuclear fuel inventories located in a water-filled storage pond wherein the intensity of the Cerenkov radiation emitted from the water in the vicinity of the nuclear fuel is measured. This intensity is then compared with the expected intensity for nuclear fuel having a corresponding degree of irradiation exposure and time period after removal from a reactor core. Where the nuclear fuel inventory is located in an assembly having fuel pins or rods with intervening voids, the Cerenkov light intensity measurement is taken at selected bright sports corresponding to the water-filled interstices of the assembly in the water storage, the water-filled interstices acting as Cerenkov light channels so as to reduce cross-talk. On-line digital analysis of an analog video signal is possible, or video tapes may be used for later measurement using a video editor and an electrometer. Direct measurement of the Cerenkov radiation intensity also is possible using spot photometers pointed at the assembly.

  12. ON THE EXISTENCE OF SHOCKS IN IRRADIATED EXOPLANETARY ATMOSPHERES

    SciTech Connect (OSTI)

    Heng, Kevin [Institute for Astronomy, ETH Zuerich, Wolfgang-Pauli-Strasse 27, CH-8093 Zuerich (Switzerland)

    2012-12-10T23:59:59.000Z

    Supersonic flows are expected to exist in the atmospheres of irradiated exoplanets, but the question of whether shocks develop lingers. Specifically, it reduces to whether continuous flow in a closed loop may become supersonic and if some portions of the supersonic flow steepen into shocks. We first demonstrate that continuous, supersonic flow may exist in two flavors: isentropic and non-isentropic, with shocks being included in the latter class of solutions. Supersonic flow is a necessary but insufficient condition for shocks to develop. The development of a shock requires the characteristics of neighboring points in a flow to intersect. We demonstrate that the intersection of characteristics may be quantified via the knowledge of the Mach number. Finally, we examine three-dimensional simulations of hot Jovian atmospheres and demonstrate that shock formation is expected to occur mostly on the dayside hemisphere, upstream of the substellar point, because the enhanced temperatures near the substellar point provide a natural pressure barrier for the returning flow. Understanding the role of shocks in irradiated exoplanetary atmospheres is relevant to correctly modeling observables such as the peak offsets of infrared phase curves.

  13. Irradiation testing of a niobium-molybdenum developmental thermocouple

    SciTech Connect (OSTI)

    Knight, R.C.; Greenslade, D.L.

    1991-10-01T23:59:59.000Z

    A need exists for a radiation-resistant thermocouple capable of monitoring temperatures in excess of the limits of the chromel/alumel system. Tungsten/rhenium and platinum/rhodium thermocouples have sufficient temperature capability but have proven to be unstable because of irradiation-induced decalibration. The niobium/molybdenum system is believed to hold great potential for nuclear applications at temperatures up to 2000 K. However, the fragility of pure niobium and fabrication problems with niobium/molybdenum alloys have limited development of this system. Utilizing the Fast Flux Test Facility, a developmental thermocouple with a thermoelement pair consisting of a pure molybdenum and a niobium-1%zirconium alloy wire was irradiated fro 7200 hours at a temperature of 1070 K. The thermocouple performed flawlessly for the duration of the experiment and exhibited stability comparable to a companion chromel/alumel unit. A second thermocouple, operating at 1375 K, is currently being employed to monitor a fusion materials experiment in the Fast Flux Test Facility. This experiment, also scheduled for 7200 hours, will serve to further evaluate the potential of the niobium-1%zirconium/molybdenum thermoelement system. 7 refs., 7 figs.

  14. Janus Experiments: Data from Mouse Irradiation Experiments 1972 - 1989

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    The Janus Experiments, carried out at Argonne National Laboratory from 1972 to 1989 and supported by grants from the US Department of Energy, investigated the effects of neutron and gamma radiation on mouse tissues primarily from B6CF1 mice. 49,000 mice were irradiated: Death records were recorded for 42,000 mice; gross pathologies were recorded for 39,000 mice; and paraffin embedded tissues were preserved for most mice. Mouse record details type and source of radiation [gamma, neutrons]; dose and dose rate [including life span irradiation]; type and presence/absence of radioprotector treatment; tissue/animal morphology and pathology. Protracted low dose rate treatments, short term higher dose rate treatments, variable dose rates with a same total dose, etc. in some cases in conjunction with radioprotectors, were administered. Normal tissues, tumors, metastases were preserved. Standard tissues saved were : lung, liver, spleen, kidney, heart, any with gross lesions (including mammary glands, Harderian gland with eye, adrenal gland, gut, ovaries or testes, brain and pituitary, bone). Data are searchable and specimens can be obtained by request.

  15. Simulation of Electron-Beam Irradiation of Skin Tissue Model

    SciTech Connect (OSTI)

    Miller, John H.; Suleiman, Atef; Chrisler, William B.; Sowa, Marianne B.

    2011-01-03T23:59:59.000Z

    Monte Carlo simulation of electrons stopping in liquid water was used to model the penetration and dose distribution of electron beams incident on the full-thickness EpiDermTM skin model (MatTek, Ashland, VA). This 3D tissue model has a fully developed basement membrane separating an epidermal layer of keratinocytes in various stages of differentiation from a dermal layer of fibroblast embedded in collagen. The simulations were motivated by a desire to selectively expose the epidermal layer to low linear-energy-transfer (LET) radiation in the presence of a non-irradiated dermal layer. Using the variable energy electron microbeam at the Pacific Northwest National Laboratory (PNNL) as a model of device characteristics and irradiation geometry, we find that at the highest beam energy available (90 keV), the estimated 90th percentile of penetration remains in the epidermal layer. To investigate the depth-dose distribution, we calculated lineal energy spectra for 10um thick layers near the 10th, 50th, and 90th percentile of penetration by the 90 keV electron beam. Biphasic spectra showed an increasing component of "stoppers" with increasing depth. Despite changes in the lineal energy spectra, the main effect on dose deposition with increasing depth is the screening effect of tissue above the layer of interest.

  16. Irradiation requirements of Nb3Sn based SC magnets electrical insulation

    E-Print Network [OSTI]

    McDonald, Kirk

    Irradiation requirements of Nb3Sn based SC magnets electrical insulation developed within the Eu electrical insulation candidates · EuCARD insulators certification conditions · Post irradiation tests and neutrino factories will be subjected to very high radiation doses. · The electrical insulation employed

  17. Characterization and In-Situ Ion-Irradiation of MA957 ODS Steel Djamel Kaoumi1

    E-Print Network [OSTI]

    Motta, Arthur T.

    Characterization and In-Situ Ion-Irradiation of MA957 ODS Steel Djamel Kaoumi1 , Arthur Motta1 Laboratory, Argonne, IL 060493, USA INTRODUCTION Oxide dispersion strengthened (ODS) Ferritic. EXPERIMENT Material Characterization Prior to Irradiation MA957 ODS alloy (Fe­14Cr­1Ti­0.3Mo­0.25Y2O3

  18. PublishedbyManeyPublishing(c)IOMCommunicationsLtd Influence of UV irradiation and ozone on

    E-Print Network [OSTI]

    PublishedbyManeyPublishing(c)IOMCommunicationsLtd Influence of UV irradiation and ozone. Kelly*1 The corrosion of Ag in an atmosphere of ozone and humidity with or without irradiation corrosion product to chloride in the reduction solution. The presence of both ozone and UV radiation

  19. Neutron irradiation effects on domain wall mobility and reversibility in lead zirconate titanate thin films

    E-Print Network [OSTI]

    Ferreira, Paulo J.

    changes.1 Damage accumulates when fast neutrons undergo scattering collisions with atomic nuclei resultingNeutron irradiation effects on domain wall mobility and reversibility in lead zirconate titanate://scitation.aip.org/termsconditions. Downloaded to ] IP: 146.6.84.63 On: Wed, 23 Oct 2013 17:34:29 #12;Neutron irradiation effects on domain wall

  20. P5.60B DERIVATION OF DAYLIGHT AND SOLAR IRRADIANCE DATA FROM SATELLITE OBSERVATIONS

    E-Print Network [OSTI]

    Heinemann, Detlev

    P5.60B DERIVATION OF DAYLIGHT AND SOLAR IRRADIANCE DATA FROM SATELLITE OBSERVATIONS A. Hammer, D project SATELLIGHT an attempt is made to use satellite methods to derive daylight and solar irradiance). In daylighting applications, knowledge of the lumi- nance distribution of the sky is of primary concern. Thus

  1. Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy

    E-Print Network [OSTI]

    Engelward, Bevin

    Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene. Irradiated Esophageal Cells are Protected from Radiation- Induced Recombination by MnSOD Gene Therapy. Radiat,a Bevin Engelward,b Michael Epperlya and Joel S. Greenbergera,1 a Departments of Radiation Oncology

  2. channelling investigation of the behaviour of urania under low-energy ion irradiation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    comportement du dioxyde d'uranium irradi´e avec des ions de basse ´energie Directeur de th`ese: Fr before they realize what they can really achieve. His vision on science always motivates me to explore images. He taught me how to polish a sample especially a so fragile material like uranium dioxide

  3. Data-Driven Model for Solar Irradiation Based on Satellite Observations

    E-Print Network [OSTI]

    Anitescu, Mihai

    available at any solar energy production plant. Mathematically, these techniques fall into the categoryData-Driven Model for Solar Irradiation Based on Satellite Observations Ilias Bilionisa , Emil M a data-driven model for solar irradiation based on satellite ob- servations. The model yields

  4. Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation

    E-Print Network [OSTI]

    New Mexico, University of

    Rapid degradation of CdSe/ZnS colloidal quantum dots exposed to gamma irradiation Nathan J. Withers are reported. Optical degradation is evaluated by tracking the dependence of photoluminescence intensity on irradiation dose. CdSe/ZnS quantum dots show poor radiation hardness, and severely degrade after less than 20

  5. Functionally grading the shape memory response in NiTi films: Laser irradiation

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    Functionally grading the shape memory response in NiTi films: Laser irradiation A. J. Birnbaum, G://jap.aip.org/about/rights_and_permissions #12;Functionally grading the shape memory response in NiTi films: Laser irradiation A. J. Birnbaum,a G and mechanism are presented for controlling the shape memory response spatially within monolithic NiTi thin film

  6. 20th century changes in surface solar irradiance in simulations and observations

    E-Print Network [OSTI]

    20th century changes in surface solar irradiance in simulations and observations A. Romanou,1 B December 2006; accepted 5 February 2007; published 8 March 2007. [1] The amount of solar irradiance reaching the surface is a key parameter in the hydrological and energy cycles of the Earth's climate. We

  7. 2013 ISES Solar World Congress Review of satellite-based surface solar irradiation databases for

    E-Print Network [OSTI]

    Recanati, Catherine

    the operating of the solar plant, the same actors along with operators and maintenance companies may need2013 ISES Solar World Congress Review of satellite-based surface solar irradiation databases explores the possibilities provided by satellite-based surface solar irradiation databases

  8. Incident and in situ irradiance in Lakes Cadagno and Lucerne: A comparison of methods and models

    E-Print Network [OSTI]

    Sommaruga, Ruben

    Incident and in situ irradiance in Lakes Cadagno and Lucerne: A comparison of methods and models Key words: Lake Lucerne, Lake Cadagno, PAR, UV-A, UV-B, irradiance regime, radiative transfer models) at the field stations Kastanienbaum at Lake Lucerne (434 m a.s.l.) and Piora at Lake Cadagno (1923 m a

  9. Irradiation and Potassium Sorbate Compared as Preservation Treatments for Atlantic Cod, Gadus morhua

    E-Print Network [OSTI]

    Irradiation and Potassium Sorbate Compared as Preservation Treatments for Atlantic Cod, Gadus for seafood applications pending approval by the U.S. Food and Drug Administration (FDA). Various chemicals of these two seafood preserva- tion methods (irradiation vs. sorbate ABSTRACT-Treatments offresh Atlantic cod

  10. EFFECT OF EXCIMER LASER IRRADIATION OF BIODEGRADABLE POLYMER ON ITS CHEMICAL BONDING

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    EFFECT OF EXCIMER LASER IRRADIATION OF BIODEGRADABLE POLYMER ON ITS CHEMICAL BONDING Paper M1306 profile is favorable for surface treatment. The effects of excimer laser irradiation on the surface to their biocompatibility and biodegradability. Being biodegradable, poly lactic acid (PLA) is used in food packaging

  11. Principal Investigator: Guerrero, Thomas TITLE: Oral antisense oligonucleotides to mitigate GI crypt survival post-irradiation

    E-Print Network [OSTI]

    Warren, Joe

    GI crypt survival post-irradiation A. SPECIFIC AIMS Gastrointestinal (GI) injury is a major cause and contributor of death after whole-body irradiation (Jarrett 1999; NCRP 2001), agents to mitigate the effects of antisense oligonucleotide drugs. Isis Pharmaceuticals was the first to secure Food and Drug Administration

  12. mock fish before in irradiation studies in which we either embedded the inoculum evenly throughout

    E-Print Network [OSTI]

    mock fish before in irradiation studies in which we either embedded the inoculum evenly throughout., AND J. D. KAYLOR. 1977. Variations in the microbial log reduction curves of irradiated cod fillets. The effectiveness of EDTA as a fish preserva- tive. J. Milk Food Technol. 30:277-2B3. WINARINO, F. G., C. R. STUMBO

  13. Irradiation damage of single crystal, coarse-grained, and nanograined copper under helium bombardment at 450 °C

    E-Print Network [OSTI]

    Han, Weizhong

    The irradiation damage behaviors of single crystal (SC), coarse-grained (CG), and nanograined (NG) copper (Cu) films were investigated under Helium (He) ion implantation at 450 °C with different ion fluences. In irradiated ...

  14. Response of 9Cr-ODS Steel to Proton Irradiation at 400 °C

    SciTech Connect (OSTI)

    Jianchao He; Farong Wan; Kumar Sridharan; Todd R. Allen; A. Certain; Y. Q. Wu

    2014-09-01T23:59:59.000Z

    The stability of Y–Ti–O nanoclusters, dislocation structure, and grain boundary segregation in 9Cr-ODS steels has been investigated following proton irradiation at 400 °C with damage levels up to 3.7 dpa. A slight coarsening and a decrease in number density of nanoclusters were observed as a result of irradiation. The composition of nanoclusters was also observed to change with a slight increase of Y and Cr concentration in the nanoclusters following irradiation. Size, density, and composition of the nanoclusters were investigated as a function of nanocluster size, specifically classified to three groups. In addition to the changes in nanoclusters, dislocation loops were observed after irradiation. Finally, radiation-induced enrichment of Cr and depletion of W were observed at grain boundaries after irradiation.

  15. Irradiation effects on base metal and welds of 9Cr-1Mo (EM10) martensitic steel

    SciTech Connect (OSTI)

    Alamo, A.; Seran, J.L.; Rabouille, O.; Brachet, J.C.; Maillard, A.; Touron, H.; Royer, J. [CEA Saclay, Gif-sur-Yvette (France)

    1996-12-31T23:59:59.000Z

    9Cr martensitic steels are being developed for core components (wrapper tubes) of fast breeder reactors as well as for fusion reactor structures. Here, the effects of fast neutron irradiation on the mechanical behavior of base metal and welds of 9Cr-1Mo (EM10) martensitic steel have been studied. Two types of weldments have been produced by TIG and electron beam techniques. Half of samples have been post-weld heat treated to produce a stress-relieved structure. The irradiation has been conducted in the Phenix reactor to doses of 63--65 dpa in the temperature range 450--459 C. The characterization of the welds, before and after irradiation, includes metallographic observations, hardness measurements, tensile and Charpy tests. It is shown that the mechanical properties of the welds after irradiation are in general similar to the characteristics obtained on the base metal, which is little affected by neutron irradiation.

  16. Pb+ irradiation of synthetic zircon (ZrSiO4): Infrared spectroscopic investigation

    SciTech Connect (OSTI)

    Zhang, Ming [University of Cambridge; Boatner, Lynn A [ORNL; Salje, Ekhard K.H. [University of Cambridge; Honda, Shin-ichi [ORNL; Ewing, Rodney C. [University of Michigan

    2008-01-01T23:59:59.000Z

    The structural variations of synthetic zircon (ZrSiO{sub 4}) single crystals irradiated at room temperature by 280 keV Pb{sup +} ions (with fluences up to 1 x 10{sup 15} ions/cm{sup 2}) were investigated using infrared (IR) spectroscopy. Like metamict zircon whose crystal structure is damaged and amorphized by naturally occurring {alpha}-decay events, the Pb{sup +}-irradiated zircon crystals show a dramatic decrease in reflectivity. However, no significant decrease in wavenumbers of the stretching vibrations of SiO{sub 4} tetrahedra in zircon was detected. The Pb{sup +}-implanted zircon exhibits new IR bands, indicating irradiation-induced new vibrations or domains, clusters or phases in addition to SiO{sub 2} and ZrO{sub 2}. IR features consistent with those of Pb silicates (with a divalent state, i.e., Pb{sup 2+}) are also found in the irradiated sample. This finding implies that some of the radiogenic Pb in natural zircon might not actually reside in the zircon lattice or in ZrSiO{sub 4} phases, but form new local domains or clusters. Infrared bands of OH-stretching vibrations were also detected in the irradiated synthetic zircon, which was originally free from OH features prior to the irradiation. These results indicate that H can easily diffuse into the irradiated layer or into irradiated-induced phases to form OH or and hydrous species after the irradiated material is damaged. The type and content of hydrous species vary with irradiation fluences.

  17. Irradiation Alters MMP-2/TIMP-2 System and Collagen Type IV Degradation in Brain

    SciTech Connect (OSTI)

    Lee, Won Hee [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Warrington, Junie P.; Sonntag, William E. [Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Lee, Yong Woo, E-mail: ywlee@vt.edu [School of Biomedical Engineering and Sciences, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States); Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia (United States)

    2012-04-01T23:59:59.000Z

    Purpose: Blood-brain barrier (BBB) disruption is one of the major consequences of radiation-induced normal tissue injury in the central nervous system. We examined the effects of whole-brain irradiation on matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) and extracellular matrix (ECM) degradation in the brain. Methods and Materials: Animals received either whole-brain irradiation (a single dose of 10 Gy {gamma}-rays or a fractionated dose of 40 Gy {gamma}-rays, total) or sham-irradiation and were maintained for 4, 8, and 24 h following irradiation. mRNA expression levels of MMPs and TIMPs in the brain were analyzed by real-time reverse transcriptase-polymerase chain reaction (PCR). The functional activity of MMPs was measured by in situ zymography, and degradation of ECM was visualized by collagen type IV immunofluorescent staining. Results: A significant increase in mRNA expression levels of MMP-2, MMP-9, and TIMP-1 was observed in irradiated brains compared to that in sham-irradiated controls. In situ zymography revealed a strong gelatinolytic activity in the brain 24 h postirradiation, and the enhanced gelatinolytic activity mediated by irradiation was significantly attenuated in the presence of anti-MMP-2 antibody. A significant reduction in collagen type IV immunoreactivity was also detected in the brain at 24 h after irradiation. In contrast, the levels of collagen type IV were not significantly changed at 4 and 8 h after irradiation compared with the sham-irradiated controls. Conclusions: The present study demonstrates for the first time that radiation induces an imbalance between MMP-2 and TIMP-2 levels and suggests that degradation of collagen type IV, a major ECM component of BBB basement membrane, may have a role in the pathogenesis of brain injury.

  18. Standard practice for dosimetry in electron beam and X-Ray (Bremsstrahlung) irradiation facilities for food processing

    E-Print Network [OSTI]

    International Organization for Standardization. Geneva

    2005-01-01T23:59:59.000Z

    Standard practice for dosimetry in electron beam and X-Ray (Bremsstrahlung) irradiation facilities for food processing

  19. Impact of electron irradiation on electron holographic potentiometry

    SciTech Connect (OSTI)

    Park, J. B.; Niermann, T.; Lehmann, M. [Technische Universität Berlin, Institut für Optik und Atomare Physik, Straße des 17. Juni 135, 10623 Berlin (Germany); Berger, D. [Technische Universität Berlin, Zentraleinrichtung für Elektronenmikroskopie, Strae des 17. Juni 135, 10623 Berlin (Germany); Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibnitz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Koslow, I.; Kneissl, M. [Ferdinand-Braun-Institut, Leibnitz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, 10623 Berlin (Germany)

    2014-09-01T23:59:59.000Z

    While electron holography in the transmission electron microscope offers the possibility to measure maps of the electrostatic potential of semiconductors down to nanometer dimensions, these measurements are known to underestimate the absolute value of the potential, especially in GaN. We have varied the dose rates of electron irradiation over several orders of magnitude and observed strong variations of the holographically detected voltages. Overall, the results indicate that the electron beam generates electrical currents within the specimens primarily by the photovoltaic effect and due to secondary electron emission. These currents have to be considered for a quantitative interpretation of electron holographic measurements, as their negligence contributes to large parts in the observed discrepancy between the measured and expected potential values in GaN.

  20. Radiation effects on microstructures and properties of irradiated materials

    SciTech Connect (OSTI)

    Mansur, L.K.

    1996-12-01T23:59:59.000Z

    Development of structural materials to withstand aggressive radiation environments has been carried out on an international scale over the past four decades. Major radiation-induced changes in properties include swelling, creep and embrittlement. The basic work, stimulated by technology, to understand and control these phenomena, has been heavily oriented toward the evolution of microstructures and their effects on properties. Microstructural research has coupled analyses by high resolution techniques with theoretical modeling to describe and predict microscopic features and the resulting macroscopic properties. A short summary is presented of key physical considerations that drive these changes during irradiation. Such processes begin with displacement cascades, and lead to property changes through the diffusion and clustering of defects.

  1. Irradiation behavior of pressurized water reactor control materials

    SciTech Connect (OSTI)

    Demars, R.V.; Dideon, C.G.; Pardue, E.B.S.; Pavinich, W.A.; Thornton, T.A.; Tulenko, J.S.

    1983-07-01T23:59:59.000Z

    Postirradiation examinations have been conducted as part of an extensive Babcock and Wilcox (B and W) program in reactor control materials performance characterization. These examinations of fixed burnable poison rods and control rods confirmed operational performance and extended the material behavior data base for irradiated absorber materials used in B and W-designed pressurized water reactors. These examinations included visual, dimensional, and destructive examinations. They were conducted at B and W's Lynchburg Research Center hot cell facilities on Ag-In-Cd control rods. Al/sub 2/O/sub 3/-B/sub 4/C burnable poison rods, and B/sub 4/C control rods. The visual and dimensional exams revealed no discernible exterior damage on any of these components. Destructive examinations provided data on absorber swelling, gas release, and open porosity.

  2. TEMPERATURE DEPENDANT BEHAVIOUR OBSERVED IN THE AFIP-6 IRRADIATION TEST

    SciTech Connect (OSTI)

    A. B. Robinson; D. M. Wachs; P. Medvedev; S.J. Miller; F. J. Rice; M. K. Meyer; D. M. Perez

    2012-03-01T23:59:59.000Z

    The AFIP-6 test assembly was irradiated for one cycle in the Advanced Test Reactor at Idaho National Laboratory. The experiment was designed to test two monolithic fuel plates at power and burn-ups which bounded the operating conditions of both ATR and HFIR driver fuel. Both plates contained a solid U-Mo fuel foil with a zirconium diffusion barrier between 6061-aluminum cladding plates bonded by hot isostatic pressing. The experiment was designed with an orifice to restrict the coolant flow in order to obtain prototypic coolant temperature conditions. While these coolant temperatures were obtained, the reduced flow resulted in a sufficiently low heat transfer coefficient that failure of the fuel plates occurred. The increased fuel temperature led to significant variations in the fission gas retention behaviour of the U-Mo fuel. These variations in performance are outlined herein.

  3. Fission-product release from irradiated LWR fuel

    SciTech Connect (OSTI)

    Osborne, M.F.; Lorenz, R.A.; Wichner, R.P.

    1982-01-01T23:59:59.000Z

    An experimental investigation of fission product release from commercial LWR fuel under accident conditions is being conducted at Oak Ridge National Laboratory (ORNL). This work, which is sponsored by the US Nuclear Regulatory Commission (NRC), is an extension of earlier experiments up to 1600/sup 0/C and is designed to obtain the experimental data needed to reliably assess the consequences of accidents for fuel temperatures up to melting. The objectives of this program are (1) to determine fission product release rates from fully-irradiated commercial LWR fuel in high-temperature steam; (2) to collect and characterize the aerosol released; (3) to identify the chemical forms of the released material; (4) to correlate the results with related experimental data and develop a consistent source term model; and (5) to aid in the interpretation of tests using simulated LWR fuel.

  4. Issues for Bringing Electron Beam Irradiators On-Line

    SciTech Connect (OSTI)

    Kaye, R.J.; Turman, B.N.

    1999-04-20T23:59:59.000Z

    Irradiation of red meat and poultry has been approved by the U.S. FDA, and the U.S. Department of Agriculture's rule for processing red meat is out for comment. Looking beyond the current issues of packaging materials, labeling, and consumer acceptance, this paper reviews the next step of implementation and how to remove, or at least reduce, the barriers to utilization. Polls of the user community identified their requirements for electron beam or x-ray processing of meat or poultry and their concerns about implementation for on-line processing. These needs and issues are compared to the capabilities of the accelerator industry. The critical issues of beam utilization and dose uniformity, factors affecting floor space requirements, and treatment costs are examined.

  5. Computational study of the generation of crystal defects in a bcc metal target irradiated by short laser pulses

    E-Print Network [OSTI]

    Zhigilei, Leonid V.

    defects in a Cr target irradiated by a short, 200 fs, laser pulse is investigated in computer simulations to the irradiated surface. The stacking faults are unstable and disappear shortly after the laser-induced tensile produced by the short pulse laser irradiation, can result in the confinement of the laser- induced

  6. Use of OCA and APOLLO in Heliosat-4 method for the assessment of surface downwelling solar irradiance

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    the German Aerospace Center (DLR), for the assessment of surface downwelling solar irradiance (SSI). Each-based assessments of surface downwelling solar irradiance (SSI) are more and more used in the domain of solar energy, diffuse and direct surface irradiance for use in various domains: solar energy, biomass, agriculture

  7. High swelling rates observed in neutron-irradiated V-Cr and V-Si binary alloys

    SciTech Connect (OSTI)

    Garner, F.A.; Gelles, D.S. (Pacific Northwest Lab., Richland, WA (United States)); Takahashi, H.; Ohnuki, S.; Kinoshita, H. (Hokkaido Univ., Sapporo (Japan)); Loomis, B.A. (Argonne National Lab., IL (United States))

    1991-11-01T23:59:59.000Z

    Additions of 5 to 14 wt% chromium to vanadium lead to very large swelling rates during neutron irradiation of the binary alloys, with swelling increasing strongly at higher irradiation temperatures. Addition of 2 wt% silicon to vanadium also leads to very large swelling rates but swelling decreases with increasing irradiation temperature. Addition of 1 wt% zirconium does not yield high swelling rates, however.

  8. Mechanism of Irradiation Assisted Cracking of Core Components in Light Water Reactors

    SciTech Connect (OSTI)

    Gary S. Was; Michael Atzmon; Lumin Wang

    2003-04-28T23:59:59.000Z

    The overall goal of the project is to determine the mechanism of irradiation assisted stress corrosion cracking (IASCC). IASCC has been linked to hardening, microstructural and microchemical changes during irradiation. Unfortunately, all of these changes occur simultaneously and at similar rates during irradiation, making attribution of IASCC to any one of these features nearly impossible to determine. The strategy set forth in this project is to develop means to separate microstructural from microchemical changes to evaluate each separately for their effect on IASCC. In the first part, post irradiation annealing (PIA) treatments are used to anneal the irradiated microstructure, leaving only radiation induced segregation (RIS) for evaluation for its contribution to IASCC. The second part of the strategy is to use low temperature irradiation to produce a radiation damage dislocation loop microstructure without radiation induced segregation in order to evaluate the effect of the dislocation microstructure alone. A radiation annealing model was developed based on the elimination of dislocation loops by vacancy absorption. Results showed that there were indeed, time-temperature annealing combinations that leave the radiation induced segregation profile largely unaltered while the dislocation microstructure is significantly reduced. Proton irradiation of 304 stainless steel irradiated with 3.2 MeV protons to 1.0 or 2.5 dpa resulted in grain boundary depletion of chromium and enrichment of nickel and a radiation damaged microstructure. Post irradiation annealing at temperatures of 500 ? 600°C for times of up to 45 min. removed the dislocation microstructure to a greater degree with increasing temperatures, or times at temperature, while leaving the radiation induced segregation profile relatively unaltered. Constant extension rate tensile (CERT) experiments in 288°C water containing 2 ppm O2 and with a conductivity of 0.2 mS/cm and at a strain rate of 3 x 10-7 s-1 showed that the IASCC susceptibility, as measured by the crack length per unit strain, decreased with very short anneals and was almost completely removed by an anneal at 500°C for 45 min. This annealing treatment removed about 15% of the dislocation microstructure and the irradiation hardening, but did not affect the grain boundary chromium depletion or nickel segregation, nor did it affect the grain boundary content of other minor impurities. These results indicate that RIS is not the sole controlling feature of IASCC in irradiated stainless steels in normal water chemistry. The isolation of the irradiated microstructure was approached using low temperature irradiation or combinations of low and high temperature irradiations to achieve a stable, irradiated microstructure without RIS. Experiments were successful in achieving a high degree of irradiation hardening without any evidence of RIS of either major or minor elements. The low temperature irradiations to doses up to 0.3 dpa at T<75°C were also very successful in producing hardening to levels considerably above that for irradiations conducted under nominal conditions of 1 dpa at 360°C. However, the microstructure consisted of an extremely fine dispersion of defect clusters of sizes that are not resolvable by either transmission electron microscopy (TEM) or small angle x-ray scattering (SAXS). The microstructure was not stable at the 288°C IASCC test temperature and resulted in rapid reduction of hardening and presumably, annealing of the defect clusters at this temperature as well. Nevertheless, the annealing studies showed that treatments that resulted in significant decreases in the hardening produced small changes in the dislocation microstructure that were confined to the elimination of the finest of loops (~1 nm). These results substantiate the importance of the very fine defect microstructure in the IASCC process. The results of this program provide the first definitive evidence that RIS is not the sole controlling factor in the irradiation assisted stress corrosion cracking of austenitic stain

  9. High dose rate intraluminal irradiation in recurrent endobronchial carcinoma

    SciTech Connect (OSTI)

    Seagren, S.L.; Harrell, J.H.; Horn, R.A.

    1985-12-01T23:59:59.000Z

    Palliative therapy for previously irradiated patients with symptomatic recurrent endobronchial malignancy is a difficult problem. We have had the opportunity to treat 20 such patients with high dose rate (50-100 rad/min) endobronchial brachytherapy. Eligible patients had received previous high dose thoracic irradiation (TDF greater than or equal to 90), a performance status of greater than or equal to 50, and symptoms caused by a bronchoscopically defined and implantable lesion. The radiation is produced by a small cobalt-60 source (0.7 Ci) remotely afterloaded by cable control. The source is fed into a 4 mm diameter catheter which is placed with bronchoscopic guidance; it may oscillate if necessary to cover the lesion. A dose of 1,000 rad at 1 cm from the source is delivered. We have performed 22 procedures in 20 patients, four following YAG laser debulking. Most had cough, some with hemoptysis. Eight had dyspnea secondary to obstruction and three had obstructive pneumonitis. In 12, symptoms recurred with a mean time to recurrence of 4.3 months (range 1-9 months). Eighteen patients were followed-up and reexamined via bronchoscope 1-2.5 months following the procedure; two were lost to follow-up. All had at least 50 percent clearance of tumor, and six had complete clearance; most regressions were documented on film or videotape. In six, the palliation was durable. The procedure has been well tolerated with no toxicity. We conclude that palliative endobronchial high dose rate brachytherapy is a useful palliative modality in patients with recurrent endobronchial symptomatic carcinoma.

  10. Thermal Analysis of a Uranium Silicide Miniplate Irradiation Experiment

    SciTech Connect (OSTI)

    Donna Post Guillen

    2009-09-01T23:59:59.000Z

    This paper outlines the thermal analysis for the irradiation of high density uranium-silicide (U3Si2 dispersed in an aluminum matrix and clad in aluminum) booster fuel for a Boosted Fast Flux Loop designed to provide fast neutron flux test capability in the ATR. The purpose of this experiment (designated as Gas Test Loop-1 [GTL-1]) is two-fold: (1) to assess the adequacy of the U3Si2/Al dispersion fuel and the aluminum alloy 6061 cladding, and (2) to verify stability of the fuel cladding boehmite pre-treatment at nominal power levels in the 430 to 615 W/cm2 (2.63 to 3.76 Btu/s•in2) range. The GTL-1 experiment relies on a difficult balance between achieving a high heat flux, yet keeping fuel centerline temperature below a specified maximum value throughout an entire operating cycle of the reactor. A detailed finite element model was constructed to calculate temperatures and heat flux levels and to reveal which experiment parameters place constraints on reactor operations. Analyses were performed to determine the bounding lobe power level at which the experiment could be safely irradiated, yet still provide meaningful data under nominal operating conditions. Then, simulations were conducted for nominal and bounding lobe power levels under steady-state and transient conditions with the experiment in the reactor. Reactivity changes due to a loss of commercial power with pump coast-down to emergency flow or a standard in-pile tube pump discharge break were evaluated. The time after shutdown for which the experiment can be adequately cooled by natural convection cooling was determined using a system thermal hydraulic model. An analysis was performed to establish the required in-reactor cooling time prior to removal of the experiment from the reactor. The inclusion of machining tolerances in the numerical model has a large effect on heat transfer.

  11. JOYO-1 Irradiation Test Campaign Technical Close-out, For Information

    SciTech Connect (OSTI)

    G. Borges

    2006-01-31T23:59:59.000Z

    The JOYO-1 irradiation testing was designed to screen the irradiation performance of candidate cladding, structural and reflector materials in support of space reactor development. The JOYO-1 designation refers to the first of four planned irradiation tests in the JOYO reactor. Limited irradiated material performance data for the candidate materials exists for the expected Prometheus-1 duration, fluences and temperatures. Materials of interest include fuel element cladding and core materials (refractory metal alloys and silicon carbide (Sic)), vessel and plant structural materials (refractory metal alloys and nickel-base superalloys), and control and reflector materials (BeO). Key issues to be evaluated were long term microstructure and material property stability. The JOYO-1 test campaign was initiated to irradiate a matrix of specimens at prototypical temperatures and fluences anticipated for the Prometheus-1 reactor [Reference (1)]. Enclosures 1 through 9 describe the specimen and temperature monitors/dosimetry fabrication efforts, capsule design, disposition of structural material irradiation rigs, and plans for post-irradiation examination. These enclosures provide a detailed overview of Naval Reactors Prime Contractor Team (NRPCT) progress in specific areas; however, efforts were in various states of completion at the termination of NRPCT involvement with and restructuring of Project Prometheus.

  12. Cross-sectional TEM Observations of Si Wafers Irradiated With Gas Cluster Ion Beams

    SciTech Connect (OSTI)

    Isogai, Hiromichi; Toyoda, Eiji; Senda, Takeshi; Izunome, Koji [Processing Technology, Silicon Business Group, TOSHIBA CERAMICS CO., LTD. 6-861-5 Higashikou, Seiroumachi Kitakanbaragun, Niigata (Japan); Kashima, Kazuhiko [New Buisness Creation, TOSHIBA CERAMICS CO., LTD. 30 Soya, Hadano City, Kanagawa (Japan); Toyoda, Noriaki; Yamada, Isao [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori, Hyogo (Japan)

    2006-11-13T23:59:59.000Z

    Irradiation by a Gas Cluster Ion Beam (GCIB) is a promising technique for precise surface etching and planarization of Si wafers. However, it is very important to understand the crystalline structure of Si wafers after GCIB irradiation. In this study, the near surface structure of a Si (100) wafer was analyzed after GCIB irradiation, using a cross-sectional transmission electron microscope (XTEM). Ar-GCIB, that physically sputters Si atoms, and SF6-GCIB, that chemically etches the Si surface, were both used. After GCIB irradiation, high temperature annealing was performed in a hydrogen atmosphere. From XTEM observations, the surface of a virgin Si wafer exhibited completely crystalline structures, but the existence of an amorphous Si and a transition layer was confirmed after GCIB irradiation. The thickness of amorphous layer was about 30 nm after Ar-GCIB irradiation at 30 keV. However, a very thin (< 5 nm) layer was observed when 30 keV SF6-GCIB was used. The thickness of the transition layer was the same both Ar and SF6-GCIB irradiation. After annealing, the amorphous Si and transition layers had disappeared, and a complete crystalline structure with an atomically smooth surface was observed.

  13. Simulation of Self-Irradiation of High-Sodium Content Nuclear Waste Glasses

    SciTech Connect (OSTI)

    Pankov, Alexey S.; Ojovan, Michael I. [Immobilisation Science Laboratory, Department of Engineering Materials, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield, S1 3JD (United Kingdom); Batyukhnova, Olga G. [International Education Training Centre, SUE SIA 'Radon', The 7-th Rostovsky Lane 2/14, Moscow, 119121 (Russian Federation); Lee, William E. [Department of Materials, Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ (United Kingdom)

    2007-07-01T23:59:59.000Z

    Alkali-borosilicate glasses are widely used in nuclear industry as a matrix for immobilisation of hazardous radioactive wastes. Durability or corrosion resistance of these glasses is one of key parameters in waste storage and disposal safety. It is influenced by many factors such as composition of glass and surrounding media, temperature, time and so on. As these glasses contain radioactive elements most of their properties including corrosion resistance are also impacted by self-irradiation. The effect of external gamma-irradiation on the short-term (up to 27 days) dissolution of waste borosilicate glasses at moderate temperatures (30 deg. to 60 deg. C) was studied. The glasses studied were Magnox Waste glass used for immobilisation of HLW in UK, and K-26 glass used in Russia for ILW immobilisation. Glass samples were irradiated under {gamma}-source (Co-60) up to doses 1 and 11 MGy. Normalised rates of elemental release and activation energy of release were measured for Na, Li, Ca, Mg, B, Si and Mo before and after irradiation. Irradiation up to 1 MGy results in increase of leaching rate of almost all elements from both MW and K-26 with the exception of Na release from MW glass. Further irradiation up to a dose of 11 MGy leads to the decrease of elemental release rates to nearly initial value. Another effect of irradiation is increase of activation energies of elemental release. (authors)

  14. Oxide shell reduction and magnetic property changes in core-shell Fe nanoclusters under ion irradiation

    SciTech Connect (OSTI)

    Sundararajan, Jennifer A.; Kaur, Maninder; Qiang, You, E-mail: youqiang@uidaho.edu [Department of Physics, University of Idaho, Moscow, Idaho 83844 (United States); Jiang, Weilin [Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352 (United States); McCloy, John S. [School of Mechanical and Materials Engineering, Washington State University, Pullman, Washington 99164 (United States)

    2014-05-07T23:59:59.000Z

    Ion irradiation effects are studied on the Fe-based core-shell nanocluster (NC) films with core as Fe and shell as Fe{sub 3}O{sub 4}/Fe{sub 3}N. These NC films were deposited on Si substrates to thickness of ?0.5 ?m using a NC deposition system. The films were irradiated at room temperature with 5.5?MeV Si{sup 2+} ions to ion fluences of 10{sup 15} and 10{sup 16} ions/cm{sup 2}. It is found that the irradiation induces grain growth, Fe valence reduction in the shell, and crystallization or growth of Fe{sub 3}N. The film retained its Fe-core and its ferromagnetic properties after irradiation. The nature and mechanism of oxide shell reduction and composition dependence after irradiation were studied by synthesizing additional NC films of Fe{sub 3}O{sub 4} and FeO?+?Fe{sub 3}N and irradiating them under the same conditions. The presence of nanocrystalline Fe is found to be a major factor for the oxide shell reduction. The surface morphologies of these films show dramatic changes in the microstructures due to cluster growth and agglomeration as a result of ion irradiation.

  15. The potential application of ultra-nanocrystalline diamond films for heavy ion irradiation detection

    SciTech Connect (OSTI)

    Chen, Huang-Chin [Department of Physics, Tamkang University, Tamsui, New-Taipei, Taiwan 251 (China); Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan, 300 (China); Chen, Shih-Show [Department of Physics, Tamkang University, Tamsui, New-Taipei, Taiwan 251 (China); Department of Information Technology and Mobile Communication, Taipei College of Maritime Technology, Tamsui, New-Taipei, Taiwan 251 (China); Wang, Wei-Cheng; Lin, I-Nan; Chang, Ching-Lin [Department of Physics, Tamkang University, Tamsui, New-Taipei, Taiwan 251 (China); Lee, Chi-Young [Department of Materials Science and Engineering, National Tsing Hua University, Hsinchu, Taiwan, 300 (China); Guo, Jinghua [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2013-06-15T23:59:59.000Z

    The potential of utilizing the ultra-nanocrystalline (UNCD) films for detecting the Au-ion irradiation was investigated. When the fluence for Au-ion irradiation is lower than the critical value (f{sub c}= 5.0 Multiplication-Sign 10{sup 12} ions/cm{sup 2}) the turn-on field for electron field emission (EFE) process of the UNCD films decreased systematically with the increase in fluence that is correlated with the increase in sp{sup 2}-bonded phase ({pi}{sup *}-band in EELS) due to the Au-ion irradiation. The EFE properties changed irregularly, when the fluence for Au-ion irradiation exceeds this critical value. The transmission electron microscopic microstructural examinations, in conjunction with EELS spectroscopic studies, reveal that the structural change preferentially occurred in the diamond-to-Si interface for the samples experienced over critical fluence of Au-ion irradiation, viz. the crystalline SiC phase was induced in the interfacial region and the thickness of the interface decreased. These observations implied that the UNCD films could be used as irradiation detectors when the fluence for Au-ion irradiation does not exceed such a critical value.

  16. Modeling of irradiation embrittlement and annealing/recovery in pressure vessel steels

    SciTech Connect (OSTI)

    Lott, R.G.; Freyer, P.D. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

    1996-12-31T23:59:59.000Z

    The results of reactor pressure vessel (RPV) annealing studies are interpreted in light of the current understanding of radiation embrittlement phenomena in RPV steels. An extensive RPV irradiation embrittlement and annealing database has been compiled and the data reveal that the majority of annealing studies completed to date have employed test reactor irradiated weldments. Although test reactor and power reactor irradiations result in similar embrittlement trends, subtle differences between these two damage states can become important in the interpretation of annealing results. Microstructural studies of irradiated steels suggest that there are several different irradiation-induced microstructural features that contribute to embrittlement. The amount of annealing recovery and the post-anneal re-embrittlement behavior of a steel are determined by the annealing response of these microstructural defects. The active embrittlement mechanisms are determined largely by the irradiation temperature and the material composition. Interpretation and thorough understanding of annealing results require a model that considers the underlying physical mechanisms of embrittlement. This paper presents a framework for the construction of a physically based mechanistic model of irradiation embrittlement and annealing behavior.

  17. Tensile and Charpy impact properties of irradiated reduced-activation ferritic steels

    SciTech Connect (OSTI)

    Klueh, R.L.; Alexander, D.J.

    1996-10-01T23:59:59.000Z

    Tensile tests were conducted on 8 reduced-activation Cr-W steels after irradiation to 15-17 and 26-29 dpa, and Charpy impact tests were conducted on steels irradiated to 26-29 dpa. Irradiation was in Fast Flux Test Facility at 365 C on steels containing 2.25-12% Cr, varying amounts of W, V, and Ta, and 0.1%C. Previously, tensile specimens were irradiated to 6-8 dpa and Charpy specimens to 6-8, 15- 17, and 20-24 dpa. Tensile and Charpy specimens were also thermally aged to 20,000 h at 365 C. Thermal aging had little effect on tensile properties or ductile-brittle transition temperature (DBTT), but several steels showed a slight increase in upper-shelf energy (USE). After 7 dpa, strength increased (hardened) and then remained relatively unchanged through 26-29 dpa (ie, strength saturated with fluence). Post-irradiation Charpy impact tests after 26-29 dpa showed that the loss of impact toughness (increased DBTT, decreased USE) remained relatively unchanged from the values after 20-24 dpa, which had been relatively unchanged from the earlier irradiations. As before, the two 9Cr steels had the most irradiation resistance.

  18. STATUS OF HIGH FLUX ISOTOPE REACTOR IRRADIATION OF SILICON CARBIDE/SILICON CARBIDE JOINTS

    SciTech Connect (OSTI)

    Katoh, Yutai [ORNL; Koyanagi, Takaaki [ORNL; Kiggans, Jim [ORNL; Cetiner, Nesrin [ORNL; McDuffee, Joel [ORNL

    2014-09-01T23:59:59.000Z

    Development of silicon carbide (SiC) joints that retain adequate structural and functional properties in the anticipated service conditions is a critical milestone toward establishment of advanced SiC composite technology for the accident-tolerant light water reactor (LWR) fuels and core structures. Neutron irradiation is among the most critical factors that define the harsh service condition of LWR fuel during the normal operation. The overarching goal of the present joining and irradiation studies is to establish technologies for joining SiC-based materials for use as the LWR fuel cladding. The purpose of this work is to fabricate SiC joint specimens, characterize those joints in an unirradiated condition, and prepare rabbit capsules for neutron irradiation study on the fabricated specimens in the High Flux Isotope Reactor (HFIR). Torsional shear test specimens of chemically vapor-deposited SiC were prepared by seven different joining methods either at Oak Ridge National Laboratory or by industrial partners. The joint test specimens were characterized for shear strength and microstructures in an unirradiated condition. Rabbit irradiation capsules were designed and fabricated for neutron irradiation of these joint specimens at an LWR-relevant temperature. These rabbit capsules, already started irradiation in HFIR, are scheduled to complete irradiation to an LWR-relevant dose level in early 2015.

  19. Does Three-Dimensional External Beam Partial Breast Irradiation Spare Lung Tissue Compared With Standard Whole Breast Irradiation?

    SciTech Connect (OSTI)

    Jain, Anudh K. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States); Vallow, Laura A. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States)], E-mail: vallow.laura@mayo.edu; Gale, Ashley A.; Buskirk, Steven J. [Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida (United States)

    2009-09-01T23:59:59.000Z

    Purpose: To determine whether three-dimensional conformal partial breast irradiation (3D-PBI) spares lung tissue compared with whole breast irradiation (WBI) and to include the biologically equivalent dose (BED) to account for differences in fractionation. Methods and Materials: Radiotherapy treatment plans were devised for WBI and 3D-PBI for 25 consecutive patients randomized on the NSABP B-39/RTOG 0413 protocol at Mayo Clinic in Jacksonville, Florida. WBI plans were for 50 Gy in 25 fractions, and 3D-PBI plans were for 38.5 Gy in 10 fractions. Volume of ipsilateral lung receiving 2.5, 5, 10, and 20 Gy was recorded for each plan. The linear quadratic equation was used to calculate the corresponding dose delivered in 10 fractions and volume of ipsilateral lung receiving these doses was recorded for PBI plans. Ipsilateral mean lung dose was recorded for each plan and converted to BED. Results: There was a significant decrease in volume of lung receiving 20 Gy with PBI (median, 4.4% vs. 7.5%; p < 0.001), which remained after correction for fractionation (median, 5.6% vs. 7.5%; p = 0.02). Mean lung dose was lower for PBI (median, 3.46 Gy vs. 4.57 Gy; p = 0.005), although this difference lost significance after conversion to BED (median, 3.86 Gy{sub 3} vs 4.85 Gy{sub 3}, p = 0.07). PBI plans exposed more lung to 2.5 and 5 Gy. Conclusions: 3D-PBI exposes greater volumes of lung tissue to low doses of radiation and spares the amount of lung receiving higher doses when compared with WBI.

  20. EVALUATION OF U10MO FUEL PLATE IRRADIATION BEHAVIOR VIA NUMERICAL AND EXPERIMENTAL BENCHMARKING

    SciTech Connect (OSTI)

    Samuel J. Miller; Hakan Ozaltun

    2012-11-01T23:59:59.000Z

    This article analyzes dimensional changes due to irradiation of monolithic plate-type nuclear fuel and compares results with finite element analysis of the plates during fabrication and irradiation. Monolithic fuel plates tested in the Advanced Test Reactor (ATR) at Idaho National Lab (INL) are being used to benchmark proposed fuel performance for several high power research reactors. Post-irradiation metallographic images of plates sectioned at the midpoint were analyzed to determine dimensional changes of the fuel and the cladding response. A constitutive model of the fabrication process and irradiation behavior of the tested plates was developed using the general purpose commercial finite element analysis package, Abaqus. Using calculated burn-up profiles of irradiated plates to model the power distribution and including irradiation behaviors such as swelling and irradiation enhanced creep, model simulations allow analysis of plate parameters that are either impossible or infeasible in an experimental setting. The development and progression of fabrication induced stress concentrations at the plate edges was of primary interest, as these locations have a unique stress profile during irradiation. Additionally, comparison between 2D and 3D models was performed to optimize analysis methodology. In particular, the ability of 2D and 3D models account for out of plane stresses which result in 3-dimensional creep behavior that is a product of these components. Results show that assumptions made in 2D models for the out-of-plane stresses and strains cannot capture the 3-dimensional physics accurately and thus 2D approximations are not computationally accurate. Stress-strain fields are dependent on plate geometry and irradiation conditions, thus, if stress based criteria is used to predict plate behavior (as opposed to material impurities, fine micro-structural defects, or sharp power gradients), unique 3D finite element formulation for each plate is required.

  1. Neutron irradiation effects on the ductile-brittle transition of ferritic/martensitic steels

    SciTech Connect (OSTI)

    Klueh, R.L.; Alexander, D.J.

    1997-06-01T23:59:59.000Z

    Ferritic/martensitic steels such as the conventional 9Cr-1MoVNb (Fe-9Cr-1Mo-0.25V-0.06Nb-0.1C) and 12Cr-1MoVW (Fe-12Cr-1Mo-0.25V-0.5W-0.5Ni-0.2C) steels have been considered potential structural materials for future fusion power plants. The major obstacle to their use is embrittlement caused by neutron irradiation. Observations on this irradiation embrittlement will be reviewed. Below 425-450{degrees}C, neutron irradiation hardens the steels. Hardening reduces ductility, but the major effect is an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy, as measured by a Charpy impact test. After irradiation, DBTT values can increase to well above room temperature, thus increasing the chances of brittle rather than ductile fracture. In addition to irradiation hardening, neutrons from the fusion reaction will produce large amounts of helium in the steels used to construct fusion power plant components. Tests to simulate the fusion environment indicate that helium can also affect the toughness. Steels are being developed for fusion applications that have a low DBTT prior to irradiation and then show only a small shift after irradiation. A martensitic 9Cr-2WVTa (nominally Fe-9Cr-2W-0.25V-0.07Ta-0.1C) steel had a much lower DBTT than the conventional 9Cr-1MoVNb steel prior to neutron irradiation and showed a much smaller increase in DBTT after irradiation. 27 refs., 5 figs., 1 tab.

  2. Advanced Gas Reactor (AGR)-5/6/7 Fuel Irradiation Experiments in the Advanced Test Reactor

    SciTech Connect (OSTI)

    A. Joseph Palmer; David A. Petti; S. Blaine Grover

    2014-04-01T23:59:59.000Z

    The United States Department of Energy’s Very High Temperature Reactor (VHTR) Advanced Gas Reactor (AGR) Fuel Development and Qualification Program will be irradiating up to seven separate low enriched uranium (LEU) tri-isotopic (TRISO) particle fuel (in compact form) experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). These irradiations and fuel development are being accomplished to support development of the next generation reactors in the United States. The goals of the irradiation experiments are to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel performance and fission product transport models and codes, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. The experiments, which each consist of at least five separate capsules, are being irradiated in an inert sweep gas atmosphere with individual on-line temperature monitoring and control of each capsule. The sweep gases also have on-line fission product monitoring the effluent from each capsule to track performance of the fuel during irradiation. The first two experiments (designated AGR-1 and AGR-2), have been completed. The third and fourth experiments have been combined into a single experiment designated AGR-3/4, which started its irradiation in December 2011 and is currently scheduled to be completed in April 2014. The design of the fuel qualification experiment, designated AGR-5/6/7, is well underway and incorporates lessons learned from the three previous experiments. Various design issues will be discussed with particular details related to selection of thermometry.

  3. Microstructural examination of V-(4-5%) Cr-(4-5%)Ti irradiated in X530

    SciTech Connect (OSTI)

    Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States); Chung, H.M. [Argonne Natinonal Lab., IL (United States)

    1997-08-01T23:59:59.000Z

    Microstructural examination results are reported for two heats of V-(4-5%)Cr-(4-5%)Ti irradiated in the X530 experiment to {approximately}400{degrees}C to provide an understanding of the microstructural evolution that may be associated with degradation of mechanical properties. Fine precipitates were observed in high density intermixed with small defect clusters for all conditions examined following the irradiation. The irradiation-induced precipitation does not appear to be affected by preirradiation heat treatment at 950-1125{degrees}C. There was no evidence for a significant density of large (diameter >10 nm) dislocation loops or network dislocations.

  4. Predicting Thermal Conductivity Evolution of Polycrystalline Materials Under Irradiation Using Multiscale Approach

    SciTech Connect (OSTI)

    Li, Dongsheng; Li, Yulan; Hu, Shenyang Y.; Sun, Xin; Khaleel, Mohammad A.

    2012-03-01T23:59:59.000Z

    A multiscale methodology was developed to predict the evolution of thermal conductivity of polycrystalline fuel under irradiation. In the mesoscale level, phase field model was used to predict the evolution of gas bubble microstructure. Generation of gas atoms and vacancies were taken into consideration. In the macroscopic scale, a statistical continuum mechanics model was applied to predict the anisotropic thermal conductivity evolution during irradiation. Microstructure predicted by phase field model was fed into statistical continuum mechanics model to predict properties and behavior. Influence of irradiation intensity, exposition time and morphology were investigated. This approach provides a deep understanding on microstructure evolution and property prediction from a basic scientific viewpoint.

  5. Status of the NGNP Graphite Creep Experiments AGC-1 and AGC-2 Irradiated in the Advanced Test Reactor

    SciTech Connect (OSTI)

    Blaine Grover

    2012-10-01T23:59:59.000Z

    The United States Department of Energy’s Next Generation Nuclear Plant (NGNP) Program will be irradiating six nuclear graphite creep experiments in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The graphite experiments will be irradiated over the next six to eight years to support development of a graphite irradiation performance data base on the new nuclear grade graphites now available for use in high temperature gas reactors. The goals of the irradiation experiments are to obtain irradiation performance data, including irradiation creep, at different temperatures and loading conditions to support design of the Next Generation Nuclear Plant (NGNP) Very High Temperature Gas Reactor, as well as other future gas reactors. The experiments will each consist of a single capsule that will contain six peripheral stacks of graphite specimens, with half of the graphite specimens in each stack under a compressive load, while the other half of the specimens will not be subjected to a compressive load during irradiation. The six peripheral stacks will have different compressive loads applied to the top half of each pair of specimen stacks, while a seventh stack will not have a compressive load. The specimens will be irradiated in an inert sweep gas atmosphere with on-line temperature and compressive load monitoring and control. There will also be sampling the sweep gas effluent to determine if any oxidation or off-gassing of the specimens occurs during irradiation of the experiment. The first experiment, AGC-1, started its irradiation in September 2009, and the irradiation was completed in January 2011. The second experiment, AGC-2, started its irradiation in April 2011 and completed its irradiation in May 2012. This paper will briefly discuss the design of the experiment and control systems, and then present the irradiation results for each experiment to date.

  6. Post-Irradiation Fracture Toughness of Unalloyed Molybdenum, ODS molybdenum, and TZM molybdenum following irradiation at 244C to 507C

    SciTech Connect (OSTI)

    Cockeram, Brian V [Bechtel-Bettis, Inc.; Byun, Thak Sang [ORNL; Leonard, Keith J [ORNL; Snead, Lance Lewis [ORNL

    2013-01-01T23:59:59.000Z

    Commercially available unalloyed molybdenum (Low Carbon Arc Cast (LCAC)), Oxide Dispersion Strengthened (ODS) molybdenum, and TZM molybdenum were neutron irradiated at temperatures of nominally 244 C, 407 C, and 509 C to neutron fluences between 1.0 to 4.6x1025 n/m2 (E>0.1 MeV). Post-irradiation fracture toughness testing was performed. All alloys exhibited a Ductile to Brittle Transition Temperature that was defined to occur at 30 4 MPa-m1/2. The highest post-irradiated fracture toughness values (26-107 MPa-m1/2) and lowest DBTT (100-150 C) was observed for ODS molybdenum in the L-T orientation. The finer grain size for ODS molybdenum results in fine laminates that improve the ductile laminate toughening. The results for ODS molybdenum are anisotropic with lower post-irradiated toughness values (20-30 MPa-m1/2) and higher DBTT (450-600 C) in the T-L orientation. The results for T-L ODS molybdenum are consistent or slightly better than those for LCAC molybdenum (21-71 MPa-m1/2 and 450-800 C DBTT). The fracture toughness values measured for LCAC and T-L ODS molybdenum at temperatures below the DBTT were determined to be 8-18 MPa-m1/2. Lower non-irradiated fracture toughness values were measured for TZM molybdenum that are attributed to the large carbide precipitates serving as preferential fracture initiation sites. The role of microstructure and grain size on post-irradiated fracture toughness was evaluated by comparing the results for LCAC molybdenum and ODS molybdenum.

  7. Theoretical and practical implications of the effects of temperature during irradiation and during pre- and post-irradiation storage on the response of thermoluminescence dosimeters

    SciTech Connect (OSTI)

    Gail de Planque, E.

    1984-01-01T23:59:59.000Z

    Experiments have been conducted to determine the applicability of the Randall-Wilkins theory for describing the behavior of CaF/sub 2/:Mn thermoluminescence dosimeters (Harshaw TLD-400 chips). Results were obtained for four different conditions: irradiation followed by storage, irradiation after storage, irradiation both preceded and followed by storage, and continuous simultaneous irradiation and storage. The experiments were performed for storage intervals of approximately 1, 2, 3, 5, 6 and 7 days at five different storage temperatures: -25, +20, +65, +150 and +175/sup 0/C. The results indicate fading that is described not by the Randall-Wilkins theory but rather as a linear function of the logarithm of the storage time. While the results suggest that the trapping efficiency is independent of temperature, they do demonstrate a small decrease in TL response with storage time prior to irradiation which is independent of temperature and time (>17 hours) and hence probably not dosimetric in origin but perhaps optically related. Glow curve analyses support the concept of a band of traps rather than a single trap. The overall results are compared to other data available in the literature most of which is for room-temperature storage. These data, for storage periods ranging from minutes to one year, can also be described as a linear function of the logarithm of the storage time and are remarkably consistent when uniformly normalized. Although peripheral experiments revealed problems associated with self-irradiation as well as a decline in sensitivity with use, the stability experiment results verify the highly favorable stability properties of CaF/sub 2/:Mn for widespread application.

  8. An experience of electron beam (EB) irradiated gemstones in Malaysian nuclear agency

    SciTech Connect (OSTI)

    Idris, Sarada, E-mail: sarada@nuclearmalaysia.gov.my; Hairaldin, Siti Zulaiha, E-mail: sarada@nuclearmalaysia.gov.my; Tajau, Rida, E-mail: sarada@nuclearmalaysia.gov.my; Karim, Jamilah, E-mail: sarada@nuclearmalaysia.gov.my; Jusoh, Suhaimi, E-mail: sarada@nuclearmalaysia.gov.my; Ghazali, Zulkafli, E-mail: sarada@nuclearmalaysia.gov.my [Malaysian Nuclear Agency, Bangi, Selangor (Malaysia); Ahmad, Shamshad [School of Chemicals and Material Engineering, NUST Islamabad (Pakistan)

    2014-02-12T23:59:59.000Z

    In Nuclear Malaysia, a study on gemstone irradiation using beta particle is conducted. The purpose of the study is to evaluate the gemstone colour enhancement by using different kind of precious and non-precious gemstones. By using irradiation technique, selected gemstones are exposed to highly ionizing radiation electron beam to knock off electrons to generate colour centres culminating in the introduction of deeper colours. The colour centres may be stable or unstable depending on the nature of colour centre produced. The colour change of irradiated stones were measured by HunterLab colour measurement. At 50 kGy, Topaz shows changes colour from colourless to golden. Meanwhile pearl shows changes from pale colour to grey. Kunzite and amethyst shows colour changes from colorless to green and pale colour to purple. Gamma survey meter measurement confirmed that irradiation treatment with 3 MeV electron beam machine does not render any activation that activate the gems to become radioactive.

  9. Direct and indirect effects of alpha-particle irradiations of human prostate tumor cells

    E-Print Network [OSTI]

    Wang, Rong, Ph. D. Massachusetts Institute of Technology

    2005-01-01T23:59:59.000Z

    The objective of this project is to establish a model system to study the direct effect, the bystander effect and the combinational effect of alpha-particle irradiations of human prostate tumor cells, toward the goal of ...

  10. Analyzing and simulating the variability of solar irradiance and solar PV powerplants

    E-Print Network [OSTI]

    Lave, Matthew S.

    2012-01-01T23:59:59.000Z

    solar radiation is proportional to PV power output and we use radiant flux density (solar radiation over short timescales also decreased significantly for the averaged irradiance. Power spectral density

  11. THE EFFECTS OF TEMPERATURE AND IMPURITIES ON THE ATOMIC DISPLACEMENT ENERGY DURING ELECTRON IRRADIATION

    E-Print Network [OSTI]

    Drosd, R.M.

    2010-01-01T23:59:59.000Z

    Damage in Copper-Aluminum Alloys III, B. IV. Discussion A.on Displacements in Copper-Aluminum Alloys B. The DamEtgeelectron irradiation of a copper aluminum alloy at cyrogenic

  12. Experimental studies of free defect generation during irradiation: Implications for reactor environments

    SciTech Connect (OSTI)

    Rehn, L.E.; Birtcher, R.C.

    1993-01-01T23:59:59.000Z

    Over the past several years, systematic experiments have revealed that irradiations which generate energetically dense cascades are much less effective than light-ion, MeV electron, or thermal neutron irradiations at producing freely-migrating defects. In this paper, the systematic results on freely-migrating defect production from ion irradiation studies are briefly summarized. Difficulties with applying a simple extrapolation of the ion-irradiation results to neutron environments are discussed. This discussion, coupled with our existing knowledge of neutron-induced property changes, indicates that Compton scattering, and the (n,[gamma]), (n,He) and (n,p) nuclear reactions, are considerably more important for producing freely-migrating defects than was previously realized.

  13. Experimental studies of free defect generation during irradiation: Implications for reactor environments

    SciTech Connect (OSTI)

    Rehn, L.E.; Birtcher, R.C.

    1993-01-01T23:59:59.000Z

    Over the past several years, systematic experiments have revealed that irradiations which generate energetically dense cascades are much less effective than light-ion, MeV electron, or thermal neutron irradiations at producing freely-migrating defects. In this paper, the systematic results on freely-migrating defect production from ion irradiation studies are briefly summarized. Difficulties with applying a simple extrapolation of the ion-irradiation results to neutron environments are discussed. This discussion, coupled with our existing knowledge of neutron-induced property changes, indicates that Compton scattering, and the (n,{gamma}), (n,He) and (n,p) nuclear reactions, are considerably more important for producing freely-migrating defects than was previously realized.

  14. EIS-0017: Fusion Materials Irradiation Testing Facility, Hanford Reservation, Richland, Washington

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy developed this statement to evaluate the environmental impacts associated with proposed construction and operation of an irradiation test facility, the Deuterium-Lithium High Flux Neutron Source Facility, at the Hanford Reservation.

  15. Material Irradiation Damage Studies at BNL BLIP N. Simos and H. Kirk, BNL

    E-Print Network [OSTI]

    McDonald, Kirk

    . furnaces and precision scales) · Photon-spectra (Ge detector) #12;Also, take advantage of the primary-Up addressing Oxidation/Volumetric Change (i.e., tantalum) 1100 deg. C 625 deg. C 20 deg. C #12;Irradiation

  16. Lack of Inflated Radii for Kepler Giant Planet Candidates Receiving Modest Stellar Irradiation

    E-Print Network [OSTI]

    Demory, Brice-Olivier

    The most irradiated transiting hot Jupiters are characterized by anomalously inflated radii, sometimes exceeding Jupiter's size by more than 60%. While different theoretical explanations have been applied, none of them ...

  17. Amorphization of nanocrystalline 3C-SiC irradiated with Si+ ions...

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

    interface and interior amorphization. Citation: Jiang W, H Wang, I Kim, Y Zhang, and WJ Weber.2010."Amorphization of nanocrystalline 3C-SiC irradiated with Si+ ions."Journal of...

  18. Variation in lattice parameters of 6H-SiC irradiated to extremely...

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

    the lattice structure on the basal plane to shrink. Citation: Jiang W, P Nachimuthu, WJ Weber, and L Ginzbursky.2007."Variation in lattice parameters of 6H-SiC irradiated to...

  19. Formation of TiO{sub 2} nanorods by ion irradiation

    SciTech Connect (OSTI)

    Zheng, X. D.; Ren, F., E-mail: fren@whu.edu.cn; Cai, G. X.; Hong, M. Q.; Xiao, X. H.; Wu, W.; Liu, Y. C.; Li, W. Q.; Ying, J. J.; Jiang, C. Z. [School of Physics and Technology, Center for Ion Beam Application and Center for Electron Microscopy, Wuhan University, Wuhan 430072 (China)

    2014-05-14T23:59:59.000Z

    Ion beam irradiation is a powerful method to fabricate and tailor the nanostructured surface of materials. Nanorods on the surface of single crystal rutile TiO{sub 2} were formed by N{sup +} ion irradiation. The dependence of nanorod morphology on ion fluence and energy was elaborated. With increasing ion fluence, nanopores grow in one direction perpendicular to the surface and burst finally to form nanorods. The length of nanorods increases with increasing ion energy under same fluence. The development of the nanorod structure is originated from the formation of the nanopores while N{sub 2} bubbles and aggregation of vacancies were responsible for the formation of nanopores and nanorods. Combining C{sup +} ion irradiation and post-irradiation annealing experiments, two qualitative models are proposed to explain the formation mechanism of these nanorods.

  20. Estimation of the reliability of heterolasers subjected to ageing under irradiation by a fast particle flux

    SciTech Connect (OSTI)

    Bogatov, Alexandr P; Kochetkov, A A; Konyaev, V P

    2011-02-28T23:59:59.000Z

    Relations for estimating the reliability of heterolasers operating under irradiation conditions are calculated based on the probabilistic analysis. The accumulation of defects in their active regions is considered to be the physical cause of their failure. (lasers)