National Library of Energy BETA

Sample records for latitude tilt irradiance

  1. A Method of Correcting for Tilt From Horizontal in Downwelling Shortwave Irradiance Measurements on Moving Platforms

    SciTech Connect (OSTI)

    Long, Charles N.; Bucholtz, Anthony; Jonsson, Haf; Schmid, Beat; Vogelmann, A. M.; Wood, John

    2010-04-14

    Significant errors occur in downwelling shortwave irradiance measurements made on moving platforms due to tilt from horizontal because, when the sun is not completely blocked by overhead cloud, the downwelling shortwave irradiance has a prominent directional component from the direct sun. A-priori knowledge of the partitioning between the direct and diffuse components of the total shortwave irradiance is needed to properly apply a correction for tilt. This partitioning information can be adequately provided using a newly available commercial radiometer that produces reasonable measurements of the total and diffuse shortwave irradiance, and by subtraction the direct shortwave irradiance, with no moving parts and regardless of azimuthal orientation. We have developed methodologies for determining the constant pitch and roll offsets of the radiometers for aircraft applications, and for applying a tilt correction to the total shortwave irradiance data. Results suggest that the methodology is for tilt up to +/-10°, with 90% of the data corrected to within 10 Wm-2 at least for clear-sky data. Without a proper tilt correction, even data limited to 5° of tilt as is typical current practice still exhibits large errors, greater than 100 Wm-2 in some cases. Given the low cost, low weight, and low power consumption of the SPN1 total and diffuse radiometer, opportunities previously excluded for moving platform measurements such as small Unmanned Aerial Vehicles and solar powered buoys now become feasible using our methodology. The increase in measurement accuracy is important, given current concerns over long-term climate variability and change especially over the 70% of the Earth’s surface covered by ocean where long-term records of these measurements are sorely needed and must be made on ships and buoys.

  2. Measurement and modeling of solar irradiance components on horizontal and tilted planes

    SciTech Connect (OSTI)

    Padovan, Andrea; Col, Davide del

    2010-12-15

    In this work new measurements of global and diffuse solar irradiance on the horizontal plane and global irradiance on planes tilted at 20 and 30 oriented due South and at 45 and 65 oriented due East are used to discuss the modeling of solar radiation. Irradiance data are collected in Padova (45.4 N, 11.9 E, 12 m above sea level), Italy. Some diffuse fraction correlations have been selected to model the hourly diffuse radiation on the horizontal plane. The comparison with the present experimental data shows that their prediction accuracy strongly depends on the sky characteristics. The hourly irradiance measurements taken on the tilted planes are compared with the estimations given by one isotropic and three anisotropic transposition models. The use of an anisotropic model, based on a physical description of the diffuse radiation, provides a much better accuracy, especially when measurements of the diffuse irradiance on the horizontal plane are not available and thus transposition models have to be applied in combination with a diffuse fraction correlation. This is particularly significant for the planes oriented away from South. (author)

  3. File:NREL-afg-10km-tilt.pdf | Open Energy Information

    Open Energy Info (EERE)

    tilt.pdf Jump to: navigation, search File File history File usage Afghanistan - Annual Flat Plate Tilted at Latitude Size of this preview: 776 600 pixels. Full resolution...

  4. File:NREL-africa-tilt.pdf | Open Energy Information

    Open Energy Info (EERE)

    tilt.pdf Jump to: navigation, search File File history File usage Africa - Annual Flat Plate Tilted at Latitude (PDF) Size of this preview: 776 600 pixels. Full resolution...

  5. Tilted fuel cell apparatus

    DOE Patents [OSTI]

    Cooper, John F.; Cherepy, Nerine; Krueger, Roger L.

    2005-04-12

    Bipolar, tilted embodiments of high temperature, molten electrolyte electrochemical cells capable of directly converting carbon fuel to electrical energy are disclosed herein. The bipolar, tilted configurations minimize the electrical resistance between one cell and others connected in electrical series. The tilted configuration also allows continuous refueling of carbon fuel.

  6. File:NREL-bhutan-10kmsolar-tilt.pdf | Open Energy Information

    Open Energy Info (EERE)

    File File history File usage Bhutan - Annual - Flat PlateTilted at Latitude Solar Radiation Size of this preview: 776 600 pixels. Full resolution (1,650 1,275 pixels,...

  7. RE-EXAMINING SUNSPOT TILT ANGLE TO INCLUDE ANTI-HALE STATISTICS

    SciTech Connect (OSTI)

    McClintock, B. H.; Norton, A. A.; Li, J. E-mail: aanorton@stanford.edu

    2014-12-20

    Sunspot groups and bipolar magnetic regions (BMRs) serve as an observational diagnostic of the solar cycle. We use Debrecen Photohelographic Data (DPD) from 1974-2014 that determined sunspot tilt angles from daily white light observations, and data provided by Li and Ulrich that determined sunspot magnetic tilt angle using Mount Wilson magnetograms from 1974-2012. The magnetograms allowed for BMR tilt angles that were anti-Hale in configuration, so tilt values ranged from 0 to 360° rather than the more common ±90°. We explore the visual representation of magnetic tilt angles on a traditional butterfly diagram by plotting the mean area-weighted latitude of umbral activity in each bipolar sunspot group, including tilt information. The large scatter of tilt angles over the course of a single cycle and hemisphere prevents Joy's law from being visually identified in the tilt-butterfly diagram without further binning. The average latitude of anti-Hale regions does not differ from the average latitude of all regions in both hemispheres. The distribution of anti-Hale sunspot tilt angles are broadly distributed between 0 and 360° with a weak preference for east-west alignment 180° from their expected Joy's law angle. The anti-Hale sunspots display a log-normal size distribution similar to that of all sunspots, indicating no preferred size for anti-Hale sunspots. We report that 8.4% ± 0.8% of all bipolar sunspot regions are misclassified as Hale in traditional catalogs. This percentage is slightly higher for groups within 5° of the equator due to the misalignment of the magnetic and heliographic equators.

  8. Large optics inspection, tilting, and washing stand

    DOE Patents [OSTI]

    Ayers, Marion Jay; Ayers, Shannon Lee

    2010-08-24

    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.

  9. Large optics inspection, tilting, and washing stand

    DOE Patents [OSTI]

    Ayers, Marion Jay; Ayers, Shannon Lee

    2012-10-09

    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.

  10. An Acoustic Wave Equation for Tilted Transversely Isotropic Media...

    Office of Scientific and Technical Information (OSTI)

    An Acoustic Wave Equation for Tilted Transversely Isotropic Media Citation Details In-Document Search Title: An Acoustic Wave Equation for Tilted Transversely Isotropic Media ...

  11. Spin transport in tilted electron vortex beams

    SciTech Connect (OSTI)

    Basu, Banasri; Chowdhury, Debashree

    2014-12-10

    In this paper we have enlightened the spin related issues of tilted Electron vortex beams. We have shown that in the skyrmionic model of electron we can have the spin Hall current considering the tilted type of electron vortex beam. We have considered the monopole charge of the tilted vortex as time dependent and through the time variation of the monopole charge we can explain the spin Hall effect of electron vortex beams. Besides, with an external magnetic field we can have a spin filter configuration.

  12. Tilt assembly for tracking solar collector assembly

    DOE Patents [OSTI]

    Almy, Charles; Peurach, John; Sandler, Reuben

    2012-01-24

    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.

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

    SciTech Connect (OSTI)

    Dahmen, Tim; Baudoin, Jean-Pierre G; Lupini, Andrew R; Kubel, Christian; Slusallek, Phillip; De Jonge, Niels

    2014-01-01

    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.

  14. Prediction of tilted capillary barrier performance

    SciTech Connect (OSTI)

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

    1997-04-01

    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.; Christensen, Uffe R.

    1984-01-01

    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. ESIF 2015: Bring Us Your Challenges (Book), Energy Systems Integration...

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

    ... New Tools Rooftop Solar Resource Monitoring ... plane-of-array irradiance, latitude-tilt irradiance, back-of- panel PV ... Raytheon and NREL Demonstrate a Microgrid ...

  17. TILT, WARP, AND SIMULTANEOUS PRECESSIONS IN DISKS

    SciTech Connect (OSTI)

    Montgomery, M. M.

    2012-07-10

    Warps are suspected in disks around massive compact objects. However, the proposed warping source-non-axisymmetric radiation pressure-does not apply to white dwarfs. In this Letter, we report the first smoothed particle hydrodynamic simulations of accretion disks in SU UMa-type systems that naturally tilt, warp, and simultaneously precess in the prograde and retrograde directions using white dwarf V344 Lyrae in the Kepler field as our model. After {approx}79 days in V344 Lyrae, the disk angular momentum L{sub d} becomes misaligned to the orbital angular momentum L{sub o} . As the gas stream remains normal to L{sub o} , hydrodynamics (e.g., the lift force) is a likely source to disk tilt. In addition to tilt, the outer disk annuli cyclically change shape from circular to highly eccentric due to tidal torques by the secondary star. The effect of simultaneous prograde and retrograde precession is a warp of the colder, denser midplane as seen along the disk rim. The simulated rate of apsidal advance to nodal regression per orbit nearly matches the observed ratio in V344 Lyrae.

  18. An Acoustic Wave Equation for Tilted Transversely Isotropic Media...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: An Acoustic Wave Equation for Tilted Transversely Isotropic Media A finite-difference method for computing the first arrival traveltimes ...

  19. Reconciliation of local and long range tilt correlations in underdoped...

    Office of Scientific and Technical Information (OSTI)

    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...

  20. Solids irradiator

    DOE Patents [OSTI]

    Morris, Marvin E.; Pierce, Jim D.; Whitfield, Willis J.

    1979-01-01

    A novel facility for irradiation of solids embodying pathogens wherein solids are conveyed through an irradiation chamber in individual containers of an endless conveyor.

  1. Method to fabricate a tilted logpile photonic crystal

    DOE Patents [OSTI]

    Williams, John D.; Sweatt, William C.

    2010-10-26

    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.

  2. Tilted dipole model for bias-dependent photoluminescence pattern

    SciTech Connect (OSTI)

    Fujieda, Ichiro Suzuki, Daisuke; Masuda, Taishi

    2014-12-14

    In a guest-host system containing elongated dyes and a nematic liquid crystal, both molecules are aligned to each other. An external bias tilts these molecules and the radiation pattern of the system is altered. A model is proposed to describe this bias-dependent photoluminescence patterns. It divides the liquid crystal/dye layer into sub-layers that contain electric dipoles with specific tilt angles. Each sub-layer emits linearly polarized light. Its radiation pattern is toroidal and is determined by the tilt angle. Its intensity is assumed to be proportional to the power of excitation light absorbed by the sub-layer. This is calculated by the Lambert-Beer's Law. The absorption coefficient is assumed to be proportional to the cross-section of the tilted dipole moment, in analogy to the ellipsoid of refractive index, to evaluate the cross-section for each polarized component of the excitation light. Contributions from all the sub-layers are added to give a final expression for the radiation pattern. Self-absorption is neglected. The model is simplified by reducing the number of sub-layers. Analytical expressions are derived for a simple case that consists of a single layer with tilted dipoles sandwiched by two layers with horizontally-aligned dipoles. All the parameters except for the tilt angle can be determined by measuring transmittance of the excitation light. The model roughly reproduces the bias-dependent photoluminescence patterns of a cell containing 0.5?wt.?% coumarin 6. It breaks down at large emission angles. Measured spectral changes suggest that the discrepancy is due to self-absorption and re-emission.

  3. Effects of a tilted magnetic field in a Dirac double layer (Journal...

    Office of Scientific and Technical Information (OSTI)

    Effects of a tilted magnetic field in a Dirac double layer Citation Details In-Document Search Title: Effects of a tilted magnetic field in a Dirac double layer Authors: ...

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

    Office of Energy Efficiency and Renewable Energy (EERE)

    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.

  5. 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.; Guo, Q. L.

    2014-05-01

    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.

  6. Automatic recovery of missing amplitudes and phases in tilt-limited...

    Office of Scientific and Technical Information (OSTI)

    Automatic recovery of missing amplitudes and phases in tilt-limited electron crystallography of two-dimensional crystals Citation Details In-Document Search Title: Automatic...

  7. Tissue irradiator

    DOE Patents [OSTI]

    Hungate, F.P.; Riemath, W.F.; Bunnell, L.R.

    1975-12-16

    A tissue irradiator is provided for the in-vivo irradiation of body tissue. The irradiator comprises a radiation source material contained and completely encapsulated within vitreous carbon. An embodiment for use as an in- vivo blood irradiator comprises a cylindrical body having an axial bore therethrough. A radioisotope is contained within a first portion of vitreous carbon cylindrically surrounding the axial bore, and a containment portion of vitreous carbon surrounds the radioisotope containing portion, the two portions of vitreous carbon being integrally formed as a single unit. Connecting means are provided at each end of the cylindrical body to permit connections to blood- carrying vessels and to provide for passage of blood through the bore. In a preferred embodiment, the radioisotope is thulium-170 which is present in the irradiator in the form of thulium oxide. A method of producing the preferred blood irradiator is also provided, whereby nonradioactive thulium-169 is dispersed within a polyfurfuryl alcohol resin which is carbonized and fired to form the integral vitreous carbon body and the device is activated by neutron bombardment of the thulium-169 to produce the beta-emitting thulium-170.

  8. 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; Stevens, Grant M.; Foley, W. Dennis

    2013-12-15

    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

  9. Apparatus for raising or tilting a micromechanical structure

    DOE Patents [OSTI]

    Allen, James J.

    2008-09-09

    An active hinge apparatus is disclosed which can be used to raise a micromechanical structure (e.g. a plate or micromirror) on a substrate. The active hinge apparatus utilizes one or more of teeth protruding outward from an axle which also supports the micromechanical structure on one end thereof. A rack is used to engage the teeth and rotate the axle to raise the micromechanical structure and tilt the structure at an angle to the substrate. Motion of the rack is provided by an actuator which can be a mechanically-powered actuator, or alternately an electrostatic comb actuator or a thermal actuator. A latch can be optionally provided in the active hinge apparatus to lock the micromechanical structure in an "erected" position.

  10. Microelectromechanical apparatus for elevating and tilting a platform

    DOE Patents [OSTI]

    Miller, Samuel Lee; McWhorter, Paul Jackson; Rodgers, Murray Steven; Sniegowski, Jeffry J.; Barnes, Stephen M.

    2003-04-08

    A microelectromechanical (MEM) apparatus is disclosed which has a platform that can be elevated above a substrate and tilted at an arbitrary angle using a plurality of flexible members which support the platform and control its movement. Each flexible member is further controlled by one or more MEM actuators which act to bend the flexible member. The MEM actuators can be electrostatic comb actuators or vertical zip actuators, or a combination thereof. The MEM apparatus can include a mirror coating to form a programmable mirror for redirecting or switching one or more light beams for use in a projection display. The MEM apparatus with the mirror coating also has applications for switching light beams between optical fibers for use in a local area fiber optic network, or for use in fiber optic telecommunications or data communications systems.

  11. Microelectromechanical apparatus for elevating and tilting a platform

    DOE Patents [OSTI]

    Miller, Samuel Lee; McWhorter, Paul Jackson; Rodgers, Murray Steven; Sniegowski, Jeffry J.; Barnes, Stephen M.

    2004-07-06

    A microelectromechanical (MEM) apparatus is disclosed which has a platform that can be elevated above a substrate and tilted at an arbitrary angle using a plurality of flexible members which support the platform and control its movement. Each flexible member is further controlled by one or more MEM actuators which act to bend the flexible member. The MEM actuators can be electrostatic comb actuators or vertical zip actuators, or a combination thereof. The MEM apparatus can include a mirror coating to form a programmable mirror for redirecting or switching one or more light beams for use in a projection display. The MEM apparatus with-the mirror coating also has applications for switching light beams between optical fibers for use in a local area fiber optic network, or for use in fiber optic telecommunications or data communications systems.

  12. The Mid-latitude Continental Convective Clouds (MC3E) Experiment...

    Office of Scientific and Technical Information (OSTI)

    Program Document: The Mid-latitude Continental Convective Clouds (MC3E) Experiment Final Campaign Report Citation Details In-Document Search Title: The Mid-latitude Continental ...

  13. Irradiation subassembly

    DOE Patents [OSTI]

    Seim, O.S.; Filewicz, E.C.; Hutter, E.

    1973-10-23

    An irradiation subassembly for use in a nuclear reactor is described which includes a bundle of slender elongated irradiation -capsules or fuel elements enclosed by a coolant tube and having yieldable retaining liner between the irradiation capsules and the coolant tube. For a hexagonal bundle surrounded by a hexagonal tube the yieldable retaining liner may consist either of six segments corresponding to the six sides of the tube or three angular segments each corresponding in two adjacent sides of the tube. The sides of adjacent segments abut and are so cut that metal-tometal contact is retained when the volume enclosed by the retaining liner is varied and Springs are provided for urging the segments toward the center of the tube to hold the capsules in a closely packed configuration. (Official Gazette)

  14. AN ABSENCE OF FAST RADIO BURSTS AT INTERMEDIATE GALACTIC LATITUDES

    SciTech Connect (OSTI)

    Petroff, E.; Van Straten, W.; Bailes, M.; Barr, E. D.; Coster, P.; Flynn, C.; Keane, E. F.; Johnston, S.; Bates, S. D.; Keith, M. J.; Kramer, M.; Stappers, B. W.; Bhat, N. D. R.; Burgay, M.; Possenti, A.; Tiburzi, C.; Burke-Spolaor, S.; Champion, D.; Ng, C.; Levin, L.; and others

    2014-07-10

    Fast radio bursts (FRBs) are an emerging class of bright, highly dispersed radio pulses. Recent work by Thornton et al. has revealed a population of FRBs in the High Time Resolution Universe (HTRU) survey at high Galactic latitudes. A variety of progenitors have been proposed, including cataclysmic events at cosmological distances, Galactic flare stars, and terrestrial radio frequency interference. Here we report on a search for FRBs at intermediate Galactic latitudes (–15° latitudes. A revised rate estimate or another strong and heretofore unknown selection effect in Galactic latitude would provide closer agreement between the surveys' detection rates. The dearth of detections at low Galactic latitude disfavors a Galactic origin for these bursts.

  15. Method for removing tilt control in adaptive optics systems

    DOE Patents [OSTI]

    Salmon, Joseph Thaddeus

    1998-01-01

    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)

  16. Method for removing tilt control in adaptive optics systems

    DOE Patents [OSTI]

    Salmon, J.T.

    1998-04-28

    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.

  17. Precision tip-tilt-piston actuator that provides exact constraint

    DOE Patents [OSTI]

    Hale, Layton C.

    1999-01-01

    A precision device which can precisely actuate three degrees of freedom of an optic mount, commonly referred to as tip, tilt, and piston. The device consists of three identical flexure mechanisms, an optic mount to be supported and positioned, a structure that supports the flexure mechanisms, and three commercially available linear actuators. The advantages of the precision device is in the arrangement of the constraints offered by the flexure mechanism and not in the particular design of the flexure mechanisms, as other types of mechanisms could be substituted. Each flexure mechanism constrains two degrees of freedom in the plane of the mechanisms and one direction is actuated. All other degrees of freedom are free to move within the range of flexure mechanisms. Typically, three flexure mechanisms are equally spaced in angle about to optic mount and arranged so that each actuated degree of freedom is perpendicular to the plane formed by the optic mount. This arrangement exactly constrains the optic mount and allows arbitrary actuated movement of the plane within the range of the flexure mechanisms. Each flexure mechanism provides a mechanical advantage, typically on the order of 5:1, between the commercially available actuator and the functional point on the optic mount. This improves resolution by the same ratio and stiffness by the square of the ratio.

  18. THEORY OF SOLAR MERIDIONAL CIRCULATION AT HIGH LATITUDES

    SciTech Connect (OSTI)

    Dikpati, Mausumi; Gilman, Peter A. E-mail: gilman@ucar.edu

    2012-02-10

    We build a hydrodynamic model for computing and understanding the Sun's large-scale high-latitude flows, including Coriolis forces, turbulent diffusion of momentum, and gyroscopic pumping. Side boundaries of the spherical 'polar cap', our computational domain, are located at latitudes {>=} 60 Degree-Sign . Implementing observed low-latitude flows as side boundary conditions, we solve the flow equations for a Cartesian analog of the polar cap. The key parameter that determines whether there are nodes in the high-latitude meridional flow is {epsilon} = 2{Omega}n{pi}H{sup 2}/{nu}, where {Omega} is the interior rotation rate, n is the radial wavenumber of the meridional flow, H is the depth of the convection zone, and {nu} is the turbulent viscosity. The smaller the {epsilon} (larger turbulent viscosity), the fewer the number of nodes in high latitudes. For all latitudes within the polar cap, we find three nodes for {nu} = 10{sup 12} cm{sup 2} s{sup -1}, two for 10{sup 13}, and one or none for 10{sup 15} or higher. For {nu} near 10{sup 14} our model exhibits 'node merging': as the meridional flow speed is increased, two nodes cancel each other, leaving no nodes. On the other hand, for fixed flow speed at the boundary, as {nu} is increased the poleward-most node migrates to the pole and disappears, ultimately for high enough {nu} leaving no nodes. These results suggest that primary poleward surface meridional flow can extend from 60 Degree-Sign to the pole either by node merging or by node migration and disappearance.

  19. PROBING THE UNIVERSE'S TILT WITH THE COSMIC INFRARED BACKGROUND DIPOLE

    SciTech Connect (OSTI)

    Fixsen, D. J.; Kashlinsky, A. E-mail: alexander.kashlinsky@nasa.gov

    2011-06-10

    Conventional interpretation of the observed cosmic microwave background (CMB) dipole is that all of it is produced by local peculiar motions. Alternative explanations requiring part of the dipole to be primordial have received support from measurements of large-scale bulk flows. A test of the two hypotheses is whether other cosmic dipoles produced by collapsed structures later than the last scattering coincide with the CMB dipole. One background is the cosmic infrared background (CIB) whose absolute spectrum was measured to {approx}30% by the COBE satellite. Over the 100-500 {mu}m wavelength range its spectral energy distribution can provide a probe of its alignment with the CMB. This is tested with the COBE FIRAS data set which is available for such a measurement because of its low noise and frequency resolution which are important for Galaxy subtraction. Although the FIRAS instrument noise is in principle low enough to determine the CIB dipole, the Galactic foreground is sufficiently close spectrally to keep the CIB dipole hidden. A similar analysis is performed with DIRBE, which-because of the limited frequency coverage-provides a poorer data set. We discuss strategies for measuring the CIB dipole with future instruments to probe the tilt and apply it to the Planck, Herschel, and the proposed Pixie missions. We demonstrate that a future FIRAS-like instrument with instrument noise a factor of {approx}10 lower than FIRAS would make a statistically significant measurement of the CIB dipole. We find that the Planck and Herschel data sets will not allow a robust CIB dipole measurement. The Pixie instrument promises a determination of the CIB dipole and its alignment with either the CMB dipole or the dipole galaxy acceleration vector.

  20. Blue-tilted tensor spectrum and thermal history of the Universe

    SciTech Connect (OSTI)

    Kuroyanagi, Sachiko; Takahashi, Tomo; Yokoyama, Shuichiro E-mail: tomot@cc.saga-u.ac.jp

    2015-02-01

    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.

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

    SciTech Connect (OSTI)

    OToole, A. E-mail: riccardo.desalvo@gmail.com; Pea Arellano, F. E.; Rodionov, A. V.; Kim, C.; Shaner, M.; Asadoor, M.; Sobacchi, E.; Dergachev, V.; DeSalvo, R. E-mail: riccardo.desalvo@gmail.com; Bhawal, A.; Gong, P.; Lottarini, A.; Minenkov, Y.; Murphy, C.

    2014-07-15

    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. Suppression of n=1 Tilt Instability by Magnetic Shaping Coils in Rotamak Plasmas

    SciTech Connect (OSTI)

    Yang, X.; Petrov, Y.; Huang, T. S.

    2009-06-26

    Measurements from the array of Mirnov magnetic coils provide the first evidence for n=1 tilt and radial shift instabilities in a 40 ms field-reversed configuration (FRC) driven by rotating magnetic field. External plasma-shaping magnetic coils are utilized to suppress the n=1 instability modes. It is demonstrated that by energizing the middle shaping coil with 250-500 A current, the tilt mode is completely suppressed when a doublet FRC with an internal figure-of-eight separatrix is formed.

  3. Aerosol optical depth derived from solar radiometry observations at northern mid-latitude sites

    SciTech Connect (OSTI)

    Laulainen, N.S.; Larson, N.R.; Michalsky, J.J.; Harrison, L.C.

    1994-01-01

    Routine, automated solar radiometry observations began with the development of the Mobile Automated Scanning Photometer (MASP) and its installation at the Rattlesnake Mountain Observatory (RMO). We have introduced a microprocessor controlled rotating shadowband radiometer (RSR), both the single detector and the multi-filter/detector (MFRSR) versions to replace the MASP. The operational mode of the RSRs is substantially different than the MASP or other traditional sun-tracking radiometers, because, by virtue of the automated rotating shadowband, the total and diffuse irradiance on a horizontal plane are measured and the direct-normal component deduced through computation from the total and diffuse components by the self-contained microprocessor. Because the three irradiance components are measured using the same detector for a given wavelength, the calibration coefficients are identical for each component, thus reducing errors when comparing them. The MFRSR is the primary radiometric instrument in the nine-station Quantitative Links Network (QLN) established in the eastern United States in late 1991. Data from this network are being used to investigate how cloud- and aerosol-induced radiative effects vary in time and with cloud structure and type over a mid-latitude continental region. This work supports the DOE Quantitative Links Program to quantify linkages between changes in atmospheric composition and climate forcing. In this paper we describe the setup of the QLN and present aerosol optical depth results from the on-going measurements at PNL/RMO, as well as preliminary results from the QLN. From the time-series of data at each site, we compare seasonal variability and geographical differences, as well as the effect of the perturbation to the stratosphere by Mt. Pinatubo. Analysis of the wavelength dependence of optical depth also provides information on the evolution and changes in the size distribution of the aerosols.

  4. SIMULATED FARADAY ROTATION MEASURES TOWARD HIGH GALACTIC LATITUDES

    SciTech Connect (OSTI)

    Akahori, Takuya; Kim, Jongsoo; Ryu, Dongsu; Gaensler, B. M. E-mail: akahori@physics.usyd.edu.au E-mail: ryu@canopus.cnu.ac.kr

    2013-04-20

    We study the Faraday rotation measure (RM) due to the Galactic magnetic field (GMF) toward high Galactic latitudes. The RM arises from the global, regular component as well as from the turbulent, random component of the GMF. We model the former based on observations and the latter using the data of magnetohydrodynamic turbulence simulations. For a large number of different GMF models, we produce mock RM maps around the Galactic poles and calculate various statistical quantities with the RM maps. We find that the observed medians of RMs toward the north and south Galactic poles, {approx}0.0 {+-} 0.5 rad m{sup -2} and {approx} + 6.3 {+-} 0.5 rad m{sup -2}, are difficult to explain with any of our many alternate GMF models. The standard deviation of observed RMs, {approx}9 rad m{sup -2}, is clearly larger than that of simulated RMs. The second-order structure function of observed RMs is substantially larger than that of simulated RMs, especially at small angular scales. We discuss other possible contributions to RM toward high Galactic latitudes. Besides observational errors and the intrinsic RM of background radio sources against which RM is observed, we suggest that the RM due to the intergalactic magnetic field may account for a substantial fraction of the observed RM. Finally, we note that reproducing the observed medians may require additional components or/and structures of the GMF that are not present in our models.

  5. Influences of photosynthetically active radiation on cladode orientation, stem tilting, and height of cacti

    SciTech Connect (OSTI)

    Nobel, P.S.

    1981-08-01

    Stem orientation and morphology were investigated for 14 species of cacti in Chile, Ecuador, Mexico, and the United States. The interception of photosynthetically active radiation (PAR) was specifically considered for cladodes (flattened stems) of platyopuntias, for tilted cylindrical stems, and in the presence of surrounding vegetation.

  6. First results of a polychromatic artificial sodium star for the correction of tilt

    SciTech Connect (OSTI)

    Friedman, H.; Foy, R..; Tallon, M.; Migus, A.

    1996-03-06

    This paper presents the first results of a joint experiment carried out at Lawrence Livermore National Laboratory during January, 1996. Laser and optical systems were tested to provide a polychromatic artificial sodium star for the correction of tilt. This paper presents the results of that experiment.

  7. Exploring a possible origin of a 14 deg y-normal spin tilt at RHIC polarimeter

    SciTech Connect (OSTI)

    Meot, F.; Huang, H.

    2015-06-15

    A possible origin of a 14 deg y-normal spin n0 tilt at the polarimeter is in snake angle defects. This possible cause is investigated by scanning the snake axis angle µ, and the spin rotation angle at the snake, φ, in the vicinity of their nominal values.

  8. Selection of a numerical unsaturated flow code for tilted capillary barrier performance evaluation

    SciTech Connect (OSTI)

    Webb, S.W. [Sandia National Labs., Albuquerque, NM (United States). Geohydrology Dept.

    1996-09-01

    Capillary barriers consisting of tilted fine-over-coarse layers have been suggested as landfill covers as a means to divert water infiltration away from sensitive underground regions under unsaturated flow conditions, especially for arid and semi-arid regions. Typically, the HELP code is used to evaluate landfill cover performance and design. Unfortunately, due to its simplified treatment of unsaturated flow and its essentially one-dimensional nature, HELP is not adequate to treat the complex multidimensional unsaturated flow processes occurring in a tilted capillary barrier. In order to develop the necessary mechanistic code for the performance evaluation of tilted capillary barriers, an efficient and comprehensive unsaturated flow code needs to be selected for further use and modification. The present study evaluates a number of candidate mechanistic unsaturated flow codes for application to tilted capillary barriers. Factors considered included unsaturated flow modeling, inclusion of evapotranspiration, nodalization flexibility, ease of modification, and numerical efficiency. A number of unsaturated flow codes are available for use with different features and assumptions. The codes chosen for this evaluation are TOUGH2, FEHM, and SWMS{_}2D. All three codes chosen for this evaluation successfully simulated the capillary barrier problem chosen for the code comparison, although FEHM used a reduced grid. The numerical results are a strong function of the numerical weighting scheme. For the same weighting scheme, similar results were obtained from the various codes. Based on the CPU time of the various codes and the code capabilities, the TOUGH2 code has been selected as the appropriate code for tilted capillary barrier performance evaluation, possibly in conjunction with the infiltration, runoff, and evapotranspiration models of HELP. 44 refs.

  9. Microsoft Word - Tilted-Rig-TP-Definition-Version1-Aug-14-2012A.doc

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

    Test Problem: Tilted Rayleigh-Taylor for 2-D Mixing Studies Authors: Malcolm J. Andrews (XCP-4, LANL), 505-606-1430, mandrews@lanl.gov David L. Youngs (AWE) , david.youngs@awe.co.uk Daniel Livescu (CCS-2, LANL), 505-665-1758, livescu@lanl.gov Date: August 10, 2012 Version: 1.0 LA-UR: 12-24091 Contents 1. Introduction................................................................................................................................. 2 2. Problem definition

  10. Cosmological signatures of tilted isocurvature perturbations: reionization and 21cm fluctuations

    SciTech Connect (OSTI)

    Sekiguchi, Toyokazu; Sugiyama, Naoshi; Tashiro, Hiroyuki; Silk, Joseph E-mail: hiroyuki.tashiro@asu.edu E-mail: naoshi@nagoya-u.jp

    2014-03-01

    We investigate cosmological signatures of uncorrelated isocurvature perturbations whose power spectrum is blue-tilted with spectral index 2?tilted isocurvature primordial power spectrum. We also study the consequences for 21cm line fluctuations due to neutral hydrogens in minihalos. Combination of measurements of the reionization optical depth and 21cm line fluctuations will provide complementary probes of a highly blue-tilted isocurvature power spectrum.

  11. Effects of the scatter in sunspot group tilt angles on the large-scale magnetic field at the solar surface

    SciTech Connect (OSTI)

    Jiang, J.; Cameron, R. H.; Schüssler, M.

    2014-08-10

    The tilt angles of sunspot groups represent the poloidal field source in Babcock-Leighton-type models of the solar dynamo and are crucial for the build-up and reversals of the polar fields in surface flux transport (SFT) simulations. The evolution of the polar field is a consequence of Hale's polarity rules, together with the tilt angle distribution which has a systematic component (Joy's law) and a random component (tilt-angle scatter). We determine the scatter using the observed tilt angle data and study the effects of this scatter on the evolution of the solar surface field using SFT simulations with flux input based upon the recorded sunspot groups. The tilt angle scatter is described in our simulations by a random component according to the observed distributions for different ranges of sunspot group size (total umbral area). By performing simulations with a number of different realizations of the scatter we study the effect of the tilt angle scatter on the global magnetic field, especially on the evolution of the axial dipole moment. The average axial dipole moment at the end of cycle 17 (a medium-amplitude cycle) from our simulations was 2.73 G. The tilt angle scatter leads to an uncertainty of 0.78 G (standard deviation). We also considered cycle 14 (a weak cycle) and cycle 19 (a strong cycle) and show that the standard deviation of the axial dipole moment is similar for all three cycles. The uncertainty mainly results from the big sunspot groups which emerge near the equator. In the framework of Babcock-Leighton dynamo models, the tilt angle scatter therefore constitutes a significant random factor in the cycle-to-cycle amplitude variability, which strongly limits the predictability of solar activity.

  12. Octahedral tilt transitions in the relaxor ferroelectric Na{sub 1/2}Bi{sub 1/2}TiO{sub 3}

    SciTech Connect (OSTI)

    Meyer, Kai-Christian Gröting, Melanie; Albe, Karsten

    2015-07-15

    The kinetics of octahedral tilt transitions in the lead-free relaxor material sodium bismuth titanate Na{sub 1/2}Bi{sub 1/2}TiO{sub 3} (NBT) is investigated by electronic structure calculations within density functional theory. Energy barriers for transitions between tetragonal, rhombohedral and orthorhombic tilts in cation configurations with [001]- and [111]-order on the A-sites are determined by nudged elastic band calculations. By tilting entire layers of octahedra simultaneously we find that the activation energy is lower for structures with 001-order compared to such with 111-order. The energetic coupling between differently tilted layers is, however, negligibly small. By introducing a single octahedral defect we create local tilt disorder and find that the deformation energy of the neighboring octahedra is less in a rhombohedral than in a tetragonal structure. By successively increasing the size of clusters of orthorhombic defects in a rhombohedral matrix with 001-order, we determine a critical cluster size of about 40 Å . Thus groups of about ten octahedra can be considered as nuclei for polar nanoregions, which are the cause of the experimentally observed relaxor behavior of NBT. - Graphical abstract: Nine orthorhombic oxygen octahedral tilt defects in a rhombohedral tilt configuration. - Highlights: • Chemical order influences energy barriers of octahedral tilt transitions. • The octahedral deformation energy is lower in rhombohedral phases. • Tilt defect clusters are more likely in rhombohedral structures. • Tilt defect clusters can act as nuclei for polar nanoregions.

  13. Entanglement, avoided crossings, and quantum chaos in an Ising model with a tilted magnetic field

    SciTech Connect (OSTI)

    Karthik, J.; Sharma, Auditya; Lakshminarayan, Arul [Department of Physics, Indian Institute of Technology Madras, Chennai 600036 (India)

    2007-02-15

    We study a one-dimensional Ising model with a magnetic field and show that tilting the field induces a transition to quantum chaos. We explore the stationary states of this Hamiltonian to show the intimate connection between entanglement and avoided crossings. In general, entanglement gets exchanged between the states undergoing an avoided crossing with an overall enhancement of multipartite entanglement at the closest point of approach, simultaneously accompanied by diminishing two-body entanglement as measured by concurrence. We find that both for stationary as well as nonstationary states, nonintegrability leads to a destruction of two-body correlations and distributes entanglement more globally.

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

    SciTech Connect (OSTI)

    Zhang, Zhelin; Chen, Yanping Yang, Liu; Yuan, Xiaohui; Liu, Feng; Chen, Min; Xu, Jianqiu; Zhang, Jie; Sheng, Zhengming

    2014-09-08

    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.

  15. MASSIVE LEAKAGE IRRADIATOR

    DOE Patents [OSTI]

    Wigner, E.P.; Szilard, L.; Christy, R.F.; Friedman, F.L.

    1961-05-30

    An irradiator designed to utilize the neutrons that leak out of a reactor around its periphery is described. It avoids wasting neutron energy and reduces interference with the core flux to a minimum. This is done by surrounding all or most of the core with removable segments of the material to be irradiated within a matrix of reflecting material.

  16. Comminuting irradiated ferritic steel

    DOE Patents [OSTI]

    Bauer, Roger E.; Straalsund, Jerry L.; Chin, Bryan A.

    1985-01-01

    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.

  17. Irradiation Creep in Graphite

    SciTech Connect (OSTI)

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13

    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.

  18. Thermal conductivity of Bi{sub 2}Te{sub 3} tilted nanowires, a molecular dynamics study

    SciTech Connect (OSTI)

    Li, Shen Lacroix, David; Termentzidis, Konstantinos; Chaput, Laurent; Stein, Nicolas; Frantz, Cedric

    2015-06-08

    Evidence for an excellent compromise between structural stability and low thermal conductivity has been achieved with tilted Bi{sub 2}Te{sub 3} nanowires. The latter ones were recently fabricated and there is a need in modeling and characterization. The structural stability and the thermal conductivity of Bi{sub 2}Te{sub 3} nanowires along the tilted [015]* direction and along the [010] direction have been explored. For the two configurations of nanowires, the effect of the length and the cross section on the thermal conductivity is discussed. The thermal conductivity of infinite size tilted nanowire is 0.34?W/m K, significantly reduced compared to nanowire along the [010] direction (0.59?W/m K). This reveals that in Bi{sub 2}Te{sub 3} nanowires the structural anisotropy can be as important as size effects to reduce the thermal conductivity. The main reason is the reduction of the phonon mean free path which is found to be 1.7?nm in the tilted nanowires, compared to 5.3?nm for the nanowires along the [010] direction. The fact that tilted Bi{sub 2}Te{sub 3} nanowire is mechanically stable and it has extremely low thermal conductivity suggests these nanowires as a promising material for future thermoelectric generation application.

  19. THE TRANSIT INGRESS AND THE TILTED ORBIT OF THE EXTRAORDINARILY ECCENTRIC EXOPLANET HD 80606b

    SciTech Connect (OSTI)

    Winn, Joshua N.; Howard, Andrew W.; Marcy, Geoffrey W.; Johnson, John Asher; Gazak, J. Zachary; Starkey, Donn; Ford, Eric B.; Colon, Knicole D.; Reyes, Francisco; Nortmann, Lisa; Dreizler, Stefan; Odewahn, Stephen; Welsh, William F.; Kadakia, Shimonee; Vanderbei, Robert J.; Adams, Elisabeth R.; Lockhart, Matthew; Crossfield, Ian J.; Valenti, Jeff A.; Dantowitz, Ronald

    2009-10-01

    We present the results of a transcontinental campaign to observe the 2009 June 5 transit of the exoplanet HD 80606b. We report the first detection of the transit ingress, revealing the transit duration to be 11.64 +- 0.25 hr and allowing more robust determinations of the system parameters. Keck spectra obtained at midtransit exhibit an anomalous blueshift, giving definitive evidence that the stellar spin axis and planetary orbital axis are misaligned. The Keck data show that the projected spin-orbit angle lambda is between 32 deg. and 87 deg. with 68.3% confidence and between 14 deg. and 142 deg. with 99.73% confidence. Thus, the orbit of this planet is not only highly eccentric (e = 0.93) but is also tilted away from the equatorial plane of its parent star. A large tilt had been predicted, based on the idea that the planet's eccentric orbit was caused by the Kozai mechanism. Independently of the theory, it is worth noting that all three exoplanetary systems with known spin-orbit misalignments have massive planets on eccentric orbits, suggesting that those systems migrate through a different channel than lower mass planets on circular orbits.

  20. Observation of tilting activities in translated field reversed configuration plasma using computer tomography at two different cross sections

    SciTech Connect (OSTI)

    Yoshimura, Satoru; Sugimoto, Satoshi; Okada, Shigefumi

    2007-11-15

    Tilting activities of field reversed configuration (FRC) plasma were observed in translation experiments using computer tomography (CT) at two different cross sections in the FRC injection experiment (FIX) machine [S. Okada et al., Nucl. Fusion 47, 677 (2007)]. In these experiments, two sets of CT devices were installed at the upstream and downstream sides of the confinement chamber of the FIX. Each CT device was composed of three arrays of detectors sensitive to the near-infrared radiation. The peak of the reconstructed emission profile at one side was displaced from the center of the cross section of the chamber. On the other hand, the reconstructed profile at the other side was located around the center. This result suggests that the FRC plasma was tilting in the axial direction. The occurrence of the observed tilting activities had almost no effect on the lifetime of the FRC plasma.

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

    DOE Patents [OSTI]

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

    2005-11-01

    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.

  2. Bose-Einstein condensates on tilted lattices: Coherent, chaotic, and subdiffusive dynamics

    SciTech Connect (OSTI)

    Kolovsky, Andrey R.; Gomez, Edgar A.; Korsch, Hans Juergen

    2010-02-15

    The dynamics of a (quasi-) one-dimensional interacting atomic Bose-Einstein condensate in a tilted optical lattice is studied in a discrete mean-field approximation, i.e., in terms of the discrete nonlinear Schroedinger equation. If the static field is varied, the system shows a plethora of dynamical phenomena. In the strong field limit, we demonstrate the existence of (almost) nonspreading states which remain localized on the lattice region populated initially and show coherent Bloch oscillations with fractional revivals in the momentum space (so-called quantum carpets). With decreasing field, the dynamics becomes irregular, however, still confined in configuration space. For even weaker fields, we find subdiffusive dynamics with a wave-packet width growing as t{sup 1/4}.

  3. Test Problem: Tilted Rayleigh-Taylor for 2-D Mixing Studies

    SciTech Connect (OSTI)

    Andrews, Malcolm J.; Livescu, Daniel; Youngs, David L.

    2012-08-14

    The 'tilted-rig' test problem originates from a series of experiments (Smeeton & Youngs, 1987, Youngs, 1989) performed at AWE in the late 1980's, that followed from the 'rocket-rig' experiments (Burrows et al., 1984; Read & Youngs, 1983), and exploratory experiments performed at Imperial College (Andrews, 1986; Andrews and Spalding, 1990). A schematic of the experiment is shown in Figure 1, and comprises a tank filled with light fluid above heavy, and then 'tilted' on one side of the apparatus, thus causing an 'angled interface' to the acceleration history due to rockets. Details of the configuration given in the next chapter include: fluids, dimensions, and other necessary details to simulate the experiment. Figure 2 shows results from two experiments, Case 110 (which is the source for this test problem) that has an Atwood number of 0.5, and Case 115 (a secondary source described in Appendix B), with Atwood of 0.9 Inspection of the photograph in Figure 2 (the main experimental diagnostic) for Case 110. reveals two main areas for mix development; 1) a large-scale overturning motion that produces a rising plume (spike) on the left, and falling plume (bubble) on the right, that are almost symmetric; and 2) a Rayleigh-Taylor driven mixing central mixing region that has a large-scale rotation associated with the rising and falling plumes, and also experiences lateral strain due to stretching of the interface by the plumes, and shear across the interface due to upper fluid moving downward and to the right, and lower fluid moving upward and to the left. Case 115 is similar but differs by a much larger Atwood of 0.9 that drives a strong asymmetry between a left side heavy spike penetration and a right side light bubble penetration. Case 110 is chosen as the source for the present test problem as the fluids have low surface tension (unlike Case 115) due the addition of a surfactant, the asymmetry small (no need to have fine grids for the spike), and there is extensive

  4. Characteristics of optical emissions and particle precipitation in mid/low-latitude aurorae

    SciTech Connect (OSTI)

    Rassoul K., H.R.

    1987-01-01

    Ground-based optical observations have been made at low/mid latitudes to study the auroral effects of particle precipitation. The measured optical emissions include (OI) 5577 {Angstrom}, (OI) 6300 {Angstrom}, and (OI) 7774 {Angstrom} of atomic oxygen, the Balmer-{beta} line of Hydrogen at 4861 {Angstrom}; and the emission bands from the first negative nitrogen system at 3914 {Angstrom} and 4278 {Angstrom}. Spectral characteristics of low-latitude aurorae, the correlation of optical data with geomagnetic field variations, and the nature of the precipitating particles were established. The observed auroral emissions have characteristics appropriate to the precipitation into the thermosphere of heavy energetic (keV energy) particles and/or electrons of energy of the order of eV rather than the keV electron precipitation as in the high-latitude auroral zone. The latitude variation of optical emissions shows a strong increase from low to mid latitudes, and the strongest emissions occur in the evening to midnight local time period. The particle precipitation enhances at times when there is a populated and/or energized ring current and there exists a strong magnetic perturbation near the local meridian of the precipitation.

  5. Uranium vacancy mobility at the Σ5 symmetric tilt and Σ5 twist grain boundaries in UO₂

    SciTech Connect (OSTI)

    Uberuaga, Blas Pedro; Andersson, David A.

    2015-10-01

    Ionic transport at grain boundaries in oxides dictates a number of important phenomena, from ionic conductivity to sintering to creep. For nuclear fuels, it also influences fission gas bubble nucleation and growth. Here, using a combination of atomistic calculations and object kinetic Monte Carlo (okMC) simulations, we examine the kinetic pathways associated with uranium vacancies at two model grain boundaries in UO2. The barriers for vacancy motion were calculated using the nudged elastic band method at all uranium sites at each grain boundary and were used as the basis of the okMC simulations. For both boundaries considered – a simple tilt and a simple twist boundary – the mobility of uranium vacancies is significantly higher than in the bulk. For the tilt boundary, there is clearly preferred migration along the tilt axis as opposed to in the perpendicular direction while, for the twist boundary, migration is essentially isotropic within the boundary plane. These results show that cation defect mobility in fluorite-structured materials is enhanced at certain types of grain boundaries and is dependent on the boundary structure with the tilt boundary exhibiting higher rates of migration than the twist boundary.

  6. Uranium vacancy mobility at the Σ5 symmetric tilt and Σ5 twist grain boundaries in UO₂

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

    Uberuaga, Blas Pedro; Andersson, David A.

    2015-10-01

    Ionic transport at grain boundaries in oxides dictates a number of important phenomena, from ionic conductivity to sintering to creep. For nuclear fuels, it also influences fission gas bubble nucleation and growth. Here, using a combination of atomistic calculations and object kinetic Monte Carlo (okMC) simulations, we examine the kinetic pathways associated with uranium vacancies at two model grain boundaries in UO2. The barriers for vacancy motion were calculated using the nudged elastic band method at all uranium sites at each grain boundary and were used as the basis of the okMC simulations. For both boundaries considered – a simplemore » tilt and a simple twist boundary – the mobility of uranium vacancies is significantly higher than in the bulk. For the tilt boundary, there is clearly preferred migration along the tilt axis as opposed to in the perpendicular direction while, for the twist boundary, migration is essentially isotropic within the boundary plane. These results show that cation defect mobility in fluorite-structured materials is enhanced at certain types of grain boundaries and is dependent on the boundary structure with the tilt boundary exhibiting higher rates of migration than the twist boundary.« less

  7. Evaluation of models for estimating solar irradiation on vertical surfaces at Valencia, Spain

    SciTech Connect (OSTI)

    Utrillas, M.P.; Martinez-Lozano, J.A.; Casanovas, A.J. )

    1991-01-01

    Hourly irradiation data recorded on vertical surfaces at north, east, south, and west orientations during the winter period going from December 1989 to March 1990 in Valencia, Spain, have been compared with estimated solar irradiation from several tilted-surface models. The isotropic-, Temps' and Coulson's-, Klucher's-, Hay's-, Shartveit's and Olseth's, Gueymard's-, and Perez' (simplified) models have been considered for this comparison. Root-mean-square-difference (RMSD), mean-bias-difference (MBD) and mean-absolute-difference (MAD) estimators have been used to measure the departure of models from experimental data. Modeled values are evaluated with the original coefficients proposed by the authors. Results of comparison show that the south orientation is less prone to modeling errors. Perez' 25{degree} circumsolar simplified model being the less affected by errors in north, eat and south orientations; for west orientation Klucher's model gives a lesser error. These results are consistent with those reported in previous studies.

  8. FOOD IRRADIATION REACTOR

    DOE Patents [OSTI]

    Leyse, C.F.; Putnam, G.E.

    1961-05-01

    An irradiation apparatus is described. It comprises a pressure vessel, a neutronic reactor active portion having a substantially greater height than diameter in the pressure vessel, an annular tank surrounding and spaced from the pressure vessel containing an aqueous indium/sup 1//sup 1//sup 5/ sulfate solution of approximately 600 grams per liter concentration, means for circulating separate coolants through the active portion and the space between the annular tank and the pressure vessel, radiator means adapted to receive the materials to be irradiated, and means for flowing the indium/sup 1//sup 1//sup 5/ sulfate solution through the radiator means.

  9. Fuel or irradiation subassembly

    DOE Patents [OSTI]

    Seim, O.S.; Hutter, E.

    1975-12-23

    A subassembly for use in a nuclear reactor is described which incorporates a loose bundle of fuel or irradiation pins enclosed within an inner tube which in turn is enclosed within an outer coolant tube and includes a locking comb consisting of a head extending through one side of the inner sleeve and a plurality of teeth which extend through the other side of the inner sleeve while engaging annular undercut portions in the bottom portion of the fuel or irradiation pins to prevent movement of the pins.

  10. NSUF Irradiated Materials Library

    SciTech Connect (OSTI)

    Cole, James Irvin

    2015-09-01

    The Nuclear Science User Facilities has been in the process of establishing an innovative Irradiated Materials Library concept for maximizing the value of previous and on-going materials and nuclear fuels irradiation test campaigns, including utilization of real-world components retrieved from current and decommissioned reactors. When the ATR national scientific user facility was established in 2007 one of the goals of the program was to establish a library of irradiated samples for users to access and conduct research through competitively reviewed proposal process. As part of the initial effort, staff at the user facility identified legacy materials from previous programs that are still being stored in laboratories and hot-cell facilities at the INL. In addition other materials of interest were identified that are being stored outside the INL that the current owners have volunteered to enter into the library. Finally, over the course of the last several years, the ATR NSUF has irradiated more than 3500 specimens as part of NSUF competitively awarded research projects. The Logistics of managing this large inventory of highly radioactive poses unique challenges. This document will describe materials in the library, outline the policy for accessing these materials and put forth a strategy for making new additions to the library as well as establishing guidelines for minimum pedigree needed to be included in the library to limit the amount of material stored indefinitely without identified value.

  11. Calculation of Latitude and Longitude for Points on Perimeter of a Circle on a Sphere

    SciTech Connect (OSTI)

    Morris, Heidi E.

    2015-08-14

    This document describes the calculation of the Earth-Centered Earth Fixed (ECEF) coordinates for points lying on the perimeter of a circle. Here, the perimeter of the circle lies on the surface of the sphere and the center of the planar circle is below the surface. These coordinates are converted to latitude and longitude for mapping fields on the surface of the earth.

  12. Comprehensive kinetic analysis of the plasma-wall transition layer in a strongly tilted magnetic field

    SciTech Connect (OSTI)

    Tskhakaya, D. D.; Kos, L.

    2014-10-15

    The magnetized plasma-wall transition (MPWT) layer at the presence of the obliquity of the magnetic field to the wall consists of three sub-layers: the Debye sheath (DS), the magnetic pre-sheath (MPS), and the collisional pre-sheath (CPS) with characteristic lengths ?{sub D} (electron Debye length), ?{sub i} (ion gyro-radius), and ? (the smallest relevant collision length), respectively. Tokamak plasmas are usually assumed to have the ordering ?{sub D}??{sub i}??, when the above-mentioned sub-layers can be distinctly distinguished. In the limits of ?{sub Dm}(?{sub D}/?{sub i})?0 and ?{sub mc}(?{sub i}/?)?0 (asymptotic three-scale (A3S) limits), these sub-layers are precisely defined. Using the smallness of the tilting angle of the magnetic field to the wall, the ion distribution functions are found for three sub-regions in the analytic form. The equations and characteristic length-scales governing the transition (intermediate) regions between the neighboring sub-layers (CPS MPS and MPS DS) are derived, allowing to avoid the singularities arising from the ?{sub Dm}?0 and ?{sub mc}?0 approximations. The MPS entrance and the related kinetic form of the BohmChodura condition are successfully defined for the first time. At the DS entrance, the Bohm condition maintains its usual form. The results encourage further study and understanding of physics of the MPWT layers in the modern plasma facilities.

  13. Segregation and Migration of the Oxygen Vacancies in the 3 (111) Tilt Grain Boundaries of Ceria

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

    Yuan, Fenglin; Liu, Bin; Zhang, Yanwen; Weber, William J.

    2016-03-01

    In nanocrystalline materials, defect-grain boundary (GB) interaction plays a key role in determining the structure stability, as well as size-dependent ionic, electronic, magnetic and chemical properties. In this study, we systematically investigated using density functional theory segregation and migration of oxygen vacancies at the Σ3 [110] / (111) grain boundary of ceria. Three oxygen layers near the GB are predicted to be segregation sites for oxygen vacancies. Moreover, the presence of oxygen vacancies stabilizes this tilt GB at a low Fermi level and/or oxygen poor conditions. An atomic strain model was proposed to rationalize layer dependency of the relaxation energymore » for +2 charged oxygen vacancy. The structural origin of large relaxation energies at layers 1 and 2 was determined to be free-volume space that induces ion relaxation towards the GB. Our results not only pave the way for improving the oxygen transport near GBs of ceria, but also provide important insights into engineering the GB structure for better ionic, magnetic and chemical properties of nanocrystalline ceria.« less

  14. Noncircular skyrmion and its anisotropic response in thin films of chiral magnets under a tilted magnetic field

    SciTech Connect (OSTI)

    Lin, Shi-Zeng; Saxena, Avadh

    2015-11-03

    Here we study the equilibrium and dynamical properties of skyrmions in thin films of chiral magnets with oblique magnetic field. The shape of an individual skyrmion is non-circular and the skyrmion density decreases with the tilt angle from the normal of films. As a result, the interaction between two skyrmions depends on the relative angle between them in addition to their separation. The triangular lattice of skyrmions under a perpendicular magnetic field is distorted into a centered rectangular lattice for a tilted magnetic field. For a low skyrmion density, skyrmions form a chain like structure. Lastly, the dynamical response of the non-circular skyrmions depends on the direction of external currents.

  15. Noncircular skyrmion and its anisotropic response in thin films of chiral magnets under a tilted magnetic field

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

    Lin, Shi-Zeng; Saxena, Avadh

    2015-11-03

    Here we study the equilibrium and dynamical properties of skyrmions in thin films of chiral magnets with oblique magnetic field. The shape of an individual skyrmion is non-circular and the skyrmion density decreases with the tilt angle from the normal of films. As a result, the interaction between two skyrmions depends on the relative angle between them in addition to their separation. The triangular lattice of skyrmions under a perpendicular magnetic field is distorted into a centered rectangular lattice for a tilted magnetic field. For a low skyrmion density, skyrmions form a chain like structure. Lastly, the dynamical response ofmore » the non-circular skyrmions depends on the direction of external currents.« less

  16. Micromagnetic study of spin transfer switching with a spin polarization tilted out of the free layer plane

    SciTech Connect (OSTI)

    Chaves-O'Flynn, Gabriel D. Wolf, Georg; Pinna, Daniele; Kent, Andrew D.

    2015-05-07

    We present the results of zero temperature macrospin and micromagnetic simulations of spin transfer switching of thin film nanomagnets in the shape of an ellipse with a spin-polarization tilted out of the layer plane. The perpendicular component of the spin-polarization is shown to increase the reversal speed, leading to a lower current for switching in a given time. However, for tilt angles larger than a critical angle, the layer magnetization starts to precess about an out-of-plane axis, which leads to a final magnetization state that is very sensitive to simulation conditions. As the ellipse lateral size increases, this out-of-plane precession is suppressed, due to the excitation of spatially non-uniform magnetization modes.

  17. ELECTRON IRRADIATION OF SOLIDS

    DOE Patents [OSTI]

    Damask, A.C.

    1959-11-01

    A method is presented for altering physical properties of certain solids, such as enhancing the usefulness of solids, in which atomic interchange occurs through a vacancy mechanism, electron irradiation, and temperature control. In a centain class of metals, alloys, and semiconductors, diffusion or displacement of atoms occurs through a vacancy mechanism, i.e., an atom can only move when there exists a vacant atomic or lattice site in an adjacent position. In the process of the invention highenergy electron irradiation produces additional vacancies in a solid over those normally occurring at a given temperature and allows diffusion of the component atoms of the solid to proceed at temperatures at which it would not occur under thermal means alone in any reasonable length of time. The invention offers a precise way to increase the number of vacancies and thereby, to a controlled degree, change the physical properties of some materials, such as resistivity or hardness.

  18. BIOLOGICAL IRRADIATION FACILITY

    DOE Patents [OSTI]

    McCorkle, W.H.; Cern, H.S.

    1962-04-24

    A facility for irradiating biological specimens with neutrons is described. It includes a reactor wherein the core is off center in a reflector. A high-exposure room is located outside the reactor on the side nearest the core while a low-exposure room is located on the opposite side. Means for converting thermal neutrons to fast neutrons are movably disposed between the reactor core and the high and low-exposure rooms. (AEC)

  19. 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.

    2012-11-26

    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

  20. Observed Regimes of Mid-Latitude.and Tropical Cirrus Microphysical Behavior

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

    Observed Regimes of Mid-Latitude and Tropical Cirrus Microphysical Behavior A. D. Del Genio and A. B. Wolf National Aeronautics Space Administration Goddard Institute for Space Studies New York, New York G. G. Mace University of Utah Salt Lake City, Utah L. M. Miloshevich National Center for Atmospheric Research Boulder, Colorado Introduction Little is known about the climatological microphysical properties of cirrus clouds. Thus, general circulation model (GCM) cirrus parameterizations often

  1. Cluster Analysis of Cloud Regimes and Characteristic Dynamics of Mid-Latitude Synoptic Systems

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

    Cluster Analysis of Cloud Regimes and Characteristic Dynamics of Mid-Latitude Synoptic Systems N. D. Gordon and J. R. Norris Scripps Institution of Oceanography University of California San Diego, La Jolla, California C. P. Weaver Center for Environmental Prediction Rutgers University New Brunswick, New Jersey S. A. Klein Geophysical Fluid Dynamics Laboratory Princeton University Princeton, New Jersey Introduction This study uses a clustering algorithm to group meteorological regimes by cloud

  2. Coherent radar estimates of average high-latitude ionospheric Joule heating

    SciTech Connect (OSTI)

    Kosch, M.J.; Nielsen, E.

    1995-07-01

    The Scandinavian Twin Auroral Radar Experiment (STARE) and Sweden and Britain Radar Experiment (SABRE) bistatic coherent radar systems have been employed to estimate the spatial and temporal variation of the ionospheric Joule heating in the combined geographic latitude range 63.8 deg - 72.6 deg (corrected geomagnetic latitude 61.5 deg - 69.3 deg) over Scandinavia. The 173 days of good observations with all four radars have been analyzed during the period 1982 to 1986 to estimate the average ionospheric electric field versus time and latitude. The AE dependent empirical model of ionospheric Pedersen conductivity of Spiro et al. (1982) has been used to calculate the Joule heating. The latitudinal and diurnal variation of Joule heating as well as the estimated mean hemispherical heating of 1.7 x 10(exp 11) W are in good agreement with earlier results. Average Joule heating was found to vary linearly with the AE, AU, and AL indices and as a second-order power law with Kp. The average Joule heating was also examined as a function of the direction and magnitude of the interplanetary magnetic field. It has been shown for the first time that the ionospheric electric field magnitude as well as the Joule heating increase with increasingly negative (southward) Bz.

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

    SciTech Connect (OSTI)

    Seager, Richard

    2014-12-08

    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.

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

    SciTech Connect (OSTI)

    Uberuaga, Blas P.

    2012-05-02

    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

  5. A FALSE POSITIVE FOR OCEAN GLINT ON EXOPLANETS: THE LATITUDE-ALBEDO EFFECT

    SciTech Connect (OSTI)

    Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Abbot, Dorian S. [Department of Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States); Voigt, Aiko [Max Planck Institute for Meteorology, Bundesstr. 53, D-20146, Hamburg (Germany)

    2012-06-10

    Identifying liquid water on the surface of planets is a high priority, as this traditionally defines habitability. One proposed signature of oceans is specular reflection ('glint'), which increases the apparent albedo of a planet at crescent phases. We post-process a global climate model of an Earth-like planet to simulate reflected light curves. Significantly, we obtain glint-like phase variations even though we do not include specular reflection in our model. This false positive is the product of two generic properties: (1) for modest obliquities, a planet's poles receive less orbit-averaged stellar flux than its equator, so the poles are more likely to be covered in highly reflective snow and ice; and (2) we show that reflected light from a modest-obliquity planet at crescent phases probes higher latitudes than at gibbous phases, therefore a planet's apparent albedo will naturally increase at crescent phase. We suggest that this 'latitude-albedo effect' will operate even for large obliquities: in that case the equator receives less orbit-averaged flux than the poles, and the equator is preferentially sampled at crescent phase. Using rotational and orbital color variations to map the surfaces of directly imaged planets and estimate their obliquity will therefore be a necessary pre-condition for properly interpreting their reflected phase variations. The latitude-albedo effect is a particularly convincing glint false positive for zero-obliquity planets, and such worlds are not amenable to latitudinal mapping. This effect severely limits the utility of specular reflection for detecting oceans on exoplanets.

  6. Sedimentation and reservoir distribution related to a tilted block system in the Sardinia Oligocene-Miocene rift (Italy)

    SciTech Connect (OSTI)

    Tremolieres, P.; Cherchi, A.; Eschard, R.; De Graciansky, P.C.; Montadert, L.

    1988-08-01

    In the western Mediterranean basin lies a rift system about 250 km long and 50 km wide and its infilling outcrop (central Sardinia). Seismic reflection surveys show its offshore extension. Block tilting started during the late Oligocene and lasted during Aquitanian-early Burdigalian time. Two main fault trends, with synthetic and antithetic throws, define the more-or-less collapsed blocks. This morphology guided the transit and trapping of sediments. The sedimentation started in a continental environment then, since the Chattian, in marine conditions. In the central part, the series can reach a thickness of 2,000 m. The basement composition and the volcanics products related to the main fault motion controlled the nature of the synrift deposits. According to their location in the rift context, the tilted blocks trap either continental deposits or marine siliciclastic or carbonate deposits. In the deeper part of the graben, sands were redeposited by gravity flows into the basinal marls. The younger prerift deposits are from Eocene to early Oligocene age and locally comprise thick coal layers. Postrift deposits, mainly marls, sealed the blocks and synrift sedimentary bodies. In middle and late Miocene time some faults were reactivated during compressional events. Then, a quaternary extensional phase created the Campidano graben, filled with about 1,000 m of sediments superimposed on the Oligocene-Miocene rift.

  7. Latitude survey investigation of galactic cosmic ray solar modulation during 1994-2007

    SciTech Connect (OSTI)

    Nuntiyakul, W.; Ruffolo, D.; Siz, A.; Evenson, P.; Bieber, J. W.; Clem, J.; Pyle, R.; Duldig, M. L.; Humble, J. E. E-mail: david.ruf@mahidol.ac.th E-mail: evenson@udel.edu E-mail: clem@bartol.udel.edu E-mail: John.Humble@utas.edu.au

    2014-11-01

    The Galactic cosmic ray spectrum exhibits subtle variations over the 22 yr solar magnetic cycle in addition to the more dramatic variations over the 11 yr sunspot cycle. Neutron monitors are large ground-based detectors that provide accurate measurements of variations in the cosmic ray flux at the top of the atmosphere above the detector. At any given location the magnetic field of the Earth excludes particles below a well-defined rigidity (momentum per unit charge) known as the cutoff rigidity, which can be accurately calculated using detailed models of the geomagnetic field. By carrying a neutron monitor to different locations, e.g., on a ship, the Earth itself serves as a magnet spectrometer. By repeating such latitude surveys with identical equipment, a sensitive measurement of changes in the spectrum can be made. In this work, we analyze data from the 1994 through 2007 series of latitude surveys conducted by the Bartol Research Institute, the University of Tasmania, and the Australian Antarctic Division. We confirm the curious 'crossover' in spectra measured near solar minima during epochs of opposite solar magnetic polarity, and show that it is directly related to a sudden change in the spectral behavior of solar modulation at the time of the polarity reversal, as revealed from contemporaneous variations in the survey data and a fixed station. We suggest that the spectral change and crossover result from the interaction of effects due to gradient/curvature drifts with a systematic change in the interplanetary diffusion coefficient caused by turbulent magnetic helicity.

  8. 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.

    2015-02-26

    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 phasemoreon 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

  9. Reconciliation of local and long-range tilt correlations in underdoped La2-xBaxCuO4(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.

    2015-02-26

    A long standing puzzle regarding the disparity of local and long range CuO₆ octahedral tilt correlations in the underdoped regime of La₂₋xBaxCuO₄ is addressed by utilizing complementary neutron powder diffraction and inelastic neutron scattering (INS) approaches. Long-range and static CuO₆ tilt order with orthogonally inequivalent Cu-O bonds in the CuO₂ 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. As a result, this study also exemplifies the importance of a systematic approach using complementary techniques when investigating systems exhibiting a large degree of complexity and subtle

  10. 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.

    2014-09-11

    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.

  11. Slag recycling of irradiated vanadium

    SciTech Connect (OSTI)

    Gorman, P.K.

    1995-04-05

    An experimental inductoslag apparatus to recycle irradiated vanadium was fabricated and tested. An experimental electroslag apparatus was also used to test possible slags. The testing was carried out with slag materials that were fabricated along with impurity bearing vanadium samples. Results obtained include computer simulated thermochemical calculations and experimentally determined removal efficiencies of the transmutation impurities. Analyses of the samples before and after testing were carried out to determine if the slag did indeed remove the transmutation impurities from the irradiated vanadium.

  12. Unit-cell thick BaTiO{sub 3} blocks octahedral tilt propagation across oxide heterointerface

    SciTech Connect (OSTI)

    Kan, Daisuke Aso, Ryotaro; Kurata, Hiroki; Shimakawa, Yuichi

    2014-05-14

    We fabricated SrRuO{sub 3}/BaTiO{sub 3}/GdScO{sub 3} heterostructures in which the BaTiO{sub 3} layer is one unit cell thick by pulsed laser deposition and elucidated how the BaTiO{sub 3} layer influences structural and magneto-transport properties of the SrRuO{sub 3} layer through octahedral connections across the heterointerface. Our X-ray-diffraction-based structural characterizations show that while an epitaxial SrRuO{sub 3} layer grown directly on a GdScO{sub 3} substrate is in the monoclinic phase with RuO{sub 6} octahedral tilts, a one-unit-cell-thick BaTiO{sub 3} layer inserted between SrRuO{sub 3} and GdScO{sub 3} stabilizes the tetragonal SrRuO{sub 3} layer with largely reduced RuO{sub 6} tilts. Our high-angle annular dark-field and annular bright-field scanning transmission electron microscopy observations provide an atomic-level view of the octahedral connections across the heterostructure and reveal that the BaTiO{sub 3} layer only one unit cell thick is thick enough to stabilize the RuO{sub 6}-TiO{sub 6} octahedral connections with negligible in-plane oxygen atomic displacements. This results in no octahedral tilts propagating into the SrRuO{sub 3} layer and leads to the formation of a tetragonal SrRuO{sub 3} layer. The magneto-transport property characterizations also reveal a strong impact of the octahedral connections modified by the inserted BaTiO{sub 3} layer on the spin-orbit interaction of the SrRuO{sub 3} layer. The SrRuO{sub 3} layer on BaTiO{sub 3}/ GdScO{sub 3} has in-plane magnetic anisotropy. This is in contrast to the magnetic anisotropy of the monoclinic SrRuO{sub 3} films on the GdScO{sub 3} substrate, in which the easy axis is ?45 to the film surface normal. Our results demonstrate that the one-unit-cell-thick layer of BaTiO{sub 3} can control and manipulate the interfacial octahedral connection closely linked to the structure-property relationship of heterostructures.

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

    SciTech Connect (OSTI)

    Howe, R.; Christensen-Dalsgaard, J.; Hill, F.; Komm, R.; Larson, T. P.; Schou, J.; Rempel, M.; Thompson, M. J.

    2013-04-10

    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.

  14. Quaternary sedimentation and diagenesis in a high-latitude reef, Houtman Abrolhos Islands, Western Australia

    SciTech Connect (OSTI)

    Rosen, M.R.; Collins, L.B. (Curtin Univ. of Technology, Perth, Western Australia (Australia)); Wyrwoll, K.H.; Hatcher, B.G. (Univ. of Western Australia, Perth (Australia))

    1990-05-01

    The Houtman Abrolhos reefs are located 80 km off the west coast of Australia between latitudes 28 and 29{degree} south. The islands are situated on three Pleistocene carbonate reef platforms which rise above the surrounding shelf. The modern coral reefs are close to the geographic limit for coral growth in the southern hemisphere and survive due to the presence of the Leeuwin current (a poleward-flowing warm stream). Two major shallow-water benthic communities coexist in the Abrolhos: a macroalgal-dominated community on the windward platform margins and a coral-dominated community on the leeward margins. These communities overlap-particularly in the platform lagoons, where competition between macroalgae and corals is intense. This interaction has been suggested as a major factor controlling the growth of cord reefs at high latitudes. The Holocene carbonate sediments lack nonskeletal components and are dominated by coral and coralline algal fragments with subordinate molluskan and echinoderm debris. The accumulations can be grouped into the following major facies: (1) coral framestone and coralline algal/serpulid boundstone, (2) submarine sand sheets, (3) subaerial coral storm ridges, (4-) peritidal to subtidal shingle and rubble veneers composed of dominantly coral debris, and (5) eolian dunes and beach sand. The Holocene sediment is a thin (< 2 m) veneer on the Pleistocene reef platform, which is emergent as small islands. The Pleistocene platform is composed of reef facies that can be directly related to the Holocene sediments. The platform is composed of framestone and boundstone facies (corals and coralline algal/serpulid facies), rudstones (submarine coral rubble facies), planar-bedded skeletal grainstones dipping 12-13{degree} (submarine sand sheet and peritidal shingle facies), and large 15-m-high eolianite dunes (eolian dune facies).

  15. Tritium Related Material Research -Irradiation Effect on Isotropic...

    Office of Environmental Management (EM)

    Related Material Research -Irradiation Effect on Isotropic Graphite Utilizing Heavy Ion-Irradiation- Tritium Related Material Research -Irradiation Effect on Isotropic Graphite...

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

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

    (HFIR). Irradiation of the capsules was conducted for post-irradiation examination (PIE) metallography. PDF icon Neutron Irradiation of Hydrided Cladding Material in HFIR...

  17. Statistical criteria for characterizing irradiance time series.

    SciTech Connect (OSTI)

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

    2010-10-01

    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.

  18. Ultrasonic Transducer Irradiation Test Results

    SciTech Connect (OSTI)

    Daw, Joshua; Palmer, Joe; Ramuhalli, Pradeep; Keller, Paul; Montgomery, Robert; Chien, Hual-Te; Kohse, Gordon; Tittmann, Bernhard; Reinhardt, Brian; Rempe, Joy

    2015-02-01

    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 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 ongoing 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 identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. For this reason, the Pennsylvania State University (PSU) was awarded an ATR NSUF project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2. The goal of this research is to characterize and demonstrate magnetostrictive and piezoelectric transducer operation during irradiation, enabling the development of novel radiation-tolerant ultrasonic sensors for use in Material Testing Reactors (MTRs). As such, this test is an instrumented lead test and real-time transducer performance data is 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. To date, one piezoelectric

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

    SciTech Connect (OSTI)

    Abdo, A.A.; Ackermann, M.; Ajello, M.; Anderson, B.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Baughman, B.M.; Bechtol, K.; Bellazzini, R.; Berenji, B.; Blandford, R.D.; Bloom, E.D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brez, A.; Brigida, M.; /more authors..

    2012-04-11

    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.

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

    SciTech Connect (OSTI)

    Mcguire, David; Kicklighter, David W.; Gurney, Kevin R; Burnside, Todd; Melillo, Jerry

    2011-01-01

    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.

  1. Study of mid-latitude 5577A CI dayglow emissions. Doctoral thesis

    SciTech Connect (OSTI)

    Hume, E.E.

    1992-01-01

    Summary of thesis: The green line (5577angstroms) is a bright, persistent component of the visible airglow. It is produced by an electric quadruple transition from the metastable second excited state (1So) to the first excited state (1D2) of atomic oxygen. These two excited states all lie in the same electron shell of the atom and have the same electron configuration as the ground state of 1s22s22p4, which is the 3P2,1,0. This emission is present in both the daytime and night airglow and in the aurora, and despite a long history of study it is still not fully understood. The emission in the dayglow and the nightglow is relatively homogeneous spatially and global in coverage. In the aurora, the emission is much brighter than the airglow, high structured and very localized being restricted to higher latitudes. The structure of the 5577angstroms emission with altitude and the chemistry responsible for the production of the emission are complex. The vertical structure for the emission has two distinct layers in the airglow each with its own set of production and loss mechanisms. the chemistry for either of these layers is not completely known. The auroral emission is not understood either since it overlaps the upper and lower layer altitudes and it tends to contain some parts of the chemistry of both layers as sources and losses.

  2. Generation of short gamma-ray pulses on electron bunches formed in intense interfering laser beams with tilted fronts

    SciTech Connect (OSTI)

    Korobkin, V V; Romanovskiy, M Yu; Trofimov, V A; Shiryaev, O B

    2014-05-30

    It is shown that in the interference of multiple laser pulses with a relativistic intensity, phase and amplitude fronts of which are tilted at an angle with respect to their wave vector, effective traps of charged particles, which are moving at the velocity of light, are formed. Such traps are capable of capturing and accelerating the electrons produced in the ionisation of low-density gas by means of laser radiation. The accelerated electrons in the traps form a bunch, whose dimensions in all directions are much smaller than the laser radiation wavelength. Calculations show that the energy of accelerated electrons may amount to several hundred GeV at experimentally accessible relativistic laser intensities. As a result of the inverse Compton scattering, gamma-quanta with a high energy and narrow radiation pattern are emitted when these electrons interact with a laser pulse propagating from the opposite direction. The duration of emitted gamma-ray pulses constitutes a few attoseconds. The simulation is performed by solving the relativistic equation of motion for an electron with a relevant Lorentz force. (interaction of radiation with matter)

  3. Magnetic rotation (MR) band crossing in N=78 odd-Z nuclei: Tilted axis cranking (TAC) calculations to explore the role of nucleons

    SciTech Connect (OSTI)

    Kumar, Suresh

    2014-08-14

    Magnetic Rotation (MR) band crossing is studied systematically in N=78 isotones (La, Pr, Pm and Eu) using Tilted Axis Cranking (TAC) model. The observables such as I(h) vs h?, excitation energy E(MeV) vs spin I(h), and the B(M1)/B(E2) vs I(h) were considered to pinpoint MR crossing in these nuclei. The results of tilted axis cranking were compared with these experimental observables. The B(M1) and B(E2) values were also reported and used to understand the crossing behaviour of these MR bands. The systematic evolution of this phenomenon in N=78 odd-Z istotones leads to understand the role of nucleons in MR band crossing.

  4. 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.

    2014-08-27

    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.

  5. Reconciliation of local and long-range tilt correlations in underdoped La 2 x Ba x CuO 4 ( 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.

    2015-02-26

    A long-standing puzzle regarding the disparity of local and long-range CuO? octahedral tilt correlations in the underdoped regime of La2xBaxCuO? is addressed by utilizing complementary neutron powder diffraction and inelastic neutron scattering (INS) approaches. This system is of interest because of the strong depression of the bulk superconducting transition at x=1/8 in association with charge and spin stripe order. The latter unidirectional order is tied to Cu-O bond-length anisotropy present in the so-called low-temperature tetragonal (LTT) phase. On warming, the lattice exhibits two sequential structural transitions, involving changes in the CuO? tilt pattern, first to the low-temperature orthorhombic (LTO) andmorethen the high-temperature tetragonal (HTT) phase. Despite the changes in static order, inspection of the instantaneous local atomic structure suggests that the LTT-type tilts persist through the transitions. Analysis of the INS spectra for the x=1/8 composition reveals the dynamic nature of the LTT-like tilt fluctuations within the LTO and HTT phases. Within the low-temperature phase, the Cu-O bond-length splitting inferred from lattice symmetry and fitted atomic position parameters reaches a maximum of 0.3% at x=1/8, suggesting that electron-phonon coupling may contribute to optimizing the structure to stabilize stripe order. This splitting is much too small to be resolved in the pair distribution function, and in fact we do not resolve any enhancement of the instantaneous bond-length distribution in association with stripe order. This study exemplifies the importance of a systematic approach using complementary techniques when investigating systems exhibiting a large degree of complexity and subtle structural responses.less

  6. Solar UV radiation exposure of seamen - Measurements, calibration and model calculations of erythemal irradiance along ship routes

    SciTech Connect (OSTI)

    Feister, Uwe; Meyer, Gabriele; Kirst, Ulrich

    2013-05-10

    Seamen working on vessels that go along tropical and subtropical routes are at risk to receive high doses of solar erythemal radiation. Due to small solar zenith angles and low ozone values, UV index and erythemal dose are much higher than at mid-and high latitudes. UV index values at tropical and subtropical Oceans can exceed UVI = 20, which is more than double of typical mid-latitude UV index values. Daily erythemal dose can exceed the 30-fold of typical midlatitude winter values. Measurements of erythemal exposure of different body parts on seamen have been performed along 4 routes of merchant vessels. The data base has been extended by two years of continuous solar irradiance measurements taken on the mast top of RV METEOR. Radiative transfer model calculations for clear sky along the ship routes have been performed that use satellite-based input for ozone and aerosols to provide maximum erythemal irradiance and dose. The whole data base is intended to be used to derive individual erythemal exposure of seamen during work-time.

  7. 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

    2012-09-01

    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.

  8. Generation of kinetic Alfven waves in the high-latitude near-Earth magnetotail: A global hybrid simulation

    SciTech Connect (OSTI)

    Guo, Zhifang; Hong, Minghua; Du, Aimin; Lin, Yu; Wang, Xueyi; Wu, Mingyu; Lu, Quanming

    2015-02-15

    In this paper, effects of a fast flow in the tail plasma sheet on the generation of kinetic Alfven waves (KAWs) in the high-latitude of the near-Earth magnetotail are investigated by performing a two-dimensional (2-D) global-scale hybrid simulation, where the plasma flow is initialized by the EB drift near the equatorial plane due to the existence of the dawn-dusk convection electric field. It is found that firstly, the plasma sheet becomes thinned and the dipolarization of magnetic field appears around (x,z)=(?10.5R{sub E},0.3R{sub E}), where R{sub E} is the radius of the Earth. Then, shear Alfven waves are excited in the plasma sheet, and the strong earthward flow is braked by the dipole-like magnetic field. These waves propagate along the magnetic field lines toward the polar regions later. Subsequently, KAWs with k{sub ?}?k{sub ?} are generated in the high-latitude magnetotail due to the existence of the non-uniformity of the magnetic field and density in the polar regions. The ratio of the electric field to the magnetic field in these waves is found to obey the relation (?E{sub z})/(?B{sub y}?)??/k{sub ?} of KAWs. Our simulation provides a mechanism for the generation of the observed low-frequency shear Alfven waves in the plasma sheet and kinetic Alfven waves in the high-latitude near-Earth magnetotail, whose source is suggested to be the flow braking in the low-latitude plasma sheet.

  9. Center for Materials at Irradiation and Mechanical Extremes:...

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

    This movie shows our molecular dynamics simulation of a collision cascade near an asymmetric 11 tilt grain boundary in copper over a time of 380 ps. The grain boundary is at the...

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

    SciTech Connect (OSTI)

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

    2013-04-10

    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.

  11. Tilting at windmills

    SciTech Connect (OSTI)

    Gipe, P.

    1995-05-01

    In the spring of 1994 an angry mob confronted a group touring proposed sites for a new wind power plant near Mojave, Calif. The armed vigilantes were responding to rumors that the U.S. Bureau of Land Management was planning to build a wind farm near their remote homesteads. Though there was no truth to the rumors and the incident was settled peacefully, the event illustrates the sometimes highly charged atmosphere around proposals for new wind plants, or for power plants of any kind, in the United States. Analysis of surveys by the British Broadcasting Corp (BBC) and the Department of Trade & Industry in the UNited Kingdom; MRL Research Group in New Zealand; and th Center for Design Research in California gives potential developers and investors useful insights into publi attitudes toward wind power. In genral, the surveys on both sides of the Atlantic reveal that those who favor renewable energy are more likely to find wind`s effect on the community acceptable, and those who are neutral will accept wind turbines in the landscape if they know they are beneficial.

  12. Tilting at windmills

    SciTech Connect (OSTI)

    Garvin, C.C. Jr.

    1981-01-01

    Mr. Garvin feels that mutual understanding between environmentalists and oil companies will solve energy problems faster than the confrontational approach. Exxon's hope that nuclear energy, coal, and synthetic fuels can bridge the transition to clean, renewable energy sources is in conflict with those of the Environmental Defense Fund. Even with a slower future economic growth and improved efficiency, Exxon anticipates a greater demand for energy and sees its responsibility to produce energy along with a reasonable return to its shareholders. Most of the conservation can be achieved with realistic policies that price energy at its replacement cost and allow economic growth to continue. The major uncertainty in meeting future energy demand is the depletion of conventionally-produced oil and the need for another source to pick up the difference. Although health and safety concerns are the major uncertainties for nuclear and coal, the alternatives to not following this route may present even greater risks if renewable sources are inadequate in this century. Economic criteria should be applied to energy development, but both sides need to be aware of the consequences should they be wrong. (DCK)

  13. Tilting toward windmills

    SciTech Connect (OSTI)

    McGowan, J.G. . Renewable Energy Research Lab.)

    1993-07-01

    Emerging from the shadow of an energy crisis in the 1970s, a wind-power industry flourished briefly in the US. Part of an ambitious US government program to support research and development on renewable energy sources, the Department of Energy and the National Aeronautic and Space Agency sponsored the construction of a wide variety of large wind turbines-most accompanied by exaggerated claims by the promoters. But by the 1980s, US interest in wind power almost disappeared due to a drop in world oil prices, the Reagan administrations curtailment of funding, and the disappointing results of the initial wind turbines. The problems with the initial wind turbines was overly optimistic economic projections, siting snags, difficulties connecting wind-generated electricity to utility power grids. Today, however the wind farms in California are a highly productive, inexpensive source of energy. The author presents arguments dispelling the following four widely-believed myths about wind energy: (1) Wind power is not a significant energy source; (2) Wind-generated electricity is expensive and unreliable; (3) New and improved machine designs are needed to make wind power feasible; and (4) The technology is impractical for use by utilities because of problems connecting wind machines to the electricity grid, and because wind itself is intermittent. A study at Battelle Pacific Northwest Lab estimates that turbine technology could supply 20% of the country's electrical needs. Investor-owned wind-power plants in California generate electricity at a rate ranging from 4.7 to 7.2 cents per kilowatt-hour. The reality is that wind-produced electricity is now less expensive that electricity produced by conventional fossil- or nuclear-powered generating plants in many parts of the world. And unlike some of the proposed renewable electric-power sources like photovoltaics, wind power's future is not dependent on further breakthroughs in engineering or materials technology.

  14. Tilting at windmills

    SciTech Connect (OSTI)

    Selde, V.

    1982-04-01

    The three MOD-2, 300 ft. blade windmills, situated in the Goodnoe Hills in Washington state are described. Built by Boeing Engineering and Construction and financed by the DOE ($35 million) and the Bonneville Power Administration ($2 million), the wind turbines are rated at 2.5 megawatts of capacity per turbine. The need for the large size of the blades (world's largest) is explained as well as the factors influencing the site selection. It is pointed out that efficiency increases as the square of the rotor diameter and a wind velocity of at least 14 m.p.h. is required. The various factors and people involved in the financial aspects of commercialization of large windmills are discussed. Current cost of power generated is about $0.10/kWh. This can be reduced to $0.04-0.05/kwh by developing a facility with 100 windmills. Control of the facility by computers, safety features, rotor and tower design and the test program are described as well as environmental effects. (MJJ)

  15. Irradiation preservation of seafood: Literature review

    SciTech Connect (OSTI)

    Molton, P.M.

    1987-10-01

    The application of gamma-irradiation for extending the shelf life of seafood has been of interest for many years. This report reviews a number of studies on seafood irradiation conducted over the past several years. Topics covered include seafood irradiation techniques and dosages, species applicability and differences, the effects of packaging on seafood preservation, and changes in organoleptic acceptability as a result of irradiation. Particular attention is given to radiation effects (likely and unlikely) of concern to the public. These include the potential for generation of toxic chemical products, botulinum toxin production, and other health concerns. No scientifically defensible evidence of any kind was found for any harmful effect of irradiation of seafoods at the doses being considered (less than 300 krad), and all indications are that irradiation is an acceptable and needed additional tool for seafood preservation. 49 refs., 14 figs., 14 tabs.

  16. (Irradiation embrittlement of reactor pressure vessels)

    SciTech Connect (OSTI)

    Corwin, W.R.

    1990-09-24

    The traveler served as a member of the two-man US Nuclear Regulatory Commission sponsored team who visited the Prometey Complex in Leningrad to assess the potential for expanded cooperative research concerning integrity of the primary pressure boundary in commercial light-water reactors. The emphasis was on irradiation embrittlement, structural analysis, and fracture mechanics research for reactor pressure vessels. At the irradiation seminar in Cologne, presentations were made by German, French, Finnish, Russian, and US delegations concerning many aspects of irradiation of pressure vessel steels. The traveler made presentations on mechanisms of irradiation embrittlement and on important aspects of the Heavy-Section Steel Irradiation Program results of irradiated fracture mechanics tests.

  17. 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

    2013-12-01

    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.

  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

    2014-07-30

    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. A New Solar Irradiance Reference Spectrum

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

    A New Solar Irradiance Reference Spectrum Pilewskie, Peter University of Colorado ... We describe the development of a new solar reference spectrum for radiation and climate ...

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

    Office of Environmental Management (EM)

    Fuels Examination Laboratory - April 2015 April 2015 Review of the Safety-Significant Ventilation Systems at the Irradiated Fuels Examination Laboratory Operated by UT-Battelle...

  1. Comparison of irradiation creep and swelling of an austenitic alloy irradiated in FFTF and PFR

    SciTech Connect (OSTI)

    Garner, F.A.; Toloczko, M.B.; Munro, B.; Adaway, S.; Standring, J.

    1999-10-01

    comparative irradiation of identically constructed creep tubes in the Fast Flux Test Facility (FFTF) and the Prototypic Fast Reactor (PFR) shows that differences in irradiation conditions arising from both reactor operation and the design of the irradiation vehicle can have a significant impact on the void swelling and irradiation creep of austenitic stainless steels. In spite of these differences, the derived creep coefficients fall within the range of previously observed values for 316 SS.

  2. Effect of electron-density gradients on propagation of radio waves in the mid-latitude trough. Master's thesis

    SciTech Connect (OSTI)

    Citrone, P.J.

    1991-01-01

    Partial contents of this thesis include: (1) Radio-wave propagation and the mid-latitude trough; (2) Ionospheric measurements; (3) Modification of time-dependent ionospheric model output with latitudinal electron-density profiles from digisonde trough depictions; (4) Ray-tracing simulations to examine ground range; and (5) Effects of three-dimensional gradients in electron density on radio-wave propagation in the trough region. Data is tabulated for geophysical conditions, solar activity level, geomagnetic activity level, conditions for vertical ray refraction to surface, and ray-tracing fixed-input conditions.

  3. Schedule and status of irradiation experiments

    SciTech Connect (OSTI)

    Rowcliffe, A.F.; Grossbeck, M.L.; Robertson, J.P.

    1998-09-01

    The current status of reactor irradiation experiments is presented in tables summarizing the experimental objectives, conditions, and schedule. Currently, the program has one irradiation experiment in reactor and five experiments in the design or construction stages. Postirradiation examination and testing is in progress on ten experiments.

  4. AGR-1 Post Irradiation Examination Final Report

    SciTech Connect (OSTI)

    Demkowicz, Paul Andrew

    2015-08-01

    The post-irradiation examination (PIE) of the Advanced Gas Reactor (AGR)-1 experiment was a multi-year, collaborative effort between Idaho National Laboratory (INL) and Oak Ridge National Laboratory (ORNL) to study the performance of UCO (uranium carbide, uranium oxide) tristructural isotropic (TRISO) coated particle fuel fabricated in the U.S. and irradiated at the Advanced Test Reactor at INL to a peak burnup of 19.6% fissions per initial metal atom. This work involved a broad array of experiments and analyses to evaluate the level of fission product retention by the fuel particles and compacts (both during irradiation and during post-irradiation heating tests to simulate reactor accident conditions), investigate the kernel and coating layer morphology evolution and the causes of coating failure, and explore the migration of fission products through the coating layers. The results have generally confirmed the excellent performance of the AGR-1 fuel, first indicated during the irradiation by the observation of zero TRISO coated particle failures out of 298,000 particles in the experiment. Overall release of fission products was determined by PIE to have been relatively low during the irradiation. A significant finding was the extremely low levels of cesium released through intact coatings. This was true both during the irradiation and during post-irradiation heating tests to temperatures as high as 1800°C. Post-irradiation safety test fuel performance was generally excellent. Silver release from the particles and compacts during irradiation was often very high. Extensive microanalysis of fuel particles was performed after irradiation and after high-temperature safety testing. The results of particle microanalysis indicate that the UCO fuel is effective at controlling the oxygen partial pressure within the particle and limiting kernel migration. Post-irradiation examination has provided the final body of data that speaks to the quality of the AGR-1 fuel, building

  5. RERTR-7 Irradiation Summary Report

    SciTech Connect (OSTI)

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

    2011-12-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-7A, was designed to test several modified fuel designs to target fission densities representative of a peak low enriched uranium (LEU) burnup in excess of 90% U-235 at peak experiment power sufficient to generate a peak surface heat flux of approximately 300 W/cm2. The RERTR-7B experiment was designed as a high power test of 'second generation' dispersion fuels at peak experiment power sufficient to generate a surface heat flux on the order of 230 W/cm2.1 The following report summarizes the life of the RERTR-7A and RERTR-7B experiments through end of irradiation, including as-run neutronic analyses, thermal analyses and hydraulic testing results.

  6. RERTR-10 Irradiation Summary Report

    SciTech Connect (OSTI)

    D. M. Perez

    2011-05-01

    The Reduced Enrichment for Research and Test Reactor (RERTR) experiment RERTR-10 was designed to further test the effectiveness of modified fuel/clad interfaces in monolithic fuel plates. The experiment was conducted in two campaigns: RERTR-10A and RERTR-10B. The fuel plates tested in RERTR-10A were all fabricated by Hot Isostatic Pressing (HIP) and were designed to evaluate the effect of various Si levels in the interlayer and the thickness of the Zr interlayer (0.001”) using 0.010” and 0.020” nominal foil thicknesses. The fuel plates in RERTR-10B were fabricated by Friction Bonding (FB) with two different thickness Si layers and Nb and Zr diffusion barriers.1 The following report summarizes the life of the RERTR-10A/B experiment through end of irradiation, including as-run neutronic analysis results, thermal analysis results and hydraulic testing results.

  7. AFIP-3 Irradiation Summary Report

    SciTech Connect (OSTI)

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

    2011-05-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-3 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-3 experiment was fabricated by hot isostatic pressing (HIP) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-3 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  8. AFIP-3 Irradiation Summary Report

    SciTech Connect (OSTI)

    Danielle M Perez

    2011-04-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-3 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-3 experiment was fabricated by hot isostatic pressing (HIP) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-3 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  9. AFIP-3 Irradiation Summary Report

    SciTech Connect (OSTI)

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

    2012-03-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-3 was designed to evaluate the performance of monolithic fuels at a prototypic scale of 2.25 inches x 21.5 inches x 0.050 inches (5.75 cm x 54.6 cm x 0.13cm). The AFIP-3 experiment was fabricated by hot isostatic pressing (HIP) and consists of two plates, one with a zirconium (Zr) diffusion barrier and one with a silicon (Si) enhanced fuel/clad interface1,2. The following report summarizes the life of the AFIP-3 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  10. ARM: Baseline Solar Radiation Network (BSRN): solar irradiances...

    Office of Scientific and Technical Information (OSTI)

    Baseline Solar Radiation Network (BSRN): solar irradiances Title: ARM: Baseline Solar Radiation Network (BSRN): solar irradiances Baseline Solar Radiation Network (BSRN): solar ...

  11. PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: PLUTONIUM-238 RECOVERY FROM IRRADIATED ... and purifying 238Pu and unconverted 237Np post irradiation is by anion exchange (IX). ...

  12. Design of a Compact Fatigue Tester for Testing Irradiated Materials...

    Office of Scientific and Technical Information (OSTI)

    a hot cell for characterization of irradiated materials is beneficial to help determine relative fatigue performance differences between new and irradiated material. Hot cell use ...

  13. ARM: Multi-Filter Radiometer (MFR): upwelling irradiance at 3...

    Office of Scientific and Technical Information (OSTI)

    Multi-Filter Radiometer (MFR): upwelling irradiance at 3-meter height Title: ARM: Multi-Filter Radiometer (MFR): upwelling irradiance at 3-meter height Multi-Filter Radiometer ...

  14. Spatial correlation of energy deposition events in irradiated...

    Office of Scientific and Technical Information (OSTI)

    events in irradiated liquid water Citation Details In-Document Search Title: Spatial correlation of energy deposition events in irradiated liquid water You are accessing a ...

  15. Spatial correlation of energy deposition events in irradiated...

    Office of Scientific and Technical Information (OSTI)

    events in irradiated liquid water Citation Details In-Document Search Title: Spatial correlation of energy deposition events in irradiated liquid water Monte Carlo electron ...

  16. Production of high Resoulution Irradiance Data for Central America...

    Open Energy Info (EERE)

    irradiance (GHI) and direct irradiance (DNI) data sets for the countries of Cuba, El Salvador, Guatemala, Honduras and Nicaragua. Much of our initial effort focused on building up...

  17. Working with SRNL - Our Facilities- Gamma Irradiation Facility

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

    for irradiating solid and liquid samples, allowing a wide range of tests to determine the effects of radiation on materials. Typically, the Gamma Irradiation Facility is used to...

  18. Post Irradiation Examination of Stainless Steel Cladding from...

    Office of Environmental Management (EM)

    Post Irradiation Examination of Stainless Steel Cladding from In-Reactor Permeation Experiment Post Irradiation Examination of Stainless Steel Cladding from In-Reactor Permeation ...

  19. Radiochemistry Results from the IER-163 COMET Irradiation (Technical...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Radiochemistry Results from the IER-163 COMET Irradiation Citation Details In-Document Search Title: Radiochemistry Results from the IER-163 COMET Irradiation The ...

  20. Methods for Post Irradiation Examination of Tritium Producing...

    Office of Environmental Management (EM)

    Methods for Post Irradiation Examination of Tritium Producing Burnable Absorber Rods Methods for Post Irradiation Examination of Tritium Producing Burnable Absorber Rods...

  1. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    Irradiation Effects on Human Cortical Bone Fracture Behavior Irradiation Effects on Human Cortical Bone Fracture Behavior Print Wednesday, 28 July 2010 00:00 Human bone is strong ...

  2. Options for improving the load matching capability of distributed photovoltaics: Methodology and application to high-latitude data

    SciTech Connect (OSTI)

    Widen, Joakim; Waeckelgaard, Ewa; Lund, Peter D.

    2009-11-15

    At high latitudes, domestic electricity demand and insolation are negatively correlated on both an annual and a diurnal basis. With increasing integration of distributed photovoltaics (PV) in low-voltage distribution grids of residential areas, limits to the penetration level are set by voltage rise due to unmatched production and load. In this paper a methodology for determining the impacts of three options for increased load matching is presented and applied to high-latitude data. The studied options are PV array orientation, demand side management (DSM) and electricity storage. Detailed models for domestic electricity demand and PV output are used. An optimisation approach is applied to find an optimal distribution of PV systems on different array orientations and a best-case evaluation of DSM and a storage model are implemented. At high penetration levels, storage is the most efficient option for maximising the solar fraction, but at lower overproduction levels, the impact of DSM is equal or slightly better. An east-west orientation of PV arrays is suggested for high penetration levels, but the effect of the optimised orientation is small. Without an optimised storage operation, the overproduced power is more efficiently reduced by DSM than storage, although this is highly dependent on the applied DSM algorithm. Further research should be focused on the DSM potential and optimal operation of storage. (author)

  3. A novel facility for 3D micro-irradiation of living cells in a controlled environment by MeV ions

    SciTech Connect (OSTI)

    Mckel, V. Meissl, W.; Ikeda, T.; Meissl, E.; Kobayashi, T.; Kojima, T. M.; Ogiwara, K.; Yamazaki, Y.; Clever, M.; Imamoto, N.

    2014-01-15

    We present a novel facility for micro-irradiation of living targets with ions from a 1.7 MV tandem accelerator. We show results using 1 MeV protons and 2 MeV He{sup 2+}. In contrast to common micro-irradiation facilities, which use electromagnetic or electrostatic focusing and specially designed vacuum windows, we employ a tapered glass capillary with a thin end window, made from polystyrene with a thickness of 12 ?m, for ion focusing and extraction. The capillary is connected to a beamline tilted vertically by 45, which allows for easy immersion of the extracted ions into liquid environment within a standard cell culture dish. An inverted microscope is used for simultaneously observing the samples as well as the capillary tip, while a stage-top incubator provides an appropriate environment for the samples. Furthermore, our setup allows to target volumes in cells within a ?m{sup 3} resolution, while monitoring the target in real time during and after irradiation.

  4. Infrared spectroscopy study of irradiated PVDF

    SciTech Connect (OSTI)

    Chappa, Veronica; Grosso, Mariela del; Garcia Bermudez, Gerardo; Behar, Moni

    2007-10-26

    The effects induced by 1 MeV/amu ion irradiations were compared to those induced by 4-12 MeV/amu irradiations. Structural analysis with infrared spectroscopy (FTIR) was carried out on PVDF irradiated using C and He beams with different fluences. From these spectra it was observed, as a function of fluence, an overall destruction of the polymer, amorphization of the crystalline regions and the creation of in-chain unsaturations. The track dimensions were determined using a previously developed Monte Carlo simulation code and these results were compared to a semiempirical model.

  5. ARM - Measurement - Shortwave broadband diffuse downwelling irradiance

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

    diffuse downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband diffuse downwelling irradiance All of the solar radiation, across the wavelength range of 0.4 and 4 {mu}m, coming directly from the sky except for solar radiation coming directly from the sun and the circumsolar irradiance within approximately three degrees of the sun. Categories Radiometric Instruments

  6. Measuring Degradation Rates Without Irradiance Data

    SciTech Connect (OSTI)

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

    2011-02-01

    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.

  7. Gamma-ray irradiated polymer optical waveguides

    SciTech Connect (OSTI)

    Lai, C.-C.; Wei, T.-Y.; Chang, C.-Y.; Wang, W.-S.; Wei, Y.-Y.

    2008-01-14

    Optical waveguides fabricated by gamma-ray irradiation on polymer through a gold mask are presented. The gamma-ray induced index change is found almost linearly dependent on the dose of the irradiation. And the measured propagation losses are low enough for practical application. Due to the high penetrability of gamma ray, uniform refractive index change in depth can be easily achieved. Moreover, due to large-area printing, the uniformity of waveguide made by gamma-ray irradiation is much better than that by e-beam direct writing.

  8. Reconciliation of local and long-range tilt correlations in underdoped La2-xBaxCuO4(0 ? x ? 0.155)

    SciTech Connect (OSTI)

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

    2015-02-26

    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. As a result, this study also exemplifies the importance of a systematic approach using complementary techniques when investigating systems exhibiting a large degree of complexity and subtle

  9. Reconciliation of local and long-range tilt correlations in underdoped La2-xBaxCuO4(0 ≤ x ≤ 0.155)

    SciTech Connect (OSTI)

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

    2015-02-26

    A long standing puzzle regarding the disparity of local and long range CuO₆ octahedral tilt correlations in the underdoped regime of La₂₋xBaxCuO₄ is addressed by utilizing complementary neutron powder diffraction and inelastic neutron scattering (INS) approaches. Long-range and static CuO₆ tilt order with orthogonally inequivalent Cu-O bonds in the CuO₂ 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. As a result, this study also exemplifies the importance of a systematic approach using complementary techniques when investigating systems exhibiting a large degree of complexity

  10. Sandia National Laboratories: Research: Facilities: Gamma Irradiation...

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

    second. The neutron irradiation system consisting of the AmBe source and a large polyethylene chamber provides neutron dose rates from 10-6 radsecond to 10-5 radsecond....

  11. Gamma irradiation effects in W films

    SciTech Connect (OSTI)

    Claro, Luiz H.; Santos, Ingrid A.; Silva, Cassia F.

    2013-05-06

    Using the van Der Pauw methodology, the surface resistivity of irradiated tungsten films deposited on Silicon substrate was measured. The films were exposed to {gamma} radiation using a isotopic {sup 60}Co source in three irradiation stages attaining 40.35 kGy in total dose. The obtained results for superficial resistivity display a time annealing features and their values are proportional to the total dose.

  12. Neutron Irradiation Resistance of RAFM Steels

    SciTech Connect (OSTI)

    Gaganidze, Ermile; Dafferner, Bernhard; Aktaa, Jarir

    2008-07-01

    The neutron irradiation resistance of the reduced-activation ferritic/martensitic (RAFM) steel EUROFER97 and international reference steels (F82H-mod, OPTIFER-Ia, GA3X and MANET-I) have been investigated after irradiation in the Petten High Flux Reactor up to 16.3 dpa at different irradiation temperatures (250-450 deg. C). The embrittlement behavior and hardening are investigated by instrumented Charpy-V tests with sub-size specimens. Neutron irradiation-induced embrittlement and hardening of EUROFER97 was studied under different heat treatment conditions. Embrittlement and hardening of as-delivered EUROFER97 steel are comparable to those of reference steels. Heat treatment of EUROFER97 at a higher austenitizing temperature substantially improves the embrittlement behaviour at low irradiation temperatures. Analysis of embrittlement vs. hardening behavior of RAFM steels within a proper model in terms of the parameter C={delta}DBTT/{delta}{sigma} indicates hardening-dominated embrittlement at irradiation temperatures below 350 deg. C with 0.17 {<=} C {<=} 0.53 deg. C/MPa. Scattering of C at irradiation temperatures above 400 deg. C indicates non hardening embrittlement. A role of He in a process of embrittlement is investigated in EUROFER97 based steels, that are doped with different contents of natural B and the separated {sup 10}B-isotope (0.008-0.112 wt.%). Testing on small scale fracture mechanical specimens for determination of quasi-static fracture toughness will be also presented in a view of future irradiation campaigns. (authors)

  13. ARM - Measurement - Longwave broadband downwelling irradiance

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

    downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Longwave broadband downwelling irradiance The total diffuse and direct radiant energy, at wavelengths longer than approximately 4 {mu}m, that is being emitted downwards. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file

  14. ARM - Measurement - Longwave broadband net irradiance

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

    net irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Longwave broadband net irradiance The difference between upwelling and downwelling broadband longwave radiation. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available

  15. ARM - Measurement - Longwave broadband upwelling irradiance

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

    upwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Longwave broadband upwelling irradiance The rate at which radiant energy, at a wavelength longer than approximately 4 {mu}m, is being emitted upwards into a radiation field and transferred across a surface area (real or imaginary) in a hemisphere of directions. Categories Radiometric Instruments The above measurement is considered

  16. ARM - Measurement - Longwave narrowband upwelling irradiance

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

    narrowband upwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Longwave narrowband upwelling irradiance The total radiant energy, in a narrow band of wavelengths longer than approximately 4 {mu}m, passing through a horizontal unit area in an upward direction. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments.

  17. ARM - Measurement - Net broadband total irradiance

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

    govMeasurementsNet broadband total irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Net broadband total irradiance The difference between upwelling and downwelling, covering longwave and shortwave radiation. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each

  18. ARM - Measurement - Shortwave broadband direct downwelling irradiance

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

    direct downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband direct downwelling irradiance Radiant energy, across the wavelength range of 0.4 and 4 {mu}m, that is transferred directly from the sun to the receiver. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream

  19. ARM - Measurement - Shortwave broadband total downwelling irradiance

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

    downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband total downwelling irradiance The total diffuse and direct radiant energy that comes from some continuous range of directions, at wavelengths between 0.4 and 4 {mu}m, that is being emitted downwards. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following

  20. ARM - Measurement - Shortwave broadband total net irradiance

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

    net irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband total net irradiance The difference between upwelling and downwelling broadband shortwave radiation. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available

  1. ARM - Measurement - Shortwave narrowband diffuse downwelling irradiance

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

    downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband diffuse downwelling irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4 {mu}m, that has been scattered in the atmosphere at least once, passes through a horizontal unit area in a downward direction. Categories Radiometric Instruments The above measurement is

  2. ARM - Measurement - Shortwave narrowband diffuse upwelling irradiance

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

    upwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband diffuse upwelling irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4 {mu}m, that has been scattered in the atmosphere at least once, passes through a horizontal unit area in an upward direction. Categories Radiometric Instruments The above measurement is

  3. ARM - Measurement - Shortwave narrowband direct downwelling irradiance

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

    downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband direct downwelling irradiance The direct unscattered radiant energy from the Sun, in a narrow band of wavelengths shorter than approximately 4 {mu}m, passing through a horizontal unit area in a downward direction. Categories Radiometric Instruments The above measurement is considered scientifically relevant for

  4. ARM - Measurement - Shortwave narrowband total downwelling irradiance

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

    downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband total downwelling irradiance The rate at which radiant energy, in narrow bands of wavelengths shorter than approximately 4 {mu}m, passes through a horizontal unit area in a downward direction. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following

  5. ARM - Measurement - Shortwave narrowband total upwelling irradiance

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

    upwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband total upwelling irradiance The rate at which radiant energy, in narrow bands of wavelengths shorter than approximately 4 {mu}m, passes through a horizontal unit area in an upward direction. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments.

  6. ARM - Measurement - Shortwave spectral diffuse downwelling irradiance

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

    diffuse downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave spectral diffuse downwelling irradiance The rate at which spectrally resolved radiant energy at wavelengths shorter than approximately 4 {mu}m, that has been scattered in the atmosphere at least once, passes through a horizontal unit area in a downward direction. Categories Radiometric Instruments The above

  7. ARM - Measurement - Shortwave spectral direct normal irradiance

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

    direct normal irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave spectral direct normal irradiance The narrow spectral range of measurements coming directly from the sun whose wavelength falls within the solar range of 0.4 and 4 {mu}m. Categories Radiometric Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream

  8. Meta-analysis of high-latitude nitrogen-addition and warming studies implies ecological mechanisms overlooked by land models

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

    Bouskill, N. J.; Riley, W. J.; Tang, J. Y.

    2014-12-11

    Accurate representation of ecosystem processes in land models is crucial for reducing predictive uncertainty in energy and greenhouse gas feedbacks with the climate. Here we describe an observational and modeling meta-analysis approach to benchmark land models, and apply the method to the land model CLM4.5 with two versions of belowground biogeochemistry. We focused our analysis on the aboveground and belowground responses to warming and nitrogen addition in high-latitude ecosystems, and identified absent or poorly parameterized mechanisms in CLM4.5. While the two model versions predicted similar soil carbon stock trajectories following both warming and nitrogen addition, other predicted variables (e.g., belowgroundmore » respiration) differed from observations in both magnitude and direction, indicating that CLM4.5 has inadequate underlying mechanisms for representing high-latitude ecosystems. On the basis of observational synthesis, we attribute the model–observation differences to missing representations of microbial dynamics, aboveground and belowground coupling, and nutrient cycling, and we use the observational meta-analysis to discuss potential approaches to improving the current models. However, we also urge caution concerning the selection of data sets and experiments for meta-analysis. For example, the concentrations of nitrogen applied in the synthesized field experiments (average = 72 kg ha-1 yr-1) are many times higher than projected soil nitrogen concentrations (from nitrogen deposition and release during mineralization), which precludes a rigorous evaluation of the model responses to likely nitrogen perturbations. Overall, we demonstrate that elucidating ecological mechanisms via meta-analysis can identify deficiencies in ecosystem models and empirical experiments.« less

  9. Meta-analysis of high-latitude nitrogen-addition and warming studies imply ecological mechanisms overlooked by land models

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

    Bouskill, N. J.; Riley, W. J.; Tang, J.

    2014-08-18

    Accurate representation of ecosystem processes in land models is crucial for reducing predictive uncertainty in energy and greenhouse gas feedbacks with the atmosphere. Here we describe an observational and modeling meta-analysis approach to benchmark land models, and apply the method to the land model CLM4.5 with two versions of belowground biogeochemistry. We focused our analysis on the above and belowground high-latitude ecosystem responses to warming and nitrogen addition, and identified mechanisms absent, or poorly parameterized in CLM4.5. While the two model versions predicted similar trajectories for soil carbon stocks following both types of perturbation, other variables (e.g., belowground respiration) differedmore » from the observations in both magnitude and direction, indicating the underlying mechanisms are inadequate for representing high-latitude ecosystems. The observational synthesis attribute these differences to missing representations of microbial dynamics, characterization of above and belowground functional processes, and nutrient competition. We use the observational meta-analyses to discuss potential approaches to improving the current models (e.g., the inclusion of dynamic vegetation or different microbial functional guilds), however, we also raise a cautionary note on the selection of data sets and experiments to be included in a meta-analysis. For example, the concentrations of nitrogen applied in the synthesized field experiments (average =72 kg ha-1 yr-1) are many times higher than projected soil nitrogen concentrations (from nitrogen deposition and release during mineralization), which preclude a rigorous evaluation of the model responses to nitrogen perturbation. Overall, we demonstrate here that elucidating ecological mechanisms via meta-analysis can identify deficiencies in both ecosystem models and empirical experiments.« less

  10. 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; Pavan, Alessandro Massi

    2010-05-15

    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)

  11. Measurement of Diameter Changes during Irradiation Testing

    SciTech Connect (OSTI)

    Davis, K. L.; Knudson, D. L.; Crepeau, J. C.; Solstad, S.

    2015-03-01

    New materials are being considered for fuel, cladding, and structures in advanced and existing nuclear reactors. Such materials can experience significant dimensional and physical changes during irradiation. Currently in the US, such changes are measured by repeatedly irradiating a specimen for a specified period of time and then removing it from the reactor for evaluation. The time and labor to remove, examine, and return irradiated samples for each measurement makes this approach very expensive. In addition, such techniques provide limited data and handling may disturb the phenomena of interest. In-pile detection of changes in geometry is sorely needed to understand real-time behavior during irradiation testing of fuels and materials in high flux US Material and Test Reactors (MTRs). This paper presents development results of an advanced Linear Variable Differential Transformer-based test rig capable of detecting real-time changes in diameter of fuel rods or material samples during irradiation in US MTRs. This test rig is being developed at the Idaho National Laboratory and will provide experimenters with a unique capability to measure diameter changes associated with fuel and cladding swelling, pellet-clad interaction, and crud buildup.

  12. Review of recent irradiation-creep results

    SciTech Connect (OSTI)

    Coghlan, W.A.

    1982-05-01

    Materials deform faster under stress in the presence of irradiation by a process known as irradiation creep. This phenomenon is important to reactor design and has been the subject of a large number of experimental and theoretical investigations. The purpose of this work is to review the recent experimental results to obtain a summary of these results and to determine those research areas that require additional information. The investigations have been classified into four subgroups based on the different experimental methods used. These four are: (1) irradiation creep using stress relaxation methods, (2) creep measurements using pressurized tubes, (3) irradiation creep from constant applied load, and (4) irradiation creep experiments using accelerated particles. The similarity and the differences of the results from these methods are discussed and a summary of important results and suggested areas for research is presented. In brief, the important results relate to the dependence of creep on swelling, temperature, stress state and alloying additions. In each of these areas new results have been presented and new questions have arisen which require further research to answer. 65 references.

  13. 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

    2013-01-22

    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.

  14. 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

    2012-03-22

    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.

  15. Laboratory for Characterization of Irradiated Graphite

    SciTech Connect (OSTI)

    Karen A. Moore

    2010-03-01

    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.

  16. Horizontal modular dry irradiated fuel storage system

    DOE Patents [OSTI]

    Fischer, Larry E.; McInnes, Ian D.; Massey, John V.

    1988-01-01

    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).

  17. Separation of sodium-22 from irradiated targets

    DOE Patents [OSTI]

    Taylor, Wayne A.; Jamriska, David

    1996-01-01

    A process for selective separation of sodium-22 from an irradiated target including dissolving an irradiated target to form a first solution, contacting the first solution with hydrated antimony pentoxide to selectively separate sodium-22 from the first solution, separating the hydrated antimony pentoxide including the separated sodium-22 from the first solution, dissolving the hydrated antimony pentoxide including the separated sodium-22 in a mineral acid to form a second solution, and, separating the antimony from the sodium-22 in the second solution.

  18. Fission gas retention in irradiated metallic fuel

    SciTech Connect (OSTI)

    Fenske, G.R.; Gruber, E.E.; Kramer, J.M.

    1987-01-01

    Theoretical calculations and experimental measurements of the quantity of retained fission gas in irradiated metallic fuel (U-5Fs) are presented. The calculations utilize the Booth method to model the steady-state release of gases from fuel grains and a simplified grain-boundary gas model to predict the gas release from intergranular regions. The quantity of gas retained in as-irradiated fuel was determined by collecting the gases released from short segments of EBR-II driver fuel that were melted in a gas-tight furnace. Comparison of the calculations to the measurements shows quantitative agreement with both the magnitude and the axial variation of the retained gas content.

  19. ARM - Measurement - Shortwave broadband direct normal irradiance

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

    normal irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband direct normal irradiance The rate at which radiant energy in broad bands of wavelengths shorter than approximately 4{mu}m, that comes directly from the Sun without being scattered or absorbed in the atmosphere, passes through a unit area perpendicular to the direction from the Sun. Categories Radiometric Instruments

  20. ARM - Measurement - Shortwave broadband total upwelling irradiance

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

    upwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave broadband total upwelling irradiance The rate at which radiant energy, at a wavelength between 0.4 and 4 {mu}m, is being emitted upwards into a radiation field and transferred across a surface area (real or imaginary) in a hemisphere of directions. Categories Radiometric Instruments The above measurement is considered

  1. ARM - Measurement - Shortwave narrowband direct normal irradiance

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

    normal irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave narrowband direct normal irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4{mu}m, that comes directly from the Sun without being scattered or absorbed in the atmosphere, passes through a unit area perpendicular to the direction from the Sun. Categories Radiometric Instruments

  2. ARM - Measurement - Shortwave spectral total downwelling irradiance

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

    total downwelling irradiance ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Shortwave spectral total downwelling irradiance The rate at which radiant energy, at specrally-resolved wavelengths between 0.4 and 4 {mu}m, is being emitted upwards and downwards into a radiation field and transferred across a surface area (real or imaginary) in a hemisphere of directions. Categories Radiometric Instruments

  3. Neutron Spectrum Measurements from Irradiations at NCERC

    SciTech Connect (OSTI)

    Jackman, Kevin Richard; Mosby, Michelle A.; Bredeweg, Todd Allen; Hutchens, Gregory Joe; White, Morgan Curtis

    2015-04-15

    Several irradiations have been conducted on assemblies (COMET/ZEUS and Flattop) at the National Criticality Experiments Research Center (NCERC) located at the Nevada National Security Site (NNSS). Configurations of the assemblies and irradiated materials changed between experiments. Different metallic foils were analyzed using the radioactivation method by gamma-ray spectrometry to understand/characterize the neutron spectra. Results of MCNP calculations are shown. It was concluded that MCNP simulated spectra agree with experimental measurements, with the caveats that some data are limited by statistics at low-energies and some activation foils have low activities.

  4. Fast modulations of pulsating proton aurora related to subpacket structures of Pc1 geomagnetic pulsations at subauroral latitudes

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

    Ozaki, M.; Shiokawa, K.; Miyoshi, Y.; Kataoka, R.; Yagitani, S.; Inoue, T.; Ebihara, Y.; Jun, C. -W; Nomura, R.; Sakaguchi, K.; et al

    2016-08-14

    To understand the role of electromagnetic ion cyclotron (EMIC) waves in determining the temporal features of pulsating proton aurora (PPA) via wave-particle interactions at subauroral latitudes, high-time-resolution (1/8 s) images of proton-induced N2>+ emissions were recorded using a new electron multiplying charge-coupled device camera, along with related Pc1 pulsations on the ground. The observed Pc1 pulsations consisted of successive rising-tone elements with a spacing for each element of 100 s and subpacket structures, which manifest as amplitude modulations with a period of a few tens of seconds. In accordance with the temporal features of the Pc1 pulsations, the auroral intensitymore » showed a similar repetition period of 100 s and an unpredicted fast modulation of a few tens of seconds. Furthermore, these results indicate that PPA is generated by pitch angle scattering, nonlinearly interacting with Pc1/EMIC waves at the magnetic equator.« less

  5. Understanding the Irradiation Behavior of Zirconium Carbide

    SciTech Connect (OSTI)

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

    2013-10-11

    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

  6. Continuous wave laser irradiation of explosives

    SciTech Connect (OSTI)

    McGrane, Shawn D.; Moore, David S.

    2010-12-01

    Quantitative measurements of the levels of continuous wave (CW) laser light that can be safely applied to bare explosives during contact operations were obtained at 532 nm, 785 nm, and 1550 nm wavelengths. A thermal camera was used to record the temperature of explosive pressed pellets and single crystals while they were irradiated using a measured laser power and laser spot size. A visible light image of the sample surface was obtained before and after the laser irradiation. Laser irradiation thresholds were obtained for the onset of any visible change to the explosive sample and for the onset of any visible chemical reaction. Deflagration to detonation transitions were not observed using any of these CW laser wavelengths on single crystals or pressed pellets in the unconfined geometry tested. Except for the photochemistry of DAAF, TATB and PBX 9502, all reactions appeared to be thermal using a 532 nm wavelength laser. For a 1550 nm wavelength laser, no photochemistry was evident, but the laser power thresholds for thermal damage in some of the materials were significantly lower than for the 532 nm laser wavelength. No reactions were observed in any of the studied explosives using the available 300 mW laser at 785 nm wavelength. Tables of laser irradiance damage and reaction thresholds are presented for pressed pellets of PBX9501, PBX9502, Composition B, HMX, TATB, RDX, DAAF, PETN, and TNT and single crystals of RDX, HMX, and PETN for each of the laser wavelengths.

  7. Strain engineering in graphene by laser irradiation

    SciTech Connect (OSTI)

    Papasimakis, N.; Mailis, S.; Huang, C. C.; Al-Saab, F.; Hewak, D. W.; Luo, Z.; Shen, Z. X.

    2015-02-09

    We demonstrate that the Raman spectrum of graphene on lithium niobate can be controlled locally by continuous exposure to laser irradiation. We interpret our results in terms of changes to doping and mechanical strain and show that our observations are consistent with light-induced gradual strain relaxation in the graphene layer.

  8. EFFECT OF FAST NEUTRON IRRADIATION ON SINTERED ALUMINA AND MAGNESIA...

    Office of Scientific and Technical Information (OSTI)

    IRRADIATION; LATTICES; MAGNESIUM OXIDES; MONOCRYSTALS; NEUTRON FLUX; RADIATION DOSES; RADIATION EFFECTS; SINTERED MATERIALS; TEMPERATURE; THERMAL CONDUCTIVITY ALUMINUM OXIDES

  9. Lanai high-density irradiance sensor network for characterizing...

    Office of Scientific and Technical Information (OSTI)

    deployment of an autonomous irradiance monitoring system based on wireless mesh ... SYSTEMS; DESIGN; FORECASTING; HAWAII; MONITORING; PERFORMANCE; PYRANOMETERS; RADIANT ...

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

    SciTech Connect (OSTI)

    Not Listed

    2013-04-01

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

  11. Low Dose Irradiation Facility | Savannah River Ecology Laboratory

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

    Low Dose Irradiation Facility (LoDIF) The LoDIF is a unique facility designed to evaluate the impact of chronic, low-level radiation exposure on aquatic organisms. The facility is an array of 40 outdoor mesocosms equipped with cesium-137 irradiation sources or unexposed controls. Irradiation sources provide three biologically relevant levels of exposure: 2, 20, and 200 mGy/d mean exposure. Mesocosms are arranged into eight blocks, with five mesocosms per block (three levels of irradiation and

  12. Irradiation creep of various ferritic alloys irradiated {approximately}400 C in the PFR and FFTF reactors

    SciTech Connect (OSTI)

    Toloczko, M.B.; Garner, F.A.; Eiholzer, C.R.

    1998-03-01

    Three ferritic alloys were irradiated in two fast reactors to doses of 50 dpa or more at temperatures near 400 C. One martensitic alloy, HT9, was irradiated in both the FFTF and PFR reactors. PFR is the Prototype Fast Reactor in Dourneay, Scotland, and FFTF is the Fast Flux Test Facility in Richland, WA. D57 is a developmental alloy that was irradiated in PFR only, and MA957 is a Y{sub 2}O{sub 3} dispersion-hardened ferritic alloy that was irradiated only in FFTF. These alloys exhibited little or no void swelling at {approximately}400 C. Depending on the alloy starting condition, these steels develop a variety of non-creep strains early in the irradiation that are associated with phase changes. Each of these alloys creeps at a rate that is significantly lower than that of austenitic steels irradiated in the same experiments. The creep compliance for ferritic alloys in general appears to be {approximately}0.5 {times} 10{sup {minus}6} MPa{sup {minus}1} dpa{sup {minus}1}, independent of both composition and starting state. The addition of Y{sub 2}O{sub 3} as a dispersoid does not appear to change the creep behavior.

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

    SciTech Connect (OSTI)

    Matlack, Katie; Kim, J-Y.; Wall, J.J.; Jacobs, L.J.; Sokolov, Mikhail A

    2014-05-01

    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.

  14. Advanced Numerical Model for Irradiated Concrete

    SciTech Connect (OSTI)

    Giorla, Alain B.

    2015-03-01

    In this report, we establish a numerical model for concrete exposed to irradiation to address these three critical points. The model accounts for creep in the cement paste and its coupling with damage, temperature and relative humidity. The shift in failure mode with the loading rate is also properly represented. The numerical model for creep has been validated and calibrated against different experiments in the literature [Wittmann, 1970, Le Roy, 1995]. Results from a simplified model are shown to showcase the ability of numerical homogenization to simulate irradiation effects in concrete. In future works, the complete model will be applied to the analysis of the irradiation experiments of Elleuch et al. [1972] and Kelly et al. [1969]. This requires a careful examination of the experimental environmental conditions as in both cases certain critical information are missing, including the relative humidity history. A sensitivity analysis will be conducted to provide lower and upper bounds of the concrete expansion under irradiation, and check if the scatter in the simulated results matches the one found in experiments. The numerical and experimental results will be compared in terms of expansion and loss of mechanical stiffness and strength. Both effects should be captured accordingly by the model to validate it. Once the model has been validated on these two experiments, it can be applied to simulate concrete from nuclear power plants. To do so, the materials used in these concrete must be as well characterized as possible. The main parameters required are the mechanical properties of each constituent in the concrete (aggregates, cement paste), namely the elastic modulus, the creep properties, the tensile and compressive strength, the thermal expansion coefficient, and the drying shrinkage. These can be either measured experimentally, estimated from the initial composition in the case of cement paste, or back-calculated from mechanical tests on concrete. If some

  15. Ion Irradiation of Carbon Nanotubes: a STM Study

    SciTech Connect (OSTI)

    Osvath, Z.; Vertesy, G.; Horvath, Z. E.; Gyulai, J.; Biro, L. P.

    2009-03-10

    Multi-walled carbon nanotubes irradiated with Ar{sup +} ions of low (5x10{sup 11} ions/cm{sup 2}) and high (10{sup 15} ions/cm{sup 2}) fluences were investigated by STM. Contrary to the case of low fluence irradiation, the defects produced during the high fluence irradiation could not be observed individually, and the surface of nanotubes became rough. Irradiated nanotubes could be easily bent by the STM tip. However, some nanotubes parts could not be moved, which suggest that these parts were bound to the substrate during irradiation.

  16. Nanodot formation induced by femtosecond laser irradiation

    SciTech Connect (OSTI)

    Abere, M. J.; Kang, M.; Goldman, R. S.; Yalisove, S. M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Chen, C. [Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109 (United States); Rittman, D. R. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States); Phillips, J. D. [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States); Torralva, B. [Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2014-10-20

    The femtosecond laser generation of ZnSe nanoscale features on ZnSe surfaces was studied. Irradiation with multiple exposures produces 10100?nm agglomerations of nanocrystalline ZnSe while retaining the original single crystal structure of the underlying material. The structure of these nanodots was verified using a combination of scanning transmission electron microscopy, scanning electron microscopy, and atomic force microscopy. The nanodots continue to grow hours after irradiation through a combination of bulk and surface diffusion. We suggest that in nanodot formation the result of ultrafast laser induced point defect formation is more than an order of magnitude below the ZnSe ultrafast melt threshold fluence. This unique mechanism of point defect injection will be discussed.

  17. Forward and reverse characteristics of irradiated MOSFETs

    SciTech Connect (OSTI)

    Paccagnella, A.; Ceschia, M.; Verzellesi, G.; Dalla Betta, G.F.; Soncini, G.; Bellutti, P.; Fuochi, P.G.

    1996-06-01

    pMOSFETs biased with V{sub gs} < V{sub gd} during Co{sup 60} {gamma} irradiation have shown substantial differences between the forward and reverse subthreshold characteristics, induced by a non-uniform charge distribution in the gate oxide. Correspondingly, modest differences have been observed in the over-threshold I-V characteristics. After irradiation, the forward subthreshold curves can shift at higher or lower gate voltages than the reverse ones. The former behavior has been observed in long-channel devices, in agreement with the classical MOS theory and numerical simulations. The latter result has been obtained in short-channel devices, and it has been correlated to a parasitic punch-through conduction mechanism.

  18. Fractionated total body irradiation for metastatic neuroblastoma

    SciTech Connect (OSTI)

    Kun, L.E.; Casper, J.T.; Kline, R.W.; Piaskowski, V.D.

    1981-11-01

    Twelve patients over one year old with neuroblastoma (NBL) metastatic to bone and bone marrow entered a study of adjuvant low-dose, fractionated total body irradiation (TBI). Six children who achieved a ''complete clinical response'' following chemotherapy (cyclophosphamide and adriamycin) and surgical resection of the abdominal primary received TBI (10 rad/fraction to totals of 100-120 rad/10-12 fx/12-25 days). Two children received concurrent local irradiation for residual abdominal tumor. The intervals from cessation of chemotherapy to documented progression ranged from 2-16 months, not substatially different from patients receiving similar chemotherapy and surgery without TBI. Three additional children with progressive NBL received similar TBI (80-120 rad/8-12 fx) without objective response.

  19. Neutron irradiation induced amorphization of silicon carbide

    SciTech Connect (OSTI)

    Snead, L.L.; Hay, J.C.

    1998-09-01

    This paper provides the first known observation of silicon carbide fully amorphized under neutron irradiation. Both high purity single crystal hcp and high purity, highly faulted (cubic) chemically vapor deposited (CVD) SiC were irradiated at approximately 60 C to a total fast neutron fluence of 2.6 {times} 10{sup 25} n/m{sup 2}. Amorphization was seen in both materials, as evidenced by TEM, electron diffraction, and x-ray diffraction techniques. Physical properties for the amorphized single crystal material are reported including large changes in density ({minus}10.8%), elastic modulus as measured using a nanoindentation technique ({minus}45%), hardness as measured by nanoindentation ({minus}45%), and standard Vickers hardness ({minus}24%). Similar property changes are observed for the critical temperature for amorphization at this neutron dose and flux, above which amorphization is not possible, is estimated to be greater than 130 C.

  20. LANGEVIN DYNAMICS OF THE TWO STAGE MELTING TRANSITION OF VORTEX MATTER IN Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} IN THE PRESENCE OF STRAIGHT AND OF TILTED COLUMNAR DEFECTS

    SciTech Connect (OSTI)

    GOLDSCHMIDT, YADIN Y.; LIU, Jin-Tao

    2007-08-07

    In this paper we use London Langevin molecular dynamics simulations to investigate the vortex matter melting transition in the highly anisotropic high-temperature superconductor material Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}#14; in the presence of low concentration of columnar defects (CDs). We reproduce with further details our previous results obtained by using Multilevel Monte Carlo simulations that showed that the melting of the nanocrystalline vortex matter occurs in two stages: a first stage melting into nanoliquid vortex matter and a second stage delocalization transition into a homogeneous liquid. Furthermore, we report on new dynamical measurements in the presence of a current that identifies clearly the irreversibility line and the second stage delocalization transition. In addition to CDs aligned along the c-axis we also simulate the case of tilted CDs which are aligned at an angle with respect to the applied magnetic field. Results for CDs tilted by 45{degree} with respect to c-axis show that the locations of the melting and delocalization transitions are not affected by the tilt when the ratio of flux lines to CDs remains constant. On the other hand we argue that some dynamical properties and in particular the position of the irreversibility line should be affected.

  1. Total lymphoid irradiation for multiple sclerosis

    SciTech Connect (OSTI)

    Devereux, C.K.; Vidaver, R.; Hafstein, M.P.; Zito, G.; Troiano, R.; Dowling, P.C.; Cook, S.D.

    1988-01-01

    Although chemical immunosuppression has been shown to benefit patients with chronic progressive multiple sclerosis (MS), it appears that chemotherapy has an appreciable oncogenic potential in patients with multiple sclerosis. Accordingly, we developed a modified total lymphoid irradiation (TLI) regimen designed to reduce toxicity and applied it to a randomized double blind trial of TLI or sham irradiation in MS. Standard TLI regimens were modified to reduce dose to 1,980 rad, lowering the superior mantle margin to midway between the thyroid cartilage and angle of the mandible (to avert xerostomia) and the lower margin of the mantle field to the inferior margin of L1 (to reduce gastrointestinal toxicity by dividing abdominal radiation between mantle and inverted Y), limiting spinal cord dose to 1,000 rad by custom-made spine blocks in the mantle and upper 2 cm of inverted Y fields, and also protecting the left kidney even if part of the spleen were shielded. Clinical efficacy was documented by the less frequent functional scale deterioration of 20 TLI treated patients with chronic progressive MS compared to to 20 sham-irradiated progressive MS patients after 12 months (16% versus 55%, p less than 0.03), 18 months (28% versus 63%, p less than 0.03), and 24 months (44% versus 74%, N.S.). Therapeutic benefit during 3 years follow-up was related to the reduction in lymphocyte count 3 months post-irradiation (p less than 0.02). Toxicity was generally mild and transient, with no instance of xerostomia, pericarditis, herpes zoster, or need to terminate treatment in TLI patients. However, menopause was induced in 2 patients and staphylococcal pneumonia in one.

  2. Climatic change due to solar irradiance changes

    SciTech Connect (OSTI)

    Wigley, T.M.L.; Raper, S.C.B. )

    1990-11-01

    Solar irradiance reconstructions back to 1874 are used to estimate the effect of the Sun on global-mean temperature. The importance of the history effect of the Sun on global-mean temperature. The importance of the history effect, whereby recent temperature changes may be influenced significantly by past forcing changes, is evaluated. Modelled temperature changes are shown to be relatively insensitive to model uncertainties. The overall range of modelled temperature variations is extremely small, 0.05C.

  3. Comparison of Diffuse Shortwave Irradiance Measurements

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

    Diffuse Shortwave Irradiance Measurements J. J. Michalsky and J. Schlemmer Atmospheric Sciences Research Center State University of New York Albany, New York B. C. Bush, S. Leitner, D. Marsden, and F. P. J. Valero Scripps Institution of Oceanography University of California, San Diego La Jolla, California R. Dolce and A. Los Kipp & Zonen, Inc. Bohemia, New York and Delft The Netherlands E. G. Dutton Climate Monitoring and Diagnostics Laboratory National Oceanic and Atmospheric Administration

  4. Effects of the shape of the foil corners on the irradiation performance of U10Mo alloy based monolithic mini-plates

    SciTech Connect (OSTI)

    Ozaltun, Hakan; Medvedev, Pavel G

    2015-06-01

    Monolithic plate-type fuel is a fuel form being developed for high performance research and test reactors to minimize the use of enriched material. These fuel elements are comprised of a high density, low enrichment, U-Mo alloy based fuel foil, sandwiched between Zirconium liners and encapsulated in Aluminum cladding. The use of a high density fuel in a foil form presents a number of fabrication and operational concerns, such as: foil centering, flatness of the foil, fuel thickness variation, geometrical tilting, foil corner shape etc. To benchmark this new design, effects of various geometrical and operational variables on irradiation performance have been evaluated. As a part of these series of sensitivity studies, the shape of the foil corners were studied. To understand the effects of the corner shapes of the foil on thermo-mechanical performance of the plates, a behavioral model was developed for a selected plate from RERTR-12 experiments (Plate L1P785). Both fabrication and irradiation processes were simulated. Once the thermo-mechanical behavior the plate is understood for the nominal case, the simulations were repeated for two additional corner shapes to observe the changes in temperature, displacement and stress-strain fields. The results from the fabrication simulations indicated that the foil corners do not alter the post-fabrication stress-strain magnitudes. Furthermore, the irradiation simulations revealed that post-fabrication stresses of the foil would be relieved very quickly in operation. While, foils with chamfered and filleted corners yielded stresses with comparable magnitudes, they are slightly lower in magnitudes, and provided a more favorable mechanical response compared with the foil with sharp corners.

  5. Irradiation Environment of the Materials Test Station

    SciTech Connect (OSTI)

    Pitcher, Eric John

    2012-06-21

    Conceptual design of the proposed Materials Test Station (MTS) at the Los Alamos Neutron Science Center (LANSCE) is now complete. The principal mission is the irradiation testing of advanced fuels and materials for fast-spectrum nuclear reactor applications. The neutron spectrum in the fuel irradiation region of MTS is sufficiently close to that of fast reactor that MTS can match the fast reactor fuel centerline temperature and temperature profile across a fuel pellet. This is an important characteristic since temperature and temperature gradients drive many phenomena related to fuel performance, such as phase stability, stoichiometry, and fission product transport. The MTS irradiation environment is also suitable in many respects for fusion materials testing. In particular, the rate of helium production relative to atomic displacements at the peak flux position in MTS matches well that of fusion reactor first wall. Nuclear transmutation of the elemental composition of the fusion alloy EUROFER97 in MTS is similar to that expected in the first wall of a fusion reactor.

  6. The spectral irradiance traceability chain at PTB

    SciTech Connect (OSTI)

    Sperfeld, P.; Pape, S.; Nevas, S.

    2013-05-10

    Spectral irradiance is a fundamental radiometric unit. Its application to measurement results requires qualified traceability to basic units of the international system of units (Systeme international d'unites, SI). The Physikalisch-Technische Bundesanstalt (PTB) is amongst other national metrological institutes (NMIs) responsible for the realization, maintenance and dissemination of various radiometric and photometric units based on and traceable to national standards. The unit of spectral irradiance is realized and represented by a blackbody-radiator as the national primary standard of the PTB. Based on Planck's radiation law, the irradiance is calculated and realized for any wavelength taking into account the exact knowledge of the radiation temperature and the geometrical parameters. Using a double-monochromator-based spectroradiometer system, secondary standard lamps can be calibrated by direct comparison to the blackbody-radiator (substitution method). These secondary standard lamps are then used at the PTB to calibrate standard lamps of customers. The customers themselves use these so-called transfer standards to calibrate their working standard lamps. These working standards are then used to calibrate own spectroradiometers or sources. This rather complex calibration chain is a common procedural method that for the customers generally leads to satisfying measurement results on site. Nevertheless, the standard lamps in use have to fulfill highest requirements concerning stability and reproducibility. Only this allows achieving comparably low transfer measurement uncertainties, which occur at each calibration step. Thus, the PTB is constantly investigating the improvement and further development of transfer standards and measurement methods for various spectral regions. The realization and dissemination of the spectral irradiance using the blackbody-radiator at the PTB is accomplished with worldwide approved minimized measurement uncertainties confirmed by

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

    SciTech Connect (OSTI)

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

    2007-03-26

    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.

  8. Post-irradiation-examination of irradiated fuel outside the hot cell

    SciTech Connect (OSTI)

    Dawn E. Janney; Adam B. Robinson; Thomas P. O'Holleran; R. Paul Lind; Marc Babcock; Laurence C. Brower; Julie Jacobs; Pamela K. Hoggan

    2007-09-01

    Because of their high radioactivity, irradiated fuels are commonly examined in a hot cell. However, the Idaho National Laboratory (INL) has recently investigated irradiated U-Mo-Al metallic fuel from the Reduced Enrichment for Research and Test Reactors (RERTR) project using a conventional unshielded scanning electron microscope outside a hot cell. This examination was possible because of a two-step sample-preparation approach in which a small volume of fuel was isolated in a hot cell and shielding was introduced during later stages of sample preparation. The resulting sample contained numerous sample-preparation artifacts but allowed analysis of microstructures from selected areas.

  9. Graphitization of polymer surfaces by scanning ion irradiation

    SciTech Connect (OSTI)

    Koval, Yuri [Department of Physics, Universitt Erlangen-Nrnberg, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

    2014-10-20

    Graphitization of polymer surfaces was performed by low-energy Ar{sup +} and He{sup +} ion irradiation. A method of scanning irradiation was implemented. It was found that by scanning ion irradiation, a significantly higher electrical conductivity in the graphitized layers can be achieved in comparison with a conventional broad-beam irradiation. The enhancement of the conductance becomes more pronounced for narrower and better collimated ion beams. In order to analyze these results in more detail, the temperature dependence of conductance of the irradiated samples was investigated. The results of measurements are discussed in terms of weak localization corrections to conductance in disordered metals. The observed effects can be explained by enlargement of graphitic patches, which was achieved with the scanning ion irradiation method.

  10. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    Irradiation Effects on Human Cortical Bone Fracture Behavior Irradiation Effects on Human Cortical Bone Fracture Behavior Print Wednesday, 28 July 2010 00:00 Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic framework to understand the changes taking place 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/or

  11. DECONTAMINATION OF NEUTRON-IRRADIATED REACTOR FUEL

    DOE Patents [OSTI]

    Buyers, A.G.; Rosen, F.D.; Motta, E.E.

    1959-12-22

    A pyrometallurgical method of decontaminating neutronirradiated reactor fuel is presented. In accordance with the invention, neutron-irradiated reactor fuel may be decontaminated by countercurrently contacting the fuel with a bed of alkali and alkaine fluorides under an inert gas atmosphere and inductively melting the fuel and tracking the resulting descending molten fuel with induction heating as it passes through the bed. By this method, a large, continually fresh surface of salt is exposed to the descending molten fuel which enhances the efficiency of the scrubbing operation.

  12. Irradiation-induced effects of proton irradiation on zirconium carbides with different stoichiometries

    SciTech Connect (OSTI)

    Y. Huang; B.R. Maier; T.R. Allen

    2014-10-01

    Zirconium carbide (ZrC) is being considered for utilization in deep burn TRISO fuel particles for hightemperature, gas-cooled reactors. Zirconium carbide has a cubic B1 type crystal structure along with a very high melting point (3420 ?C), exceptional hardness and good thermal and electrical conductivities. Understanding the ZrC irradiation response is crucial for establishing ZrC as an alternative component in TRISO fuel. Until now, very few studies on irradiation effects on ZrC have been released and fundamental aspects of defect evolution and kinetics are not well understood although some atomistic simulations and phenomenological studies have been performed. This work was carried out to understand the damage evolution in float-zone refined ZrC with different stoichiometries. Proton irradiations at 800 ?C up to doses of 3 dpa were performed on ZrCx (where x ranges from 0.9 to 1.2) to investigate the damage evolution. The irradiation-induced defects, such as density of dislocation loops, at different stoichiometries and doses which were characterized by transmission electron microscopy (TEM) is presented and discussed.

  13. 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

    2014-10-01

    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 443C 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 460C 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.

  14. PRODUCING SATELLITE-DERIVED IRRADIANCES IN COMPLEX ARID TERRAIN

    Open Energy Info (EERE)

    the corrected monthly maps (see Fig. 3). 4. DISCUSSION We have presented a robust, straightforward two-step approach to correct irradiance estimated from weather satellites'...

  15. Inhalation radiotoxicity of irradiated thorium as a heavy water...

    Office of Scientific and Technical Information (OSTI)

    thorium as a heavy water reactor fuel Citation Details In-Document Search Title: Inhalation radiotoxicity of irradiated thorium as a heavy water reactor fuel The online ...

  16. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    ... Specifically, at the nanoscale, irradiation leads to a marked increase in collagen cross-linking and molecular damage (assessed using Raman spectroscopy), resulting in a loss in ...

  17. Solar spectral irradiance changes during cycle 24 (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Title: Solar spectral irradiance changes during cycle 24 We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow ...

  18. Center for Materials at Irradiation and Mechanical Extremes:...

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

    a Cu 10 nm nanocrystalline sample being uni-axial compressed to strain of 20% and then stress released. Irradiation Extremes Thrust Traditional structural materials degrade and...

  19. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic...

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

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

    of hydrogen-doped zircaloy cladding in High Flux Isotope Reactor (HFIR); 2) mechanical properties of first batch of cladding irradiated in HFIR; and, 3) initiation of ...

  1. Emulation of reactor irradiation damage using ion beams

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

    Was, G. S.; Jiao, Z.; Getto, E.; Sun, K.; Monterrosa, A. M.; Maloy, S. A.; Anderoglu, O.; Sencer, B. H.; Hackett, M.

    2014-06-14

    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,more » 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 irradiation 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 irradiation establishes the capability of tailoring ion irradiation to emulate the reactor-irradiated microstructure.« less

  2. CRYSTAL STRUCTURE OF OXIDES AND THEIR NEUTRON IRRADIATION BEHAVIOR...

    Office of Scientific and Technical Information (OSTI)

    CRYSTAL STRUCTURE OF OXIDES AND THEIR NEUTRON IRRADIATION BEHAVIOR AT 80 DEG C Citation ... Country of Publication: Country unknownCode not available Language: French Subject: ...

  3. Emulation of reactor irradiation damage using ion beams

    SciTech Connect (OSTI)

    Was, G. S.; Jiao, Z.; Getto, E.; Sun, K.; Monterrosa, A. M.; Maloy, S. A.; Anderoglu, O.; Sencer, B. H.; Hackett, M.

    2014-06-14

    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 irradiation 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 irradiation establishes the capability of tailoring ion irradiation to emulate the reactor-irradiated microstructure.

  4. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    Irradiation Effects on Human Cortical Bone Fracture Behavior Print Human bone is strong but still fallible. To better predict fracturing in bone, researchers need a mechanistic ...

  5. Center for Materials at Irradiation and Mechanical Extremes:...

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

    (CINT), Physical Synthesis Lab: J. Kevin Baldwin LANL Technologist Ion Beam Materials Lab: Yongqiang Wang LANL Scientist Irradiation Thrust Electron Microscopy Lab: Rob...

  6. Irradiation Programs and Test Plans to Assess High-Fluence Irradiation Assisted Stress Corrosion Cracking Susceptibility.

    SciTech Connect (OSTI)

    Teysseyre, Sebastien

    2015-03-01

    . Irradiation assisted stress corrosion cracking (IASCC) is a known issue in current reactors. In a 60 year lifetime, reactor core internals may experience fluence levels up to 15 dpa for boiling water reactors (BWR) and 100+ dpa for pressurized water reactors (PWR). To support a safe operation of our fleet of reactors and maintain their economic viability it is important to be able to predict any evolution of material behaviors as reactors age and therefore fluence accumulated by reactor core component increases. For PWR reactors, the difficulty to predict high fluence behavior comes from the fact that there is not a consensus of the mechanism of IASCC and that little data is available. It is however possible to use the current state of knowledge on the evolution of irradiated microstructure and on the processes that influences IASCC to emit hypotheses. This report identifies several potential changes in microstructure and proposes to identify their potential impact of IASCC. The susceptibility of a component to high fluence IASCC is considered to not only depends on the intrinsic IASCC susceptibility of the component due to radiation effects on the material but to also be related to the evolution of the loading history of the material and interaction with the environment as total fluence increases. Single variation type experiments are proposed to be performed with materials that are representative of PWR condition and with materials irradiated in other conditions. To address the lack of IASCC propagation and initiation data generated with material irradiated in PWR condition, it is proposed to investigate the effect of spectrum and flux rate on the evolution of microstructure. A long term irradiation, aimed to generate a well-controlled irradiation history on a set on selected materials is also proposed for consideration. For BWR, the study of available data permitted to identify an area of concern for long term performance of component. The efficiency of

  7. High temperature annealing of ion irradiated tungsten

    SciTech Connect (OSTI)

    Ferroni, Francesco; Yi, Xiaoou; Fitzgerald, Steven P.; Edmondson, Philip D.; Roberts, Steve G.

    2015-03-21

    In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500°C, 1014 W+/cm2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View the MathML source and were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding Ea=1.34±0.2 eV for the 700–1100°C range.

  8. Hafnium radioisotope recovery from irradiated tantalum

    DOE Patents [OSTI]

    Taylor, Wayne A.; Jamriska, David J.

    2001-01-01

    Hafnium is recovered from irradiated tantalum by: (a) contacting the irradiated tantalum with at least one acid to obtain a solution of dissolved tantalum; (b) combining an aqueous solution of a calcium compound with the solution of dissolved tantalum to obtain a third combined solution; (c) precipitating hafnium, lanthanide, and insoluble calcium complexes from the third combined solution to obtain a first precipitate; (d) contacting the first precipitate of hafnium, lanthanide and calcium complexes with at least one fluoride ion complexing agent to form a fourth solution; (e) selectively adsorbing lanthanides and calcium from the fourth solution by cationic exchange; (f) separating fluoride ion complexing agent product from hafnium in the fourth solution by adding an aqueous solution of ferric chloride to obtain a second precipitate containing the hafnium and iron; (g) dissolving the second precipitate containing the hafnium and iron in acid to obtain an acid solution of hafnium and iron; (h) selectively adsorbing the iron from the acid solution of hafnium and iron by anionic exchange; (i) drying the ion exchanged hafnium solution to obtain hafnium isotopes. Additionally, if needed to remove residue remaining after the product is dried, dissolution in acid followed by cation exchange, then anion exchange, is performed.

  9. High temperature annealing of ion irradiated tungsten

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

    Ferroni, Francesco; Yi, Xiaoou; Arakawa, Kazuto; Fitzgerald, Steven P.; Edmondson, Philip D.; Roberts, Steve G.

    2015-03-21

    In this study, transmission electron microscopy of high temperature annealing of pure tungsten irradiated by self-ions was conducted to elucidate microstructural and defect evolution in temperature ranges relevant to fusion reactor applications (500–1200°C). Bulk isochronal and isothermal annealing of ion irradiated pure tungsten (2 MeV W+ ions, 500°C, 1014 W+/cm2) with temperatures of 800, 950, 1100 and 1400°C, from 0.5 to 8 h, was followed by ex situ characterization of defect size, number density, Burgers vector and nature. Loops with diameters larger than 2–3 nm were considered for detailed analysis, among which all loops had View the MathML source andmore » were predominantly of interstitial nature. In situ annealing experiments from 300 up to 1200°C were also carried out, including dynamic temperature ramp-ups. These confirmed an acceleration of loop loss above 900°C. At different temperatures within this range, dislocations exhibited behaviour such as initial isolated loop hopping followed by large-scale rearrangements into loop chains, coalescence and finally line–loop interactions and widespread absorption by free-surfaces at increasing temperatures. An activation energy for the annealing of dislocation length was obtained, finding Ea=1.34±0.2 eV for the 700–1100°C range.« less

  10. Optimisation of buildings' solar irradiation availability

    SciTech Connect (OSTI)

    Kaempf, Jerome Henri; Montavon, Marylene; Bunyesc, Josep; Robinson, Darren; Bolliger, Raffaele

    2010-04-15

    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

    2012-09-01

    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. Final Report on MEGAPIE Target Irradiation and Post-Irradiation Examination

    SciTech Connect (OSTI)

    Yong, Dai

    2015-06-30

    Megawatt pilot experiment (MEGAPIE) was successfully performed in 2006. One of the important goals of MEGAPIE is to understand the behaviour of structural materials of the target components exposed to high fluxes of high-energy protons and spallation neutrons in flowing LBE (liquid lead-bismuth eutectic) environment by conducting post-irradiation examination (PIE). The PIE includes four major parts: non-destructive test, radiochemical analysis of production and distribution of radionuclides produced by spallation reaction in LBE, analysis of LBE corrosion effects on structural materials, T91 and SS 316L steels, and mechanical testing of the T91 and SS 316L steels irradiated in the lower part of the target. The non-destructive test (NDT) including visual inspection and ultrasonic measurement was performed in the proton beam window area of the T91 calotte of the LBE container, the most intensively irradiated part of the MEGAPIE target. The visual inspection showed no visible failure and the ultrasonic measurement demonstrated no detectable change in thickness in the beam window area. Gamma mapping was also performed in the proton beam window area of the AlMg3 safety-container. The gamma mapping results were used to evaluate the accumulated proton fluence distribution profile, the input data for determining irradiation parameters. Radiochemical analysis of radionuclides produced by spallation reaction in LBE is to improve the understanding of the production and distribution of radionuclides in the target. The results demonstrate that the radionuclides of noble metals, 207Bi, 194Hg/Au are rather homogeneously distributed within the target, while radionuclides of electropositive elements are found to be deposited on the steel-LBE interface. The corrosion effect of LBE on the structural components under intensive irradiation was investigated by metallography. The results show that no evident corrosion damages. However, unexpected deep

  13. The microbial fate of carbon in high-latitude seas: Impact of the microbial loop on oceanic uptake of CO{sub 2}

    SciTech Connect (OSTI)

    Yager, P.L.

    1996-12-31

    This dissertation examines pelagic microbial processes in high-latitude seas, how they affect regional and global carbon cycling, and how they might respond to hypothesized changes in climate. Critical to these interests is the effect of cold temperature on bacterial activity. Also important is the extent to which marine biological processes in general impact the inorganic carbon cycle. The study area is the Northeast Water (NEW) Polynya, a seasonally-recurrent opening in the permanent ice situated over the northeastern Greenland continental shelf. This work was part of an international, multi-disciplinary research project studying carbon cycling in the coastal Arctic. The first chapter describes a simple model which links a complex marine food web to a simplified ocean and atmosphere. The second chapter investigates the inorganic carbon inventory of the summertime NEW Polynya surface waters to establish the effect of biological processes on the air-sea pCO{sub 2} gradient. The third and fourth chapters use a kinetic approach to examine microbial activities in the NEW Polynya as a function of temperature and dissolved organic substrate concentration, testing the so-called Pomeroy hypothesis that microbial activity is disproportionately reduced at low environmental temperatures owing to increased organic substrate requirements. Together, the suite of data collected on microbial activities, cell size, and grazing pressure suggest how unique survival strategies adopted by an active population of high-latitude bacteria may contribute to, rather than detract from, an efficient biological carbon pump.

  14. PROCESS FOR CONTINUOUSLY SEPARATING IRRADIATION PRODUCTS OF THORIUM

    DOE Patents [OSTI]

    Hatch, L.P.; Miles, F.T.; Sheehan, T.V.; Wiswall, R.H.; Heus, R.J.

    1959-07-01

    A method is presented for separating uranium-233 and protactinium from thorium-232 containing compositions which comprises irradiating finely divided particles of said thorium with a neutron flux to form uranium-233 and protactinium, heating the neutron-irradiated composition in a fluorine and hydrogen atmosphere to form volatile fluorides of uranium and protactinium and thereafter separating said volatile fluorides from the thorium.

  15. Identifying irradiated flours by photo-stimulated luminescence technique

    SciTech Connect (OSTI)

    Ramli, Ros Anita Ahmad; Yasir, Muhamad Samudi; Othman, Zainon; Abdullah, Wan Saffiey Wan

    2014-02-12

    Photo-stimulated luminescence (PSL) technique was used in this study to detect gamma irradiation treatment of five types of flours (corn, rice, tapioca, wheat and glutinous rice) at four different doses 0, 0.2, .05 and 1kGy. The signal level was compared with two threshold values (700 and 5000). With the exception of glutinous rice, all irradiated samples produced a strong signal above the upper threshold (5000 counts/60s). All control samples produced negative result with the signals below the lower threshold (700 counts/60s) suggesting that the samples have not been irradiated. Irradiated glutinous rice samples produced intermediate signals (700 - 5000 counts/60s) which were subsequently confirmed using calibrated PSL. The PSL signals remained stable after 90 days of storage. The findings of this study will be useful to facilitate control of food irradiation application in Malaysia.

  16. Fowler-Nordheim characteristics of electron irradiated MOS capacitors

    SciTech Connect (OSTI)

    Candelori, A.; Paccagnella, A.; Cammarata, M.; Ghidini, G.; Fuochi, P.G.

    1998-12-01

    MOS capacitors with 8 nm thick oxides have been irradiated by an 8 MeV LINAC electron beam. C-V and I-V measurements have shown a positive trapped charge, higher for irradiation performed under negative gate bias, as a consequence of preferential charge recombination at the cathodic interface. No saturation of the positive trapped charge is measured up to 20 Mrad(Si). Neutral defects induced by irradiation have been studied, by performing positive and negative Fowler-Nordheim injection. The distribution of neutral defects is similar to that of trapped holes, indicating a correlation between trapped holes and neutral defects. Electrical stresses performed after irradiation have shown that the accumulation kinetics of oxide defects is similar in both unirradiated and irradiated devices.

  17. Surface modification of multilayer graphene using Ga ion irradiation

    SciTech Connect (OSTI)

    Wang, Quan; Shao, Ying; Ge, Daohan; Ren, Naifei; Yang, Qizhi

    2015-04-28

    The effect of Ga ion irradiation intensity on the surface of multilayer graphene was examined. Using Raman spectroscopy, we determined that the irradiation caused defects in the crystal structure of graphene. The density of defects increased with the increase in dwell times. Furthermore, the strain induced by the irradiation changed the crystallite size and the distance between defects. These defects had the effect of doping the multilayer graphene and increasing its work function. The increase in work function was determined using contact potential difference measurements. The surface morphology of the multilayer graphene changed following irradiation as determined by atomic force microscopy. Additionally, the adhesion between the atomic force microscopy tip and sample increased further indicating that the irradiation had caused surface modification, important for devices that incorporate graphene.

  18. Breakdown properties of irradiated MOS capacitors

    SciTech Connect (OSTI)

    Paccagnella, A.; Candelori, A.; Milani, A.; Formigoni, E.; Ghidini, G.; Drera, D.; Pellizzer, F.; Fuochi, P.G.; Lavale, M.

    1996-12-01

    The authors have studied the effects of ionizing and non-ionizing radiation on the breakdown properties of different types of MOS capacitors, with thick (200 nm) and thin (down to 8 nm) oxides. In general, no large variations of the average breakdown field, time-to-breakdown at constant voltage, or charge-to-breakdown at constant voltage, or charge-to-breakdown values have been observed after high dose irradiation (20 Mrad(Si) 9 MeV electrons on thin and thick oxides, 17(Si) Mrad Co{sup 60} gamma and 10{sup 14} neutrons/cm{sup 2} only on thick oxides). However, some modifications of the cumulative failure distributions have been observed in few of the oxides tested.

  19. Recovery of niobium from irradiated targets

    DOE Patents [OSTI]

    Phillips, Dennis R.; Jamriska, Sr., David J.; Hamilton, Virginia T.

    1994-01-01

    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.

  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

    2009-09-01

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

    SciTech Connect (OSTI)

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

    2014-12-01

    Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor, Oak Ridge National Laboratory at reactor coolant temperatures of 50-70C to low displacement damage of 0.025 and 0.3 dpa under the framework of the US-Japan TITAN program (2007-2013). After cooling down, the HFIR neutron-irradiated 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 510? m? to reach a total ion fluence of 110? m? in order to investigate the near surface deuterium retention and saturation via nuclear reaction analysis. Final thermal desorption spectroscopy was performed to elucidate irradiation effect on total deuterium retention. Nuclear reaction analysis results showed that the maximum near surface (<5 m 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 near surface retention via nuclear reaction analysis indicated the deuterium was migrated and trapped in bulk (at least 50 m depth for 0.025 dpa and 35 m depth for 0.025 dpa) at 500 C case even in the relatively low ion fluence of 10? m?.

  2. Evaluation of global horizontal irradiance to plane-of-array irradiance models at locations across the United States

    SciTech Connect (OSTI)

    Lave, Matthew; Hayes, William; Pohl, Andrew; Hansen, Clifford W.

    2015-02-02

    We report an evaluation of the accuracy of combinations of models that estimate plane-of-array (POA) irradiance from measured global horizontal irradiance (GHI). This estimation involves two steps: 1) decomposition of GHI into direct and diffuse horizontal components and 2) transposition of direct and diffuse horizontal irradiance (DHI) to POA irradiance. Measured GHI and coincident measured POA irradiance from a variety of climates within the United States were used to evaluate combinations of decomposition and transposition models. A few locations also had DHI measurements, allowing for decoupled analysis of either the decomposition or the transposition models alone. Results suggest that decomposition models had mean bias differences (modeled versus measured) that vary with climate. Transposition model mean bias differences depended more on the model than the location. Lastly, when only GHI measurements were available and combinations of decomposition and transposition models were considered, the smallest mean bias differences were typically found for combinations which included the Hay/Davies transposition model.

  3. Early Damage Mechanisms in Nuclear Grade Graphite under Irradiation

    SciTech Connect (OSTI)

    Eapen, Dr. Jacob [North Carolina State University] [North Carolina State University; Krishna, Dr Ram [North Carolina State University] [North Carolina State University; Burchell, Timothy D [ORNL] [ORNL; Murty, Prof K.L. [North Carolina State University] [North Carolina State University

    2014-01-01

    Using Raman and X-ray photoelectron spectroscopy,we delineate the bond and defect structures in nuclear block graphite (NBG-18) under neutron and ion irradiation. The strengthening of the defect (D) peak in the Raman spectra under irradiation is attributed to an increase in the topological, sp2-hybridized defects. Using transmission electron microscopy, we provide evidence for prismatic dislocations as well as a number of basal dislocations dissociating into Shockley partials. The non-vanishing D peak in the Raman spectra, together with a generous number of dislocations, even at low irradiation doses, indicates a dislocation-mediated amorphization process in graphite.

  4. Measurement of thermal conductivity in proton irradiated silicon

    SciTech Connect (OSTI)

    Marat Khafizov; Clarissa Yablinsky; Todd Allen; David Hurley

    2014-04-01

    We investigate the influence of proton irradiation on thermal conductivity in single crystal silicon. We apply laser based modulated thermoreflectance technique to extract the change in conductivity of the thin layer damaged by proton irradiation. Unlike time domain thermoreflectance techniques that require application of a metal film, we perform our measurement on uncoated samples. This provides greater sensitivity to the change in conductivity of the thin damaged layer. Using sample temperature as a parameter provides a means to deduce the primary defect structures that limit thermal transport. We find that under high temperature irradiation the degradation of thermal conductivity is caused primarily by extended defects.

  5. Concurrent in situ ion irradiation transmission electron microscope

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

    Hattar, K.; Bufford, D. C.; Buller, D. L.

    2014-08-29

    An in situ ion irradiation transmission electron microscope has been developed and is operational at Sandia National Laboratories. This facility permits high spatial resolution, real time observation of electron transparent samples under ion irradiation, implantation, mechanical loading, corrosive environments, and combinations thereof. This includes the simultaneous implantation of low-energy gas ions (0.8–30 keV) during high-energy heavy ion irradiation (0.8–48 MeV). In addition, initial results in polycrystalline gold foils are provided to demonstrate the range of capabilities.

  6. Ion irradiation tolerance of graphene as studied by atomistic simulations

    SciTech Connect (OSTI)

    Ahlgren, E. H.; Lehtinen, O.; Kotakoski, J.; Krasheninnikov, A. V.

    2012-06-04

    As impermeable to gas molecules and at the same time transparent to high-energy ions, graphene has been suggested as a window material for separating a high-vacuum ion beam system from targets kept at ambient conditions. However, accumulation of irradiation-induced damage in the graphene membrane may give rise to its mechanical failure. Using atomistic simulations, we demonstrate that irradiated graphene even with a high vacancy concentration does not show signs of such instability, indicating a considerable robustness of graphene windows. We further show that upper and lower estimates for the irradiation damage in graphene can be set using a simple model.

  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.

    2014-05-01

    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

    2012-07-01

    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

  9. ARM - Datastreams - rphtilt

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

    basetime North latitude degreeN lat East longitude degreeE lon Surface condition Pitch angle reported by tilt table degrees pitch ( time ) Surface condition Roll angle...

  10. Small-scale irradiated fuel electrorefining

    SciTech Connect (OSTI)

    Benedict, R.W.; Krsul, J.R.; Mariani, R.D.; Park, K.; Teske, G.M.

    1993-09-01

    In support of the metallic fuel cycle development for the Integral Fast Reactor (IFR), a small scale electrorefiner was built and operated in the Hot Fuel Examination Facility (HFEF) at Argonne National Laboratory-West. The initial purpose of this apparatus was to test the single segment dissolution of irradiated metallic fuel via either direct dissolution in cadmium or anodic dissolution. These tests showed that 99.95% of the uranium and 99.99% of the plutonium was dissolved and separated from the fuel cladding material. The fate of various fission products was also measured. After the dissolution experiments, the apparatus was upgraded to stady fission product behavior during uranium electrotransport. Preliminary decontamination factors were estimated for different fission products under different processing conditions. Later modifications have added the following capabilities: Dissolution of multiple fuel segments simultaneously, electrotransport to a solid cathode or liquid cathode and actinide recovery with a chemical reduction crucible. These capabilities have been tested with unirradiated uranium-zirconium fuel and will support the Fuel Cycle Demonstration program.