National Library of Energy BETA

Sample records for diffuse downwelling irradiance

  1. ARM - Measurement - Shortwave spectral diffuse downwelling irradiance

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

    Measurement : Shortwave spectral diffuse downwelling irradiance The rate at which spectrally resolved radiant energy at wavelengths shorter than approximately 4 mum, that has ...

  2. ARM - Measurement - Shortwave broadband diffuse downwelling irradiance

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

    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 ...

  3. ARM - Measurement - Shortwave narrowband diffuse downwelling...

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

    Measurement : Shortwave narrowband diffuse downwelling irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4 mum, that has been ...

  4. ARM - Measurement - Longwave broadband downwelling irradiance

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

    Measurement : Longwave broadband downwelling irradiance The total diffuse and direct radiant energy, at wavelengths longer than approximately 4 mum, that is being emitted ...

  5. ARM - Measurement - Shortwave broadband total downwelling irradiance

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

    Measurement : Shortwave broadband total downwelling irradiance The total diffuse and direct radiant energy that comes from some continuous range of directions, at wavelengths ...

  6. ARM - Measurement - Shortwave narrowband total downwelling irradiance

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

    Send Measurement : Shortwave narrowband total downwelling irradiance The rate at which radiant energy, in narrow bands of wavelengths shorter than approximately 4 mum, passes ...

  7. ARM - Measurement - Shortwave narrowband direct downwelling irradiance

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

    Measurement : Shortwave narrowband direct downwelling irradiance The direct unscattered radiant energy from the Sun, in a narrow band of wavelengths shorter than approximately 4 ...

  8. ARM - Measurement - Shortwave spectral total downwelling irradiance

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

    Send Measurement : Shortwave spectral total downwelling irradiance The rate at which radiant energy, at specrally-resolved wavelengths between 0.4 and 4 mum, is being emitted ...

  9. ARM - Measurement - Shortwave broadband direct downwelling irradiance

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

    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 ...

  10. ARM: SIRS: derived, correction of downwelling shortwave diffuse hemispheric measurements using Dutton and full algorithm

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Laura Riihimaki

    1997-03-21

    SIRS: derived, correction of downwelling shortwave diffuse hemispheric measurements using Dutton and full algorithm

  11. 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 Earths surface covered by ocean where long-term records of these measurements are sorely needed and must be made on ships and buoys.

  12. ARM - Measurement - Shortwave narrowband diffuse upwelling irradiance

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

    Send Measurement : Shortwave narrowband diffuse upwelling irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4 mum, that has ...

  13. ARM - Instrument - noaarad

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

    irradiance Shortwave broadband diffuse downwelling irradiance Shortwave broadband direct downwelling irradiance Shortwave broadband total downwelling irradiance Shortwave...

  14. ARM - Campaign Instrument - island-guest-instruments

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

    broadband diffuse downwelling irradiance Shortwave broadband direct downwelling irradiance Shortwave broadband total downwelling irradiance Radar Doppler Radar reflectivity...

  15. ARM - Datastreams - rss

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

    Variable Shortwave spectral diffuse downwelling irradiance diffuse Shortwave spectral direct normal irradiance directnormal Shortwave spectral total downwelling irradiance...

  16. An Instrument Design Concept for Measuring Solar Diffuse Irradiance

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

    An Instrument Design Concept for Measuring Solar Diffuse Irradiance Rutledge, Charles NASA Langley Research Center Schuster, Greg NASA Langley Research Center Category: Instruments Recent effort towards the development of a diffuse horizontal solar irradiance standard group [Michalsky et.al. 2005] using well calibrated pyranometers suggested that inter-instrument differences in cosine response characteristics may be problematic. They showed a calibration method using overcast skies (an

  17. Diffuse Irradiance Study Planned for October

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

    and radiometers installed at the SGP CART site near Lamont, Oklahoma. The instruments measuring diffuse solar radiation have black sphere-shaped shades to keep direct sunlight from...

  18. Final report (Grant No. DOE DE-FG02-97ER62366) [Retrieval of cloud fraction and type using broadband diffuse and total shortwave irradiance measurements

    SciTech Connect (OSTI)

    Clothiaux, Eugene

    2001-05-17

    The primary research effort supported by Grant No. DOE DEFG02-97ER62366 titled ''Retrieval of Cloud Fraction and Type Using Broadband Diffuse and Total Shortwave Irradiance Measurements'' was application of clear-sky identification and cloud fraction estimation algorithms developed by Charles N. Long and Thomas P. Ackerman to the downwelling total, direct and diffuse shortwave irradiance measurements made at all of the central, boundary, and extended facilities of the DOE Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SOP) site. Goals of the research were finalization and publication of the two algorithms in the peer-reviewed literature and operational application of them to all of aforementioned data streams from the ARM SGP site. The clear-sky identification algorithm was published as Long and Ackerman (2000) in the Journal of Geophysical Research, while a description of the cloud fraction estimation algorithm made it to the scientific literature as Long et al. (1999) in the Proceedings of the 10th American Meteorological Association Conference on Atmospheric Radiation held in Madison, Wisconsin. The cloud fraction estimation algorithm relies on empirical relationships between the outputs of the clear-sky identification algorithm and cloud fraction; as such, the cloud fraction estimation algorithm requires significant amounts of data both to properly develop the empirical relationships and to thoroughly test them. With this perspective in mind the major focus of our research efforts in the later half of the project became the operational implementation of the clear-sky identification algorithm on DOE ARM SGP data so that we could develop the data set necessary for final tuning of the cloud fraction estimation algorithm in research extending beyond the lifetime of the project.

  19. Evidence for Stratospheric Downwelling Associated with High-Elevation Topography

    SciTech Connect (OSTI)

    Finkel, R

    2009-01-28

    The continued presence of elevated chlorine-36 in Sierra Nevada streams is commonly interpreted as residual nuclear fallout, but this prolonged storage contradicts accepted hydrologic models, which indicate much less short-term groundwater storage. Our hypothesis is that the chlorine-36 source is stratospheric downwelling during high-intensity storms by measuring beryllium-7 and -10, sodium-22, and chlorium-36 in precipitation, lake, and soil samples. These nuclides are produced in abundance in the stratosphere and, except for chlorine-36, did not occur as nuclear fallout. This project will either substantially change hydrologic models or reveal an unrecognized pathway for stratosphere-troposphere exchange. Either result will have substantial scientific impact. The test of the hypothesis is straightforward. If stratospheric downwelling occurs to the extent indicated by observed Sierran chlorine-36 levels, it should be detectable by elevated levels of beryllium-7 and -10, sodium-22, and chlorine-36 in storm precipitation. Samples will be collected from an established array of sampling locations. If elevated levels of these nuclides are not found, it would cast severe doubt on the hypothesis. In this case, Sierran hydrologic models will have to take into account high levels of long-term groundwater storage. If elevated levels of these nuclides are found in Sierran precipitation, it could only be from stratospheric input, both because nuclear fallout is no longer occurring and because beryllium-7 and -10 and sodium-22 are not produced by atmospheric nuclear tests.

  20. Measurement of temperature-dependent defect diffusion in proton-irradiated GaN(Mg, H).

    SciTech Connect (OSTI)

    Myers, Samuel Maxwell, Jr.; Fleming, Robert M.

    2005-06-01

    Deuterated p-type GaN(Mg,{sup 2}H) films were irradiated at room temperature with 1 MeV protons to create native point defects with a concentration approximately equal to the Mg doping (5 x 10{sup 19} cm{sup -3}). The samples were then annealed isothermally at a succession of temperatures while monitoring the infrared absorption due to the H local mode of the MgH defect. As the samples were annealed, the MgH absorption signal decreased and a new mode at slightly higher frequency appeared, which has been associated with the approach of a mobile nitrogen interstitial. We used the time dependence of the MgH absorption to obtain a diffusion barrier of the nitrogen interstitial in p-type GaN of 1.99 eV. This is in good agreement with theoretical calculations of nitrogen interstitial motion in GaN.

  1. Asymmetry in the Diurnal Cycle of Atmospheric Downwelling Radiation at the ARM SGP CF Site Over 1995-2001 Period

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

    Asymmetry in the Diurnal Cycle of Atmospheric Downwelling Radiation at the ARM SGP CF Site Over 1995-2001 Period A. P. Trishchenko Canada Centre for Remote Sensing Ottawa, Ontario, Canada Introduction The shape of the diurnal cycle of atmospheric downwelling radiation is an important climatic feature of cloud-radiation interactions and atmospheric properties. Adequate characterization of this diurnal cycle is critical for accurate determination of monthly and seasonal radiation budgets from a

  2. First Results of Scanning Thermal Diffusivity Microscope (STDM) Measurements on Irradiated Monolithic and Dispersion Fuel

    SciTech Connect (OSTI)

    T. K. Huber; M. K. Figg; J. R. Kennedy; A. B. Robinson; D. M. Wachs

    2012-07-01

    The thermal conductivity of the fuel material in a reactor before and during irradiation is a sensitive and fundamental parameter for thermal hydraulic calculations that are useds to correctly determine fuel heat fluxes and meat temperatures and to simulate performance of the fuel elements during operation. Several techniques have been developed to measure the thermal properties of fresh fuel to support these calculations, but it is crucial to also investigate the change of thermal properties during irradiation.

  3. ARM - Datastreams - noaaradbrw

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

    broadband total downwelling irradiance downshorthemispnearIR Shortwave broadband direct downwelling irradiance shortdirectnormal Shortwave broadband total downwelling...

  4. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

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

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Nimore » $$_{50}$$Co$$_{50}$$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.« less

  5. Investigation of defect clusters in ion-irradiated Ni and NiCo using diffuse X-ray scattering and electron microscopy

    SciTech Connect (OSTI)

    Olsen, Raina J.; Jin, Ke; Lu, Chenyang; Beland, Laurent K.; Wang, Lumin M.; Bei, Hongbin; Specht, Eliot D.; Larson, Bennett C.

    2016-01-01

    The nature of defect clusters in Ni and Ni$_{50}$Co$_{50}$ (NiCo) irradiated at room temperature with 2–16 MeV Ni ions is studied using asymptotic diffuse X-ray scattering and transmission electron microscopy (TEM). Analysis of the scattering data provides separate size distributions for vacancy and interstitial type defect clusters, showing that both types of defect clusters have a smaller size and higher density in NiCo than in Ni. Diffuse scattering results show good quantitative agreement with TEM results for cluster sizes greater than 4 nm diameter, but find that the majority of vacancy clusters are under 2 nm in NiCo, which, if not detected, would lead to the conclusion that defect density was actually lower in the alloy. Interstitial dislocation loops and stacking fault tetrahedra are identified by TEM. Lastly comparison of diffuse scattering lineshapes to those calculated for dislocation loops and SFTs indicates that most of the vacancy clusters are SFTs.

  6. Evidence That MR Diffusion Tensor Imaging (Tractography) Predicts the Natural History of Regional Progression in Patients Irradiated Conformally for Primary Brain Tumors

    SciTech Connect (OSTI)

    Krishnan, Anitha Priya; Asher, Isaac M.; Davis, Delphine; Okunieff, Paul; O'Dell, Walter G.

    2008-08-01

    Purpose: Stereotactic radiotherapy (SRT) is fast becoming the method of choice for treatment of nonsuperficial brain lesions. SRT treatment plans of malignant brain tumors typically incorporate a 20-mm isotropic margin to account for microscopic tumor spread; however, distant or progressive tumors occur outside this margin. Our hypothesis is that paths of elevated water diffusion may provide a preferred route for transport or migration of cancer cells. If our hypothesis is correct, then future SRT treatment volumes could be modified to provide elongated treatment margins along the paths of elevated water diffusion, thereby creating a biologically better treatment plan that may reduce the incidence of progression. Methods and Materials: Magnetic resonance diffusion tensor imaging (DTI) datasets were acquired on patient subjects before the appearance of >5 mm diameter progressive lesions or secondary tumors. DTI was performed using an echo-planar imaging sequence on a 1.5T clinical General Electric scanner with voxel dimensions of 0.98 x 0.98 x 6 mm. After SRT, patients were given repeated magnetic resonance imaging follow-ups at regular intervals to identify early tumor progression. When progressive disease was detected, DTIstudio and FMRIB Software Library software was used to compute paths of preferred water diffusion through the primary tumor site and the site of progression. Results: Our preliminary results on 14 patient datasets suggest a strong relationship between routes of elevated water diffusion from the primary tumor and the location of tumor progression. Conclusions: Further investigation is therefore warranted. Future work will employ more sophisticated fiber analysis in a prospective study.

  7. Year Global Normal Irradiance Direct Normal Irradiance

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

    Year Global Normal Irradiance Direct Normal Irradiance (TMY3 = 6.7) Global Horizontal Irradiance** (TMY3 = 5.43) Latitude Tilt Irradiance** Diffuse Horizontal Irradiance (TMY3 = 1.46) Peak GNI (1-hr avg) Peak DNI (1-hr avg) Peak GHI (1-hr avg) Peak Lat.Tilt (1-hr avg) TMY2 8.8 6.7 5.6 6.4 1.6 - - - - 2015 8.26 6.58 5.29 6.07 1.34 1167 1067 1090 1208 2014 8.85 7.10 5.54 6.40 1.28 1176 1083 1098 1196 2013 8.82 7.23 5.59 6.63 1.24 1192 1076 1093 1182 2012 9.17 7.41 5.69 6.65 1.21 1177 1080 1091

  8. Diffusion Tensor Magnetic Resonance Imaging Finding of Discrepant Fractional Anisotropy Between the Frontal and Parietal Lobes After Whole-Brain Irradiation in Childhood Medulloblastoma Survivors: Reflection of Regional White Matter Radiosensitivity?

    SciTech Connect (OSTI)

    Qiu Deqiang; Kwong, Dora; Chan, Godfrey; Leung, Lucullus; Khong, P.-L.

    2007-11-01

    Purpose: To test the hypothesis that fractional anisotropy (FA) is more severely reduced in white matter of the frontal lobe compared with the parietal lobe after receiving the same whole-brain irradiation dose in a cohort of childhood medulloblastoma survivors. Methods and Materials: Twenty-two medulloblastoma survivors (15 male, mean [{+-} SD] age = 12.1 {+-} 4.6 years) and the same number of control subjects (15 male, aged 12.0 {+-} 4.2 years) were recruited for diffusion tensor magnetic resonance imaging scans. Using an automated tissue classification method and the Talairach Daemon atlas, FA values of frontal and parietal lobes receiving the same radiation dose, and the ratio between them were quantified and denoted as FFA, PFA, and FA{sub f/p}, respectively. The Mann-Whitney U test was used to test for significant differences of FFA, PFA, and FA{sub f/p} between medulloblastoma survivors and control subjects. Results: Frontal lobe and parietal lobe white matter FA were found to be significantly less in medulloblastoma survivors compared with control subjects (frontal p = 0.001, parietal p = 0.026). Moreover, these differences were found to be discrepant, with the frontal lobe having a significantly larger difference in FA compared with the parietal lobe. The FA{sub f/p} of control and medulloblastoma survivors was 1.110 and 1.082, respectively (p = 0.029). Conclusion: Discrepant FA changes after the same irradiation dose suggest radiosensitivity of the frontal lobe white matter compared with the parietal lobe. Special efforts to address the potentially vulnerable frontal lobe after treatment with whole-brain radiation may be needed so as to balance disease control and treatment-related morbidity.

  9. Pyroelectric-field driven defects diffusion along c-axis in ZnO nanobelts under high-energy electron beam irradiation

    SciTech Connect (OSTI)

    Ding, Yong Liu, Ying; Niu, Simiao; Wu, Wenzhuo; Wang, Zhong Lin

    2014-10-21

    When ZnO nanobelts are exposed to a high-dose electron probe of several nanometers to hundred nanometers in diameter inside a transmission electron microscope, due to the radiolysis effect, part of oxygen atoms will be ejected into the vacuum and leaving a Zn-ion rich surface with a pit appearance at both the electron-entrance and electron-exit surfaces. At the same time, a temperature distribution is created around the electron probe due to local beam heating effect, which generates a unidirectional pyroelectric field. This pyroelectric field is strong enough to drive Zn ions moving along its positive c-axis direction as interstitial ions. In the first case, for the ZnO nanobelts with c-axis lie in their large surfaces, defects due to the aggregation of Zn interstitial ions will be formed at some distances of 3050 nm approximately along the c-axis direction from the electron beam illuminated area. Alternatively, for the ZnO nanobelts with (0001) planes as their large surfaces, the incident electron beam is along its c-axis and the generated pyroelectric field will drive the interstitial Zn-ions to aggregate at the Zn terminated (0001) surface where the local electrical potential is the lowest. Such electron beam induced damage in ZnO nanostructures is suggested as a result of Zn ion diffusion driven by the temperature gradient induced pyroelectric field along c-axis. Our study shows a radiation damage caused by electron beam in transmission electron microscopy, especially when the electron energy is high.

  10. Hierarchical diffusion

    SciTech Connect (OSTI)

    Bachas, C.P.

    1988-02-01

    We review the solution and properties of the diffusion equation in a hierarchical or ultrametric space. 11 refs.

  11. 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.

  12. Comparison of Diffuse Shortwave Irradiance Measurements

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

    components separately and adds to obtain a reference measurement. The pyranometer signal under test is ratioed to the summed components on clear days when the sun is within...

  13. 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.

  14. Solar and Infrared Radiation Station (SIRS) Handbook

    SciTech Connect (OSTI)

    Stoffel, T

    2005-07-01

    The Solar Infrared Radiation Station (SIRS) provides continuous measurements of broadband shortwave (solar) and longwave (atmospheric or infrared) irradiances for downwelling and upwelling components. The following six irradiance measurements are collected from a network of stations to help determine the total radiative flux exchange within the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility: Direct normal shortwave (solar beam) Diffuse horizontal shortwave (sky) Global horizontal shortwave (total hemispheric) Upwelling shortwave (reflected) Downwelling longwave (atmospheric infrared) Upwelling longwave (surface infrared)

  15. ARM - VAP Product - beflux1long

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

    Epoch seconds since 1970-1-1 0:00:00 0:00 basetime Longwave broadband downwelling irradiance Downwelling Longwave Hemisperic Irradiance Wm2 downlonghemisp ( time )...

  16. Diffusion bonding

    DOE Patents [OSTI]

    Anderson, Robert C.

    1976-06-22

    1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

  17. Michalsky-JJ

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

    Accuracy of Broadband Shortwave Irradiance Measurements Using the Open Silicon Channel of the MFRSR J. J. Michalsky State University of New York Albany, New York Introduction The best routine Atmospheric Radiation Measurement (ARM) Program measurement of downwelling irradiance in the total shortwave band is a sum of diffuse horizontal irradiance and the direct normal irradiance component that is incident horizontally (diffuse horizontal). The latter is obtained by multiplying the direct normal

  18. 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.

  19. 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)

  20. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, Hsu-Chi; Cheng, Yung-Sung

    1984-08-07

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  1. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, H.C.; Cheng, Y.S.

    1984-01-01

    A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

  2. The influence of mixed and phase clouds on surface shortwave irradiance during the Arctic spring

    SciTech Connect (OSTI)

    Lubin D.; Vogelmann A.

    2011-10-13

    The influence of mixed-phase stratiform clouds on the surface shortwave irradiance is examined using unique spectral shortwave irradiance measurements made during the Indirect and Semi-Direct Aerosol Campaign (ISDAC), supported by the U.S. Department of Energy Atmospheric Radiation Measurement (ARM) program. An Analytical Spectral Devices (ASD, Inc.) spectroradiometer measured downwelling spectral irradiance from 350 to 2200 nm in one-minute averages throughout April-May 2008 from the ARM Climate Research Facility's North Slope of Alaska (NSA) site at Barrow. This study examines spectral irradiance measurements made under single-layer, overcast cloud decks having geometric thickness < 3000 m. Cloud optical depth is retrieved from irradiance in the interval 1022-1033 nm. The contrasting surface radiative influences of mixed-phase clouds and liquid-water clouds are discerned using irradiances in the 1.6-{micro}m window. Compared with liquid-water clouds, mixed-phase clouds during the Arctic spring cause a greater reduction of shortwave irradiance at the surface. At fixed conservative-scattering optical depth (constant optical depth for wavelengths {lambda} < 1100 nm), the presence of ice water in cloud reduces the near-IR surface irradiance by an additional several watts-per-meter-squared. This additional reduction, or supplemental ice absorption, is typically {approx}5 W m{sup -2} near solar noon over Barrow, and decreases with increasing solar zenith angle. However, for some cloud decks this additional absorption can be as large as 8-10 W m{sup -2}.

  3. ARM: Pixels from SASHe corresponding to MFR radiometer wavelengths...

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Office of Science (SC), Biological and Environmental Research (BER) ... irradiance; Shortwave narrowband direct downwelling irradiance; Shortwave ...

  4. Radiative Flux Analysis (Dataset) | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    Sponsoring Org: USDOE Office of Science (SC), Biological and Environmental Research (BER) ... irradiance; Shortwave broadband direct downwelling irradiance; Shortwave ...

  5. ARM - Datastreams - ecmwfsfce

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

    irradiance downlr Shortwave broadband total downwelling irradiance downsr Surface skin temperature skintemp Atmospheric moisture spechumidity Horizontal wind windu...

  6. Microfabricated diffusion source

    DOE Patents [OSTI]

    Oborny, Michael C.; Frye-Mason, Gregory C.; Manginell, Ronald P.

    2008-07-15

    A microfabricated diffusion source to provide for a controlled diffusion rate of a vapor comprises a porous reservoir formed in a substrate that can be filled with a liquid, a headspace cavity for evaporation of the vapor therein, a diffusion channel to provide a controlled diffusion of the vapor, and an outlet to release the vapor into a gas stream. The microfabricated diffusion source can provide a calibration standard for a microanalytical system. The microanalytical system with an integral diffusion source can be fabricated with microelectromechanical systems technologies.

  7. 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.

  8. On Correction of Diffuse Radiation Measured by MFRSR

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

    On Correction of Diffuse Radiation Measured by MFRSR T. B. Zhuravleva Institute of Atmospheric Optics, SB RAS Tomsk, Russia M. A. Sviridenkov and P. P. Anikin A. M. Obukhov Institute of Atmospheric Physics, RAS Moscow, Russia Introduction The multi-filter rotated shadowband radiometer (MFRSR) provides spectral direct, diffuse, and total horizontal solar irradiance measurements. Because the MFRSR's receiver has a non-Lambertian response, for a correct interpretation of measured radiation an

  9. Results of the Second Diffuse Horizontal Irradiance IOP

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

    measurement that is multiplied by the cosine of the solar zenith angle to get the direct component normal to the plane of incidence. This is arguably the best calibration...

  10. Discrepancies in Shortwave Diffuse Measured and Modeled Irradiances...

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

    ... Corresponding Author Allison Payton, Allison@icess.ucsb.edu References Harrison, L., J. Michalsky, and J. Berndt, 1994: Automated multi-filter rotating shadow-band radiometer: An ...

  11. Cosmology with matter diffusion

    SciTech Connect (OSTI)

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field ? which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter ?. The standard ?CDM model can be recovered by setting ? = 0. If diffusion takes place (? > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  12. Nodal Diffusion & Transport Theory

    Energy Science and Technology Software Center (OSTI)

    1992-02-19

    DIF3D solves multigroup diffusion theory eigenvalue, adjoint, fixed source, and criticality (concentration, buckling, and dimension search) problems in 1, 2, and 3-space dimensions for orthogonal (rectangular or cylindrical), triangular, and hexagonal geometries. Anisotropic diffusion theory coefficients are permitted. Flux and power density maps by mesh cell and regionwise balance integrals are provided. Although primarily designed for fast reactor problems, upscattering and internal black boundary conditions are also treated.

  13. ARM: Portable Radiation Package: Broadband Radiometers (Dataset...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  14. ARM: Portable Radiation Package: Orientation Data (Dataset) ...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  15. ARM: Ameriflux Measurement Component (Dataset) | Data Explorer

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Shortwave broadband total downwelling irradiance; Shortwave ...

  16. ARM: Portable Radiation Package: Broadband Radiometers, 1 second...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  17. ARM: Portable Radiation Package: Orientation Data, 1 second resolution...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  18. ARM: Portable Radiation Package: Position and Heading Data (Dataset...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  19. ARM: Portable Radiation Package: Position and Heading Data with...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  20. ARM: Portable Radiation Package: Fast Rotating Shadowband Radiometer...

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband downwelling irradiance; Shortwave broadband ...

  1. Quantifying Aerosol Direct Effects from Broadband Irradiance and Spectral Aerosol Optical Depth Observations

    SciTech Connect (OSTI)

    Creekmore, Torreon N.; Joseph, Everette; Long, Charles N.; Li, Siwei

    2014-05-16

    We outline a methodology using broadband and spectral irradiances to quantify aerosol direct effects on the surface diffuse shortwave (SW) irradiance. Best Estimate Flux data span a 13 year timeframe at the Department of Energy Atmospheric Radiation Measurement Program’s Southern Great Plains (SGP) site. Screened clear-sky irradiances and aerosol optical depth (AOD), for solar zenith angles ≤ 65°, are used to estimate clear-sky diffuse irradiances. We validate against detected clear-sky observations from SGP’s Basic Radiation System (BRS). BRS diffuse irradiances were in accordance with estimates, producing a root-mean-square error and mean bias errors of 4.0 W/m2 and -1.4 W/m2, respectively. Absolute differences show 99% of estimates within ±10 W/m2 (10%) of the mean BRS observations. Clear-sky diffuse estimates are used to derive quantitative estimates of aerosol radiative effects, represented as the aerosol diffuse irradiance (ADI). ADI is the contribution of diffuse SW to global SW, attributable to scattering of atmospheric transmission by natural plus anthropogenic aerosols. Estimated slope for the ADI as a function of AOD indicates an increase of ~22 W/m2 in diffuse SW for every 0.1 increase in AOD. Such significant increases in the diffuse fraction could possibly increase photosynthesis. Annual mean ADI is 28.2 W/m2, and heavy aerosol loading at SGP provides up to a maximum increase of 120 W/m2 in diffuse SW over background conditions. With regard to seasonal variation, the mean diffuse forcings are 17.2, 33.3, 39.0, and 23.6 W/m2 for winter, spring, summer, and fall, respectively.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Phase-field simulations of gas density within bubbles under irradiation

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Phase-field simulations of gas density within bubbles under irradiation Citation Details In-Document Search Title: Phase-field simulations of gas density within bubbles under irradiation Phase-field simulations are used to study the evolution of gas density within irradiation-induced bubbles. In our simulations, the dpa rate, gas production rate, and defect diffusivities are systematically varied to understand their effect on bubble nucleation rates,

  7. Formation of long-range ordered quantum dots arrays in amorphous matrix by ion beam irradiation

    SciTech Connect (OSTI)

    Buljan, M.; Bogdanovic-Radovic, I.; Karlusic, M.; Desnica, U. V.; Radic, N.; Dubcek, P.; Drazic, G.; Salamon, K.; Bernstorff, S.; Holy, V.

    2009-08-10

    We demonstrate the production of a well ordered three-dimensional array of Ge quantum dots in amorphous silica matrix. The ordering is achieved by ion beam irradiation and annealing of a multilayer film. Structural analysis shows that quantum dots nucleate along the direction of the ion beam used for irradiation, while the mutual distance of the quantum dots is determined by the diffusion properties of the multilayer material rather than the distances between traces of ions that are used for irradiation.

  8. Phosphorus out-diffusion in laser molten silicon

    SciTech Connect (OSTI)

    Köhler, J. R.; Eisele, S. J.

    2015-04-14

    Laser doping via liquid phase diffusion enables the formation of defect free pn junctions and a tailoring of diffusion profiles by varying the laser pulse energy density and the overlap of laser pulses. We irradiate phosphorus diffused 100 oriented p-type float zone silicon wafers with a 5 μm wide line focused 6.5 ns pulsed frequency doubled Nd:YVO{sub 4} laser beam, using a pulse to pulse overlap of 40%. By varying the number of laser scans N{sub s} = 1, 2, 5, 10, 20, 40 at constant pulse energy density H = 1.3 J/cm{sup 2} and H = 0.79 J/cm{sup 2} we examine the out-diffusion of phosphorus atoms performing secondary ion mass spectroscopy concentration measurements. Phosphorus doping profiles are calculated by using a numerical simulation tool. The tool models laser induced melting and re-solidification of silicon as well as the out-diffusion of phosphorus atoms in liquid silicon during laser irradiation. We investigate the observed out-diffusion process by comparing simulations with experimental concentration measurements. The result is a pulse energy density independent phosphorus out-diffusion velocity v{sub out} = 9 ± 1 cm/s in liquid silicon, a partition coefficient of phosphorus 1 < k{sub p} < 1.1 and a diffusion coefficient D = 1.4(±0.2)cm{sup 2}/s × 10{sup −3 }× exp[−183 meV/(k{sub B}T)].

  9. Irradiation-induced composition patterns in binary solid solutions

    SciTech Connect (OSTI)

    Dubey, Santosh; El-Azab, Anter

    2013-09-28

    A theoretical/computational model for the irradiation-driven compositional instabilities in binary solid solutions has been developed. The model is suitable for investigating the behavior of structural alloys and metallic nuclear fuels in a reactor environment as well as the response of alloy thin films to ion beam irradiation. The model is based on a set of reaction-diffusion equations for the dynamics of vacancies, interstitials, and lattice atoms under irradiation. The dynamics of these species includes the stochastic generation of defects by collision cascades as well as the defect reactions and diffusion. The atomic fluxes in this model are derived based on the transitions of lattice defects. The set of reaction-diffusion equations are stiff, hence a stiffly stable method, also known as the Gear method, has been used to numerically approximate the equations. For the Cu-Au alloy in the solid solution regime, the model results demonstrate the formation of compositional patterns under high-temperature particle irradiation, with Fourier space properties (Fourier spectrum, average wavelength, and wavevector) depending on the cascade damage characteristics, average composition, and irradiation temperature.

  10. Apparatus for diffusion separation

    DOE Patents [OSTI]

    Nierenberg, William A.; Pontius, Rex B.

    1976-08-10

    1. The method of testing the separation efficiency of porous permeable membranes which comprises causing a stream of a gaseous mixture to flow into contact with one face of a finely porous permeable membrane under such conditions that a major fraction of the mixture diffuses through the membrane, maintaining a rectangular cross section of the gaseous stream so flowing past said membrane, continuously recirculating the gas that diffuses through said membrane and continuously withdrawing the gas that does not diffuse through said membrane and maintaining the volume of said recirculating gas constant by continuously introducing into said continuously recirculating gas stream a mass of gas equivalent to that which is continuously withdrawn from said gas stream and comparing the concentrations of the light component in the entering gas, the withdrawn gas and the recirculated gas in order to determine the efficiency of said membrane.

  11. Irradiation-induced nano-voids in strained tin precipitates in silicon

    SciTech Connect (OSTI)

    Gaiduk, P. I., E-mail: gaiduk@phys.au.dk [Department of Physics and Astronomy/iNANO, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C (Denmark); Department of Physical Electronics and Nanotechnology, Belarusian State University, prosp. Nezavisimosti, 4, 220030 Minsk (Belarus); Lundsgaard Hansen, J., E-mail: johnlh@phys.au.dk; Nylandsted Larsen, A., E-mail: anl@phys.au.dk [Department of Physics and Astronomy/iNANO, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus C (Denmark)

    2014-04-14

    We report on self-assembling of spherically shaped voids in nanometer size strained Sn precipitates after irradiation with He{sup +} ions in different conditions. It is found that high-temperature irradiation induces vacancies which are collected by compressively strained Sn precipitates enhancing of out-diffusion of Sn atoms from the precipitates. Nano-voids formation takes place simultaneously with a ?- to ?-phase transformation in the Sn precipitates. Post-irradiation thermal treatment leads to the removal of voids and a backward transformation of the Sn phase to ?-phase. Strain-enhanced separation of point defects along with vacancy assisted Sn out-diffusion and precipitate dissolution are discussed.

  12. schwartz(3)-98.pdf

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

    57 Correlated Short Term Fluctuations in Aerosol Optical Thickness and Shortwave Radiative Quantities S. E. Schwartz Environmental Chemistry Division Brookhaven National Laboratory Upton, New York Abstract Close examination of direct normal solar irradiance (DNSI) and downwelling diffuse irradiance (DDI) on cloud-free days at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) site reveals anticorrelated short- term (several minute) fluctuations, especially prominent in the

  13. Diffusion Bonding Characterization

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

    Diffusion Bonding Characterization - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary Power Energy Conversion Efficiency Solar Energy Wind Energy Water Power Supercritical CO2 Geothermal Natural Gas Safety, Security & Resilience of the Energy Infrastructure Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel Cycle Defense Waste Management

  14. 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)

  15. 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.

  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. 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. Enhanced structural stability of nanoporous zirconia under irradiation of He

    SciTech Connect (OSTI)

    Yang, Tengfei; Huang, Xuejun; Wang, Chenxu; Zhang, Yanwen; Xue, Jianming; Yan, Sha; Wang, Yuguang

    2012-01-01

    This work reports a greatly enhanced tolerance for He irradiation-induced swelling in nanocrystalline zirconia film with interconnected nanoporous structure (hereinafter referred as to NC-C). Compared to bulk yttria-stabilized zirconia (YSZ) and another nanocrystalline zirconia film only with discrete nano voids (hereinafter referred as to NC-V), the NC-C film reveals good tolerance for irradiation of high-fluence He. No appreciable surface blistering can be found even at the highest fluence of 6 1017 cm2 in NCC film. From TEM analysis of as-irradiated samples, the enhanced tolerance for volume swelling in NCC film is attributed to the enhanced diffusion mechanism of deposited He via widely distributed nano channels. Furthermore, the growth of grain size is quite small for both nanocrystalline zirconia films after irradiation, which is ascribed to the decreasing of area of grain boundary due to loose structure and low energy of primary knock-on atoms for He ions.

  19. Laser activated diffuse discharge switch (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Laser activated diffuse discharge switch Title: Laser activated diffuse discharge switch The invention is a gas mixture for a diffuse discharge switch which is capable of changing ...

  20. A method for estimating direct normal solar irradiation from satellite data for a tropical environment

    SciTech Connect (OSTI)

    Janjai, Serm

    2010-09-15

    In order to investigate a potential use of concentrating solar power technologies and select an optimum site for these technologies, it is necessary to obtain information on the geographical distribution of direct normal solar irradiation over an area of interest. In this work, we have developed a method for estimating direct normal irradiation from satellite data for a tropical environment. The method starts with the estimation of global irradiation on a horizontal surface from MTSAT-1R satellite data and other ground-based ancillary data. Then a satellite-based diffuse fraction model was developed and used to estimate the diffuse component of the satellite-derived global irradiation. Based on this estimated global and diffuse irradiation and the solar radiation incident angle, the direct normal irradiation was finally calculated. To evaluate its performance, the method was used to estimate the monthly average hourly direct normal irradiation at seven pyrheliometer stations in Thailand. It was found that values of monthly average hourly direct normal irradiation from the measurements and those estimated from the proposed method are in reasonable agreement, with a root mean square difference of 16% and a mean bias of -1.6%, with respect to mean measured values. After the validation, this method was used to estimate the monthly average hourly direct normal irradiation over Thailand by using MTSAT-1R satellite data for the period from June 2005 to December 2008. Results from the calculation were displayed as hourly and yearly irradiation maps. These maps reveal that the direct normal irradiation in Thailand was strongly affected by the tropical monsoons and local topography of the country. (author)

  1. Diffusion in silicon isotope heterostructures

    SciTech Connect (OSTI)

    Silvestri, Hughes Howland

    2004-05-14

    The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and {sup 28}Si enriched layers, enables the observation of {sup 30}Si self-diffusion from the natural layers into the {sup 28}Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion mechanisms, the native defect charge states, and the self- and dopant diffusion coefficients can be determined. This information is necessary to enhance the physical modeling of dopant diffusion in Si. It is of particular interest to the modeling of future electronic Si devices, where the nanometer-scale features have created the need for precise physical models of atomic diffusion in Si. The modeling of the experimental profiles of simultaneous diffusion of B and Si under p-type extrinsic conditions revealed that both species are mediated by neutral and singly, positively charged Si self-interstitials. The diffusion of As and Si under extrinsic n-type conditions yielded a model consisting of the interstitialcy and vacancy mechanisms of diffusion via singly negatively charged self-interstitials and neutral vacancies. The simultaneous diffusion of P and Si has been modeled on the basis of neutral and singly negatively charged self-interstitials and neutral and singly positively charged P species. Additionally, the temperature dependence of the diffusion coefficient of Si in Ge was measured over the temperature range of 550 C to 900 C using a buried Si layer in an epitaxially grown Ge layer.

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

    SciTech Connect (OSTI)

    Dang, Z. Y.; Breese, M. B. H.; Lin, Y.; Tok, E. S.; Vittone, E.

    2014-05-12

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

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

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

    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 decompositionmore » 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.« less

  4. Apparatus for diffusion separation

    DOE Patents [OSTI]

    Nierenberg, William A.

    1976-08-10

    1. A diffuser separator apparatus which comprises a plurality of flow channels in a single stage, each of said channels having an inlet port and an outlet port and a constant cross sectional area between said ports, at least a portion of the defining surface of each of said channels being a diffusion separation membrane, and each of said channels having a different cross sectional area, means for connecting said channels in series so that each successive channel of said series has a smaller cross sectional area than the previous channel of said series, a source of gaseous mixture, individual means for flowing said gaseous mixture to the inlet port of each of said channels, gas receiving and analyzing means, individual means for flowing gas passing from each of said outlet ports and means for flowing gas passing through said membranes to said receiving and analyzing means, and individual means for connecting the outlet port of each channel with the inlet port of the channel having the next smaller cross sectional area.

  5. Light diffusing fiber optic chamber (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: light; diffusing; fiber; optic; chamber; light; diffusion; transmitting; light; target; light; transmitted; ...

  6. Preliminary Analysis of ARM SGP Area Sky Cover and Downwelling...

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

    Clarifying and Implementing a Stricter DOD Definition Across Datastreams C. Sivaraman, B. Ermold, M. Macduff Pacific Northwest National Laboratory Definition of DOD: All dimension,...

  7. Light diffusing fiber optic chamber

    DOE Patents [OSTI]

    Maitland, Duncan J.

    2002-01-01

    A light diffusion system for transmitting light to a target area. The light is transmitted in a direction from a proximal end to a distal end by an optical fiber. A diffusing chamber is operatively connected to the optical fiber for transmitting the light from the proximal end to the distal end and transmitting said light to said target area. A plug is operatively connected to the diffusing chamber for increasing the light that is transmitted to the target area.

  8. Fuel Thermo-physical Characterization Project: Evaluation of Models to Calculate Thermal Diffusivity of Layered Composites

    SciTech Connect (OSTI)

    Burkes, Douglas; Casella, Amanda J.; Gardner, Levi D.; Casella, Andrew M.; Huber, Tanja K.; Breitkreutz, Harald

    2015-02-11

    The Office of Material Management and Minimization Fuel Thermo-physical Characterization Project at Pacific Northwest National Laboratory (PNNL) is tasked with using PNNL facilities and processes to receive irradiated low enriched uranium-molybdenum fuel plate samples and perform analyses in support of the Office of Material Management and Minimization Reactor Conversion Program. This work is in support of the Fuel Development Pillar that is managed by Idaho National Laboratory. A key portion of the scope associated with this project was to measure the thermal properties of fuel segments harvested from plates that were irradiated in the Advanced Test Reactor. Thermal diffusivity of samples prepared from the fuel segments was measured using laser flash analysis. Two models, one developed by PNNL and the other developed by the Technische Universität München (TUM), were evaluated to extract the thermal diffusivity of the uranium-molybdenum alloy from measurements made on the irradiated, layered composites. The experimental data of the “TC” irradiated fuel segment was evaluated using both models considering a three-layer and five-layer system. Both models are in acceptable agreement with one another and indicate that the zirconium diffusion barrier has a minimal impact on the overall thermal diffusivity of the monolithic U-Mo fuel.

  9. 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.

  10. 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.

  11. Fractional diffusion on bounded domains

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

    Defterli, Ozlem; D'Elia, Marta; Du, Qiang; Gunzburger, Max Donald; Lehoucq, Richard B.; Meerschaert, Mark M.

    2015-03-13

    We found that the mathematically correct specification of a fractional differential equation on a bounded domain requires specification of appropriate boundary conditions, or their fractional analogue. In this paper we discuss the application of nonlocal diffusion theory to specify well-posed fractional diffusion equations on bounded domains.

  12. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

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

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-03

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying withmore » transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.« less

  13. Non-Contact Measurement of Thermal Diffusivity in Ion-Implanted Nuclear Materials

    SciTech Connect (OSTI)

    Hofmann, F.; Mason, D. R.; Eliason, J. K.; Maznev, A. A.; Nelson, K. A.; Dudarev, S. L.

    2015-11-03

    Knowledge of mechanical and physical property evolution due to irradiation damage is essential for the development of future fission and fusion reactors. Ion-irradiation provides an excellent proxy for studying irradiation damage, allowing high damage doses without sample activation. Limited ion-penetration-depth means that only few-micron-thick damaged layers are produced. Substantial effort has been devoted to probing the mechanical properties of these thin implanted layers. Yet, whilst key to reactor design, their thermal transport properties remain largely unexplored due to a lack of suitable measurement techniques. Here we demonstrate non-contact thermal diffusivity measurements in ion-implanted tungsten for nuclear fusion armour. Alloying with transmutation elements and the interaction of retained gas with implantation-induced defects both lead to dramatic reductions in thermal diffusivity. These changes are well captured by our modelling approaches. Our observations have important implications for the design of future fusion power plants.

  14. Enthalpy Diffusion in Multicomponent Flows

    SciTech Connect (OSTI)

    Cook, A W

    2008-11-12

    The enthalpy diffusion flux in the multicomponent energy equation is a well known yet frequently neglected term. It accounts for energy changes, associated with compositional changes, resulting from species diffusion. Enthalpy diffusion is important in flows where significant mixing occurs between species of dissimilar molecular weight. The term plays a critical role in preventing local violations of the entropy condition. In simulations of nonpremixed combustion, omission of the enthalpy flux can lead to anomalous temperature gradients, which may cause mixing regions to exceed ignition conditions. The term can also play a role in generating acoustic noise in turbulent mixing layers. Euler solvers that rely on numerical diffusion to mix fluids cannot accurately predict the temperature in mixed regions. On the other hand, Navier-Stokes solvers that incorporate enthalpy diffusion can provide much more accurate results.

  15. Portable vapor diffusion coefficient meter

    DOE Patents [OSTI]

    Ho, Clifford K.

    2007-06-12

    An apparatus for measuring the effective vapor diffusion coefficient of a test vapor diffusing through a sample of porous media contained within a test chamber. A chemical sensor measures the time-varying concentration of vapor that has diffused a known distance through the porous media. A data processor contained within the apparatus compares the measured sensor data with analytical predictions of the response curve based on the transient diffusion equation using Fick's Law, iterating on the choice of an effective vapor diffusion coefficient until the difference between the predicted and measured curves is minimized. Optionally, a purge fluid can forced through the porous media, permitting the apparatus to also measure a gas-phase permeability. The apparatus can be made lightweight, self-powered, and portable for use in the field.

  16. 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.

  17. Irradiation response in weldment and HIP joint of reduced activation ferritic/martensitic steel, F82H

    SciTech Connect (OSTI)

    Hirose, Takanori [Japan Atomic Energy Agency (JAEA); Sokolov, Mikhail A [ORNL; Ando, M. [Japan Atomic Energy Agency (JAEA); Tanigawa, H. [Japan Atomic Energy Agency (JAEA); Shiba, K. [Japan Atomic Energy Agency (JAEA); Stoller, Roger E [ORNL; Odette, G.R. [University of California, Santa Barbara

    2013-11-01

    This work investigates irradiation response in the joints of F82H employed for a fusion breeding blanket. The joints, which were prepared using welding and diffusion welding, were irradiated up to 6 dpa in the High Flux Isotope Reactor at the Oak Ridge National Laboratory. Post-irradiation tests revealed hardening in weldment (WM) and base metal (BM) greater than 300 MPa. However, the heat affected zones (HAZ) exhibit about half that of WM and BM. Therefore, neutron irradiation decreased the strength of the HAZ, leaving it in danger of local deformation in this region. Further the hardening in WM made with an electron beam was larger than that in WM made with tungsten inert gas welding. However the mechanical properties of the diffusion-welded joint were very similar to those of BM even after the irradiation.

  18. Irradiation-induced grain growth in nanocrystalline reduced activation ferrite/martensite steel

    SciTech Connect (OSTI)

    Liu, W. B.; Chen, L. Q. [Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zhang, C., E-mail: chizhang@tsinghua.edu.cn; Yang, Z. G. [Key Laboratory of Advanced Materials of Ministry of Education, School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Ji, Y. Z. [Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zang, H. [Department of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049 (China); Shen, T. L. [Institute of Modern Physics, Chinese Academy of Science, Lanzhou 730000 (China)

    2014-09-22

    In this work, we investigate the microstructure evolution of surface-nanocrystallized reduced activation ferrite/martensite steels upon high-dose helium ion irradiation (24.3 dpa). We report a significant irradiation-induced grain growth in the irradiated buried layer at a depth of 300500?nm, rather than at the peak damage region (at a depth of ?840?nm). This phenomenon can be explained by the thermal spike model: minimization of the grain boundary (GB) curvature resulting from atomic diffusion in the cascade center near GBs.

  19. Improved diffuser for augmenting a wind turbine

    DOE Patents [OSTI]

    Foreman, K.M.; Gilbert, B.L.

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  20. Diffuser for augmenting a wind turbine

    DOE Patents [OSTI]

    Foreman, Kenneth M.; Gilbert, Barry L.

    1984-01-01

    A diffuser for augmenting a wind turbine having means for energizing the boundary layer at several locations along the diffuser walls is improved by the addition of a short collar extending radially outward from the outlet of the diffuser.

  1. Luminescent Concentration of Diffuse Light

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

    Luminescent Concentration of Diffuse Light Achieving 30X Concentration Work w as p erformed a t L BL a nd U IUC Bronstein, N .D.; Y ao, Y .; X u, L .; O 'Brien, E .; P owers, A...

  2. 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)

  3. Ag Out-surface Diffusion In Crystalline SiC With An Effective SiO2 Diffusion Barrier

    SciTech Connect (OSTI)

    Xue, H.; Xiao, Haiyan Y.; Zhu, Zihua; Shutthanandan, V.; Snead, Lance L.; Boatner, Lynn A.; Weber, William J.; Zhang, Y.

    2015-09-01

    For applications of tristructural isotropic (TRISO) fuel particles in high temperature reactors, release of radioactive Ag isotope (110mAg) through the SiC coating layer is a safety concern. To understand the diffusion mechanism, Ag ion implantations near the surface and in the bulk were performed by utilizing different ion energies and energy-degrader foils. High temperature annealing was carried out on the as-irradiated samples to study the possible out-surface diffusion. Before and after annealing, Rutherford backscattering spectrometry (RBS) and secondary ion mass spectrometry (SIMS) measurements were employed to obtain the elemental profiles of the implanted samples. The results suggest little migration of buried Ag in the bulk, and an out-diffusion of the implanted Ag in the near-surface region of single crystal SiC. It is also found that a SiO2 layer, which was formed during annealing, may serve as an effective barrier to reduce or prevent Ag out diffusion through the SiC coating layer.

  4. Boron diffusion in silicon devices

    SciTech Connect (OSTI)

    Rohatgi, Ajeet; Kim, Dong Seop; Nakayashiki, Kenta; Rounsaville, Brian

    2010-09-07

    Disclosed are various embodiments that include a process, an arrangement, and an apparatus for boron diffusion in a wafer. In one representative embodiment, a process is provided in which a boric oxide solution is applied to a surface of the wafer. Thereafter, the wafer is subjected to a fast heat ramp-up associated with a first heating cycle that results in a release of an amount of boron for diffusion into the wafer.

  5. Multiscale simulation of xenon diffusion and grain boundary segregation in UO₂

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

    Andersson, David A.; Tonks, Michael R.; Casillas, Luis; Vyas, Shyam; Nerikar, Pankaj; Uberuaga, Blas P.; Stanek, Christopher R.

    2015-07-01

    In light water reactor fuel, gaseous fission products segregate to grain boundaries, resulting in the nucleation and growth of large intergranular fission gas bubbles. The segregation rate is controlled by diffusion of fission gas atoms through the grains and interaction with the boundaries. Based on the mechanisms established from earlier density functional theory (DFT) and empirical potential calculations, diffusion models for xenon (Xe), uranium (U) vacancies and U interstitials in UO₂ have been derived for both intrinsic (no irradiation) and irradiation conditions. Segregation of Xe to grain boundaries is described by combining the bulk diffusion model with a model formore » the interaction between Xe atoms and three different grain boundaries in UO₂ (Σ5 tilt, Σ5 twist and a high angle random boundary), as derived from atomistic calculations. The present model does not attempt to capture nucleation or growth of fission gas bubbles at the grain boundaries. The point defect and Xe diffusion and segregation models are implemented in the MARMOT phase field code, which is used to calculate effective Xe and U diffusivities as well as to simulate Xe redistribution for a few simple microstructures.« less

  6. Diffusive mixing and Tsallis entropy

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

    O'Malley, Daniel; Vesselinov, Velimir V.; Cushman, John H.

    2015-04-29

    Brownian motion, the classical diffusive process, maximizes the Boltzmann-Gibbs entropy. The Tsallis q-entropy, which is non-additive, was developed as an alternative to the classical entropy for systems which are non-ergodic. A generalization of Brownian motion is provided that maximizes the Tsallis entropy rather than the Boltzmann-Gibbs entropy. This process is driven by a Brownian measure with a random diffusion coefficient. In addition, the distribution of this coefficient is derived as a function of q for 1 < q < 3. Applications to transport in porous media are considered.

  7. Response of nanostructured ferritic alloys to high-dose heavy ion irradiation

    SciTech Connect (OSTI)

    Parish, Chad M.; White, Ryan M.; LeBeau, James M.; Miller, Michael K.

    2014-02-01

    A latest-generation aberration-corrected scanning/transmission electron microscope (STEM) is used to study heavy-ion-irradiated nanostructured ferritic alloys (NFAs). Results are presented for STEM X-ray mapping of NFA 14YWT irradiated with 10 MeV Pt to 16 or 160 dpa at -100°C and 750°C, as well as pre-irradiation reference material. Irradiation at -100°C results in ballistic destruction of the beneficial microstructural features present in the pre-irradiated reference material, such as Ti-Y-O nanoclusters (NCs) and grain boundary (GB) segregation. Irradiation at 750°C retains these beneficial features, but indicates some coarsening of the NCs, diffusion of Al to the NCs, and a reduction of the Cr-W GB segregation (or solute excess) content. Ion irradiation combined with the latest-generation STEM hardware allows for rapid screening of fusion candidate materials and improved understanding of irradiation-induced microstructural changes in NFAs.

  8. Derivation of effective fission gas diffusivities in UO2 from lower length scale simulations and implementation of fission gas diffusion models in BISON

    SciTech Connect (OSTI)

    Andersson, Anders David Ragnar; Pastore, Giovanni; Liu, Xiang-Yang; Perriot, Romain Thibault; Tonks, Michael; Stanek, Christopher Richard

    2014-11-07

    This report summarizes the development of new fission gas diffusion models from lower length scale simulations and assessment of these models in terms of annealing experiments and fission gas release simulations using the BISON fuel performance code. Based on the mechanisms established from density functional theory (DFT) and empirical potential calculations, continuum models for diffusion of xenon (Xe) in UO2 were derived for both intrinsic conditions and under irradiation. The importance of the large XeU3O cluster (a Xe atom in a uranium + oxygen vacancy trap site with two bound uranium vacancies) is emphasized, which is a consequence of its high mobility and stability. These models were implemented in the MARMOT phase field code, which is used to calculate effective Xe diffusivities for various irradiation conditions. The effective diffusivities were used in BISON to calculate fission gas release for a number of test cases. The results are assessed against experimental data and future directions for research are outlined based on the conclusions.

  9. Diffusion In Confinement: Kinetic Simulations of Self- andCollective...

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

    Diffusion In Confinement: Kinetic Simulations of Self- and Collective-Diffusion Behavior of Adsorbed Gases...

  10. Irradiated Microsphere Gamma Analyzer for Examination of Particle Fuel

    SciTech Connect (OSTI)

    Paul A. Demkowicz; Various

    2014-06-01

    Fabrication of the first series of fuel compacts for the current US tristructural isotropic (TRISO) coated particle fuel development and qualification effort was completed at Oak Ridge National Laboratory (ORNL) in 2006. In November of 2009, after almost 3 years and 620 effective full power days of irradiation in the Advanced Test Reactor at Idaho National Laboratory (INL), the first Advanced Gas Reactor irradiation test (AGR-1) was concluded. Compacts were irradiated at a calculated timeaveraged, volume-averaged temperature of 9551136C to a burnup ranging from 11.219.5% fissions per initial metal atom and a total fast fluence of 2.24.31025 n/m2 [1]. No indication of fission product release from TRISO coating failure was observed during the irradiation test, based on real-time monitoring of gaseous fission products. Post-irradiation examination (PIE) and hightemperature safety testing of the compacts has been in progress at both ORNL and INL since 2010, and have revealed small releases of a limited subset of fission products (such as silver, cesium, and europium). Past experience has shown that some elements can be released from TRISO particles when a defect forms in the SiC layer, even when one or more pyrocarbon layers remain intact and retain the gaseous fission products. Some volatile elements can also be released by diffusion through an intact SiC layer during safety testing if temperatures are high enough and the duration is long enough. In order to understand and quantify the release of certain radioactive fission products, it is sometimes necessary to individually examine each of the more than 4000 coated particles in a given compact. The Advanced Irradiated Microsphere Gamma Analyzer (Advanced- IMGA) was designed to perform this task in a remote hot cell environment. This paper describes the Advanced- IMGA equipment and examination process and gives results for a typical full compact evaluation.

  11. Optimal measurement of surface shortwave irradiance using current instrumentation -- the ARM experience

    SciTech Connect (OSTI)

    Michalsky, J.; Rubes, M.; Stoffel, T.; Wesley, M.; Splitt, M.; DeLuisi, J.

    1997-03-01

    Shortwave (solar) measurements of surface irradiance for clear sky conditions disagree with a number of different models. Betts used the European Center for Medium-range Forecasts (ECMWF) shortwave model to calculate surface irradiance that were 5-10 percent higher than measurements. Wild used a different formulation of the ECMWF shortwave model, but found that the model overpredicted clear-sky shortwave and average of 3 percent. Ding and Wang used data from the Atmospheric Radiation Measurement (ARM) program and found that the GENESIS GCM shortwave model, likewise, overpredicted clear-sky irradiance by about 4 percent. To help resolve the measurement dilemma, reference instruments were deployed in April 1996 at the Southern Great Plains ARM site central facility very near the shortwave measurements. The rest of the paper describes the experiment undertaken to ascertain total horizontal shortwave irradiance at the surface, including a separation of the direct normal and diffuse horizontal components. Results and a discussion of same concludes the paper.

  12. ARM - Datastreams - prpfrsr

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

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

  13. PowerPoint Presentation

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

    to find visible c ; lots of computation total broadband downwelling irradiance Simple empirical method (look right) Simple empirical method: From Barnard and Long...

  14. Microsoft PowerPoint - SurfSpecAlb_cnl4.ppt

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

    on whether the ratio of best estimate direct to best estimate total downwelling irradiance is above or below 15% * Missing albedos estimated using either the albedo noon value...

  15. Pipe diffusion at dislocations in UO2

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

    of pipe diffusion to the overall O 2 and U 4+ diffusion is also discussed. 2014 Elsevier B.V. All rights reserved. 1. Introduction During its lifetime in-pile nuclear fuel...

  16. Method for Analyzing Passive SiC Thermometry with a Continuous Dilatometer to Determine Irradiation Temperature

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

    Campbell, Anne A; Porter, Wallace D; Katoh, Yutai; Snead, Lance Lewis

    2016-01-01

    Silicon carbide is used as a passive post-irradiation temperature monitor because the irradiation defects will anneal out above the irradiation temperature. The irradiation temperature is determined by measuring a property change after isochronal annealing, i.e., lattice spacing, dimensions, electrical resistivity, thermal diffusivity, or bulk density. However, such methods are time-consuming since the steps involved must be performed in a serial manner. This work presents the use of thermal expansion from continuous dilatometry to calculate the SiC irradiation temperature, which is an automated process requiring minimal setup time. Analysis software was written that performs the calculations to obtain the irradiation temperaturemoreand removes possible user-introduced error while standardizing the analysis. This method has been compared to an electrical resistivity and isochronal annealing investigation, and the results revealed agreement of the calculated temperatures. These results show that dilatometry is a reliable and less time-intensive process for determining irradiation temperature from passive SiC thermometry.less

  17. Method for analyzing passive silicon carbide thermometry with a continuous dilatometer to determine irradiation temperature

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

    Campbell, Anne A.; Porter, Wallace D.; Katoh, Yutai; Snead, Lance Lewis

    2016-01-14

    Silicon carbide is used as a passive post-irradiation temperature monitor because the irradiation defects will anneal out above the irradiation temperature. The irradiation temperature is determined by measuring a property change after isochronal annealing, i.e., lattice spacing, dimensions, electrical resistivity, thermal diffusivity, or bulk density. However, such methods are time-consuming since the steps involved must be performed in a serial manner. This work presents the use of thermal expansion from continuous dilatometry to calculate the SiC irradiation temperature, which is an automated process requiring minimal setup time. Analysis software was written that performs the calculations to obtain the irradiation temperaturemore » and removes possible user-introduced error while standardizing the analysis. In addition, this method has been compared to an electrical resistivity and isochronal annealing investigation, and the results revealed agreement of the calculated temperatures. These results show that dilatometry is a reliable and less time-intensive process for determining irradiation temperature from passive SiC thermometry.« less

  18. Microstructure and Cs Behavior of Ba-Doped Aluminosilicate Pollucite Irradiated with F+ Ions

    SciTech Connect (OSTI)

    Jiang, Weilin; Kovarik, Libor; Zhu, Zihua; Varga, Tamas; Engelhard, Mark H.; Bowden, Mark E.; Nenoff, Tina M.; Garino, Terry

    2014-08-07

    Radionuclide 137Cs is one of the major fission products that dominate heat generation in spent fuels over the first 300 hundred years. A durable waste form for 137Cs that decays to 137Ba is needed to minimize its environmental impact. Aluminosilicate pollucite CsAlSi2O6 is selected as a model waste form to study the decay-induced structural effects. While Ba-containing precipitates are not present in charge-balanced Cs0.9Ba0.05AlSi2O6, they are found in Cs0.9Ba0.1AlSi2O6 and identified as monoclinic Ba2Si3O8. Pollucite is susceptible to electron irradiation induced amorphization. The threshold density of the electronic energy deposition for amorphization is determined to be ~235 keV/nm3. Pollucite can be readily amorphized under F+ ion irradiation at 673 K. A significant amount of Cs diffusion and release from the amorphized pollucite is observed during the irradiation. However, cesium is immobile in the crystalline structure under He+ ion irradiation at room temperature. The critical temperature for amorphization is not higher than 873 K under F+ ion irradiation. If kept at or above 873 K all the time, the pollucite structure is unlikely to be amorphized; Cs diffusion and release are improbable. A general discussion regarding pollucite as a potential waste form is provided in this report.

  19. Effects of Irradiation on the Microstructure of U-7Mo Dispersion Fuel with Al-2Si Matrix

    SciTech Connect (OSTI)

    Dennis D. Keiser, Jr.; Jan-Fong Jue; Adam B. Robinson; Pavel Medvedev; Jian Gan; Brandon D. Miller; Daniel M. Wachs; Glenn A. Moore; Curtis R. Clark; Mitchell K. Meyer; M. Ross Finlay

    2012-06-01

    The Reduced Enrichment for Research and Test Reactor program is developing low-enriched uranium U-Mo dispersion fuels for application in research and test reactors around the world. As part of this development, fuel plates have been irradiated in the Advanced Test Reactor and then characterized using optical metallography (OM) and scanning electron microscopy (SEM) to determine the as-irradiated microstructure. To demonstrate the irradiation performance of U-7Mo dispersion fuel plates with 2 wt% Si added to the matrix, fuel plates were tested to medium burnups at intermediate fission rates as part of the RERTR-6 experiment. Further testing was performed to higher fission rates as part of the RERTR-7A experiment, and very aggressive testing (high temperature, high fission density, high fission rate) was performed in the RERTR-9A, RERTR-9B and AFIP-1 experiments. As-irradiated microstructures were compared to those observed after fabrication to determine the effects of irradiation on the microstructure. Based on comparison of the microstructural characterization results for each irradiated sample, some general conclusions can be drawn about how the microstructure evolves during irradiation: there is growth of the fuel/matrix interaction layer (FMI), which was present in the samples to some degree after fabrication, during irradiation; Si diffuses from the FMI layer to deeper depths in the U-7Mo particles as the irradiation conditions are made more aggressive; lowering of the Si content in the FMI layer results in an increase in the size of the fission gas bubbles; as the FMI layer grows during irradiation more Si diffuses from the matrix to the FMI layer/matrix interface, and interlinking of fission gas bubbles in the fuel plate microstructure that may indicate breakaway swelling is not observed.

  20. Analysis of clear hour solar irradiation for seven Canadian stations

    SciTech Connect (OSTI)

    Garrison, J.; Sahami, K.

    1995-12-31

    Hourly global and diffuse irradiation and corresponding surface meteorological data have been analyzed for the seven Canadian stations at Edmonton, Goose Bay, Montreal, Port Hardy, Resolute, Toronto, and Winnipeg. The variation of the most probable clear hour values of clearness index k{sub t}, diffuse index k{sub d}, direct beam index k{sub b}, and Angstrom turbidity coefficient {beta} with solar elevation, atmospheric precipitable water, and snow depth are obtained. Values of these quantities are presented which are consistent with the attenuation and scattering of solar radiation by the atmosphere which is expected. The most probable values of {beta} tend to be lower than the average values of {beta} recently reported by Gueymard. The data indicate a drift in the calibration of the instruments used for measurements of the irradiation data for the stations at Goose Bay and Resolute. The data for the other five stations indicate that the instrument calibration is maintained over the years of the data. 4 refs., 8 figs., 5 tabs.

  1. MODEL OF DIFFUSERS / PERMEATORS FOR HYDROGEN PROCESSING

    SciTech Connect (OSTI)

    Hang, T; William Jacobs, W

    2007-08-27

    Palladium-silver (Pd-Ag) diffusers are mainstays of hydrogen processing. Diffusers separate hydrogen from inert species such as nitrogen, argon or helium. The tubing becomes permeable to hydrogen when heated to more than 250 C and a differential pressure is created across the membrane. The hydrogen diffuses better at higher temperatures. Experimental or experiential results have been the basis for determining or predicting a diffuser's performance. However, the process can be mathematically modeled, and comparison to experimental or other operating data can be utilized to improve the fit of the model. A reliable model-based diffuser system design is the goal which will have impacts on tritium and hydrogen processing. A computer model has been developed to solve the differential equations for diffusion given the operating boundary conditions. The model was compared to operating data for a low pressure diffuser system. The modeling approach and the results are presented in this paper.

  2. Bulk and surface controlled diffusion of fission gas atoms

    SciTech Connect (OSTI)

    Andersson, Anders D.

    2012-08-09

    Fission gas retention and release impact nuclear fuel performance by, e.g., causing fuel swelling leading to mechanical interaction with the clad, increasing the plenum pressure and reducing the gap thermal conductivity. All of these processes are important to understand in order to optimize operating conditions of nuclear reactors and to simulate accident scenarios. Most fission gases have low solubility in the fuel matrix, which is especially pronounced for large fission gas atoms such as Xe and Kr, and as a result there is a significant driving force for segregation of gas atoms to extended defects such as grain boundaries or dislocations and subsequently for nucleation of gas bubbles at these sinks. Several empirical or semi-empirical models have been developed for fission gas release in nuclear fuels, e.g. [1-6]. One of the most commonly used models in fuel performance codes was published by Massih and Forsberg [3,4,6]. This model is similar to the early Booth model [1] in that it applies an equivalent sphere to separate bulk UO{sub 2} from grain boundaries represented by the sphere circumference. Compared to the Booth model, it also captures trapping at grain boundaries, fission gas resolution and it describes release from the boundary by applying timedependent boundary conditions to the circumference. In this work we focus on the step where fission gas atoms diffuse from the grain interior to the grain boundaries. The original Massih-Forsberg model describes this process by applying an effective diffusivity divided into three temperature regimes. In this report we present results from density functional theory calculations (DFT) that are relevant for the high (D{sub 3}) and intermediate (D{sub 2}) temperature diffusivities of fission gases. The results are validated by making a quantitative comparison to Turnbull's [8-10] and Matzke's data [12]. For the intrinsic or high temperature regime we report activation energies for both Xe and Kr diffusion in UO{sub 2{+-}x}, which compare favorably to available experiments. This is an extension of previous work [13]. In particular, it applies improved chemistry models for the UO{sub 2{+-}x} nonstoichiometry and its impact on the fission gas activation energies. The derivation of these models follows the approach that used in our recent study of uranium vacancy diffusion in UO{sub 2} [14]. Also, based on the calculated DFT data we analyze vacancy enhanced diffusion mechanisms in the intermediate temperature regime. In addition to vacancy enhanced diffusion we investigate species transport on the (111) UO{sub 2} surface. This is motivated by the formation of small voids partially filled with fission gas atoms (bubbles) in UO{sub 2} under irradiation, for which surface diffusion could be the rate-limiting transport step. Diffusion of such bubbles constitutes an alternative mechanism for mass transport in these materials.

  3. Laser activated diffuse discharge switch

    DOE Patents [OSTI]

    Christophorou, Loucas G. (Oak Ridge, TN); Hunter, Scott R. (Oak Ridge, TN)

    1988-01-01

    The invention is a gas mixture for a diffuse discharge switch which is capable of changing from a conducting state to an insulating state in the presence of electrons upon the introduction of laser light. The mixture is composed of a buffer gas such as nitrogen or argon and an electron attaching gas such as C.sub.6 H.sub.5 SH, C.sub.6 H.sub.5 SCH.sub.3, CH.sub.3 CHO and CF.sub.3 CHO wherein the electron attachment is brought on by indirect excitation of molecules to long-lived states by exposure to laser light.

  4. Solute redistribution and phase stability at FeCr/TiO2–x interfaces under ion irradiation

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

    Xu, Y.; Aguiar, J. A.; Yadav, S. K.; Anderoglu, O.; Baldwin, J. K.; Wang, Y. Q.; Valdez, James A.; Misra, A.; Luo, H. M.; Uberuaga, B. P.; et al

    2015-02-26

    Cr diffusion in trilayer thin films of 100 nm Fe–18Cr/125 nm TiO2–x/100 nm Fe–18Cr deposited on MgO substrates at 500 °C was studied by either annealing at 500 °C or Ni3+ ion irradiation at 500 °C. Microchemistry and microstructure evolution at the metal/oxide interfaces were investigated using (high-resolution) transmission electron microscopy, energy-dispersive X-ray spectroscopy and electron energy loss spectroscopy. Diffusion of Cr into the O-deficient TiO2 layer, with negligible segregation to the FeCr/TiO2–x interface itself, was observed under both annealing and irradiation. Cr diffusion into TiO2–x was enhanced in ion-irradiated samples as compared to annealed. Irradiation-induced voids and amorphization ofmore » TiO2–x was also observed. The experimental results are rationalized using first-principles calculations that suggest an energetic preference for substituting Ti with Cr in sub-stoichiometric TiO2. Furthermore, the implications of these results on the irradiation stability of oxide-dispersed ferritic alloys are discussed.« less

  5. ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Hodges, Gary

    The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.

  6. ARM Multi-Filter Rotating Shadowband Radiometer (MFRSR): irradiances

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Hodges, Gary

    1993-07-04

    The multifilter rotating shadowband radiometer (MFRSR) takes spectral measurements of direct normal, diffuse horizontal and total horizontal solar irradiances. These measurements are at nominal wavelengths of 415, 500, 615, 673, 870, and 940 nm. The measurements are made at a user-specified time interval, usually about one minute or less. The sampling rate for the Atmospheric Radiation Measurement (ARM) Climate Research Facility MFRSRs is 20 seconds. From such measurements, one may infer the atmosphere's optical depth at the wavelengths mentioned above. In turn, these optical depths may be used to derive information about the column abundances of ozone and water vapor (Michalsky et al. 1995), as well as aerosol (Michalsky et al. 1994) and other atmospheric constituents. A silicon detector is also part of the MFRSR. This detector provides a measure of the broadband direct normal, diffuse horizontal and total horizontal solar irradiances. A MFRSR head that is mounted to look vertically downward can measure upwelling spectral irradiances. In the ARM system, this instrument is called a multifilter radiometer (MFR). At the Southern Great Plains (SGP) there are two MFRs; one mounted at the 10-m height and the other at 25 m. At the North Slope of Alaska (NSA) sites, the MFRs are mounted at 10 m. MFRSR heads are also used to measure normal incidence radiation by mounting on a solar tracking device. These are referred to as normal incidence multi-filter radiometers (NIMFRs) and are located at the SGP and NSA sites. Another specialized use for the MFRSR is the narrow field of view (NFOV) instrument located at SGP. The NFOV is a ground-based radiometer (MFRSR head) that looks straight up.

  7. An asixymmetric diffusion experiment for the determination of diffusion and sorption coefficients of rock samples

    SciTech Connect (OSTI)

    Takeda, M.; Hiratsuka, T.; Ito, K.; Finsterle, S.

    2011-02-01

    Diffusion anisotropy is a critical property in predicting migration of substances in sedimentary formations with very low permeability. The diffusion anisotropy of sedimentary rocks has been evaluated mainly from laboratory diffusion experiments, in which the directional diffusivities are separately estimated by through-diffusion experiments using different rock samples, or concurrently by in-diffusion experiments in which only the tracer profile in a rock block is measured. To estimate the diffusion anisotropy from a single rock sample, this study proposes an axisymmetric diffusion test, in which tracer diffuses between a cylindrical rock sample and a surrounding solution reservoir. The tracer diffusion between the sample and reservoir can be monitored from the reservoir tracer concentrations, and the tracer profile could also be obtained after dismantling the sample. Semi-analytical solutions are derived for tracer concentrations in both the reservoir and sample, accounting for an anisotropic diffusion tensor of rank two as well as the dilution effects from sampling and replacement of reservoir solution. The transient and steady-state analyses were examined experimentally and numerically for different experimental configurations, but without the need for tracer profiling. These experimental configurations are tested for in- and out-diffusion experiments using Koetoi and Wakkanai mudstones and Shirahama sandstone, and are scrutinized by a numerical approach to identify favorable conditions for parameter estimation. The analysis reveals the difficulty in estimating diffusion anisotropy; test configurations are proposed for enhanced identifiability of diffusion anisotropy. Moreover, it is demonstrated that the axisymmetric diffusion test is efficient in obtaining the sorption parameter from both steady-state and transient data, and in determining the effective diffusion coefficient if isotropic diffusion is assumed. Moreover, measuring reservoir concentrations in an axisymmetric diffusion experiment coupled with tracer profiling may be a promising approach to estimate of diffusion anisotropy of sedimentary rocks.

  8. IRRADIATION PERFORMANCE OF U-Mo MONOLITHIC FUEL

    SciTech Connect (OSTI)

    M.K. Meyer; J. Gan; J.-F. Jue; D.D. Keiser; E. Perez; A. Robinson; D.M. Wachs; N. Woolstenhulme; G.L. Hofman; Y.-S. Kim

    2014-04-01

    High-performance research reactors require fuel that operates at high specific power to high fission density, but at relatively low temperatures. Research reactor fuels are designed for efficient heat rejection, and are composed of assemblies of thin-plates clad in aluminum alloy. The development of low-enriched fuels to replace high-enriched fuels for these reactors requires a substantially increased uranium density in the fuel to offset the decrease in enrichment. Very few fuel phases have been identified that have the required combination of very-high uranium density and stable fuel behavior at high burnup. UMo alloys represent the best known tradeoff in these properties. Testing of aluminum matrix U-Mo aluminum matrix dispersion fuel revealed a pattern of breakaway swelling behavior at intermediate burnup, related to the formation of a molybdenum stabilized high aluminum intermetallic phase that forms during irradiation. In the case of monolithic fuel, this issue was addressed by eliminating, as much as possible, the interfacial area between U-Mo and aluminum. Based on scoping irradiation test data, a fuel plate system composed of solid U-10Mo fuel meat, a zirconium diffusion barrier, and Al6061 cladding was selected for development. Developmental testing of this fuel system indicates that it meets core criteria for fuel qualification, including stable and predictable swelling behavior, mechanical integrity to high burnup, and geometric stability. In addition, the fuel exhibits robust behavior during power-cooling mismatch events under irradiation at high power.

  9. Crystal defect studies using x-ray diffuse scattering

    SciTech Connect (OSTI)

    Larson, B.C.

    1980-01-01

    Microscopic lattice defects such as point (single atom) defects, dislocation loops, and solute precipitates are characterized by local electronic density changes at the defect sites and by distortions of the lattice structure surrounding the defects. The effect of these interruptions of the crystal lattice on the scattering of x-rays is considered in this paper, and examples are presented of the use of the diffuse scattering to study the defects. X-ray studies of self-interstitials in electron irradiated aluminum and copper are discussed in terms of the identification of the interstitial configuration. Methods for detecting the onset of point defect aggregation into dislocation loops are considered and new techniques for the determination of separate size distributions for vacancy loops and interstitial loops are presented. Direct comparisons of dislocation loop measurements by x-rays with existing electron microscopy studies of dislocation loops indicate agreement for larger size loops, but x-ray measurements report higher concentrations in the smaller loop range. Methods for distinguishing between loops and three-dimensional precipitates are discussed and possibilities for detailed studies considered. A comparison of dislocation loop size distributions obtained from integral diffuse scattering measurements with those from TEM show a discrepancy in the smaller sizes similar to that described above.

  10. DOE Releases Request for Information for Paducah Gaseous Diffusion...

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

    Information for Paducah Gaseous Diffusion Plant Deactivation & Remediation Services DOE Releases Request for Information for Paducah Gaseous Diffusion Plant Deactivation &...

  11. Diffusion releases through one and two finite planar zones from...

    Office of Scientific and Technical Information (OSTI)

    WASTES; UNDERGROUND DISPOSAL; TUFF; DIFFUSION BARRIERS; GROUND WATER; RADIONUCLIDE MIGRATION; CONTAINERS; DIFFUSION; NUMERICAL ANALYSIS; CONCENTRATION RATIO; Yucca Mountain ...

  12. Diffusion releases through one and two finite planar zones from...

    Office of Scientific and Technical Information (OSTI)

    ... WASTES; UNDERGROUND DISPOSAL; TUFF; DIFFUSION BARRIERS; GROUND WATER; RADIONUCLIDE MIGRATION; CONTAINERS; DIFFUSION; NUMERICAL ANALYSIS; CONCENTRATION RATIO; Yucca Mountain ...

  13. Grain growth and phase stability of nanocrystalline cubic zirconia under ion irradiation

    SciTech Connect (OSTI)

    Zhang, Yanwen; Jiang, Weilin; Wang, Chong M.; Namavar, Fereydoon; Edmondson, Philip D.; Zhu, Zihua; Gao, Fei; Lian, Jie; Weber, William J.

    2010-11-10

    Grain growth, oxygen stoichiometry and phase stability of nanostructurally-stabilized zirconia (NSZ) in pure cubic phase are investigated under 2 MeV Au ion bombardment at 160 and 400 K to doses up to 35 displacements per atom (dpa). The NSZ films are produced by ion-beam-assisted deposition technique at room temperature with an average grain size of 7.7 nm. The grain size increases with dose, and follows a power law (n=6) to a saturation value of ~30 nm that decreases with temperature. Slower grain growth is observed under 400 K irradiations, as compared to 160 K irradiations, indicating that thermal grain growth is not activated and defect-stimulated grain growth is the dominating mechanism. While cubic phase is perfectly retained and no new phases are identified after the high-dose irradiations, reduction of oxygen in the irradiated NSZ films is detected. The ratio of O to Zr decreases from ~2.0 for the as-deposited films to ~1.65 after irradiation to ~35 dpa. Significant increase of oxygen vacancies in nanocrystalline zirconia suggests substantially enhanced oxygen diffusion under ion irradiation, a materials behavior far from equilibrium. The oxygen deficiency may be essential in stabilizing cubic phase to larger grain sizes.

  14. Irradiation-induced Ag nanocluster nucleation in silicate glasses: Analogy with photography

    SciTech Connect (OSTI)

    Espiau de Lamaestre, R.; Bea, H.; Bernas, H.; Belloni, J.; Marignier, J. L.

    2007-11-15

    The synthesis of Ag nanoclusters in soda lime silicate glasses and silica was studied by optical absorption and electron spin resonance experiments under both low (gamma ray) and high (MeV ion) deposited energy density irradiation conditions. Both types of irradiation create electrons and holes whose density and thermal evolution--notably via their interaction with defects--are shown to determine the clustering and growth rates of Ag nanocrystals. We thus establish the influence of redox interactions of defects and silver (poly)ions. The mechanisms are similar to the latent image formation in photography: Irradiation-induced photoelectrons are trapped within the glass matrix, notably on dissolved noble metal ions and defects, which are thus neutralized (reverse oxidation reactions are also shown to exist). Annealing promotes metal atom diffusion, which, in turn, leads to cluster nuclei formation. The cluster density depends not only on the irradiation fluence but also--and primarily--on the density of deposited energy and the redox properties of the glass. Ion irradiation (i.e., large deposited energy density) is far more effective in cluster formation, despite its lower neutralization efficiency (from Ag{sup +} to Ag{sup 0}) as compared to gamma photon irradiation.

  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. Experience with Palladium Diffusers in Tritium Processing

    SciTech Connect (OSTI)

    Motyka, T.; Clark, E.A.; Dauchess, D.A.; Heung, L.K.; Rabum, R.L.

    1995-01-27

    Hydrogen isotopes are separated from other gases by permeation through palladium and palladium-silver alloy diffusers in the Tritium Facilities at the US Department of Energy Savannah River Site (SRS). Diffusers have provided effective service for almost forty years. This paper is an overview of the operational experience with the various diffuser types that have been employed at SRS. Alternative technologies being developed at SRS for purifying hydrogen isotopes are also discussed.

  18. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant...

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

    Plant - November 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - November 2013 November 5, 2013 Review of Preparedness for Severe Natural Phenomena Events...

  19. Paducah Gaseous Diffusion Plant Final Environmental Assessment...

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

    Point of contact for more information: Robert Smith, Department of Energy-Paducah PDF icon Paducah Gaseous Diffusion Plant Final Environmental Assessment for Potential Land and ...

  20. 2-D Multi-Group Diffusion Program

    Energy Science and Technology Software Center (OSTI)

    1992-07-21

    The multigroup, two-dimensional neutron diffusion equations are solved in x-y, r-z, or r-theta geometry.

  1. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant...

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

    Gaseous Diffusion Plant (PORTS) contractor, Fluor-Babcock & Wilcox Portsmouth (FBP). ... 2013 Preliminary Notice of Violation, Fluor-B&W Portsmouth, LLC - July 8, 2014 ...

  2. Shortwave, Clear-sky Diffuse Irradiance in the 350 to 1050 nm...

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

    for the ET source function. The bottom figure includes differences caused by using the 5S and MODTRAN default ET spectra as opposed to the LOWTRAN default ET spectrum. This is...

  3. Microstructural, thermal and antibacterial properties of electron beam irradiated Bombyx mori silk fibroin films

    SciTech Connect (OSTI)

    Asha, S.; Sanjeev, Ganesh; Sangappa; Naik, Prashantha; Chandra, K. Sharat

    2014-04-24

    The Bombyx mori silk fibroin (SF) films were prepared by solution casting method and the effects of electron beam on structural, thermal and antibacterial responses of the prepared films were studied. The electron irradiation for different doses was carried out using 8 MeV Microtron facility at Mangalore University. The changes in microstructural parameters and thermal stability of the films were investigated using Wide Angle X-ray Scattering (WAXS) and thermogravimetric analysis (TGA) respectively. Both microstructuralline parameters (crystallite size and lattice strain (g in %)) and thermal stability of the irradiated films have increased with radiation dosage. Agar diffusion method demonstrated the antibacterial activity of SF film which was increased after irradiation on both Gram-positive and Gram-negative species.

  4. Microstructural Characterization of Irradiated U-7Mo/Al-5Si Dispersion to High Fission Density

    SciTech Connect (OSTI)

    J. Gan; B. D. Miller; D. D. Keiser, Jr.; A. B. Robinson; J. W. Madden; P. G. Medvedev; D. M. Wachs

    2014-11-01

    The fuel development program for research and test reactors calls for improved knowledge on the effect of microstructure on fuel performance in reactors. This work summarizes the recent TEM microstructural characterization of an irradiated U-7Mo/Al-5Si dispersion fuel plate (R3R050) irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory to 5.21021 fissions/cm3. While a large fraction of the fuel grains is decorated with large bubbles, there is no evidence showing interlinking of these large bubbles at the specified fission density. The attachment of solid fission product precipitates to the bubbles is likely the result of fission product diffusion into these bubbles. The process of fission gas bubble superlattice collapse appears through bubble coalescence. The results are compared with the previous TEM work of the dispersion fuels irradiated to lower fission density from the same fuel plate.

  5. Spatial disaggregation of satellite-derived irradiance using a high-resolution digital elevation model

    SciTech Connect (OSTI)

    Ruiz-Arias, Jose A.; Tovar-Pescador, Joaquin; Cebecauer, Tomas; Suri, Marcel

    2010-09-15

    Downscaling of the Meteosat-derived solar radiation ({proportional_to}5 km grid resolution) is based on decomposing the global irradiance and correcting the systematic bias of its components using the elevation and horizon shadowing that are derived from the SRTM-3 digital elevation model (3 arc sec resolution). The procedure first applies the elevation correction based on the difference between coarse and high spatial resolution. Global irradiance is split into direct, diffuse circumsolar and diffuse isotropic components using statistical models, and then corrections due to terrain shading and sky-view fraction are applied. The effect of reflected irradiance is analysed only in the theoretical section. The method was applied in the eastern Andalusia, Spain, and the validation was carried out for 22 days on April, July and December 2006 comparing 15-min estimates of the satellite-derived solar irradiance and observations from nine ground stations. Overall, the corrections of the satellite estimates in the studied region strongly reduced the mean bias of the estimates for clear and cloudy days from roughly 2.3% to 0.4%. (author)

  6. AGR 3/4 Irradiation Test Final As Run Report

    SciTech Connect (OSTI)

    Collin, Blaise P.

    2015-06-01

    Several fuel and material irradiation experiments have been planned for the Idaho National Laboratory Advanced Reactor Technologies Technology Development Office Advanced Gas Reactor Fuel Development and Qualification Program (referred to as the INL ART TDO/AGR fuel program hereafter), which supports the development and qualification of tristructural-isotropic (TRISO) coated particle fuel for use in HTGRs. The goals of these experiments are to provide irradiation performance data to support fuel process development, qualify fuel for normal operating conditions, support development and validation of fuel performance and fission product transport models and codes, and provide irradiated fuel and materials for post irradiation examination and safety testing (INL 05/2015). AGR-3/4 combined the third and fourth in this series of planned experiments to test TRISO coated low enriched uranium (LEU) oxycarbide fuel. This combined experiment was intended to support the refinement of fission product transport models and to assess the effects of sweep gas impurities on fuel performance and fission product transport by irradiating designed-to-fail fuel particles and by measuring subsequent fission metal transport in fuel-compact matrix material and fuel-element graphite. The AGR 3/4 fuel test was successful in irradiating the fuel compacts to the burnup and fast fluence target ranges, considering the experiment was terminated short of its initial 400 EFPD target (Collin 2015). Out of the 48 AGR-3/4 compacts, 42 achieved the specified burnup of at least 6% fissions per initial heavy-metal atom (FIMA). Three capsules had a maximum fuel compact average burnup < 10% FIMA, one more than originally specified, and the maximum fuel compact average burnup was <19% FIMA for the remaining capsules, as specified. Fast neutron fluence fell in the expected range of 1.0 to 5.5×1025 n/m2 (E >0.18 MeV) for all compacts. In addition, the AGR-3/4 experiment was globally successful in keeping the temperature in the twelve capsules relatively flat in a range of temperatures suitable for the measurement of fission product diffusion in compact matrix and structural graphite materials.

  7. 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.

  8. Correlation of Clinical and Dosimetric Factors With Adverse Pulmonary Outcomes in Children After Lung Irradiation

    SciTech Connect (OSTI)

    Venkatramani, Rajkumar; Kamath, Sunil; Wong, Kenneth; Malvar, Jemily; Sposto, Richard; Goodarzian, Fariba; Freyer, David R.; Keens, Thomas G.; and others

    2013-08-01

    Purpose: To identify the incidence and the risk factors for pulmonary toxicity in children treated for cancer with contemporary lung irradiation. Methods and Materials: We analyzed clinical features, radiographic findings, pulmonary function tests, and dosimetric parameters of children receiving irradiation to the lung fields over a 10-year period. Results: We identified 109 patients (75 male patients). The median age at irradiation was 13.8 years (range, 0.04-20.9 years). The median follow-up period was 3.4 years. The median prescribed radiation dose was 21 Gy (range, 0.4-64.8 Gy). Pulmonary toxic chemotherapy included bleomycin in 58.7% of patients and cyclophosphamide in 83.5%. The following pulmonary outcomes were identified and the 5-year cumulative incidence after irradiation was determined: pneumonitis, 6%; chronic cough, 10%; pneumonia, 35%; dyspnea, 11%; supplemental oxygen requirement, 2%; radiographic interstitial lung disease, 40%; and chest wall deformity, 12%. One patient died of progressive respiratory failure. Post-irradiation pulmonary function tests available from 44 patients showed evidence of obstructive lung disease (25%), restrictive disease (11%), hyperinflation (32%), and abnormal diffusion capacity (12%). Thoracic surgery, bleomycin, age, mean lung irradiation dose (MLD), maximum lung dose, prescribed dose, and dosimetric parameters between V{sub 22} (volume of lung exposed to a radiation dose ≥22 Gy) and V{sub 30} (volume of lung exposed to a radiation dose ≥30 Gy) were significant for the development of adverse pulmonary outcomes on univariate analysis. MLD, maximum lung dose, and V{sub dose} (percentage of volume of lung receiving the threshold dose or greater) were highly correlated. On multivariate analysis, MLD was the sole significant predictor of adverse pulmonary outcome (P=.01). Conclusions: Significant pulmonary dysfunction occurs in children receiving lung irradiation by contemporary techniques. MLD rather than prescribed dose should be used to perform risk stratification of patients receiving lung irradiation.

  9. 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 transducer and two magnetostrictive transducers have demonstrated reliable operation under irradiation. The irradiation is ongoing.

  10. Atomistic modeling of intrinsic and radiation-enhanced fission gas (Xe) diffusion in UO2 +/- x: Implications for nuclear fuel performance modeling

    SciTech Connect (OSTI)

    Giovanni Pastore; Michael R. Tonks; Derek R. Gaston; Richard L. Williamson; David Andrs; Richard Martineau

    2014-03-01

    Based on density functional theory (DFT) and empirical potential calculations, the diffusivity of fission gas atoms (Xe) in UO2 nuclear fuel has been calculated for a range of non-stoichiometry (i.e. UO2x), under both out-of-pile (no irradiation) and in-pile (irradiation) conditions. This was achieved by first deriving expressions for the activation energy that account for the type of trap site that the fission gas atoms occupy, which includes the corresponding type of mobile cluster, the charge state of these defects and the chemistry acting as boundary condition. In the next step DFT calculations were used to estimate migration barriers and internal energy contributions to the thermodynamic properties and calculations based on empirical potentials were used to estimate defect formation and migration entropies (i.e. pre-exponentials). The diffusivities calculated for out-of-pile conditions as function of the UO2x nonstoichiometrywere used to validate the accuracy of the diffusion models and the DFT calculations against available experimental data. The Xe diffusivity is predicted to depend strongly on the UO2x non-stoichiometry due to a combination of changes in the preferred Xe trap site and in the concentration of uranium vacancies enabling Xe diffusion, which is consistent with experiments. After establishing the validity of the modeling approach, it was used for studying Xe diffusion under in-pile conditions, for which experimental data is very scarce. The radiation-enhanced Xe diffusivity is compared to existing empirical models. Finally, the predicted fission gas diffusion rates were implemented in the BISON fuel performance code and fission gas release from a Ris fuel rod irradiation experiment was simulated. 2014 Elsevier B.V. All rights

  11. Finite-difference schemes for anisotropic diffusion

    SciTech Connect (OSTI)

    Es, Bram van; Koren, Barry; Blank, Hugo J. de

    2014-09-01

    In fusion plasmas diffusion tensors are extremely anisotropic due to the high temperature and large magnetic field strength. This causes diffusion, heat conduction, and viscous momentum loss, to effectively be aligned with the magnetic field lines. This alignment leads to different values for the respective diffusive coefficients in the magnetic field direction and in the perpendicular direction, to the extent that heat diffusion coefficients can be up to 10{sup 12} times larger in the parallel direction than in the perpendicular direction. This anisotropy puts stringent requirements on the numerical methods used to approximate the MHD-equations since any misalignment of the grid may cause the perpendicular diffusion to be polluted by the numerical error in approximating the parallel diffusion. Currently the common approach is to apply magnetic field-aligned coordinates, an approach that automatically takes care of the directionality of the diffusive coefficients. This approach runs into problems at x-points and at points where there is magnetic re-connection, since this causes local non-alignment. It is therefore useful to consider numerical schemes that are tolerant to the misalignment of the grid with the magnetic field lines, both to improve existing methods and to help open the possibility of applying regular non-aligned grids. To investigate this, in this paper several discretization schemes are developed and applied to the anisotropic heat diffusion equation on a non-aligned grid.

  12. Solid-state diffusion in amorphous zirconolite

    SciTech Connect (OSTI)

    Yang, C.; Dove, M. T.; Trachenko, K.; Zarkadoula, E.; Todorov, I. T.; Geisler, T.; Brazhkin, V. V.

    2014-11-14

    We discuss how structural disorder and amorphization affect solid-state diffusion, and consider zirconolite as a currently important case study. By performing extensive molecular dynamics simulations, we disentangle the effects of amorphization and density, and show that a profound increase of solid-state diffusion takes place as a result of amorphization. Importantly, this can take place at the same density as in the crystal, representing an interesting general insight regarding solid-state diffusion. We find that decreasing the density in the amorphous system increases pre-factors of diffusion constants, but does not change the activation energy in the density range considered. We also find that atomic species in zirconolite are affected differently by amorphization and density change. Our microscopic insights are relevant for understanding how solid-state diffusion changes due to disorder and for building predictive models of operation of materials to be used to encapsulate nuclear waste.

  13. 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.

  14. Lamp system with conditioned water coolant and diffuse reflector of polytetrafluorethylene(PTFE)

    DOE Patents [OSTI]

    Zapata, Luis E.; Hackel, Lloyd

    1999-01-01

    A lamp system with a very soft high-intensity output is provided over a large area by water cooling a long-arc lamp inside a diffuse reflector of polytetrafluorethylene (PTFE) and titanium dioxide (TiO.sub.2) white pigment. The water is kept clean and pure by a one micron particulate filter and an activated charcoal/ultraviolet irradiation system that circulates and de-ionizes and biologically sterilizes the coolant water at all times, even when the long-arc lamp is off.

  15. Diffusion and transport coefficients in synthetic opals

    SciTech Connect (OSTI)

    Sofo, J. O.; Mahan, G. D.; Department of Physics and Astronomy, The University of Tennessee, Knoxville, Tennessee 37996-1200

    2000-07-15

    Opals are structures composed of close-packed spheres in the size range of nano to micrometers. They are sintered to create small necks at the points of contact. We have solved the diffusion problem in such structures. The relation between the diffusion coefficient and the thermal and electrical conductivity is used to estimate the transport coefficients of opal structures as a function of the neck size and the mean free path of the carriers. The theory presented is also applicable to the diffusion problem in other periodic structures. (c) 2000 The American Physical Society.

  16. The AN neutron transport by nodal diffusion

    SciTech Connect (OSTI)

    Barbarino, A.; Tomatis, D.

    2013-07-01

    The two group diffusion model combined to a nodal approach in space is the preferred scheme for the industrial simulation of nuclear water reactors. The main selling point is the speed of computation, allowing a large number of parametric studies. Anyway, the drawbacks of the underlying diffusion equation may arise with highly heterogeneous interfaces, often encountered in modern UO{sub 2} and MO{sub x} fuel loading patterns, and boron less controlled systems. This paper aims at showing how the simplified AN transport model, equivalent to the well known SPN, can be implemented in standard diffusion codes with minor modifications. Some numerical results are illustrated. (authors)

  17. Determination of ion track radii in amorphous matrices via formation of nano-clusters by ion-beam irradiation

    SciTech Connect (OSTI)

    Buljan, M.; Karlusic, M.; Bogdanovic-Radovic, I.; Jaksic, M.; Radic, N.; Salamon, K.; Bernstorff, S.

    2012-09-03

    We report on a method for the determination of ion track radii, formed in amorphous materials by ion-beam irradiation. The method is based on the addition to an amorphous matrix of a small amount of foreign atoms, which easily diffuse and form clusters when the temperature is sufficiently increased. The irradiation causes clustering of these atoms, and the final separations of the formed clusters are dependent on the parameters of the ion-beam. Comparison of the separations between the clusters that are formed by ions with different properties in the same type of material enables the determination of ion-track radii.

  18. Ternary gas mixture for diffuse discharge switch (Patent) | DOEPatents

    Office of Scientific and Technical Information (OSTI)

    Ternary gas mixture for diffuse discharge switch Title: Ternary gas mixture for diffuse discharge switch A new diffuse discharge gas switch wherein a mixture of gases is used to ...

  19. Simulation of xenon, uranium vacancy and interstitial diffusion and grain boundary segregation in UO2

    SciTech Connect (OSTI)

    Andersson, Anders D.; Tonks, Michael R.; Casillas, Luis; Nerikar, Pankaj; Vyas, Shyam; Uberuaga, Blas P.; Stanek, Christopher R.

    2014-10-31

    In light water reactor fuel, gaseous fission products segregate to grain boundaries, resulting in the nucleation and growth of large intergranular fission gas bubbles. Based on the mechanisms established from density functional theory (DFT) and empirical potential calculations 1, continuum models for diffusion of xenon (Xe), uranium (U) vacancies and U interstitials in UO2 have been derived for both intrinsic conditions and under irradiation. Segregation of Xe to grain boundaries is described by combining the bulk diffusion model with a model for the interaction between Xe atoms and three different grain boundaries in UO2 ( ?5 tilt, ?5 twist and a high angle random boundary),as derived from atomistic calculations. All models are implemented in the MARMOT phase field code, which is used to calculate effective Xe and U diffusivities as well as redistribution for a few simple microstructures.

  20. Review of enhanced vapor diffusion in porous media

    SciTech Connect (OSTI)

    Webb, S.W.; Ho, C.K.

    1998-08-01

    Vapor diffusion in porous media in the presence of its own liquid has often been treated similar to gas diffusion. The gas diffusion rate in porous media is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. Existing data and models for enhanced vapor diffusion, including those in TOUGH2, are reviewed in this paper.

  1. Producing microchannels using graduated diffusion bonding of...

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

    of precision machined foils or sheets (laminates) to make a micro-channel reactor A novel multi-step process for the diffusion bonding of laminates National Energy Technology...

  2. Solar Energy Evolution and Diffusion Studies

    Broader source: Energy.gov [DOE]

    Through the Solar Energy Evolution and Diffusion Studies, or SEEDS, program, seven projects are investigating strategies to accelerate the pace of change for solar energy technologies as they are...

  3. Diffusion-controlled reactions modeling in Geant4-DNA

    SciTech Connect (OSTI)

    Karamitros, M.; Luan, S.; Bernal, M.A.; Allison, J.; Baldacchino, G.; Davidkova, M.; Francis, Z.; Friedland, W.; Ivantchenko, V.; Ivantchenko, A.; Mantero, A.; Nieminem, P.; Santin, G.; Tran, H.N.; Stepan, V.; Incerti, S.

    2014-10-01

    Context Under irradiation, a biological system undergoes a cascade of chemical reactions that can lead to an alteration of its normal operation. There are different types of radiation and many competing reactions. As a result the kinetics of chemical species is extremely complex. The simulation becomes then a powerful tool which, by describing the basic principles of chemical reactions, can reveal the dynamics of the macroscopic system. To understand the dynamics of biological systems under radiation, since the 80s there have been on-going efforts carried out by several research groups to establish a mechanistic model that consists in describing all the physical, chemical and biological phenomena following the irradiation of single cells. This approach is generally divided into a succession of stages that follow each other in time: (1) the physical stage, where the ionizing particles interact directly with the biological material; (2) the physico-chemical stage, where the targeted molecules release their energy by dissociating, creating new chemical species; (3) the chemical stage, where the new chemical species interact with each other or with the biomolecules; (4) the biological stage, where the repairing mechanisms of the cell come into play. This article focuses on the modeling of the chemical stage. Method This article presents a general method of speeding-up chemical reaction simulations in fluids based on the Smoluchowski equation and Monte-Carlo methods, where all molecules are explicitly simulated and the solvent is treated as a continuum. The model describes diffusion-controlled reactions. This method has been implemented in Geant4-DNA. The keys to the new algorithm include: (1) the combination of a method to compute time steps dynamically with a Brownian bridge process to account for chemical reactions, which avoids costly fixed time step simulations; (2) a kd tree data structure for quickly locating, for a given molecule, its closest reactants. The performance advantage is presented in terms of complexity, and the accuracy of the new algorithm is demonstrated by simulating radiation chemistry in the context of the Geant4-DNA project. Application The time-dependent radiolytic yields of the main chemical species formed after irradiation are computed for incident protons at different energies (from 50 MeV to 500 keV). Both the time-evolution and energy dependency of the yields are discussed. The evolution, at one microsecond, of the yields of hydroxyls and solvated electrons with respect to the linear energy transfer is compared to theoretical and experimental data. According to our results, at high linear energy transfer, modeling radiation chemistry in the trading compartment representation might be adopted.

  4. Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of...

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

    Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of Titanium Oxygen Diffusion (OD) Dramatically Improves Wear-Resistance of Titanium 2007 Diesel Engine-Efficiency & ...

  5. K-25 Gaseous Diffusion Process Building | Department of Energy

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

    other two being electromagnetic separation and liquid thermal diffusion. The S-50 liquid thermal diffusion plant, using convection to separate the isotopes in thousands of tall...

  6. EA-1927: Paducah Gaseous Diffusion Plant Potential Land and Facilities...

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

    Gaseous Diffusion Plant Potential Land and Facilities Transfers; McCracken County, Kentucky EA-1927: Paducah Gaseous Diffusion Plant Potential Land and Facilities Transfers; ...

  7. DOE - Office of Legacy Management -- Oak Ridge Gaseous Diffusion...

    Office of Legacy Management (LM)

    Oak Ridge Gaseous Diffusion Plant - TN 02 FUSRAP Considered Sites Site: Oak Ridge Gaseous Diffusion Plant (TN.02 ) Designated Name: Alternate Name: Location: Evaluation Year: Site...

  8. DOE - Office of Legacy Management -- Paducah Gaseous Diffusion...

    Office of Legacy Management (LM)

    Paducah Gaseous Diffusion Plant - KY 01 FUSRAP Considered Sites Site: Paducah Gaseous Diffusion Plant (KY.01 ) Designated Name: Alternate Name: Location: Evaluation Year: Site...

  9. Tritium Related Material Research -Irradiation Effect on Isotropic Graphite

    Office of Environmental Management (EM)

    Utilizing Heavy Ion-Irradiation- | Department of Energy Related Material Research -Irradiation Effect on Isotropic Graphite Utilizing Heavy Ion-Irradiation- Tritium Related Material Research -Irradiation Effect on Isotropic Graphite Utilizing Heavy Ion-Irradiation- Presentation from the 34th Tritium Focus Group Meeting held in Idaho Falls, Idaho on September 23-25, 2014. PDF icon Tritium Related Material Research -Irradiation Effect on Isotropic Graphite Utilizing Heavy Ion-Irradiation- More

  10. 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.

  11. Ab initio molecular dynamics of Al irradiation-induced processes during Al{sub 2}O{sub 3} growth

    SciTech Connect (OSTI)

    Music, Denis; Nahif, Farwah; Friederichsen, Niklas; Schneider, Jochen M.; Sarakinos, Kostas

    2011-03-14

    Al bombardment induced structural changes in {alpha}-Al{sub 2}O{sub 3} (R-3c) and {gamma}-Al{sub 2}O{sub 3} (Fd-3m) were studied using ab initio molecular dynamics. Diffusion and irradiation damage occur for both polymorphs in the kinetic energy range from 3.5 to 40 eV. However, for {gamma}-Al{sub 2}O{sub 3}(001) subplantation of impinging Al causes significantly larger irradiation damage and hence larger mobility as compared to {alpha}-Al{sub 2}O{sub 3}. Consequently, fast diffusion along {gamma}-Al{sub 2}O{sub 3}(001) gives rise to preferential {alpha}-Al{sub 2}O{sub 3}(0001) growth, which is consistent with published structure evolution experiments.

  12. 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...

  13. ARM - Measurement - Shortwave narrowband total upwelling irradiance

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

    Send Measurement : Shortwave narrowband total upwelling irradiance The rate at which radiant energy, in narrow bands of wavelengths shorter than approximately 4 mum, passes ...

  14. ARM - Measurement - Shortwave narrowband direct normal irradiance

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

    Send Measurement : Shortwave narrowband direct normal irradiance The rate at which radiant energy in narrow bands of wavelengths shorter than approximately 4mum, that comes ...

  15. 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 ...

  16. 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.

  17. Section 6

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

    8 ' toa 0 b ext,p (8, z) dz Session Papers 27 (1) Figure 1. Broadband (400 µm-1000 nm) downwelling total and diffuse solar irradiance measured by MFRSR on April 19, 1994 at the SGP ARM site. Figure 2. Aerosol Optical Depth (J ) estimated 8 from MFRSR data for April 19, 1994. Aerosol Optical Depth Estimates Based on Nephelometer Measurements at the Atmospheric Radiation Measurement Program Southern Great Plains Site M. H. Bergin and J. A. Ogren NOAA Climate Monitoring and Diagnostics Laboratory

  18. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant- January 2013

    Broader source: Energy.gov [DOE]

    Review of the Portsmouth Gaseous Diffusion Plant Work Planning and Control Activities Prior to Work Execution

  19. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant – November 2013

    Broader source: Energy.gov [DOE]

    Review of Preparedness for Severe Natural Phenomena Events at the Portsmouth Gaseous Diffusion Plant.

  20. K-25 Gaseous Diffusion Process Building | Department of Energy

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

    » Signature Facilities » K-25 Gaseous Diffusion Process Building K-25 Gaseous Diffusion Process Building K-25 Gaseous Diffusion Process Building New! K-25 Virtual Museum The K-25 plant, located on the southwestern end of the Oak Ridge reservation, used the gaseous diffusion method to separate uranium-235 from uranium-238. Based on the well-known principle that molecules of a lighter isotope would pass through a porous barrier more readily than molecules of a heavier one, gaseous diffusion

  1. Summary of Post Irradiation Examination Results of the AFIP-6 Failure

    SciTech Connect (OSTI)

    Adam Robinson; Daniel M. Wachs; Francine Rice; Danielle Perez

    2011-10-01

    The AFIP-6 test assembly was irradiated for one cycle in the Advanced Test Reactor at Idaho National Laboratory. The experiment was designed to test two monolithic fuel plates at power and burn-ups which bounded the operating conditions of both ATR and HFIR driver fuel. Both plates contain a solid U-Mo fuel foil with a zirconium diffusion barrier between 6061-aluminum cladding plates bonded by hot isostatic pressing. The experiment was designed with an orifice to restrict the coolant flow in order to obtain prototypic coolant temperature conditions. While these coolant temperatures were obtained, flow restriction resulted in low heat transfer coefficients and the failure of the fuel plates. The results from the post irradiation examinations and some observations of the failure mechanisms are outlined herein.

  2. Identification of periods of clear sky irradiance in time series of GHI measurements

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

    Reno, Matthew J.; Hansen, Clifford W.

    2016-01-18

    In this study, we present a simple algorithm for identifying periods of time with broadband global horizontal irradiance (GHI) similar to that occurring during clear sky conditions from a time series of GHI measurements. Other available methods to identify these periods do so by identifying periods with clear sky conditions using additional measurements, such as direct or diffuse irradiance. Our algorithm compares characteristics of the time series of measured GHI with the output of a clear sky model without requiring additional measurements. We validate our algorithm using data from several locations by comparing our results with those obtained from amore » clear sky detection algorithm, and with satellite and ground-based sky imagery.« less

  3. 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 on the as-fabricated fuel characterization and irradiation data. In addition to the extensive volume of results generated, the work also resulted in a number of novel analysis techniques and lessons learned that are being applied to the examination of fuel from subsequent TRISO fuel irradiations. This report provides a summary of the results obtained as part of the AGR-1 PIE campaign over its approximately 5-year duration.

  4. Irradiation-induced formation of a spinel phase at the FeCr/MgO interface

    SciTech Connect (OSTI)

    Xu, Yun; Yadav, Satyesh Kumar; Aguiar, Jeffery A.; Anderoglu, Osman; Baldwin, Jon Kevin; Wang, Yongqiang; Misra, Amit; Luo, Hongmei; Uberuaga, Blas P.; Li, Nan

    2015-04-27

    Oxide dispersion strengthened ferritic/martensitic alloys have attracted significant attention for their potential uses in future nuclear reactors and storage vessels, as the metal/oxide interfaces act as stable high-strength sinks for point defects while also dispersing helium. Here, in order to unravel the evolution and interplay of interface structure and chemistry upon irradiation in these types of materials, an atomically sharp FeCr/MgO interface was synthesized at 500 °C and separately annealed and irradiated with Ni3+ ions at 500 °C. After annealing, a slight enrichment of Cr atoms was observed at the interface, but no other structural changes were found. However, under irradiation, sufficient Cr diffuses across the interface into the MgO to form a Cr-enriched transition layer that contains spinel precipitates. First-principles calculations indicate that it is energetically favorable to incorporate Cr, but not Fe, substitutionally into MgO. Furthermore, our results indicate that irradiation can be used to form new phases and complexions at interfaces, which may have different radiation tolerance than the pristine structures.

  5. Irradiation-induced formation of a spinel phase at the FeCr/MgO interface

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

    Xu, Yun; Yadav, Satyesh Kumar; Aguiar, Jeffery A.; Anderoglu, Osman; Baldwin, Jon Kevin; Wang, Yongqiang; Misra, Amit; Luo, Hongmei; Uberuaga, Blas P.; Li, Nan

    2015-04-27

    Oxide dispersion strengthened ferritic/martensitic alloys have attracted significant attention for their potential uses in future nuclear reactors and storage vessels, as the metal/oxide interfaces act as stable high-strength sinks for point defects while also dispersing helium. Here, in order to unravel the evolution and interplay of interface structure and chemistry upon irradiation in these types of materials, an atomically sharp FeCr/MgO interface was synthesized at 500 °C and separately annealed and irradiated with Ni3+ ions at 500 °C. After annealing, a slight enrichment of Cr atoms was observed at the interface, but no other structural changes were found. However, undermore » irradiation, sufficient Cr diffuses across the interface into the MgO to form a Cr-enriched transition layer that contains spinel precipitates. First-principles calculations indicate that it is energetically favorable to incorporate Cr, but not Fe, substitutionally into MgO. Furthermore, our results indicate that irradiation can be used to form new phases and complexions at interfaces, which may have different radiation tolerance than the pristine structures.« less

  6. Analytical solutions to matrix diffusion problems

    SciTech Connect (OSTI)

    Keklinen, Pekka

    2014-10-06

    We report an analytical method to solve in a few cases of practical interest the equations which have traditionally been proposed for the matrix diffusion problem. In matrix diffusion, elements dissolved in ground water can penetrate the porous rock surronuding the advective flow paths. In the context of radioactive waste repositories this phenomenon provides a mechanism by which the area of rock surface in contact with advecting elements is greatly enhanced, and can thus be an important delay mechanism. The cases solved are relevant for laboratory as well for in situ experiments. Solutions are given as integral representations well suited for easy numerical solution.

  7. Self- and zinc diffusion in gallium antimonide

    SciTech Connect (OSTI)

    Nicols, Samuel Piers

    2002-03-26

    The technological age has in large part been driven by the applications of semiconductors, and most notably by silicon. Our lives have been thoroughly changed by devices using the broad range of semiconductor technology developed over the past forty years. Much of the technological development has its foundation in research carried out on the different semiconductors whose properties can be exploited to make transistors, lasers, and many other devices. While the technological focus has largely been on silicon, many other semiconductor systems have applications in industry and offer formidable academic challenges. Diffusion studies belong to the most basic studies in semiconductors, important from both an application as well as research standpoint. Diffusion processes govern the junctions formed for device applications. As the device dimensions are decreased and the dopant concentrations increased, keeping pace with Moore's Law, a deeper understanding of diffusion is necessary to establish and maintain the sharp dopant profiles engineered for optimal device performance. From an academic viewpoint, diffusion in semiconductors allows for the study of point defects. Very few techniques exist which allow for the extraction of as much information of their properties. This study focuses on diffusion in the semiconductor gallium antimonide (GaSb). As will become clear, this compound semiconductor proves to be a powerful one for investigating both self- and foreign atom diffusion. While the results have direct applications for work on GaSb devices, the results should also be taken in the broader context of III-V semiconductors. Results here can be compared and contrasted to results in systems such as GaAs and even GaN, indicating trends within this common group of semiconductors. The results also have direct importance for ternary and quaternary semiconductor systems used in devices such as high speed InP/GaAsSb/InP double heterojunction bipolar transistors (DHBT) [Dvorak, (2001)]. Many of the findings which will be reported here were previously published in three journal articles. Hartmut Bracht was the lead author on two articles on self-diffusion studies in GaSb [Bracht, (2001), (2000)], while this report's author was the lead author on Zn diffusion results [Nicols, (2001)]. Much of the information contained herein can be found in those articles, but a more detailed treatment is presented here.

  8. 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.

  9. Solar Irradiances Measured using SPN1 Radiometers: Uncertainties and Clues for Development

    SciTech Connect (OSTI)

    Badosa, Jordi; Wood, John; Blanc, Philippe; Long, Charles N.; Vuilleumier, Laurent; Demengel, Dominique; Haeffelin, Martial

    2014-12-08

    The fast development of solar radiation and energy applications, such as photovoltaic and solar thermodynamic systems, has increased the need for solar radiation measurement and monitoring, not only for the global component but also the diffuse and direct. End users look for the best compromise between getting close to state-of-the-art measurements and keeping capital, maintenance and operating costs to a minimum. Among the existing commercial options, SPN1 is a relatively low cost solar radiometer that estimates global and diffuse solar irradiances from seven thermopile sensors under a shading mask and without moving parts. This work presents a comprehensive study of SPN1 accuracy and sources of uncertainty, which results from laboratory experiments, numerical modeling and comparison studies between measurements from this sensor and state-of-the art instruments for six diverse sites. Several clues are provided for improving the SPN1 accuracy and agreement with state-of-the-art measurements.

  10. Time dependence of desorbed ground-state lithium atoms following pulsed-electron-beam irradiation of lithium fluoride

    SciTech Connect (OSTI)

    Green, T.A.; Loubriel, G.M.; Richards, P.M.; Tolk, N.H.; Haglund R.F. Jr.

    1987-01-15

    Recent experiments have shown that during the irradiation of lithium fluoride crystals by a chopped electron beam the signal of desorbed ground-state lithium atoms continues for times up to seconds in the beam-off period. A quantitative model is presented which connects the desorption of lithium atoms with the diffusion of lithium fluoride F centers to the surface. The model thus introduces a new source of time delay (F-center diffusion) in the desorption of ground-state metal atoms from alkali halides. Formerly it has been supposed that the delay occurred entirely during the surface desorption step. The model fits the experimental data very well, and should be applicable to other similar systems. For the cases considered here, F-center diffusion turns out to be the primary source of delay in the Li-atom signal. The model suggests some new directions for investigation.

  11. Comparison of fission product release predictions using PARFUME with results from the AGR-1 irradiation experiment

    SciTech Connect (OSTI)

    Blaise Collin

    2014-09-01

    This report documents comparisons between post-irradiation examination measurements and model predictions of silver (Ag), cesium (Cs), and strontium (Sr) release from selected tristructural isotropic (TRISO) fuel particles and compacts during the first irradiation test of the Advanced Gas Reactor program that occurred from December 2006 to November 2009 in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). The modeling was performed using the particle fuel model computer code PARFUME (PARticle FUel ModEl) developed at INL. PARFUME is an advanced gas-cooled reactor fuel performance modeling and analysis code (Miller 2009). It has been developed as an integrated mechanistic code that evaluates the thermal, mechanical, and physico-chemical behavior of fuel particles during irradiation to determine the failure probability of a population of fuel particles given the particle-to-particle statistical variations in physical dimensions and material properties that arise from the fuel fabrication process, accounting for all viable mechanisms that can lead to particle failure. The code also determines the diffusion of fission products from the fuel through the particle coating layers, and through the fuel matrix to the coolant boundary. The subsequent release of fission products is calculated at the compact level (release of fission products from the compact) but it can be assessed at the particle level by adjusting the diffusivity in the fuel matrix to very high values. Furthermore, the diffusivity of each layer can be individually set to a high value (typically 10-6 m2/s) to simulate a failed layer with no capability of fission product retention. In this study, the comparison to PIE focused on fission product release and because of the lack of failure in the irradiation, the probability of particle failure was not calculated. During the AGR-1 irradiation campaign, the fuel kernel produced and released fission products, which migrated through the successive layers of the TRISO-coated particle and potentially through the compact matrix. The release of these fission products was measured in PIE and modeled with PARFUME.

  12. 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...

  13. 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...

  14. Measurement of thermal conductivity in proton irradiated silicon...

    Office of Scientific and Technical Information (OSTI)

    Measurement of thermal conductivity in proton irradiated silicon Citation Details In-Document Search Title: Measurement of thermal conductivity in proton irradiated silicon We ...

  15. 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...

  16. 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 ...

  17. 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 ...

  18. 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...

  19. Solves the Multigroup Neutron Diffusion Equation

    Energy Science and Technology Software Center (OSTI)

    1995-06-23

    GNOMER is a program which solves the multigroup neutron diffusion equation in 1D, 2D and 3D cartesian geometry. The program is designed to calculate the global core power distributions (with thermohydraulic feedbacks), as well as power distribution and homogenized cross sections over a fuel assembly.

  20. Diffusion Databases for ICME | Department of Energy

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

    1 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer Evaluation PDF icon lm036_warren_2011_o.pdf More Documents & Publications Diffusion Databases for Mg-ICME Vehicle Technologies Office: 2010 Lightweight Materials R&D Annual Progress Report Low-Cost Direct Bonded Aluminum (DBA) Substrates

  1. 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.

  2. 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.

  3. 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.

  4. Molecular Modeling of Diffusion on a Crystalline PETN Surface

    SciTech Connect (OSTI)

    Lin, P; Khare, R; Gee, R H; Weeks, B L

    2007-07-13

    Surface diffusion on a PETN crystal was investigated by treating the surface diffusion as an activated process in the formalism of transition state theory. In particular, surface diffusion on the (110) and (101) facets, as well as diffusion between these facets, were considered. We successfully obtained the potential energy barriers required for PETN surface diffusion. Our results show that the (110) surface is more thermally active than the (101) surface and PETN molecules mainly diffuses from the (110) to (101) facet. These results are in good agreement with experimental observations and previous simulations.

  5. Fractionation of soil gases by diffusion of water vapor, gravitational settling, and thermal diffusion

    SciTech Connect (OSTI)

    Severinghaus, J.P.; Bender, M.L. [Univ. of Rhode Island, RI (United States)] [Univ. of Rhode Island, RI (United States); Keeling, R.F. [Scripps Institution of Oceanography, LaJolla, CA (United States)] [Scripps Institution of Oceanography, LaJolla, CA (United States); Broecker, W.S. [Lamont-Doherty Earth Observatory, Palisades, NY (United States)] [Lamont-Doherty Earth Observatory, Palisades, NY (United States)

    1996-03-01

    Air sampled from the moist unsaturated zone in a sand dune exhibits depletion in the heavy isotopes of N{sub 2} and O{sub 2}. We propose that the depletion is caused by a diffusive flux of water vapor out of the dune, which sweeps out the other gases, forcing them to diffuse back into the dune. The heavy isotopes of N{sub 2} and O{sub 2} diffuse back more slowly, resulting in a steady-state depletion of the heavy isotopesin the dune interior. We predict the effect`s magnitude with molecular diffusion theory and reproduce it in a laboratory simulation, finding good agreement between field, theory, and lab. The magnitude of the effect is governed by the ratio of the binary diffusivities against water vapor of a pair of gases, and increases {approximately} linearly with the difference between the water vapor mole fraction of the site and the advectively mixed reservoir with which it is in diffusive contact (in most cases the atmosphere). 32 refs., 1 fig., 3 tabs.

  6. Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces

    SciTech Connect (OSTI)

    James A. Smith; Jeffrey M. Lacy; Barry H. Rabin

    2014-07-01

    12. Other advances in QNDE and related topics: Preferred Session Laser-ultrasonics Developing A Laser Shockwave Model For Characterizing Diffusion Bonded Interfaces 41st Annual Review of Progress in Quantitative Nondestructive Evaluation Conference QNDE Conference July 20-25, 2014 Boise Centre 850 West Front Street Boise, Idaho 83702 James A. Smith, Jeffrey M. Lacy, Barry H. Rabin, Idaho National Laboratory, Idaho Falls, ID ABSTRACT: The US National Nuclear Security Agency has a Global Threat Reduction Initiative (GTRI) which is assigned with reducing the worldwide use of high-enriched uranium (HEU). A salient component of that initiative is the conversion of research reactors from HEU to low enriched uranium (LEU) fuels. An innovative fuel is being developed to replace HEU. The new LEU fuel is based on a monolithic fuel made from a U-Mo alloy foil encapsulated in Al-6061 cladding. In order to complete the fuel qualification process, the laser shock technique is being developed to characterize the clad-clad and fuel-clad interface strengths in fresh and irradiated fuel plates. The Laser Shockwave Technique (LST) is being investigated to characterize interface strength in fuel plates. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves to characterize interfaces in nuclear fuel plates. However the deposition of laser energy into the containment layer on specimen’s surface is intractably complex. The shock wave energy is inferred from the velocity on the backside and the depth of the impression left on the surface from the high pressure plasma pulse created by the shock laser. To help quantify the stresses and strengths at the interface, a finite element model is being developed and validated by comparing numerical and experimental results for back face velocities and front face depressions with experimental results. This paper will report on initial efforts to develop a finite element model for laser shock.

  7. 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....

  8. ARM - Measurement - Shortwave broadband total upwelling irradiance

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

    Send Measurement : Shortwave broadband total upwelling irradiance The rate at which radiant energy, at a wavelength between 0.4 and 4 mum, is being emitted upwards into a ...

  9. ARM - Measurement - Shortwave broadband direct normal irradiance

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

    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 ...

  10. ARM - Measurement - Longwave broadband upwelling irradiance

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

    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 ...

  11. ARM - Measurement - Longwave narrowband upwelling irradiance

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

    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 ...

  12. 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...

  13. Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

    SciTech Connect (OSTI)

    Goyal, Anuj; Phillpot, Simon R.; Subramanian, Gopinath; Andersson, David A.; Stanek, Chris R.; Uberuaga, Blas P.

    2015-03-03

    We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimum is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo simulations for both neutral and fully charged state of uranium single and divacancies. We calculate the effect of strain on migration barriers in the temperature range 800–1800 K for both vacancy types. Homogeneous strains as small as 2% have a considerable effect on diffusivity of both single and divacancies of uranium, with the effect of strain being more pronounced for single vacancies than divacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results indicate that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where divacancies dominate.

  14. Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

    SciTech Connect (OSTI)

    Goyal, Anuj; Phillpot, Simon R.; Subramanian, Gopinath; Andersson, David A.; Stanek, Chris R.; Uberuaga, Blas P.

    2015-03-03

    We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimum is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo simulations for both neutral and fully charged state of uranium single and divacancies. We calculate the effect of strain on migration barriers in the temperature range 8001800 K for both vacancy types. Homogeneous strains as small as 2% have a considerable effect on diffusivity of both single and divacancies of uranium, with the effect of strain being more pronounced for single vacancies than divacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results indicate that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where divacancies dominate.

  15. Development of Diffusion barrier coatings and Deposition Technologies for Mitigating Fuel Cladding Chemical Interactions (FCCI)

    SciTech Connect (OSTI)

    Sridharan, Kumar; Allen, Todd; Cole, James

    2013-02-27

    The goal of this project is to develop diffusion barrier coatings on the inner cladding surface to mitigate fuel-cladding chemical interaction (FCCI). FCCI occurs due to thermal and radiation enhanced inter-diffusion between the cladding and fuel materials, and can have the detrimental effects of reducing the effective cladding wall thickness and lowering the melting points of the fuel and cladding. The research is aimed at the Advanced Burner Reactor (ABR), a sodium-cooled fast reactor, in which higher burn-ups will exacerbate the FCCI problem. This project will study both diffusion barrier coating materials and deposition technologies. Researchers will investigate pure vanadium, zirconium, and titanium metals, along with their respective oxides, on substrates of HT-9, T91, and oxide dispersion-strengthened (ODS) steels; these materials are leading candidates for ABR fuel cladding. To test the efficacy of the coating materials, the research team will perform high-temperature diffusion couple studies using both a prototypic metallic uranium fuel and a surrogate—the rare-earth element lanthanum. Ion irradiation experiments will test the stability of the coating and the coating-cladding interface. A critical technological challenge is the ability to deposit uniform coatings on the inner surface of cladding. The team will develop a promising non-line-of-sight approach that uses nanofluids . Recent research has shown the feasibility of this simple yet novel approach to deposit coatings on test flats and inside small sections of claddings. Two approaches will be investigated: 1) modified electrophoretic deposition (MEPD) and 2) boiling nanofluids. The coatings will be evaluated in the as-deposited condition and after sintering.

  16. Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

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

    Goyal, Anuj; Phillpot, Simon R.; Subramanian, Gopinath; Andersson, David A.; Stanek, Chris R.; Uberuaga, Blas P.

    2015-03-03

    We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimummore » is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo simulations for both neutral and fully charged state of uranium single and divacancies. We calculate the effect of strain on migration barriers in the temperature range 800–1800 K for both vacancy types. Homogeneous strains as small as 2% have a considerable effect on diffusivity of both single and divacancies of uranium, with the effect of strain being more pronounced for single vacancies than divacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results indicate that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where divacancies dominate.« less

  17. A 20-Year Dataset of Downwelling Longwave Flux at the Arctic Surface from TOVS Satellite Data

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

    DOE R&D Accomplishments A 15 Year History of Growth and Development Introduction The DOE R&D Accomplishments website was developed to improve the visibility of DOE accomplishments by broadening and integrating access to important advances made possible by past DOE/predecessor research and development. It showcases the proud heritage of the Department's research and development and highlights benefits that are being realized now. Selection of electronic documents and Web page content is

  18. 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.

  19. 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)

  20. Direct normal irradiance related definitions and applications: The circumsolar issue

    SciTech Connect (OSTI)

    Blanc, P.; Espinar, B.; Geuder, N.; Gueymard, C.; Meyer, R.; Pitz-Paal, R.; Reinhardt, B.; Renne, D.; Segupta, M.; Wald, L.; Wilbert, S.

    2014-10-21

    The direct irradiance received on a plane normal to the sun, called direct normal irradiance (DNI), is of particular relevance to concentrated solar technologies, including concentrating solar thermal plants and concentrated photovoltaic systems. Following various standards from the International Organization for Standardization (ISO), the DNI definition is related to the irradiance from a small solid angle of the sky, centered on the position of the sun. Half-angle apertures of pyrheliometers measuring DNI have varied over time, up to ≈10°. The current recommendation of the World Meteorological Organization (WMO) for this half-angle is 2.5°. Solar concentrating collectors have an angular acceptance function that can be significantly narrower, especially for technologies with high concentration ratios. The disagreement between the various interpretations of DNI, from the theoretical definition used in atmospheric physics and radiative transfer modeling to practical definitions corresponding to specific measurements or conversion technologies is significant, especially in the presence of cirrus clouds or large concentration of aerosols. Under such sky conditions, the circumsolar radiation—i.e. the diffuse radiation coming from the vicinity of the sun—contributes significantly to the DNI ground measurement, although some concentrating collectors cannot utilize the bulk of it. These issues have been identified in the EU-funded projects MACC-II (Monitoring Atmospheric Composition and Climate-Interim Implementation) and SFERA (Solar Facilities for the European Research Area), and have been discussed within a panel of international experts in the framework of the Solar Heating and Cooling (SHC) program of the International Energy Agency’s (IEA’s) Task 46 “Solar Resource Assessment and Forecasting”. In accordance with these discussions, the terms of reference related to DNI are specified here. The important role of circumsolar radiation is evidenced, and its potential contribution is evaluated for typical atmospheric conditions. Thus, thorough analysis of performance of concentrating solar systems, it is recommended that, in addition to the conventional DNI related to 2.5° half-angle of today’s pyrheliometers, solar resource data sets also report the sunshape, the circumsolar contribution or the circumsolar ratio (CSR).

  1. Direct normal irradiance related definitions and applications: The circumsolar issue

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

    Blanc, P.; Espinar, B.; Geuder, N.; Gueymard, C.; Meyer, R.; Pitz-Paal, R.; Reinhardt, B.; Renne, D.; Segupta, M.; Wald, L.; et al

    2014-10-21

    The direct irradiance received on a plane normal to the sun, called direct normal irradiance (DNI), is of particular relevance to concentrated solar technologies, including concentrating solar thermal plants and concentrated photovoltaic systems. Following various standards from the International Organization for Standardization (ISO), the DNI definition is related to the irradiance from a small solid angle of the sky, centered on the position of the sun. Half-angle apertures of pyrheliometers measuring DNI have varied over time, up to ≈10°. The current recommendation of the World Meteorological Organization (WMO) for this half-angle is 2.5°. Solar concentrating collectors have an angular acceptancemore » function that can be significantly narrower, especially for technologies with high concentration ratios. The disagreement between the various interpretations of DNI, from the theoretical definition used in atmospheric physics and radiative transfer modeling to practical definitions corresponding to specific measurements or conversion technologies is significant, especially in the presence of cirrus clouds or large concentration of aerosols. Under such sky conditions, the circumsolar radiation—i.e. the diffuse radiation coming from the vicinity of the sun—contributes significantly to the DNI ground measurement, although some concentrating collectors cannot utilize the bulk of it. These issues have been identified in the EU-funded projects MACC-II (Monitoring Atmospheric Composition and Climate-Interim Implementation) and SFERA (Solar Facilities for the European Research Area), and have been discussed within a panel of international experts in the framework of the Solar Heating and Cooling (SHC) program of the International Energy Agency’s (IEA’s) Task 46 “Solar Resource Assessment and Forecasting”. In accordance with these discussions, the terms of reference related to DNI are specified here. The important role of circumsolar radiation is evidenced, and its potential contribution is evaluated for typical atmospheric conditions. Thus, thorough analysis of performance of concentrating solar systems, it is recommended that, in addition to the conventional DNI related to 2.5° half-angle of today’s pyrheliometers, solar resource data sets also report the sunshape, the circumsolar contribution or the circumsolar ratio (CSR).« less

  2. Diffusion barriers in modified air brazes

    DOE Patents [OSTI]

    Weil, Kenneth Scott; Hardy, John S.; Kim, Jin Yong; Choi, Jung-Pyung

    2010-04-06

    A method for joining two ceramic parts, or a ceramic part and a metal part, and the joint formed thereby. The method provides two or more parts, a braze consisting of a mixture of copper oxide and silver, a diffusion barrier, and then heats the braze for a time and at a temperature sufficient to form the braze into a bond holding the two or more parts together. The diffusion barrier is an oxidizable metal that forms either a homogeneous component of the braze, a heterogeneous component of the braze, a separate layer bordering the braze, or combinations thereof. The oxidizable metal is selected from the group Al, Mg, Cr, Si, Ni, Co, Mn, Ti, Zr, Hf, Pt, Pd, Au, lanthanides, and combinations thereof.

  3. Diffusion barriers in modified air brazes

    DOE Patents [OSTI]

    Weil, Kenneth Scott; Hardy, John S; Kim, Jin Yong; Choi, Jung-Pyung

    2013-04-23

    A method for joining two ceramic parts, or a ceramic part and a metal part, and the joint formed thereby. The method provides two or more parts, a braze consisting of a mixture of copper oxide and silver, a diffusion barrier, and then heats the braze for a time and at a temperature sufficient to form the braze into a bond holding the two or more parts together. The diffusion barrier is an oxidizable metal that forms either a homogeneous component of the braze, a heterogeneous component of the braze, a separate layer bordering the braze, or combinations thereof. The oxidizable metal is selected from the group Al, Mg, Cr, Si, Ni, Co, Mn, Ti, Zr, Hf, Pt, Pd, Au, lanthanides, and combinations thereof.

  4. Methodology and apparatus for diffuse photon mimaging

    DOE Patents [OSTI]

    Feng, Shechao C.; Zeng, Fanan; Zhao, Hui-Lin

    1997-12-09

    Non-invasive near infrared optical medical imaging devices for both hematoma detection in the brain and early tumor detection in the breast is achieved using image reconstruction which allows a mapping of the position dependent contrast diffusive propagation constants, which are related to the optical absorption coefficient and scattering coefficient in the tissue, at near infrared wavelengths. Spatial resolutions in the range of 5 mm for adult brain sizes and breast sizes can be achieved. The image reconstruction utilizes WKB approximation on most probable diffusion paths which has as lowest order approximation the straight line-of-sight between the plurality of sources and the plurality of detectors. The WKB approximation yields a set of linear equations in which the contrast optical absorption coefficients are the unknowns and for which signals can be generated to produce a pixel map of the contrast optical resolution of the scanned tissue.

  5. State protection under collective damping and diffusion

    SciTech Connect (OSTI)

    Ponte, M. A. de [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-590 Sao Carlos, SP (Brazil); Departamento de Fisica, Universidade Regional do Cariri, 63010-970 Juazeiro do Norte, CE (Brazil); Mizrahi, S. S. [Departamento de Fisica, Universidade Federal de Sao Carlos, 13565-905 Sao Carlos, SP (Brazil); Moussa, M. H. Y. [Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Caixa Postal 369, 13560-590 Sao Carlos, SP (Brazil)

    2011-07-15

    In this paper we provide a recipe for state protection in a network of oscillators under collective damping and diffusion. Our strategy is to manipulate the network topology, i.e., the way the oscillators are coupled together, the strength of their couplings, and their natural frequencies, in order to create a relaxation-diffusion-free channel. This protected channel defines a decoherence-free subspace (DFS) for nonzero-temperature reservoirs. Our development also furnishes an alternative approach to build up DFSs that offers two advantages over the conventional method: it enables the derivation of all the network-protected states at once, and also reveals, through the network normal modes, the mechanism behind the emergence of these protected domains.

  6. Methodology and apparatus for diffuse photon imaging

    DOE Patents [OSTI]

    Feng, S.C.; Zeng, F.; Zhao, H.L.

    1997-12-09

    Non-invasive near infrared optical medical imaging devices for both hematoma detection in the brain and early tumor detection in the breast is achieved using image reconstruction which allows a mapping of the position dependent contrast diffusive propagation constants, which are related to the optical absorption coefficient and scattering coefficient in the tissue, at near infrared wavelengths. Spatial resolutions in the range of 5 mm for adult brain sizes and breast sizes can be achieved. The image reconstruction utilizes WKB approximation on most probable diffusion paths which has as lowest order approximation the straight line-of-sight between the plurality of sources and the plurality of detectors. The WKB approximation yields a set of linear equations in which the contrast optical absorption coefficients are the unknowns and for which signals can be generated to produce a pixel map of the contrast optical resolution of the scanned tissue. 58 figs.

  7. Gas mixture for diffuse-discharge switch

    DOE Patents [OSTI]

    Christophorou, L.G.; Carter, J.G.; Hunter, S.R.

    1982-08-31

    Gaseous medium in a diffuse-discharge switch of a high-energy pulse generator is formed of argon combined with a compound selected from the group consisting of CF/sub 4/, C/sub 2/F/sub 6/, C/sub 3/F/sub 8/, n-C/sub 4/F/sub 10/, WF/sub 6/, (CF/sub 3/)/sub 2/S and (CF/sub 3/)/sub 2/O.

  8. Gas mixture for diffuse-discharge switch

    DOE Patents [OSTI]

    Christophorou, Loucas G. (Oak Ridge, TN); Carter, James G. (Knoxville, TN); Hunter, Scott R. (Oak Ridge, TN)

    1984-01-01

    Gaseous medium in a diffuse-discharge switch of a high-energy pulse generator is formed of argon combined with a compound selected from the group consisting of CF.sub.4, C.sub.2 F.sub.6, C.sub.3 F.sub.8, n-C.sub.4 F.sub.10, WF.sub.6, (CF.sub.3).sub.2 S and (CF.sub.3).sub.2 O.

  9. Glass Membrane For Controlled Diffusion Of Gases

    DOE Patents [OSTI]

    Shelby, James E.; Kenyon, Brian E.

    2001-05-15

    A glass structure for controlled permeability of gases includes a glass vessel. The glass vessel has walls and a hollow center for receiving a gas. The glass vessel contains a metal oxide dopant formed with at least one metal selected from the group consisting of transition metals and rare earth metals for controlling diffusion of the gas through the walls of the glass vessel. The vessel releases the gas through its walls upon exposure to a radiation source.

  10. The Digital Road to Scientific Knowledge Diffusion

    Office of Scientific and Technical Information (OSTI)

    Digital Road to Scientific Knowledge Diffusion A Faster, Better Way to Scientific Progress? By David E. Wojick, Walter L. Warnick, Bonnie C. Carroll, and June Crowe Introduction With the United States federal government spending over $130 billion annually for research and development, ways to increase the productivity of that research can have a significant return on investment. It is well known that all scientific advancement is based on work that has come before. Isaac Newton expressed this

  11. Diffusion method of seperating gaseous mixtures

    DOE Patents [OSTI]

    Pontius, Rex B.

    1976-01-01

    A method of effecting a relatively large change in the relative concentrations of the components of a gaseous mixture by diffusion which comprises separating the mixture into heavier and lighter portions according to major fraction mass recycle procedure, further separating the heavier portions into still heavier subportions according to a major fraction mass recycle procedure, and further separating the lighter portions into still lighter subportions according to a major fraction equilibrium recycle procedure.

  12. Diffuse-dynamic multiparameter diffractometry: A review

    SciTech Connect (OSTI)

    Molodkin, V. B. Shpak, A. P.; Kovalchuk, M. V.; Nosik, V. L.; Machulin, V. F.

    2010-12-15

    The results reported at the Conference on Application of X-Rays, Synchrotron Radiation, Neutrons, and Electrons in Nano-, Bio-, Information-, and Cognitive Technologies (RSNE-NBIC 2009) are briefly reviewed. This review is based on a cycle of studies [1-6] where a new method for studying the structure of real crystals-diffuse-dynamic multiparameter diffractometry (DDMD)-was proposed and substantiated.

  13. Distributed Energy Resources Market Diffusion Model

    SciTech Connect (OSTI)

    Maribu, Karl Magnus; Firestone, Ryan; Marnay, Chris; Siddiqui,Afzal S.

    2006-06-16

    Distributed generation (DG) technologies, such as gas-fired reciprocating engines and microturbines, have been found to be economically beneficial in meeting commercial-sector electrical, heating, and cooling loads. Even though the electric-only efficiency of DG is lower than that offered by traditional central stations, combined heat and power (CHP) applications using recovered heat can make the overall system energy efficiency of distributed energy resources (DER) greater. From a policy perspective, however, it would be useful to have good estimates of penetration rates of DER under various economic and regulatory scenarios. In order to examine the extent to which DER systems may be adopted at a national level, we model the diffusion of DER in the US commercial building sector under different technical research and technology outreach scenarios. In this context, technology market diffusion is assumed to depend on the system's economic attractiveness and the developer's knowledge about the technology. The latter can be spread both by word-of-mouth and by public outreach programs. To account for regional differences in energy markets and climates, as well as the economic potential for different building types, optimal DER systems are found for several building types and regions. Technology diffusion is then predicted via two scenarios: a baseline scenario and a program scenario, in which more research improves DER performance and stronger technology outreach programs increase DER knowledge. The results depict a large and diverse market where both optimal installed capacity and profitability vary significantly across regions and building types. According to the technology diffusion model, the West region will take the lead in DER installations mainly due to high electricity prices, followed by a later adoption in the Northeast and Midwest regions. Since the DER market is in an early stage, both technology research and outreach programs have the potential to increase DER adoption, and thus, shift building energy consumption to a more efficient alternative.

  14. Interactive Volume Rendering of Diffusion Tensor Data

    SciTech Connect (OSTI)

    Hlawitschka, Mario; Weber, Gunther; Anwander, Alfred; Carmichael, Owen; Hamann, Bernd; Scheuermann, Gerik

    2007-03-30

    As 3D volumetric images of the human body become an increasingly crucial source of information for the diagnosis and treatment of a broad variety of medical conditions, advanced techniques that allow clinicians to efficiently and clearly visualize volumetric images become increasingly important. Interaction has proven to be a key concept in analysis of medical images because static images of 3D data are prone to artifacts and misunderstanding of depth. Furthermore, fading out clinically irrelevant aspects of the image while preserving contextual anatomical landmarks helps medical doctors to focus on important parts of the images without becoming disoriented. Our goal was to develop a tool that unifies interactive manipulation and context preserving visualization of medical images with a special focus on diffusion tensor imaging (DTI) data. At each image voxel, DTI provides a 3 x 3 tensor whose entries represent the 3D statistical properties of water diffusion locally. Water motion that is preferential to specific spatial directions suggests structural organization of the underlying biological tissue; in particular, in the human brain, the naturally occuring diffusion of water in the axon portion of neurons is predominantly anisotropic along the longitudinal direction of the elongated, fiber-like axons [MMM+02]. This property has made DTI an emerging source of information about the structural integrity of axons and axonal connectivity between brain regions, both of which are thought to be disrupted in a broad range of medical disorders including multiple sclerosis, cerebrovascular disease, and autism [Mos02, FCI+01, JLH+99, BGKM+04, BJB+03].

  15. Diffusion Processes Satisfying a Conservation Law Constraint

    SciTech Connect (OSTI)

    Bakosi, J.; Ristorcelli, J. R.

    2014-03-04

    We investigate coupled stochastic differential equations governing N non-negative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires that a set of fluctuating variables be non-negative and (if appropriately normalized) sum to one. As a result, any stochastic differential equation model to be realizable must not produce events outside of the allowed sample space. We develop a set of constraints on the drift and diffusion terms of such stochastic models to ensure that both the non-negativity and the unit-sum conservation law constraint are satisfied as the variables evolve in time. We investigate the consequences of the developed constraints on the Fokker-Planck equation, the associated system of stochastic differential equations, and the evolution equations of the first four moments of the probability density function. We show that random variables, satisfying a conservation law constraint, represented by stochastic diffusion processes, must have diffusion terms that are coupled and nonlinear. The set of constraints developed enables the development of statistical representations of fluctuating variables satisfying a conservation law. We exemplify the results with the bivariate beta process and the multivariate Wright-Fisher, Dirichlet, and Lochner’s generalized Dirichlet processes.

  16. Diffusion Processes Satisfying a Conservation Law Constraint

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

    Bakosi, J.; Ristorcelli, J. R.

    2014-03-04

    We investigate coupled stochastic differential equations governing N non-negative continuous random variables that satisfy a conservation principle. In various fields a conservation law requires that a set of fluctuating variables be non-negative and (if appropriately normalized) sum to one. As a result, any stochastic differential equation model to be realizable must not produce events outside of the allowed sample space. We develop a set of constraints on the drift and diffusion terms of such stochastic models to ensure that both the non-negativity and the unit-sum conservation law constraint are satisfied as the variables evolve in time. We investigate the consequencesmore » of the developed constraints on the Fokker-Planck equation, the associated system of stochastic differential equations, and the evolution equations of the first four moments of the probability density function. We show that random variables, satisfying a conservation law constraint, represented by stochastic diffusion processes, must have diffusion terms that are coupled and nonlinear. The set of constraints developed enables the development of statistical representations of fluctuating variables satisfying a conservation law. We exemplify the results with the bivariate beta process and the multivariate Wright-Fisher, Dirichlet, and Lochner’s generalized Dirichlet processes.« less

  17. Vapor Barriers or Vapor Diffusion Retarders | Department of Energy

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

    Weatherize » Moisture Control » Vapor Barriers or Vapor Diffusion Retarders Vapor Barriers or Vapor Diffusion Retarders Vapor diffusion retarders installed in a crawlspace can be part of an overall moisture control strategy for your home. | Photo courtesy of Dennis Schroeder, NREL. Vapor diffusion retarders installed in a crawlspace can be part of an overall moisture control strategy for your home. | Photo courtesy of Dennis Schroeder, NREL. In most U.S. climates, vapor barriers, or -- more

  18. Anti-diffusion metal coated O-rings

    DOE Patents [OSTI]

    Biallas, George Herman; Boyce, James Reid

    2016-03-22

    A method for inhibiting diffusion of gases and/or transmission of photons through elastomeric seals and a diffusion inhibiting elastomeric seal wherein at least a portion of the surface of a diffusion inhibiting elastomeric seal is coated with a compatibly-deformable, malleable metal coating.

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

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

    Gamma Irradiation Facility Working with SRNL Our Facilities - Gamma Irradiation Facility SRNL's Gamma Irradiation Facility is equipped with devices 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 determine the life expectancy of components to be used in a radioactive environment or to study material performance under a variety of conditions

  20. RERTR-12 Post-irradiation Examination Summary Report

    SciTech Connect (OSTI)

    Rice, Francine; Williams, Walter; Robinson, Adam; Harp, Jason; Meyer, Mitch; Rabin, Barry

    2015-02-01

    The following report contains the results and conclusions for the post irradiation examinations performed on RERTR-12 Insertion 2 experiment plates. These exams include eddy-current testing to measure oxide growth; neutron radiography for evaluating the condition of the fuel prior to sectioning and determination of fuel relocation and geometry changes; gamma scanning to provide relative measurements for burnup and indication of fuel- and fission-product relocation; profilometry to measure dimensional changes of the fuel plate; analytical chemistry to benchmark the physics burnup calculations; metallography to examine the microstructural changes in the fuel, interlayer and cladding; and microhardness testing to determine the material-property changes of the fuel and cladding. These characterization activities are tailored specifically to define: • The mechanical response of fuel meat, cladding, and interlayers, including diffusion barrier integrity • Whether geometry is stable and predictable; that changes in channel gap do not compromise ability to cool fuel • That fuel performance is known and predictable • A limited set of physical properties that are important for the analysis of fuel burnup limits • Whether swelling is stable and predictable.

  1. Unsteady behavior of locally strained diffusion flames affected by curvature and preferential diffusion

    SciTech Connect (OSTI)

    Yoshida, Kenji; Takagi, Toshimi

    1999-07-01

    Experimental and numerical studies are made of transient H{sub 2}/N{sub 2}--air counterflow diffusion flames unsteadily strained by an impinging micro jet. Two-dimensional temperature measurements by laser Rayleigh scattering method and numerical computations taking into account detailed chemical kinetics are conducted paying attention to transient local extinction and reignition in relation to the unsteadiness, flame curvature and preferential diffusion effects. The results are as follows. (1) Transient local flame extinction is observed where the micro jet impinges. But, the transient flame can survive instantaneously in spite of quite high stretch rate where the steady flame cannot exist. (2) Reignition is observed after the local extinction due to the micro air jet impingement. The temperature after reignition becomes significantly higher than that of the original flame. This high temperature is induced by the concentration of H{sub 2} species due to the preferential diffusion in relation to the concave curvature. The predicted behaviors of the local transient extinction and reignition are well confirmed by the experiments. (3) The reignition is induced after the formation of combustible premixed gas mixture and the consequent flame propagation. (4) The reignition is hardly observed after the extinction by micro fuel jet impingement. This is due to the dilution of H{sub 2} species induced by the preferential diffusion in relation to the convex curvature. (5) The maximum flame temperature cannot be rationalized by the stretch rate but changes widely depending on the unsteadiness and the flame curvature in relation with preferential diffusion.

  2. Consideration of Grain Size Distribution in the Diffusion of Fission Gas to Grain Boundaries

    SciTech Connect (OSTI)

    Paul C. Millett; Yongfeng Zhang; Michael R. Tonks; S. B. Biner

    2013-09-01

    We analyze the accumulation of fission gas on grain boundaries in a polycrystalline microstructure with a distribution of grain sizes. The diffusion equation is solved throughout the microstructure to evolve the gas concentration in space and time. Grain boundaries are treated as infinite sinks for the gas concentration, and we monitor the cumulative gas inventory on each grain boundary throughout time. We consider two important cases: first, a uniform initial distribution of gas concentration without gas production (correlating with post-irradiation annealing), and second, a constant gas production rate with no initial gas concentration (correlating with in-reactor conditions). The results show that a single-grain-size model, such as the Booth model, over predicts the gas accumulation on grain boundaries compared with a polycrystal with a grain size distribution. Also, a considerable degree of scatter, or variability, exists in the grain boundary gas accumulation when comparing all of the grain boundaries in the microstructure.

  3. Role of Trapping Impurities on He Desorption and Clustering in Irradiated a-Fe

    SciTech Connect (OSTI)

    Ortiz, Christophe J.; Caturla, Maria Jose; Fu, Chu Chun; Willaime, Francois

    2008-07-01

    It is well-known that impurities affect the migration of intrinsic point defects in metals. For instance, carbon is a common impurity in Fe that significantly retards diffusion of vacancies. Under fusion irradiation conditions, high levels of He are produced by transmutation reactions. This element strongly interacts with vacancies produced during irradiation and agglomerate into stable He-vacancy clusters that can deteriorate the mechanical properties of the material. A physically-based model accounting for the interactions between He, point defects (interstitials and vacancies) and trapping impurities is therefore necessary to understand and predict damage evolution in Fe. We have used a multi-scale approach to predict the evolution of He in the presence of impurities in irradiated Fe. Density Functional Theory (DFT) calculations were performed to investigate the migration mechanisms and to determine the activation energies of the different atomistic processes. The influence of impurities - such as carbon - on the binding energies of small He-vacancy clusters was also studied. Using the information obtained by DFT a physically-based model was developed and implemented in a kinetic Monte Carlo (kMC) code to follow the evolution of He in Fe. In addition, a model based on the rate theory (RT) was developed in order to achieve larger simulation times and volumes. Results obtained with this model, which is based on a mean field approximation are compared to those obtained with kMC. Using this multi-scale approach, the simulation results are used to interpret the different stages of thermal He desorption experiments and to determine the predominant migration mechanism. The influence of impurities which affect the diffusion of point defects or modify the binding energies of He-vacancy type clusters is also studied. (authors)

  4. Oxygen diffusion of anodic surface oxide film on titanium studied by Auger electron spectroscopy. [Oxygen diffusivity

    SciTech Connect (OSTI)

    Wang, P.S.; Wittberg, T.N.; Keil, R.G.

    1982-01-01

    TiO/sub 2/ films of about 1000 A were grown onto titanium foils anodically under galvanostatic conditions at 20 mA/cm/sup 2/ in saturated aqueous solutions of ammonium tetraborate. The samples were then aged at 450, 500, and 550/sup 0/C, and oxygen diffusion was observed by Auger electron spectroscopy (AES) profilings. The oxygen diffusivities were calculated by Fick's Second Law, using the Boltzmann-Matano solution, to be 9.4 x 10/sup -17/, 2.6 x 10/sup -16/, and 1.2 x 10/sup -15/ cm/sup 2//sec at 450, 500, and 550/sup 0/C, respectively. The diffusivities obtained by this method were also compared with those obtained using an exact solution to Fick's Second Law. The activation energy was calculated to be 30 kcal/mole.

  5. Phenomena in oscillating downward propagating flames induced by external laser irradiation method

    SciTech Connect (OSTI)

    Park, June Sung; Fujita, Osamu; Honko, Teruaki; Yamada, Yuichiro; Ito, Hiroyuki; Nakamura, Yuji [Division of Mechanical and Space Engineering, Hokkaido University, Kita13 Nishi8, Kita-ku, Sapporo, Hokkaido (Japan)

    2010-11-15

    Experiments in C{sub 2}H{sub 4}/CO{sub 2}-O{sub 2} premixed flames (Le < 1) propagating downwardly in a tube have been conducted to observe transition phenomena from laminar flame front to turbulent flame propagation triggered by external laser irradiation method. To investigate the exact motions of flame tip fluctuation at the initial moment of irradiating CO{sub 2} laser, the completely flat flame front is selected as a default flame, which is corresponding to the primary acoustic instability as reported by Searby (1992). According to the time-resolved observation, the flame front exposed to CO{sub 2} laser beam shows extremely unstable flame motions in which highly curved flame front towards unburned mixture is subject to diffusive-thermal instability. Then, the sudden enhanced burning state (increased flame surface) caused by flame instability induces the secondary acoustic instability which is akin to the observation in Ref. In the present study, we report the detailed descriptions of flame fronts on the transient behaviors leading the primary acoustic instability to turbulent motions actively induced by the absorption of externally irradiated CO{sub 2} laser beam. (author)

  6. Resolving and measuring diffusion in complex interfaces: Exploring new capabilities

    SciTech Connect (OSTI)

    Alam, Todd M.

    2015-09-01

    This exploratory LDRD targeted the use of a new high resolution spectroscopic diffusion capabilities developed at Sandia to resolve transport processes at interfaces in heterogeneous polymer materials. In particular, the combination of high resolution magic angle spinning (HRMAS) nuclear magnetic resonance (NMR) spectroscopy with pulsed field gradient (PFG) diffusion experiments were used to directly explore interface diffusion within heterogeneous polymer composites, including measuring diffusion for individual chemical species in multi-component mixtures. Several different types of heterogeneous polymer systems were studied using these HRMAS NMR diffusion capabilities to probe the resolution limitations, determine the spatial length scales involved, and explore the general applicability to specific heterogeneous systems. The investigations pursued included a) the direct measurement of the diffusion for poly(dimethyl siloxane) polymer (PDMS) on nano-porous materials, b) measurement of penetrant diffusion in additive manufactures (3D printed) processed PDMS composites, and c) the measurement of diffusion in swollen polymers/penetrant mixtures within nano-confined aluminum oxide membranes. The NMR diffusion results obtained were encouraging and allowed for an improved understanding of diffusion and transport processes at the molecular level, while at the same time demonstrating that the spatial heterogeneity that can be resolved using HRMAS NMR PFG diffusion experiment must be larger than ~μm length scales, expect for polymer transport within nanoporous carbons where additional chemical resolution improves the resolvable heterogeneous length scale to hundreds of nm.

  7. 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.

  8. 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.

  9. 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).

  10. Commercial Building Partnerships Replication and Diffusion

    SciTech Connect (OSTI)

    Antonopoulos, Chrissi A.; Dillon, Heather E.; Baechler, Michael C.

    2013-09-16

    This study presents findings from survey and interview data investigating replication efforts of Commercial Building Partnership (CBP) partners that worked directly with the Pacific Northwest National Laboratory (PNNL). PNNL partnered directly with 12 organizations on new and retrofit construction projects, which represented approximately 28 percent of the entire U.S. Department of Energy (DOE) CBP program. Through a feedback survey mechanism, along with personal interviews, PNNL gathered quantitative and qualitative data relating to replication efforts by each organization. These data were analyzed to provide insight into two primary research areas: 1) CBP partners’ replication efforts of technologies and approaches used in the CBP project to the rest of the organization’s building portfolio (including replication verification), and, 2) the market potential for technology diffusion into the total U.S. commercial building stock, as a direct result of the CBP program. The first area of this research focused specifically on replication efforts underway or planned by each CBP program participant. Factors that impact replication include motivation, organizational structure and objectives firms have for implementation of energy efficient technologies. Comparing these factors between different CBP partners revealed patterns in motivation for constructing energy efficient buildings, along with better insight into market trends for green building practices. The second area of this research develops a diffusion of innovations model to analyze potential broad market impacts of the CBP program on the commercial building industry in the United States.

  11. Reaction and diffusion in turbulent combustion

    SciTech Connect (OSTI)

    Pope, S.B.

    1993-12-01

    The motivation for this project is the need to obtain a better quantitative understanding of the technologically-important phenomenon of turbulent combustion. In nearly all applications in which fuel is burned-for example, fossil-fuel power plants, furnaces, gas-turbines and internal-combustion engines-the combustion takes place in a turbulent flow. Designers continually demand more quantitative information about this phenomenon-in the form of turbulent combustion models-so that they can design equipment with increased efficiency and decreased environmental impact. For some time the PI has been developing a class of turbulent combustion models known as PDF methods. These methods have the important virtue that both convection and reaction can be treated without turbulence-modelling assumptions. However, a mixing model is required to account for the effects of molecular diffusion. Currently, the available mixing models are known to have some significant defects. The major motivation of the project is to seek a better understanding of molecular diffusion in turbulent reactive flows, and hence to develop a better mixing model.

  12. Distributed Wind Diffusion Model Overview (Presentation)

    SciTech Connect (OSTI)

    Preus, R.; Drury, E.; Sigrin, B.; Gleason, M.

    2014-07-01

    Distributed wind market demand is driven by current and future wind price and performance, along with several non-price market factors like financing terms, retail electricity rates and rate structures, future wind incentives, and others. We developed a new distributed wind technology diffusion model for the contiguous United States that combines hourly wind speed data at 200m resolution with high resolution electricity load data for various consumer segments (e.g., residential, commercial, industrial), electricity rates and rate structures for utility service territories, incentive data, and high resolution tree cover. The model first calculates the economics of distributed wind at high spatial resolution for each market segment, and then uses a Bass diffusion framework to estimate the evolution of market demand over time. The model provides a fundamental new tool for characterizing how distributed wind market potential could be impacted by a range of future conditions, such as electricity price escalations, improvements in wind generator performance and installed cost, and new financing structures. This paper describes model methodology and presents sample results for distributed wind market potential in the contiguous U.S. through 2050.

  13. 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.

  14. 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.

  15. 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.

  16. Controlling diffusion for a self-healing radiation tolerant nanostructured ferritic alloy

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

    Miller, Michael K.; Parish, Chad M.; Bei, Hongbin

    2014-12-18

    Diffusion plays a major role in the stability of microstructures to extreme conditions of high temperature and high doses of irradiation. In nanostructured ferritic alloys, first principle calculations indicate that the binding energy of vacancies is reduced by the presence of oxygen, titanium and yttrium atoms. Therefore, the number of free vacancies available for diffusion can be greatly reduced. The mechanical properties of these alloys, compared to traditional wrought alloys of similar composition and grain structure, is distinctly different, and the ultrafine grained alloy is distinguished by a high number density of Ti–Y–O-enriched nanoclusters and solute clusters, which drives themore » mechanical response. When a displacement cascade interacts with a nanocluster, the solute atoms are locally dispersed into the matrix by ballistic collisions, but immediately a new nanocluster reforms due to the local supersaturation of solutes and vacancies until the excess vacancies are consumed. Furthermore, the result of these processes is a structural material for advanced energy systems with a microstructure that is self-healing and tolerant to high doses of radiation and high temperatures.« less

  17. 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-induced microstructures mapped spatially and temporally, microstructural evolution during post-irradiation annealing, and atomistic modeling of defect formation and transport energetics will provide new, critical understanding about property changes in ZrC. The behavior of materials under irradiation is determined by the balance between damage production, defect clustering, and lattice response. In order to predict those effects at high temperatures so targeted testing can be expanded and extrapolated beyond the known database, it is necessary to determine the defect energetics and mobilities as these control damage accumulation and annealing. In particular, low-temperature irradiations are invaluable for determining the regions of defect mobility. Computer simulation techniques are particularly useful for identifying basic defect properties, especially if closely coupled with a well-constructed and complete experimental database. The close coupling of calculation and experiment in this project will provide mutual benchmarking and allow us to glean a deeper understanding of the irradiation response of ZrC, which can then be applied to the prediction of its behavior in reactor conditions.

  18. Anomalous grain growth in the surface region of a nanocrystalline CeO2 film under low-temperature heavy ion irradiation

    SciTech Connect (OSTI)

    Edmondson, Philip D.; Zhang, Yanwen; Moll, Sandra J.; Varga, Tamas; Namavar, Fereydoon; Weber, William J.

    2012-06-15

    Grain growth and phase stability of nanocrystalline ceria are investigated under ion irradiation at different temperatures. Irradiations at temperatures of 300 and 400 K result in uniform grain growth throughout the film. Anomalous grain growth is observed in thin films of nanocrystalline ceria under 3 MeV Au+ irradiation at 160 K. At this low temperature, significant grain growth is observed within 100 nm from the surface, no obvious growth is detected in the rest of the films. While the grain growth is attributed to a defect-stimulated mechanism at room temperature and above, a defect diffusion-limited mechanism is significant at low temperature with the primary defect responsible being the oxygen vacancy. The nanocrystalline grains remain in the cubic phase regardless of defect kinetics.

  19. Importance of Diffusion in Methanol Photochemistry on TiO2(110)

    SciTech Connect (OSTI)

    Shen, Mingmin; Acharya, Danda P.; Dohnalek, Zdenek; Henderson, Michael A.

    2012-12-06

    The photoactivity of methanol on the rutile TiO2(110) surface is shown to depend on the ability of methanol to diffuse on the surface and find sites active for its thermal dissociation to methoxy. Temperature programmed desorption (TPD) results show that the extent of methanol photodecomposition to formaldehyde is negligible on the clean TiO2(110) surface at 100 K due to a scarcity of sites that can convert (photoinactive) methanol to (photoactive) methoxy. The extent of photoactivity at 100 K significantly increases when methanol is coadsorbed with oxygen, however only those molecules able to adsorb near (next to) a coadsorbed oxygen species are active. Preannealing coadsorbed methanol and oxygen to above 200 K prior to UV irradiation results in a significant increase in photoactivity. Scanning tunneling microscopy (STM) images clearly show that the advent of increased photoactivity in TPD correlates with the onset of methanol diffusion along the surfaces Ti4+ rows at ~200 K. These results demonstrate that optimizing thermal processes (such as diffusion or proton transfer reactions) can be critical to maximizing photocatalytic reactivity on TiO2 surfaces. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle under contract DEAC05-76RL01830. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  20. Microstructural Characteristics of HIP-bonded Monolithic Nuclear Fuels with a Diffusion Barrier

    SciTech Connect (OSTI)

    Jan-Fong Jue; Dennis D. Keiser, Jr.; Cynthia R. Breckenridge; Glenn A. Moore; Mitchell K. Meyer

    2014-05-01

    Due to the limitation of maximum uranium load achievable by dispersion fuel type, the Global Threat Reduction Initiative (GTRI) is developing an advanced monolithic fuel to convert US high performance research reactors to low-enriched uranium. Hot-isostatic-press bonding was the single process down-selected to bond monolithic U-Mo fuel meat to aluminum alloy cladding. A diffusion barrier was applied to the U–Mo fuel meat by roll-bonding process to prevent extensive interaction between fuel meat and aluminum-alloy cladding. Microstructural characterization was performed on fresh fuel plates fabricated at Idaho National Laboratory. Interfaces between fuel meat, cladding, and diffusion barrier, as well as U–10Mo fuel meat and Al–6061 cladding were characterized by scanning electron microscopy. Preliminary results indicate that the interfaces contain many different phases while decomposition, second phases, and chemical banding were also observed in the fuel meat. The important attributes of the HIP-bonded monolithic fuel are • A typical Zr diffusion barrier of thickness 25 µm • Transverse cross section that exhibits relatively equiaxed grains with an average grain diameter of 10 µm • Chemical banding, in some areas more than 100 µm in length, that is very pronounced in longitudinal (i.e., rolling) direction with Mo concentration varying from 7–13 wt% • Decomposed areas containing plate-shaped low-Mo phase • A typical Zr/cladding interaction layer of thickness 1-2 µm • A visible UZr2 bearing layer of thickness 1-2 µm • Mo-rich precipitates (mainly Mo2Zr, forming a layer in some areas) followed by a Mo-depleted sub-layer between the visible UZr2-bearing layer and the U–Mo matrix • No excessive interaction between cladding and the uncoated fuel edge • Cladding-to-cladding bonding that exhibits no cracks or porosity with second phases high in Mg, Si, and O decorating the bond line. • Some of these attributes might be critical to the irradiation performance of monolithic U-10Mo nuclear fuel. There are several issues or concerns that warrant more detailed study, such as precipitation along cladding-to-cladding bond line, chemical banding, uncovered fuel-zone edge, and interaction layer between U–Mo fuel meat and zirconium. Future post-irradiation examination results will focus, among other things, on identifying in-reactor failure mechanisms and, eventually, directing further fresh fuel characterization efforts.

  1. Overview of SIMS-Based Experimental Studies of Tracer Diffusion in Solids and Application to Mg Self-Diffusion

    SciTech Connect (OSTI)

    Kulkarni, Nagraj S.; Bruce Warmack, Robert J.; Radhakrishnan, Bala; Hunter, Jerry L.; Sohn, Yongho; Coffey, Kevin R.; Murch, Graeme E.; Belova, Irina V.

    2014-09-23

    Tracer diffusivities provide the most fundamental information on diffusion in materials and are the foundation of robust diffusion databases. Compared to traditional radiotracer techniques that utilize radioactive isotopes, the secondary ion mass spectrometry (SIMS) based thin-film technique for tracer diffusion is based on the use of enriched stable isotopes that can be accurately profiled using SIMS. Experimental procedures & techniques that are utilized for the measurement of tracer diffusion coefficients are presented for pure magnesium, which presents some unique challenges due to the ease of oxidation. The development of a modified Shewmon-Rhines diffusion capsule for annealing Mg and an ultra-high vacuum (UHV) system for sputter deposition of Mg isotopes are discussed. Optimized conditions for accurate SIMS depth profiling in polycrystalline Mg are provided. An automated procedure for the correction of heat-up and cool-down times during tracer diffusion annealing is discussed. The non-linear fitting of a SIMS depth profile data using the thin film Gaussian solution to obtain the tracer diffusivity along with the background tracer concentration and tracer film thickness is discussed. An Arrhenius fit of the Mg self-diffusion data obtained using the low-temperature SIMS measurements from this study and the high-temperature radiotracer measurements of Shewmon and Rhines (1954) was found to be a good representation of both types of diffusion data that cover a broad range of temperatures between 250 - 627° C (523 900 K).

  2. Overview of SIMS-Based Experimental Studies of Tracer Diffusion in Solids and Application to Mg Self-Diffusion

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

    Kulkarni, Nagraj S.; Bruce Warmack, Robert J.; Radhakrishnan, Bala; Hunter, Jerry L.; Sohn, Yongho; Coffey, Kevin R.; Murch, Graeme E.; Belova, Irina V.

    2014-09-23

    Tracer diffusivities provide the most fundamental information on diffusion in materials and are the foundation of robust diffusion databases. Compared to traditional radiotracer techniques that utilize radioactive isotopes, the secondary ion mass spectrometry (SIMS) based thin-film technique for tracer diffusion is based on the use of enriched stable isotopes that can be accurately profiled using SIMS. Experimental procedures & techniques that are utilized for the measurement of tracer diffusion coefficients are presented for pure magnesium, which presents some unique challenges due to the ease of oxidation. The development of a modified Shewmon-Rhines diffusion capsule for annealing Mg and an ultra-highmore » vacuum (UHV) system for sputter deposition of Mg isotopes are discussed. Optimized conditions for accurate SIMS depth profiling in polycrystalline Mg are provided. An automated procedure for the correction of heat-up and cool-down times during tracer diffusion annealing is discussed. The non-linear fitting of a SIMS depth profile data using the thin film Gaussian solution to obtain the tracer diffusivity along with the background tracer concentration and tracer film thickness is discussed. An Arrhenius fit of the Mg self-diffusion data obtained using the low-temperature SIMS measurements from this study and the high-temperature radiotracer measurements of Shewmon and Rhines (1954) was found to be a good representation of both types of diffusion data that cover a broad range of temperatures between 250 - 627° C (523 900 K).« less

  3. Narrow groove welding gas diffuser assembly and welding torch

    DOE Patents [OSTI]

    Rooney, Stephen J.

    2001-01-01

    A diffuser assembly is provided for narrow groove welding using an automatic gas tungsten arc welding torch. The diffuser assembly includes a manifold adapted for adjustable mounting on the welding torch which is received in a central opening in the manifold. Laterally extending manifold sections communicate with a shield gas inlet such that shield gas supplied to the inlet passes to gas passages of the manifold sections. First and second tapered diffusers are respectively connected to the manifold sections in fluid communication with the gas passages thereof. The diffusers extend downwardly along the torch electrode on opposite sides thereof so as to release shield gas along the length of the electrode and at the distal tip of the electrode. The diffusers are of a transverse width which is on the order of the thickness of the electrode so that the diffusers can, in use, be inserted into a narrow welding groove before and after the electrode in the direction of the weld operation.

  4. Fracture-Flow-Enhanced Solute Diffusion into Fractured Rock

    SciTech Connect (OSTI)

    Wu, Yu-Shu; Ye, Ming; Sudicky, E.A.

    2007-12-15

    We propose a new conceptual model of fracture-flow-enhanced matrix diffusion, which correlates with fracture-flow velocity, i.e., matrix diffusion enhancement induced by rapid fluid flow within fractures. According to the boundary-layer or film theory, fracture flow enhanced matrix diffusion may dominate mass-transfer processes at fracture-matrix interfaces, because rapid flow along fractures results in large velocity and concentration gradients at and near fracture-matrix interfaces, enhancing matrix diffusion at matrix surfaces. In this paper, we present a new formulation of the conceptual model for enhanced fracture-matrix diffusion, and its implementation is discussed using existing analytical solutions and numerical models. In addition, we use the enhanced matrix diffusion concept to analyze laboratory experimental results from nonreactive and reactive tracer breakthrough tests, in an effort to validate the new conceptual model.

  5. Diffusion of n-type dopants in germanium

    SciTech Connect (OSTI)

    Chroneos, A.; Bracht, H.

    2014-03-15

    Germanium is being actively considered by the semiconductor community as a mainstream material for nanoelectronic applications. Germanium has advantageous materials properties; however, its dopant-defect interactions are less understood as compared to the mainstream material, silicon. The understanding of self- and dopant diffusion is essential to form well defined doped regions. Although p-type dopants such as boron exhibit limited diffusion, n-type dopants such as phosphorous, arsenic, and antimony diffuse quickly via vacancy-mediated diffusion mechanisms. In the present review, we mainly focus on the impact of intrinsic defects on the diffusion mechanisms of donor atoms and point defect engineering strategies to restrain donor atom diffusion and to enhance their electrical activation.

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

    Office of Scientific and Technical Information (OSTI)

    NEUTRON IRRADIATION BEHAVIOR AT 80 DEG C Citation Details In-Document Search Title: CRYSTAL STRUCTURE OF OXIDES AND THEIR NEUTRON IRRADIATION BEHAVIOR AT 80 DEG C (in French) ...

  9. Estimating emissions of 20 VOCs. 2: Diffused aeration (Journal Article) |

    Office of Scientific and Technical Information (OSTI)

    SciTech Connect Estimating emissions of 20 VOCs. 2: Diffused aeration Citation Details In-Document Search Title: Estimating emissions of 20 VOCs. 2: Diffused aeration A relationship developed in a companion paper to estimate emissions from surface-aerated reactors that accounts for both gas- and liquid-phase mass-transfer resistances is extended to reactors with diffused-aeration systems. The method accurately predicts the observed stripping rate of 20 volatile organic compounds (VOCs) with

  10. Model-Independent Characterization of Charge Diffusion in Thick Fully

    Office of Scientific and Technical Information (OSTI)

    Depleted CCDs (Journal Article) | SciTech Connect Model-Independent Characterization of Charge Diffusion in Thick Fully Depleted CCDs Citation Details In-Document Search Title: Model-Independent Characterization of Charge Diffusion in Thick Fully Depleted CCDs We present a new method to measure charge diffusion in charge-coupled devices (CCDs). The method is based on a statistical characterization of the shapes of charge clouds produced by low-energy X-rays using known properties of the

  11. Control of light diffusion in a disordered photonic waveguide

    SciTech Connect (OSTI)

    Sarma, Raktim; Cao, Hui; Golubev, Timofey; Yamilov, Alexey

    2014-07-28

    We control the diffusion of light in a disordered photonic waveguide by modulating the waveguide geometry. In a single waveguide of varying cross-section, the diffusion coefficient changes spatially in two dimensions due to localization effects. The intensity distribution inside the waveguide agrees with the prediction of the self-consistent theory of localization. Our work shows that wave diffusion can be efficiently manipulated without modifying the structural disorder.

  12. Spectral Components Analysis of Diffuse Emission Processes (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Journal Article: Spectral Components Analysis of Diffuse Emission Processes Citation Details In-Document Search Title: Spectral Components Analysis of Diffuse Emission Processes We develop a novel method to separate the components of a diffuse emission process based on an association with the energy spectra. Most of the existing methods use some information about the spatial distribution of components, e.g., closeness to an external template, independence of

  13. DOE Issues Final Request for Proposal for Portsmouth Gaseous Diffusion

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

    Plant Support Services | Department of Energy Portsmouth Gaseous Diffusion Plant Support Services DOE Issues Final Request for Proposal for Portsmouth Gaseous Diffusion Plant Support Services December 9, 2014 - 3:37pm Addthis Media Contact Lynette Chafin, 513-246-0461, Lynette.Chafin@emcbc.doe.gov Cincinnati -- The U.S. Department of Energy today issued a Final Request for Proposal (RFP), for the continued performance of infrastructure support services at the Portsmouth Gaseous Diffusion

  14. DOE Seeks Deactivation Contractor for Paducah Gaseous Diffusion Plant |

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

    Department of Energy Deactivation Contractor for Paducah Gaseous Diffusion Plant DOE Seeks Deactivation Contractor for Paducah Gaseous Diffusion Plant August 9, 2013 - 5:30pm Addthis Media Contact Bill Taylor, 803-952-8564 bill.taylor@srs.gov Cincinnati - The U.S. Department of Energy (DOE) today issued a Request for Task Proposal (RTP) for deactivation activities at the Paducah Gaseous Diffusion Plant (GDP) in Paducah, Kentucky. These services are required so that DOE can address the return

  15. DOE Seeks Proposals for Portsmouth Gaseous Diffusion Plant Technical

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

    Services Contract | Department of Energy Proposals for Portsmouth Gaseous Diffusion Plant Technical Services Contract DOE Seeks Proposals for Portsmouth Gaseous Diffusion Plant Technical Services Contract June 19, 2012 - 12:00pm Addthis Media Contact Bill Taylor bill.taylor@srs.gov 803-952-8564 Cincinnati - The Department of Energy today issued a Draft Request for Proposals (RFP) for an Environmental Technical Services acquisition at the Portsmouth Gaseous Diffusion Plant near Piketon, Ohio.

  16. FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION

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

    STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) | Department of Energy FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION AND DIFFUSION STUDIES II - STATE ENERGY STRATEGIES (SEEDSII-SES) FUNDING OPPORTUNITY ANNOUNCEMENT: SOLAR ENERGY EVOLUTION

  17. Paducah Gaseous Diffusion Plant Transition | Department of Energy

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

    Gaseous Diffusion Plant Transition Paducah Gaseous Diffusion Plant Transition GDP Shutdown Paducah site_map-USEC_lease.jpg The Energy Policy Act of 1992 transferred operational responsibility for the site's uranium enrichment operations to the United States Enrichment Corporation (USEC), originally a government corporation that became a publicly held company in 1998. USEC assumed responsibility for enrichment operations at the Paducah Gaseous Diffusion Plant (GDP) and leased property from DOE.

  18. DOE - Office of Legacy Management -- Portsmouth Gaseous Diffusion Plant -

    Office of Legacy Management (LM)

    026 Portsmouth Gaseous Diffusion Plant - 026 FUSRAP Considered Sites Site: Portsmouth Gaseous Diffusion Plant (026 ) Designated Name: Alternate Name: Location: Evaluation Year: Site Operations: Site Disposition: Radioactive Materials Handled: Primary Radioactive Materials Handled: Radiological Survey(s): Site Status: The Portsmouth Gaseous Diffusion Plant (PGDP) is located in south central Ohio, approximately 20 miles north of Portsmouth, Ohio and 70 miles south of Columbus, Ohio.

  19. Paducah Gaseous Diffusion Plant - GW OU Northwest Plume | Department of

    Office of Environmental Management (EM)

    Energy Gaseous Diffusion Plant - GW OU Northwest Plume Paducah Gaseous Diffusion Plant - GW OU Northwest Plume January 1, 2014 - 12:00pm Addthis US Department of Energy Groundwater Database Groundwater Master Report InstallationName, State: Paducah Gaseous Diffusion Plant, KY Responsible DOE Office: Office of Environmental Management Plume Name: GW OU Northwest Plume Remediation Contractor: LATA Environmental Services of Kentucky, LLC PBS Number: PA-0040 Report Last Updated: 2014

  20. Transport diffusion of liquid water and methanol through membranes (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Transport diffusion of liquid water and methanol through membranes Citation Details In-Document Search Title: Transport diffusion of liquid water and methanol through membranes The authors carried out dual-control-volume grand canonical molecular dynamics simulations of the transport diffusion of liquid water and methanol to vacuum under a fixed chemical potential gradient through a slit pore consisting of Au(111) surfaces covered by -CH{sub 3} and -OH terminated

  1. ARM - Datastreams - skyrad60s

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

    skyrad60s Archive Data Plot Example skyrad60s Archive Data Plot Datastream : SKYRAD60S Sky radiation sensor: 60-second downwelling irradiances Active Dates 1996.10.09 -...

  2. Measurement of thermal conductivity in proton irradiated silicon (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Measurement of thermal conductivity in proton irradiated silicon Citation Details In-Document Search Title: Measurement of thermal conductivity in proton irradiated silicon 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

  3. 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

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

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Design of a Compact Fatigue Tester for Testing Irradiated Materials Citation Details In-Document Search Title: Design of a Compact Fatigue Tester for Testing Irradiated Materials A compact fatigue testing machine that can be easily inserted into 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 has been carefully considered by

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

    Office of Scientific and Technical Information (OSTI)

    (BER) Country of Publication: United States Availability: ORNL Language: English Subject: 54 Environmental Sciences Longwave broadband upwelling irradiance; Longwave narrowband ...

  6. Adsorption and diffusion in zeolites: the pitfall of isotypic...

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

    Adsorption and diffusion in zeolites: the pitfall of isotypic crystal structures Previous Next List Nils E.R. Zimmermann, Maciej Haranczyk, Manju Sharma, Bei Liu, Berend Smit &...

  7. Adsorption and diffusion of Ru adatoms on Ru(0001)-supported...

    Office of Scientific and Technical Information (OSTI)

    Accepted Manuscript: Adsorption and diffusion of Ru adatoms on Ru(0001)-supported graphene: Large-scale first-principles calculations This content will become publicly available on...

  8. Intensity Pattern of Diffuse X-Ray Scattering From Thermally...

    Office of Scientific and Technical Information (OSTI)

    Intensity Pattern of Diffuse X-Ray Scattering From Thermally Populated Phonons in Fcc ... Sponsoring Org: DOE - BASIC ENERGY SCIENCESUNIVERSITY Country of Publication: United ...

  9. Manhattan Project: The Navy and Thermal Diffusion, 1944

    Office of Scientific and Technical Information (OSTI)

    Diffusion columns, S-50 Thermal Diffusion Plant, Oak Ridge, 1945. THE NAVY AND THERMAL DIFFUSION (Oak Ridge: Clinton, 1944) Events > The Uranium Path to the Bomb, 1942-1944 Y-12: Design, 1942-1943 Y-12: Construction, 1943 Y-12: Operation, 1943-1944 Working K-25 into the Mix, 1943-1944 The Navy and Thermal Diffusion, 1944 As problems with both Y-12 and K-25 reached crisis proportions in spring and summer 1944, the Manhattan Project received help from an unexpected source: the United States

  10. Low cost fuel cell diffusion layer configured for optimized anode...

    Office of Scientific and Technical Information (OSTI)

    for optimized anode water management Citation Details In-Document Search Title: Low cost fuel cell diffusion layer configured for optimized anode water management A fuel cell ...

  11. Uranium and Strontium Batch Sorption and Diffusion Kinetics into...

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

    Uranium and Strontium Batch Sorption and Diffusion Kinetics into Mesoporous Silica Friday, February 27, 2015 Figure 1 Figure 1. Transmission electron microscopy images of (A)...

  12. The Digital Road to Scientific Knowledge Diffusion; A Faster...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: The Digital Road to Scientific Knowledge Diffusion; A Faster, Better Way to Scientific Progress? Citation Details In-Document Search Title: The Digital Road to ...

  13. Lithium Ion Solvation and Diffusion in Bulk Organic Electrolytes...

    Office of Scientific and Technical Information (OSTI)

    in Bulk Organic Electrolytes from First Principles Molecular Dynamics Citation Details In-Document Search Title: Lithium Ion Solvation and Diffusion in Bulk Organic ...

  14. FLAMMABLE GAS DIFFUSION THROUGH SINGLE SHELL TANK (SST) DOMES

    SciTech Connect (OSTI)

    MEACHAM, J.E.

    2003-11-10

    This report quantified potential hydrogen diffusion through Hanford Site Single-Shell tank (SST) domes if the SSTs were hypothetically sealed airtight. Results showed that diffusion would keep headspace flammable gas concentrations below the lower flammability limit in the 241-AX and 241-SX SST. The purpose of this document is to quantify the amount of hydrogen that could diffuse through the domes of the SSTs if they were hypothetically sealed airtight. Diffusion is assumed to be the only mechanism available to reduce flammable gas concentrations. The scope of this report is limited to the 149 SSTs.

  15. Experiments on a ceramic electrolysis cell and a palladium diffuser...

    Office of Scientific and Technical Information (OSTI)

    on a ceramic electrolysis cell and a palladium diffuser at the tritium systems test assembly Citation Details In-Document Search Title: Experiments on a ceramic...

  16. Diffusion in confinement: kinetic simulations of self- and collective...

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

    confinement: kinetic simulations of self- and collective diffusion behavior of adsorbed gases Previous Next List M. K. F. Abouelnasr and B. Smit, PCCP 14 (33), 11600 (2012) DOI:...

  17. Vapor Barriers or Vapor Diffusion Retarders | Department of Energy

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

    called "structural" vapor diffusion retarders. Materials such as rigid foam insulation, reinforced plastics, aluminum, and stainless steel are relatively resistant to...

  18. Extracting the diffusion tensor from molecular dynamics simulation with Milestoning

    SciTech Connect (OSTI)

    Mugnai, Mauro L.; Elber, Ron

    2015-01-07

    We propose an algorithm to extract the diffusion tensor from Molecular Dynamics simulations with Milestoning. A Kramers-Moyal expansion of a discrete master equation, which is the Markovian limit of the Milestoning theory, determines the diffusion tensor. To test the algorithm, we analyze overdamped Langevin trajectories and recover a multidimensional Fokker-Planck equation. The recovery process determines the flux through a mesh and estimates local kinetic parameters. Rate coefficients are converted to the derivatives of the potential of mean force and to coordinate dependent diffusion tensor. We illustrate the computation on simple models and on an atomically detailed system—the diffusion along the backbone torsions of a solvated alanine dipeptide.

  19. Continuous Flow Diffusion Chamber Measurements of IN Concentration

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

    Flow Diffusion Chamber (CFDC) Measurements of IN Concentration Concentrations of Ice-Nucleating Aerosol (IN) as a function of Temperature and %Supersaturation Sarah Brooks and...

  20. Paducah Gaseous Diffusion Plant - GW OU Northeast Plume | Department...

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

    Paducah Gaseous Diffusion Plant - GW OU Northeast Plume January 1, 2014 - 12:00pm Addthis US Department of Energy Groundwater Database Groundwater Master Report InstallationName, ...

  1. Paducah Gaseous Diffusion Plant Draft Paducah Environmental Assessment...

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

    Draft Environmental Assessment (EA) for Potential Land and Facilities Transfers at the Paducah Gaseous Diffusion Plant in McCracken County, Kentucky. DOE is inviting comments on...

  2. Binary and ternary gas mixtures with temperature enhanced diffuse...

    Office of Scientific and Technical Information (OSTI)

    Binary and ternary gas mixtures with temperature enhanced diffuse glow discharge characteristics for use in closing switches Title: Binary and ternary gas mixtures with temperature ...

  3. Diffusion coefficient of three-dimensional Yukawa liquids

    SciTech Connect (OSTI)

    Dzhumagulova, K. N.; Ramazanov, T. S.; Masheeva, R. U.

    2013-11-15

    The purpose of this work is an investigation of the diffusion coefficient of the dust component in complex plasma. The computer simulation of the Yukawa liquids was made on the basis of the Langevin equation, which takes into account the influence of buffer plasma on the dust particles dynamics. The GreenKubo relation was used to calculate the diffusion coefficient. Calculations of the diffusion coefficient for a wide range of the system parameters were performed. Using obtained numerical data, we constructed the interpolation formula for the diffusion coefficient. We also show that the interpolation formula correctly describes experimental data obtained under microgravity conditions.

  4. Covariant functional diffusion equation for Polyakov's bosonic string

    SciTech Connect (OSTI)

    Botelho, L. C. L.

    1989-07-15

    I write a covariant functional diffusion equation for Polyakov's bosonic string with the string's world-sheet area playing the role of proper time.

  5. Lithium Ion Solvation and Diffusion in Bulk Organic Electrolytes...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Lithium Ion Solvation and Diffusion in Bulk Organic Electrolytes from First Principles and ... Resource Relation: Journal Name: Journal of Physical Chemistry B, vol. ...

  6. Optical processing furnace with quartz muffle and diffuser plate

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1995-01-01

    An optical furnace for annealing a process wafer comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the door or wall of the muffle is also provided for controlling the source of optical energy. The quartz for the diffuser plate is surface etched (to give the quartz diffusive qualities) in the furnace during a high intensity burn-in process.

  7. Modeling heat conduction and radiation transport with the diffusion...

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

    heat conduction and radiation transport with the diffusion equation in NIF ALE-AMR This ... Home Search Collections Journals About Contact us My IOPscience Modeling Heat Conduction ...

  8. Strain effect on the adsorption, diffusion, and molecular dissociation...

    Office of Scientific and Technical Information (OSTI)

    Strain effect on the adsorption, diffusion, and molecular dissociation of hydrogen on Mg (0001) surface Citation Details In-Document Search Title: Strain effect on the adsorption,...

  9. HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid Architectures

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

    fidelity simulation of a diverse range of kinetic systems. Available for thumbnail of Feynman Center (505) 665-9090 Email HILO: Quasi Diffusion Accelerated Monte Carlo on Hybrid...

  10. A coupling strategy for nonlocal and local diffusion models with...

    Office of Scientific and Technical Information (OSTI)

    Subject: 97 MATHEMATICS AND COMPUTING nonlocal models; coupling method; optimization; nonlocal vector calculus; mixed boundary conditions; nonlocal diffusion Word Cloud More Like ...

  11. The influence of clouds and diffuse radiation on ecosystem-atmosphere CO2 and CO18O exhanges

    SciTech Connect (OSTI)

    Still, C.J.; Riley, W.J.; Biraud, S.C.; Noone, D.C.; Buenning, N.H.; Randerson, J.T.; Torn, M.S.; Welker, J.; White, J.W.C.; Vachon, R.; Farquhar, G.D.; Berry, J.A.

    2009-05-01

    This study evaluates the potential impact of clouds on ecosystem CO{sub 2} and CO{sub 2} isotope fluxes ('isofluxes') in two contrasting ecosystems (a broadleaf deciduous forest and a C{sub 4} grassland), in a region for which cloud cover, meteorological, and isotope data are available for driving the isotope-enabled land surface model, ISOLSM. Our model results indicate a large impact of clouds on ecosystem CO{sub 2} fluxes and isofluxes. Despite lower irradiance on partly cloudy and cloudy days, predicted forest canopy photosynthesis was substantially higher than on clear, sunny days, and the highest carbon uptake was achieved on the cloudiest day. This effect was driven by a large increase in light-limited shade leaf photosynthesis following an increase in the diffuse fraction of irradiance. Photosynthetic isofluxes, by contrast, were largest on partly cloudy days, as leaf water isotopic composition was only slightly depleted and photosynthesis was enhanced, as compared to adjacent clear sky days. On the cloudiest day, the forest exhibited intermediate isofluxes: although photosynthesis was highest on this day, leaf-to-atmosphere isofluxes were reduced from a feedback of transpiration on canopy relative humidity and leaf water. Photosynthesis and isofluxes were both reduced in the C{sub 4} grass canopy with increasing cloud cover and diffuse fraction as a result of near-constant light limitation of photosynthesis. These results suggest that some of the unexplained variation in global mean {delta}{sup 18}O of CO{sub 2} may be driven by large-scale changes in clouds and aerosols and their impacts on diffuse radiation, photosynthesis, and relative humidity.

  12. 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.

  13. 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.

  14. Low cost fuel cell diffusion layer configured for optimized anode water management

    DOE Patents [OSTI]

    Owejan, Jon P; Nicotera, Paul D; Mench, Matthew M; Evans, Robert E

    2013-08-27

    A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel is higher than the diffusion resistance of the cathode gas diffusion layer. The anode gas diffusion layer may comprise filler particles having in-plane platelet geometries and be made of lower cost materials and manufacturing processes than currently available commercial carbon fiber substrates. The diffusion resistance difference between the anode gas diffusion layer and the cathode gas diffusion layer may allow for passive water balance control.

  15. Comparison of silver, cesium, and strontium release predictions using PARFUME with results from the AGR-1 irradiation experiment

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

    Collin, Blaise P.; Petti, David A.; Demkowicz, Paul A.; Maki, John T.

    2015-08-22

    The PARFUME (PARticle FUel ModEl) code was used to predict the release of fission products silver, cesium, and strontium from tristructural isotropic coated fuel particles and compacts during the first irradiation experiment (AGR-1) of the Advanced Gas Reactor Fuel Development and Qualification program. The PARFUME model for the AGR-1 experiment used the fuel compact volume average temperature for each of the 620 days of irradiation to calculate the release of silver, cesium, and strontium from a representative particle for a select number of AGR-1 compacts. Post-irradiation examination measurements provided data on release of these fission products from fuel compacts andmore » fuel particles, and retention of silver in the compacts outside of the silicon carbide (SiC) layer. PARFUME-predicted fractional release of silver, cesium, and strontium was determined and compared to the PIE measurements. For silver, comparisons show a trend of over-prediction at low burnup and under-prediction at high burnup. PARFUME has limitations in the modeling of the temporal and spatial distributions of the temperature and burnup across the compacts, which affects the accuracy of its predictions. Nevertheless, the comparisons on silver release lie in the same order of magnitude. Results show an overall over-prediction of the fractional release of cesium by PARFUME. For particles with failed SiC layers, the over-prediction is by a factor of up to 3, corresponding to a potential over-estimation of the diffusivity in uranium oxycarbide (UCO) by a factor of up to 250. For intact particles, whose release is much lower, the over-prediction is by a factor of up to 100, which could be attributed to an over-estimated diffusivity in SiC by about 40% on average. The release of strontium from intact particles is also over-predicted by PARFUME, which also points towards an over-estimated diffusivity of strontium in either SiC or UCO, or possibly both. The measured strontium fractional release from intact particles varied considerably from compact to compact, making it difficult to assess the effective over-estimation of the diffusivities. Moreover, the release of strontium from particles with failed SiC is difficult to observe experimentally due to the release from intact particles, preventing any conclusions to be made on the accuracy or validity of the PARFUME predictions and the modeled diffusivity of strontium in UCO.« less

  16. 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 are unknown, a sensitivity analysis must be carried out to provide lower and upper bounds of the material behaviour. Finally, the model can be used as a basis to formulate a macroscopic material model for concrete subject to irradiation, which later can be used in structural analyses to estimate the structural impact of irradiation on nuclear power plants.

  17. Uranium and cesium diffusion in fuel cladding of electrogenerating channel

    SciTech Connect (OSTI)

    Vasilev, I. V. Ivanov, A. S.; Churin, V. A.

    2014-12-15

    The results of reactor tests of a carbonitride fuel in a single-crystal cladding from a molybdenum-based alloy can be used in substantiating the operational reliability of fuels in developing a project of a megawatt space nuclear power plant. The results of experimental studies of uranium and cesium penetration into the single-crystal cladding of fuel elements with a carbonitride fuel are interpreted. Those fuel elements passed nuclear power tests in the Ya-82 pilot plant for 8300 h at a temperature of about 1500C. It is shown that the diffusion coefficients for uranium diffusion into the cladding are virtually coincident with the diffusion coefficients measured earlier for uranium diffusion into polycrystalline molybdenum. It is found that the penetration of uranium into the cladding is likely to occur only in the case of a direct contact between the cladding and fuel. The experimentally observed nonmonotonic uranium-concentration profiles are explained in terms of predominant uranium diffusion along grain boundaries. It is shown that a substantially nonmonotonic behavior observed in our experiment for the uranium-concentration profile may be explained by the presence of a polycrystalline structure of the cladding in the surface region from its inner side. The diffusion coefficient is estimated for the grain-boundary diffusion of uranium. The diffusion coefficients for cesium are estimated on the basis of experimental data obtained in the present study.

  18. Optical processing furnace with quartz muffle and diffuser plate

    DOE Patents [OSTI]

    Sopori, Bhushan L.

    1996-01-01

    An optical furnace for annealing a process wafer comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the wall of the muffle is also provided for controlling the source of optical energy.

  19. 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.

  20. 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.

  1. SRS history and experience with palladium diffusers. Revision 1

    SciTech Connect (OSTI)

    Clark, E.A.; Dauchess, D.A.; Heung, L.K.; Rabun, R.L.; Motyka, T.

    1995-08-11

    The Savannah River Site (SRS) has processed tritium in support of national defense programs since 1955. Palladium diffusers have been used extensively for separating hydrogen isotopes from inert gases (such as argon, helium, and nitrogen). In almost forty years of service, the design of the diffuser has been steadily improving. Several diffuser designs from different manufacturers have been evaluated at SRS. The operating experience gained from these designs together with failure analyses performed on failed units have led to several recommendations for improved diffuser designs and operating methods. This experience gained at SRS and the following recommendations form the basis of this report. Even though palladium diffuser technology has proven to be reliable, SRS has examined several alternative technologies over the past several years. This report will also review some of these promising alternatives.

  2. Grain boundary and triple junction diffusion in nanocrystalline copper

    SciTech Connect (OSTI)

    Wegner, M. Leuthold, J.; Peterlechner, M.; Divinski, S. V.; Song, X.; Wilde, G.

    2014-09-07

    Grain boundary and triple junction diffusion in nanocrystalline Cu samples with grain sizes, ?d?, of ?35 and ?44?nm produced by spark plasma sintering were investigated by the radiotracer method using the {sup 63}Ni isotope. The measured diffusivities, D{sub eff}, are comparable with those determined previously for Ni grain boundary diffusion in well-annealed, high purity, coarse grained, polycrystalline copper, substantiating the absence of a grain size effect on the kinetic properties of grain boundaries in a nanocrystalline material at grain sizes d???35?nm. Simultaneously, the analysis predicts that if triple junction diffusion of Ni in Cu is enhanced with respect to the corresponding grain boundary diffusion rate, it is still less than 500?D{sub gb} within the temperature interval from 420?K to 470?K.

  3. Radon diffusion through multilayer earthen covers: models and simulations

    SciTech Connect (OSTI)

    Mayer, D.W.; Oster, C.A.; Nelson, R.W.; Gee, G.W.

    1981-09-01

    A capability to model and analyze the fundamental interactions that influence the diffusion of radon gas through uranium mill tailings and cover systems has been investigated. The purpose of this study is to develop the theoretical basis for modeling radon diffusion and to develop an understanding of the fundamental interactions that influence radon diffusion. This study develops the theoretical basis for modeling radon diffusion in one, two and three dimensions. The theory has been incorporated into three computer models that are used to analyze several tailings and cover configurations. This report contains a discussion of the theoretical basis for modeling radon diffusion, a discussion of the computer models used to analyze uranium mill tailings and multilayered cover systems, and presents the results that have been obtained.

  4. Mechanisms of Stochastic Diffusion of Energetic Ions in Spherical Tori

    SciTech Connect (OSTI)

    Ya.I. Kolesnichenko; R.B. White; Yu.V. Yakovenko

    2001-01-18

    Stochastic diffusion of the energetic ions in spherical tori is considered. The following issues are addressed: (I) Goldston-White-Boozer diffusion in a rippled field; (ii) cyclotron-resonance-induced diffusion caused by the ripple; (iii) effects of non-conservation of the magnetic moment in an axisymmetric field. It is found that the stochastic diffusion in spherical tori with a weak magnetic field has a number of peculiarities in comparison with conventional tokamaks; in particular, it is characterized by an increased role of mechanisms associated with non-conservation of the particle magnetic moment. It is concluded that in current experiments on National Spherical Torus eXperiment (NSTX) the stochastic diffusion does not have a considerable influence on the confinement of energetic ions.

  5. 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.

  6. Irreversible reactions and diffusive escape: Stationary properties

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

    Krapivsky, Paul L.; Ben-Naim, Eli

    2015-05-01

    We study three basic diffusion-controlled reaction processes—annihilation, coalescence, and aggregation. We examine the evolution starting with the most natural inhomogeneous initial configuration where a half-line is uniformly filled by particles, while the complementary half-line is empty. We show that the total number of particles that infiltrate the initially empty half-line is finite and has a stationary distribution. We determine the evolution of the average density from which we derive the average total number N of particles in the initially empty half-line; e.g. for annihilationmore » $$\\langle N\\rangle = \\frac{3}{16}+\\frac{1}{4\\π}$$ . For the coalescence process, we devise a procedure that in principle allows one to compute P(N), the probability to find exactly N particles in the initially empty half-line; we complete the calculations in the first non-trivial case (N = 1). As a by-product we derive the distance distribution between the two leading particles.« less

  7. Thick diffusion limit boundary layer test problems

    SciTech Connect (OSTI)

    Bailey, T. S.; Warsa, J. S.; Chang, J. H.; Adams, M. L.

    2013-07-01

    We develop two simple test problems that quantify the behavior of computational transport solutions in the presence of boundary layers that are not resolved by the spatial grid. In particular we study the quantitative effects of 'contamination' terms that, according to previous asymptotic analyses, may have a detrimental effect on the solutions obtained by both discontinuous finite element (DFEM) and characteristic-method (CM) spatial discretizations, at least for boundary layers caused by azimuthally asymmetric incident intensities. Few numerical results have illustrated the effects of this contamination, and none have quantified it to our knowledge. Our test problems use leading-order analytic solutions that should be equal to zero in the problem interior, which means the observed interior solution is the error introduced by the contamination terms. Results from DFEM solutions demonstrate that the contamination terms can cause error propagation into the problem interior for both orthogonal and non-orthogonal grids, and that this error is much worse for non-orthogonal grids. This behavior is consistent with the predictions of previous analyses. We conclude that these boundary layer test problems and their variants are useful tools for the study of errors that are introduced by unresolved boundary layers in diffusive transport problems. (authors)

  8. DIFFUSIVE SHOCK ACCELERATION SIMULATIONS OF RADIO RELICS

    SciTech Connect (OSTI)

    Kang, Hyesung; Ryu, Dongsu; Jones, T. W. E-mail: ryu@canopus.cnu.ac.kr

    2012-09-01

    Recent radio observations have identified a class of structures, so-called radio relics, in clusters of galaxies. The radio emission from these sources is interpreted as synchrotron radiation from GeV electrons gyrating in {mu}G-level magnetic fields. Radio relics, located mostly in the outskirts of clusters, seem to associate with shock waves, especially those developed during mergers. In fact, they seem to be good structures to identify and probe such shocks in intracluster media (ICMs), provided we understand the electron acceleration and re-acceleration at those shocks. In this paper, we describe time-dependent simulations for diffusive shock acceleration at weak shocks that are expected to be found in ICMs. Freshly injected as well as pre-existing populations of cosmic-ray (CR) electrons are considered, and energy losses via synchrotron and inverse Compton are included. We then compare the synchrotron flux and spectral distributions estimated from the simulations with those in two well-observed radio relics in CIZA J2242.8+5301 and ZwCl0008.8+5215. Considering that CR electron injection is expected to be rather inefficient at weak shocks with Mach number M {approx}< a few, the existence of radio relics could indicate the pre-existing population of low-energy CR electrons in ICMs. The implication of our results on the merger shock scenario of radio relics is discussed.

  9. Cell Simulation Package for Reactions and Diffusion

    Energy Science and Technology Software Center (OSTI)

    2005-04-01

    ChemCell is a simulation package designed for modeling signalling, regulatory, and metabolic pathways in biological cells. It reads input flies that describe the geomeby of the cell and positions of particles that represent proteins, protein complexes, and other bio-molecules. It also reads in lists of reactions and associated rates and other boundary condition information. ChemCell then models the reaction and diffusion of these particles within the cellular geometry as they interact overtime. It produces statisticalmore » information about the state of the cell, as well as snapshots of the reaction network. We anticipate ChemCell will be useful to researchers who wish to perform spatio-temporal modeling of cellular processes and who wish to develop new models or algorithms to add to the code. Thus ChemCell is also designed to be easy to modify and extend. The ChemCell package includes auxiliary codes for setting up problems and analyzing output.« less

  10. 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.

  11. 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 international intercomparisons among NMIs. Ultimately, the spectral irradiance can be realized with expanded measurement uncertainties of far less than 1 % over a wide spectral range. Thus, for customers with high demands on low measurement uncertainties, it is possible to calibrate their working standards directly against the blackbody-radiator, taking into account the higher necessary effort. In special cases it is possible to calibrate the customer's spectroradiometric facilities directly in front of the blackbody-radiator. In the context of the European Metrology Research Project Traceability for surface spectral solar ultraviolet radiation, the traceability chain will be improved and adapted.

  12. Diffusion Barrier Selection from Refractory Metals (Zr, Mo and Nb) via Interdiffusion Investigation for U-Mo RERTR Fuel Alloy

    SciTech Connect (OSTI)

    K. Huang; C. Kammerer; D. D. Keiser, Jr.; Y. H. Sohn

    2014-04-01

    U-Mo alloys are being developed as low enrichment monolithic fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) Program. Diffusional interactions between the U-Mo fuel alloy and Al-alloy cladding within the monolithic fuel plate construct necessitate incorporation of a barrier layer. Fundamentally, a diffusion barrier candidate must have good thermal conductivity, high melting point, minimal metallurgical interaction, and good irradiation performance. Refractory metals, Zr, Mo, and Nb are considered based on their physical properties, and the diffusion behavior must be carefully examined first with U-Mo fuel alloy. Solid-to-solid U-10wt.%Mo vs. Mo, Zr, or Nb diffusion couples were assembled and annealed at 600, 700, 800, 900 and 1000 degrees C for various times. The interdiffusion microstructures and chemical composition were examined via scanning electron microscopy and electron probe microanalysis, respectively. For all three systems, the growth rate of interdiffusion zone were calculated at 1000, 900 and 800 degrees C under the assumption of parabolic growth, and calculated for lower temperature of 700, 600 and 500 degrees C according to Arrhenius relationship. The growth rate was determined to be about 10 3 times slower for Zr, 10 5 times slower for Mo and 10 6 times slower for Nb, than the growth rates reported for the interaction between the U-Mo fuel alloy and pure Al or Al-Si cladding alloys. Zr, however was selected as the barrier metal due to a concern for thermo- mechanical behavior of UMo/Nb interface observed from diffusion couples, and for ductile-to-brittle transition of Mo near room temperature.

  13. Nanocrystalline SiC and Ti3SiC2 Alloys for Reactor Materials: Diffusion of Fission Product Surrogates

    SciTech Connect (OSTI)

    Henager, Charles H.; Jiang, Weilin

    2014-11-01

    MAX phases, such as titanium silicon carbide (Ti3SiC2), have a unique combination of both metallic and ceramic properties, which make them attractive for potential nuclear applications. Ti3SiC2 has been suggested in the literature as a possible fuel cladding material. Prior to the application, it is necessary to investigate diffusivities of fission products in the ternary compound at elevated temperatures. This study attempts to obtain relevant data and make an initial assessment for Ti3SiC2. Ion implantation was used to introduce fission product surrogates (Ag and Cs) and a noble metal (Au) in Ti3SiC2, SiC, and a dual-phase nanocomposite of Ti3SiC2/SiC synthesized at PNNL. Thermal annealing and in-situ Rutherford backscattering spectrometry (RBS) were employed to study the diffusivity of the various implanted species in the materials. In-situ RBS study of Ti3SiC2 implanted with Au ions at various temperatures was also performed. The experimental results indicate that the implanted Ag in SiC is immobile up to the highest temperature (1273 K) applied in this study; in contrast, significant out-diffusion of both Ag and Au in MAX phase Ti3SiC2 occurs during ion implantation at 873 K. Cs in Ti3SiC2 is found to diffuse during post-irradiation annealing at 973 K, and noticeable Cs release from the sample is observed. This study may suggest caution in using Ti3SiC2 as a fuel cladding material for advanced nuclear reactors operating at very high temperatures. Further studies of the related materials are recommended.

  14. X-Ray Energy Responses of Silicon Tomography Detectors Irradiated with Fusion Produced Neutrons

    SciTech Connect (OSTI)

    Kohagura, J. [Plasma Research Centre, University of Tsukuba (Japan); Cho, T. [Plasma Research Centre, University of Tsukuba (Japan); Hirata, M. [Plasma Research Centre, University of Tsukuba (Japan); Numakura, T. [Plasma Research Centre, University of Tsukuba (Japan); Yokoyama, N. [Plasma Research Centre, University of Tsukuba (Japan); Fukai, T. [Plasma Research Centre, University of Tsukuba (Japan); Tomii, Y. [Plasma Research Centre, University of Tsukuba (Japan); Tokioka, S. [Plasma Research Centre, University of Tsukuba (Japan); Miyake, Y. [Plasma Research Centre, University of Tsukuba (Japan); Kiminami, S. [Plasma Research Centre, University of Tsukuba (Japan); Shimizu, K. [Plasma Research Centre, University of Tsukuba (Japan); Miyoshi, S. [Plasma Research Centre, University of Tsukuba (Japan); Hirano, K. [High Energy Accelerator Research Organization (Japan); Yoshida, M. [Japan Atomic Energy Research Institute (Japan); Yamauchi, M. [Japan Atomic Energy Research Institute (Japan); Kondoh, T. [Japan Atomic Energy Research Institute (Japan); Nishitani, T. [Japan Atomic Energy Research Institute (Japan)

    2005-01-15

    In order to clarify the effects of fusion-produced neutron irradiation on silicon semiconductor x-ray detectors, the x-ray energy responses of both n- and p-type silicon tomography detectors used in the Joint European Torus (JET) tokamak (n-type) and the GAMMA 10 tandem mirror (p-type) are studied using synchrotron radiation at the Photon Factory of the National Laboratory for High Energy Accelerator Research Organization (KEK). The fusion neutronics source (FNS) of Japan Atomic Energy Research Institute (JAERI) is employed as well-calibrated D-T neutron source with fluences from 10{sup 13} to 10{sup 15} neutrons/cm{sup 2} onto these semiconductor detectors. Different fluence dependence is found between these two types of detectors; that is, (i) for the n-type detector, the recovery of the degraded response is found after the neutron exposure beyond around 10{sup 13} neutrons/cm{sup 2} onto the detector. A further finding is followed as a 're-degradation' by a neutron irradiation level over about 10{sup 14} neutrons/cm{sup 2}. On the other hand, (ii) the energy response of the p-type detector shows only a gradual decrease with increasing neutron fluences. These properties are interpreted by our proposed theory on semiconductor x-ray responses in terms of the effects of neutrons on the effective doping concentration and the diffusion length of a semiconductor detector.

  15. 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.

  16. Dynamics and diffusion mechanism of low-density liquid silicon

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

    Shen, B.; Wang, Z. Y.; Dong, F.; Guo, Y. R.; Zhang, R. J.; Zheng, Y. X.; Wang, S. Y.; Wang, C. Z.; Ho, K. M.; Chen, L. Y.

    2015-11-05

    A first-order phase transition from a high-density liquid to a low-density liquid has been proposed to explain the various thermodynamic anomies of water. It also has been proposed that such liquid–liquid phase transition would exist in supercooled silicon. Computer simulation studies show that, across the transition, the diffusivity drops roughly 2 orders of magnitude, and the structures exhibit considerable tetrahedral ordering. The resulting phase is a highly viscous, low-density liquid silicon. Investigations on the atomic diffusion of such a novel form of liquid silicon are of high interest. Here we report such diffusion results from molecular dynamics simulations using themore » classical Stillinger–Weber (SW) potential of silicon. We show that the atomic diffusion of the low-density liquid is highly correlated with local tetrahedral geometries. We also show that atoms diffuse through hopping processes within short ranges, which gradually accumulate to an overall random motion for long ranges as in normal liquids. There is a close relationship between dynamical heterogeneity and hopping process. We point out that the above diffusion mechanism is closely related to the strong directional bonding nature of the distorted tetrahedral network. Here, our work offers new insights into the complex behavior of the highly viscous low density liquid silicon, suggesting similar diffusion behaviors in other tetrahedral coordinated liquids that exhibit liquid–liquid phase transition such as carbon and germanium.« less

  17. Dynamics and diffusion mechanism of low-density liquid silicon

    SciTech Connect (OSTI)

    Shen, B.; Wang, Z. Y.; Dong, F.; Guo, Y. R.; Zhang, R. J.; Zheng, Y. X.; Wang, S. Y.; Wang, C. Z.; Ho, K. M.; Chen, L. Y.

    2015-11-05

    A first-order phase transition from a high-density liquid to a low-density liquid has been proposed to explain the various thermodynamic anomies of water. It also has been proposed that such liquid–liquid phase transition would exist in supercooled silicon. Computer simulation studies show that, across the transition, the diffusivity drops roughly 2 orders of magnitude, and the structures exhibit considerable tetrahedral ordering. The resulting phase is a highly viscous, low-density liquid silicon. Investigations on the atomic diffusion of such a novel form of liquid silicon are of high interest. Here we report such diffusion results from molecular dynamics simulations using the classical Stillinger–Weber (SW) potential of silicon. We show that the atomic diffusion of the low-density liquid is highly correlated with local tetrahedral geometries. We also show that atoms diffuse through hopping processes within short ranges, which gradually accumulate to an overall random motion for long ranges as in normal liquids. There is a close relationship between dynamical heterogeneity and hopping process. We point out that the above diffusion mechanism is closely related to the strong directional bonding nature of the distorted tetrahedral network. Here, our work offers new insights into the complex behavior of the highly viscous low density liquid silicon, suggesting similar diffusion behaviors in other tetrahedral coordinated liquids that exhibit liquid–liquid phase transition such as carbon and germanium.

  18. Four-point Bend Testing of Irradiated Monolithic U-10Mo Fuel

    SciTech Connect (OSTI)

    Rabin, B. H.; Lloyd, W. R.; Schulthess, J. L.; Wright, J. K.; Lind, R. P.; Scott, L.; Wachs, K. M.

    2015-03-01

    This paper presents results of recently completed studies aimed at characterizing the mechanical properties of irradiated U-10Mo fuel in support of monolithic base fuel qualification. Mechanical properties were evaluated in four-point bending. Specimens were taken from fuel plates irradiated in the RERTR-12 and AFIP-6 Mk. II irradiation campaigns, and tests were conducted in the Hot Fuel Examination Facility (HFEF) at Idaho National Laboratory (INL). The monolithic fuel plates consist of a U-10Mo fuel meat covered with a Zr diffusion barrier layer fabricated by co-rolling, clad in 6061 Al using a hot isostatic press (HIP) bonding process. Specimens exhibited nominal (fresh) fuel meat thickness ranging from 0.25 mm to 0.64 mm, and fuel plate average burnup ranged from approximately 0.4 x 1021 fissions/cm3 to 6.0 x 1021 fissions/cm3. After sectioning the fuel plates, the 6061 Al cladding was removed by dissolution in concentrated NaOH. Pre- and post-dissolution dimensional inspections were conducted on test specimens to facilitate accurate analysis of bend test results. Four-point bend testing was conducted on the HFEF Remote Load Frame at a crosshead speed of 0.1 mm/min using custom-designed test fixtures and calibrated load cells. All specimens exhibited substantially linear elastic behavior and failed in a brittle manner. The influence of burnup on the observed slope of the stress-strain curve and the calculated fracture strength is discussed.

  19. Parallel computation safety analysis irradiation targets fission product molybdenum in neutronic aspect using the successive over-relaxation algorithm

    SciTech Connect (OSTI)

    Susmikanti, Mike; Dewayatna, Winter; Sulistyo, Yos

    2014-09-30

    One of the research activities in support of commercial radioisotope production program is a safety research on target FPM (Fission Product Molybdenum) irradiation. FPM targets form a tube made of stainless steel which contains nuclear-grade high-enrichment uranium. The FPM irradiation tube is intended to obtain fission products. Fission materials such as Mo{sup 99} used widely the form of kits in the medical world. The neutronics problem is solved using first-order perturbation theory derived from the diffusion equation for four groups. In contrast, Mo isotopes have longer half-lives, about 3 days (66 hours), so the delivery of radioisotopes to consumer centers and storage is possible though still limited. The production of this isotope potentially gives significant economic value. The criticality and flux in multigroup diffusion model was calculated for various irradiation positions and uranium contents. This model involves complex computation, with large and sparse matrix system. Several parallel algorithms have been developed for the sparse and large matrix solution. In this paper, a successive over-relaxation (SOR) algorithm was implemented for the calculation of reactivity coefficients which can be done in parallel. Previous works performed reactivity calculations serially with Gauss-Seidel iteratives. The parallel method can be used to solve multigroup diffusion equation system and calculate the criticality and reactivity coefficients. In this research a computer code was developed to exploit parallel processing to perform reactivity calculations which were to be used in safety analysis. The parallel processing in the multicore computer system allows the calculation to be performed more quickly. This code was applied for the safety limits calculation of irradiated FPM targets containing highly enriched uranium. The results of calculations neutron show that for uranium contents of 1.7676 g and 6.1866 g (× 10{sup 6} cm{sup −1}) in a tube, their delta reactivities are the still within safety limits; however, for 7.9542 g and 8.838 g (× 10{sup 6} cm{sup −1}) the limits were exceeded.

  20. Diffusion on (110) Surface of Molecular Crystal Pentaerythritol Tetranitrate

    SciTech Connect (OSTI)

    Wang, J; Golfinopoulos, T; Gee, R H; Huang, H

    2007-01-25

    Using classical molecular dynamics simulations, we investigate the diffusion mechanisms of admolecules on the (110) surface of molecular crystal pentaerythritol tetranitrate. Our results show that (1) admolecules are stable at off lattice sites, (2) admolecules diffuse along close-packed [1{bar 1}1] and [{bar 1}11] directions, and (3) admolecules detach from the surface at 350K and above. Based on the number of diffusion jumps as a function of temperature, we estimate the jump frequency to be v=1.14 x 10{sup 12} e{sup -0.08eV/kT} per second.

  1. Experimental Investigation of Radio-Turbulence Induced Diffusion -- Final Report

    SciTech Connect (OSTI)

    Spitz, H. B.; Usman, S.

    2005-07-07

    The outcome of this research project suggests that the transport of radon in water is significantly greater than that predicted solely by molecular diffusion. The original study was related to the long term storage of {sup 226}Ra-bearing sand at the DOE Fernald site and determining whether a barrier of water covering the sand would be effective in reducing the emanation of {sup 222}Rn from the sand. Initial observations before this study found the transport of radon in water to be greater than that predicted solely by molecular diffusion. Fick's law on diffusion was used to model the transport of radon in water including the impact associated with radioactive decay. Initial measurements suggested that the deposition of energy in water associated with the radioactive decay process influences diffusion and enhances transport of radon. A multi-region, one-dimensional, steady-state transport model was used to analyze the movement of radon through a sequential column of air, water and air. An effective diffusion coefficient was determined by varying the thickness of the water column and measuring the time for transport of {sup 222}Rn through of the water barrier. A one-region, one-dimensional transient diffusion equation was developed to investigate the build up of radon at the end of the water column to the time when a steady-state, equilibrium condition was achieved. This build up with time is characteristic of the transport rate of radon in water and established the basis for estimating the effective diffusion coefficient for {sup 222}Rn in water. Several experiments were conducted using different types and physical arrangements of water barriers to examine how radon transport is influenced by the water barrier. Results of our measurements confirm our theoretical analyses which suggest that convective forces other than pure molecular diffusion impact the transport of {sup 222}Rn through the water barrier. An effective diffusion coefficient is defined that includes effects of molecular diffusion and convection to describe the transport of radon in water. The effective diffusion coefficients measured in these experiments are 6.8 x 10{sup -4} {+-} 28% and 3.5 x 10{sup -4} {+-} 34% cm{sup 2} sec{sup -1} for the steady-state and transient diffusion conditions, respectively. Water barriers ranging in thickness from 30-50 cm reduce the amount of radon released from the radium-bearing source material by a factor of 0.3-0.1, respectively.

  2. DOE Announces Public Tours of Paducah Gaseous Diffusion Plant site |

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

    Department of Energy DOE Announces Public Tours of Paducah Gaseous Diffusion Plant site DOE Announces Public Tours of Paducah Gaseous Diffusion Plant site March 31, 2016 - 5:00pm Addthis PADUCAH, KY - The U.S. Department of Energy (DOE) has announced the opportunity for members of the community to participate in public tours of the Paducah Gaseous Diffusion Plant site starting monthly in April 2016. This will be the first time tours of the DOE site will be available to the public in its more

  3. Kinetic Isotopic Fractionation During Diffusion of Ionic Speciesin Water

    SciTech Connect (OSTI)

    Richter, Frank M.; Mendybaev, Ruslan A.; Christensen, John; Hutcheon, Ian D.; Williams, Ross W.; Sturchio, Neil C.; Beloso Jr.,Abelardo D.

    2005-06-09

    Experiments specifically designed to measure the ratio of the diffusivities of ions dissolved in water were used to determine D{sub Li}/D{sub K}, D{sub 7{sub Li}}/D{sub 6{sub Li}}, D{sub 25{sub Mg}}/D{sub 24{sub Mg}}, D{sub 26{sub Mg}}/D{sub 25{sub Mg}}, and D{sub 37{sub Cl}}/D{sub 35{sub Cl}}. The measured ratio of the diffusion coefficients for Li and K in water (D{sub Li}/D{sub K} = 0.6) is in good agreement with published data, providing evidence that the experimental design being used resolves the relative mobility of ions with adequate precision to also be used for determining the fractionation of isotopes by diffusion in water. In the case of Li we found measurable isotopic fractionation associated with the diffusion of dissolved LiCl (D{sub 7{sub Li}}/D{sub 6{sub Li}} = 0.99772 {+-} 0.00026). This difference in the diffusion coefficient of {sup 7}Li compared to {sup 6}Li is significantly less than reported in an earlier study, a difference we attribute to the fact that in the earlier study Li diffused through a membrane separating the water reservoirs. Our experiments involving Mg diffusing in water found no measurable isotopic fractionation (D{sub 25{sub Mg}}/D{sub 24{sub Mg}} = 1.00003 {+-} 0.00006). Cl isotopes were fractionated during diffusion in water (D{sub 37{sub Cl}}/D{sub 35{sub Cl}} = 0.99857 {+-} 0.00080) whether or not the co-diffuser (Li or Mg) was isotopically fractionated. The isotopic fractionation associated with the diffusion of ions in water is much smaller than values we found previously for the isotopic fractionation of Li and Ca isotopes by diffusion in molten silicate liquids. A major distinction between water and silicate liquids is that water, being a polar liquid, surrounds dissolved ions with hydration shells, which very likely play an important but still poorly understood role in reducing isotopic fractionation associated with diffusion.

  4. Multispecies Diffusion Capability For The AMP Nuclear Fuel Performance Code (LANL Milestone M31MS060301 Final Report)

    SciTech Connect (OSTI)

    Dilts, Gary A.

    2012-03-29

    This work addresses only diffusion. The contact solver in AMP was not sufficiently developed this year to attempt treatment of species contact. A cylindrical tensor diffusion coefficient model was added to the AMP code, with the KHHS model [1] implemented into the AMP material library as a specific example. A cylindrical tensor diffusion operator manufactured solution verification example was coded. Before meeting the full text of the milestone task, it remains to: (1) code and run a cylindrical tensor diffusion solver manufactured solution (2) code and run the validation example of [1] (3) document results. These are dependent on developing new capabilities for the AMP code requiring close collaboration with the AMP team at ORNL. The model implemented provides a good intermediate first step toward a general multi-species solver. The multi-species capability of the AMP nuclear fuel code [2] is intended to allow the modeling of radiation-driven redistribution of various elements through solid metal nuclear reactor fuels. The initial model AMP provides for U-Pu-Zr fuels is based on the analysis of the Integral Fast Reactor (IFR) fuel development program experiment X419 post-irradiation data described in [1], referred to here as the KHHS model. This model may be specific to that experiment, but it was thought to provide a good start for the AMP code, because it (1) is formulated at the engineering scale, (2) decouples the species from each other, (3) predetermines the phase boundaries so that reference to a phase diagram is not needed, and (4) one of the authors (Hayes) was the NEAMS Fuels IPSC manager for FY11. The KHHS model is formulated for radial fluxes as little axial redistribution is seen experimentally. As U-Pu-Zr fuel is irradiated, the constituents migrate to form three annular regions. The center region is Zr-enriched and U-depleted, the middle region is Zr-depleted and U-enriched, and the outer region is Zr-enriched and U-depleted. The Pu concentration stays roughly constant throughout with slight enrichment in the center and depletion near the surface. Pu acts as a solvent for the mixture. The experiment was only run to 1.9% burnup, so the model is not at this time applicable to the high-burnup scenarios that the AMP code is intended to eventually model.

  5. Effects of multi-component diffusion and heat release on laminar diffusion flame liftoff

    SciTech Connect (OSTI)

    Li, Zhiliang; Chen, Ruey-Hung [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816-2450 (United States); Phuoc, Tran X. [National Energy Technology Laboratory, Department of Energy, P.O. Box 10940, MS 84-340, Pittsburgh, PA 15261 (United States)

    2010-08-15

    Numerical simulations were conducted of the liftoff and stabilization phenomena of laminar jet diffusion flames of inert-diluted C{sub 3}H{sub 8} and CH{sub 4} fuels. Both non-reacting and reacting jets were investigated, including multi-component diffusivities and heat release effects (buoyancy and gas expansion). The role of Schmidt number for non-reacting jets was investigated, with no conclusive Schmidt number criterion for liftoff previously arrived at in similarity solutions. The cold-flow simulation for He-diluted CH{sub 4} fuel does not predict flame liftoff; however, adding heat release reaction lead to the prediction of liftoff, which is consistent with experimental observations. Including reaction was also found to improve liftoff height prediction for C{sub 3}H{sub 8} flames, with the flame base location differing from that in the similarity solution - the intersection of the stoichiometric and iso-velocity (equal to 1-D flame speed) is not necessary for flame stabilization (and thus liftoff). Possible mechanisms other than that proposed for similarity solution may better help to explain the stabilization and liftoff phenomena. (author)

  6. 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.

  7. 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.

  8. Monthly average clear-sky broadband irradiance database for worldwide solar heat gain and building cooling load calculations

    SciTech Connect (OSTI)

    Gueymard, Christian A.; Thevenard, Didier

    2009-11-15

    This paper establishes the formulation of a new clear-sky solar radiation model appropriate for algorithms calculating cooling loads in buildings. The aim is to replace the ASHRAE clear-sky model of 1967, whose limitations are well known and are reviewed. The new model is derived in two steps. The first step consists of obtaining a reference irradiance dataset from the REST2 model, which uses a high-performance, validated, two-band clear-sky algorithm. REST2 requires detailed inputs about atmospheric conditions such as aerosols, water vapor, ozone, and ground albedo. The development of global atmospheric datasets used as inputs to REST2 is reviewed. For the most part, these datasets are derived from space observations to guarantee universality and accuracy. In the case of aerosols, point-source terrestrial measurements were also used as ground truthing of the satellite data. The second step of the model consists of fits derived from a REST2-based reference irradiance dataset. These fits enable the derivation of compact, but relatively accurate expressions, for beam and diffuse clear-sky irradiance. The fitted expressions require the tabulation of only two pseudo-optical depths for each month of the year. The resulting model, and its tabulated data, are expected to be incorporated in the 2009 edition of the ASHRAE Handbook of Fundamentals. (author)

  9. 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

  10. Lanai high-density irradiance sensor network for characterizing solar

    Office of Scientific and Technical Information (OSTI)

    resource variability of MW-scale PV system. (Conference) | SciTech Connect Conference: Lanai high-density irradiance sensor network for characterizing solar resource variability of MW-scale PV system. Citation Details In-Document Search Title: Lanai high-density irradiance sensor network for characterizing solar resource variability of MW-scale PV system. Sandia National Laboratories (Sandia) and SunPower Corporation (SunPower) have completed design and deployment of an autonomous irradiance

  11. Inhalation radiotoxicity of irradiated thorium as a heavy water reactor

    Office of Scientific and Technical Information (OSTI)

    fuel (Conference) | SciTech Connect Conference: Inhalation radiotoxicity of irradiated 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 refueling capability of Heavy Water Reactors (HWRs), and their good neutron economy, allows a relatively high amount of neutron absorption in breeding materials to occur during normal fuel irradiation. This characteristic makes HWRs

  12. Transition from Irradiation-Induced Amorphization to Crystallization in

    Office of Scientific and Technical Information (OSTI)

    Nanocrystalline Silicon Carbide (Journal Article) | SciTech Connect Journal Article: Transition from Irradiation-Induced Amorphization to Crystallization in Nanocrystalline Silicon Carbide Citation Details In-Document Search Title: Transition from Irradiation-Induced Amorphization to Crystallization in Nanocrystalline Silicon Carbide Response to irradiation of nanocrystalline 3C-SiC is studied using 2 MeV Au+ ions near the critical temperature for amorphization and is compared to the

  13. Low cost fuel cell diffusion layer configured for optimized anode water

    Office of Scientific and Technical Information (OSTI)

    management (Patent) | SciTech Connect Patent: Low cost fuel cell diffusion layer configured for optimized anode water management Citation Details In-Document Search Title: Low cost fuel cell diffusion layer configured for optimized anode water management A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel

  14. Big Data Projects on Solar Tech Evolution and Diffusion

    Broader source: Energy.gov [DOE]

    This is the meeting agenda from the Big Data Projects on Solar Technology Evolution and Diffusion kickoff meeting, held on July 15, 2013 in Arlington, VA and facilitated by the SunShot Initiative.

  15. EM Begins Demolishing K-31 Gaseous Diffusion Building

    Broader source: Energy.gov [DOE]

    OAK RIDGE, Tenn. – EM's demolition of the K-31 Building at Oak Ridge’s East Tennessee Technology Park (ETTP) began Wednesday, marking the removal of the fourth of five gaseous diffusion buildings at the former uranium enrichment site.

  16. Pre-plated reactive diffusion-bonded battery electrode plaques

    DOE Patents [OSTI]

    Maskalick, Nicholas J.

    1984-01-01

    A high strength, metallic fiber battery plaque is made using reactive diffusion bonding techniques, where a substantial amount of the fibers are bonded together by an iron-nickel alloy.

  17. Energy Department Completes K-25 Gaseous Diffusion Building Demolition...

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

    The K-25 building, located at the East Tennessee Technology Park formerly known as the Oak Ridge Gaseous Diffusion Plant, was built in 1943 as part of the Manhattan Project. At the ...

  18. Generalizing the self-healing diffusion Monte Carlo approach...

    Office of Scientific and Technical Information (OSTI)

    Generalizing the self-healing diffusion Monte Carlo approach to finite temperature: A path for the optimization of low-energy many-body bases Citation Details In-Document Search ...

  19. Thermodynamic properties and diffusion of water + methane binary mixtures

    SciTech Connect (OSTI)

    Shvab, I.; Sadus, Richard J.

    2014-03-14

    Thermodynamic and diffusion properties of water + methane mixtures in a single liquid phase are studied using NVT molecular dynamics. An extensive comparison is reported for the thermal pressure coefficient, compressibilities, expansion coefficients, heat capacities, Joule-Thomson coefficient, zero frequency speed of sound, and diffusion coefficient at methane concentrations up to 15% in the temperature range of 298650 K. The simulations reveal a complex concentration dependence of the thermodynamic properties of water + methane mixtures. The compressibilities, heat capacities, and diffusion coefficients decrease with increasing methane concentration, whereas values of the thermal expansion coefficients and speed of sound increase. Increasing methane concentration considerably retards the self-diffusion of both water and methane in the mixture. These effects are caused by changes in hydrogen bond network, solvation shell structure, and dynamics of water molecules induced by the solvation of methane at constant volume conditions.

  20. Spectral Components Analysis of Diffuse Emission Processes (Journal...

    Office of Scientific and Technical Information (OSTI)

    This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and ... We develop a novel method to separate the components of a diffuse emission process based ...

  1. Role of carbon surface diffusion and strain on the epitaxial...

    Office of Scientific and Technical Information (OSTI)

    epitaxial growth of graphene on SiC(0001). Citation Details In-Document Search Title: Role of carbon surface diffusion and strain on the epitaxial growth of graphene on SiC(0001). ...

  2. DOE Issues Final Request for Proposal for Paducah Gaseous Diffusion...

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

    DOE Issues Final Request for Proposal for Paducah Gaseous Diffusion Plant Support Services October 6, 2014 - 4:13pm Addthis Media Contact Bill Taylor, 803-952-8564, bill.taylor@srs...

  3. A molecular dynamics investigation of the diffusion characteristics...

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

    137, 83-91 (2011) DOI: 10.1016j.micromeso.2010.08.026 Full-size image (36 K) Abstract: Molecular dynamics (MD) simulations are used to investigate the diffusion characteristics...

  4. Influence of adsorption on the diffusion selectivity for mixture...

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

    Baten, J. Membr. Sci., 369, 545-549 (2011) DOI: 10.1016j.memsci.2010.12.042 Abstract: Molecular dynamics (MD) simulations were carried out to determine the self-diffusivities,...

  5. Metallic diffusion process and improved article produced thereby

    DOE Patents [OSTI]

    Morrow, M. Stanley; Schechter, Donald E.; Grant, Harley A.

    2003-04-29

    A uniquely surface-modified metallic part is provided by the utilization of microwave energy to promote diffusion of desired metals into the surface of the formed metallic part.

  6. Numerical Modeling Studies of The Dissolution-Diffusion-Convection...

    Office of Scientific and Technical Information (OSTI)

    CO2 Storage in Saline Aquifers Citation Details In-Document Search Title: Numerical Modeling Studies of The Dissolution-Diffusion-Convection ProcessDuring CO2 Storage in ...

  7. 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.

  8. 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.

  9. Irradiation Effects on Human Cortical Bone Fracture Behavior

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

    of sustained irradiation damage. Combining in situ mechanical testing with synchrotron x-ray diffraction imaging andor tomography, is a popular method of investigating...

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

    Office of Scientific and Technical Information (OSTI)

    A compact fatigue testing machine that can be easily inserted into a hot cell for characterization of irradiated materials is beneficial to help determine relative fatigue ...

  11. Transition from Irradiation-Induced Amorphization to Crystallization...

    Office of Scientific and Technical Information (OSTI)

    using in-situ ion channeling, ex-situ x-ray diffraction, and helium ion microscopy. ... IONS; ION CHANNELING; IRRADIATION; MICROSCOPY; NUCLEAR ENERGY; NUCLEAR FUELS; SILICON ...

  12. 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'...

  13. 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.

  14. FATIGUE LIFE PREDICTION FOR STEELS IN PULSATING IRRADIATED SYSTEMS...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: FATIGUE LIFE PREDICTION FOR STEELS IN PULSATING IRRADIATED SYSTEMS Citation Details In-Document Search Title: FATIGUE LIFE PREDICTION FOR STEELS IN PULSATING ...

  15. 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...

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

    Office of Scientific and Technical Information (OSTI)

    Center (NCERC) at the Nevada National Security Site (NNSS) was used to irradiate twelve ... foils were shipped to Los Alamos National Laboratory (LANL) for radiochemical analysis. ...

  17. 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...

  18. Measuring Broadband IR Irradiance in the Direct Solar Beam (Presentati...

    Office of Scientific and Technical Information (OSTI)

    Measuring Broadband IR Irradiance in the Direct Solar Beam (Presentation) Citation Details ... Visit OSTI to utilize additional information resources in energy science and technology. A ...

  19. 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

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

    Energy Savers [EERE]

    Summary Report: Post-Irradiation Examination of Zircaloy-4 Samples in Target Capsules and Initiation of Bending Fatigue Testing for Used Nuclear Fuel Vibration Integrity ...

  1. 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...

  2. First-principles studies on vacancy-modified interstitial diffusion

    Office of Scientific and Technical Information (OSTI)

    mechanism of oxygen in nickel, associated with large-scale atomic simulation techniques (Journal Article) | SciTech Connect First-principles studies on vacancy-modified interstitial diffusion mechanism of oxygen in nickel, associated with large-scale atomic simulation techniques Citation Details In-Document Search Title: First-principles studies on vacancy-modified interstitial diffusion mechanism of oxygen in nickel, associated with large-scale atomic simulation techniques Authors: Fang, H

  3. Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - April

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

    2013 | Department of Energy April 2013 Independent Oversight Review, Portsmouth Gaseous Diffusion Plant - April 2013 April 2013 Review of the Integrated Safety Management System Phase I Verification Review at the Portsmouth Gaseous Diffusion Plant The Office of Enforcement and Oversight (Independent Oversight), within the Office of Health, Safety and Security (HSS), conducted an independent review of the U.S. Department of Energy (DOE) Portsmouth/Paducah Project Office (PPPO). The objective

  4. DOE Awards Contract for Paducah Gaseous Diffusion Plant Infrastructure

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

    Support Services | Department of Energy Paducah Gaseous Diffusion Plant Infrastructure Support Services DOE Awards Contract for Paducah Gaseous Diffusion Plant Infrastructure Support Services June 17, 2015 - 5:45pm Addthis Media Contact: Lynette Chafin, 513-246-0461, Lynette.Chafin@emcbc.doe.gov Cincinnati -- The U.S. Department of Energy (DOE) today announced the award of a contract to Swift & Staley, Inc. of Kevil, Kentucky, for the performance of infrastructure support services at the

  5. DOE Seeks Small Businesses for Portsmouth Gaseous Diffusion Plant

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

    Infrastructure Support Services | Department of Energy Seeks Small Businesses for Portsmouth Gaseous Diffusion Plant Infrastructure Support Services DOE Seeks Small Businesses for Portsmouth Gaseous Diffusion Plant Infrastructure Support Services July 2, 2014 - 12:00pm Addthis Media Contact Bill Taylor, 803-952-8564, bill.taylor@srs.gov Cincinnati -- The U.S. Department of Energy (DOE) today issued a Draft Request for Proposal (RFP) seeking eligible small businesses under North American

  6. Scale dependency of the effective matrix diffusion coefficient

    SciTech Connect (OSTI)

    Liu, H.H.; Bodvarsson, G.S.; Zhang, G.

    2003-05-30

    It has been recognized that matrix diffusion is an important process for retarding solute transport in fractured rock. Based on analyses of tracer transport data from a number of field tests, we demonstrate for the first time that the effective matrix-diffusion coefficient may be scale dependent and generally increases with test scale. A preliminary theoretical explanation of this scale dependency is also presented, based on the hypothesis that solute travel paths within a fracture network are fractals.

  7. Continuum modeling of diffusion and dispersion in dense granular flows

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Continuum modeling of diffusion and dispersion in dense granular flows Citation Details In-Document Search Title: Continuum modeling of diffusion and dispersion in dense granular flows Authors: Christov, Ivan C [1] ; Stone, Howard A [2] + Show Author Affiliations Los Alamos National Laboratory [Los Alamos National Laboratory Mechanical & Aerospace Engineering, Princeton University [Mechanical & Aerospace Engineering, Princeton University Publication

  8. Diffusive transfer of polarized 3He gas through depolarizing magnetic

    Office of Scientific and Technical Information (OSTI)

    gradients (Journal Article) | SciTech Connect Diffusive transfer of polarized 3He gas through depolarizing magnetic gradients Citation Details In-Document Search This content will become publicly available on April 8, 2017 Title: Diffusive transfer of polarized 3He gas through depolarizing magnetic gradients Authors: Maxwell, J. D. Search SciTech Connect for author "Maxwell, J. D." Search SciTech Connect for ORCID "0000000327104646" Search orcid.org for ORCID

  9. Optical processing furnace with quartz muffle and diffuser plate

    DOE Patents [OSTI]

    Sopori, B.L.

    1996-11-19

    An optical furnace for annealing a process wafer is disclosed comprising a source of optical energy, a quartz muffle having a door to hold the wafer for processing, and a quartz diffuser plate to diffuse the light impinging on the quartz muffle; a feedback system with a light sensor located in the wall of the muffle is also provided for controlling the source of optical energy. 5 figs.

  10. Paducah Gaseous Diffusion Plant Compliance Order, September 10, 1997

    Office of Environmental Management (EM)

    Energy Southwest Plume Paducah Gaseous Diffusion Plant - GW OU Southwest Plume January 1, 2014 - 12:00pm Addthis US Department of Energy Groundwater Database Groundwater Master Report InstallationName, State: Paducah Gaseous Diffusion Plant, KY Responsible DOE Office: Office of Environmental Management Plume Name: GW OW Southwest Plume Remediation Contractor: LATA Environmental Services of Kentucky, LLC PBS Number: PA-0040 Report Last Updated: 2014 Contaminants Halogenated VOCs/SVOCs

  11. Gas Diffusion Electrodes and Methods for Fabricating and Testing Same -

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

    Energy Innovation Portal Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Gas Diffusion Electrodes and Methods for Fabricating and Testing Same Brookhaven National Laboratory Contact BNL About This Technology Publications: PDF Document Publication Fabricating and Measuring Low-Platinum Content HOR/HER Gas Diffusion Electrodes (89 KB) Technology Marketing Summary A typical membrane electrode assembly (MEA) consists of five distinct layers: A polymer

  12. 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 hydrogen water chemistry mitigation technology may decrease as fluence increases for high-stress intensity factors. This report describes a program plan to determine the efficiency of hydrogen water chemistry as a function of the stress intensity factor applied and fluence. The use of existing, available, materials and the generation of additional materials via irradiation in a research reactor are considered.

  13. Hafnium radioisotope recovery from irradiated tantalum

    DOE Patents [OSTI]

    Taylor, Wayne A. (Los Alamos, NM); Jamriska, David J. (Los Alamos, NM)

    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.

  14. 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)

  15. 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

  16. 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 cracks were found in the EBW (electron beam weld) of the LBE container in the intensive irradiation zone of the target, which should be formed during irradiation. In the SS 316L steel of the flow guide tube, inclusions or precipitates enriched with O, Si, S, Ca, Ti and Mn were observed. Many of them are very long, up to a few mm, and located on grain boundaries along the extrusion direction of the tube. The degradation of the mechanical properties of the T91 and SS 316L steels has been investigated by conducting tensile tests on the specimens extracted from the T91 and SS 316L components in the intensive irradiation region. The results obtained from the proton beam window of the T91 calotte exhibit a good ductility of T91 steel after irradiation at 6-7 dpa (displacement per atom) in contact with flowing LBE.

  17. Absorption and scattering of laser radiation by the diffusion flame of aviation kerosene

    SciTech Connect (OSTI)

    Gvozdev, S V; Glova, A F; Dubrovskii, V Yu; Durmanov, S T; Krasyukov, A G; Lysikov, A Yu; Smirnov, G V; Solomakhin, V B

    2012-04-30

    The absorption coefficient of the radiation of a repetitively pulsed Nd : YAG laser with an average output power up to 6 W and of a cw ytterbium optical fibre laser with an output power up to 3 kW was measured in the diffusion flame of aviation kerosene burning on a free surface in the atmospheric air. The absorption coefficient as a function of flame length, radiation power, and radiation intensity, which was varied in the {approx}10{sup 3} - 5 Multiplication-Sign 10{sup 4} W cm{sup -2} range, was obtained for two distances (1 and 2 cm) between the laser beam axis and the surface. The coefficient of radiation absorption by kerosene flame was compared with that in ethanol and kerosene - ethanol mixture flames. The radiation power scattered by a small segment of the kerosene flame irradiated by Nd : YAG laser radiation was measured as a function of longitudinal and azimuthal coordinates. An estimate was made of the total scattered radiation power.

  18. Molecular dynamics simulations of hydrogen diffusion in aluminum

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

    Zhou, X. W.; El Gabaly, F.; Stavila, V.; Allendorf, M. D.

    2016-03-23

    In this study, hydrogen diffusion impacts the performance of solid-state hydrogen storage materials and contributes to the embrittlement of structural materials under hydrogen-containing environments. In atomistic simulations, the diffusion energy barriers are usually calculated using molecular statics simulations where a nudged elastic band method is used to constrain a path connecting the two end points of an atomic jump. This approach requires prior knowledge of the “end points”. For alloy and defective systems, the number of possible atomic jumps with respect to local atomic configurations is tremendous. Even when these jumps can be exhaustively studied, it is still unclear howmore » they can be combined to give an overall diffusion behavior seen in experiments. Here we describe the use of molecular dynamics simulations to determine the overall diffusion energy barrier from the Arrhenius equation. This method does not require information about atomic jumps, and it has additional advantages, such as the ability to incorporate finite temperature effects and to determine the pre-exponential factor. As a test case for a generic method, we focus on hydrogen diffusion in bulk aluminum. We find that the challenge of this method is the statistical variation of the results. However, highly converged energy barriers can be achieved by an appropriate set of temperatures, output time intervals (for tracking hydrogen positions), and a long total simulation time. Our results help elucidate the inconsistencies of the experimental diffusion data published in the literature. The robust approach developed here may also open up future molecular dynamics simulations to rapidly study diffusion properties of complex material systems in multidimensional spaces involving composition and defects.« less

  19. Enhanced Generic Phase-field Model of Irradiation Materials: Fission Gas Bubble Growth Kinetics in Polycrystalline UO2

    SciTech Connect (OSTI)

    Li, Yulan; Hu, Shenyang Y.; Montgomery, Robert O.; Gao, Fei; Sun, Xin

    2012-05-30

    Experiments show that inter-granular and intra-granular gas bubbles have different growth kinetics which results in heterogeneous gas bubble microstructures in irradiated nuclear fuels. A science-based model predicting the heterogeneous microstructure evolution kinetics is desired, which enables one to study the effect of thermodynamic and kinetic properties of the system on gas bubble microstructure evolution kinetics and morphology, improve the understanding of the formation mechanisms of heterogeneous gas bubble microstructure, and provide the microstructure to macroscale approaches to study their impact on thermo-mechanical properties such as thermo-conductivity, gas release, volume swelling, and cracking. In our previous report 'Mesoscale Benchmark Demonstration, Problem 1: Mesoscale Simulations of Intra-granular Fission Gas Bubbles in UO2 under Post-irradiation Thermal Annealing', we developed a phase-field model to simulate the intra-granular gas bubble evolution in a single crystal during post-irradiation thermal annealing. In this work, we enhanced the model by incorporating thermodynamic and kinetic properties at grain boundaries, which can be obtained from atomistic simulations, to simulate fission gas bubble growth kinetics in polycrystalline UO2 fuels. The model takes into account of gas atom and vacancy diffusion, vacancy trapping and emission at defects, gas atom absorption and resolution at gas bubbles, internal pressure in gas bubbles, elastic interaction between defects and gas bubbles, and the difference of thermodynamic and kinetic properties in matrix and grain boundaries. We applied the model to simulate gas atom segregation at grain boundaries and the effect of interfacial energy and gas mobility on gas bubble morphology and growth kinetics in a bi-crystal UO2 during post-irradiation thermal annealing. The preliminary results demonstrate that the model can produce the equilibrium thermodynamic properties and the morphology of gas bubbles at grain boundaries for given grain boundary properties. More validation of the model capability in polycrystalline is underway.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Test Program for High Efficiency Gas Turbine Exhaust Diffuser

    SciTech Connect (OSTI)

    Norris, Thomas R.

    2009-12-31

    This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust geometry. Importantly, low frequency diffuser noise was reduced by 5 dB or more, compared to the baseline. Appolicability to other diffuser geometries is yet to be demonstrated.

  8. Basic Studies of Non-Diffusive Transport in Plasmas

    SciTech Connect (OSTI)

    Morales, George J.; Maggs, James E.

    2014-10-25

    The project expanded and developed mathematical descriptions, and corresponding numerical modeling, of non-diffusive transport to incorporate new perspectives derived from basic transport experiments performed in the LAPD device at UCLA, and at fusion devices throughout the world. By non-diffusive it is meant that the transport of fundamental macroscopic parameters of a system, such as temperature and density, does not follow the standard diffusive behavior predicted by a classical Fokker-Planck equation. The appearance of non-diffusive behavior is often related to underlying microscopic processes that cause the value of a system parameter, at one spatial position, to be linked to distant events, i.e., non-locality. In the LAPD experiments the underlying process was traced to large amplitude, coherent drift-waves that give rise to chaotic trajectories. Significant advances were made in this project. The results have lead to a new perspective about the fundamentals of edge transport in magnetically confined plasmas; the insight has important consequences for worldwide studies in fusion devices. Progress was also made in advancing the mathematical techniques used to describe fractional diffusion.

  9. Microstructural characterization of a thin film ZrN diffusion barrier in an As-fabricated U7Mo/Al matrix dispersion fuel plate

    SciTech Connect (OSTI)

    Keiser, Dennis D.; Perez, Emmanuel; Wiencek, Tom; Leenaers, Ann; Van den Berghe, Sven

    2015-03-01

    The United States High Performance Research Reactor Fuel Development program is developing low enriched uranium fuels for application in research and test reactors. One concept utilizes U7 wt.% Mo (U7Mo) fuel particles dispersed in Al matrix, where the fuel particles are coated with a 1 ?m-thick ZrN coating. The ZrN serves as a diffusion barrier to eliminate a deleterious reaction that can occur between U7Mo and Al when a dispersion fuel is irradiated under aggressive reactor conditions. To investigate the final microstructure of a physically-vapor-deposited ZrN coating in a dispersion fuel plate after it was fabricated using a rolling process, characterization samples were taken from a fuel plate that was fabricated at 500 C using ZrN-coated U7Mo particles, Al matrix and AA6061 cladding. Scanning electron and transmission electron microscopy analysis were performed. Data from these analyses will be used to support future microstructural examinations of irradiated fuel plates, in terms of understanding the effects of irradiation on the ZrN microstructure, and to determine the role of diffusion barrier microstructure in eliminating fuel/matrix interactions during irradiation. The as-fabricated coating was determined to be cubic-ZrN (cF8) phase. It exhibited a columnar microstructure comprised of nanometer-sized grains and a region of relatively high porosity, mainly near the Al matrix. Small impurity-containing phases were observed at the U7Mo/ZrN interface, and no interaction zone was observed at the ZrN/Al interface. The bonding between the U7Mo and ZrN appeared to be mechanical in nature. A relatively high level of oxygen was observed in the ZrN coating, extending from the Al matrix in the ZrN coating in decreasing concentration. The above microstructural characteristics are discussed in terms of what may be most optimal for a diffusion barrier in a dispersion fuel plate application.

  10. 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?.

  11. Brain Tumor Therapy-Induced Changes in Normal-Appearing Brainstem Measured With Longitudinal Diffusion Tensor Imaging

    SciTech Connect (OSTI)

    Hua Chiaho; Merchant, Thomas E.; Gajjar, Amar; Broniscer, Alberto; Zhang, Yong; Li Yimei; Glenn, George R.; Kun, Larry E.; Ogg, Robert J.

    2012-04-01

    Purpose: To characterize therapy-induced changes in normal-appearing brainstems of childhood brain tumor patients by serial diffusion tensor imaging (DTI). Methods and Materials: We analyzed 109 DTI studies from 20 brain tumor patients, aged 4 to 23 years, with normal-appearing brainstems included in the treatment fields. Those with medulloblastomas, supratentorial primitive neuroectodermal tumors, and atypical teratoid rhabdoid tumors (n = 10) received postoperative craniospinal irradiation (23.4-39.6 Gy) and a cumulative dose of 55.8 Gy to the primary site, followed by four cycles of high-dose chemotherapy. Patients with high-grade gliomas (n = 10) received erlotinib during and after irradiation (54-59.4 Gy). Parametric maps of fractional anisotropy (FA) and apparent diffusion coefficient (ADC) were computed and spatially registered to three-dimensional radiation dose data. Volumes of interest included corticospinal tracts, medial lemnisci, and the pons. Serving as an age-related benchmark for comparison, 37 DTI studies from 20 healthy volunteers, aged 6 to 25 years, were included in the analysis. Results: The median DTI follow-up time was 3.5 years (range, 1.6-5.0 years). The median mean dose to the pons was 56 Gy (range, 7-59 Gy). Three patterns were seen in longitudinal FA and apparent diffusion coefficient changes: (1) a stable or normal developing time trend, (2) initial deviation from normal with subsequent recovery, and (3) progressive deviation without evidence of complete recovery. The maximal decline in FA often occurred 1.5 to 3.5 years after the start of radiation therapy. A full recovery time trend could be observed within 4 years. Patients with incomplete recovery often had a larger decline in FA within the first year. Radiation dose alone did not predict long-term recovery patterns. Conclusions: Variations existed among individual patients after therapy in longitudinal evolution of brainstem white matter injury and recovery. Early response in brainstem anisotropy may serve as an indicator of the recovery time trend over 5 years after radiation therapy.

  12. Configurational diffusion of asphaltenes in fresh and aged catalysts extrudates

    SciTech Connect (OSTI)

    Guin, J.A.; Tarrer, A.R.

    1992-01-01

    The objective of this research is to determine the relationship between the size and shape of coal and petroleum macromolecules and their diffusion rates i.e., effective diffusivities, in catalyst pore structures. That is, how do the effective intrapore diffusivities depend on molecule configuration and pore geometry. Based on the work done, the following conclusions can be drawn: The intrapore diffusional model can be set up mathematically based on certain assumptions, and the mathematical model can be solved numberically; the numerical solution discussed in this quarterly report can be used for typical situations given suitable values for parameters E, R and n; comparison with known solutions for special cases shows the numerical solution to be accurate.

  13. Josephson phase diffusion in the superconducting quantum interference device ratchet

    SciTech Connect (OSTI)

    Spiechowicz, Jakub; Łuczka, Jerzy

    2015-05-15

    We study diffusion of the Josephson phase in the asymmetric superconducting quantum interference device (SQUID) subjected to a time-periodic current and pierced by an external magnetic flux. We analyze a relation between phase diffusion and quality of transport characterized by the dc voltage across the SQUID and efficiency of the device. In doing so, we concentrate on the previously reported regime [J. Spiechowicz and J. Łuczka, New J. Phys. 17, 023054 (2015)] for which efficiency of the SQUID attains a global maximum. For long times, the mean-square displacement of the phase is a linear function of time, meaning that diffusion is normal. Its coefficient is small indicating rather regular phase evolution. However, it can be magnified several times by tailoring experimentally accessible parameters like amplitudes of the ac current or external magnetic flux. Finally, we prove that in the deterministic limit this regime is essentially non-chaotic and possesses an unexpected simplicity of attractors.

  14. Integral approximations to classical diffusion and smoothed particle hydrodynamics

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

    Du, Qiang; Lehoucq, R. B.; Tartakovsky, A. M.

    2014-12-31

    The contribution of the paper is the approximation of a classical diffusion operator by an integral equation with a volume constraint. A particular focus is on classical diffusion problems associated with Neumann boundary conditions. By exploiting this approximation, we can also approximate other quantities such as the flux out of a domain. Our analysis of the model equation on the continuum level is closely related to the recent work on nonlocal diffusion and peridynamic mechanics. In particular, we elucidate the role of a volumetric constraint as an approximation to a classical Neumann boundary condition in the presence of physical boundary.more » The volume-constrained integral equation then provides the basis for accurate and robust discretization methods. As a result, an immediate application is to the understanding and improvement of the Smoothed Particle Hydrodynamics (SPH) method.« less

  15. Characterization and modeling of thermal diffusion and aggregation in nanofluids.

    SciTech Connect (OSTI)

    Gharagozloo, Patricia E.; Goodson, Kenneth E.

    2010-05-01

    Fluids with higher thermal conductivities are sought for fluidic cooling systems in applications including microprocessors and high-power lasers. By adding high thermal conductivity nanoscale metal and metal oxide particles to a fluid the thermal conductivity of the fluid is enhanced. While particle aggregates play a central role in recent models for the thermal conductivity of nanofluids, the effect of particle diffusion in a temperature field on the aggregation and transport has yet to be studied in depth. The present work separates the effects of particle aggregation and diffusion using parallel plate experiments, infrared microscopy, light scattering, Monte Carlo simulations, and rate equations for particle and heat transport in a well dispersed nanofluid. Experimental data show non-uniform temporal increases in thermal conductivity above effective medium theory and can be well described through simulation of the combination of particle aggregation and diffusion. The simulation shows large concentration distributions due to thermal diffusion causing variations in aggregation, thermal conductivity and viscosity. Static light scattering shows aggregates form more quickly at higher concentrations and temperatures, which explains the increased enhancement with temperature reported by other research groups. The permanent aggregates in the nanofluid are found to have a fractal dimension of 2.4 and the aggregate formations that grow over time are found to have a fractal dimension of 1.8, which is consistent with diffusion limited aggregation. Calculations show as aggregates grow the viscosity increases at a faster rate than thermal conductivity making the highly aggregated nanofluids unfavorable, especially at the low fractal dimension of 1.8. An optimum nanoparticle diameter for these particular fluid properties is calculated to be 130 nm to optimize the fluid stability by reducing settling, thermal diffusion and aggregation.

  16. 1

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

    the Estimation of Clear-Sky Upwelling Shortwave and Longwave C.N. Long Pacific Northwest National Laboratory Richland, Washington Introduction Previous work (Long and Ackerman 2000; Long 2004) has concentrated on estimating the downwelling clear-sky irradiances and calculating the effect of clouds on the downwelling radiative energy budget. However, cloud forcing is defined for the difference between clear- and cloudy-sky net radiation, which includes the upwelling components. Thus, if we are to

  17. Methodology for Calculating Spectral Surface Albedo Using ARM MFSR and MFR

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

    Data Methodology for Calculating Spectral Surface Albedo Using ARM MFSR and MFR Data Gaustad, Krista Pacific Northwest National Laboratory Long, Chuck Pacific Northwest National Laboratory Category: Radiation This poster will describe a methodology for identifying the best estimate downwelling and upwelling irradiance measurements for use in calculating a global and spectral albedo for the area located near the SGP ARM's central facility 10m tower. The best estimate MFRSR downwelling global

  18. Effects of surface diffusion on high temperature selective emitters

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

    Peykov, Daniel; Yeng, Yi Xiang; Celanovic, Ivan; Joannopoulos, John D.; Schuh, Christopher A.

    2015-01-01

    Using morphological and optical simulations of 1D tantalum photonic crystals at 1200K, surface diffusion was determined to gradually reduce the efficiency of selective emitters. This was attributed to shifting resonance peaks and declining emissivity caused by changes to the cavity dimensions and the aperture width. Decreasing the structures curvature through larger periods and smaller cavity widths, as well as generating smoother transitions in curvature through the introduction of rounded cavities, was found to alleviate this degradation. An optimized structure, that shows both high efficiency selective emissivity and resistance to surface diffusion, was presented.

  19. Self-Diffusion in a Liquid Complex Plasma

    SciTech Connect (OSTI)

    Nunomura, S.; Samsonov, D.; Zhdanov, S.; Morfill, G.

    2006-01-13

    Self-diffusion has been experimentally studied in a two-dimensional underdamped liquid complex (dusty) plasma. It was found that the self-diffusion coefficient D increases linearly with the temperature T: D/{omega}{sub E}a{sup 2}=(0.019{+-}0.007)(T/T{sub m}-1), where T{sub m}, {omega}{sub E}, and a are the melting temperature, the Einstein frequency, and the mean particle separation, respectively. No superdiffusion was observed, whereas a subdiffusion occurred at temperatures close to melting.

  20. Observation of Large Photoacoustic Signal Phase Changes During a Diffusion

    Office of Scientific and Technical Information (OSTI)

    Process (Journal Article) | SciTech Connect Journal Article: Observation of Large Photoacoustic Signal Phase Changes During a Diffusion Process Citation Details In-Document Search Title: Observation of Large Photoacoustic Signal Phase Changes During a Diffusion Process No abstract prepared. Authors: Stanley J. Bajic ; Roger W. Jones ; Jones F. McClelland Publication Date: 2005-09-01 OSTI Identifier: 884839 Report Number(s): IS-J 7054 Journal ID: ISSN 0003-7028; APSPA4; TRN: US200616%%59 DOE

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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, 491 lbf, or 589 lbf. Loads were consistently within 5% of the specified values throughout the experiment. Stack displacement increased consistently throughout the experiment with total displacement ranging from 1 to 1.5 inches. No anomalous values were identified. During reactor outages, a set of pneumatic rams are used to raise the stacks of graphite creep specimens to ensure the specimens have not become stuck within the test train. This stack raising was performed after all cycles when the capsule was in the reactor. All stacks were raised successfully after each cycle. The load and displacement data are Qualified

  7. Application of Perona Malik anisotropic diffusion on digital radiographic image

    SciTech Connect (OSTI)

    Halim, Suhaila Abd; Razak, Rohayu Abdul; Ibrahim, Arsmah; Manurung, Yupiter HP

    2014-07-10

    Perona Malik Anisotropic Diffusion (PMAD) is a very useful and efficient denoising technique if the parameters are properly selected. Overestimating the parameters may cause oversmoothed and underestimating it may leave unfiltered noise. This makes the selection of parameters a crucial process. In this paper the PMAD model is solved using a finite difference scheme The discretized model is evaluated using different diffusion coefficient of exponential and quadratic on defective radiographic images in terms of quality and efficiency. In the application of the PMAD model on image data, a set of defective radiographic images of welding is used as input data. Peak Signal to Noise Ratio (PSNR), Structural Similarity Measure (SSIM) and temporal time are used to evaluate the performance of the model. The implementation of the experiment has been carried out using MATLAB R2009a. In terms of quality, results show that the Quadratic Diffusion Coefficient Function (QDCF) provides better results compared with the Exponential Diffusion Coefficient Function (EDCF). In conclusion, the denoising effect using PMAD model based on finite difference scheme shows able to improve image quality by removing noise in the defective radiographic image.

  8. Energetics of melts from thermal diffusion studies. Final report

    SciTech Connect (OSTI)

    Lesher, C.E.

    1998-12-01

    Most processes in geology are a consequence at some level of the flow of energy or mass. Heat conduction and chemical diffusion are examples of two of these sorts of flows which are driven by temperature and chemical potential imbalances, respectively. In the general case these flows may be coupled so that, for instance, a temperature gradient may result in a flow of mass as well as heat. This effect in liquids was demonstrated by Soret (1879) and bears his name. In gases or solids the phenomenon is given the general name thermal diffusion. It was the purpose of this research program to examine the Soret effect in molten silicates under laboratory conditions. Results of these experiments are used to evaluate the form and quantitative values of many thermodynamic and kinetic properties of silicate melts over a range of temperature, pressure, and bulk composition. The author published a comprehensive review and synthesis with a microscopic theoretical explanation for the effect at low pressure in silicate liquids of geological interest. He conducted experimental investigations of molecular diffusion in the absence of a thermal gradient through experiments involving dissolution of solid silicates in molten silicate and interdiffusion of species between miscible silicate liquids. Collectively these results enable the author to construct a more comprehensive model of molecular diffusion in magmatic liquids. He has applied this model to problems of magma mixing and crustal assimilation.

  9. Diffusion Databases for Mg-ICME | Department of Energy

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

    2 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting PDF icon lm036_kulkarni_2012_o.pdf More Documents & Publications Diffusion Databases for ICME Vehicle Technologies Office: 2010 Lightweight Materials R&D Annual Progress Report Low-Cost Magnesium Sheet Production using the Twin Roll Casting Process and Asymmetric Rolling

  10. Irradiation behavior of the interaction product of U-Mo fuel particle dispersion in an Al matrix.

    SciTech Connect (OSTI)

    Kim, Y.S.; Hofman, G. (Nuclear Engineering Division)

    2012-06-01

    Irradiation performance of U-Mo fuel particles dispersed in Al matrix is stable in terms of fuel swelling and is suitable for the conversion of research and test reactors from highly enriched uranium (HEU) to low enriched uranium (LEU). However, tests of the fuel at high temperatures and high burnups revealed obstacles caused by the interaction layers forming between the fuel particle and matrix. In some cases, fission gas filled pores grow and interconnect in the interdiffusion layer resulting in fuel plate failure. Postirradiation observations are made to examine the behavior of the interdiffusion layers. The interdiffusion layers show a fluid-like behavior characteristic of amorphous materials. In the amorphous interdiffusion layers, fission gas diffusivity is high and the material viscosity is low so that the fission gas pores readily form and grow. Based on the observations, a pore formation mechanism is proposed and potential remedies to suppress the pore growth are also introduced.

  11. 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.

  12. Recovery of germanium-68 from irradiated targets

    DOE Patents [OSTI]

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

    1993-01-01

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

  13. PROCESSING OF NEUTRON-IRRADIATED URANIUM

    DOE Patents [OSTI]

    Hopkins, H.H. Jr.

    1960-09-01

    An improved "Purex" process for separating uranium, plutonium, and fission products from nitric acid solutions of neutron-irradiated uranium is offered. Uranium is first extracted into tributyl phosphate (TBP) away from plutonium and fission products after adjustment of the acidity from 0.3 to 0.5 M and heating from 60 to 70 deg C. Coextracted plutonium, ruthenium, and fission products are fractionally removed from the TBP by three scrubbing steps with a 0.5 M nitric acid solution of ferrous sulfamate (FSA), from 3.5 to 5 M nitric acid, and water, respectively, and the purified uranium is finally recovered from the TBP by precipitation with an aqueous solution of oxalic acid. The plutonium in the 0.3 to 0.5 M acid solution is oxidized to the tetravalent state with sodium nitrite and extracted into TBP containing a small amount of dibutyl phosphate (DBP). Plutonium is then back-extracted from the TBP-DBP mixture with a nitric acid solution of FSA, reoxidized with sodium nitrite in the aqueous strip solution obtained, and once more extracted with TBP alone. Finally the plutonium is stripped from the TBP with dilute acid, and a portion of the strip solution thus obtained is recycled into the TBPDBP for further purification.

  14. Irradiation Assisted Grain Boundary Segregation in Steels

    SciTech Connect (OSTI)

    Lu, Zheng; Faulkner, Roy G.

    2008-07-01

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

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

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

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

    2014-12-01

    Tungsten samples were irradiated by neutrons in the High Flux Isotope Reactor, Oak Ridge National Laboratory at reactor coolant temperatures of 50-70°C 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 5×10²⁵ m⁻² to reach a total ion fluence of 1×10²⁶ m⁻² in order to investigate the near surface deuterium retention and saturation via nuclear reaction analysis. Finalmore » thermal desorption spectroscopy was performed to elucidate irradiation effect on total deuterium retention. Nuclear reaction analysis results showed that the maximum near surface (<5 µm 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 µm depth for 0.025 dpa and 35 µm depth for 0.025 dpa) at 500 °C case even in the relatively low ion fluence of 10²⁶ m⁻².« less

  16. NREL Solar Radiation Research Laboratory (SRRL): Baseline Measurement System (BMS); Golden, Colorado (Data)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Stoffel, T.; Andreas, A.

    The SRRL was established at the Solar Energy Research Institute (now NREL) in 1981 to provide continuous measurements of the solar resources, outdoor calibrations of pyranometers and pyrheliometers, and to characterize commercially available instrumentation. The SRRL is an outdoor laboratory located on South Table Mountain, a mesa providing excellent solar access throughout the year, overlooking Denver. Beginning with the basic measurements of global horizontal irradiance, direct normal irradiance and diffuse horizontal irradiance at 5-minute intervals, the SRRL Baseline Measurement System now produces more than 130 data elements at 1-min intervals that are available from the Measurement & Instrumentation Data Center Web site. Data sources include global horizontal, direct normal, diffuse horizontal (from shadowband and tracking disk), global on tilted surfaces, reflected solar irradiance, ultraviolet, infrared (upwelling and downwelling), photometric and spectral radiometers, sky imagery, and surface meteorological conditions (temperature, relative humidity, barometric pressure, precipitation, snow cover, wind speed and direction at multiple levels). Data quality control and assessment include daily instrument maintenance (M-F) with automated data quality control based on real-time examinations of redundant instrumentation and internal consistency checks using NREL's SERI-QC methodology. Operators are notified of equipment problems by automatic e-mail messages generated by the data acquisition and processing system. Radiometers are recalibrated at least annually with reference instruments traceable to the World Radiometric Reference (WRR).

  17. NREL Solar Radiation Research Laboratory (SRRL): Baseline Measurement System (BMS); Golden, Colorado (Data)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Stoffel, T.; Andreas, A.

    1981-07-15

    The SRRL was established at the Solar Energy Research Institute (now NREL) in 1981 to provide continuous measurements of the solar resources, outdoor calibrations of pyranometers and pyrheliometers, and to characterize commercially available instrumentation. The SRRL is an outdoor laboratory located on South Table Mountain, a mesa providing excellent solar access throughout the year, overlooking Denver. Beginning with the basic measurements of global horizontal irradiance, direct normal irradiance and diffuse horizontal irradiance at 5-minute intervals, the SRRL Baseline Measurement System now produces more than 130 data elements at 1-min intervals that are available from the Measurement & Instrumentation Data Center Web site. Data sources include global horizontal, direct normal, diffuse horizontal (from shadowband and tracking disk), global on tilted surfaces, reflected solar irradiance, ultraviolet, infrared (upwelling and downwelling), photometric and spectral radiometers, sky imagery, and surface meteorological conditions (temperature, relative humidity, barometric pressure, precipitation, snow cover, wind speed and direction at multiple levels). Data quality control and assessment include daily instrument maintenance (M-F) with automated data quality control based on real-time examinations of redundant instrumentation and internal consistency checks using NREL's SERI-QC methodology. Operators are notified of equipment problems by automatic e-mail messages generated by the data acquisition and processing system. Radiometers are recalibrated at least annually with reference instruments traceable to the World Radiometric Reference (WRR).

  18. Markov Jump Processes Approximating a Non-Symmetric Generalized Diffusion

    SciTech Connect (OSTI)

    Limic, Nedzad

    2011-08-15

    Consider a non-symmetric generalized diffusion X( Dot-Operator ) in Double-Struck-Capital-R {sup d} determined by the differential operator A(x) = -{Sigma}{sub ij} {partial_derivative}{sub i}a{sub ij}(x){partial_derivative}{sub j} + {Sigma}{sub i} b{sub i}(x){partial_derivative}{sub i}. In this paper the diffusion process is approximated by Markov jump processes X{sub n}( Dot-Operator ), in homogeneous and isotropic grids G{sub n} Subset-Of Double-Struck-Capital-R {sup d}, which converge in distribution in the Skorokhod space D([0,{infinity}), Double-Struck-Capital-R {sup d}) to the diffusion X( Dot-Operator ). The generators of X{sub n}( Dot-Operator ) are constructed explicitly. Due to the homogeneity and isotropy of grids, the proposed method for d{>=}3 can be applied to processes for which the diffusion tensor {l_brace}a{sub ij}(x){r_brace}{sub 11}{sup dd} fulfills an additional condition. The proposed construction offers a simple method for simulation of sample paths of non-symmetric generalized diffusion. Simulations are carried out in terms of jump processes X{sub n}( Dot-Operator ). For piece-wise constant functions a{sub ij} on Double-Struck-Capital-R {sup d} and piece-wise continuous functions a{sub ij} on Double-Struck-Capital-R {sup 2} the construction and principal algorithm are described enabling an easy implementation into a computer code.

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

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

    "Phase separation and dynamic patterning in Cu1-xCox films under ion irradiation," Phys. Rev. B 72 (2005), 174102. S. Odunuga, Y. Li, P. Krasnochtchekov, P. Bellon, and R....

  20. Method for mounting laser fusion targets for irradiation

    DOE Patents [OSTI]

    Fries, R. Jay; Farnum, Eugene H.; McCall, Gene H.

    1977-07-26

    Methods for preparing laser fusion targets of the ball-and-disk type are disclosed. Such targets are suitable for irradiation with one or two laser beams to produce the requisite uniform compression of the fuel material.

  1. Carbon Characterization Laboratory Readiness to Receive Irradiated Graphite Samples

    SciTech Connect (OSTI)

    Karen A. Moore

    2011-05-01

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

  2. Flat Ge-doped optical fibres for food irradiation dosimetry

    SciTech Connect (OSTI)

    Noor, N. Mohd; Jusoh, M. A.; Razis, A. F. Abdull; Alawiah, A.; Bradley, D. A.

    2015-04-24

    Exposing food to radiation can improve hygiene quality, germination control, retard sprouting, and enhance physical attributes of the food product. To provide for food safety, radiation dosimetry in irradiated food is required. Herein, fabricated germanium doped (Ge-doped) optical fibres have been used. The fibres have been irradiated using a gamma source irradiator, doses in the range 1 kGy to 10 kGy being delivered. Using Ge-doped optical fibres of variable size, type and dopant concentration, study has been made of linearity, reproducibility, and fading. The thermoluminescence (TL) yield of the fibres were obtained and compared. The fibres exhibit a linear dose response over the investigated range of doses, with mean reproducibility to within 2.69 % to 8.77 %, exceeding the dose range of all commercial dosimeters used in evaluating high doses for the food irradiation industry. TL fading of the Ge-doped flat fibres has been found to be < 13%.

  3. Irradiation facilities at the Los Alamos Meson Physics Facility

    SciTech Connect (OSTI)

    Sandberg, V.

    1990-01-01

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

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

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

    S. A. Maloy, M. B. Toloczko, K. J. McClellan, T. Romero, Y. Kohno, F. A. Garner, R. J. Kurtz, and A. Kimura, "The effects of fast reactor irradiation conditions on the tensile ...

  5. FATIGUE LIFE PREDICTION FOR STEELS IN PULSATING IRRADIATED SYSTEMS

    Office of Scientific and Technical Information (OSTI)

    (Technical Report) | SciTech Connect Technical Report: FATIGUE LIFE PREDICTION FOR STEELS IN PULSATING IRRADIATED SYSTEMS Citation Details In-Document Search Title: FATIGUE LIFE PREDICTION FOR STEELS IN PULSATING IRRADIATED SYSTEMS Authors: Farmer, J C ; Kramer, K J ; Williams, D J Publication Date: 2012-04-29 OSTI Identifier: 1082417 Report Number(s): LLNL-TR-554731 DOE Contract Number: W-7405-ENG-48 Resource Type: Technical Report Research Org: Lawrence Livermore National Laboratory

  6. 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 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 tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  7. 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 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 tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  8. 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 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 tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  9. 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 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 tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  10. Improved Solar Power Plant Efficiency: Low Cost Solar Irradiance Sensor -

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

    Energy Innovation Portal Solar Photovoltaic Solar Photovoltaic Industrial Technologies Industrial Technologies Electricity Transmission Electricity Transmission Find More Like This Return to Search Improved Solar Power Plant Efficiency: Low Cost Solar Irradiance Sensor University of Colorado Contact CU About This Technology Publications: PDF Document Publication CU3117D (Irradiance Sensor) Marketing Summary.pdf (149 KB) Technology Marketing Summary A University of Colorado research group led

  11. Ion irradiation testing of Improved Accident Tolerant Cladding Materials

    SciTech Connect (OSTI)

    Anderoglu, Osman; Tesmer, Joseph R.; Maloy, Stuart A.

    2014-01-14

    This report summarizes the results of ion irradiations conducted on two FeCrAl alloys (named as ORNL A&B) for improving the accident tolerance of LWR nuclear fuel cladding. After irradiation with 1.5 MeV protons to ~0.5 to ~1 dpa and 300°C nanoindentations were performed on the cross-sections along the ion range. An increase in hardness was observed in both alloys. Microstructural analysis shows radiation induced defects.

  12. Measuring Broadband IR Irradiance in the Direct Solar Beam (Poster)

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Poster) Citation Details In-Document Search Title: Measuring Broadband IR Irradiance in the Direct Solar Beam (Poster) Solar and atmospheric science radiometers, e.g. pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference, which is maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, developed to measure extended broadband direct solar irradiance beyond the

  13. Measuring Broadband IR Irradiance in the Direct Solar Beam (Presentation)

    Office of Scientific and Technical Information (OSTI)

    (Conference) | SciTech Connect Presentation) Citation Details In-Document Search Title: Measuring Broadband IR Irradiance in the Direct Solar Beam (Presentation) Solar and atmospheric science radiometers, e.g. pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to a consensus reference, which is maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, developed to measure extended broadband direct solar irradiance beyond

  14. Molecular Weight Distributions of Irradiated Siloxane-Based Elastomers: A

    Office of Scientific and Technical Information (OSTI)

    Complementary Study by Statistical Modeling and Multiple Quantum Nuclear Magnetic Resonance. (Journal Article) | SciTech Connect Molecular Weight Distributions of Irradiated Siloxane-Based Elastomers: A Complementary Study by Statistical Modeling and Multiple Quantum Nuclear Magnetic Resonance. Citation Details In-Document Search Title: Molecular Weight Distributions of Irradiated Siloxane-Based Elastomers: A Complementary Study by Statistical Modeling and Multiple Quantum Nuclear Magnetic

  15. Stress/Strain Response of Irradiated Metallic Materials via Spherical

    Office of Scientific and Technical Information (OSTI)

    Nanoindentation (Conference) | SciTech Connect Conference: Stress/Strain Response of Irradiated Metallic Materials via Spherical Nanoindentation Citation Details In-Document Search Title: Stress/Strain Response of Irradiated Metallic Materials via Spherical Nanoindentation Authors: Pathak, Siddhartha [1] ; Mara, Nathan Allan [1] ; Kalidindi, Surya [2] ; Wang, Yongqiang [1] ; Doerner, Russ [3] ; Nelson, Andrew Thomas [1] + Show Author Affiliations Los Alamos National Laboratory Georgia Tech

  16. Thermoluminescence and dielectric response of gamma irradiated muscovite mica

    SciTech Connect (OSTI)

    Kaur, Sukhnandan Singh, Surinder Singh, Lakhwant; Lochab, S. P.

    2014-04-24

    The effect of gamma radiation dose on the thermoluminescence (TL) and dielectric properties of muscovite mica was studied. TL glow curves exhibited a single peak around 141 {sup 0}C and its activation energy was estimated to be about 0.89 eV. Different dielectric parameters like dielectric constant, dielectric loss and ac conductivity have been calculated in both pristine and gamma irradiated samples. These dielectric parameters have been studied as a function of irradiation dose.

  17. US RERTR FUEL DEVELOPMENT POST IRRADIATION EXAMINATION RESULTS

    SciTech Connect (OSTI)

    A. B. Robinson; D. M. Wachs; D. E. Burkes; D. D. Keiser

    2008-10-01

    Post irradiation examinations of irradiated RERTR plate type fuel at the Idaho National Laboratory have led to in depth characterization of fuel behavior and performance. Both destructive and non-destructive examination capabilities at the Hot Fuels Examination Facility (HFEF) as well as recent results obtained are discussed herein. New equipment as well as more advanced techniques are also being developed to further advance the investigation into the performance of the high density U-Mo fuel.

  18. PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT

    Office of Scientific and Technical Information (OSTI)

    EXTRACTION (Conference) | SciTech Connect PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT EXTRACTION Citation Details In-Document Search Title: PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT EXTRACTION The United States Department of Energy proposes to re-establish a domestic capability for producing plutonium-238 (238Pu) to fuel radioisotope power systems primarily in support of future space missions. A conceptual design report is currently

  19. PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT

    Office of Scientific and Technical Information (OSTI)

    EXTRACTION (Conference) | SciTech Connect PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT EXTRACTION Citation Details In-Document Search Title: PLUTONIUM-238 RECOVERY FROM IRRADIATED NEPTUNIUM TARGETS USING SOLVENT EXTRACTION × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  20. Carbon dioxide laser irradiation of bacterial targets in vitro

    SciTech Connect (OSTI)

    Byrne, P.O.; Sisson, P.R.; Oliver, P.D.; Ingham, H.R.

    1987-05-01

    Agar targets seeded with Escherichia coli and Staphylococcus aureus in roll tubes simulating the vaginal vault were irradiated with a CO/sub 2/ laser at various power densities and durations. Viable bacteria were detected in the plume emissions in all instances. Staphylococcus aureus was found to be more resistant to the thermal effects of lasing than E. coli. This suggests that CO/sub 2/ irradiation of cervical lesions could disseminate viable particles which may be a hazard for patients and operators.

  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 Print 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 tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  2. 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 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 tomography, is a popular method of investigating micrometer deformation and fracture behavior in

  3. Heavy-ion irradiation induced diamond formation in carbonaceous materials.

    SciTech Connect (OSTI)

    Daulton, T. L.

    1999-01-08

    The basic mechanisms of metastable phase formation produced under highly non-equilibrium thermodynamic conditions within high-energy particle tracks are investigated. In particular, the possible formation of diamond by heavy-ion irradiation of graphite at ambient temperature is examined. This work was motivated, in part, by earlier studies which discovered nanometer-grain polycrystalline diamond aggregates of submicron-size in uranium-rich carbonaceous mineral assemblages of Precambrian age. It was proposed that the radioactive decay of uranium formed diamond in the fission particle tracks produced in the carbonaceous minerals. To test the hypothesis that nanodiamonds can form by ion irradiation, fine-grain polycrystalline graphite sheets were irradiated with 400 MeV Kr ions. The ion irradiated graphite (and unirradiated graphite control) were then subjected to acid dissolution treatments to remove the graphite and isolate any diamonds that were produced. The acid residues were then characterized by analytical and high-resolution transmission electron microscopy. The acid residues of the ion-irradiated graphite were found to contain ppm concentrations of nanodiamonds, suggesting that ion irradiation of bulk graphite at ambient temperature can produce diamond.

  4. Initiate test loop irradiations of ALSEP process solvent

    SciTech Connect (OSTI)

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

    2014-09-01

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

  5. Combined Effects of Temperature and Irradiation on Concrete Damage

    SciTech Connect (OSTI)

    Le Pape, Yann; Giorla, Alain; Sanahuja, Julien

    2016-01-01

    Aggregate radiation-induced volumetric expansion (RIVE) is a predominant mechanism in the formation of mechanical damage in the hardened cement paste (hcp) of irradiated concrete under fast-neutron flux (Giorla et al. 2015). Among the operating conditions difference between test reactors and light water reactors (LWRs), the difference of irradiation flux and temperature is significant. While a temperature increase is quite generally associated with a direct, or indirect (e.g., by dehydration) loss of mechanical properties (Maruyama et al. 2014), we found that it causes a partial annealing of irradiation amorphization of α-quartz, hence, reducing RIVE rate. Based on data collected by Bykov et al. (1981), an incremental RIVE model coupling neutron fluence and temperature is developed. The elastic properties and coefficient of thermal expansion (CTE) of irradiated polycrystalline quartz are interpreted through analytical homogenization of experimental data on irradiated α-quartz published by Mayer and Lecomte (1960). Moreover, the proposed model, implemented in the meso-scale simulation code AMIE, is compared to experimental data obtained on ordinary concrete made of quartz/quartzite aggregate (Dubrovskii et al. 1967). Substantial discrepancy, in terms of damage and volumetric expansion developments, is found when comparing irradiation scenarios assuming constant flux and temperature, as opposed to more realistic test reactor operation conditions.

  6. Combined Effects of Temperature and Irradiation on Concrete Damage

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

    Le Pape, Yann; Giorla, Alain; Sanahuja, Julien

    2016-01-01

    Aggregate radiation-induced volumetric expansion (RIVE) is a predominant mechanism in the formation of mechanical damage in the hardened cement paste (hcp) of irradiated concrete under fast-neutron flux (Giorla et al. 2015). Among the operating conditions difference between test reactors and light water reactors (LWRs), the difference of irradiation flux and temperature is significant. While a temperature increase is quite generally associated with a direct, or indirect (e.g., by dehydration) loss of mechanical properties (Maruyama et al. 2014), we found that it causes a partial annealing of irradiation amorphization of α-quartz, hence, reducing RIVE rate. Based on data collected by Bykovmore » et al. (1981), an incremental RIVE model coupling neutron fluence and temperature is developed. The elastic properties and coefficient of thermal expansion (CTE) of irradiated polycrystalline quartz are interpreted through analytical homogenization of experimental data on irradiated α-quartz published by Mayer and Lecomte (1960). Moreover, the proposed model, implemented in the meso-scale simulation code AMIE, is compared to experimental data obtained on ordinary concrete made of quartz/quartzite aggregate (Dubrovskii et al. 1967). Substantial discrepancy, in terms of damage and volumetric expansion developments, is found when comparing irradiation scenarios assuming constant flux and temperature, as opposed to more realistic test reactor operation conditions.« less

  7. Influence of irradiation upon few-layered graphene using electron-beams and gamma-rays

    SciTech Connect (OSTI)

    Wang, Yuqing; Feng, Yi, E-mail: fyhfut@163.com; Mo, Fei; Qian, Gang; Chen, Yangming; Yu, Dongbo; Wang, Yang; Zhang, Xuebin [School of Materials Science and Engineering, Hefei University of Technology, Hefei 230009 (China)

    2014-07-14

    Few-layered graphene (FLG) is irradiated by electron beams and gamma rays. After 100?keV electron irradiation, the edges of FLG start bending, shrinking, and finally generate gaps and carbon onions due to sputtering and knock-on damage mechanism. When the electron beam energy is increased further to 200?keV, FLG suffers rapid and catastrophic destruction. Unlike electron irradiation, Compton effect is the dominant damage mechanism in gamma irradiation. The irradiation results indicate the crystallinity of FLG decreases first, then restores as increasing irradiation doses, additionally, the ratio (O/C) of FLG surface and the relative content of oxygen groups increases after irradiation.

  8. The effects of tungsten's pre-irradiation surface condition on helium-irradiated morphology

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

    Garrison, Lauren M.; Kulcinski, Gerald L.

    2015-07-17

    Erosion is a concern associated with the use of tungsten as a plasma-facing component in fusion reactors. To compare the damage progression, polycrystalline tungsten (PCW) and (110) single crystal tungsten (SCW) samples were prepared with (1) a mechanical polish (MP) with roughness values in the range of 0.018–0.020 μm and (2) an MP and electropolish (MPEP) resulting in roughness values of 0.010–0.020 μm for PCW and 0.003–0.005 μm for SCW samples. Samples were irradiated with 30 keV He+ at 1173 K to fluences between 3 × 1021 and 6 × 1022 He/m2. The morphologies that developed after low-fluence bombardment weremore » different for each type of sample—MP SCW, MPEP SCW, MP PCW, and MPEP PCW. At the highest fluence, the SCW MPEP sample lost significantly more mass and developed a different morphology than the MP SCW sample. The PCW samples developed a similar morphology and had similar mass loss at the highest fluence. Surface preparation can have a significant effect on post-irradiation morphology that should be considered for the design of future fusion reactors such as ITER and DEMO.« less

  9. Irradiation-Assisted Stress Corrosion Cracking of Austenitic Stainless Steels and Alloy 690 from Halden Phase-II Irradiations

    SciTech Connect (OSTI)

    Chen, Y.; Chopra, O. K.; Soppet, W. K.; Dietz Rago, Nancy L.; Shack, W. J.

    2008-09-01

    This work is an ongoing effort at Argonne National Laboratory on the mechanistic study of irradiation-assisted stress corrosion cracking (IASCC) in the core internals of light water reactors.

  10. Delivery of completed irradiation vehicles and the quality assurance document to the High Flux Isotope Reactor for irradiation

    SciTech Connect (OSTI)

    Petrie, Christian M.; McDuffee, Joel Lee; Katoh, Yutai; Terrani, Kurt A.

    2015-10-01

    This report details the initial fabrication and delivery of two Fuel Cycle Research and Development (FCRD) irradiation capsules (ATFSC01 and ATFSC02), with associated quality assurance documentation, to the High Flux Isotope Reactor (HFIR). The capsules and documentation were delivered by September 30, 2015, thus meeting the deadline for milestone M3FT-15OR0202268. These irradiation experiments are testing silicon carbide composite tubes in order to obtain experimental validation of thermo-mechanical models of stress states in SiC cladding irradiated under a prototypic high heat flux. This document contains a copy of the completed capsule fabrication request sheets, which detail all constituent components, pertinent drawings, etc., along with a detailed summary of the capsule assembly process performed by the Thermal Hydraulics and Irradiation Engineering Group (THIEG) in the Reactor and Nuclear Systems Division (RNSD). A complete fabrication package record is maintained by the THIEG and is available upon request.

  11. Solar spectral irradiance changes during cycle 24

    SciTech Connect (OSTI)

    Marchenko, S. V.; DeLand, M. T.

    2014-07-10

    We use solar spectra obtained by the Ozone Monitoring Instrument (OMI) on board the Aura satellite to detect and follow long-term (years) and short-term (weeks) changes in the solar spectral irradiance (SSI) in the 265-500 nm spectral range. During solar Cycle 24, in the relatively line-free regions the SSI changed by ?0.6% 0.2% around 265 nm. These changes gradually diminish to 0.15% 0.20% at 500 nm. All strong spectral lines and blends, with the notable exception of the upper Balmer lines, vary in unison with the solar 'continuum'. Besides the lines with strong chromospheric components, the most involved species include Fe I blends and all prominent CH, NH, and CN spectral bands. Following the general trend seen in the solar 'continuum', the variability of spectral lines also decreases toward longer wavelengths. The long-term solar cycle SSI changes are closely, to within the quoted 0.1%-0.2% uncertainties, matched by the appropriately adjusted short-term SSI variations derived from the 27 day rotational modulation cycles. This further strengthens and broadens the prevailing notion about the general scalability of the UV SSI variability to the emissivity changes in the Mg II 280 nm doublet on timescales from weeks to years. We also detect subtle deviations from this general rule: the prominent spectral lines and blends at ? ? 350 nm show slightly more pronounced 27 day SSI changes when compared to the long-term (years) trends. We merge the solar data from Cycle 21 with the current Cycle 24 OMI and GOME-2 observations and provide normalized SSI variations for the 170-795 nm spectral region.

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

    SciTech Connect (OSTI)

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

    1997-04-01

    Three ferritic alloys were irradiated in two fast reactors to doses of 50 dpa or more at temperatures near 400{degrees}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{degrees}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 x 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. Atomic Scale Modelling of the Primary Damage State of Irradiated UO{sub 2} Matrix

    SciTech Connect (OSTI)

    Van Brutzel, Laurent

    2008-07-01

    Large scale classical molecular dynamics simulations have been carried out to study the primary damage state due to a-decay self irradiation in UO{sub 2} matrix. Simulations of energetic displacement cascades up to the realistic energy of the recoil nucleus at 80 keV provide new informations on defect production, their spatial distribution and their clustering. The discrepancy with the classical linear theory NRT (Norton-Robinson-Torrens) law on the creation of the number of point defects is discussed. Study of cascade overlap sequence shows a saturation of the number of point defects created as the dose increases. Toward the end of the overlap sequence, large stable clusters of vacancies are observed. The values of athermal diffusion coefficients coming from the ballistic collisions and the additional point defects created during the cascades are estimated from these simulations to be, in all the cases, less than 10-26 m{sup 2}/s. Finally, the influence of a grain boundary of type Sigma 5 is analysed. It has been found that the energy of the cascades are dissipated along the interface and that most of the point defects are created at the grain boundary. (authors)

  14. Simulation of X-ray Irradiation on Optics and Chamber Wall Materials for Inertial Fusion Energy

    SciTech Connect (OSTI)

    Reyes, S; Latkowski, J F; Abbott, R P; Stein, W

    2003-09-10

    We have used the ABLATOR code to analyze the effect of the x-ray emission from direct drive targets on the optics and the first wall of a conceptual laser Inertial Fusion Energy (IFE) power plant. For this purpose, the ABLATOR code has been modified to incorporate the predicted x-ray spectrum from a generic direct drive target. We have also introduced elongation calculations in ABLATOR to predict the thermal stresses in the optic and first wall materials. These results have been validated with thermal diffusion calculations, using the LLNL heat transfer and dynamic structural finite element codes Topaz3d and Dyna3d. One of the most relevant upgrades performed in the ABLATOR code consists of the possibility to accommodate multi-material simulations. This new feature allows for a more realistic modeling of typical IFE optics and first wall materials, which may have a number of different layers. Finally, we have used the XAPPER facility, at LLNL, to develop our predictive capability and validate the results. The ABLATOR code will be further modified, as necessary, to predict the effects of x-ray irradiation in both the IFE real case and our experiments on the XAPPER facility.

  15. In situ carbonyl extraction of Ni from gaseous diffusion cells

    SciTech Connect (OSTI)

    Visnapuu, A. [USBM Salt Lake Research Center, Salt Lake City, UT (United States); Hollenberg, G.W. [Battelle Pacific Northwest Lab., Richland, WA (United States); Bundy, R.D. [Battelle Memorial Institute, Oak Ridge, TN (United States)

    1995-12-31

    This paper discusses the use of carbonyl processing technology for recovery of nickel from uranium isotope separation diffusion cells, and potential applications to recover nickel, iron, chromium, cobalt, and other carbonyl forming metals from nuclear waste while reducing the volume of the high level residue for more economic disposal. Nickel powder was carbonylated under static and dynamic conditions using only carbon monoxide to determine if the nickel powder would react rapidly enough to require no promoter. Nickel to Ni(CO){sub 4} conversion was realized in all cases and nickel metal was vapor deposited in the thermal decomposer, but the conversion rates in all cases the reaction were too slow for practical recovery. Addition of hydrogen sulfide gas as a promoter increased the conversion rate more than 500-fold over conversion with no promoter. Test summaries are provided in the paper; results indicate that promoter activated carbonylation is a viable approach for recovery of nickel from uranium isotope diffusion cells.

  16. Complex statistics and diffusion in nonlinear disordered particle chains

    SciTech Connect (OSTI)

    Antonopoulos, Ch. G.; Bountis, T.; Skokos, Ch.; Drossos, L.

    2014-06-15

    We investigate dynamically and statistically diffusive motion in a Klein-Gordon particle chain in the presence of disorder. In particular, we examine a low energy (subdiffusive) and a higher energy (self-trapping) case and verify that subdiffusive spreading is always observed. We then carry out a statistical analysis of the motion, in both cases, in the sense of the Central Limit Theorem and present evidence of different chaos behaviors, for various groups of particles. Integrating the equations of motion for times as long as 10{sup 9}, our probability distribution functions always tend to Gaussians and show that the dynamics does not relax onto a quasi-periodic Kolmogorov-Arnold-Moser torus and that diffusion continues to spread chaotically for arbitrarily long times.

  17. Paducah Gaseous Diffusion Plant environmental report for 1992

    SciTech Connect (OSTI)

    Horak, C.M.

    1993-09-01

    This two-part report, Paducah Gaseous Diffusion Plant Environmental Report for 1992, is published annually. It reflects the results of an environmental monitoring program designed to quantify potential increases in the concentration of contaminants and potential doses to the resident human population. The Paducah Gaseous Diffusion Plant (PGDP) overall goal for environmental management is to protect the environment and PGDP`s neighbors and to maintain full compliance with all current regulations. The current environmental strategy is to identify any deficiencies and to develop a system to resolve them. The long-range goal of environmental management is to minimize the source of pollutants, reduce the generation of waste, and minimize hazardous waste by substitution of materials.

  18. Paducah Gaseous Diffusion Plant Environmental report for 1990

    SciTech Connect (OSTI)

    Counce-Brown, D.

    1991-09-01

    This two-part report, Paducah Gaseous Diffusion Plant Site Environmental Report for 1990, is published annually. It reflects the results of a comprehensive, year-round program to monitor the impact of operations at Paducah Gaseous Diffusion Plant (PGDP) on the area's groundwater and surface waters, soil, air quality, vegetation, and wildlife. In addition, an assessment of the effect of PGDP effluents on the resident human population is made. PGDP's overall goal for environmental management is to protect the environment and PGDP's neighbors and to maintain full compliance with all current regulations. The current environmental strategy is to identify any deficiencies and to develop a system to resolve them. The long-range goal of environmental management is to minimize the source of pollutants, to reduce the formation of waste, and to minimize hazardous waste by substitution of materials.

  19. GALEX DIFFUSE OBSERVATIONS OF THE SKY: THE DATA

    SciTech Connect (OSTI)

    Murthy, Jayant

    2014-08-01

    I present tabulations of the diffuse observations made by the GALEX spacecraft in two UV bands (FUV: 1539 and NUV: 2316 ) from the (almost) final data release of the GALEX spacecraft (GR6/GR7). This data release includes all the FUV observations and the majority of the NUV observations. I discuss overall trends in the data but the primary purpose of this paper is to make the data available to the public. The data files described in this paper are hosted by the Mikulski Archive for Space Telescopes at the Space Telescope Science Insitute from whence they may be downloaded. For ease of use, I have also created maps of the diffuse radiation in both bands over the entire observed sky at 6' resolution.

  20. Ligand-gated Diffusion Across the Bacterial Outer Membrane

    SciTech Connect (OSTI)

    B Lepore; M Indic; H Pham; E Hearn; D Patel; B van den Berg

    2011-12-31

    Ligand-gated channels, in which a substrate transport pathway is formed as a result of the binding of a small-molecule chemical messenger, constitute a diverse class of membrane proteins with important functions in prokaryotic and eukaryotic organisms. Despite their widespread nature, no ligand-gated channels have yet been found within the outer membrane (OM) of Gram-negative bacteria. Here we show, using in vivo transport assays, intrinsic tryptophan fluorescence and X-ray crystallography, that high-affinity (submicromolar) substrate binding to the OM long-chain fatty acid transporter FadL from Escherichia coli causes conformational changes in the N terminus that open up a channel for substrate diffusion. The OM long-chain fatty acid transporter FadL from E. coli is a unique paradigm for OM diffusion-driven transport, in which ligand gating within a {beta}-barrel membrane protein is a prerequisite for channel formation.

  1. Dye laser amplifier including a specifically designed diffuser assembly

    DOE Patents [OSTI]

    Davin, James; Johnston, James P.

    1992-01-01

    A large (high flow rate) dye laser amplifier in which a continuous replened supply of dye is excited by a first light beam, specifically a copper vapor laser beam, in order to amplify the intensity of a second different light beam, specifically a dye beam, passing through the dye is disclosed herein. This amplifier includes a dye cell defining a dye chamber through which a continuous stream of dye is caused to pass at a relatively high flow rate and a specifically designed diffuser assembly for slowing down the flow of dye while, at the same time, assuring that as the dye stream flows through the diffuser assembly it does so in a stable manner.

  2. Ulcerative colitis and steroid-responsive, diffuse interstitial lung disease

    SciTech Connect (OSTI)

    Balestra, D.J.; Balestra, S.T.; Wasson, J.H.

    1988-07-01

    The authors describe a patient with ulcerative colitis and extracolonic manifestations in whom diffuse interstitial pulmonary disease developed that was responsive to glucocorticoid therapy one year after total proctocolectomy. The patient presented in December 1983 with a subacute course marked by cough and progressive exertional dyspnea, abnormal chest examination results, and a chest roentgenogram that revealed diffuse interstitital and alveolar infiltrates. A transbronchial biopsy specimen revealed a polymorphic interstitial infiltrate, mild interstitial fibrosis without apparent intraluminal fibrosis, and no vasculitis, granulomas, or significant eosinophilic infiltration. Within one week of the initiation of daily high-dose steroid therapy, the patient's symptoms dramatically improved; chest roentgenogram and forced vital capacity (60%) improved at a slower rate. All three measures deteriorated when alternate-day prednisone therapy was started but once again improved until the patient was totally asymptomatic, chest roentgenograms were normal, and forced vital capacity was 80% of the predicted value 2 1/2 years later.

  3. Palladium diffusion into bulk copper via the (100) surface.

    SciTech Connect (OSTI)

    Bussmann, Ezra; Pohl, Karsten; Sun, Jiebing; Kellogg, Gary Lee

    2009-01-01

    Using low-energy electron microscopy, we measure the diffusion of Pd into bulk Cu at the Cu(100) surface. Interdiffusion is tracked by measuring the dissolution of the Cu(100)-c(2 x 2)-Pd surface alloy during annealing (T > 240 C). The activation barrier for Pd diffusion from the surface alloy into the bulk is determined to be (1.8 {+-} 0.6) eV. During annealing, we observe the growth of a new layer of Cu near step edges. Under this new Cu layer, dilute Pd remaining near the surface develops a layered structure similar to the Cu{sub 3}Pd L 1{sub 2} bulk alloy phase.

  4. A 2D Radiation Transport Package with Mimetic Diffusion for ExaFlag...

    Office of Scientific and Technical Information (OSTI)

    A 2D Radiation Transport Package with Mimetic Diffusion for ExaFlag Citation Details In-Document Search Title: A 2D Radiation Transport Package with Mimetic Diffusion for ExaFlag...

  5. Origin of Novel Diffusions of Cu and Ag in Semiconductors: The...

    Office of Scientific and Technical Information (OSTI)

    Origin of Novel Diffusions of Cu and Ag in Semiconductors: The Case of CdTe Prev Next Title: Origin of Novel Diffusions of Cu and Ag in Semiconductors: The Case of CdTe ...

  6. Kenya Hourly DNI, GHI and Diffuse Solar Data - Datasets - OpenEI...

    Open Energy Info (EERE)

    Kenya Hourly DNI, GHI and Diffuse Solar Data Abstract Each data file is a set of hourly values of solar radiation (DNI, GHI and diffuse) and meteorological elements for a 1-year...

  7. The Structural Evolution and Diffusion During the Chemical Transformation

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

    from Cobalt to Cobalt Phosphide Nanoparticles > Research Highlights > Research > The Energy Materials Center at Cornell Research Highlights In This Section The Structural Evolution and Diffusion During the Chemical Transformation from Cobalt to Cobalt Phosphide Nanoparticles Joint Density-Functional Theory of Electrochemistry Double-band Electrode Channel Flow DEMS Cell Sulfur@Carbon Cathodes for Lithium Sulfur Batteries Better Ham & Cheese: Enhanced Anodes and Cathodes for Fuel

  8. Federal Facility Agreement for the Paducah Gaseous Diffusion Plant Summary

    Office of Environmental Management (EM)

    Federal Facility Agreement for the Paducah Gaseous Diffusion Plant State Kentucky Agreement Type Federal Facility Agreement Legal Driver(s) CERCLA/RCRA Scope Summary Ensure that the environmental impacts of activities at the Site are investigated and appropriate response actions are taken. Parties U.S. DOE; Kentucky Natural Resources and Environmental Protection Cabinet; U.S. EPA Date 2/01/1998 SCOPE * Ensure all releases of hazardous substances, pollutants, or contaminants are addressed to

  9. Real Space Mapping of Oxygen Vacancy Diffusion and Electrochemical

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

    Transformations by Hysteretic Current Reversal Curve Measurements - Energy Innovation Portal Hydrogen and Fuel Cell Hydrogen and Fuel Cell Energy Storage Energy Storage Find More Like This Return to Search Real Space Mapping of Oxygen Vacancy Diffusion and Electrochemical Transformations by Hysteretic Current Reversal Curve Measurements Oak Ridge National Laboratory Contact ORNL About This Technology Technology Marketing SummaryElectrochemical energy storage and conversion systems based on

  10. Method of making gas diffusion layers for electrochemical cells

    DOE Patents [OSTI]

    Frisk, Joseph William; Boand, Wayne Meredith; Larson, James Michael

    2002-01-01

    A method is provided for making a gas diffusion layer for an electrochemical cell comprising the steps of: a) combining carbon particles and one or more surfactants in a typically aqueous vehicle to make a preliminary composition, typically by high shear mixing; b) adding one or more highly fluorinated polymers to said preliminary composition by low shear mixing to make a coating composition; and c) applying the coating composition to an electrically conductive porous substrate, typically by a low shear coating method.

  11. 1,2,3-D Diffusion Depletion Multi-Group

    Energy Science and Technology Software Center (OSTI)

    1992-04-20

    CITATION is designed to solve problems using the finite difference representation of neutron diffusion theory, treating up to three space dimensions with arbitrary group to group scattering. X-y-z, theta-r-z, hexagonal z, and triagonal z geometries may be treated. Depletion problems may be solved and fuel managed for multi-cycle analysis. Extensive first order perturbation results may be obtained given microscopic data and nuclide concentrations. Statics problems may be solved and perturbation results obtained with microscopic data.

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

    SciTech Connect (OSTI)

    Clark, E.

    2013-09-13

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

  13. Tracer diffusion in compacted, water-saturated bentonite

    SciTech Connect (OSTI)

    Bourg, Ian C.; Sposito, Garrison; Bourg, Alain C.M.

    2005-08-04

    Compacted Na-bentonite clay barriers, widely used in theisolation of solid-waste landfills and other contaminated sites, havebeen proposed for a similar use in the disposal of high-level radioactivewaste. Molecular diffusion through the pore space in these barriers playsa key role in their performance, thus motivating recent measurements ofthe apparent diffusion coefficient tensor of water tracers in compacted,water-saturated Na-bentonites. In the present study, we introduce aconceptual model in which the pore space of water-saturated bentonite isdivided into 'macropore' and 'interlayer nanopore' compartments. Withthis model we determine quantitatively the relative contributions ofpore-network geometry (expressed as a geometric factor) and of thediffusive behavior of water molecules near montmorillonite basal surfaces(expressed as a contristivity factor) to the apparent diffusioncoefficient tensor. Our model predicts, in agreement with experiment,that the mean principal value of the apparent diffusion coefficienttensor follows a single relationship when plotted against the partialmontmorillonite dry density (mass of montmorillonite per combined volumeof montmorillonite and pore space). Using a single fitted parameter, themean principal geometric factor, our model successfully describes thisrelationship for a broad range of bentonite-water system, from dilute gelto highly-compacted bentonite with 80 percent of its pore water ininterlayer nanopores.

  14. SNOW LINES AS PROBES OF TURBULENT DIFFUSION IN PROTOPLANETARY DISKS

    SciTech Connect (OSTI)

    Owen, James E. [Canadian Institute for Theoretical Astrophysics, 60 St George Street, Toronto, M5S 3H8, ON (Canada)

    2014-07-20

    Sharp chemical discontinuities can occur in protoplanetary disks, particularly at ''snow lines'' where a gas-phase species freezes out to form ice grains. Such sharp discontinuities will diffuse out due to the turbulence suspected to drive angular momentum transport in accretion disks. We demonstrate that the concentration gradientin the vicinity of the snow lineof a species present outside a snow line but destroyed inside is strongly sensitive to the level of turbulent diffusion (provided the chemical and transport timescales are decoupled) and provides a direct measurement of the radial ''Schmidt number'' (the ratio of the angular momentum transport to radial turbulent diffusion). Taking as an example the tracer species N{sub 2}H{sup +}, which is expected to be destroyed inside the CO snow line (as recently observed in TW Hya) we show that ALMA observations possess significant angular resolution to constrain the Schmidt number. Since different turbulent driving mechanisms predict different Schmidt numbers, a direct measurement of the Schmidt number in accretion disks would allow inferences to be made about the nature of the turbulence.

  15. IUTAM symposium on hydrodynamic diffusion of suspended particles

    SciTech Connect (OSTI)

    Davis, R.H.

    1995-12-31

    Hydrodynamic diffusion refers to the fluctuating motion of nonBrownian particles (or droplets or bubbles) which occurs in a dispersion due to multiparticle interactions. For example, in a concentrated sheared suspension, particles do not move along streamlines but instead exhibit fluctuating motions as they tumble around each other. This leads to a net migration of particles down gradients in particle concentration and in shear rate, due to the higher frequency of encounters of a test particle with other particles on the side of the test particle which has higher concentration or shear rate. As another example, suspended particles subject to sedimentation, centrifugation, or fluidization, do not generally move relative to the fluid with a constant velocity, but instead experience diffusion-like fluctuations in velocity due to interactions with neighboring particles and the resulting variation in the microstructure or configuration of the suspended particles. In flowing granular materials, the particles interact through direct collisions or contacts (rather than through the surrounding fluid); these collisions also cause the particles to undergo fluctuating motions characteristic of diffusion processes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  16. Roles of carbon diffusion and step structure on the growth of...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 36 MATERIALS SCIENCE; ATOMIC FORCE MICROSCOPY; CARBON; DIFFUSION; ELECTRON MICROSCOPY; MORPHOLOGY; SUBLIMATION; ...

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

    SciTech Connect (OSTI)

    Blaise, Collin

    2014-07-01

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

  18. Preliminary analysis of results of a mountain area atmospheric diffusion test

    SciTech Connect (OSTI)

    Not Available

    1983-12-01

    The results of diffusion test of artificial smoke clouds and neutron activated smoke were used to calculate the atmospheric diffusion parameters especially focusing on the differences of the diffusion diluting capabilities of the pollutants and comparing them with related foreign results where upon useful results were obtained.

  19. Glass diffusion source for constraining BSF region of a solar cell

    DOE Patents [OSTI]

    Lesk, I.A.; Pryor, R.A.; Coleman, M.G.

    1982-08-27

    The present invention is directed to a method of fabricating a solar cell comprising simultaneous diffusion of the p and n dopant materials into the solar cell substrate. The simultaneous diffusion process is preceded by deposition of a capping layer impervious to doping by thermal diffusion processes.

  20. Diffuse γ-ray emission from galactic pulsars

    SciTech Connect (OSTI)

    Calore, F.; Di Mauro, M.; Donato, F. E-mail: mattia.dimauro@to.infn.it

    2014-11-20

    Millisecond pulsars (MSPs) are old fast-spinning neutron stars that represent the second most abundant source population discovered by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi). As guaranteed γ-ray emitters, they might contribute non-negligibly to the diffuse emission measured at high latitudes by Fermi-LAT (i.e., the Isotropic Diffuse γ-Ray Background (IDGRB)), which is believed to arise from the superposition of several components of galactic and extragalactic origin. Additionally, γ-ray sources also contribute to the anisotropy of the IDGRB measured on small scales by Fermi-LAT. In this manuscript we aim to assess the contribution of the unresolved counterpart of the detected MSPs population to the IDGRB and the maximal fraction of the measured anisotropy produced by this source class. To this end, we model the MSPs' spatial distribution in the Galaxy and the γ-ray emission parameters by considering observational constraints coming from the Australia Telescope National Facility pulsar catalog and the Second Fermi-LAT Catalog of γ-ray pulsars. By simulating a large number of MSP populations through a Monte Carlo simulation, we compute the average diffuse emission and the anisotropy 1σ upper limit. We find that the emission from unresolved MSPs at 2 GeV, where the peak of the spectrum is located, is at most 0.9% of the measured IDGRB above 10° in latitude. The 1σ upper limit on the angular power for unresolved MSP sources turns out to be about a factor of 60 smaller than Fermi-LAT measurements above 30°. Our results indicate that this galactic source class represents a negligible contributor to the high-latitude γ-ray sky and confirm that most of the intensity and geometrical properties of the measured diffuse emission are imputable to other extragalactic source classes (e.g., blazars, misaligned active galactic nuclei, or star-forming galaxies). Nevertheless, because MSPs are more concentrated toward the galactic center, we expect them to contribute significantly to the γ-ray diffuse emission at low latitudes. Because, along the galactic disk, the population of young pulsars overcomes in number that of MSPs, we compute the γ-ray emission from the whole population of unresolved pulsars, both young and millisecond, in two low-latitude regions: the inner Galaxy and the galactic center.