Sample records for fission track evidence

  1. Fission track evidence for widespread early to Middle miocene...

    Open Energy Info (EERE)

    and Range province Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: Fission track evidence for widespread early to Middle miocene...

  2. Phanerozoic tectonothermal history of the ArabianNubian shield in the Eastern Desert of Egypt: evidence from fission track

    E-Print Network [OSTI]

    Fritz, Harald

    Phanerozoic tectonothermal history of the Arabian­Nubian shield in the Eastern Desert of Egypt were performed in the Eastern Desert of Egypt. The results provide insights into the processes driving reserved. Keywords: Phanerozoic; Fission track thermochronology; Palaeostress; Arabian­Nubien shield; Egypt

  3. The spark counting of etched fission-fragment tracks in polycarbonate for a personal neutron dosimetry system

    E-Print Network [OSTI]

    Harrison, K G; Holt, P D; Wylie, J W

    1977-01-01T23:59:59.000Z

    The spark counting of etched fission-fragment tracks in polycarbonate for a personal neutron dosimetry system

  4. Improved zircon fission-track annealing model based on reevaluation of annealing data

    SciTech Connect (OSTI)

    Guedes, Sandro [Instituto de Fisica Gleb Wataghin, Unicamp, Brazil; Moreira, Pedro A.F.P. [Universidade Estadual de Campinas, Sao Paulo; Devanathan, Ram [Pacific Northwest National Laboratory (PNNL); Weber, William J [ORNL; Hadler, Julio C [Instituto de Fisica Gleb Wataghin, Unicamp, Brazil

    2013-01-01T23:59:59.000Z

    The thermal recovery (annealing) of mineral structure modified by the passage of fission fragments has long been studied by the etching technique. In minerals like apatite and zircon, the annealing kinetics are fairly well constrained from the hour to the million-year timescale and have been described by empirical and semi-empirical equations. On the other hand, laboratory experiments, in which ion beams interact with minerals and synthetic ceramics, have shown that there is a threshold temperature beyond which thermal recovery impedes ion-induced amorphization. In this work, it is assumed that this behavior can be extended to the annealing of fission tracks in minerals. It is proposed that there is a threshold temperature, T0, beyond which fission tracks are erased within a time t0, which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t vs. 1/T). Based on the proposed hypothesis, and laboratory and geological data, annealing equations are reevaluated. The geological timescale estimations of a model arising from this study are discussed through the calculation of partial annealing zone and closure temperature, and comparison with geological sample constraints found in literature. It is shown that the predictions given by this model are closer to field data on closure temperature and partial annealing zone than predictions given by previous models.

  5. Improved zircon fission-track annealing model based on reevaluation of annealing data

    SciTech Connect (OSTI)

    Guedes, S.; Moreira, Pedro; Devanathan, Ramaswami; Weber, William J.; Hadler, J. C.

    2013-02-01T23:59:59.000Z

    The thermal recovery (annealing) of mineral structure modified by the passage of fission fragments has long been studied by the etching technique. In minerals like apatite and zircon, the annealing kinetics are fairly well constrained from the hour to the million-year timescale and have been described by empirical and semi-empirical equations. On the other hand, laboratory experiments, in which ion beams interact with minerals and synthetic ceramics, have shown that there is a threshold temperature beyond which thermal recovery impedes ion-induced amorphization. In this work, it is assumed that this behavior can be extended to the annealing of fission tracks in minerals. It is proposed that there is a threshold temperature, T 0, beyond which fission tracks are erased within a time t 0, which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t vs. 1/T). Based on the proposed hypothesis, and laboratory and geological data, annealing equations are reevaluated. The geological timescale estimations of a model arising from this study are discussed through the calculation of partial annealing zone and closure temperature, and comparison with geological sample constraints found in literature. It is shown that the predictions given by this model are closer to field data on closure temperature and partial annealing zone than predictions given by previous models.

  6. Evidence for Conical Intersection Dynamics Mediating Ultrafast Singlet Exciton Fission

    E-Print Network [OSTI]

    Musser, Andrew J.; Liebel, Matz; Schnedermann, Christoph; Wende, Torsten; Kehoe, Tom B.; Rao, Akshay; Kukura, Philipp

    2015-01-01T23:59:59.000Z

    -Queisser limit for single-junction solar cells. By converting high-energy photons into two low-energy excited states, singlet fission offers a means to overcome thermalisation losses. Devices based on pentacene, a fission sensitiser, have demonstrated external... ), which aligns with the ground-state bleach (GSB) peaks in the middle of the spectrum. b Early-time dynamics from panel a. The initial stimulated emission at 700 nm decays to yield triplets with excited state absorption bands at 520 nm and 820 nm, which...

  7. Terracentric Nuclear Fission Reactor: Background, Basis, Feasibility, Structure, Evidence, and Geophysical Implications

    E-Print Network [OSTI]

    J. Marvin Herndon

    2013-12-31T23:59:59.000Z

    The background, basis, feasibility, structure, evidence, and geophysical implications of a naturally occurring Terracentric nuclear fission georeactor are reviewed. For a nuclear fission reactor to exist at the center of the Earth, all of the following conditions must be met: (1) There must originally have been a substantial quantity of uranium within Earth's core; (2) There must be a natural mechanism for concentrating the uranium; (3) The isotopic composition of the uranium at the onset of fission must be appropriate to sustain a nuclear fission chain reaction; (4) The reactor must be able to breed a sufficient quantity of fissile nuclides to permit operation over the lifetime of Earth to the present; (5) There must be a natural mechanism for the removal of fission products; (6) There must be a natural mechanism for removing heat from the reactor; (7) There must be a natural mechanism to regulate reactor power level, and; (8) The location of the reactor or must be such as to provide containment and prevent meltdown. Herndon's georeactor alone is shown to meet those conditions. Georeactor existence evidence based upon helium measurements and upon antineutrino measurements is described. Geophysical implications discussed include georeactor origin of the geomagnetic field, geomagnetic reversals from intense solar outbursts and severe Earth trauma, as well as georeactor heat contributions to global dynamics.

  8. Terracentric Nuclear Fission Reactor: Background, Basis, Feasibility, Structure, Evidence, and Geophysical Implications

    E-Print Network [OSTI]

    Herndon, J Marvin

    2013-01-01T23:59:59.000Z

    The background, basis, feasibility, structure, evidence, and geophysical implications of a naturally occurring Terracentric nuclear fission georeactor are reviewed. For a nuclear fission reactor to exist at the center of the Earth, all of the following conditions must be met: (1) There must originally have been a substantial quantity of uranium within Earth's core; (2) There must be a natural mechanism for concentrating the uranium; (3) The isotopic composition of the uranium at the onset of fission must be appropriate to sustain a nuclear fission chain reaction; (4) The reactor must be able to breed a sufficient quantity of fissile nuclides to permit operation over the lifetime of Earth to the present; (5) There must be a natural mechanism for the removal of fission products; (6) There must be a natural mechanism for removing heat from the reactor; (7) There must be a natural mechanism to regulate reactor power level, and; (8) The location of the reactor or must be such as to provide containment and prevent ...

  9. Laboratory-Scale Bismuth Phosphate Extraction Process Simulation To Track Fate of Fission Products

    SciTech Connect (OSTI)

    Serne, R. JEFFREY; Lindberg, Michael J.; Jones, Thomas E.; Schaef, Herbert T.; Krupka, Kenneth M.

    2007-02-28T23:59:59.000Z

    Recent field investigation that collected and characterized vadose zone sediments from beneath inactive liquid disposal facilities at the Hanford 200 Areas show lower than expected concentrations of a long-term risk driver, Tc-99. Therefore laboratory studies were performed to re-create one of the three processes that were used to separate the plutonium from spent fuel and that created most of the wastes disposed or currently stored in tanks at Hanford. The laboratory simulations were used to compare with current estimates based mainly on flow sheet estimates and spotty historical data. Three simulations of the bismuth phosphate precipitation process show that less that 1% of the Tc-99, Cs-135/137, Sr-90, I-129 carry down with the Pu product and thus these isotopes should have remained within the metals waste streams that after neutralization were sent to single shell tanks. Conversely, these isotopes should not be expected to be found in the first and subsequent cycle waste streams that went to cribs. Measurable quantities (~20 to 30%) of the lanthanides, yttrium, and trivalent actinides (Am and Cm) do precipitate with the Pu product, which is higher than the 10% estimate made for current inventory projections. Surprisingly, Se (added as selenate form) also shows about 10% association with the Pu/bismuth phosphate solids. We speculate that the incorporation of some Se into the bismuth phosphate precipitate is caused by selenate substitution into crystal lattice sites for the phosphate. The bulk of the U daughter product Th-234 and Np-237 daughter product Pa-233 also associate with the solids. We suspect that the Pa daughter products of U (Pa-234 and Pa-231) would also co-precipitate with the bismuth phosphate induced solids. No more than 1 % of the Sr-90 and Sb-125 should carry down with the Pu product that ultimately was purified. Thus the current scheme used to estimate where fission products end up being disposed overestimates by one order of magnitude the partitioning Sr-90, Cs-137, and Sb-125 and by at least two orders of magnitude the portioning of Tc-99 to the first and subsequent cycle waste streams that went to cribs. Conversely, the current scheme underestimates the lanthanide and yttrium fission product quantities that went to cribs by a factor of about 3.

  10. Evidence of microscopic effects in fragment mass distribution in heavy ion induced fusion-fission reactions

    E-Print Network [OSTI]

    T. K. Ghosh; S. Pal; K. S. Gold; P. Bhattacharya

    2005-06-27T23:59:59.000Z

    Our measurements of variances ($\\sigma_{m}^2$) in mass distributions of fission fragments from fusion-fission reactions of light projectiles (C, O and F) on deformed thorium targets exhibit a sharp anomalous increase with energy near the Coulomb barrier, in contrast to the smooth variation of $\\sigma_{m}^2$ for the spherical bismuth target. This departure from expectation based on a statistical description is explained in terms of microscopic effects arising from the orientational dependence in the case of deformed thorium targets.

  11. Fission track evidence for widespread early to Middle miocene extension in

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdf Jump to:ar-80m.pdfFillmore County,and Wildlife Service JumpFishermenthe

  12. Determination of the transuranic dose equivalent to the Rongelapese from urinary output analyzed by the fission track method

    E-Print Network [OSTI]

    Taylor, George Anthony

    1989-01-01T23:59:59.000Z

    materials and fission products, 2s9Pu is the major radionuclide of concern in the contamination of the environment (Sun 1984). Internally deposited plutonium is extremely hazardous to man, mainly because of its long effective half-life. It has been... Background Transuranic Dose MATERIAL AND METHODS Plutonium In Man . Urinalysis . Whole Body Counting (WBC) . Computer Programs Data Analysis . . . . . RESULTS AND DISCUSSION . CONCLUSIONS RECOMMENDATIONS ON FURTHER WORK REFERENCES VITA . Page Vl...

  13. Peer Effects and the Impact of Tracking: Evidence from a Randomized Evaluation in Kenya

    E-Print Network [OSTI]

    Duflo, Esther; Dupas, Pascaline; Kremer, Michael

    2008-01-01T23:59:59.000Z

    Score Initial Attainment Percentile Tracking Schools Non-Score Initial Attainment Percentile Tracking Schools Non-assignment at the 50 th percentile for most Note that the

  14. Peer Effects, Teacher Incentives, and the Impact of Tracking: Evidence from a Randomized Evaluation in Kenya

    E-Print Network [OSTI]

    Duflo, Esther

    To the extent that students benefit from high-achieving peers, tracking will help strong students and hurt weak ones. However, all students may benefit if tracking allows teachers to better tailor their instruction level. ...

  15. Benchmarking Nuclear Fission Theory

    E-Print Network [OSTI]

    Bertsch, G F; Nazarewicz, W; Talou, P

    2015-01-01T23:59:59.000Z

    We suggest a small set of fission observables to be used as test cases for validation of theoretical calculations. The purpose is to provide common data to facilitate the comparison of different fission theories and models. The proposed observables are chosen from fission barriers, spontaneous fission lifetimes, fission yield characteristics, and fission isomer excitation energies.

  16. Benchmarking Nuclear Fission Theory

    E-Print Network [OSTI]

    G. F. Bertsch; W. Loveland; W. Nazarewicz; P. Talou

    2015-02-20T23:59:59.000Z

    We suggest a small set of fission observables to be used as test cases for validation of theoretical calculations. The purpose is to provide common data to facilitate the comparison of different fission theories and models. The proposed observables are chosen from fission barriers, spontaneous fission lifetimes, fission yield characteristics, and fission isomer excitation energies.

  17. Fission meter

    DOE Patents [OSTI]

    Rowland, Mark S. (Alamo, CA); Snyderman, Neal J. (Berkeley, CA)

    2012-04-10T23:59:59.000Z

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source.

  18. Fission theory: Its relevance to the nuclear cross section data base

    SciTech Connect (OSTI)

    Lynn, J.E.

    1989-01-01T23:59:59.000Z

    The development of fission reaction theory in relation to its predictive power in the calculation of neutron cross-sections is reviewed. The topics covered include the transition state spectrum and the channel theory; the discovery of complex topography in the fission barrier and the consequences of intermediate structure in fission cross-sections; the evidence of experimental data in parameterizing the fission barrier; and the role of other aspects of collective nuclear motion in controlling fission reaction rates. 51 refs., 6 figs.

  19. A Time Projection Chamber for High Accuracy and Precision Fission Cross-Section Measurements

    SciTech Connect (OSTI)

    T. Hill; K. Jewell; M. Heffner; D. Carter; M. Cunningham; V. Riot; J. Ruz; S. Sangiorgio; B. Seilhan; L. Snyder; D. M. Asner; S. Stave; G. Tatishvili; L. Wood; R. G. Baker; J. L. Klay; R. Kudo; S. Barrett; J. King; M. Leonard; W. Loveland; L. Yao; C. Brune; S. Grimes; N. Kornilov; T. N. Massey; J. Bundgaard; D. L. Duke; U. Greife; U. Hager; E. Burgett; J. Deaven; V. Kleinrath; C. McGrath; B. Wendt; N. Hertel; D. Isenhower; N. Pickle; H. Qu; S. Sharma; R. T. Thornton; D. Tovwell; R. S. Towell; S.

    2014-09-01T23:59:59.000Z

    The fission Time Projection Chamber (fissionTPC) is a compact (15 cm diameter) two-chamber MICROMEGAS TPC designed to make precision cross-section measurements of neutron-induced fission. The actinide targets are placed on the central cathode and irradiated with a neutron beam that passes axially through the TPC inducing fission in the target. The 4p acceptance for fission fragments and complete charged particle track reconstruction are powerful features of the fissionTPC which will be used to measure fission cross-sections and examine the associated systematic errors. This paper provides a detailed description of the design requirements, the design solutions, and the initial performance of the fissionTPC.

  20. Delayed-fission properties of neutron-deficient americium nuclei

    SciTech Connect (OSTI)

    Hall, H.L. (California Univ., Berkeley, CA (USA). Dept. of Chemistry)

    1989-10-23T23:59:59.000Z

    Characteristics of the delayed-fission decay mode in light americium nuclei have been investigated. Measurements on the unknown isotopes {sup 230}Am and {sup 236}Am were attempted, and upper limits on the delayed-fission branches of these nuclei were determined. Evidence of the existence of {sup 236}Am was observed in radiochemical separations. Total kinetic energy and mass-yield distributions of the electron-capture delayed-fission mode were measured for {sup 232}Am (t{sub 1/2} = 1.31 {plus minus} 0.04 min) and for {sup 234}Am (t{sub 1/2} = 2.32 {plus minus} 0.08 min), and delayed-fission probabilities of 6.9 {times} 10{sup {minus}4} and 6.6 {times} 10{sup {minus}5}, respectively, were determined. The total kinetic energy and the asymmetric mass-yield distributions are typical of fission of mid-range actinides. No discernible influence of the anomalous triple-peaked mass division characteristic of the thorium-radium region was detected. Measurements of the time correlation between the electron-capture x-rays and the subsequent fission conform that the observed fissions arise from the electron-capture delayed-fission mechanism. Delayed fission has provided a unique opportunity to extend the range of low-energy fission studies to previously inaccessible regions. 71 refs., 44 figs., 13 tabs.

  1. Fission gas detection system

    DOE Patents [OSTI]

    Colburn, Richard P. (Pasco, WA)

    1985-01-01T23:59:59.000Z

    A device for collecting fission gas released by a failed fuel rod which device uses a filter to pass coolant but which filter blocks fission gas bubbles which cannot pass through the filter due to the surface tension of the bubble.

  2. 3He- and 4He-induced nuclear fission - a test of the transition state method

    E-Print Network [OSTI]

    Th. Rubehn; K. X. Jing; L. G. Moretto; L. Phair; K. Tso; G. J. Wozniak

    1997-04-18T23:59:59.000Z

    Fission in 3He and 4He induced reactions at excitation energies between the fission barrier and 140 MeV has been investigated. Twentythree fission excitation functions of various compound nuclei in different mass regions are shown to scale exactly according to the transition state prediction once the shell effects are accounted for. New precise measurements of excitation functions in a mass region where shell effects are very strong, allow one to test the predictions with an even higher accuracy. The fact that no deviations from the transition state method have been observed within the experimentally investigated excitation energy regime allows one to assign limits for the fission transient time. The precise measurement of fission excitation functions of neighboring isotopes enables us to experimentally estimate the first chance fission probability. Even if only first chance fission is investigated, no evidence for fission transient times larger than 30 zs can be found.

  3. Singlet fission photovoltaics

    E-Print Network [OSTI]

    Lee, Jiye

    2013-01-01T23:59:59.000Z

    The efficiency of a solar cell is restricted by the "single junction limit," whereby photons with energy higher than the bandgap lose energy by thermalization. Singlet exciton fission splits a high-energy molecular excitation ...

  4. Multi-pronged events from Coulomb fission of nuclei at very low energies

    E-Print Network [OSTI]

    B. Basu; S. Dey; D. Gupta; A. Maulik; S. Raha; Swapan K. Saha; D. Syam

    2008-11-29T23:59:59.000Z

    Multi-pronged tracks have been recorded in the polyethylene terephthalate (C$_{10}$H$_8$O$_4$)$_n$ solid state nuclear track detector by exposure to a $^{252}$Cf fission source. After chemical etching, two-prong to six-pronged tracks along with single tracks have been observed under the optical microscope. We carried out a systematic study to understand the origin of the prongs. The track detectors were coated with metals (Cu, Ag and Pb) and were exposed to $^{252}$Cf source. After chemical etching two-prong to four pronged tracks were observed in each plate. We believe that at this very low energy of the order of 1 MeV/A, Coulomb fission is the only plausible explanation for the origin of such multi-pronged tracks.

  5. Threshold for dissipative fission

    SciTech Connect (OSTI)

    Thoennessen, M.; Bertsch, G.F. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States) Department of Physics, FM-15, University of Washington, Seattle, Washington 98105 (United States))

    1993-12-27T23:59:59.000Z

    We examine the empirical domain of validity of statistical theory, as applied to fission data on prefission neutron, charged particle, and [gamma]-ray multiplicities. Systematics are found in the threshold excitation energy for the appearance of nonstatistical fission. From the data on systems with not too high fissility,, the relevant phenomenological parameter is the ratio of the threshold temperature [ital T][sub thresh] to the (temperature dependent) fission barrier height [ital E][sub bar([ital T])]. The statistical model reproduces the data for [ital T][sub thresh]/[ital E][sub bar([ital T])[lt]0.26][plus minus]0.05 but underpredicts the multiplicities at higher [ital T][sub thresh]/[ital E][sub bar([ital T])] independent of mass and fissility of the systems.

  6. Call Title: Nuclear Fission and Radiation Protection Call Identifier: FP7-Fission-2009

    E-Print Network [OSTI]

    De Cindio, Fiorella

    Fission-2.2 Fission-2009-2.2.1: Conceptual design of lead and gas cooled fast reactor systems Max. of 2 and transmutation Fission-1.2 (refer to Fission-2.3) Reactor Systems: Fission-2 Fission-2.1 Fission-2009-2.1.1: Structural integrity assessment for safety and lifetime management of the Reactor Coolant System piping

  7. 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

    2014-11-01T23:59:59.000Z

    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 5.2×1021 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.

  8. Post-scission fission theory: Neutron emission in fission

    SciTech Connect (OSTI)

    Madland, D.G.

    1997-11-01T23:59:59.000Z

    A survey of theoretical representations of two of the observables in neutron emission in fission is given, namely, the prompt fission neutron spectrum N (E) and the average prompt neutron multiplicity {bar {nu}}{sub p}. Early representations of the two observables are presented and their deficiencies are discussed. This is followed by summaries and examples of recent theoretical models for the calculation of these quantities. Emphasis is placed upon the predictability and accuracy of the recent models. In particular, the dependencies of N (E) and {bar {nu}}{sub p} upon the fissioning nucleus and its excitation energy are treated. Recent work in the calculation of the prompt fission neutron spectrum matrix N (E, E{sub n}), where E{sub n} is the energy of the neutron inducing fission, is then discussed. Concluding remarks address the current status of our ability to calculate these observables with confidence, the direction of future theoretical efforts, and limitations to current (and future) approaches.

  9. FISSION OF GOLD BY CARBON IONS

    E-Print Network [OSTI]

    Gordon, Glen E.; Larsh, Almon E.; Sikkeland, Torbjorn; Seaborg, Glenn T.

    2008-01-01T23:59:59.000Z

    and J. R. Huizenga, Nuclear Fission (to be published inHeavy-lon-Induced Nuclear Fission, (to be published in Proc.

  10. Fission throughout the periodic table

    SciTech Connect (OSTI)

    Moretto, L.G.; Wozniak, G.J.

    1989-04-01T23:59:59.000Z

    The dualistic view of fission and evaporation as two distinct compound nucleus processes is substituted with a unified view in which fission, complex fragment emission, and light particle evaporation are seen as different aspects of a single process. 47 refs., 22 figs.

  11. TRACKING SITE

    Energy Science and Technology Software Center (OSTI)

    003235MLTPL00 AASG Geothermal Data submissions tracking application and site.  https://github.com/usgin/aasgtrack 

  12. Infrared Spectroscopy of Wild 2 Particle Hypervelocity Tracks in Stardust Aerogel: Evidence for the presence of Volatile Organics in Comet Dust

    SciTech Connect (OSTI)

    Bajt, S; Sandford, S A; Flynn, G J; Matrajt, G; Snead, C J; Westphal, A J; Bradley, J P

    2007-08-28T23:59:59.000Z

    Infrared spectroscopy maps of some tracks, made by cometary dust from 81P/Wild 2 impacting Stardust aerogel, reveal an interesting distribution of volatile organic material. Out of six examined tracks three show presence of volatile organic components possibly injected into the aerogel during particle impacts. When particle tracks contained excess volatile organic material, they were found to be -CH{sub 2}-rich. Off-normal particle tracks could indicate impacts by lower velocity particles that could have bounced off the Whipple shield, therefore carry off some contamination from it. However, this theory is not supported by data that show excess organic-rich material in normal and off-normal particle tracks. It is clear that the population of cometary particles impacting the Stardust aerogel collectors also include grains that contained little or none of this volatile organic component. This observation is consistent with the highly heterogeneous nature of the collected grains, as seen by a multitude of other analytical techniques. We propose that at least some of the volatile organic material might be of cometary origin based on supporting data shown in this paper. However, we also acknowledge the presence of carbon (primarily as -CH{sub 3}) in the original aerogel, which complicates interpretation of these results.

  13. Assessment of the high temperature fission chamber technology for the French fast reactor program

    SciTech Connect (OSTI)

    Jammes, C.; Filliatre, P.; Geslot, B.; Domenech, T.; Normand, S. [Commissariat a l'Energie Atomique, CEA (France)

    2011-07-01T23:59:59.000Z

    High temperature fission chambers are key instruments for the control and protection of the sodium-cooled fast reactor. First, the developments of those neutron detectors, which are carried out either in France or abroad are reviewed. Second, the French realizations are assessed with the use of the technology readiness levels in order to identify tracks of improvement. (authors)

  14. ADIABATICITY CRITERION FOR CHARGE EQUILIBRATION WITH APPLICATION TO FISSION

    E-Print Network [OSTI]

    Myers, W.D.

    2013-01-01T23:59:59.000Z

    strongly damped nuclear collisions and in fission. This work48, In nuclear collisions and in fission the fluctuations instages of fission and strongly damped nuclear collisions the

  15. Nuclear Fission: Reaction to the Discovery in 1939

    E-Print Network [OSTI]

    Hodes, Elizabeth; Tiddens, Adolph; Badash, Lawrence

    1985-01-01T23:59:59.000Z

    and A. v. Grosse, "Nuclear fission of separated uraniumThe mechanism of nuclear fission," Physical Review, 56 (1liberated in the nuclear fission of uranium," Nature, 143 (

  16. Improved zircon fission-track annealing model based on reevaluation...

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

    t 0, which is independent of the current state of lattice deformation. This implies that iso-annealing curves should converge to a fanning point in the Arrhenius pseudo-space (ln t...

  17. Fission product solvent extraction

    SciTech Connect (OSTI)

    Moyer, B.A.; Bonnesen, P.V.; Sachleben, R.A. [and others

    1998-02-01T23:59:59.000Z

    Two main objectives concerning removal of fission products from high-level tank wastes will be accomplished in this project. The first objective entails the development of an acid-side Cs solvent-extraction (SX) process applicable to remediation of the sodium-bearing waste (SBW) and dissolved calcine waste (DCW) at INEEL. The second objective is to develop alkaline-side SX processes for the combined removal of Tc, Cs, and possibly Sr and for individual separation of Tc (alone or together with Sr) and Cs. These alkaline-side processes apply to tank wastes stored at Hanford, Savannah River, and Oak Ridge. This work exploits the useful properties of crown ethers and calixarenes and has shown that such compounds may be economically adapted to practical processing conditions. Potential benefits for both acid- and alkaline-side processing include order-of-magnitude concentration factors, high rejection of bulk sodium and potassium salts, and stripping with dilute (typically 10 mM) nitric acid. These benefits minimize the subsequent burden on the very expensive vitrification and storage of the high-activity waste. In the case of the SRTALK process for Tc extraction as pertechnetate anion from alkaline waste, such benefits have now been proven at the scale of a 12-stage flowsheet tested in 2-cm centrifugal contactors with a Hanford supernatant waste simulant. SRTALK employs a crown ether in a TBP-modified aliphatic kerosene diluent, is economically competitive with other applicable separation processes being considered, and has been successfully tested in batch extraction of actual Hanford double-shell slurry feed (DSSF).

  18. The Metabolic Properties of the Fission Products and Actinide Elements

    E-Print Network [OSTI]

    Hamilton M.D., J.G.

    2010-01-01T23:59:59.000Z

    directly from nuclear fission. Radioactive substances can··free Fission Prodl,wts in the Rat" Natl Nuclear Energy

  19. THE WIDTH OF THE CHARGE DISTRIBUTION IN FISSION

    E-Print Network [OSTI]

    Myers, W.D.

    2010-01-01T23:59:59.000Z

    strongly damped nuclear collisions or in fission. Since theDistribution in Fission William 0. Myers Nuclear Science

  20. Quantum efficiency and fission rate in tetracene

    E-Print Network [OSTI]

    Wu, Tony Chang-Chi

    2013-01-01T23:59:59.000Z

    Using singlet fission in a photovoltaic cell, the theoretical energy conversion efficiency limit is larger than the Shockley-Queisser limit due to two excitons produced with one incident photon. In a singlet fission material, ...

  1. The nucleon phase hypothesis of binary fission

    E-Print Network [OSTI]

    G. Mouze; S. Hachem; C. Ythier

    2010-06-29T23:59:59.000Z

    The mass distribution of fission fragments of actinide and superheavy nuclei can be explained if a new state of nuclear matter, a nucleon phase, is created in any fission event.

  2. Nuclear fission in covariant density functional theory

    E-Print Network [OSTI]

    A. V. Afanasjev; H. Abusara; P. Ring

    2013-09-12T23:59:59.000Z

    The current status of the application of covariant density functional theory to microscopic description of nuclear fission with main emphasis on superheavy nuclei (SHN) is reviewed. The softness of SHN in the triaxial plane leads to an emergence of several competing fission pathes in the region of the inner fission barrier in some of these nuclei. The outer fission barriers of SHN are considerably affected both by triaxiality and octupole deformation.

  3. Process for treating fission waste. [Patent application

    DOE Patents [OSTI]

    Rohrmann, C.A.; Wick, O.J.

    1981-11-17T23:59:59.000Z

    A method is described for the treatment of fission waste. A glass forming agent, a metal oxide, and a reducing agent are mixed with the fission waste and the mixture is heated. After melting, the mixture separates into a glass phase and a metal phase. The glass phase may be used to safely store the fission waste, while the metal phase contains noble metals recovered from the fission waste.

  4. Neutronics for critical fission reactors and subcritical fission in hybrids

    SciTech Connect (OSTI)

    Salvatores, Massimo [CEA-Cadarache, DEN-Dir, Bat. 101, St-Paul-Lez-Durance 13108 (France)

    2012-06-19T23:59:59.000Z

    The requirements of future innovative nuclear fuel cycles will focus on safety, sustainability and radioactive waste minimization. Critical fast neutron reactors and sub-critical, external source driven systems (accelerator driven and fusion-fission hybrids) have a potential role to meet these requirements in view of their physics characteristics. This paper provides a short introduction to these features.

  5. Fission matrix capability for MCNP, Part I - Theory

    SciTech Connect (OSTI)

    Brown, F. B. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States); Carney, S. E. [University of Michigan, NERS Department, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Kiedrowski, B. C. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States); Martin, W. R. [University of Michigan, NERS Department, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States)

    2013-07-01T23:59:59.000Z

    The theory underlying the fission matrix method is derived using a rigorous Green's function approach. The method is then used to investigate fundamental properties of the transport equation for a continuous-energy physics treatment. We provide evidence that an infinite set of discrete, real eigenvalues and eigenfunctions exist for the continuous-energy problem, and that the eigenvalue spectrum converges smoothly as the spatial mesh for the fission matrix is refined. We also derive equations for the adjoint solution. We show that if the mesh is sufficiently refined so that both forward and adjoint solutions are valid, then the adjoint fission matrix is identical to the transpose of the forward matrix. While the energy-dependent transport equation is strictly bi-orthogonal, we provide surprising results that the forward modes are very nearly self-adjoint for a variety of continuous-energy problems. A companion paper (Part II - Applications) describes the initial experience and results from implementing this fission matrix capability into the MCNP Monte Carlo code. (authors)

  6. Space Fission System Test Effectiveness

    SciTech Connect (OSTI)

    Houts, Mike [Los Alamos National Laboratory, MS-K575, Los Alamos, NM 87545 (United States); Schmidt, Glen L. [New Mexico Tech, Institute for Engineering Research and Applications, 901 University Blvd SE, Albuquerque, NM 87109-4339 (United States); Van Dyke, Melissa; Godfroy, Tom; Martin, James; Bragg-Sitton, Shannon; Dickens, Ricky; Salvail, Pat; Harper, Roger [NASA MSFC, TD40, Marshall Space Flight Center, AL, 35812 (United States)

    2004-02-04T23:59:59.000Z

    Space fission technology has the potential to enable rapid access to any point in the solar system. If fission propulsion systems are to be developed to their full potential, however, near-term customers need to be identified and initial fission systems successfully developed, launched, and utilized. One key to successful utilization is to develop reactor designs that are highly testable. Testable reactor designs have a much higher probability of being successfully converted from paper concepts to working space hardware than do designs which are difficult or impossible to realistically test. ''Test Effectiveness'' is one measure of the ability to realistically test a space reactor system. The objective of this paper is to discuss test effectiveness as applied to the design, development, flight qualification, and acceptance testing of space fission systems. The ability to perform highly effective testing would be particularly important to the success of any near-term mission, such as NASA's Jupiter Icy Moons Orbiter, the first mission under study within NASA's Project Prometheus, the Nuclear Systems Program.

  7. High resolution track etch autoradiography

    DOE Patents [OSTI]

    Solares, G.; Zamenhof, R.G.

    1994-12-27T23:59:59.000Z

    A detector assembly is disclosed for use in obtaining alpha-track autoradiographs, the detector assembly including a substantially boron-free substrate; a detector layer deposited on the substantially boron-free substrate, the detector layer being capable of recording alpha particle tracks and exhibiting evidence of the alpha tracks in response to being exposed to an etchant, the detector layer being less than about 2 microns thick; and a protective layer deposited on the detector layer, the protective layer being resistant to the etchant and having a thickness of about 0.5 to 1 microns. 13 figures.

  8. Microscopic Description of Nuclear Fission Dynamics

    E-Print Network [OSTI]

    A. S. Umar; V. E. Oberacker; J. A. Maruhn; P. -G. Reinhard

    2010-03-22T23:59:59.000Z

    We discuss possible avenues to study fission dynamics starting from a time-dependent mean-field approach. Previous attempts to study fission dynamics using the time-dependent Hartree-Fock (TDHF) theory are analyzed. We argue that different initial conditions may be needed to describe fission dynamics depending on the specifics of the fission phenomenon and propose various approaches towards this goal. In particular, we provide preliminary calculations for studying fission following a heavy-ion reaction using TDHF with a density contraint. Regarding prompt muon-induced fission, we also suggest a new approach for combining the time-evolution of the muonic wave function with a microscopic treatment of fission dynamics via TDHF.

  9. Fusion-Fission Hybrid for Fissile Fuel Production without Processing

    SciTech Connect (OSTI)

    Fratoni, M; Moir, R W; Kramer, K J; Latkowski, J F; Meier, W R; Powers, J J

    2012-01-02T23:59:59.000Z

    Two scenarios are typically envisioned for thorium fuel cycles: 'open' cycles based on irradiation of {sup 232}Th and fission of {sup 233}U in situ without reprocessing or 'closed' cycles based on irradiation of {sup 232}Th followed by reprocessing, and recycling of {sup 233}U either in situ or in critical fission reactors. This study evaluates a third option based on the possibility of breeding fissile material in a fusion-fission hybrid reactor and burning the same fuel in a critical reactor without any reprocessing or reconditioning. This fuel cycle requires the hybrid and the critical reactor to use the same fuel form. TRISO particles embedded in carbon pebbles were selected as the preferred form of fuel and an inertial laser fusion system featuring a subcritical blanket was combined with critical pebble bed reactors, either gas-cooled or liquid-salt-cooled. The hybrid reactor was modeled based on the earlier, hybrid version of the LLNL Laser Inertial Fusion Energy (LIFE1) system, whereas the critical reactors were modeled according to the Pebble Bed Modular Reactor (PBMR) and the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) design. An extensive neutronic analysis was carried out for both the hybrid and the fission reactors in order to track the fuel composition at each stage of the fuel cycle and ultimately determine the plant support ratio, which has been defined as the ratio between the thermal power generated in fission reactors and the fusion power required to breed the fissile fuel burnt in these fission reactors. It was found that the maximum attainable plant support ratio for a thorium fuel cycle that employs neither enrichment nor reprocessing is about 2. This requires tuning the neutron energy towards high energy for breeding and towards thermal energy for burning. A high fuel loading in the pebbles allows a faster spectrum in the hybrid blanket; mixing dummy carbon pebbles with fuel pebbles enables a softer spectrum in the critical reactors. This combination consumes about 20% of the thorium initially loaded in the hybrid reactor ({approx}200 GWd/tHM), partially during hybrid operation, but mostly during operation in the critical reactor. The plant support ratio is low compared to the one attainable using continuous fuel chemical reprocessing, which can yield a plant support ratio of about 20, but the resulting fuel cycle offers better proliferation resistance as fissile material is never separated from the other fuel components.

  10. Nuclear-fission studies with relativistic secondary beams: analysis of fission channels

    E-Print Network [OSTI]

    C. Boeckstiegel; S. Steinhaeuser; K. -H. Schmidt; H. -G. Clerc; A. Grewe; A. Heinz; M. de Jong; A. R. Junghans; J. Mueller; B. Voss

    2007-12-21T23:59:59.000Z

    Nuclear fission of several neutron-deficient actinides and pre-actinides from excitation energies around 11 MeV was studied at GSI Darmstadt by use of relativistic secondary beams. The characteristics of multimodal fission of nuclei around 226Th are systematically investigated and interpreted as the superposition of three fission channels. Properties of these fission channels have been determined for 15 systems. A global view on the properties of fission channels including previous results is presented. The positions of the asymmetric fission channels are found to be constant in element number over the whole range of systems investigated.

  11. Fission dynamics within time-dependent Hartree-Fock: deformation-induced fission

    E-Print Network [OSTI]

    Goddard, P M; Rios, A

    2015-01-01T23:59:59.000Z

    Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations ignoring dynamical excitations of the fissioning nucleus, and the daughter products. Purpose: To explore the ability of dynamic mean-field methods to describe fast fission processes beyond the fission barrier, using the nuclide $^{240}$Pu as an example. Methods: Time-dependent Hartree-Fock calculations based on the Skyrme interaction are used to calculate non-adiabatic fission paths, beginning from static constrained Hartree-Fock calculations. The properties of the dynamic states are interpreted in terms of the nature of their collective motion. Fission product properties are compared to data. Results: Parent nuclei constrained to begin dynamic evolution with a deformation less than the fission barrier exhibit giant-resonance-type behaviour. Those beginning just beyond the ...

  12. Fission barriers and half-lives

    SciTech Connect (OSTI)

    Moeller, P.; Nix, J.R.; Swiatecki, W.J.

    1989-01-01T23:59:59.000Z

    We briefly review the development of theoretical models for the calculation of fission barriers and half-lives. We focus on how results of actual calculations in a unified macroscopic-microscopic approach provide an interpretation of the mechanisms behind some of the large number of phenomena observed in fission. As instructive examples we choose studies of the rapidly varying fission properties of elements at the end of the periodic system. 31 refs., 10 figs.

  13. Cycle Track Lessons Learned

    E-Print Network [OSTI]

    Bertini, Robert L.

    Cycle Track Lessons Learned #12;Presentation Overview · Bicycling trends · Cycle track lessons learned · What is a "Cycle track"? · Essential design elements of cycle tracks Separation Width Crossing

  14. Some Considerations on the Probability of Nuclear Fission

    E-Print Network [OSTI]

    Vandenbosch, Robert; Seaborg, Glenn T.

    1957-01-01T23:59:59.000Z

    om THE PROBABILITY OF NUCLEAR FISSION Robert Vandenbosch andON TRE PROBABILITY OF NUCLEAR FISSION O E Contents Abstractf is the fission threshold, and the nuclear temperature T is

  15. Fission fragment excited laser system

    DOE Patents [OSTI]

    McArthur, David A. (Albuquerque, NM); Tollefsrud, Philip B. (Albuquerque, NM)

    1976-01-01T23:59:59.000Z

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  16. SciTech Connect: The Microscopic Theory of Fission

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: Presented at: 4th international workshop on nuclear fission and fission-product spectroscopy, cadarache, France, May 13 - May 16, 2009...

  17. Improvement of the Fission Channel in the EMPIRE Code

    SciTech Connect (OSTI)

    Sin, M. [University of Bucharest, Bucharest (Romania); Capote, R.; Trkov, A. [International Atomic Energy Agency, Vienna (Austria); Herman, M.; Oblozinsky, P. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Ventura, A. [Ente Nazionale Energie Alternative, Bologna (Italy)

    2005-05-24T23:59:59.000Z

    The new fission formalism implemented in EMPIRE-2.19 is presented along with several examples of applications to neutron- and photon-induced fission.

  18. Fission dynamics within time-dependent Hartree-Fock: deformation-induced fission

    E-Print Network [OSTI]

    P. M. Goddard; P. D. Stevenson; A. Rios

    2015-04-03T23:59:59.000Z

    Background: Nuclear fission is a complex large-amplitude collective decay mode in heavy nuclei. Microscopic density functional studies of fission have previously concentrated on adiabatic approaches based on constrained static calculations ignoring dynamical excitations of the fissioning nucleus, and the daughter products. Purpose: To explore the ability of dynamic mean-field methods to describe fast fission processes beyond the fission barrier, using the nuclide $^{240}$Pu as an example. Methods: Time-dependent Hartree-Fock calculations based on the Skyrme interaction are used to calculate non-adiabatic fission paths, beginning from static constrained Hartree-Fock calculations. The properties of the dynamic states are interpreted in terms of the nature of their collective motion. Fission product properties are compared to data. Results: Parent nuclei constrained to begin dynamic evolution with a deformation less than the fission barrier exhibit giant-resonance-type behaviour. Those beginning just beyond the barrier explore large amplitude motion but do not fission, whereas those beginning beyond the two-fragment pathway crossing fission to final states which differ according to the exact initial deformation. Conclusions: Time-dependent Hartree-Fock is able to give a good qualitative and quantitative description of fast fission, provided one begins from a sufficiently deformed state.

  19. Options for Affordable Fission Surface Power Systems

    SciTech Connect (OSTI)

    Houts, Mike; Gaddis, Steve; Porter, Ron; Van Dyke, Melissa; Martin, Jim; Godfroy, Tom; Bragg-Sitton, Shannon; Garber, Anne; Pearson, Boise [NASA Marshall Space Flight Center, VP31, MSFC, AL 35812 (United States)

    2006-07-01T23:59:59.000Z

    Fission surface power systems could provide abundant power anywhere on the surface of the moon or Mars. Locations could include permanently shaded regions on the moon and high latitudes on Mars. To be fully utilized, however, fission surface power systems must be safe, have adequate performance, and be affordable. This paper discusses options for the design and development of such systems. (authors)

  20. Theoretical Description of the Fission Process

    SciTech Connect (OSTI)

    Witold Nazarewicz

    2009-10-25T23:59:59.000Z

    Advanced theoretical methods and high-performance computers may finally unlock the secrets of nuclear fission, a fundamental nuclear decay that is of great relevance to society. In this work, we studied the phenomenon of spontaneous fission using the symmetry-unrestricted nuclear density functional theory (DFT). Our results show that many observed properties of fissioning nuclei can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. From the calculated collective potential and collective mass, we estimated spontaneous fission half-lives, and good agreement with experimental data was found. We also predicted a new phenomenon of trimodal spontaneous fission for some transfermium isotopes. Our calculations demonstrate that fission barriers of excited superheavy nuclei vary rapidly with particle number, pointing to the importance of shell effects even at large excitation energies. The results are consistent with recent experiments where superheavy elements were created by bombarding an actinide target with 48-calcium; yet even at high excitation energies, sizable fission barriers remained. Not only does this reveal clues about the conditions for creating new elements, it also provides a wider context for understanding other types of fission. Understanding of the fission process is crucial for many areas of science and technology. Fission governs existence of many transuranium elements, including the predicted long-lived superheavy species. In nuclear astrophysics, fission influences the formation of heavy elements on the final stages of the r-process in a very high neutron density environment. Fission applications are numerous. Improved understanding of the fission process will enable scientists to enhance the safety and reliability of the nation’s nuclear stockpile and nuclear reactors. The deployment of a fleet of safe and efficient advanced reactors, which will also minimize radiotoxic waste and be proliferation-resistant, is a goal for the advanced nuclear fuel cycles program. While in the past the design, construction, and operation of reactors were supported through empirical trials, this new phase in nuclear energy production is expected to heavily rely on advanced modeling and simulation capabilities.

  1. Superfluid dynamics of 258Fm fission

    E-Print Network [OSTI]

    Scamps, Guillaume; Lacroix, Denis

    2015-01-01T23:59:59.000Z

    Theoretical description of nuclear fission remains one of the major challenges of quantum many-body dynamics. The slow, mostly adiabatic motion through the fission barrier is followed by a fast, non-adiabatic descent of the potential between the fragments. The latter stage is essentially unexplored. However, it is crucial as it generates most of the excitation energy in the fragments. The superfluid dynamics in the latter stage of fission is obtained with the time-dependent Hartree-Fock theory including BCS dynamical pairing correlations. The fission modes of the 258Fm nucleus are studied. The resulting fission fragment characteristics show a good agreement with experimental data. Quantum shell effects are shown to play a crucial role in the dynamics and formation of the fragments. The importance of quantum fluctuations beyond the independent particle/quasi-particle picture is underlined and qualitatively studied.

  2. Superfluid dynamics of 258Fm fission

    E-Print Network [OSTI]

    Guillaume Scamps; Cédric Simenel; Denis Lacroix

    2015-01-15T23:59:59.000Z

    Theoretical description of nuclear fission remains one of the major challenges of quantum many-body dynamics. The slow, mostly adiabatic motion through the fission barrier is followed by a fast, non-adiabatic descent of the potential between the fragments. The latter stage is essentially unexplored. However, it is crucial as it generates most of the excitation energy in the fragments. The superfluid dynamics in the latter stage of fission is obtained with the time-dependent Hartree-Fock theory including BCS dynamical pairing correlations. The fission modes of the 258Fm nucleus are studied. The resulting fission fragment characteristics show a good agreement with experimental data. Quantum shell effects are shown to play a crucial role in the dynamics and formation of the fragments. The importance of quantum fluctuations beyond the independent particle/quasi-particle picture is underlined and qualitatively studied.

  3. Event-by-Event Fission with FREYA

    SciTech Connect (OSTI)

    Randrup, J; Vogt, R

    2010-11-09T23:59:59.000Z

    The recently developed code FREYA (Fission Reaction Event Yield Algorithm) generates large samples of complete fission events, consisting of two receding product nuclei as well as a number of neutrons and photons, all with complete kinematic information. Thus it is possible to calculate arbitrary correlation observables whose behavior may provide unique insight into the fission process. The presentation first discusses the present status of FREYA, which has now been extended up to energies where pre-equilibrium emission becomes significant and one or more neutrons may be emitted prior to fission. Concentrating on {sup 239}Pu(n,f), we discuss the neutron multiplicity correlations, the dependence of the neutron energy spectrum on the neutron multiplicity, and the relationship between the fragment kinetic energy and the number of neutrons and their energies. We also briefly suggest novel fission observables that could be measured with modern detectors.

  4. Improved Calculation of Thermal Fission Energy

    E-Print Network [OSTI]

    Ma, X B; Wang, L Z; Chen, Y X; Cao, J

    2013-01-01T23:59:59.000Z

    Thermal fission energy is one of the basic parameters needed in the calculation of antineutrino flux for reactor neutrino experiments. It is useful to improve the precision of the thermal fission energy calculation for current and future reactor neutrino experiments, which are aimed at more precise determination of neutrino oscillation parameters. In this article, we give new values for thermal fission energies of some common thermal reactor fuel iso-topes, with improvements on two aspects. One is more recent input data acquired from updated nuclear databases. The other, which is unprecedented, is a consideration of the production yields of fission fragments from both thermal and fast incident neutrons for each of the four main fuel isotopes. The change in calculated antineutrino flux due to the new values of thermal fission energy is about 0.33%, and the uncertainties of the new values are about 30% smaller.

  5. Future challenges for nuclear data research in fission (u)

    SciTech Connect (OSTI)

    Chadwick, Mark B [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    I describe some high priority research areas in nuclear fission, where applications in nuclear reactor technologies and in modeling criticality in general are demanding higher accuracies in our databases. We focus on fission cross sections, fission neutron spectra, and fission product data.

  6. Fission induced by nucleons at intermediate energies

    E-Print Network [OSTI]

    Sergio Lo Meo; Davide Mancusi; Cristian Massimi; Gianni Vannini; Alberto Ventura

    2014-09-17T23:59:59.000Z

    Monte Carlo calculations of fission of actinides and pre-actinides induced by protons and neutrons in the energy range from 100 MeV to 1 GeV are carried out by means of a recent version of the Li\\`ege Intranuclear Cascade Model, INCL++, coupled with two different evaporation-fission codes, GEMINI++ and ABLA07. In order to reproduce experimental fission cross sections, model parameters are usually adjusted on available (p,f) cross sections and used to predict (n,f) cross sections for the same isotopes.

  7. Microscopic description of complex nuclear decay: multimodal fission

    E-Print Network [OSTI]

    A. Staszczak; A. Baran; J. Dobaczewski; W. Nazarewicz

    2009-06-23T23:59:59.000Z

    Our understanding of nuclear fission, a fundamental nuclear decay, is still incomplete due to the complexity of the process. In this paper, we describe a study of spontaneous fission using the symmetry-unrestricted nuclear density functional theory. Our results show that the observed bimodal fission can be explained in terms of pathways in multidimensional collective space corresponding to different geometries of fission products. We also predict a new phenomenon of trimodal spontaneous fission for some rutherfordium, seaborgium, and hassium isotopes.

  8. FP7 Euratom Work Programme Call title: Nuclear Fission and Radiation Protection

    E-Print Network [OSTI]

    De Cindio, Fiorella

    Fission-1.1 Fission-2008-1.1.1: Gas generation and transport in support of performance assessment Large) Fission-1.2 Fission-2008-1.2.1: Establishment of a Central Design team (CDT) for a fast- spectrum-scale or large-scale #12;Reactor Systems: Fission-2 Fission-2.1 Fission-2008-2.1.1: Sustainable integration

  9. Electromechanical solar tracking apparatus

    DOE Patents [OSTI]

    Stromberg, Robert P. (Albuquerque, NM)

    1981-01-01T23:59:59.000Z

    The invention relates to an electromechanical solar tracking device which tracks the position of the sun using paired, partially-shaded bimetallic elements.

  10. Nuclear fission as resonance-mediated conductance

    E-Print Network [OSTI]

    G. F. Bertsch

    2014-12-18T23:59:59.000Z

    For 75 years the theory of nuclear fission has been based on the existence of a collective coordinate associated with the nuclear shape, an assumption required by the Bohr-Wheeler formula as well as by the R-matrix theory of fission. We show that it is also possible to formulate the theory without the help of collective coordinates. In the new formulation, fission is facilitated by individual states in the barrier region rather than channels over the barrier. In a certain limit the theory reduces to a formula closely related to the formula for electronic conductance through resonant tunneling states. In contrast, conduction through channels gives rise to a staircase excitation function that is well-known in nanoscale electronics but has never been seen in nuclear fission.

  11. Reactor power history from fission product signatures 

    E-Print Network [OSTI]

    Sweeney, David J.

    2009-05-15T23:59:59.000Z

    The purpose of this research was to identify fission product signatures that could be used to uniquely identify a specific spent fuel assembly in order to improve international safeguards. This capability would help prevent and deter potential...

  12. Fission reactor experiments for solid breeder blankets

    SciTech Connect (OSTI)

    Gierszewski, P.J.; Abdou, M.A.; Puigh, R.

    1986-11-01T23:59:59.000Z

    The testing needs for solid breeder blanket development are different from those for liquid breeder blankets. In particular, a reasonable number of moderate volume test sites in a neutron environment are needed. Existing fission reactors are shown to be able to provide this environment with reasonable simulation of many important blanket conditions. Three major additional fission reactor tests are identified beyond those presently underway. These are thermal behavior, advanced in-situ tritium recovery and nuclear submodule experiments.

  13. Modeling Fission Product Sorption in Graphite Structures

    SciTech Connect (OSTI)

    Szlufarska, Izabela [University of Wisconsin, Madison, WI (United States); Morgan, Dane [University of Wisconsin, Madison, WI (United States); Allen, Todd [University of Wisconsin, Madison, WI (United States)

    2013-04-08T23:59:59.000Z

    The goal of this project is to determine changes in adsorption and desorption of fission products to/from nuclear-grade graphite in response to a changing chemical environment. First, the project team will employ principle calculations and thermodynamic analysis to predict stability of fission products on graphite in the presence of structural defects commonly observed in very high- temperature reactor (VHTR) graphites. Desorption rates will be determined as a function of partial pressure of oxygen and iodine, relative humidity, and temperature. They will then carry out experimental characterization to determine the statistical distribution of structural features. This structural information will yield distributions of binding sites to be used as an input for a sorption model. Sorption isotherms calculated under this project will contribute to understanding of the physical bases of the source terms that are used in higher-level codes that model fission product transport and retention in graphite. The project will include the following tasks: Perform structural characterization of the VHTR graphite to determine crystallographic phases, defect structures and their distribution, volume fraction of coke, and amount of sp2 versus sp3 bonding. This information will be used as guidance for ab initio modeling and as input for sorptivity models; Perform ab initio calculations of binding energies to determine stability of fission products on the different sorption sites present in nuclear graphite microstructures. The project will use density functional theory (DFT) methods to calculate binding energies in vacuum and in oxidizing environments. The team will also calculate stability of iodine complexes with fission products on graphite sorption sites; Model graphite sorption isotherms to quantify concentration of fission products in graphite. The binding energies will be combined with a Langmuir isotherm statistical model to predict the sorbed concentration of fission products on each type of graphite site. The model will include multiple simultaneous adsorbing species, which will allow for competitive adsorption effects between different fission product species and O and OH (for modeling accident conditions).

  14. Our 50-year odyssey with fission: Summary

    SciTech Connect (OSTI)

    Nix, J.R.

    1989-01-01T23:59:59.000Z

    On the occasion of this International Conference on Fifty Years Research in Nuclear Fission, we summarize our present understanding of the fission process and the challenges that lie ahead. The basic properties of fission arise from a delicate competition between disruptive Coulomb forces, cohesive nuclear forces, and fluctuating shell and pairing forces. These static forces are primarily responsible for such experimental phenomena as deformed ground-state nuclear shapes, fission into fragments of unequal size, sawtooth neutron yields, spontaneously fissioning isomers, broad resonances and narrow intermediate structure in fission cross sections, and cluster radioactivity. However, inertial and dissipative forces also play decisive roles in the dynamical evolution of a fissioning nucleus. The energy dissipated between the saddle and scission points is small for low initial excitation energy at the saddle point and increases with increasing excitation energy. At moderate excitation energies, the dissipation of collective energy into internal single-particle excitation energy proceeds largely through the interaction of nucleons with the mean field and with each other in the vicinity of the nuclear surface, as well as through the transfer of nucleons between the two portions of the evolving dumbell-like system. These unique dissipation mechanisms arise from the Pauli exclusion principle for fermions and the details of the nucleon-nucleon interaction, which make the mean free path of a nucleon near the Fermi surface at low excitation energy longer than the nuclear radius. With its inverse process of heavy-ion fusion reactions, fission continues to yield surprises in the study of large-amplitude collective nuclear motion. 87 refs., 12 figs.

  15. Accurate fission data for nuclear safety

    E-Print Network [OSTI]

    A. Solders; D. Gorelov; A. Jokinen; V. S. Kolhinen; M. Lantz; A. Mattera; H. Penttila; S. Pomp; V. Rakopoulos; S. Rinta-Antila

    2013-04-08T23:59:59.000Z

    The Accurate fission data for nuclear safety (AlFONS) project aims at high precision measurements of fission yields, using the renewed IGISOL mass separator facility in combination with a new high current light ion cyclotron at the University of Jyvaskyla. The 30 MeV proton beam will be used to create fast and thermal neutron spectra for the study of neutron induced fission yields. Thanks to a series of mass separating elements, culminating with the JYFLTRAP Penning trap, it is possible to achieve a mass resolving power in the order of a few hundred thousands. In this paper we present the experimental setup and the design of a neutron converter target for IGISOL. The goal is to have a flexible design. For studies of exotic nuclei far from stability a high neutron flux (10^12 neutrons/s) at energies 1 - 30 MeV is desired while for reactor applications neutron spectra that resembles those of thermal and fast nuclear reactors are preferred. It is also desirable to be able to produce (semi-)monoenergetic neutrons for benchmarking and to study the energy dependence of fission yields. The scientific program is extensive and is planed to start in 2013 with a measurement of isomeric yield ratios of proton induced fission in uranium. This will be followed by studies of independent yields of thermal and fast neutron induced fission of various actinides.

  16. Theoretical descriptions of neutron emission in fission

    SciTech Connect (OSTI)

    Madland, D.G.

    1990-01-01T23:59:59.000Z

    Brief descriptions are given of the observables in neutron emission in fission together with early theoretical representations of two of these observables, namely, the prompt fission neutron spectrum N(E) and the average prompt neutron multiplicity {bar {nu}}{sub p}. This is followed by summaries, together with examples, of modern approaches to the calculation of these two quantities. Here, emphasis is placed upon the predictability and accuracy of the new approaches. In particular, the dependencies of N(E) and {bar {nu}}{sub p} upon the fissioning nucleus and its excitation energy are discussed. Then, recent work in multiple-chance fission and other recent work involving new measurements are presented and discussed. Following this, some properties of fission fragments are mentioned that must be better known and better understood in order to calculate N(E) and {bar {nu}}{sub p} with higher accuracy than is currently possible. In conclusion, some measurements are recommended for the purpose of benchmarking simultaneous calculations of neutron emission and gamma emission in fission. 32 refs., 26 figs.

  17. Uncertainty evaluation for the matrix 'solidified state' of fissionable elements

    SciTech Connect (OSTI)

    Iliescu, Elena; Iancso, Georgeta [National Institute of R and D for Physics and Nuclear Engineering-'Horia Hulubei', Str.Reactorului 30, P.O. BOX MG-6, Magurele (Romania)

    2012-09-06T23:59:59.000Z

    In case of the analysis of the radioactive liquid samples, no matter the relative physical analysis method used, two impediments act that belong to the behavior in time of the dispersion state of the liquid samples to be analyzed and of the standard used in the analysis. That is, one of them refers to the state of the sample to be analyzed when being sampled, which 'alter' during the time elapsed from sampling up to the analysis of the sample. The other impediment is the natural change of the dispersion state of the standard radioactive solutions, due to the occurrence and evolution in time of the radiocolloidal and pseudo-radiocolloidal states. These radiocolloidal states are states of aggregation and they lead to the destruction of the homogeneity of the solutions. Taking into consideration the advantages offered by the relative physical methods of analysis as against the chemical or the radiochemical ones, different ways of eliminating these impediments have been tried. We eliminated these impediments processing the liquid reference materials (the solutions calibrated in radionuclides of interest), immediately after the preparation. This processing changes the liquid physical state of the reference materials in a 'solidified state'. Through this procedure the dispersion states of the samples, practically, can no longer be essentially modified in time and also ensure the uniform distribution of the radionuclides of interest in the elemental matrix of the samples 'state solidified'. The homogeneity of the distribution of the atoms of the radionuclides from the samples 'solidified state' was checked up through the track micromapping technique of the alpha particles. Through this technique, in the chemically etched track detectors that were put in direct contact with the sample for a determined period of time, the alpha exposure time of the detectors, micromaps of alpha tracks were obtained. These micromaps are retorts through tracks of the distributions atoms of fissionable elements (Thorium e.g.), of which, heavy charged particles, in this case the alpha radiations naturally emitted, were registered in the CR-39 track detectors. The density of alpha track from the obtained track micromaps was studied through common optic microscopy. Micromaps were studied counting the tracks on equal areas, in different measurement points. For the study of the foils prepared within the paper, the studied area was of 4.9 mm2, formed of 10 fields of 0.49 mm2 area each. The estimation of the uncertainty was carried out for all the sizes that were measured within the paper, no matter if they participate, directly or indirectly, in the estimation of the uncertainty regarding the homogeneity of the Thorium atoms distribution in the 'solidified state' foils of the standard solution calibrated in Thorium, such as: i) the weighted masses, ii) the dropped volumes of solution, iii) the alpha duration of exposure of the detectors, iv) the area studied on the surface of the micromap and v) the densities of alpha tracks. The procedure suggested allowed us to considerate that the homogeneity of alpha tracks distribution, on the surface and in thickness, is within the limits of 3.1%.

  18. Ternary Fission of 249Cf(n,f) and 250Cf(SF)

    E-Print Network [OSTI]

    , S. Vermote

    2013-01-01T23:59:59.000Z

    +b. INTRODUCTION Nuclear fission is essentially a binaryternary fission data are of interest for nuclear physics innuclear reactors and also in used fuel elements due to spontaneous fission.

  19. Latent ion tracks in amorphous silicon

    SciTech Connect (OSTI)

    Bierschenk, Thomas [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Giulian, Raquel [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Afra, Boshra [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Rodriguez, Matias D [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Schauries, D [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Mudie, Stephen [Australian Synchrotron] [Australian Synchrotron; Pakarinen, Olli H [ORNL] [ORNL; Djurabekova, Flyura [University of Helsinki] [University of Helsinki; Nordlund, Kai [University of Helsinki] [University of Helsinki; Osmani, Orkhan [University of Duisburg-Essen, Germany] [University of Duisburg-Essen, Germany; Medvedev, Nikita [University of Kaiserslautern, Germany] [University of Kaiserslautern, Germany; Rethfield, Baerbel [University of Kaiserslautern, Germany] [University of Kaiserslautern, Germany; Ridgway, Mark C [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia; Kluth, Patrick [Australian National University, Canberra, Australia] [Australian National University, Canberra, Australia

    2013-01-01T23:59:59.000Z

    We present experimental evidence for the formation of ion tracks in amorphous Si induced by swift heavy ion irradiation. An underlying core-shell structure consistent with remnants of a high density liquid structure was revealed by small-angle x-ray scattering and molecular dynamics simulations. Ion track dimensions dier for as-implanted and relaxed Si as attributed to dierent microstructures and melting temperatures. The identication and characterisation of ion tracks in amorphous Si yields new insight into mechanisms of damage formation due to swift heavy ion irradiation in amorphous semiconductors.

  20. Microscopic Description of Nuclear Fission: Fission Barrier Heights of Even-Even Actinides

    E-Print Network [OSTI]

    J. McDonnell; N. Schunck; W. Nazarewicz

    2013-01-31T23:59:59.000Z

    We evaluate the performance of modern nuclear energy density functionals for predicting inner and outer fission barrier heights and energies of fission isomers of even-even actinides. For isomer energies and outer barrier heights, we find that the self-consistent theory at the HFB level is capable of providing quantitative agreement with empirical data.

  1. Track 2: Worker Engagement

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 2: Worker Engagement

  2. Track 3: Exposure Hazards

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 3: Exposure Hazards

  3. Track 9: Quality Assurance

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 9: Quality Assurance

  4. Fusion-Fission of 16O+197Au at Sub-Barrier Energies

    E-Print Network [OSTI]

    B. B. Back; C. L. Jiang; R. V. F. Janssens; D. J. Henderson; B. R. Shumard; C. J. Lister; D. Peterson; K. E. Rehm; I. Tanihata; X. Tang; X. Wang; S. Zhu

    2006-06-06T23:59:59.000Z

    The recent discovery of heavy-ion fusion hindrance at far sub-barrier energies has focused much attention on both experimental and theoretical studies of this phenomenon. Most of the experimental evidence comes from medium-heavy systems such as Ni+Ni to Zr+Zr, for which the compound system decays primarily by charged-particle evaporation. In order to study heavier systems, it is, however, necessary to measure also the fraction of the decay that goes into fission fragments. In the present work we have, therefore, measured the fission cross section of 16O+197Au down to unprecedented far sub-barrier energies using a large position sensitive PPAC placed at backward angles. The preliminary cross sections will be discussed and compared to earlier studies at near-barrier energies. No conclusive evidence for sub-barrier hindrance was found, probably because the measurements were not extended to sufficiently low energies.

  5. Dissipative dynamics in quasi-fission

    E-Print Network [OSTI]

    V. E. Oberacker; A. S. Umar; C. Simenel

    2014-09-10T23:59:59.000Z

    Quasi-fission is the primary reaction mechanism that prevents the formation of superheavy elements in heavy-ion fusion experiments. Employing the time-dependent density functional theory approach we study quasi-fission in the systems $^{40,48}$Ca+$^{238}$U. Results show that for $^{48}$Ca projectiles the quasi-fission is substantially reduced in comparison to the $^{40}$Ca case. This partly explains the success of superheavy element formation with $^{48}$Ca beams. For the first time, we also calculate the repartition of excitation energies of the two fragments in a dynamic microscopic theory. The system is found in quasi-thermal equilibrium only for reactions with $^{40}$Ca. The differences between both systems are interpreted in terms of initial neutron to proton asymmetry of the colliding partners.

  6. Phase Transition Induced Fission in Lipid Vesicles

    E-Print Network [OSTI]

    C. Leirer; B. Wunderlich; V. M. Myles; M. F. Schneider

    2010-05-24T23:59:59.000Z

    In this work we demonstrate how the first order phase transition in giant unilamellar vesicles (GUVs) can function as a trigger for membrane fission. When driven through their gel-fluid phase transition GUVs exhibit budding or pearl formation. These buds remain connected to the mother vesicle presumably by a small neck. Cooling these vesicles from the fluid phase (T>Tm) through the phase transition into the gel state (Tfission of the neck, while the mother vesicle remains intact. Pearling tubes which formed upon heating break-up and decay into multiple individual vesicles which then diffuse freely. Finally we demonstrate that mimicking the intracellular bulk viscosity by increasing the bulk viscosity to 40cP does not affect the overall fission process, but leads to a significant decrease in size of the released vesicles.

  7. Fission Barriers of Compound Superheavy Nuclei

    E-Print Network [OSTI]

    J. C. Pei; W. Nazarewicz; J. A. Sheikh; A. K. Kerman

    2009-02-27T23:59:59.000Z

    The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. In this work, we investigate the isentropic fission barriers by means of the self-consistent nuclear density functional theory. The relationship between isothermal and isentropic descriptions is demonstrated. Calculations have been carried out for $^{264}$Fm, $^{272}$Ds, $^{278}$112, $^{292}$114, and $^{312}$124. For nuclei around $^{278}$112 produced in "cold fusion" reactions, we predict a more rapid decrease of fission barriers with excitation energy as compared to the nuclei around $^{292}$114 synthesized in "hot fusion" experiments. This is explained in terms of the difference between the ground-state and saddle-point temperatures. The effect of the particle gas is found to be negligible in the range of temperatures studied.

  8. affordable fission surface: Topics by E-print Network

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

    Pal, S; Pal, Santanu; Mukhopadhyay, Tapan 1998-01-01 9 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  9. amount gaseous fission: Topics by E-print Network

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

    17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  10. asymmetric fission barriers: Topics by E-print Network

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

    remains unchanged T. K. Ghosh; P. Bhattacharya 2005-05-15 47 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  11. absolute fission yields: Topics by E-print Network

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

    compared with the experimental data. Warda, M 2015-01-01 29 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  12. achieve comparable fission: Topics by E-print Network

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

    that. H. Abusara; A. V. Afanasjev; P. Ring 2010-10-09 9 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  13. actinide nuclei fission: Topics by E-print Network

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

    materials can be utilized. Hirokazu Maruyama 2007-11-20 122 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  14. accompanied ternary fission: Topics by E-print Network

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

    2, it i.e. Aii2. Gennady Volkov 2010-06-29 25 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  15. asymmetrical fission type: Topics by E-print Network

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

    J. A. Sheikh; A. Staszczak; M. Warda 2014-06-26 27 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  16. applications fission neutrons: Topics by E-print Network

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

    T. Z. Yan; C. Zhong; X. F. Zhou; J. X. Zuo 2004-12-09 105 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  17. alpha particle fission: Topics by E-print Network

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

    A. Daleo; C. A. Garca Canal; R. Sassot 2003-03-24 131 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  18. absolute thermal fission: Topics by E-print Network

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

    emitted by the fragments. W. Younes; D. Gogny 2009-10-09 28 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  19. active inspection fission: Topics by E-print Network

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

    K. Tittelmeier; D. Vartsky; H. Wershofen 2012-01-04 12 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  20. Uncertainty Quantification on Prompt Fission Neutrons Spectra

    SciTech Connect (OSTI)

    Talou, P. [T-16, Nuclear Physics Group, Los Alamos National Laboratory, NM 87545 (United States)], E-mail: talou@lanl.gov; Madland, D.G.; Kawano, T. [T-16, Nuclear Physics Group, Los Alamos National Laboratory, NM 87545 (United States)

    2008-12-15T23:59:59.000Z

    Uncertainties in the evaluated prompt fission neutrons spectra present in ENDF/B-VII.0 are assessed in the framework of the Los Alamos model. The methodology used to quantify the uncertainties on an evaluated spectrum is introduced. We also briefly review the Los Alamos model and single out the parameters that have the largest influence on the calculated results. Using a Kalman filter, experimental data and uncertainties are introduced to constrain model parameters, and construct an evaluated covariance matrix for the prompt neutrons spectrum. Preliminary results are shown in the case of neutron-induced fission of {sup 235}U from thermal up to 15 MeV incident energies.

  1. Reexamination of fission fragment angular distributions and the fission process: Formalism

    SciTech Connect (OSTI)

    Bond, P.D.

    1985-08-01T23:59:59.000Z

    The theory of fission fragment angular distributions is examined and the universally used expression is found to be valid only under restrictive assumptions. A more general angular distribution formula is derived and applied to recent data of high spin systems. At the same time it is shown that the strong anisotropies observed from such systems can be understood without changing the essential basis of standard fission theory. The effects of reaction mechanisms other than complete fusion on fission fragment angular distributions are discussed and possible angular distribution signatures of noncompound nucleus formation are mentioned.

  2. Optimally moderated nuclear fission reactor and fuel source therefor

    DOE Patents [OSTI]

    Ougouag, Abderrafi M. (Idaho Falls, ID); Terry, William K. (Shelley, ID); Gougar, Hans D. (Idaho Falls, ID)

    2008-07-22T23:59:59.000Z

    An improved nuclear fission reactor of the continuous fueling type involves determining an asymptotic equilibrium state for the nuclear fission reactor and providing the reactor with a moderator-to-fuel ratio that is optimally moderated for the asymptotic equilibrium state of the nuclear fission reactor; the fuel-to-moderator ratio allowing the nuclear fission reactor to be substantially continuously operated in an optimally moderated state.

  3. General view on nuclear fission Karl-Heinz Schmidt

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    General view on nuclear fission Karl-Heinz Schmidt Beatriz Jurado CENBG, CNRS/IN2 P3 Chemin du.amouroux@cea.fr 1 in2p3-00976648,version1-10Apr2014 #12;Abstract: A general approach to nuclear fission is described which ex- plains the complex appearance of fission observables by universal principles of theoretical

  4. Fission Characteristics of Heavy Nuclei: Statics and Dynamics

    E-Print Network [OSTI]

    Birger B. Back

    1999-06-14T23:59:59.000Z

    This paper presents a selective historical perspective of fission research over the last thirty-five years while Ray Nix has made central contributions to the field. The emphasis is placed on early studies of the shell stabilized secondary minimum in the static fission barrier and on the dynamic properties of fission of hot nuclei, which have recently been the focus of intense study.

  5. Track Co-ordinators Guide Track Co-ordinators Guide

    E-Print Network [OSTI]

    Track Co-ordinators Guide CERN #12;Track Co-ordinators Guide by CERN #12;Table of Contents 1. Track Co-ordinators Guide ..................................................................................................................1 1.1. Track Co

  6. Direct Evidence of Washing out of Nuclear Shell Effects

    E-Print Network [OSTI]

    Chaudhuri, A; Banerjee, K; Bhattacharya, S; Sadhukhan, Jhilam; Bhattacharya, C; Kundu, S; Meena, J K; Mukherjee, G; Pandey, R; Rana, T K; Roy, P; Roy, T; Srivastava, V; Bhattacharya, P

    2015-01-01T23:59:59.000Z

    Constraining excitation energy at which nuclear shell effect washes out has important implications on the production of super heavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in alpha induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that nuclear shell effect washes out at excitation energy ~40 MeV. Calculation shows that second peak of the ?fission barrier also vanishes around similar excitation energy.

  7. Direct Evidence of Washing out of Nuclear Shell Effects

    E-Print Network [OSTI]

    A. Chaudhuri; T. K. Ghosh; K. Banerjee; S. Bhattacharya; Jhilam Sadhukhan; C. Bhattacharya; S. Kundu; J. K. Meena; G. Mukherjee; R. Pandey; T. K. Rana; P. Roy; T. Roy; V. Srivastava; P. Bhattacharya

    2015-04-17T23:59:59.000Z

    Constraining excitation energy at which nuclear shell effect washes out has important implications on the production of super heavy elements and many other fields of nuclear physics research. We report the fission fragment mass distribution in alpha induced reaction on an actinide target for wide excitation range in close energy interval and show direct evidence that nuclear shell effect washes out at excitation energy ~40 MeV. Calculation shows that second peak of the ?fission barrier also vanishes around similar excitation energy.

  8. Fission barriers and probabilities of spontaneous fission for elements with Z$\\geq$100

    E-Print Network [OSTI]

    Baran, A; Reinhard, P -G; Robledo, L M; Staszczak, A; Warda, M

    2015-01-01T23:59:59.000Z

    This is a short review of methods and results of calculations of fission barriers and fission half-lives of even-even superheavy nuclei. An approvable agreement of the following approaches is shown and discussed: The macroscopic-microscopic approach based on the stratagem of the shell correction to the liquid drop model and a vantage point of microscopic energy density functionals of Skyrme and Gogny type selfconsistently calculated within Hartree-Fock-Bogoliubov method. Mass parameters are calculated in the Hartree-Fock-Bogoliubov cranking approximation. A short part of the paper is devoted to the nuclear fission dynamics. We also discuss the predictive power of Skyrme functionals applied to key properties of the fission path of $^{266}$Hs. It applies the standard techniques of error estimates in the framework of a $\\chi^2$ analysis.

  9. Prompt muon-induced fission: a sensitive probe for nuclear energy dissipation and fission dynamics

    E-Print Network [OSTI]

    Volker E. Oberacker; A. Sait Umar; Feodor F. Karpeshin

    2004-03-30T23:59:59.000Z

    Following the formation of an excited muonic atom, inner shell transitions may proceed without photon emission by inverse internal conversion, i.e. the muonic excitation energy is transferred to the nucleus. In actinides, the 2p -> 1s and the 3d -> 1s muonic transitions result in excitation of the nuclear giant dipole and giant quadrupole resonances, respectively, which act as doorway states for fission. The nuclear excitation energy is typically 6.5 - 10 MeV. Because the muon lifetime is long compared to the timescale of prompt nuclear fission, the motion of the muon in the Coulomb field of the fissioning nucleus may be utilized to learn about the dynamics of fission.

  10. Fission barriers and probabilities of spontaneous fission for elements with Z$\\geq$100

    E-Print Network [OSTI]

    A. Baran; M. Kowal; P. -G. Reinhard; L. M. Robledo; A. Staszczak; M. Warda

    2015-03-05T23:59:59.000Z

    This is a short review of methods and results of calculations of fission barriers and fission half-lives of even-even superheavy nuclei. An approvable agreement of the following approaches is shown and discussed: The macroscopic-microscopic approach based on the stratagem of the shell correction to the liquid drop model and a vantage point of microscopic energy density functionals of Skyrme and Gogny type selfconsistently calculated within Hartree-Fock-Bogoliubov method. Mass parameters are calculated in the Hartree-Fock-Bogoliubov cranking approximation. A short part of the paper is devoted to the nuclear fission dynamics. We also discuss the predictive power of Skyrme functionals applied to key properties of the fission path of $^{266}$Hs. It applies the standard techniques of error estimates in the framework of a $\\chi^2$ analysis.

  11. Fission and quasi-fission: insights into heavy element formation reactions

    SciTech Connect (OSTI)

    Hinde, D. J.; Rietz, R. du; Rafiei, R.; Dasgupta, M.; Diaz-Torres, A. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); Thomas, R. G. [Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 0200 (Australia); B.A.R.C., Mumbai (India)

    2009-03-04T23:59:59.000Z

    Mass-angle distributions carry detailed information on the characteristics of quasi-fission, and thus of the dynamics of heavy element formation reactions. Recent experimental results are presented and discussed.

  12. FISSION REACTORS KEYWORDS: core-barrel vibra-

    E-Print Network [OSTI]

    Demazière, Christophe

    FISSION REACTORS KEYWORDS: core-barrel vibra- tions, in-core neutron noise, shell- mode vibrations CALCULATION OF THE NEUTRON NOISE INDUCED BY SHELL-MODE CORE-BARREL VIBRATIONS IN A 1-D, TWO-GROUP, TWO-REGION SLAB REACTOR MODEL CARL SUNDE,* CHRISTOPHE DEMAZI�RE, and IMRE PÁZSIT Chalmers University of Technology

  13. The Fission of thorium with Alpha Particles

    E-Print Network [OSTI]

    Newton, Amos S.

    2010-01-01T23:59:59.000Z

    a,aAo! o6 10'n J .L. THiCKNESS THORIUM IN mg/cm 2 FIG.FISSION PRODUCTS FROM THORIUM +-HELIUM IONS FIG 3 EXCITATiONOF GROSS BETA ACTIVITY IN THORIUM TARGE~I uJ g :J 20 uJ :l:

  14. Liquid uranium alloy-helium fission reactor

    DOE Patents [OSTI]

    Minkov, Vladimir (Skokie, IL)

    1986-01-01T23:59:59.000Z

    This invention teaches a nuclear fission reactor having a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200.degree.-1800.degree. C. range, and even higher to 2500.degree. C., limited only by the thermal effectiveness of the structural materials, increasing the efficiency of power generation from the normal 30-35% with 300.degree.-500.degree. C. upper limit temperature to 50-65%. Irradiation of the circulating liquid fuel, as contrasted to only localized irradiation of a solid fuel, provides improved fuel utilization.

  15. Liquid uranium alloy-helium fission reactor

    DOE Patents [OSTI]

    Minkov, V.

    1984-06-13T23:59:59.000Z

    This invention describes a nuclear fission reactor which has a core vessel and at least one tandem heat exchanger vessel coupled therewith across upper and lower passages to define a closed flow loop. Nuclear fuel such as a uranium alloy in its liquid phase fills these vessels and flow passages. Solid control elements in the reactor core vessel are adapted to be adjusted relative to one another to control fission reaction of the liquid fuel therein. Moderator elements in the other vessel and flow passages preclude fission reaction therein. An inert gas such as helium is bubbled upwardly through the heat exchanger vessel operable to move the liquid fuel upwardly therein and unidirectionally around the closed loop and downwardly through the core vessel. This helium gas is further directed to heat conversion means outside of the reactor vessels to utilize the heat from the fission reaction to generate useful output. The nuclear fuel operates in the 1200 to 1800/sup 0/C range, and even higher to 2500/sup 0/C.

  16. Fission Fragment Distributions and Delayed Neutron Yields from Photon-Induced-Fission

    SciTech Connect (OSTI)

    David, J.-C.; Dore, D.; Giacri-Mauborgne, M.-L.; Ridikas, D.; Lauwe, A. van [DSM/DAPNIA/SPhN, CEA/Saclay, F-91191 Gif-sur-Yvette cedex (France)

    2005-05-24T23:59:59.000Z

    Fission fragment distributions and delayed neutron yields for 235U and 238U are provided by a complete modelization of the photofission process below 25 MeV. The absorption cross-section parameterization and the fission fragment distributions are given and compared to experimental data. The delayed neutron yields and the half-lives in terms of six groups are presented and compared to data obtained with a bremsstrahlung spectrum of 15 MeV.

  17. Solar tracking apparatus

    DOE Patents [OSTI]

    Hammons, Burrell E. (Albuquerque, NM)

    1980-01-01T23:59:59.000Z

    The invention relates to a solar tracking device which tracks the position of the sun using paired, partially-shaded photocells. Auxiliary photocells are used for initial acquisition of the sun and for the suppression of false tracking when the sun is obscured by clouds.

  18. Induction of nuclear fission by high-voltage application

    E-Print Network [OSTI]

    Hirokazu Maruyama

    2007-11-20T23:59:59.000Z

    In nuclear power generation, fissile materials are mainly used. For example, $U^{235}$ is fissile and therefore quite essential for use of nuclear energy. However, the material $U^{235}$ has very small natural abundance less than 1 %. We should seek possibility of utilizing fissionable materials such as $U^{238}$ because natural abundance of such fissionable materials is generally much larger than fissile ones. In this paper, we show that thermal neutrons with vanishing kinetic energy can induce nuclear fission when high voltage is applied to fissionable materials. To obtain this result, we use the liquid-drop model for nuclei. Finally, we propose how fissionable materials can be utilized.

  19. Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry

    SciTech Connect (OSTI)

    Irina Glagolenko; Bruce Hilton; Jeffrey Giglio; Daniel Cummings; Karl Grimm; Richard McKnight

    2009-11-01T23:59:59.000Z

    Correct prediction of the fission products inventory in irradiated nuclear fuels is essential for accurate estimation of fuel burnup, establishing proper requirements for spent fuel transportation and storage, materials accountability and nuclear forensics. Such prediction is impossible without accurate knowledge of neutron induced fission yields. Unfortunately, the accuracy of the fission yields reported in the ENDF/B-VII.0 library is not uniform across all of the data and much of the improvement is desired for certain isotopes and fission products. We discuss our measurements of cumulative fission yields in nuclear fuels irradiated in thermal and fast reactor spectra using Inductively Coupled Plasma Mass Spectrometry.

  20. Conservation of Isospin in Neutron-Rich Fission Fragments

    E-Print Network [OSTI]

    Ashok Kumar Jain; Deepika Choudhury; Bhoomika Maheshwari

    2014-08-11T23:59:59.000Z

    On the occasion of the $75^{th}$ anniversary of the fission phenomenon, we present a surprisingly simple result which highlights the important role of isospin and its conservation in neutron rich fission fragments. We have analysed the fission fragment mass distribution from two recent heavy-ion reactions $^{238}$U($^{18}$O,f) and $^{208}$Pb($^{18}$O,f) as well as a thermal neutron fission reaction $^{245}$Cm(n$^{th}$,f). We find that the conservation of the total isospin explains the overall trend in the observed relative yields of fragment masses in each fission pair partition. The isospin values involved are very large making the effect dramatic. The findings open the way for more precise calculations of fission fragment distributions in heavy nuclei and may have far reaching consequences for the drip line nuclei, HI fusion reactions, and calculation of decay heat in the fission phenomenon.

  1. Muon Tracking to Detect Special Nuclear Materials

    SciTech Connect (OSTI)

    Schwellenbach, D. [NSTec; Dreesen, W. [NSTec; Green, J. A. [NSTec; Tibbitts, A. [NSTec; Schotik, G. [NSTec; Borozdin, K. [LANL; Bacon, J. [LANL; Midera, H. [LANL; Milner, C. [LANL; Morris, C. [LANL; Perry, J. [LANL; Barrett, S. [UW; Perry, K. [UW; Scott, A. [UW; Wright, C. [UW; Aberle, D. [NSTec

    2013-03-18T23:59:59.000Z

    Previous experiments have proven that nuclear assemblies can be imaged and identified inside of shipping containers using vertical trajectory cosmic-ray muons with two-sided imaging. These experiments have further demonstrated that nuclear assemblies can be identified by detecting fission products in coincidence with tracked muons. By developing these technologies, advanced sensors can be designed for a variety of warhead monitoring and detection applications. The focus of this project is to develop tomographic-mode imaging using near-horizontal trajectory muons in conjunction with secondary particle detectors. This will allow imaging in-situ without the need to relocate the objects and will enable differentiation of special nuclear material (SNM) from other high-Z materials.

  2. Fusion-fission energy systems evaluation

    SciTech Connect (OSTI)

    Teofilo, V.L.; Aase, D.T.; Bickford, W.E.

    1980-01-01T23:59:59.000Z

    This report serves as the basis for comparing the fusion-fission (hybrid) energy system concept with other advanced technology fissile fuel breeding concepts evaluated in the Nonproliferation Alternative Systems Assessment Program (NASAP). As such, much of the information and data provided herein is in a form that meets the NASAP data requirements. Since the hybrid concept has not been studied as extensively as many of the other fission concepts being examined in NASAP, the provided data and information are sparse relative to these more developed concepts. Nevertheless, this report is intended to provide a perspective on hybrids and to summarize the findings of the rather limited analyses made to date on this concept.

  3. Fission of a multiphase membrane tube

    E-Print Network [OSTI]

    Jean-Marc Allain; Cornelis Storm; Aurelien Roux; Martine Ben Amar; Jean-Francois Joanny

    2004-09-01T23:59:59.000Z

    A common mechanism for intracellular transport is the use of controlled deformations of the membrane to create spherical or tubular buds. While the basic physical properties of homogeneous membranes are relatively well-known, the effects of inhomogeneities within membranes are very much an active field of study. Membrane domains enriched in certain lipids in particular are attracting much attention, and in this Letter we investigate the effect of such domains on the shape and fate of membrane tubes. Recent experiments have demonstrated that forced lipid phase separation can trigger tube fission, and we demonstrate how this can be understood purely from the difference in elastic constants between the domains. Moreover, the proposed model predicts timescales for fission that agree well with experimental findings.

  4. Fission-product-decay characteristics. Master's thesis

    SciTech Connect (OSTI)

    Millage, K.K.

    1989-03-01T23:59:59.000Z

    This theses determined fission-product decay characteristics , including the total activity, the gamma-ray emission rate (GER) and gamma-ray energy spectra. The activity and GER decay were compared to Way and Wigner's t(exp(-1.2)) approximation, and the effects the spectra, activity, and GER have on the Source Normalization Constant (K) were examined. Most of the fission-product data were obtained from DKPOWR, and were compared with data obtained from ORIGIN2. Since the gamma rays are of primary concern in fallout studies, the GER is used instead of activity. The ratio of GER to activity changes significantly with time. Results of this study calculate a GER of 590 x 10/sup 16/ gamma rays/second per kT of fission yield from U-235 fuel and a K of 7059 R/Hr/(kT/sq.km.). The calculation of K includes the contribution from scattered photons. The GER result is 11% higher than reference values, while the K is within 2% of the current value in Glasstone and Dolan's The Effects of Nuclear Weapons. The Ks for Pu-239 and U-238 were within 5% of the U-235 results. The wax-wigners t(exp(-1.2)) approximation differs from time dependent GER and K up to 85% for times less than 6 months. The approximation is not valid for the GER or K at times greater than 6 months. The approximation is within about 45%, for the activity from fission-product decay to at least 5 years. A more accurate measure of exposure requires a numerical integration of the time dependent GER and Source Normalization Constant.

  5. Accurate fission data for nuclear safety

    E-Print Network [OSTI]

    Solders, A; Jokinen, A; Kolhinen, V S; Lantz, M; Mattera, A; Penttila, H; Pomp, S; Rakopoulos, V; Rinta-Antila, S

    2013-01-01T23:59:59.000Z

    The Accurate fission data for nuclear safety (AlFONS) project aims at high precision measurements of fission yields, using the renewed IGISOL mass separator facility in combination with a new high current light ion cyclotron at the University of Jyvaskyla. The 30 MeV proton beam will be used to create fast and thermal neutron spectra for the study of neutron induced fission yields. Thanks to a series of mass separating elements, culminating with the JYFLTRAP Penning trap, it is possible to achieve a mass resolving power in the order of a few hundred thousands. In this paper we present the experimental setup and the design of a neutron converter target for IGISOL. The goal is to have a flexible design. For studies of exotic nuclei far from stability a high neutron flux (10^12 neutrons/s) at energies 1 - 30 MeV is desired while for reactor applications neutron spectra that resembles those of thermal and fast nuclear reactors are preferred. It is also desirable to be able to produce (semi-)monoenergetic neutrons...

  6. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    it is unlikely that nuclear fission power plants willIn the case of nuclear fission reactions, the fundamentalaspects of nuclear fusion and fission. This approach, termed

  7. HEAVY-ION-INDUCED TERNARY FISSION AS A PROBE OF THE DYNAMICAL DECAY OF

    E-Print Network [OSTI]

    de Souza, Romualdo T.

    of Nuclear Fission Dynamics . . . . . . . . . . . . . . . . . . 5 1.2.1 Total Kinetic Energy of the Fission of Ternary Fission . . . . . . . . . . . . . . 11 1.4 Models of Nuclear FissionHEAVY-ION-INDUCED TERNARY FISSION AS A PROBE OF THE DYNAMICAL DECAY OF EXCITED NUCLEI Todd A

  8. Exotic fission properties of highly neutron-rich Uranium isotopes

    E-Print Network [OSTI]

    L. Satpathy; S. K. Patra; R. K. Choudhury

    2007-03-05T23:59:59.000Z

    The series of Uranium isotopes with $N=154 \\sim 172$ around the magic number N=162/164 are identified to be thermally fissile. The thermal neutron fission of a typical representative $^{249}$U of this region amenable to synthesis in the radioactive ion beam facilities is considered here. Semiempirical study of fission barrier height and width shows this nucleus to be infinitely stable against spontaneous fission due to increase in barrier width arising out of excess neutrons. Calculation of probability of fragment mass yields and microscopic study in relativistic mean field theory, show this nucleus to undergo a new mode of thermal fission decay termed {\\it multifragmentation fission} where a number of prompt scission neutrons are simultaneously released along with the two heavy fission fragments.

  9. Sharp change over from compound nuclear fission to shape dependent quasi fission

    E-Print Network [OSTI]

    T. K. Ghosh; K. Banerjee; C. Bhattacharya; S. Bhattacharya; S. Kundu; P. Mali; J. K. Meena; G. Mukherjee; S. Mukhopadhyay; T. K. Rana; P. Bhattacharya; K. S. Golda

    2008-09-17T23:59:59.000Z

    Fission fragment mass distribution has been measured from the decay of $^{246}$Bk nucleus populating via two entrance channels with slight difference in mass asymmetries but belonging on either side of the Businaro Gallone mass asymmetry parameter. Both the target nuclei were deformed. Near the Coulomb barrier, at similar excitation energies the width of the fission fragment mass distribution was found to be drastically different for the $^{14}$N + $^{232}$Th reaction compared to the $^{11}$B + $^{235}$U reaction. The entrance channel mass asymmetry was found to affect the fusion process sharply.

  10. On "Sub-Threshold" Reactions Involving Nuclear Fission

    E-Print Network [OSTI]

    M. Goldhaber; R. Shrock

    2000-11-29T23:59:59.000Z

    We analyze reactions of several types that are naively below threshold but can proceed because of the release of binding energy from nuclear fission and occasionally the formation of Coulombic bound states. These reactions include (i) photofission with pion production and (ii) charged current neutrino-nucleus reactions that lead to fission and/or formation of a Coulomb bound state of a $\\mu^-$ with the nucleus of a fission fragment. We comment on the possible experimental observation of these reactions.

  11. Proton induced fission of 181-Ta at relativistic energies

    E-Print Network [OSTI]

    Y. Ayyad; J. Benlliure; E. Casarejos; H. Álvarez-Pol; A. Bacquias; A. Boudard; M. Caamaño; T. Enqvist; V. Föhr; A. Keli?-Heil; K. Kezzar; S. Leray; C. Paradela; D. Pérez-Loureiro; R. Pleska?; D. Tarrío

    2012-03-07T23:59:59.000Z

    Total fission cross sections of 181-Ta induced by protons at different relativistic energies have been measured at GSI, Darmstadt. The inverse kinematics technique used together with a dedicated set-up, made it possible to determine these cross sections with high accuracy. The new data obtained in this experiment will contribute to the understanding of the fission process at high excitation energies. The results are compared with data from previous experiments and systematics for proton-induced fission cross sections.

  12. Fission studies with 140 MeV $\\bm?$-Particles

    E-Print Network [OSTI]

    A. Buttkewitz; H. H. Duhm; F. Goldenbaum; H. Machner; W. Strauss

    2009-07-23T23:59:59.000Z

    Binary fission induced by 140 MeV $\\alpha$-particles has been measured for $^{\\rm nat}$Ag, $^{139}$La, $^{165}$Ho and $^{197}$Au targets. The measured quantities are the total kinetic energies, fragment masses, and fission cross sections. The results are compared with other data and systematics. A minimum of the fission probability in the vicinity $Z^2/A=24$ is observed.

  13. Exciton Dynamics and Structural Investigations of Singlet Fission...

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

    Exciton Dynamics and Structural Investigations of Singlet Fission in Molecular Solids October 11, 2012 at 3pm36-428 Michael R. Wasielewski Director, Argonne-Northwestern Solar...

  14. Most Viewed Documents for Fission and Nuclear Technologies: December...

    Office of Scientific and Technical Information (OSTI)

    various two-phase flow regimes Ishii, M. (1977) 20 3rd Miami international conference on alternative energy sources Nejat Veziroglu, T. (1980) 19 Fission fragment rockets: A...

  15. Spontaneous fission half-lives for ground state nuclides

    SciTech Connect (OSTI)

    Holden, N.E. [Brookhaven National Lab., Upton, NY (United States); Hoffman, D.C. [Lawrence Berkeley Lab., CA (United States)

    1993-08-01T23:59:59.000Z

    Measurements of the spontaneous fission half-lives of nuclides of elements Z = 90 to 108 have been compiled and evaluated. Recommended values are presented.

  16. Time dependence of delayed neutron emission for fissionable isotope identification

    SciTech Connect (OSTI)

    Kinlaw, M.T.; Hunt, A.W. [Idaho Accelerator Center, Idaho State University, Pocatello, Idaho 83209-8263 (United States); Department of Physics, Idaho State University, Pocatello, Idaho 83209-8106 (United States)

    2005-06-20T23:59:59.000Z

    The time dependence of delayed neutron emission was examined as a method of fissionable isotope identification. A pulsed bremsstrahlung photon beam was used to induce photofission reactions in {sup 238}U, {sup 232}Th, and {sup 239}Pu targets. The resulting delayed neutron emission was recorded between irradiating pulses and is a well-known technique for fissionable material detection. Monitoring the decay of delayed neutron emission between irradiating pulses demonstrates the ability to not only detect the presence of fissionable materials, but also to identify which fissionable isotope is present.

  17. Singlet Exciton Fission in Polyacenes: Photophysics and Photovoltaic...

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

    Exciton Fission in Polyacenes: Photophysics and Photovoltaic Applications December 13, 2011 at 3pm34-401A Mark Wilson Optoelectronics Group, University of Cambridge...

  18. Uncertainties analysis of fission fraction for reactor antineutrino experiments

    E-Print Network [OSTI]

    X. B. Ma; F. Lu; L. Z. Wang; Y. X. Chen; W. L. Zhong; F. P. An

    2015-03-17T23:59:59.000Z

    Reactor antineutrino experiment are used to study neutrino oscillation, search for signatures of nonstandard neutrino interaction, and monitor reactor operation for safeguard application. Reactor simulation is an important source of uncertainties for a reactor neutrino experiment. Commercial code is used for reactor simulation to evaluate fission fraction in Daya Bay neutrino experiment, but the source code doesn't open to our researcher results from commercial secret. In this study, The open source code DRAGON was improved to calculate the fission rates of the four most important isotopes in fissions, $^{235}$U,$^{238}$U,$^{239}$Pu and $^{241}$Pu, and then was validated for PWRs using the Takahama-3 benchmark. The fission fraction results are consistent with those of MIT's results. Then, fission fraction of Daya Bay reactor core was calculated by using improved DRAGON code, and the fission fraction calculated by DRAGON agreed well with these calculated by SCIENCE. The average deviation less than 5\\% for all the four isotopes. The correlation coefficient matrix between $^{235}$U,$^{238}$U,$^{239}$Pu and $^{241}$Pu were also studied using DRAGON, and then the uncertainty of the antineutrino flux by the fission fraction was calculated by using the correlation coefficient matrix. The uncertainty of the antineutrino flux by the fission fraction simulation is 0.6\\% per core for Daya Bay antineutrino experiment. The uncertainties source of fission fraction calculation need further to be studied in the future.

  19. Large scale tracking algorithms.

    SciTech Connect (OSTI)

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01T23:59:59.000Z

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  20. Characterization of a Stochastic Procedure for the Generation and Transport of Fission Fragments within Nuclear Fuels

    E-Print Network [OSTI]

    Hackemack, Michael Wayne

    2013-04-15T23:59:59.000Z

    , for generating individual fission event result channels and analyzing their specific response in the fuel. We utilized the nuclear reaction simulation tool, TALYS, to generate energy-dependent fission fragment yield distributions for different fissile/fissionable...

  1. Fission barrier, damping of shell correction and neutron emission in the fission of A$\\sim$200

    E-Print Network [OSTI]

    Mahata, K; Kapoor, S S

    2015-01-01T23:59:59.000Z

    Decay of $^{210}$Po compound nucleus formed in light and heavy-ion induced fusion reactions has been analyzed simultaneously using a consistent prescription for fission barrier and nuclear level density incorporating shell correction and its damping with excitation energy. Good description of all the excitation functions have been achieved with a fission barrier of 21.9 $\\pm$ 0.2 MeV. For this barrier height, the predicted statistical pre-fission neutrons in heavy-ion fusion-fission are much smaller than the experimental values, implying the presence of dynamical neutrons due to dissipation even at these low excitation energies ($\\sim$ 50~MeV) in the mass region A $\\sim$ 200. When only heavy-ion induced fission excitation functions and the pre-fission neutron multiplicities are included in the fits, the deduced best fit fission barrier depends on the assumed fission delay time during which dynamical neutrons can be emitted. A fission delay of (0.8 $\\pm$ 0.1 )$\\times 10^{-19}$ s has been estimated correspondin...

  2. Pairing-induced speedup of nuclear spontaneous fission

    E-Print Network [OSTI]

    Jhilam Sadhukhan; J. Dobaczewski; W. Nazarewicz; J. A. Sheikh; A. Baran

    2014-10-06T23:59:59.000Z

    Collective inertia is strongly influenced at the level crossing at which quantum system changes diabatically its microscopic configuration. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of those configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of $^{264}$Fm and $^{240}$Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM$^*$ and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action principle in a four-dimensional collective space of shape and pairing coordinates. Pairing correlations are enhanced along the minimum-action fission path. For the symmetric fission of $^{264}$Fm, where the effect of triaxiality on the fission barrier is large, the geometry of fission pathway in the space of shape degrees of freedom is weakly impacted by pairing. This is not the case for $^{240}$Pu where pairing fluctuations restore the axial symmetry of the dynamic fission trajectory. The minimum-action fission path is strongly impacted by nucleonic pairing. In some cases, the dynamical coupling between shape and pairing degrees of freedom can lead to a dramatic departure from the static picture. Consequently, in the dynamical description of nuclear fission, particle-particle correlations should be considered on the same footing as those associated with shape degrees of freedom.

  3. Excitation energy dependence of fission in the mercury region

    E-Print Network [OSTI]

    J. D. McDonnell; W. Nazarewicz; J. A. Sheikh; A. Staszczak; M. Warda

    2014-06-26T23:59:59.000Z

    Background: Recent experiments on beta-delayed fission reported an asymmetric mass yield in the neutron-deficient nucleus 180Hg. Earlier experiments in the mass region A=190-200 close to the beta-stability line, using the (p,f) and (\\alpha,f) reactions, observed a more symmetric distribution of fission fragments. While the beta-delayed fission of 180Hg can be associated with relatively low excitation energy, this is not the case for light-ion reactions, which result in warm compound nuclei. Purpose: To elucidate the roles of proton and neutron numbers and excitation energy in determining symmetric and asymmetric fission yields, we compute and analyze the isentropic potential energy surfaces of 174,180,198Hg and 196,210Po. Methods: We use the finite-temperature superfluid nuclear density functional theory, for excitation energies up to E*=30MeV and zero angular momentum. For our theoretical framework, we consider the Skyrme energy density functional SkM* and a density-dependent pairing interaction. Results: For 174,180Hg, we predict fission pathways consistent with asymmetric fission at low excitation energies, with the symmetric fission pathway opening very gradually as excitation energy is increased. For 198Hg and 196Po, we expect the nearly-symmetric fission channel to dominate. 210Po shows a preference for a slightly asymmetric pathway at low energies, and a preference for a symmetric pathway at high energies. Conclusions: Our self-consistent theory suggests that excitation energy weakly affects the fission pattern of the nuclei considered. The transition from the asymmetric fission in the proton-rich nuclei to a more symmetric fission in the heavier isotopes is governed by the shell structure of pre-scission configurations.

  4. Nuclear multifragmentation and fission: similarity and differences

    E-Print Network [OSTI]

    V. Karnaukhov; H. Oeschler; S. Avdeyev; V. Rodionov; V. Kirakosyan; A. Simonenko; P. Rukoyatkin; A. Budzanowski; W. Karcz; I. Skwirczynska; B. Czech; L. Chulkov; E. Kuzmin; E. Norbeck; A. Botvina

    2006-02-10T23:59:59.000Z

    Thermal multifragmentation of hot nuclei is interpreted as the nuclear liquid--fog phase transition deep inside the spinodal region. The experimental data for p(8.1GeV) + Au collisions are analyzed. It is concluded that the decay process of hot nuclei is characterized by two size parameters: transition state and freeze-out volumes. The similarity between dynamics of fragmentation and ordinary fission is discussed. The IMF emission time is related to the mean rupture time at the multi-scission point, which corresponds to the kinetic freeze-out configuration.

  5. Fission energy program of the US Department of Energy, FY 1981

    SciTech Connect (OSTI)

    Ferguson, Robert L.

    1980-03-01T23:59:59.000Z

    Information is presented concerning the National Energy Plan and fission energy policy; fission energy program management; converter reactor systems; breeder reactor systems; and special nuclear evaluations and systems.

  6. Nuclear Thermal Rockets: The Physics of the Fission Reactor

    E-Print Network [OSTI]

    Ross, Shane

    Nuclear Thermal Rockets: The Physics of the Fission Reactor Shane D. Ross Control and Dynamical combustion are those powered by nuclear fission. Comparison of Chemical and Nuclear Rockets. Most existent.g., hydrogen and oxygen). In a nuclear rocket, or more precisely, a nuclear thermal rocket, the propellant

  7. PASSAGE OF FISSION PRODUCTS THROUGH THE SKIN OF TUNA

    E-Print Network [OSTI]

    was slow. PASSAGE OF FISSION PRODUCTS THROUGH THE SKIN OF TUNA In relation to "fallout" from nuclear -bomb tests, it is of interest to measure the amounts of radioactive isotopes known to be present in mixtures of fission products which would pass through the skin of fish held under refrigera- tion on fishing vessels

  8. Electron-capture delayed fission properties of [sup 228]Np

    SciTech Connect (OSTI)

    Kreek, S.A.; Hall, H.L.; Gregorich, K.E.; Henderson, R.A.; Leyba, J.D.; Czerwinski, K.R.; Kadkhodayan, B.; Neu, M.P.; Kacher, C.D.; Hamilton, T.M.; Lane, M.R.; Sylwester, E.R.; Tuerler, A.; Lee, D.M.; Nurmia, M.J.; Hoffman, D.C. (Chemistry Department, University of California, Berkeley, California 94720 (United States) Nuclear Science Division, Lawrence Berkeley Laboratory, MS-70A/3307 Berkeley, California 94720 (United States))

    1994-11-01T23:59:59.000Z

    Electron-capture delayed fission was positively identified for the first time in [sup 228]Np produced via the [sup 233]U(50-MeV [ital p],6[ital n])[sup 228]Np reaction. The half-life of the observed fission activity was measured to be 61.4[plus minus]1.4 s. The ECDF mode was verified by an x-ray--fission coincidence experiment. Only about 25% of the expected x-ray--fission coincidences were detected which indicates that [sup 228]U does not have a fission isomer populated by the electron-capture and that the overall lifetime of the high-energy states populated by the electron-capture is less than about 10[sup [minus]17] s. The fission activity was assigned to ECDF of [sup 228]Np based on chemical separation and observation of known progeny activities. The ratio of electron-capture to alpha decay is 1.5[plus minus]0.4 for [sup 228]Np. The production cross section for [sup 228]Np is 35[plus minus]10 [mu]b and the delayed fission probability is (2.0[plus minus]0.9)[times]10[sup [minus]4]. The kinetic energies of coincident fission fragments were measured and a pre-neutron emission, most probable total kinetic energy, of 169[plus minus]6 MeV was obtained. The mass-yield distribution was found to be predominantly asymmetric.

  9. Fission matrix capability for MCNP, Part II - Applications

    SciTech Connect (OSTI)

    Carney, S. E. [University of Michigan, NERS Department, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Brown, F. B. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States); Kiedrowski, B. C. [University of Michigan, NERS Department, 2355 Bonisteel Boulevard, Ann Arbor, MI 48109 (United States); Martin, W. R. [Los Alamos National Laboratory, Monte Carlo Codes Group, MS A143, PO Box 1663, Los Alamos, NM 87545 (United States)

    2013-07-01T23:59:59.000Z

    This paper describes the initial experience and results from implementing a fission matrix capability into the MCNP Monte Carlo code. The fission matrix is obtained at essentially no cost during the normal simulation for criticality calculations. It can be used to provide estimates of the fundamental mode power distribution, the reactor dominance ratio, the eigenvalue spectrum, and higher mode spatial eigenfunctions. It can also be used to accelerate the convergence of the power method iterations. Past difficulties and limitations of the fission matrix approach are overcome with a new sparse representation of the matrix, permitting much larger and more accurate fission matrix representations. Numerous examples are presented. A companion paper (Part I - Theory) describes the theoretical basis for the fission matrix method. (authors)

  10. Improved Fission Neutron Data Base for Active Interrogation of Actinides

    SciTech Connect (OSTI)

    Pozzi, Sara; Czirr, J. Bart; Haight, Robert; Kovash, Michael; Tsvetkov, Pavel

    2013-11-06T23:59:59.000Z

    This project will develop an innovative neutron detection system for active interrogation measurements. Many active interrogation methods to detect fissionable material are based on the detection of neutrons from fission induced by fast neutrons or high-energy gamma rays. The energy spectrum of the fission neutrons provides data to identify the fissionable isotopes and materials such as shielding between the fissionable material and the detector. The proposed path for the project is as follows. First, the team will develop new neutron detection systems and algorithms by Monte Carlo simulations and bench-top experiments. Next, They will characterize and calibrate detection systems both with monoenergetic and white neutron sources. Finally, high-fidelity measurements of neutron emission from fissions induced by fast neutrons will be performed. Several existing fission chambers containing U-235, Pu-239, U-238, or Th-232 will be used to measure the neutron-induced fission neutron emission spectra. The challenge for making confident measurements is the detection of neutrons in the energy ranges of 0.01 – 1 MeV and above 8 MeV, regions where the basic data on the neutron energy spectrum emitted from fission is least well known. In addition, improvements in the specificity of neutron detectors are required throughout the complete energy range: they must be able to clearly distinguish neutrons from other radiations, in particular gamma rays and cosmic rays. The team believes that all of these challenges can be addressed successfully with emerging technologies under development by this collaboration. In particular, the collaboration will address the area of fission neutron emission spectra for isotopes of interest in the advanced fuel cycle initiative (AFCI).

  11. Energy Tracking Software Platform

    SciTech Connect (OSTI)

    Ryan Davis; Nathan Bird; Rebecca Birx; Hal Knowles

    2011-04-04T23:59:59.000Z

    Acceleration has created an interactive energy tracking and visualization platform that supports decreasing electric, water, and gas usage. Homeowners have access to tools that allow them to gauge their use and track progress toward a smaller energy footprint. Real estate agents have access to consumption data, allowing for sharing a comparison with potential home buyers. Home builders have the opportunity to compare their neighborhood's energy efficiency with competitors. Home energy raters have a tool for gauging the progress of their clients after efficiency changes. And, social groups are able to help encourage members to reduce their energy bills and help their environment. EnergyIT.com is the business umbrella for all energy tracking solutions and is designed to provide information about our energy tracking software and promote sales. CompareAndConserve.com (Gainesville-Green.com) helps homeowners conserve energy through education and competition. ToolsForTenants.com helps renters factor energy usage into their housing decisions.

  12. Track 10: Feedback and Improvement

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 10: Feedback and Improvement

  13. MATERIAL TRACKING USING LANMAS

    SciTech Connect (OSTI)

    Armstrong, F.

    2010-06-07T23:59:59.000Z

    LANMAS is a transaction-based nuclear material accountability software product developed to replace outdated and legacy accountability systems throughout the DOE. The core underlying purpose of LANMAS is to track nuclear materials inventory and report transactions (movement, mixing, splitting, decay, etc.) to the Nuclear Materials Management and Safeguards System (NMMSS). While LANMAS performs those functions well, there are many additional functions provided by the software product. As a material is received onto a site or created at a site, its entire lifecycle can be tracked in LANMAS complete to its termination of safeguards. There are separate functions to track material movements between and within material balance areas (MBAs). The level of detail for movements within a MBA is configurable by each site and can be as high as a site designation or as detailed as building/room/rack/row/position. Functionality exists to track the processing of materials, either as individual items or by modeling a bulk process as an individual item to track inputs and outputs from the process. In cases where sites have specialized needs, the system is designed to be flexible so that site specific functionality can be integrated into the product. This paper will demonstrate how the software can be used to input material into an account and track it to its termination of safeguards.

  14. ATLAS Tracking Event Data Model

    E-Print Network [OSTI]

    Åkesson, P F; Costa, M J; Elsing, M; Fleischmann, S; Gaponenko, A N; Liebig, W; Moyse, E; Salzburger, A; Siebel, M

    2006-01-01T23:59:59.000Z

    In this report the event data model (EDM) relevant for tracking in the ATLAS experiment is presented. The core component of the tracking EDM is a common track object which is suited to describe tracks in the innermost tracking sub-detectors and in the muon detectors in offline as well as online reconstruction. The design of the EDM was driven by a demand for modularity and extensibility while taking into account the different requirements of the clients. The structure of the track object and the representation of the tracking-relevant information are described in detail.

  15. Prescission neutron multiplicity and fission probability from Langevin dynamics of nuclear fission

    E-Print Network [OSTI]

    Gargi Chaudhuri; Santanu Pal

    2002-04-01T23:59:59.000Z

    A theoretical model of one-body nuclear friction which was developed earlier, namely the chaos-weighted wall formula, is applied to a dynamical description of compound nuclear decay in the framework of the Langevin equation coupled with statistical evaporation of light particles and photons. We have used both the usual wall formula friction and its chaos-weighted version in the Langevin equation to calculate the fission probability and prescission neutron multiplicity for the compound nuclei $^{178}$W, $^{188}$Pt, $^{200}$Pb, $^{213}$Fr, $^{224}$Th, and $^{251}$Es. We have also obtained the contributions of the presaddle and postsaddle neutrons to the total prescission multiplicity. A detailed analysis of our results leads us to conclude that the chaos-weighted wall formula friction can adequately describe the fission dynamics in the presaddle region. This friction, however, turns out to be too weak to describe the postsaddle dynamics properly. This points to the need for a suitable explanation for the enhanced neutron emission in the postsaddle stage of nuclear fission.

  16. New fission valley for /sup 258/Fm and nuclei beyond

    SciTech Connect (OSTI)

    Moeller, P.; Nix, J.R.; Swiatecki, W.J.

    1986-01-01T23:59:59.000Z

    Experimental results on the fission properties of nuclei close to /sup 264/Fm show sudden and large changes with a change of only one or two neutrons or protons. The nucleus /sup 258/Fm, for instance, undergoes symmetric fission with a half-life of about 0.4 ms and a kinetic energy peaked at about 235 MeV whereas /sup 256/Fm undergoes asymmetric fission with a half-life of about 3 h and a kinetic energy peaked at about 200 MeV. Qualitatively, these sudden changes hve been postulated to be due to the emergence of fragment shells in symmetric fission products close to /sup 132/Sn. A quantitative calculation that shows where high-kinetic-energy symmetric fission occurs and why it is associated with a sudden and large decrease in fission half-lives. The study is based on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. The implications of the new fission valley on the stability of the heaviest elements is discussed. 33 refs., 12 figs.

  17. A New Method of Prompt Fission Neutron Energy Spectrum Unfolding

    SciTech Connect (OSTI)

    Zeynalova, O. V. [Moscow State Institute of Radioengineering, Electronics and Automation, Moscow (Russian Federation); Joint Institute for Nuclear Research, Dubna (Russian Federation); Zeynalov, Sh. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Hambsch, F.-J.; Oberstedt, S. [EC-JRC-Institute for Reference Materials and Measurements, Geel (Belgium)

    2010-11-25T23:59:59.000Z

    The prompt neutron emission in spontaneous fission of {sup 252}Cf has been investigated applying digital signal electronics along with associated digital signal processing algorithms. The goal was to find out the reasons of a long time existing discrepancy between theoretical calculations and the measurements of prompt fission neutron (PFN) emission dependence on the total kinetic energy (TKE) of fission fragments (FF). On the one hand the {sup 252}Cf(sf) reaction is one of the main references for nuclear data, on the other hand the understanding of PFN emission mechanism is very important for nuclear fission theory. Using a twin Frisch-grid ionization chamber for fission fragment (FF) detection and a NE213-equivalent neutron detector in total about 10{sup 7} fission fragment-neutron coincidences have been registered. Fission fragment kinetic energy, mass and angular distribution, neutron time-of-flight and pulse shape have been investigated using a 12 bit waveform digitizer. The signal waveforms have been analyzed using digital signal processing algorithms. For the first time the dependence of the number of emitted neutrons as a function of total kinetic energy (TKE) of the fragments is in very good agreement with theoretical calculations in the range of TKE from 140-220 MeV.

  18. Control system for a small fission reactor

    DOE Patents [OSTI]

    Burelbach, J.P.; Kann, W.J.; Saiveau, J.G.

    1985-02-08T23:59:59.000Z

    A system for controlling the reactivity of a small fission reactor includes an elongated, flexible hollow tube in the general form of a helical coiled spring axially positioned around and outside of the reactor vessel in an annular space between the reactor vessel and a surrounding cylindrical-shaped neutron reflector. A neutron absorbing material is provided within the hollow tube with the rate of the reaction controlled by the extension and compression of the hollow tube, e.g., extension of the tube increases reactivity while its compression reduces reactivity, in varying the amount of neutron absorbing material disposed between the reactor vessel and the neutron reflector. Conventional mechanical displacement means may be employed to control the coil density of the hollow tube as desired.

  19. Detecting fission from special nuclear material sources

    DOE Patents [OSTI]

    Rowland, Mark S. (Alamo, CA); Snyderman, Neal J. (Berkeley, CA)

    2012-06-05T23:59:59.000Z

    A neutron detector system for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. The system includes a graphing component that displays the plot of the neutron distribution from the unknown source over a Poisson distribution and a plot of neutrons due to background or environmental sources. The system further includes a known neutron source placed in proximity to the unknown source to actively interrogate the unknown source in order to accentuate differences in neutron emission from the unknown source from Poisson distributions and/or environmental sources.

  20. Budding and Fission of a multiphase vesicle

    E-Print Network [OSTI]

    Jean-Marc Allain; Martine Ben Amar

    2005-04-08T23:59:59.000Z

    We present a model of bi-phasic vesicle in the limit of large surface tension. In this regime, the vesicle is completely stretched and well described by two spherical caps with a fold which concentrates the membrane stress. The conservation laws and geometric constraints restrict the space of possible shapes to a pair of solutions labeled by a parameter $\\tau$ given by {\\it line tension/pressure}. For a given $\\tau$ value, the two solutions differ by the length of the interface between domains. For a critical value $\\tau\\_c$, the two vesicle shapes become identical and no solution exists above this critical value. This model sheds new light on two proposed mechanisms (osmotic shocks and molecule absorption) to explain the budding and the fission in recent experiments.

  1. Nondestructive fission gas release measurement and analysis

    SciTech Connect (OSTI)

    O'Leary, P.M.; Packard, D.R. (Siemens Nuclear Power Corp., Richland, WA (United States))

    1993-01-01T23:59:59.000Z

    Siemens Power Corporation (SPC) has performed reactor poolside gamma scanning measurements of fuel rods for fission gas release (FGR) detection for more than 10 yr. The measurement system has been previously described. Over the years, the data acquisition system, the method of spectrum analysis, and the means of reducing spectrum interference have been significantly improved. A personal computer (PC)-based multichannel analyzer (MCA) package is used to collect, display, and store high-resolution gamma-ray spectra measured in the fuel rod plenum. A PC spread sheet is used to fit the measured spectra and compute sample count rates after Compton background subtraction. A Zircaloy plenum spacer is often used to reduce positron annihilation interference that can arise from the INCONEL[sup [reg sign

  2. Event-by-event study of neutron observables in spontaneous and thermal fission

    E-Print Network [OSTI]

    R. Vogt; J. Randrup

    2011-09-17T23:59:59.000Z

    The event-by-event fission model FREYA is extended to spontaneous fission of actinides and a variety of neutron observables are studied for spontaneous fission and fission induced by thermal neutrons with a view towards possible applications for detection of special nuclear materials.

  3. PHYSICAL REVIEW VOLUME 183; NUMBER 4 20 J ULY 1969 Single-Particle Theory of Fission*

    E-Print Network [OSTI]

    manuscript received 6 December 1968) The single-particle aspects of nuclear fission theories are investigated

  4. Semiclassical Interpretation of the Mass Asymmetry in Nuclear Fission

    E-Print Network [OSTI]

    M. Brack; S. M. Reimann; M. Sieber

    1997-05-15T23:59:59.000Z

    We give a semiclassical interpretation of the mass asymmetry in the fission of heavy nuclei. Using only a few classical periodic orbits and a cavity model for the nuclear mean field, we reproduce the onset of left-right asymmetric shapes at the fission isomer minimum and the correct topology of the deformation energy surface in the region of the outer fission barrier. We point at the correspondence of the single-particle quantum states responsible for the asymmetry with the leading classical orbits, both lying in similar equatorial planes perpendicular to the symmetry axis of the system.

  5. Experimental Progress Report--Modernizing the Fission Basis

    SciTech Connect (OSTI)

    Macri, R A

    2012-02-17T23:59:59.000Z

    In 2010 a proposal (Modernizing the Fission Basis) was prepared to 'resolve long standing differences between LANL and LLNL associated with the correct fission basis for analysis of nuclear test data'. Collaboration between LANL/LLNL/TUNL has been formed to implement this program by performing high precision measurements of neutron induced fission product yields as a function of incident neutron energy. This new program benefits from successful previous efforts utilizing mono-energetic neutrons undertaken by this collaboration. The first preliminary experiment in this new program was performed between July 24-31, 2011 at TUNL and had 2 main objectives: (1) demonstrating the capability to measure characteristic {gamma}-rays from specific fission products; (2) studying background effects from room scattered neutrons. In addition, a new dual fission ionization chamber has been designed and manufactured. The production design of the chamber is shown in the picture below. The first feasibility experiment to test this chamber is scheduled at the TUNL Tandem Laboratory from September 19-25, 2011. The dual fission chamber design will allow simultaneous exposure of absolute fission fragment emission rate detectors and the thick fission activation foils, positioned between the two chambers. This document formalizes the earlier experimental report demonstrating the experimental capability to make accurate (< 2 %) precision gamma-ray spectroscopic measurements of the excitation function of high fission product yields of the 239Pu(n,f) reaction (induced by quasimonoenergetic neutrons). A second experiment (9/2011) introduced an compact double-sided fission chamber into the experimental arrangement, and so the relative number of incident neutrons striking the sample foil at each bombarding energy is limited only by statistics. (The number of incident neutrons often limits the experimental accuracy.) Fission chamber operation was so exceptional that 2 more chambers have been fabricated; thus fission foils of different isotopes may be left in place with sample changes. The scope of the measurements is both greatly expanded and the results become vetted. Experiment 2 is not reported here. A continuing experiment has been proposed for February 2012.

  6. Sensitivity analysis of the fission gas behavior model in BISON.

    SciTech Connect (OSTI)

    Swiler, Laura Painton; Pastore, Giovanni [Idaho National Laboratory, Idaho Fall, ID; Perez, Danielle [Idaho National Laboratory, Idaho Fall, ID; Williamson, Richard [Idaho National Laboratory, Idaho Fall, ID

    2013-05-01T23:59:59.000Z

    This report summarizes the result of a NEAMS project focused on sensitivity analysis of a new model for the fission gas behavior (release and swelling) in the BISON fuel performance code of Idaho National Laboratory. Using the new model in BISON, the sensitivity of the calculated fission gas release and swelling to the involved parameters and the associated uncertainties is investigated. The study results in a quantitative assessment of the role of intrinsic uncertainties in the analysis of fission gas behavior in nuclear fuel.

  7. Distribution of fission products in an LMFBR: summary

    SciTech Connect (OSTI)

    Villarreal, R.; Young, J.O.

    1985-01-01T23:59:59.000Z

    The overall distribution of fission products released from experimental subassemblies containing breached fuel elements has been determined in the fuel and throughout the EBR-II primary and secondary reactor systems. Identification of the fission products released to the primary sodium and location of areas of concentration was important in anticipating radioactive species and levels of deposited fission and activation products on components removed from the primary tank for maintenance and repair. The results of extensive radioanalytical measurements on the fuel, fuel cladding, primary sodium and cover gas system, secondary sodium and cover gas system and steam system are summarized.

  8. Active Fusion and Fission Processes on a Fluid Membrane

    E-Print Network [OSTI]

    Madan Rao; Sarasij R C

    2001-02-26T23:59:59.000Z

    We investigate the steady states and dynamical instabilities resulting from ``particles'' depositing on (fusion) and pinching off (fission) a fluid membrane. These particles could be either small lipid vesicles or isolated proteins. In the stable case, such fusion/fission events suppress long wavelength fluctuations of the membrane. In the unstable case, the membrane shoots out long tubular structures reminiscent of endosomal compartments or folded structures as in internal membranes like the endoplasmic reticulum or Golgi. We argue that these fusion/fission events should be strongly affected by tension.

  9. Measurements of actinide-fission product yields in Caliban and Prospero metallic core reactor fission neutron fields

    SciTech Connect (OSTI)

    Casoli, P.; Authier, N. [CEA, Centre de Valduc, 21120 Is-sur-Tille (France); Laurec, J.; Bauge, E.; Granier, T. [CEA, Centre DIF, 91297 Arpajon (France)

    2011-07-01T23:59:59.000Z

    In the 1970's and early 1980's, an experimental program was performed on the facilities of the CEA Valduc Research Center to measure several actinide-fission product yields. Experiments were, in particular, completed on the Caliban and Prospero metallic core reactors to study fission-neutron-induced reactions on {sup 233}U, {sup 235}U, and {sup 239}Pu. Thick actinide samples were irradiated and the number of nuclei of each fission product was determined by gamma spectrometry. Fission chambers were irradiated simultaneously to measure the numbers of fissions in thin deposits of the same actinides. The masses of the thick samples and the thin deposits were determined by mass spectrometry and alpha spectrometry. The results of these experiments will be fully presented in this paper for the first time. A description of the Caliban and Prospero reactors, their characteristics and performances, and explanations about the experimental approach will also be given in the article. A recent work has been completed to analyze and reinterpret these measurements and particularly to evaluate the associated uncertainties. In this context, calculations have also been carried out with the Monte Carlo transport code Tripoli-4, using the published benchmarked Caliban description and a three-dimensional model of Prospero, to determine the average neutron energy causing fission. Simulation results will be discussed in this paper. Finally, new fission yield measurements will be proposed on Caliban and Prospero reactors to strengthen the results of the first experiments. (authors)

  10. Pairing-induced speedup of nuclear spontaneous fission

    E-Print Network [OSTI]

    Sadhukhan, Jhilam; Nazarewicz, W; Sheikh, J A; Baran, A

    2014-01-01T23:59:59.000Z

    Collective inertia is strongly influenced at the level crossing at which quantum system changes diabatically its microscopic configuration. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of those configuration changes. Competition between pairing and level crossing is thus expected to have a profound impact on spontaneous fission lifetimes. To elucidate the role of nucleonic pairing on spontaneous fission, we study the dynamic fission trajectories of $^{264}$Fm and $^{240}$Pu using the state-of-the-art self-consistent framework. We employ the superfluid nuclear density functional theory with the Skyrme energy density functional SkM$^*$ and a density-dependent pairing interaction. Along with shape variables, proton and neutron pairing correlations are taken as collective coordinates. The collective inertia tensor is calculated within the nonperturbative cranking approximation. The fission paths are obtained by using the least action princip...

  11. Nuclear Graphite -Fission Reactor Brief Outline of Experience and

    E-Print Network [OSTI]

    McDonald, Kirk

    Nuclear Graphite - Fission Reactor Brief Outline of Experience and Understanding Professor Barry J · Physical Changes ­ to Polycrystalline Graphite due to Fast Neutron Damage and Radiolytic Oxidation ­ Provided channels for control rods and coolant gas · Neutron Shield ­ Boronated graphite · Thermal columns

  12. actinides fission products: Topics by E-print Network

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

    the use of uranium targets is shown to be advantageous to other materials, such as thorium. Therefore, in order to produce fissions in U-238 and reduce the plutonium inventory,...

  13. Singlet exciton fission : applications to solar energy harvesting

    E-Print Network [OSTI]

    Thompson, Nicholas John

    2014-01-01T23:59:59.000Z

    Singlet exciton fission transforms a single molecular excited state into two excited states of half the energy. When used in solar cells it can double the photocurrent from high energy photons increasing the maximum ...

  14. Fission Cross Section Measurements of Actinides at LANSCE

    SciTech Connect (OSTI)

    F. Tovesson; A. B. Laptev; T. S. Hill

    2011-08-01T23:59:59.000Z

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the 235U standard. Recent measurements include the 233, 238U, 239-242Pu, and 243Am neutron-induced fission cross sections. In this paper preliminary results for fission cross sections of 243Am and 233U will be presented.

  15. Fusion-fission reactions with modified Woods-Saxon potential

    E-Print Network [OSTI]

    Ning Wang; Kai Zhao; Werner Scheid; Xizhen Wu

    2007-12-15T23:59:59.000Z

    A modified Woods-Saxon potential model is proposed for a unified description of the entrance channel fusion barrier and the fission barrier of fusion-fission reactions based on the Skyrme energy-density functional approach. The fusion excitation functions of 120 reactions have been systematically studied. The fusion (capture) cross sections are well described with the calculated potential and an empirical barrier distribution. Incorporating a statistical model (HIVAP code) for describing the decay of the compound nucleus, the evaporation residue (and fission) cross sections of 51 fusion-fission reactions have been systematically investigated. Optimal values of some key parameters of the HIVAP code are obtained based on the experimental data of these reactions. The experimental data are reasonably well reproduced by the calculated results. The upper and lower confidence limits of the systematic errors of the calculated results are given.

  16. Spontaneous fission half-lives for ground state nuclides

    SciTech Connect (OSTI)

    Holden, N.E. (Brookhaven National Lab., Upton, NY (United States)); Hoffman, D.C. (Lawrence Berkeley Lab., CA (United States))

    1991-01-01T23:59:59.000Z

    Measurements of the spontaneous fission half-lives of nuclides of elements Z = 90 to 107 have been compiled and evaluated. Recommended values are presented. 126 refs., 96 tabs.

  17. A summary of EPRI's fusion-fission hybrid evaluation activities

    SciTech Connect (OSTI)

    Amherd, N.A.

    1982-10-01T23:59:59.000Z

    A summary is given of recently completed and planned fusion-fission hybrid projects. Electricty supply/demand projections and estimates of future uranium requirements for several different combinations of nuclear systems, including hybrids, are discussed.

  18. March 2014 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    Fission And Nuclear Technologies Science Subject Feed Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 72 > Peer-review study of the draft handbook...

  19. June 2014 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    Viewed Documents for Fission And Nuclear Technologies Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 78 Estimation of gas leak rates through very...

  20. April 2013 Most Viewed Documents for Fission And Nuclear Technologies...

    Office of Scientific and Technical Information (OSTI)

    Fission And Nuclear Technologies Science Subject Feed Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (null) 298 > Estimation of gas leak rates through very...

  1. Total Prompt Energy Release in the Neutron-Induced Fission

    E-Print Network [OSTI]

    D. G. Madland

    2006-01-01T23:59:59.000Z

    This study addresses, for the first time, the total prompt energy release and its components for the fission of 235 U, 238 U, and 239 Pu as a function of the kinetic energy of the neutron inducing the fission. The components are extracted from experimental measurements, where they exist, together with model-dependent calculation, interpolation, and extrapolation. While the components display clear dependencies upon the incident neutron energy, their sums display only weak, yet definite, energy dependencies. Also addressed is the total prompt energy deposition in fission for the same three systems. Results are presented in equation form. New measurements are recommended as a consequence of this study. Key words: Energy release and energy deposition in neutron-induced fission,

  2. The Nature of Singlet Exciton Fission in Carotenoid Aggregates

    E-Print Network [OSTI]

    Musser, Andrew J.; Maiuri, Margherita; Brida, Daniele; Cerullo, Giulio; Friend, Richard H.; Clark, Jenny

    2015-03-31T23:59:59.000Z

    Singlet exciton fission allows the fast and efficient generation of two spin triplet states from one photoexcited singlet. It has the potential to improve organic photovoltaics, enabling efficient coupling to the blue to ultraviolet region...

  3. Identification of Fissionable Materials Using the Tagged Neutron Technique

    SciTech Connect (OSTI)

    R.P. Keegan, J.P. Hurley, J.R. Tinsley, R. Trainham

    2009-06-30T23:59:59.000Z

    This summary describes experiments to detect and identify fissionable materials using the tagged neutron technique. The objective of this work is to enhance homeland security capability to find fissionable material that may be smuggled inside shipping boxes, containers, or vehicles. The technique distinguishes depleted uranium from lead, steel, and tungsten. Future work involves optimizing the technique to increase the count rate by many orders of magnitude and to build in the additional capability to image hidden fissionable materials. The tagged neutron approach is very different to other techniques based on neutron die-away or photo-fission. This work builds on the development of the Associated Particle Imaging (API) technique at the Special Technologies Laboratory (STL) [1]. Similar investigations have been performed by teams at the Oak Ridge National Laboratory (ORNL), the Khlopin Radium Institute in Russia, and by the EURITRACK collaboration in the European Union [2,3,4].

  4. Delayed neutron measurements from fast fission of actinide waste isotopes

    E-Print Network [OSTI]

    Charlton, William S.

    1997-01-01T23:59:59.000Z

    A study was performed to determine the delayed neutron emission properties from fast fission of several actinide waste isotopes. The specific isotopes evaluated were U-235, Np-237, and Am-243. A calculational technique based on the microscopic...

  5. Automated micro-tracking planar solar concentrators

    E-Print Network [OSTI]

    Hallas, Justin Matthew

    2011-01-01T23:59:59.000Z

    E. Ford, “Reactive self-tracking solar concentration: designFord, “Reactive self- tracking solar concentration: designAutomated Micro-Tracking Planar Solar Concentrators by

  6. Pollution Prevention Tracking and Reporting System | Department...

    Energy Savers [EERE]

    Pollution Prevention Tracking and Reporting System Pollution Prevention Tracking and Reporting System Welcome to the Department of Energy's Pollution Prevention Tracking and...

  7. Description of true and delayed ternary nuclear fission accompanied by the emission of various third particles

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@vsu.ru; Kadmensky, S. S.; Lyubashevsky, D. E. [Voronezh State University (Russian Federation)

    2010-08-15T23:59:59.000Z

    The mechanisms and the features of the main types of nuclear ternary fission (that is, true ternary fission, in which a third particle is emitted before the rupture of the fissioning nucleus into fragments, and delayed ternary fission, in which a third particle is emitted from fission fragments going apart) are investigated within quantum-mechanical fission theory. The features of T-odd asymmetry in true ternary nuclear fission induced by cold polarized neutrons are investigated for the cases where alpha particles, prescission neutrons, and photons appear as third particles emitted by fissioning nuclei, the Coriolis interaction of the spin of the polarized fissioning nucleus with the spin of the third particle and the interference between the fission amplitudes for neutron resonances excited in the fissioning nucleus in the case of projectile-neutron capture being taken into account. For the cases where third particles emitted by fission fragments are evaporated neutrons or photons, T-odd asymmetries in delayed ternary nuclear fission induced by cold polarized neutrons are analyzed with allowance for the mechanism of pumping of large fission-fragment spins oriented orthogonally to the fragment-emission direction and with allowance for the interference between the fission amplitudes for neutron resonances.

  8. Fission and Nuclear Liquid-Gas Phase Transition

    E-Print Network [OSTI]

    E. A. Cherepanov; V. A. Karnaukhov

    2007-03-30T23:59:59.000Z

    The temperature dependence of the liquid-drop fission barrier is considered, the critical temperature for the liquid-gas phase transition in nuclear matter being a parameter. Experimental and calculated data on the fission probability are compared for highly excited $^{188}$Os. The calculations have been made in the framework of the statistical model. It is concluded that the critical temperature for the nuclear liquid--gas phase transition is higher than 16 MeV.

  9. Further search for high-energy neutrons in fission

    SciTech Connect (OSTI)

    Popov, A.B.; Rudenko, V.T.; Samosvat, G.S.

    1980-08-01T23:59:59.000Z

    A sample of /sup 209/Bi was irradiated in a reactor and products of the (n, xn) reaction were detected by means of a Ge-Li detector. It is shown that the fission neutron spectrum follows approximately a Maxwellian distribution for energies up to at least 30 MeV, while in the range 40--60 MeV the neutron yield is no more than about 4x10/sup -10/ per fission event.

  10. Present Status of Fission Research Based on TDDFT

    E-Print Network [OSTI]

    Yoritaka Iwata

    2015-01-28T23:59:59.000Z

    Fission resulting from collision of atomic nuclei is systematically investigated based on time-dependent density functional calculations. Time-dependent density functional theory (TDDFT) is a framework, which enables us to treat quantum many-body dynamics with nucleon degrees of freedom. In this article a theoretical framework called Composite-Nucleus Constrained TDDFT is introduced, and charge equilibrium hypothesis for collision fission dynamics is examined.

  11. Evaluation and compilation of fission product yields 1993

    SciTech Connect (OSTI)

    England, T.R.; Rider, B.F.

    1995-12-31T23:59:59.000Z

    This document is the latest in a series of compilations of fission yield data. Fission yield measurements reported in the open literature and calculated charge distributions have been used to produce a recommended set of yields for the fission products. The original data with reference sources, and the recommended yields axe presented in tabular form. These include many nuclides which fission by neutrons at several energies. These energies include thermal energies (T), fission spectrum energies (F), 14 meV High Energy (H or HE), and spontaneous fission (S), in six sets of ten each. Set A includes U235T, U235F, U235HE, U238F, U238HE, Pu239T, Pu239F, Pu241T, U233T, Th232F. Set B includes U233F, U233HE, U236F, Pu239H, Pu240F, Pu241F, Pu242F, Th232H, Np237F, Cf252S. Set C includes U234F, U237F, Pu240H, U234HE, U236HE, Pu238F, Am241F, Am243F, Np238F, Cm242F. Set D includes Th227T, Th229T, Pa231F, Am241T, Am241H, Am242MT, Cm245T, Cf249T, Cf251T, Es254T. Set E includes Cf250S, Cm244S, Cm248S, Es253S, Fm254S, Fm255T, Fm256S, Np237H, U232T, U238S. Set F includes Cm243T, Cm246S, Cm243F, Cm244F, Cm246F, Cm248F, Pu242H, Np237T, Pu240T, and Pu242T to complete fission product yield evaluations for 60 fissioning systems in all. This report also serves as the primary documentation for the second evaluation of yields in ENDF/B-VI released in 1993.

  12. Electron-capture delayed fission properties of {sup 242}Es

    SciTech Connect (OSTI)

    Shaughnessy, D. A. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Chemistry Department, University of California, Berkeley, California 94720 (United States); Adams, J. L. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Gregorich, K. E. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Lane, M. R. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Laue, C. A. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Lee, D. M. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); McGrath, C. A. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Patin, J. B. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Strellis, D. A. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Sylwester, E. R. [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States) [Nuclear Science Division, Lawrence Berkeley National Laboratory, MS 70-319, Berkeley, California 94720 (United States); Chemistry Department, University of California, Berkeley, California 94720 (United States)] (and others)

    2000-04-01T23:59:59.000Z

    Electron-capture delayed fission of {sup 242}Es produced via the {sup 233}U({sup 14}N,5n){sup 242}Es reaction at 87 MeV (on target) was observed to decay with a half-life of 11{+-}3 s, consistent with the reported {alpha}-decay half-life of {sup 242}Es of 16{sub -4}{sup +6} s. The mass-yield distribution of the fission fragments is highly asymmetric. The average pre-neutron emission total kinetic energy of the fragments was measured to be 183{+-}18 MeV. Based on the ratio of the measured number of fission events to the measured number of {alpha} decays from the electron-capture daughter {sup 242}Cf (100% {alpha} branch), the probability of delayed fission was determined to be 0.006{+-}0.002. This value for the delayed fission probability fits the experimental trend of increasing delayed fission probability with increasing Q value for electron capture. (c) 2000 The American Physical Society.

  13. Early Flight Fission Test Facilities (EFF-TF) To Support Near-Term Space Fission Systems

    SciTech Connect (OSTI)

    Van Dyke, Melissa [Marshall Space Flight Center, National Aeronautics and Space Administration, Huntsville, Alabama, 35812 (United States)

    2004-02-04T23:59:59.000Z

    Through hardware based design and testing, the EFF-TF investigates fission power and propulsion component, subsystems, and integrated system design and performance. Through demonstration of systems concepts (designed by Sandia and Los Alamos National Laboratories) in relevant environments, previous non-nuclear tests in the EFF-TF have proven to be a highly effective method (from both cost and performance standpoint) to identify and resolve integration issues. Ongoing research at the EFF-TF is geared towards facilitating research, development, system integration, and system utilization via cooperative efforts with DOE labs, industry, universities, and other NASA centers. This paper describes the current efforts for 2003.

  14. TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

    E-Print Network [OSTI]

    Powers, Jeffrey

    2011-01-01T23:59:59.000Z

    generation [1, 5, 6, 7]. Nuclear fission energy systems thatgeneration from nuclear fission plants may in fact need toof a Hybrid Fusion-Fission Nuclear Energy System. ” Thesis.

  15. Ring fission of anthracene by a eukaryota

    SciTech Connect (OSTI)

    Hammel, K.E.; Green, B.; Gai, W.Z.

    1993-01-01T23:59:59.000Z

    Ligninolytic fungi are unique among eukaryotes in their ability to degrade polycyclic aromatic hydrocarbons (PAHs), but the mechanism for this process is unknown. Although certain PAHs are oxidized in vitro by the fungal lignin peroxidases (LiPs) that catalyze ligninolysis, it has never been shown that LiPs initiate PAH degradation in vivo. To address these problems, the metabolism of anthracene (AC) and its in vitro oxidation product, 9,10-anthraquinone (AQ), was examined by chromatographic and isotope dilution techniques in Phanerochaete chrysosporium. The fungal oxidation of AC to AQ was rapid, and both AC and AQ were significantly mineralized. Both compounds were cleaved by the fungus to give the same ring-fission metabolite, phthalic acid, and phthalate production from AQ was shown to occur only under ligninolytic culture conditions. These results show that the major pathway for AC degradation in Phanerochaete proceeds AC -> AQ -> phthalate + CO2 and that it is probably mediated by LiPs and other enzymes of ligninolytic metabolism.

  16. Ring fission of anthracene by a eukaryote

    SciTech Connect (OSTI)

    Hammel, K.E.; Green, B.; Wen Zhi Gai (State Univ. of New York, Syracuse (United States))

    1991-12-01T23:59:59.000Z

    Ligninolytic fungi are unique among eukaryotes in their ability to degrade polycyclic aromatic hydrocarbons (PAHs), but the mechanism for this process is unknown. Although certain PAHs are oxidized in vitro by the fungal lignin peroxidases (LiPs) that catalyze ligninolysis, it has never been shown that LiPs initiate PAH degradation in vivo. To address these problems, the metabolism of anthracene (AC) and its in vitro oxidation product, 9,10-anthraquinone (AQ), was examined by chromatographic and isotope dilution techniques in Phanerochaete chrysosporium. The fungal oxidation of AC to AQ was rapid, and both AC and AQ were significantly mineralized. Both compounds were cleaved by the fungus to give the same ring-fission metabolite, phthalic acid, and phthalate production from AQ was shown to occur only under ligninolytic culture conditions. These results show that the major pathway for AC degradation in Phanerochaete proceeds AC {yields} AQ {yields} phthalate + CO{sub 2} and that it is probably mediated by LiPs and other enzymes of ligninolytic metabolism.

  17. Control system for a small fission reactor

    DOE Patents [OSTI]

    Burelbach, James P. (Glen Ellyn, IL); Kann, William J. (Park Ridge, IL); Saiveau, James G. (Hickory Hills, IL)

    1986-01-01T23:59:59.000Z

    A system for controlling the reactivity of a small fission reactor includes an elongated, flexible hollow tube in the general form of a helical coiled spring axially positioned around and outside of the reactor vessel in an annular space between the reactor vessel and a surrounding cylindrical-shaped neutron reflector. A neutron absorbing material is provided within the hollow tube with the rate of the reaction controlled by the extension and compression of the hollow tube, e.g., extension of the tube increases reactivity while its compression reduces reactivity, in varying the amount of neutron absorbing material disposed between the reactor vessel and the neutron reflector. Conventional mechanical displacement means may be employed to control the coil density of the hollow tube as desired. In another embodiment, a plurality of flexible hollow tubes each containing a neutron absorber are positioned adjacent to one another in spaced relation around the periphery of the reactor vessel and inside the outer neutron reflector with reactivity controlled by the extension and compression of all or some of the coiled hollow tubes. Yet another embodiment of the invention envisions the neutron reflector in the form of an expandable coil spring positioned in an annular space between the reactor vessel and an outer neutron absorbing structure for controlling the neutron flux reflected back into the reactor vessel.

  18. Description of Induced Nuclear Fission with Skyrme Energy Functionals: I. Static Potential Energy Surfaces and Fission Fragment Properties

    E-Print Network [OSTI]

    N. Schunck; D. Duke; H. Carr; A. Knoll

    2014-09-17T23:59:59.000Z

    Eighty years after its experimental discovery, a microscopic description of induced nuclear fission based solely on the interactions between neutrons and protons and quantum many-body methods still poses formidable challenges. The goal of this paper is to contribute to the development of a predictive microscopic framework for the accurate calculation of static properties of fission fragments for hot fission and thermal or slow neutrons. To this end, we focus on the 239Pu(n,f) reaction and employ nuclear density functional theory with Skyrme energy densities. Potential energy surfaces are computed at the Hartree-Fock-Bogoliubov approximation with up to five collective variables. We find that the triaxial degree of freedom plays an important role, both near the fission barrier and at scission. The impact of the parameterization of the Skyrme energy density on deformation properties from the ground-state up to scission is also quantified. We introduce a general template for the detailed description of fission fragment properties. It is based on the careful analysis of the scission point, using both advanced topological methods and recently proposed quantum many-body techniques. We conclude that an accurate prediction of fission fragment properties at low incident neutron energies, although technologically demanding, should be within the reach of current nuclear density functional theory.

  19. Effect of transients in nuclear fission on multiplicity of prescission neutrons

    E-Print Network [OSTI]

    Gargi Chaudhuri; Santanu Pal

    2002-04-19T23:59:59.000Z

    Transients in the fission of highly excited nuclei are studied in the framework of the Langevin equation. Time-dependent fission widths are calculated which show that after the initial transients, a steady flow towards the scission point is established not only for nuclei which have fission barriers but also for nuclei which have no fission barrier. It is shown from a comparison of the transient time and the fission life time that fission changes from a diffusive to a transient dominated process over a certain transition region as a function of the spin of the fissioning nucleus. Multiplicities of prescission neutrons are calculated in a statistical model with as well as without a single swoop description of fission and they are found to differ in the transition region. We however find that the difference is marginal and hence a single swoop picture of fission though not strictly valid in the transition region can still be used in the statistical model calculations.

  20. Method to calibrate fission chambers in Campbelling mode

    SciTech Connect (OSTI)

    Geslot, Benoit; Filliatre, Philippe; Jammes, Christian; Di Salvo, Jacques; Breaud, Stephane; Villard, Jean-Francois [CEA, DEN, Cadarache, SPEx, LDCI, F-13108 S Paul Lez Durance, (France); Unruh, Troy C. [INL, Idaho Natl Lab, Idaho Falls, ID 83415 (United States)

    2012-08-15T23:59:59.000Z

    Fission chambers are neutron detectors which are widely used to instrument experimental reactors such as material testing reactors or zero power reactors. In the presence of a high level mixed gamma and neutron flux, fission chambers can be operated in Campbelling mode (also known as 'fluctuation mode' or 'mean square voltage mode') to provide reliable and precise neutron related measurements. Fission chamber calibration in Campbelling mode (in terms of neutron flux) is usually done empirically using a calibrated reference detector. A major drawback of this method is that calibration measurements have to be performed in a neutron environment very similar to the one in which the calibrated detector will be used afterwards. What is proposed here is a different approach based on characterizing the fission chamber response in terms of fission rate. This way, the detector calibration coefficient is independent from the neutron spectrum and can be determined prior to the experiment. The fissile deposit response to the neutron spectrum can then be assessed independently by other means (experimental or numerical). In this paper, the response of CEA-made miniature fission chambers in Campbelling mode is studied. A theoretical model of the signal is used to calculate the calibration coefficient. The model's input parameters come from statistical distribution of individual pulses. Supporting measurements were made in the CEA Cadarache zero power reactor MINERVE and results are compared to an empirical Campbelling mode calibration. The tested fission chamber calibration coefficient is roughly 2*10{sup -26} A{sup 2}/Hz/(c/s). Both numerical and empirical methods give consistent results, however a deviation of about 15% was observed. (authors)

  1. Vertexing and Tracking Software at LHCb

    E-Print Network [OSTI]

    Bowen, Espen Eie

    2015-01-01T23:59:59.000Z

    The LHCb experiment is a dedicated heavy flavour experiment at the LHC. Its primary goal is to search for indirect evidence of New Physics in CP violation and rare decays of beauty and charm hadrons. The detector includes a high granularity silicon-strip vertex detector, a silicon-strip detector upstream of the magnet and three stations of silicon-strip detectors and straw drift tubes downstream of the magnet. The software used to perform the track reconstruction and primary vertex reconstruction is described in detail along with a discussion of its performance.

  2. The Future of Energy from Nuclear Fission

    SciTech Connect (OSTI)

    Kim, Son H.; Taiwo, Temitope

    2013-04-13T23:59:59.000Z

    Nuclear energy is an important part of our current global energy system, and contributes to supplying the significant demand for electricity for many nations around the world. There are 433 commercial nuclear power reactors operating in 30 countries with an installed capacity of 367 GWe as of October 2011 (IAEA PRIS, 2011). Nuclear electricity generation totaled 2630 TWh in 2010 representing 14% the world’s electricity generation. The top five countries of total installed nuclear capacity are the US, France, Japan, Russia and South Korea at 102, 63, 45, 24, and 21 GWe, respectively (WNA, 2012a). The nuclear capacity of these five countries represents more than half, 68%, of the total global nuclear capacity. The role of nuclear power in the global energy system today has been motivated by several factors including the growing demand for electric power, the regional availability of fossil resources and energy security concerns, and the relative competitiveness of nuclear power as a source of base-load electricity. There is additional motivation for the use of nuclear power because it does not produce greenhouse gas (GHG) emissions or local air pollutants during its operation and contributes to low levels of emissions throughout the lifecycle of the nuclear energy system (Beerten, J. et. al., 2009). Energy from nuclear fission primarily in the form of electric power and potentially as a source of industrial heat could play a greater role for meeting the long-term growing demand for energy worldwide while addressing the concern for climate change from rising GHG emissions. However, the nature of nuclear fission as a tremendously compact and dense form of energy production with associated high concentrations of radioactive materials has particular and unique challenges as well as benefits. These challenges include not only the safety and cost of nuclear reactors, but proliferation concerns, safeguard and storage of nuclear materials associated with nuclear fuel cycles. In March of 2011, an unprecedented earthquake of 9 magnitude and ensuing tsunami off the east coast of Japan caused a severe nuclear accident in Fukushima, Japan (Prime Minister of Japan and His Cabinet, 2011). The severity of the nuclear accident in Japan has brought about a reinvestigation of nuclear energy policy and deployment activities for many nations around the world, most notably in Japan and Germany (BBC, 2011; Reuter, 2011). The response to the accident has been mixed and its full impact may not be realized for many years to come. The nuclear accident in Fukushima, Japan has not directly affected the significant on-going nuclear deployment activities in many countries. China, Russia, India, and South Korea, as well as others, are continuing with their deployment plans. As of October 2011, China had the most reactors under construction at 27, while Russia, India, and South Korea had 11, 6, and 5 reactors under construction, respectively (IAEA PRIS, 2011). Ten other nations have one or two reactors currently under construction. Many more reactors are planned for future deployment in China, Russia, and India, as well as in the US. Based on the World Nuclear Association’s data, the realization of China’s deployment plan implies that China will surpass the US in total nuclear capacity some time in the future.

  3. LED Price Tracking Form

    Broader source: Energy.gov [DOE]

    DOE intends to update the SSL Pricing and Efficacy Trend Analysis for Utility Program Planning report on an annual basis, but doing so requires that we have sufficient product and purchase data including acquisition date, purchase price, product category, and rated initial lumens. Those interested in helping collect this data are asked to use the LED Price Tracking FormMicrosoft Excel and follow the instructions for submitting data.

  4. Study of the Fusion-Fission Process in the $^{35}Cl+^{24}Mg$ Reaction

    E-Print Network [OSTI]

    C. Beck; ; Sl. Cavallaro; ; R. Dayras

    1998-04-30T23:59:59.000Z

    Fusion-fission and fully energy-damped binary processes of the $^{35}$Cl+$^{24}$Mg reaction were investigated using particle-particle coincidence techniques at a $^{35}$Cl bombarding energy of E$_{lab}$ $\\approx$ 8 MeV/nucleon. Inclusive data were also taken in order to determine the partial wave distribution of the fusion process. The fragment-fragment correlation data show that the majority of events arises from a binary-decay process with a relatively large multiplicity of secondary light-charged particles emitted by the two primary excited fragments in the exit channel. No evidence is observed for ternary-breakup processes, as expected from the systematics recently established for incident energies below 15 MeV/nucleon and for a large number of reactions. The binary-process results are compared with predictions of statistical-model calculations. The calculations were performed using the Extended Hauser-Feshbach method, based on the available phase space at the scission point of the compound nucleus. This new method uses temperature-dependent level densities and its predictions are in good agreement with the presented experimental data, thus consistent with the fusion-fission origin of the binary fully-damped yields.

  5. Directional measurements for sources of fission neutrons

    SciTech Connect (OSTI)

    Byrd, R.C.; Auchampaugh, G.F.; Feldman, W.C.

    1993-11-01T23:59:59.000Z

    Although penetrating neutron and gamma-ray emissions arguably provide the most effective signals for locating sources of nuclear radiation, their relatively low fluxes make searching for radioactive materials a tedious process. Even assuming lightly shielded sources and detectors with large areas and high efficiencies, estimated counting times can exceed several minutes for source separations greater than ten meters. Because determining the source position requires measurements at several locations, each with its own background, the search procedure can be lengthy and difficult to automate. Although directional measurements can be helpful, conventional collimation reduces count rates and increases the detector size and weight prohibitively, especially for neutron instruments. We describe an alternative approach for locating radiation sources that is based on the concept of a polarized radiation field. In this model, the presence of a source adds a directional component to the randomly oriented background radiation. The net direction of the local field indicates the source angle, and the magnitude provides an estimate of the distance to the source. The search detector is therefore seen as a device that responds to this polarized radiation field. Our proposed instrument simply substitutes segmented detectors for conventional single-element ones, so it requires little or no collimating material or additional weight. Attenuation across the detector creates differences in the count rates for opposite segments, whose ratios can be used to calculate the orthogonal components of the polarization vector. Although this approach is applicable to different types of radiation and detectors, in this report we demonstrate its use for sources of fission neutrons by using a prototype fast-neutron detector, which also provides background-corrected energy spectra for the incident neutrons.

  6. Neutron source capability assessment for cumulative fission yields measurements

    SciTech Connect (OSTI)

    Descalle, M A; Dekin, W; Kenneally, J

    2011-04-06T23:59:59.000Z

    A recent analysis of high-quality cumulative fission yields data for Pu-239 published in the peer-reviewed literature showed that the quoted experimental uncertainties do not allow a clear statement on how the fission yields vary as a function of energy. [Prussin2009] To make such a statement requires a set of experiments with well 'controlled' and understood sources of experimental errors to reduce uncertainties as low as possible, ideally in the 1 to 2% range. The Inter Laboratory Working Group (ILWOG) determined that Directed Stockpile Work (DSW) would benefit from an experimental program with the stated goal to reduce the measurement uncertainties significantly in order to make a definitive statement of the relationship of energy dependence to the cumulative fission yields. Following recent discussions between Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), there is a renewed interest in developing a concerted experimental program to measure fission yields in a neutron energy range from thermal energy (0.025 eV) to 14 MeV with an emphasis on discrete energies from 0.5 to 4 MeV. Ideally, fission yields would be measured at single energies, however, in practice there are only 'quasi-monoenergetic' neutrons sources of finite width. This report outlines a capability assessment as of June 2011 of available neutron sources that could be used as part of a concerted experimental program to measure cumulative fission yields. In a framework of international collaborations, capabilities available in the United States, at the Atomic Weapons Establishment (AWE) in the United Kingdom and at the Commissariat Energie Atomique (CEA) in France are listed. There is a need to develop an experimental program that will reduce the measurement uncertainties significantly in order to make a definitive statement of the relationship of energy dependence to the cumulative fission yields. Fission and monoenergetic neutron sources are available that could support these fission yield experiments in the US, as well as at AWE and CEA. Considerations that will impact the final choice of experimental venues are: (1) Availability during the timeframe of interest; (2) Ability to accommodate special nuclear materials; (3) Cost; (4) Availability of counting facilities; and (5) Expected experimental uncertainties.

  7. Kinetic energy deficit in the symmetric fission of /sup 259/Md. [Light particle emission in /sup 256/Fm fission

    SciTech Connect (OSTI)

    Hulet, E.K.; Wild, J.F.; Lougheed, R.W.; Baisden, P.A.; Dougan, R.J.; Mustafa, M.G.

    1980-10-01T23:59:59.000Z

    The fragment energies of about 725 coincidence events have now been observed in the spontaneous fission (SF) decay of 105-min /sup 259/Md since its discovery in 1977. The fission of /sup 259/Md is characterized by a symmetric mass distribution, similar to those of /sup 258/Fm and /sup 259/Fm, but with a broad total kinetic energy (anti TKE) distribution which peaks at about 195 MeV, in contrast to those of /sup 258/Fm and /sup 259/Fm, for which the anti TKE is about 240 MeV. This kinetic energy deficit, approx. 40 MeV, has been postulated to be due to the emission of hydrogen-like particles by /sup 259/Md at the scission point in a large fraction of the fissions, leaving the residual fissioning nucleus with 100 protons. The residual nucleus would then be able to divide into two ultrastable tin-like fission fragments, but with less kinetic energy than that observed in the SF of /sup 258/Fm and /sup 259/Fm, because of binding-energy losses and a reduction in the Coulomb repulsion of the major fragments. To test this hypothesis, counter-telescope experiments aimed at detecting and identifying these light particles were performed. In 439 SF events 3 + 3 protons of the appropriate energy were observed, too few to account for the kinetic energy deficit in the fission of /sup 259/Md. There seems to be no explanation for this problem within the framework of current fission theory. These results are discussed along with preliminary measurements of light-particle emission in the SF of /sup 256/Fm. 5 figures.

  8. Emergence of Fusion/Fission Cycling and Self-Organized Criticality from a Simulation Model of Early Complex Polities

    E-Print Network [OSTI]

    Griffin, Arthur F

    2011-01-01T23:59:59.000Z

    H. 1999, Chiefdoms and the Fission-Fusion Process, AmericanEmergence of Fusion/Fission Cycling and Self-Organizedliterature to describe the fusion and subsequent fission of

  9. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    aspects of a hybrid fusion-fission energy system called theof a Hybrid Fusion-Fission Nuclear Energy System by Kevinof a Hybrid Fusion-Fission Nuclear Energy System by Kevin

  10. Spontaneous Muon Emission during Fission, a New Nuclear Radioactivity

    E-Print Network [OSTI]

    D. B. Ion; M. L. D. Ion; Reveica Ion-Mihai

    2011-01-24T23:59:59.000Z

    In this paper the essential theoretical predictions for the nuclear muonic radioactivity are presented by using a special fission-like model similar with that used in description of the pionic emission during fission. Hence, a fission-like model for the muonic radioactivity takes into account the essential degree of freedom of the system: muon-fissility, muon-fission barrier height, etc. Using this model it was shown that most of the SHE-nuclei lie in the region where the muonic fissility parameters attain their limiting value X=1. Hence, the SHE-region is characterized by the absence of a classical barrier toward spontaneous muon and pion emissions. Numerical estimations on the yields for the natural muonic radioactivities of the transuranium elements as well numerical values for barrier heights are given only for even-even parent nuclei. Some experimental results from LCP-identification emission spectrum are reviewed. Also, the experimental results obtained by Khryachkov et al, using new spectrometer for investigation of ternary nuclear fission, are presented. The OPERA-experiment proposed to perform search for muonic radioactivity from lead nuclei, in the low background conditions offered by the Gran Sasso underground Laboratory (LNGS), is discussed.

  11. Fission gas release restrictor for breached fuel rod

    DOE Patents [OSTI]

    Kadambi, N. Prasad (Gaithersburg, MD); Tilbrook, Roger W. (Monroeville, PA); Spencer, Daniel R. (Unity Twp., PA); Schwallie, Ambrose L. (Greensburg, PA)

    1986-01-01T23:59:59.000Z

    In the event of a breach in the cladding of a rod in an operating liquid metal fast breeder reactor, the rapid release of high-pressure gas from the fission gas plenum may result in a gas blanketing of the breached rod and rods adjacent thereto which impairs the heat transfer to the liquid metal coolant. In order to control the release rate of fission gas in the event of a breached rod, the substantial portion of the conventional fission gas plenum is formed as a gas bottle means which includes a gas pervious means in a small portion thereof. During normal reactor operation, as the fission gas pressure gradually increases, the gas pressure interiorly of and exteriorly of the gas bottle means equalizes. In the event of a breach in the cladding, the gas pervious means in the gas bottle means constitutes a sufficient restriction to the rapid flow of gas therethrough that under maximum design pressure differential conditions, the fission gas flow through the breach will not significantly reduce the heat transfer from the affected rod and adjacent rods to the liquid metal heat transfer fluid flowing therebetween.

  12. Initial Back-to-Back Fission Chamber Testing in ATRC

    SciTech Connect (OSTI)

    Benjamin Chase; Troy Unruh; Joy Rempe

    2014-06-01T23:59:59.000Z

    Development and testing of in-pile, real-time neutron sensors for use in Materials Test Reactor experiments is an ongoing project at Idaho National Laboratory. The Advanced Test Reactor National Scientific User Facility has sponsored a series of projects to evaluate neutron detector options in the Advanced Test Reactor Critical Facility (ATRC). Special hardware was designed and fabricated to enable testing of the detectors in the ATRC. Initial testing of Self-Powered Neutron Detectors and miniature fission chambers produced promising results. Follow-on testing required more experiment hardware to be developed. The follow-on testing used a Back-to-Back fission chamber with the intent to provide calibration data, and a means of measuring spectral indices. As indicated within this document, this is the first time in decades that BTB fission chambers have been used in INL facilities. Results from these fission chamber measurements provide a baseline reference for future measurements with Back-to-Back fission chambers.

  13. Electron-capture delayed fission in {sup 246}Es

    SciTech Connect (OSTI)

    Shaughnessy, D.A.; Gregorich, K.E.; Hendricks, M.B.; Lane, M.R. [Lawrence Berkeley National Lab., CA (United States)] [and others

    1997-12-31T23:59:59.000Z

    We have extended our systematic study of electron-capture delayed fission (ECDF) in neutron-deficient isotopes to {sup 246}Es. The {sup 246}Es was produced at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory via the {sup 249}Cf(p,xn){sup 250-x}Es reaction with 37 MeV protons. There were 19 {sup 249}Cf targets used simultaneously in our light ion multiple (LIM) target system. Alpha particles and fission fragments were detected in our rotating wheel system. In some experiments, TTA extractions were performed to remove interfering activities. The chemically separated samples were positioned between a solid-state particle detector and two x-rays detectors. This configuration enabled us to look for fissions in coincidence with K x-rays following electron-capture. Our measured production cross section of 13 {+-} 5 {mu}b for {sup 246}Es was much lower than the cross section predicted by a neutron evaporation code. The probability of delayed fission was determined from the number of x-ray/fission coincidences measured.

  14. The behavior of fission products during nuclear rocket reactor tests

    SciTech Connect (OSTI)

    Bokor, P.C.; Kirk, W.L.; Bohl, R.J.

    1991-01-01T23:59:59.000Z

    The experience base regarding fission product behavior developed during the Rover program, the nuclear rocket development program of 1955--1972, will be useful in planning a renewed nuclear rocket program. During the Rover program, 20 reactors were tested at the Nuclear Rocket Development Station in Nevada. Nineteen of these discharged effluent directly into the atmosphere; the last reactor tested, a non-flight-prototypic, fuel-element-testing reactor called the Nuclear Furnace (NF-1) was connected to an effluent cleanup system that removed fission products before the hydrogen coolant (propellant) was discharged to the atmosphere. In general, we are able to increase both test duration and fuel temperature during the test series. Therefore fission product data from the later part of the program are more interesting and more applicable to future reactors. We have collected fission product retention (and release) data reported in both formal and informal publications for six of the later reactor tests; five of these were Los Alamos reactors that were firsts of a kind in configuration or operating conditions. We have also, with the cooperation of Westinghouse, included fission product data from the NRX-A6 reactor, the final member of series of developmental reactors with the same basic geometry, but with significant design and fabrication improvements as the series continued. Table 1 lists the six selected reactors and the test parameters for each.

  15. Comparison of Fission Product Yields and Their Impact

    SciTech Connect (OSTI)

    S. Harrison

    2006-02-01T23:59:59.000Z

    This memorandum describes the Naval Reactors Prime Contractor Team (NRPCT) Space Nuclear Power Program (SNPP) interest in determining the expected fission product yields from a Prometheus-type reactor and assessing the impact of these species on materials found in the fuel element and balance of plant. Theoretical yield calculations using ORIGEN-S and RACER computer models are included in graphical and tabular form in Attachment, with focus on the desired fast neutron spectrum data. The known fission product interaction concerns are the corrosive attack of iron- and nickel-based alloys by volatile fission products, such as cesium, tellurium, and iodine, and the radiological transmutation of krypton-85 in the coolant to rubidium-85, a potentially corrosive agent to the coolant system metal piping.

  16. Neutron emission and fragment yield in high-energy fission

    SciTech Connect (OSTI)

    Grudzevich, O. T., E-mail: ogrudzevich@ippe.ru; Klinov, D. A. [Institute for Physics and Power Engineering (Russian Federation)] [Institute for Physics and Power Engineering (Russian Federation)

    2013-07-15T23:59:59.000Z

    The KRIS special library of spectra and emission probabilities in the decays of 1500 nuclei excited up to energies between 150 and 250 MeV was developed for correctly taking into account the decay of highly excited nuclei appearing as fission fragments. The emission of neutrons, protons, and photons was taken into account. Neutron emission fromprimary fragments was found to have a substantial effect on the formation of yields of postneutron nuclei. The library was tested by comparing the calculated and measured yields of products originating from the fission of nuclei that was induced by high-energy protons. The method for calculating these yields was tested on the basis of experimental data on the thermal-neutroninduced fission of {sup 235}U nuclei.

  17. Microscopic description of Cf-252 cold fission yields

    E-Print Network [OSTI]

    M. Mirea; D. S. Delion; A. Sandulescu

    2009-07-20T23:59:59.000Z

    We investigate the cold fission of 252Cf within the two center shell model to compute the potential energy surface. The fission yields are estimated by using the semiclassical penetration approach. It turns out that the inner cold valley of the total potential energy is strongly connected with Z=50 magic number. The agreement with experimental values is very much improved only by considering mass and charge asymmetry degrees of freedom. Thus, indeed cold fission of 252Cf is a Sn-like radioactivity, related the other two "magic radioactivities", namely alpha-decay and heavy-cluster decay, called also Pb-like radioactivity. This calculation provides the necessary theoretical confidence to estimate the penetration cross section in producing superheavy nuclei, by using the inverse fusion process.

  18. Microscopic description of Cf-252 cold fission yields

    E-Print Network [OSTI]

    Mirea, M; Sandulescu, A

    2009-01-01T23:59:59.000Z

    We investigate the cold fission of 252Cf within the two center shell model to compute the potential energy surface. The fission yields are estimated by using the semiclassical penetration approach. It turns out that the inner cold valley of the total potential energy is strongly connected with Z=50 magic number. The agreement with experimental values is very much improved only by considering mass and charge asymmetry degrees of freedom. Thus, indeed cold fission of 252Cf is a Sn-like radioactivity, related the other two "magic radioactivities", namely alpha-decay and heavy-cluster decay, called also Pb-like radioactivity. This calculation provides the necessary theoretical confidence to estimate the penetration cross section in producing superheavy nuclei, by using the inverse fusion process.

  19. Sputtering yield of Pu bombarded by fission Fragments from Cf

    SciTech Connect (OSTI)

    Danagoulian, Areg [Los Alamos National Laboratory; Klein, Andreas [Los Alamos National Laboratory; Mcneil, Wendy V [Los Alamos National Laboratory; Yuan, Vincent W [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    We present results on the yield of sputtering of Pu atoms from a Pu foil, bombarded by fission fragments from a {sup 252}Cf source in transmission geometry. We have found the number of Pu atoms/incoming fission fragments ejected to be 63 {+-} 1. In addition, we show measurements of the sputtering yield as a function of distance from the central axis, which can be understood as an angular distribution of the yield. The results are quite surprising in light of the fact that the Pu foil is several times the thickness of the range of fission fragment particles in Pu. This indicates that models like the binary collision model are not sufficient to explain this behavior.

  20. Detecting a Nuclear Fission Reactor at the Center of the Earth

    E-Print Network [OSTI]

    R. S. Raghavan

    2002-08-24T23:59:59.000Z

    A natural nuclear fission reactor with a power output of 3- 10 terawatt at the center of the earth has been proposed as the energy source of the earth's magnetic field. The proposal can be directly tested by a massive liquid scintillation detector that can detect the signature spectrum of antineutrinos from the geo-reactor as well as the direction of the antineutrino source. Such detectors are now in operation or under construction in Japan/Europe. However, the clarity of both types of measurements may be limited by background from antineutrinos from surface power reactors. Future U. S. detectors, relatively more remote from power reactors, may be more suitable for achieving unambiguous spectral and directional evidence for a 3TW geo-reactor.

  1. Tunneling through equivalent multihumped fission barriers: Some implications for the actinide nuclei

    SciTech Connect (OSTI)

    Bhandari, B.S.; Al-Kharam, A.S.

    1989-03-01T23:59:59.000Z

    A comparison of the penetrabilities calculated in the Wentzel-Kramers-Brillouin approximation through equivalent multihumped fission barriers shows that the penetrability saturates to its maximum value much more slowly for a three-humped potential than that for comparable two-humped and single-humped potentials. An analysis of the slopes of the near-barrier photofission cross sections of actinides yields results that can be understood in terms of the predicted potential barrier shapes for these nuclei, and thus provides evidence in support of resolving the ''thorium anomaly'' along the lines suggested by Moeller and Nix. Our results further indicate that the uranium nuclei, and in particular /sup 236/U, may more likely exhibit three-humped potential shapes in which the apparent consequences of both the second and third minima may be observable.

  2. Development of fission gas swelling and release models for metallic nuclear fuels

    E-Print Network [OSTI]

    Andrews, Nathan Christopher

    2012-01-01T23:59:59.000Z

    Fuel swelling and fission gas generation for fast reactor fuels are of high importance since they are among the main limiting factors in the development of metallic fast reactor fuel. Five new fission gas and swelling ...

  3. asymmetric nucleon-induced fission: Topics by E-print Network

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

    J. A. Sheikh; A. Staszczak; M. Warda 2014-06-26 27 Benchmarking Nuclear Fission Theory Nuclear Experiment (arXiv) Summary: We suggest a small set of fission observables...

  4. Comparison of various parametrizations of the double-humped fission barrier

    SciTech Connect (OSTI)

    Bhandari, B.S.; Khaliquzzaman, M. (Physics Department, Faculty of Science, University of Garyounis, Benghazi, Libya (LY))

    1991-07-01T23:59:59.000Z

    The double-humped potential barriers in actinide nuclei in the fission direction have been parametrized using three different procedures, namely, the smoothly joined parabolic segments, third-degree polynomials passing through and with zero slopes at the successive extremum points, and straight-line segments connecting the successive extremum points. The fission penetrabilities through the barriers and the ground-state spontaneous fission half-lives for a wide variety of 25 actinide nuclides have been calculated for these different parametrizations. Our results clearly indicate that while the third-degree polynomial and the straight-line parametrizations of the double-humped fission barrier lead to approximately similar results on the fission penetrability and fission half-lives, the corresponding results using the smoothly joined parabolic segment parametrization differ significantly by almost two to five orders of magnitude depending on the specific type of the fissioning nucleus and on the parameters of its corresponding double-humped fission barrier.

  5. Construction of the first compendium of chemical-genetic profiles in the fission yeast Schizosaccharomyces pombe and comparative compendium approach

    SciTech Connect (OSTI)

    Han, Sangjo [Bioinformatics Lab, Healthcare Group, SK Telecom, 9-1, Sunae-dong, Pundang-gu, Sungnam-si, Kyunggi-do 463-784 (Korea, Republic of)] [Bioinformatics Lab, Healthcare Group, SK Telecom, 9-1, Sunae-dong, Pundang-gu, Sungnam-si, Kyunggi-do 463-784 (Korea, Republic of); Lee, Minho [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)] [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Chang, Hyeshik [Department of Biological Science, Seoul National University, 599 Gwanakro, Gwanak-gu, Seoul 151-747 (Korea, Republic of)] [Department of Biological Science, Seoul National University, 599 Gwanakro, Gwanak-gu, Seoul 151-747 (Korea, Republic of); Nam, Miyoung [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764 (Korea, Republic of)] [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764 (Korea, Republic of); Park, Han-Oh [Bioneer Corp., 8-11 Munpyeongseo-ro, Daedeok-gu, Daejeon 306-220 (Korea, Republic of)] [Bioneer Corp., 8-11 Munpyeongseo-ro, Daedeok-gu, Daejeon 306-220 (Korea, Republic of); Kwak, Youn-Sig [Department of Applied Biology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 660-701 (Korea, Republic of)] [Department of Applied Biology, Gyeongsang National University, 501 Jinju-daero, Jinju, Gyeongnam 660-701 (Korea, Republic of); Ha, Hye-jeong [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of)] [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of); Kim, Dongsup [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)] [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Hwang, Sung-Ook [Department of Obstetrics and Gynecology, Inha University Hospital, 7-206 Sinheung-dong, Jung-gu, Incheon 400-711 (Korea, Republic of)] [Department of Obstetrics and Gynecology, Inha University Hospital, 7-206 Sinheung-dong, Jung-gu, Incheon 400-711 (Korea, Republic of); Hoe, Kwang-Lae [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764 (Korea, Republic of)] [Department of New Drug Discovery and Development, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon, 305-764 (Korea, Republic of); Kim, Dong-Uk [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of)] [Aging Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), 125 Gwahak-ro, Yuseong-Gu, Daejeon 305-806 (Korea, Republic of)

    2013-07-12T23:59:59.000Z

    Highlights: •The first compendium of chemical-genetic profiles form fission yeast was generated. •The first HTS of drug mode-of-action in fission yeast was performed. •The first comparative chemical genetic analysis between two yeasts was conducted. -- Abstract: Genome-wide chemical genetic profiles in Saccharomyces cerevisiae since the budding yeast deletion library construction have been successfully used to reveal unknown mode-of-actions of drugs. Here, we introduce comparative approach to infer drug target proteins more accurately using two compendiums of chemical-genetic profiles from the budding yeast S. cerevisiae and the fission yeast Schizosaccharomyces pombe. For the first time, we established DNA-chip based growth defect measurement of genome-wide deletion strains of S. pombe, and then applied 47 drugs to the pooled heterozygous deletion strains to generate chemical-genetic profiles in S. pombe. In our approach, putative drug targets were inferred from strains hypersensitive to given drugs by analyzing S. pombe and S. cerevisiae compendiums. Notably, many evidences in the literature revealed that the inferred target genes of fungicide and bactericide identified by such comparative approach are in fact the direct targets. Furthermore, by filtering out the genes with no essentiality, the multi-drug sensitivity genes, and the genes with less eukaryotic conservation, we created a set of drug target gene candidates that are expected to be directly affected by a given drug in human cells. Our study demonstrated that it is highly beneficial to construct the multiple compendiums of chemical genetic profiles using many different species. The fission yeast chemical-genetic compendium is available at (http://pombe.kaist.ac.kr/compendium)

  6. On numerical relations playing a role in nuclear fission

    E-Print Network [OSTI]

    G. Mouze; C. Ythier

    2012-01-18T23:59:59.000Z

    The key numbers useful for describing the fission process are the mass number of the primordial cluster of the fissioning system and the magic mass numbers 82 and 126 of the nascent light and heavy fragments. The mean mass number and the mean atomic number of the light fragments are linked to the mass number and to the atomic number of the primordial cluster by simple relationships. The value 54 of the mean atomic number of the heavy fragments is predicted by the nucleon phase model.

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

    SciTech Connect (OSTI)

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

    1984-01-01T23:59:59.000Z

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

  8. Methods to Collect, Compile, and Analyze Observed Short-lived Fission Product Gamma Data

    SciTech Connect (OSTI)

    Finn, Erin C.; Metz, Lori A.; Payne, Rosara F.; Friese, Judah I.; Greenwood, Lawrence R.; Kephart, Jeremy D.; Pierson, Bruce D.; Ellis, Tere A.

    2011-09-29T23:59:59.000Z

    A unique set of fission product gamma spectra was collected at short times (4 minutes to 1 week) on various fissionable materials. Gamma spectra were collected from the neutron-induced fission of uranium, neptunium, and plutonium isotopes at thermal, epithermal, fission spectrum, and 14-MeV neutron energies. This report describes the experimental methods used to produce and collect the gamma data, defines the experimental parameters for each method, and demonstrates the consistency of the measurements.

  9. Direct Energy Conversion Fission Reactor for the period December 1, 1999 through February 29, 2000

    SciTech Connect (OSTI)

    Brown, L.C.

    2000-03-20T23:59:59.000Z

    OAK B135 Direct Energy Conversion Fission Reactor for the period December 1, 1999 through February 29, 2000

  10. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2001-09-30T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JUNE 1, 2001 THROUGH SEPTEMBER 30, 2001

  11. Propagation of a solitary fission wave A. G. Osborne, G. D. Recktenwald, and M. R. Deinerta)

    E-Print Network [OSTI]

    Deinert, Mark

    Propagation of a solitary fission wave A. G. Osborne, G. D. Recktenwald, and M. R. Deinerta waves can arise that will propagate at constant velocity. Numerical studies have shown that fission the conditions required for a solitary fission wave to propagate at constant velocity. The results place strict

  12. Euratom Programme for Nuclear Research and Training FP7-Fission-2009 GUIDE FOR APPLICANTS

    E-Print Network [OSTI]

    De Cindio, Fiorella

    Euratom Programme for Nuclear Research and Training FP7-Fission-2009 1 GUIDE FOR APPLICANTS All Programme for Nuclear Research and Training FP7-Fission-2009 2 About this Guide This is version 4 (dated 19 does not supersede those documents. #12;Euratom Programme for Nuclear Research and Training FP7-Fission

  13. THE STUDY OF NUCLEAR FISSION INDUCED BY HIGH-ENERGY PROTONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    243 THE STUDY OF NUCLEAR FISSION INDUCED BY HIGH-ENERGY PROTONS R. BRANDT (*), F. CARBONARA (**), E been undertaken with the aim to measure cross-sections for nuclear fission of heavy nuclei induced by high-energy protons. Nuclear fission at high energies is defined here as a nuclear break-up into two

  14. PHYSICAL REVIEW C VOLUME 46, NUMBER 1 JULY 1992 Nuclear fission with diffusive dynamics

    E-Print Network [OSTI]

    Bertsch George F.

    PHYSICAL REVIEW C VOLUME 46, NUMBER 1 JULY 1992 Nuclear fission with diffusive dynamics D. Cha investigate the dynamics of nuclear fission, assuming purely diffusive motion up to the saddle point/BP=(Bp/BE' )(BE*/BP). Several authors have applied the Smoluchowski equation to nuclear fission processes

  15. APS/123-QED Probing Nuclear Shapes Close to the Fission Limit with the GDR in 216

    E-Print Network [OSTI]

    Benzoni, Giovanna

    APS/123-QED Probing Nuclear Shapes Close to the Fission Limit with the GDR in 216 Rn M. Kmiecik1. INTRODUCTION The mechanism of nuclear fission induced by fast ro- tation and the nuclear shape evolution information about the nuclear shape evolution along the fission path, it is possible to use at least two

  16. Microscopic description of nuclear fission (*) J.-F. Berger, M. Girod and D. Gogny

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    L-509 Microscopic description of nuclear fission (*) J.-F. Berger, M. Girod and D. Gogny Service de'une description complètement microscopique du noyau, nous tentons d'interpréter la fission du noyau 240Pu en of the nucleus, we try to extract the characteristic features of the collective dynamics of the fission

  17. Nuclear fission time measurements as a function of excitation energy. A crystal blocking experiment

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 1 - Nuclear fission time measurements as a function of excitation energy. A crystal blocking information on nuclear dissipation, and, in particular, long fission times (>10-18 s) that cannot be predicted, France Abstract : Fission times of lead and uranium nuclei have been measured at GANIL by the crystal

  18. SYMPOSIA AT THE ACADEMY ENRICO FERMI AND THE BEGINNINGS OF NUCLEAR FISSION

    E-Print Network [OSTI]

    Qian, Ning

    SYMPOSIA AT THE ACADEMY ENRICO FERMI AND THE BEGINNINGS OF NUCLEAR FISSION NOVEMBER 15-16, 2001, will host a two day symposium: Enrico Fermi and the Beginnings of Nuclear Fission. The focus Research Center, IBM Overview of the Origins of Nuclear Fission The Italian Period Malvin Ruderman

  19. NEANDC specialists meeting on yields and decay data of fission product nuclides

    SciTech Connect (OSTI)

    Chrien, R.E.; Burrows, T.W. (eds.)

    1983-01-01T23:59:59.000Z

    Separate abstracts were prepared for the 29 papers presented. Workshop reports on decay heat, fission yields, beta- and gamma-ray spectroscopy, and delayed neutrons are included. An appendix contains a survey of the most recent compilations and evaluations containing fission product yield, fission product decay data, and delayed neutron yield information. (WHK)

  20. Quantum mechanical method of fragment's angular and energy distribution calculation for binary and ternary fission

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V.; Pen'kov, N. V. [Voronezh State University (Russian Federation)

    2006-08-15T23:59:59.000Z

    In the framework of quantum-mechanical fission theory, the method of calculation for partial fission width amplitudes and asymptotic behavior of the fissile nucleus wave function with strong channel coupling taken into account has been suggested. The method allows one to solve the calculation problem of angular and energy distribution countation for binary and ternary fission.

  1. Excitation energy dependence of fission in the mercury region

    E-Print Network [OSTI]

    McDonnell, J D; Sheikh, J A; Staszczak, A; Warda, M

    2014-01-01T23:59:59.000Z

    Background: Recent experiments on beta-delayed fission reported an asymmetric mass yield in the neutron-deficient nucleus 180Hg. Earlier experiments in the mass region A=190-200 close to the beta-stability line, using the (p,f) and (\\alpha,f) reactions, observed a more symmetric distribution of fission fragments. While the beta-delayed fission of 180Hg can be associated with relatively low excitation energy, this is not the case for light-ion reactions, which result in warm compound nuclei. Purpose: To elucidate the roles of proton and neutron numbers and excitation energy in determining symmetric and asymmetric fission yields, we compute and analyze the isentropic potential energy surfaces of 174,180,198Hg and 196,210Po. Methods: We use the finite-temperature superfluid nuclear density functional theory, for excitation energies up to E*=30MeV and zero angular momentum. For our theoretical framework, we consider the Skyrme energy density functional SkM* and a density-dependent pairing interaction. Results: Fo...

  2. Validation of MCNPX-PoliMi Fission Models

    SciTech Connect (OSTI)

    S. A. Pozzi; S. D. Clarke; W. Walsh; E. C. Miller; J. Dolan; M. Flaska; B. M. Wieger; A. Enqvist; E. Padovani; J. K. Mattingly; D. L. Chichester; P. Peerani

    2012-10-01T23:59:59.000Z

    We present new results on the measurement of correlated, outgoing neutrons from spontaneous fission events in a Cf-252 source. 16 EJ-309 liquid scintillation detectors are used to measure neutron-neutron correlations for various detector angles. Anisotropy in neutron emission is observed. The results are compared to MCNPX-PoliMi simulations and good agreement is observed.

  3. Characteristics of the samples in the FNG fission deposit collection

    SciTech Connect (OSTI)

    Meadows, J.W.

    1990-12-01T23:59:59.000Z

    Information concerning the samples in the Fast Neutron Generator (FNG) Group's fission deposit collection has been assembled. This includes the physical dimensions, isotopic analyses, half-lives, alpha emission rates specific activities and deposit weights. 10 refs., 9 figs., 5 tabs.

  4. Monte Carlo based toy model for fission process

    SciTech Connect (OSTI)

    Kurniadi, R., E-mail: rijalk@fi.itb.ac.id; Waris, A., E-mail: rijalk@fi.itb.ac.id; Viridi, S., E-mail: rijalk@fi.itb.ac.id [Department of Physics, Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung (Indonesia)

    2014-09-30T23:59:59.000Z

    There are many models and calculation techniques to obtain visible image of fission yield process. In particular, fission yield can be calculated by using two calculations approach, namely macroscopic approach and microscopic approach. This work proposes another calculation approach in which the nucleus is treated as a toy model. Hence, the fission process does not represent real fission process in nature completely. The toy model is formed by Gaussian distribution of random number that randomizes distance like the distance between particle and central point. The scission process is started by smashing compound nucleus central point into two parts that are left central and right central points. These three points have different Gaussian distribution parameters such as mean (?{sub CN}, ?{sub L}, ?{sub R}), and standard deviation (?{sub CN}, ?{sub L}, ?{sub R}). By overlaying of three distributions, the number of particles (N{sub L}, N{sub R}) that are trapped by central points can be obtained. This process is iterated until (N{sub L}, N{sub R}) become constant numbers. Smashing process is repeated by changing ?{sub L} and ?{sub R}, randomly.

  5. Temperature-Dependent Fission Barriers of Superheavy Nuclei

    E-Print Network [OSTI]

    Pei, J C; Sheikh-Javid, A; Kerman, A K

    2009-01-01T23:59:59.000Z

    The dependence of fission barriers on the excitation energy of the compound nucleus impacts the survival probability of superheavy nuclei synthesized in heavy-ion fusion reactions. We study the temperature-dependent fission barriers by means of the self-consistent nuclear density functional theory. The equivalence of isothermal and isentropic descriptions is demonstrated. The effect of the particle gas is found to be negligible in the range of temperatures studied. Calculations have been carried out for $^{264}$Fm, $^{272}$Ds, $^{278}$112, $^{292}$114, and $^{312}$124. For nuclei around $^{278}$112 produced in "cold fusion" reactions, we predict a more rapid decrease of fission barriers with temperature as compared to the nuclei around $^{292}$114 synthesized in "hot fusion" experiments. This is explained in terms of the difference between the ground-state and fission-barrier temperatures. Our calculations are consistent with the long survival probabilities of the superheavy elements produced in Dubna with th...

  6. A brief history of the Delayed'' discovery of nuclear fission

    SciTech Connect (OSTI)

    Holden, N.E.

    1989-08-01T23:59:59.000Z

    This year marks the Fiftieth Anniversary of the discovery of Nuclear Fission. In the early 1930's, the neutron was discovered, followed by the discovery of artificial radioactivity and then the use of the neutron to produce artificial radioactivity. The first experiments resulting in the fission of uranium took place in 1934. A paper which speculated on fission as an explanation was almost immediately published, yet no one took it seriously not even the author herself. Why did it take an additional five years before anyone realized what had occurred This is an abnormally long time in a period when discoveries, particularly in nuclear physics, seemed to be almost a daily occurrence. The events which led up to the discovery are recounted, with an attempt made to put them into their historical perspective. The role played by Mendeleev's Periodic Table, the role of the natural radioactive decay chain of uranium, the discovery of protactinium, the apparent discovery of masurium (technetium) and a speculation on the reason why Irene Curie may have missed the discovery of nuclear fission will all be discussed. 43 refs.

  7. High Efficiency Organic Multilayer Photodetectors based on Singlet Fission ....................................................................................................................................................................................

    E-Print Network [OSTI]

    Reif, Rafael

    .........................................................................................................................PH.14 High-efficiency, Low-cost Photovoltaics using III-V on Silicon Tandem CellsPhotonics High Efficiency Organic Multilayer Photodetectors based on Singlet Fission.........................................................................................................................PH.2 Efficiently Coupling Light to Superconducting Nanowire Single-photon Detectors

  8. Reactor as a Source of Antineutrinos: Thermal Fission Energy

    E-Print Network [OSTI]

    V. Kopeikin; L. Mikaelyan; V. Sinev

    2004-10-07T23:59:59.000Z

    Deeper insight into the features of a reactor as a source of antineutrinos is required for making further advances in studying the fundamental properties of the neutrino. The relationship between the thermal power of a reactor and the rate of the chain fission reaction in its core is analyzed.

  9. Recent MELCOR and VICTORIA Fission Product Research at the NRC

    SciTech Connect (OSTI)

    Bixler, N.E.; Cole, R.K.; Gauntt, R.O.; Schaperow, J.H.; Young, M.F.

    1999-01-21T23:59:59.000Z

    The MELCOR and VICTORIA severe accident analysis codes, which were developed at Sandia National Laboratories for the U. S. Nuclear Regulatory Commission, are designed to estimate fission product releases during nuclear reactor accidents in light water reactors. MELCOR is an integrated plant-assessment code that models the key phenomena in adequate detail for risk-assessment purposes. VICTORIA is a more specialized fission- product code that provides detailed modeling of chemical reactions and aerosol processes under the high-temperature conditions encountered in the reactor coolant system during a severe reactor accident. This paper focuses on recent enhancements and assessments of the two codes in the area of fission product chemistry modeling. Recently, a model for iodine chemistry in aqueous pools in the containment building was incorporated into the MELCOR code. The model calculates dissolution of iodine into the pool and releases of organic and inorganic iodine vapors from the pool into the containment atmosphere. The main purpose of this model is to evaluate the effect of long-term revolatilization of dissolved iodine. Inputs to the model include dose rate in the pool, the amount of chloride-containing polymer, such as Hypalon, and the amount of buffering agents in the containment. Model predictions are compared against the Radioiodine Test Facility (RTF) experiments conduced by Atomic Energy of Canada Limited (AECL), specifically International Standard Problem 41. Improvements to VICTORIA's chemical reactions models were implemented as a result of recommendations from a peer review of VICTORIA that was completed last year. Specifically, an option is now included to model aerosols and deposited fission products as three condensed phases in addition to the original option of a single condensed phase. The three-condensed-phase model results in somewhat higher predicted fission product volatilities than does the single-condensed-phase model. Modeling of U02 thermochemistry was also improved, and results in better prediction of vaporization of uranium from fuel, which can react with released fission products to affect their volatility. This model also improves the prediction of fission product release rates from fuel. Finally, recent comparisons of MELCOR and VICTORIA with International Standard Problem 40 (STORM) data are presented. These comparisons focus on predicted therrnophoretic deposition, which is the dominant deposition mechanism. Sensitivity studies were performed with the codes to examine experimental and modeling uncertainties.

  10. Fast Track Dredged Material Decontamination

    E-Print Network [OSTI]

    Brookhaven National Laboratory

    Fast Track Dredged Material Decontamination Demonstration for the Port of New York and New Jersey Department of Energy Brookhaven National Laboratory Fast Track Dredged Material Decontamination Demonstration .............................................................................. 3 3.3 Relation to the U.S. Army Corps of Engineers-New York District Dredged Material Management

  11. BSTBacterial Source Tracking Conference Proceedings

    E-Print Network [OSTI]

    BSTBacterial Source Tracking Conference Proceedings 2012 Bacterial Source Tracking State Conference Conference Proceedings Prepared by: Lucas Gregory, Texas Water Resources Institute Courtney Smith of the Science Conference Texas Water Resources Institute TR-427 June 2012 #12;#12;Texas Water Resources

  12. Environmental Studies Minor Sustainability Track

    E-Print Network [OSTI]

    , and decision-making in pursuit of sustainability goals Example courses: ECON 75 Environmental and Energy2/17/14 Environmental Studies Minor Sustainability Track W O R K S H E E T The sustainability track (numbered 10 or above) 1. One course in team problem-solving or design/innovation for sustainability 2. One

  13. Phase 1 Space Fission Propulsion Energy Source Design

    SciTech Connect (OSTI)

    Houts, Mike; Van Dyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbud, Ivana; Carter, Robert [NASA MSFC, TD40, Marshall Space Flight Center, Alabama, 35812 (United States)

    2002-07-01T23:59:59.000Z

    Fission technology can enable rapid, affordable access to any point in the solar system. If fission propulsion systems are to be developed to their full potential; however, near-term customers must be identified and initial fission systems successfully developed, launched, and operated. Studies conducted in fiscal year 2001 (IISTP, 2001) show that fission electric propulsion (FEP) systems with a specific mass at or below 50 kg/kWjet could enhance or enable numerous robotic outer solar system missions of interest. At the required specific mass, it is possible to develop safe, affordable systems that meet mission requirements. To help select the system design to pursue, eight evaluation criteria were identified: system integration, safety, reliability, testability, specific mass, cost, schedule, and programmatic risk. A top-level comparison of four potential concepts was performed: a Testable, Passive, Redundant Reactor (TPRR), a Testable Multi-Cell In-Core Thermionic Reactor (TMCT), a Direct Gas Cooled Reactor (DGCR), and a Pumped Liquid Metal Reactor (PLMR). Development of any of the four systems appears feasible. However, for power levels up to at least 500 kWt (enabling electric power levels of 125-175 kWe, given 25-35% power conversion efficiency) the TPRR has advantages related to several criteria and is competitive with respect to all. Hardware-based research and development has further increased confidence in the TPRR approach. Successful development and utilization of a 'Phase 1' fission electric propulsion system will enable advanced Phase 2 and Phase 3 systems capable of providing rapid, affordable access to any point in the solar system. (authors)

  14. DOUBLE TRACKS Test Site interim corrective action plan

    SciTech Connect (OSTI)

    NONE

    1996-06-01T23:59:59.000Z

    The DOUBLE TRACKS site is located on Range 71 north of the Nellis Air Force Range, northwest of the Nevada Test Site (NTS). DOUBLE TRACKS was the first of four experiments that constituted Operation ROLLER COASTER. On May 15, 1963, weapons-grade plutonium and depleted uranium were dispersed using 54 kilograms of trinitrotoluene (TNT) explosive. The explosion occurred in the open, 0.3 m above the steel plate. No fission yield was detected from the test, and the total amount of plutonium deposited on the ground surface was estimated to be between 980 and 1,600 grams. The test device was composed primarily of uranium-238 and plutonium-239. The mass ratio of uranium to plutonium was 4.35. The objective of the corrective action is to reduce the potential risk to human health and the environment and to demonstrate technically viable and cost-effective excavation, transportation, and disposal. To achieve these objectives, Bechtel Nevada (BN) will remove soil with a total transuranic activity greater then 200 pCI/g, containerize the soil in ``supersacks,`` transport the filled ``supersacks`` to the NTS, and dispose of them in the Area 3 Radioactive Waste Management Site. During this interim corrective action, BN will also conduct a limited demonstration of an alternative method for excavation of radioactive near-surface soil contamination.

  15. Molten salt extraction of transuranic and reactive fission products from used uranium oxide fuel

    DOE Patents [OSTI]

    Herrmann, Steven Douglas

    2014-05-27T23:59:59.000Z

    Used uranium oxide fuel is detoxified by extracting transuranic and reactive fission products into molten salt. By contacting declad and crushed used uranium oxide fuel with a molten halide salt containing a minor fraction of the respective uranium trihalide, transuranic and reactive fission products partition from the fuel to the molten salt phase, while uranium oxide and non-reactive, or noble metal, fission products remain in an insoluble solid phase. The salt is then separated from the fuel via draining and distillation. By this method, the bulk of the decay heat, fission poisoning capacity, and radiotoxicity are removed from the used fuel. The remaining radioactivity from the noble metal fission products in the detoxified fuel is primarily limited to soft beta emitters. The extracted transuranic and reactive fission products are amenable to existing technologies for group uranium/transuranic product recovery and fission product immobilization in engineered waste forms.

  16. SOFTWARE QUALITY & SYSTEMS ENGINEERING PROGRAM: Project Tracking...

    Office of Environmental Management (EM)

    Project Tracking Checklist SOFTWARE QUALITY & SYSTEMS ENGINEERING PROGRAM: Project Tracking Checklist The following checklist is intended to provide system owners, project...

  17. Increasing Scientific Productivity by Tracking Data

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

    Data Tracking Increases Scientific Productivity Data Tracking Increases Scientific Productivity July 20, 2011 | Tags: HPSS, NERSC Linda Vu, lvu@lbl.gov, +1 510 486 2402 HPSS...

  18. Midwest Renewable Energy Tracking System (Multiple States)

    Broader source: Energy.gov [DOE]

    The Midwest Renewable Energy Tracking System (M-RETS®) tracks renewable energy generation in participating States and Provinces and assists in verifying compliance with individual state/provincial...

  19. Cooperative Modeling and Design History Tracking Using Design Tracking Matrix

    E-Print Network [OSTI]

    Kim, Jonghyun

    2010-10-12T23:59:59.000Z

    This thesis suggests a new framework for cooperative modeling which supports concurrency design protocol with a design history tracking function. The proposed framework allows designers to work together while eliminating design conflicts...

  20. Abrasion resistant track shoe grouser

    DOE Patents [OSTI]

    Fischer, Keith D; Diekevers, Mark S; Afdahl, Curt D; Steiner, Kevin L; Barnes, Christopher A

    2013-04-23T23:59:59.000Z

    A track shoe for a track-type vehicle. The track shoe includes a base plate and a grouser projecting away from the base plate. A capping surface structure of substantially horseshoe shaped cross-section is disposed across a distal portion of the grouser. The capping surface structure covers portions of a distal edge surface and adjacent lateral surfaces. The capping surface structure is formed from an material characterized by enhanced wear resistance relative to portions of the grouser underlying the capping surface structure.

  1. Singlet fission in tetracene and rubrene: evidence for the direct formation

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebookScholarship Fund3 Outlook for GulfSimulationsApplications

  2. Top marine predators track Lagrangian coherent structures

    E-Print Network [OSTI]

    E. Tew Kai; V. Rossi; J. Sudre; H. Weimerskirch; C. Lopez; E. Hernandez-Garcia; F. Marsac; V. Garcon

    2009-04-13T23:59:59.000Z

    Meso- and submesoscales (fronts, eddies, filaments) in surface ocean flow have a crucial influence on marine ecosystems. Their dynamics partly control the foraging behaviour and the displacement of marine top predators (tuna, birds, turtles, and cetaceans). In this work we focus on the role of submesoscale structures in the Mozambique Channel on the distribution of a marine predator, the Great Frigatebird. Using a newly developed dynamical concept, namely the Finite-Size Lyapunov Exponent (FSLE), we have identified Lagrangian coherent structures (LCSs) present in the surface flow in the Channel over a 2-month observation period (August and September 2003). By comparing seabirds' satellite positions with LCSs locations, we demonstrate that frigatebirds track precisely these structures in the Mozambique Channel, providing the first evidence that a top predator is able to track these FSLE ridges to locate food patches. After comparing bird positions during long and short trips, and different parts of these trips, we propose several hypotheses to understand how frigatebirds can follow these LCSs. The birds might use visual and/or olfactory cues and/or atmospheric current changes over the structures to move along these biological corridors. The birds being often associated to tuna schools around foraging areas, a thorough comprehension of their foraging behaviour and movement during the breeding season is crucial not only to seabirds' ecology but also to an appropriate ecosystemic approach of fisheries in the Channel.

  3. Fluorescent image tracking velocimeter

    DOE Patents [OSTI]

    Shaffer, Franklin D. (Library, PA)

    1994-01-01T23:59:59.000Z

    A multiple-exposure fluorescent image tracking velocimeter (FITV) detects and measures the motion (trajectory, direction and velocity) of small particles close to light scattering surfaces. The small particles may follow the motion of a carrier medium such as a liquid, gas or multi-phase mixture, allowing the motion of the carrier medium to be observed, measured and recorded. The main components of the FITV include: (1) fluorescent particles; (2) a pulsed fluorescent excitation laser source; (3) an imaging camera; and (4) an image analyzer. FITV uses fluorescing particles excited by visible laser light to enhance particle image detectability near light scattering surfaces. The excitation laser light is filtered out before reaching the imaging camera allowing the fluoresced wavelengths emitted by the particles to be detected and recorded by the camera. FITV employs multiple exposures of a single camera image by pulsing the excitation laser light for producing a series of images of each particle along its trajectory. The time-lapsed image may be used to determine trajectory and velocity and the exposures may be coded to derive directional information.

  4. Systematics of the deduced fission barriers for the doubly even transactinium nuclei

    SciTech Connect (OSTI)

    Bhandari, B.S.; Bendardaf, Y.B. (Department of Physics, Faculty of Science, University of Garyounis, Benghazi (Libya))

    1992-06-01T23:59:59.000Z

    The systematics of the fission barrier shapes of a total of 47 doubly even actinide and transactinide nuclei have been studied using the double-humped fission barrier model. The fission barrier has been parametrized in terms of four smoothly joined parabolic segments. The penetrabilities through such double-humped fission barriers have been calculated in the Wentzel-Kramers-Brillouin approximation, and the various fission half-lives have been determined using the formalism given earlier by Nix and Walker. The various parameters of such fission barriers have been deduced by requiring their simultaneous consistency with the various relevant fission observables, namely, the near-barrier fission cross sections, isomeric energies and isomeric half-lives, where available, and the ground-state spontaneous fission half-lives in the region 90{le}{ital Z}{le}98, and such model calculations with some further justifiable asssumptions have been extended to the region of the still heavier nuclei with {ital Z}{ge}100. The results of our systematic study of the heights of the inner and the outer barriers of the double-humped fission barriers corresponding to such doubly even nuclei suggest that while the height of the inner barrier remains approximately constant in the entire region of such nuclei, the deduced heights of the outer barrier decrease rather sharply and continuously with the increase in the value of the fissility parameter until one reaches the element Rf ({ital Z}=104).

  5. Quasi-fission reactions as a probe of nuclear viscosity

    E-Print Network [OSTI]

    J. Velkovska; C. R. Morton; R. L. McGrath; P. Chung; I. Dioszegi

    1998-10-24T23:59:59.000Z

    Fission fragment mass and angular distributions were measured from the ^{64}Ni+^{197}Au reaction at 418 MeV and 383 MeV incident energy. A detailed data analysis was performed, using the one-body dissipation theory implemented in the code HICOL. The effect of the window and the wall friction on the experimental observables was investigated. Friction stronger than one-body was also considered. The mass and angular distributions were consistent with one-body dissipation. An evaporation code DIFHEAT coupled to HICOL was developed in order to predict reaction time scales required to describe available data on pre-scission neutron multiplicities. The multiplicity data were again consistent with one-body dissipation. The cross-sections for touch, capture and quasi-fission were also obtained.

  6. Method of fission heat flux determination from experimental data

    DOE Patents [OSTI]

    Paxton, Frank A. (Schenectady, NY)

    1999-01-01T23:59:59.000Z

    A method is provided for determining the fission heat flux of a prime specimen inserted into a specimen of a test reactor. A pair of thermocouple test specimens are positioned at the same level in the holder and a determination is made of various experimental data including the temperature of the thermocouple test specimens, the temperature of bulk water channels located in the test holder, the gamma scan count ratios for the thermocouple test specimens and the prime specimen, and the thicknesses of the outer clads, the fuel fillers, and the backclad of the thermocouple test specimen. Using this experimental data, the absolute value of the fission heat flux for the thermocouple test specimens and prime specimen can be calculated.

  7. Delayed neutron data and group parameters for 43 fissioning systems

    SciTech Connect (OSTI)

    Brady, M.C. (Oak Ridge National Lab., TN (USA)); England, T.R. (Los Alamos National Lab., NM (USA))

    1989-10-01T23:59:59.000Z

    The quality and quantity of delayed neutron precursor data have greatly improved over the past decade and a half. Supplementation of the data with model calculations and the use of models to extend the number of precursors to 271 is now practical. These data, along with other improved fission product parameters, permit direct calculations of aggregate behavior for many fissioning nuclides. The results can still be approximated using a few (usually six) temporal groups, including corresponding spectra, as in past practice for reactor physics. An extensive effort to provide a complete set of evaluated data is summarized, with an emphasis on its use to generate the temporal approximations; precursor data and group values are intended for inclusion in ENDF/B-VI.

  8. Fission-product release from irradiated LWR fuel

    SciTech Connect (OSTI)

    Osborne, M.F.; Lorenz, R.A.; Wichner, R.P.

    1982-01-01T23:59:59.000Z

    An experimental investigation of fission product release from commercial LWR fuel under accident conditions is being conducted at Oak Ridge National Laboratory (ORNL). This work, which is sponsored by the US Nuclear Regulatory Commission (NRC), is an extension of earlier experiments up to 1600/sup 0/C and is designed to obtain the experimental data needed to reliably assess the consequences of accidents for fuel temperatures up to melting. The objectives of this program are (1) to determine fission product release rates from fully-irradiated commercial LWR fuel in high-temperature steam; (2) to collect and characterize the aerosol released; (3) to identify the chemical forms of the released material; (4) to correlate the results with related experimental data and develop a consistent source term model; and (5) to aid in the interpretation of tests using simulated LWR fuel.

  9. Plutonium detection with a new fission neutron survey meter

    SciTech Connect (OSTI)

    Klett, A. [EG and G Berthold, Bad Wildbad (Germany)] [EG and G Berthold, Bad Wildbad (Germany)

    1999-08-01T23:59:59.000Z

    The search for illicit trafficking or hidden plutonium sources has become a pressing issue, especially since the breakdown of the former Soviet Union. Plutonium is extremely dangerous and hard to detect over large distances. The {alpha}-particles and X-rays which are emitted by plutonium isotopes can easily be shielded by the material itself or by surroundings. Besides a few {gamma}`s, the only penetrating radiation emitted by plutonium samples are neutrons from spontaneous fission. Therefore a special neutron survey meter with unrivaled sensitivity for fission neutrons has been newly designed. The hand-held, commercially available instrument has an approximate weight of 4 kg and is battery driven. The neutron probe consists of a {sup 3}He proportional counter tube, a moderator and integrated electronics. The sensitivity is sufficient to detect plutonium masses below 100 g at a distance of 1 m within a few seconds.

  10. Master track Theoretical Biology & Bioinformatics

    E-Print Network [OSTI]

    Utrecht, Universiteit

    their master. Our two MSc courses "Computational Biology" and "Bioinformatics and Evolutionary GenomicsMaster track Theoretical Biology & Bioinformatics Modeling and bioinformatics is an important Biology & Bioinformatics provides courses introducing you to the basic concepts of modeling

  11. (Fission product transport experiments (HFR-B1))

    SciTech Connect (OSTI)

    Myers, B.F.

    1989-12-05T23:59:59.000Z

    Travel to the JRC Petten was for the purpose of discussing the HFR-B1 experiment and post irradiation activities. Technical assessment of the experiment strongly supports the concept of enhanced fission gas release at temperatures above 1100{degree}C, the extensive release of stored fission gas at water vapor levels postulated in accident scenarios, an increase in the steady-state fission gas release under hydrolyzing conditions, and an increase in gas release during thermal cycling. Schedules were established for completion of the work and issuance of reports by September 1990. At the KFA Juelich agreement was reached on the PIE activities for HFR-B1 and a schedule established. The final PIE report is due June 1991. Choices of accident condition tests in the PIE have yet to be made by the US participants. A proposal for the establishment of a new cooperative effort on model and code development was presented at the Institut fuer Nukleare Sicherheitsforschung of KFA. The proposal was considered premature; discussions dealing with general principles, basic aims, and organization were requested; particular concerns about free exchange of information, overlap with the existing safety subprogram, and exclusive cooperation with ORNL were raised. A strong desire for cooperation and the opinion that the raised problems could be resolved were expressed. Technical discussions at the KFA were beneficial.

  12. Monitoring system for a liquid-cooled nuclear fission reactor

    DOE Patents [OSTI]

    DeVolpi, Alexander (Bolingbrook, IL)

    1987-01-01T23:59:59.000Z

    A monitoring system for detecting changes in the liquid levels in various regions of a water-cooled nuclear power reactor, viz., in the downcomer, in the core, in the inlet and outlet plenums, at the head, and elsewhere; and also for detecting changes in the density of the liquid in these regions. A plurality of gamma radiation detectors are used, arranged vertically along the outside of the reactor vessel, and collimator means for each detector limits the gamma-radiation it receives as emitting from only isolated regions of the vessel. Excess neutrons produced by the fission reaction will be captured by the water coolant, by the steel reactor walls, or by the fuel or control structures in the vessel. Neutron capture by steel generates gamma radiation having an energy level of the order of 5-12 MeV, whereas neutron capture by water provides an energy level of approximately 2.2 MeV, and neutron capture by the fission fuel or its cladding provides an energy level of 1 MeV or less. The intensity of neutron capture thus changes significantly at any water-metal interface. Comparative analysis of adjacent gamma detectors senses changes from the normal condition with liquid coolant present to advise of changes in the presence and/or density of the coolant at these specific regions. The gamma detectors can also sense fission-product gas accumulation at the reactor head to advise of a failure of fuel-pin cladding.

  13. Direct fission fragment energy converter - Magnetic collimator option

    SciTech Connect (OSTI)

    Tsvetkov, P. V.; Hart, R. R. [Dept. of Nuclear Engineering, Texas AandM Univ., 129 Zachry Engineering Center, College Station, TX 77843-3133 (United States)

    2006-07-01T23:59:59.000Z

    The present study was focused on developing a technologically feasible power system that is based on direct fission fragment energy conversion utilizing magnetic collimation. The new concept is an attempt to combine several advantageous design solutions, which have been proposed for application in both fission and fusion reactors, into one innovative system that can offer exceptional energy conversion efficiency. The analysis takes into consideration a wide range of operational aspects including fission fragment escape from the fuel, collimation, collection, criticality, long-term performance, energy conversion efficiency, heat removal, and safety characteristics. Specific characteristics of the individual system components and the entire system are evaluated. Analysis and evaluation of the technological feasibility of the concept were achieved using state-of-the-art computer codes that allowed realistic and consistent modeling. In addition to the extensive computational effort, the scaled prototype experimental proof-of-principle program was conducted to validate basic physics of the concept. The program was focused on electromagnetic components and experimental demonstration of performance. This paper summarizes the final results of the 6-years research program including both computational and experimental efforts. Potential future research and development and anticipated applications are discussed. (authors)

  14. Nuclear fission and nuclear safeguards: Common technologies and challenges

    SciTech Connect (OSTI)

    Keepin, G.R.

    1989-01-01T23:59:59.000Z

    Nuclear fission and nuclear safeguards have much in common, including the basic physical phenomena and technologies involved as well as the commitments and challenges posed by expanding nuclear programs in many countries around the world. The unique characteristics of the fission process -- such as prompt and delayed neutron and gamma ray emission -- not only provide the means of sustaining and controlling the fission chain reaction, but also provide unique ''signatures'' that are essential to quantitative measurement and effective safeguarding of key nuclear materials (notably /sup 239/Pu and /sup 235/U) against theft, loss, or diversion. In this paper, we trace briefly the historical emergence of safeguards as an essential component of the expansion of the nuclear enterprise worldwide. We then survey the major categories of passive and active nondestructive assay techniques that are currently in use or under development for rapid, accurate measurement and verification of safe-guarded nuclear materials in the many forms in which they occur throughout the nuclear fuel cycle. 23 refs., 14 figs.

  15. Theory in evaluation of actinide fission and capture cross sections.

    SciTech Connect (OSTI)

    Lynn, J. E. (J. Eric)

    2004-01-01T23:59:59.000Z

    The authors discuss the possibilities and limitations of the use of theory as a tool in the evaluation of actinide fission and capture cross-sections. They consider especially the target {sup 235}U as an example. They emphasize the roles of intermediate structure in the fission cross-section and of level width fluctuations in both intermediate structure and fine structure, noting that these lead to a breakdown of Hauser-Feshbach theory at sub-barrier and near barrier energies. At higher energies (where fluctuation-averaged Hauser-Feshbach theory is applicable) semi-quantitative and intuitive representations of transition state spectra and barrier level density functions have to be tested against experimental data wherever these are available. Adjustment of the fission cross-section against inelastic scattering to the much better known levels of the residual nucleus should then lead to a fairly sound estimate of the capture cross-section. They compare such estimates with evaluated and experimental data for {sup 235}U.

  16. Track 4: Employee Health and Wellness

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 4: Employee Health and Wellness

  17. Fission time-scale in experiments and in multiple initiation model

    SciTech Connect (OSTI)

    Karamian, S. A., E-mail: karamian@nrmail.jinr.ru [Joint Institute for Nuclear Research (Russian Federation)

    2011-12-15T23:59:59.000Z

    Rate of fission for highly-excited nuclei is affected by the viscose character of the systemmotion in deformation coordinates as was reported for very heavy nuclei with Z{sub C} > 90. The long time-scale of fission can be described in a model of 'fission by diffusion' that includes an assumption of the overdamped diabatic motion. The fission-to-spallation ratio at intermediate proton energy could be influenced by the viscosity, as well. Within a novel approach of the present work, the cross examination of the fission probability, time-scales, and pre-fission neutron multiplicities is resulted in the consistent interpretation of a whole set of the observables. Earlier, different aspects could be reproduced in partial simulations without careful coordination.

  18. Realistic fission model and the r-process in neutron star mergers

    SciTech Connect (OSTI)

    Shibagaki, S.; Kajino, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8850 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556, U.S.A. and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2014-05-09T23:59:59.000Z

    About half of heavy elements are considered to be produced by the rapid neutron-capture process, r-process. The neutron star merger is one of the viable candidates for the astrophysical site of r-process nucleosynthesis. Nuclear fission reactions play an important role in the r-process of neutron star mergers. However theoretical predictions about fission properties of neutron-rich nuclei have some uncertainties. Especially, their fission fragment distributions are totally unknown and the phenomenologically extrapolated distribution was often applied to nucleosynthesis calculations. In this study, we have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions. We discuss the effects on the r-process in neutron star mergers from the nuclear fission of heavy neutron-rich actinide elements. We also discuss how variations in the fission fragment distributions affect the abundance pattern.

  19. Uncertainties analysis of fission fraction for reactor antineutrino experiments using DRAGON

    E-Print Network [OSTI]

    X. B. Ma; L. Z. Wang; Y. X. Chen; W. L. Zhong; F. P. An

    2014-05-27T23:59:59.000Z

    Rising interest in nuclear reactors as a source of antineutrinos for experiments motivates validated, fast, and accessible simulation to predict reactor rates. First, DRAGON was developed to calculate the fission rates of the four most important isotopes in fissions,235U,238U,239Pu and141Pu, and it was validated for PWRs using the Takahama benchmark. The fission fraction calculation function was validated through comparing our calculation results with MIT's results. we calculate the fission fraction of the Daya Bay reactor core, and compare its with those calculated by the commercial reactor simulation program SCIENCE, which is used by the Daya Bay nuclear power plant, and the results was consist with each other. The uncertainty of the antineutrino flux by the fission fraction was studied, and the uncertainty of the antineutrino flux by the fission fraction simulation is 0.6% per core for Daya Bay antineutrino experiment.

  20. An evaporation-based model of thermal neutron induced ternary fission of plutonium

    E-Print Network [OSTI]

    J. P. Lestone

    2007-03-10T23:59:59.000Z

    Ternary fission probabilities for thermal neutron induced fission of plutonium are analyzed within the framework of an evaporation-based model where the complexity of time-varying potentials, associated with the neck collapse, are included in a simplistic fashion. If the nuclear temperature at scission and the fission-neck-collapse time are assumed to be ~1.2 MeV and ~10^-22 s, respectively, then calculated relative probabilities of ternary-fission light-charged-particle emission follow the trends seen in the experimental data. The ability of this model to reproduce ternary fission probabilities spanning seven orders of magnitude for a wide range of light-particle charges and masses implies that ternary fission is caused by the coupling of an evaporation-like process with the rapid re-arrangement of the nuclear fluid following scission.

  1. An evaporation-based model of thermal neutron induced ternary fission of plutonium

    E-Print Network [OSTI]

    Lestone, J P

    2007-01-01T23:59:59.000Z

    Ternary fission probabilities for thermal neutron induced fission of plutonium are analyzed within the framework of an evaporation-based model where the complexity of time-varying potentials, associated with the neck collapse, are included in a simplistic fashion. If the nuclear temperature at scission and the fission-neck-collapse time are assumed to be ~1.2 MeV and ~10^-22 s, respectively, then calculated relative probabilities of ternary-fission light-charged-particle emission follow the trends seen in the experimental data. The ability of this model to reproduce ternary fission probabilities spanning seven orders of magnitude for a wide range of light-particle charges and masses implies that ternary fission is caused by the coupling of an evaporation-like process with the rapid re-arrangement of the nuclear fluid following scission.

  2. Neutron-flux profile monitor for use in a fission reactor

    DOE Patents [OSTI]

    Kopp, M.K.; Valentine, K.H.

    1981-09-15T23:59:59.000Z

    A neutron flux monitor is provided which consists of a plurality of fission counters arranged as spaced-apart point detectors along a delay line. As a fission event occurs in any one of the counters, two delayed current pulses are generated at the output of the delay line. The time separation of the pulses identifies the counter in which the particular fission event occurred. Neutron flux profiles of reactor cores can be more accurately measured as a result.

  3. Assessment of fission product yields data needs in nuclear reactor applications

    SciTech Connect (OSTI)

    Kern, K.; Becker, M.; Broeders, C. [Institut fuer Neutronenphysik und Reaktortechnik, KIT Campus Nord, Hermann-von-Helmholtz-Platz 1, 76344 Leopoldshafen (Germany)

    2012-07-01T23:59:59.000Z

    Studies on the build-up of fission products in fast reactors have been performed, with particular emphasis on the effects related to the physics of the nuclear fission process. Fission product yields, which are required for burn-up calculations, depend on the proton and neutron number of the target nucleus as well as on the incident neutron energy. Evaluated nuclear data on fission product yields are available for all relevant target nuclides in reactor applications. However, the description of their energy dependence in evaluated data is still rather rudimentary, which is due to the lack of experimental fast fission data and reliable physical models. Additionally, physics studies of evaluated JEFF-3.1.1 fission yields data have shown potential improvements, especially for various fast fission data sets of this evaluation. In recent years, important progress in the understanding of the fission process has been made, and advanced model codes are currently being developed. This paper deals with the semi-empirical approach to the description of the fission process, which is used in the GEF code being developed by K.-H. Schmidt and B. Jurado on behalf of the OECD Nuclear Energy Agency, and with results from the corresponding author's diploma thesis. An extended version of the GEF code, supporting the calculation of spectrum weighted fission product yields, has been developed. It has been applied to the calculation of fission product yields in the fission rate spectra of a MOX fuelled sodium-cooled fast reactor. Important results are compared to JEFF-3.1.1 data and discussed in this paper. (authors)

  4. FREYA-a new Monte Carlo code for improved modeling of fission chains

    SciTech Connect (OSTI)

    Hagmann, C A; Randrup, J; Vogt, R L

    2012-06-12T23:59:59.000Z

    A new simulation capability for modeling of individual fission events and chains and the transport of fission products in materials is presented. FREYA ( Fission Yield Event Yield Algorithm ) is a Monte Carlo code for generating fission events providing correlated kinematic information for prompt neutrons, gammas, and fragments. As a standalone code, FREYA calculates quantities such as multiplicity-energy, angular, and gamma-neutron energy sharing correlations. To study materials with multiplication, shielding effects, and detectors, we have integrated FREYA into the general purpose Monte Carlo code MCNP. This new tool will allow more accurate modeling of detector responses including correlations and the development of SNM detectors with increased sensitivity.

  5. Event-by-event study of neutron observables in spontaneous and thermal fission

    SciTech Connect (OSTI)

    Vogt, R; Randrup, J

    2011-09-14T23:59:59.000Z

    The event-by-event fission model FREYA is extended to spontaneous fission of actinides and a variety of neutron observables are studied for spontaneous fission and fission induced by thermal neutrons with a view towards possible applications for SNM detection. We have shown that event-by-event models of fission, such as FREYA, provide a powerful tool for studying fission neutron correlations. Our results demonstrate that these correlations are significant and exhibit a dependence on the fissioning nucleus. Since our method is phenomenological in nature, good input data are especially important. Some of the measurements employed in FREYA are rather old and statistics limited. It would be useful to repeat some of these studies with modern detector techniques. In addition, most experiments made to date have not made simultaneous measurements of the fission products and the prompt observables, such as neutron and photons. Such data, while obviously more challenging to obtain, would be valuable for achieving a more complete understanding of the fission process.

  6. The Majorana Parts Tracking Database

    E-Print Network [OSTI]

    Abgrall, N; Avignone, F T; Bertrand, F E; Brudanin, V; Busch, M; Byram, D; Caldwell, A S; Chan, Y-D; Christofferson, C D; Combs, D C; Cuesta, C; Detwiler, J A; Doe, P J; Efremenko, Yu; Egorov, V; Ejiri, H; Elliott, S R; Esterline, J; Fast, J E; Finnerty, P; Fraenkle, F M; Galindo-Uribarri, A; Giovanetti, G K; Goett, J; Green, M P; Gruszko, J; Guiseppe, V E; Gusev, K; Hallin, A L; Hazama, R; Hegai, A; Henning, R; Hoppe, E W; Howard, S; Howe, M A; Keeter, K J; Kidd, M F; Kochetov, O; Kouzes, R T; LaFerriere, B D; Leon, J Diaz; Leviner, L E; Loach, J C; MacMullin, J; Martin, R D; Meijer, S J; Mertens, S; Miller, M L; Mizouni, L; Nomachi, M; Orrell, J L; O'Shaughnessy, C; Overman, N R; Petersburg, R; Phillips, D G; Poon, A W P; Pushkin, K; Radford, D C; Rager, J; Rielage, K; Robertson, R G H; Romero-Romero, E; Ronquest, M C; Shanks, B; Shima, T; Shirchenko, M; Snavely, K J; Snyder, N; Soin, A; Suriano, A M; Tedeschi, D; Thompson, J; Timkin, V; Tornow, W; Trimble, J E; Varner, R L; Vasilyev, S; Vetter, K; Vorren, K; White, B R; Wilkerson, J F; Wiseman, C; Xu, W; Yakushev, E; Young, A R; Yu, C -H; Zhitnikov, I

    2015-01-01T23:59:59.000Z

    The Majorana Demonstrator is an ultra-low background physics experiment searching for the neutrinoless double beta decay of $^{76}$Ge. The Majorana Parts Tracking Database is used to record the history of components used in the construction of the Demonstrator. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. A web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.

  7. The Majorana Parts Tracking Database

    E-Print Network [OSTI]

    The Majorana Collaboration; N. Abgrall; E. Aguayo; F. T. Avignone III; A. S. Barabash; F. E. Bertrand; V. Brudanin; M. Busch; D. Byram; A. S. Caldwell; Y-D. Chan; C. D. Christofferson; D. C. Combs; C. Cuesta; J. A. Detwiler; P. J. Doe; Yu. Efremenko; V. Egorov; H. Ejiri; S. R. Elliott; J. Esterline; J. E. Fast; P. Finnerty; F. M. Fraenkle; A. Galindo-Uribarri; G. K. Giovanetti; J. Goett; M. P. Green; J. Gruszko; V. E. Guiseppe; K. Gusev; A. L. Hallin; R. Hazama; A. Hegai; R. Henning; E. W. Hoppe; S. Howard; M. A. Howe; K. J. Keeter; M. F. Kidd; O. Kochetov; S. I. Konovalov; R. T. Kouzes; B. D. LaFerriere; J. Diaz Leon; L. E. Leviner; J. C. Loach; J. MacMullin; R. D. Martin; S. J. Meijer; S. Mertens; M. L. Miller; L. Mizouni; M. Nomachi; J. L. Orrell; C. O'Shaughnessy; N. R. Overman; R. Petersburg; D. G. Phillips II; A. W. P. Poon; K. Pushkin; D. C. Radford; J. Rager; K. Rielage; R. G. H. Robertson; E. Romero-Romero; M. C. Ronquest; B. Shanks; T. Shima; M. Shirchenko; K. J. Snavely; N. Snyder; A. Soin; A. M. Suriano; D. Tedeschi; J. Thompson; V. Timkin; W. Tornow; J. E. Trimble; R. L. Varner; S. Vasilyev; K. Vetter; K. Vorren; B. R. White; J. F. Wilkerson; C. Wiseman; W. Xu; E. Yakushev; A. R. Young; C. -H. Yu; V. Yumatov; I. Zhitnikov

    2015-02-05T23:59:59.000Z

    The Majorana Demonstrator is an ultra-low background physics experiment searching for the neutrinoless double beta decay of $^{76}$Ge. The Majorana Parts Tracking Database is used to record the history of components used in the construction of the Demonstrator. The tracking implementation takes a novel approach based on the schema-free database technology CouchDB. Transportation, storage, and processes undergone by parts such as machining or cleaning are linked to part records. Tracking parts provides a great logistics benefit and an important quality assurance reference during construction. In addition, the location history of parts provides an estimate of their exposure to cosmic radiation. A web application for data entry and a radiation exposure calculator have been developed as tools for achieving the extreme radio-purity required for this rare decay search.

  8. Analysis of Fission Products on the AGR-1 Capsule Components

    SciTech Connect (OSTI)

    Paul A. Demkowicz; Jason M. Harp; Philip L. Winston; Scott A. Ploger

    2013-03-01T23:59:59.000Z

    The components of the AGR-1 irradiation capsules were analyzed to determine the retained inventory of fission products in order to determine the extent of in-pile fission product release from the fuel compacts. This includes analysis of (i) the metal capsule components, (ii) the graphite fuel holders, (iii) the graphite spacers, and (iv) the gas exit lines. The fission products most prevalent in the components were Ag-110m, Cs 134, Cs 137, Eu-154, and Sr 90, and the most common location was the metal capsule components and the graphite fuel holders. Gamma scanning of the graphite fuel holders was also performed to determine spatial distribution of Ag-110m and radiocesium. Silver was released from the fuel components in significant fractions. The total Ag-110m inventory found in the capsules ranged from 1.2×10 2 (Capsule 3) to 3.8×10 1 (Capsule 6). Ag-110m was not distributed evenly in the graphite fuel holders, but tended to concentrate at the axial ends of the graphite holders in Capsules 1 and 6 (located at the top and bottom of the test train) and near the axial center in Capsules 2, 3, and 5 (in the center of the test train). The Ag-110m further tended to be concentrated around fuel stacks 1 and 3, the two stacks facing the ATR reactor core and location of higher burnup, neutron fluence, and temperatures compared with Stack 2. Detailed correlation of silver release with fuel type and irradiation temperatures is problematic at the capsule level due to the large range of temperatures experienced by individual fuel compacts in each capsule. A comprehensive Ag 110m mass balance for the capsules was performed using measured inventories of individual compacts and the inventory on the capsule components. For most capsules, the mass balance was within 11% of the predicted inventory. The Ag-110m release from individual compacts often exhibited a very large range within a particular capsule.

  9. Robotic vehicle with multiple tracked mobility platforms

    DOE Patents [OSTI]

    Salton, Jonathan R. (Albuquerque, NM); Buttz, James H. (Albuquerque, NM); Garretson, Justin (Albuquerque, NM); Hayward, David R. (Wetmore, CO); Hobart, Clinton G. (Albuquerque, NM); Deuel, Jr., Jamieson K. (Albuquerque, NM)

    2012-07-24T23:59:59.000Z

    A robotic vehicle having two or more tracked mobility platforms that are mechanically linked together with a two-dimensional coupling, thereby forming a composite vehicle of increased mobility. The robotic vehicle is operative in hazardous environments and can be capable of semi-submersible operation. The robotic vehicle is capable of remote controlled operation via radio frequency and/or fiber optic communication link to a remote operator control unit. The tracks have a plurality of track-edge scallop cut-outs that allow the tracks to easily grab onto and roll across railroad tracks, especially when crossing the railroad tracks at an oblique angle.

  10. Tracking the Elusive QOOH Radical

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2, 2003Tool ofTopo II:7.1Tracking Living CellsTracking

  11. Tracking the Elusive QOOH Radical

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesisAppliances » TopTours SignTracking LivingTracking

  12. Fission involves a new state of nuclear matter

    E-Print Network [OSTI]

    C. Ythier; S. Hachem; G. Mouze

    2011-01-10T23:59:59.000Z

    The rearrangement step of nuclear fission occurs within 0.17 yoctosecond, in a new state of nuclear matter characterized by the formation of closed shells of nucleons. The determination of its lifetime is now based on the prompt neutron emission law. The width of isotopic distributions measures the uncertainty in the neutron number of the fragments. Magic mass numbers, 82 and 126, play a major role in the mass distributions. Arguments are presented in favour of an all-neutron state. The boson field responsible for the new collective interaction has to be searched for.

  13. Cryogenic method for measuring nuclides and fission gases

    DOE Patents [OSTI]

    Perdue, P.T.; Haywood, F.F.

    1980-05-02T23:59:59.000Z

    A cryogenic method is provided for determining airborne gases and particulates from which gamma rays are emitted. A special dewar counting vessel is filled with the contents of the sampling flask which is immersed in liquid nitrogen. A vertically placed sodium-iodide or germanium-lithium gamma-ray detector is used. The device and method are of particular use in measuring and identifying the radioactive noble gases including emissions from coal-fired power plants, as well as fission gases released or escaping from nuclear power plants.

  14. Radiolysis Concerns for Water Shielding in Fission Surface Power Applications

    SciTech Connect (OSTI)

    Schoenfeld, Michael P. [NASA Marshall Space Flight Center, ER24, MSFC, AL 35812 (United States); Anghaie, Samim [Innovative Space Power and Propulsion Institute, 800 SW Archer Rd. Bldg.554, P.O. Box 116502, University of Florida, Gainesville, FL 32611-6502 (United States)

    2008-01-21T23:59:59.000Z

    This paper presents an overview of radiolysis concerns with regard to water shields for fission surface power. A review of the radiolysis process is presented and key parameters and trends are identified. From this understanding of the radiolytic decomposition of water, shield pressurization and corrosion are identified as the primary concerns. Existing experimental and modeling data addressing concerns are summarized. It was found that radiolysis of pure water in a closed volume results in minimal, if any net decomposition, and therefore reduces the potential for shield pressurization and corrosion.

  15. Fission meter and neutron detection using poisson distribution comparison

    DOE Patents [OSTI]

    Rowland, Mark S; Snyderman, Neal J

    2014-11-18T23:59:59.000Z

    A neutron detector system and method for discriminating fissile material from non-fissile material wherein a digital data acquisition unit collects data at high rate, and in real-time processes large volumes of data directly into information that a first responder can use to discriminate materials. The system comprises counting neutrons from the unknown source and detecting excess grouped neutrons to identify fission in the unknown source. Comparison of the observed neutron count distribution with a Poisson distribution is performed to distinguish fissile material from non-fissile material.

  16. NEET Micro-Pocket Fission Detector -- FY 2012 Status Report

    SciTech Connect (OSTI)

    Troy Unruh; Joy Rempe; Douglas McGregor; Philip Ugorowski; Michael Reichenberger

    2012-09-01T23:59:59.000Z

    A research program has been initiated by the NEET program for developing and testing compact miniature fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package. When implemented, these sensors will significantly advance flux detection capabilities for irradiation tests in US Materials Test Reactors (MTRs).Ultimately, evaluations may lead to a more compact, more accurate, and longer lifetime flux sensor for critical mock-ups, high performance reactors and commercial nuclear power plants. Deployment of Micro-Pocket Fission Detectors (MPFDs) in US DOE-NE program irradiation tests will address several challenges: Current fission chamber technologies do not offer the ability to measure fast flux, thermal flux and temperature within a single compact probe, MPFDs offer this option. MPFD construction is very different then current fission chamber construction; the use of high temperature materials allow MPFDs to be specifically tailored to survive harsh conditions in typical high performance MTR irradiation tests. New high-fidelity reactor physics codes will need a small, accurate, multipurpose in-core sensor to validate the codes without perturbing the validation experiment; MPFDs fill this requirement. MPFDs can be built with variable sensitivities to survive the lifetime of an experiment or fuel assembly in some MTRs; allowing for more efficient and cost effective power monitoring. The small size of the MPFDs allows multiple sensors to be simultaneously deployed; obtaining data required to visualize the reactor flux and temperature profiles. This report summarizes the research progress for year 1 of this 3 year project. An updated design of the MPFD has been developed, materials and tools to support the new design have been procured, construction methods to support the new design have been initiated at INL’s HTTL and KSU’s SMART Laboratory, plating methods are being updated at KSU, new detector electronics have been designed, built and tested at KSU. In addition, a project meeting was held at KSU and a detector evaluation plan has been initiated between INL and KSU. Once NEET program evaluations are completed, the final MPFD will be deployed in MTR irradiations, enabling DOE-NE programs evaluating the performance of candidate new fuels and materials to better characterize irradiation test conditions.

  17. NEET Micro-Pocket Fission Detector – Final Project report

    SciTech Connect (OSTI)

    Joy Rempe; Douglas McGregor; Philip Ugorowski; Michael Reichenberger; Takashi Ito

    2014-09-01T23:59:59.000Z

    A collaboration between the Idaho National Laboratory (INL), the Kansas State University (KSU), and the French Alternative Energies and Atomic Energy Commission, Commissariat à l'Énergie Atomique et aux Energies Alternatives, (CEA), is fundedby the Nuclear Energy Enabling Technologies (NEET) program to develop and test Micro-Pocket Fission Detectors (MPFDs), which are compact fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package. When deployed, these sensors will significantly advance flux detection capabilities for irradiation tests in US Material Test Reactors (MTRs). Ultimately, evaluations may lead to a more compact, more accurate, and longer lifetime flux sensor for critical mock-ups, and high performance reactors, allowing several Department of Energy Office of Nuclear Energy (DOE-NE) programs to obtain higher accuracy/higher resolution data from irradiation tests of candidate new fuels and materials. Specifically, deployment of MPFDs will address several challenges faced in irradiations performed at MTRs: • Current fission chamber technologies do not offer the ability to measure fast flux, thermal flux and temperature within a single compact probe; MPFDs offer this option. • MPFD construction is very different than current fission chamber construction; the use of high temperature materials allow MPFDs to be specifically tailored to survive harsh conditions encountered in-core of high performance MTRs. • The higher accuracy, high fidelity data available from the compact MPFD will significantly enhance efforts to validate new high-fidelity reactor physics codes and new multi-scale, multi-physics codes. • MPFDs can be built with variable sensitivities to survive the lifetime of an experiment or fuel assembly in some MTRs, allowing for more efficient and cost effective power monitoring. • The small size of the MPFDs allows multiple sensors to be deployed, offering the potential to accurately measure the flux and temperature profiles in the reactor. This report summarizes the status at the end of year two of this three year project. As documented in this report, all planned accomplishments for developing this unique new, compact, multipurpose sensor have been completed.

  18. Singlet Fission | MIT-Harvard Center for Excitonics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebookScholarship Fund3 Outlook for GulfSimulationsApplications |Fission

  19. A fission-fusion hybrid reactor in steady-state L-mode tokamak configuration with natural uranium

    E-Print Network [OSTI]

    Reed, Mark Wilbert

    2011-01-01T23:59:59.000Z

    The most prevalent criticism of fission-fusion hybrids is simply that they are too exotic - that they would exacerbate the challenges of both fission and fusion. This is not really true. Intriguingly, hybrids could actually ...

  20. A scoping study of fission product transport from failed fuel during N Reactor postulated accidents

    SciTech Connect (OSTI)

    Hagrman, D.L.

    1988-01-01T23:59:59.000Z

    This report presents a scoping study of cesium, iodine, and tellurium behavior during a cold leg manifold break in the N Reactor. More detail about fission product behavior than has previously been available is provided and key parameters that control this behavior are identified. The LACE LA1 test and evidence from the Power Burst Facility Severe Fuel Damage tests are used to test the key model applied to determine aerosol behavior. Recommendations for future analysis are also provided. The primary result is that most of the cesium, iodine, and tellurium remains in the molten uranium fuel. Only 0.0035 of the total inventory is calculated to be released. Condensation of the most of the species of cesium and iodine that are released is calculated, with 0.998 of the released cesium and iodine condensing in the spacers and upstream end of the connector tubes. Most of the tellurium that is released condenses, but the chemical reaction of tellurium vapor with surfaces is also a major factor in the behavior of this element.

  1. Social Group Fission and the Origin of Intergroup Genetic Differentiation among the Rhesus

    E-Print Network [OSTI]

    Cheverud, James M.

    Group L's eight years prior to being bled while the matrilineages of Groups I and F split approximatelySocial Group Fission and the Origin of Intergroup Genetic Differentiation among the Rhesus Monkeys,y, New York, KEY WORDS ferrin . Group fission . Genetic differentiation Macaca mulatta . Cay0 Santiago

  2. Vol. 6 (2013) Acta Physica Polonica B Proceedings Supplement No 4 NUCLEAR FISSION WITHIN

    E-Print Network [OSTI]

    Pomorski, Krzysztof

    2013-01-01T23:59:59.000Z

    Vol. 6 (2013) Acta Physica Polonica B Proceedings Supplement No 4 NUCLEAR FISSION WITHIN THE LUBLIN to the description of the nuclear bind- ing energies and the fission barriers (for review, see [10]). Nevertheless, 2013) A review of applications of the nuclear Lublin­Strasbourg Drop (LSD) model to evaluation

  3. Report on Fission Time Projection Chamber M3FT-12IN0210052

    SciTech Connect (OSTI)

    James K. Jewell

    2012-08-01T23:59:59.000Z

    The Time Projection Chamber is a collaborative effort to implement an innovative approach and deliver unprecedented fission measurements to DOE programs. This 4?-detector system will provide unrivaled 3-D data about the fission process. Shown here is a half populated TPC (2?) at the LLNL TPC laboratory as it undergoes testing before being shipped to LANSCE for beam experiments.

  4. Effects of Nuclear Structure on Quasi-fission C. Simenel,1, 2,

    E-Print Network [OSTI]

    Boyer, Edmond

    Effects of Nuclear Structure on Quasi-fission C. Simenel,1, 2, A. Wakhle,2 B. Avez,3,1 D. J. Hinde/Service de Physique Nucl´eaire, F-91191 Gif-sur-Yvette, France 2 Department of Nuclear Physics, Research Solarium, BP120, 33175 Gradignan, France The quasi-fission mechanism hinders fusion of heavy systems

  5. Euratom Programme for Nuclear Research and Training FP7-Fission-2008 GUIDE FOR APPLICANTS

    E-Print Network [OSTI]

    De Cindio, Fiorella

    Euratom Programme for Nuclear Research and Training FP7-Fission-2008 1 GUIDE FOR APPLICANTS All Programme for Nuclear Research and Training FP7-Fission-2008 2 About this Guide This is version 3 (dated 20 funding schemes Euratom Programme for Nuclear Research and Training Activities Call Identifier: FP7

  6. LES NEUTRONS DE FISSION ET LA RACTION EN CHAINE Par L. KOWARSKI.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    neutrons lors de la fission de l'uranium (Collège de France, mars1939, et Columbia University), à la, dont l'exploration fut la première étape dans la marche vers la conquête de l'énergie 'atomique. C et complétée par Frisch et Joliot, de la fission de l'uranium. Cette réaction, exothermique à un

  7. Time evolution of the fission-decay width under the influence of dissipation

    E-Print Network [OSTI]

    B. Jurado; K. -H. Schmidt; J. Benlliure

    2002-12-18T23:59:59.000Z

    Different analytical approximations to the time-dependent fission-decay width used to extract the influence of dissipation on the fission process are critically examined. Calculations with a new, highly realistic analytical approximation to the exact solution of the Fokker-Planck equation sheds doubts on previous conclusions on the dissipation strength made on the basis of less realistic approximations.

  8. Resonant tunneling and the bimodal symmetric fission of sup 258 Fm

    SciTech Connect (OSTI)

    Bhandari, B.S. (Department of Physics, Faculty of Science, University of Garyounis, Benghazi, Libya (LY))

    1991-02-25T23:59:59.000Z

    The concept of resonant tunneling is invoked to explain the sharp drop in the measured spontaneous-fission half-life when going from {sup 256}Fm to {sup 258}Fm. Various consequences of such a suggestion on the other observed characteristics of the bimodal symmetric fission of {sup 258}Fm are briefly discussed.

  9. Quantum and Thermodynamic Properties of Spontaneous and Low-Energy Induced Fission of Nuclei

    SciTech Connect (OSTI)

    Kadmensky, S.G. [Voronezh State University, Universitetskaya pl. 1, Voronezh, 394693 (Russian Federation)

    2005-12-01T23:59:59.000Z

    It is shown that A. Bohr's concept of transition fission states can be matched with the properties of Coriolis interaction if an axisymmetric fissile nucleus near the scission point remains cold despite a nonadiabatic character of nuclear collective deformation motion. The quantum and thermodynamic properties of various stages of binary and ternary fission after the descent of a fissile nucleus from the outer saddle point are studied within quantum-mechanical fission theory. It is shown that two-particle nucleon-nucleon correlations--in particular, superfluid correlations--play an important role in the formation of fission products and in the classification of fission transitions. The distributions of thermalized primary fission fragments with respect to spins and their projections onto the symmetry axis of the fissile nucleus and fission fragments are constructed, these distributions determining the properties of prompt neutrons and gamma rays emitted by these fragments. A new nonevaporation mechanism of third-particle production in ternary fission is proposed. This mechanism involves transitions of third particles from the cluster states of the fissile-nucleus neck to high-energy states under effects of the shake-off type that are due to the nonadiabatic character of nuclear collective deformation motion.

  10. Measurement and Analysis of Fission Rates in a Spherical Mockup of Uranium and Polyethylene

    E-Print Network [OSTI]

    Tong-Hua, Zhu; Xin-Xin, Lu; Rong, Liu; Zi-Jie, Han; Li, Jiang; Mei, Wang

    2013-01-01T23:59:59.000Z

    Measurements of the reaction rate distribution were carried out using two kinds of Plate Micro Fission Chamber(PMFC). The first is a depleted uranium chamber and the second an enriched uranium chamber. The material in the depleted uranium chamber is strictly the same as the material in the uranium assembly. With the equation solution to conduct the isotope contribution correction, the fission rate of 238U and 235U were obtained from the fission rate of depleted uranium and enriched uranium. And then, the fission count of 238U and 235U in an individual uranium shell was obtained. In this work, MCNP5 and continuous energy cross sections ENDF/BV.0 were used for the analysis of fission rate distribution and fission count. The calculated results were compared with the experimental ones. The calculation of fission rate of DU and EU were found to agree with the measured ones within 10% except at the positions in polyethylene region and the two positions near the outer surface. Beacause the fission chamber was not co...

  11. AGATA - Advanced Gamma Tracking Array

    E-Print Network [OSTI]

    S. Akkoyun; A. Algora; B. Alikhani; F. Ameil; G. de Angelis; L. Arnold; A. Astier; A. Ataç; Y. Aubert; C. Aufranc; A. Austin; S. Aydin; F. Azaiez; S. Badoer; D. L. Balabanski; D. Barrientos; G. Baulieu; R. Baumann; D. Bazzacco; F. A. Beck; T. Beck; P. Bednarczyk; M. Bellato; M. A. Bentley; G. Benzoni; R. Berthier; L. Berti; R. Beunard; G. Lo Bianco; B. Birkenbach; P. G. Bizzeti; A. M. Bizzeti-Sona; F. Le Blanc; J. M. Blasco; N. Blasi; D. Bloor; C. Boiano; M. Borsato; D. Bortolato; A. J. Boston; H. C. Boston; P. Bourgault; P. Boutachkov; A. Bouty; A. Bracco; S. Brambilla; I. P. Brawn; A. Brondi; S. Broussard; B. Bruyneel; D. Bucurescu; I. Burrows; A. Bürger; S. Cabaret; B. Cahan; E. Calore; F. Camera; A. Capsoni; F. Carrió; G. Casati; M. Castoldi; B. Cederwall; J. -L. Cercus; V. Chambert; M. El Chambit; R. Chapman; L. Charles; J. Chavas; E. Clément; P. Cocconi; S. Coelli; P. J. Coleman-Smith; A. Colombo; S. Colosimo; C. Commeaux; D. Conventi; R. J. Cooper; A. Corsi; A. Cortesi; L. Costa; F. C. L. Crespi; J. R. Cresswell; D. M. Cullen; D. Curien; A. Czermak; D. Delbourg; R. Depalo; T. Descombes; P. Désesquelles; P. Detistov; C. Diarra; F. Didierjean; M. R. Dimmock; Q. T. Doan; C. Domingo-Pardo; M. Doncel; F. Dorangeville; N. Dosme; Y. Drouen; G. Duchêne; B. Dulny; J. Eberth; P. Edelbruck; J. Egea; T. Engert; M. N. Erduran; S. Ertürk; C. Fanin; S. Fantinel; E. Farnea; T. Faul; M. Filliger; F. Filmer; Ch. Finck; G. de France; A. Gadea; W. Gast; A. Geraci; J. Gerl; R. Gernhäuser; A. Giannatiempo; A. Giaz; L. Gibelin; A. Givechev; N. Goel; V. González; A. Gottardo; X. Grave; J. Gr?bosz; R. Griffiths; A. N. Grint; P. Gros; L. Guevara; M. Gulmini; A. Görgen; H. T. M. Ha; T. Habermann; L. J. Harkness; H. Harroch; K. Hauschild; C. He; A. Hernández-Prieto; B. Hervieu; H. Hess; T. Hüyük; E. Ince; R. Isocrate; G. Jaworski; A. Johnson; J. Jolie; P. Jones; B. Jonson; P. Joshi; D. S. Judson; A. Jungclaus; M. Kaci; N. Karkour; M. Karolak; A. Ka?ka?; M. Kebbiri; R. S. Kempley; A. Khaplanov; S. Klupp; M. Kogimtzis; I. Kojouharov; A. Korichi; W. Korten; Th. Kröll; R. Krücken; N. Kurz; B. Y. Ky; M. Labiche; X. Lafay; L. Lavergne; I. H. Lazarus; S. Leboutelier; F. Lefebvre; E. Legay; L. Legeard; F. Lelli; S. M. Lenzi; S. Leoni; A. Lermitage; D. Lersch; J. Leske; S. C. Letts; S. Lhenoret; R. M. Lieder; D. Linget; J. Ljungvall; A. Lopez-Martens; A. Lotodé; S. Lunardi; A. Maj; J. van der Marel; Y. Mariette; N. Marginean; R. Marginean; G. Maron; A. R. Mather; W. M?czy?ski; V. Mendéz; P. Medina; B. Melon; R. Menegazzo; D. Mengoni; E. Merchan; L. Mihailescu; C. Michelagnoli; J. Mierzejewski; L. Milechina; B. Million; K. Mitev; P. Molini; D. Montanari; S. Moon; F. Morbiducci; R. Moro; P. S. Morrall; O. Möller; A. Nannini; D. R. Napoli; L. Nelson; M. Nespolo; V. L. Ngo; M. Nicoletto; R. Nicolini; Y. Le Noa; P. J. Nolan; M. Norman; J. Nyberg; A. Obertelli; A. Olariu; R. Orlandi; D. C. Oxley; C. Özben; M. Ozille; C. Oziol; E. Pachoud; M. Palacz; J. Palin; J. Pancin; C. Parisel; P. Pariset; G. Pascovici; R. Peghin; L. Pellegri; A. Perego; S. Perrier; M. Petcu; P. Petkov; C. Petrache; E. Pierre; N. Pietralla; S. Pietri; M. Pignanelli; I. Piqueras; Z. Podolyak; P. Le Pouhalec; J. Pouthas; D. Pugnére; V. F. E. Pucknell; A. Pullia; B. Quintana; R. Raine; G. Rainovski; L. Ramina; G. Rampazzo; G. La Rana; M. Rebeschini; F. Recchia; N. Redon; M. Reese; P. Reiter; P. H. Regan; S. Riboldi; M. Richer; M. Rigato; S. Rigby; G. Ripamonti; A. P. Robinson; J. Robin; J. Roccaz; J. -A. Ropert; B. Rossé; C. Rossi Alvarez; D. Rosso; B. Rubio; D. Rudolph; F. Saillant; E. ?ahin; F. Salomon; M. -D. Salsac; J. Salt; G. Salvato; J. Sampson; E. Sanchis; C. Santos; H. Schaffner; M. Schlarb; D. P. Scraggs; D. Seddon; M. ?enyi?it; M. -H. Sigward; G. Simpson; J. Simpson; M. Slee; J. F. Smith; P. Sona; B. Sowicki; P. Spolaore; C. Stahl; T. Stanios; E. Stefanova; O. Stézowski; J. Strachan; G. Suliman; P. -A. Söderström; J. L. Tain; S. Tanguy; S. Tashenov; Ch. Theisen; J. Thornhill; F. Tomasi; N. Toniolo; R. Touzery; B. Travers; A. Triossi; M. Tripon; K. M. M. Tun-Lanoë; M. Turcato; C. Unsworth; C. A. Ur; J. J. Valiente-Dobon; V. Vandone; E. Vardaci; R. Venturelli; F. Veronese; Ch. Veyssiere; E. Viscione; R. Wadsworth; P. M. Walker; N. Warr; C. Weber; D. Weisshaar; D. Wells; O. Wieland; A. Wiens; G. Wittwer; H. J. Wollersheim; F. Zocca; N. V. Zamfir; M. Zi?bli?ski; A. Zucchiatti

    2012-09-17T23:59:59.000Z

    The Advanced GAmma Tracking Array (AGATA) is a European project to develop and operate the next generation gamma-ray spectrometer. AGATA is based on the technique of gamma-ray energy tracking in electrically segmented high-purity germanium crystals. This technique requires the accurate determination of the energy, time and position of every interaction as a gamma ray deposits its energy within the detector volume. Reconstruction of the full interaction path results in a detector with very high efficiency and excellent spectral response. The realization of gamma-ray tracking and AGATA is a result of many technical advances. These include the development of encapsulated highly-segmented germanium detectors assembled in a triple cluster detector cryostat, an electronics system with fast digital sampling and a data acquisition system to process the data at a high rate. The full characterization of the crystals was measured and compared with detector-response simulations. This enabled pulse-shape analysis algorithms, to extract energy, time and position, to be employed. In addition, tracking algorithms for event reconstruction were developed. The first phase of AGATA is now complete and operational in its first physics campaign. In the future AGATA will be moved between laboratories in Europe and operated in a series of campaigns to take advantage of the different beams and facilities available to maximize its science output. The paper reviews all the achievements made in the AGATA project including all the necessary infrastructure to operate and support the spectrometer.

  12. (COMEDIE program review and fission product transport in MHTGR reactor)

    SciTech Connect (OSTI)

    Stansfield, O.M.

    1990-03-15T23:59:59.000Z

    The subcontract between Martin Marietta Energy Systems, Inc., and the CEA provides for the refurbishment of the high pressure COMEDIE test loop in the SILOE reactor and a series of experiments to characterize fission product lift-off from MHTGR heat exchanger surfaces under several depressurization accident scenarios. The data will contribute to the validation of models and codes used to predict fission product transport in the MHTGR. In the meeting at CEA headquarters in Paris the program schedule and preparation for the DCAA and Quality Assurance audits were discussed. Long-range interest in expanded participation in the gas-cooled reactor technology Umbrella Agreement was also expressed by the CEA. At the CENG, in Grenoble, technical details on the loop design, fabrication components, development of test procedures, and preparation for the DOE quality assurance (QA) audit in May were discussed. After significant delays in CY 1989 it appears that good progress is being made in CY 1990 and the first major test will be initiated by December. An extensive list of agreements and commitments was generated to facilitate the coordination and planning of future work. 2 figs., 2 tabs.

  13. Active dipole clusters: from helical motion to fission

    E-Print Network [OSTI]

    Andreas Kaiser; Katarina Popowa; Hartmut Löwen

    2015-05-29T23:59:59.000Z

    The structure of a finite particle cluster is typically determined by total energy minimization. Here we consider the case where a cluster of soft sphere dipoles becomes active, i.e. when the individual particles exhibit an additional self-propulsion along their dipole moments. We numerically solve the overdamped equations of motion for soft-sphere dipoles in a solvent. Starting from an initial metastable dipolar cluster, the self-propulsion generates a complex cluster dynamics. The final cluster state has in general a structure widely different to the initial one, the details depend on the model parameters and on the protocol of how the self-propulsion is turned on. The center-of-mass of the cluster moves on a helical path, the details of which are governed by the initial cluster magnetization. An instantaneous switch to a high self-propulsion leads to fission of the cluster. However, fission does not occur if the self-propulsion is increased slowly to high strengths. Our predictions can be verified through experiments with self-phoretic colloidal Janus-particles and for macroscopic self-propelled dipoles in a highly viscous solvent.

  14. Tracking dynamic regions of texture and shape

    E-Print Network [OSTI]

    Migdal, Joshua N. (Joshua Nicholas), 1979-

    2007-01-01T23:59:59.000Z

    The tracking of visual phenomena is a problem of fundamental importance in computer vision. Tracks are used in many contexts, including object recognition, classification, camera calibration, and scene understanding. ...

  15. Childhood Cancer Tracking Initiative in Massachusetts

    E-Print Network [OSTI]

    Childhood Cancer Tracking Initiative in Massachusetts: Developing a New Electronic Tool Presented (CEH) Massachusetts Department of Public Health (MDPH) #12;Childhood Cancer Tracking Initiative "Develop methods for linking environmental databases with childhood cancer incidence data to identify

  16. Comparison of Current LCD Tracking Options

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Comparison of Current LCD Tracking Options Bruce Schumm Santa Cruz Institute for Particle Physics tracking somewhat more pressed for new S design (pattern recognition, ` resolution) S detector in real

  17. Complete and incomplete fusion competition in 11B-induced fission reaction on medium mass targets at intermediate energies

    E-Print Network [OSTI]

    Demekhina, N A; Balabekyan, A R

    2014-01-01T23:59:59.000Z

    The cross sections for the binary fission of 197Au, 181Ta and 209Bi targets induced by 11B ions were measured at intermediate energies. The fission products cross sections were studied by means of activation analysis in off-line regime observed gamma-ray spectra. The fission cross section is reconstructed on the basis of charge and mass distribution of the fission products.

  18. Complete and incomplete fusion competition in 11B-induced fission reaction on medium mass targets at intermediate energies

    E-Print Network [OSTI]

    N. A. Demekhina; G. S. Karapetyan; A. R. Balabekyan

    2014-12-22T23:59:59.000Z

    The cross sections for the binary fission of 197Au, 181Ta and 209Bi targets induced by 11B ions were measured at intermediate energies. The fission products cross sections were studied by means of activation analysis in off-line regime observed gamma-ray spectra. The fission cross section is reconstructed on the basis of charge and mass distribution of the fission products.

  19. Cross sections and barriers for nuclear fission induced by high-energy nucleons

    SciTech Connect (OSTI)

    Grudzevich, O. T., E-mail: ogrudzevich@ippe.ru [Leipunsky Institute for Physics and Power Engineering (Russian Federation); Yavshits, S. G. [Khlopin Radium Institute (Russian Federation)] [Khlopin Radium Institute (Russian Federation)

    2013-03-15T23:59:59.000Z

    The cross sections for the fission of {sup 232}Th, {sup 235,238}U, {sup 237}Np, and {sup 239}Pu target nuclei that was induced by 20- to 1000-MeV neutrons and protons were calculated. The respective calculations were based on the multiconfiguration-fission (MCFx) model, which was used to describe three basic stages of the interaction of high-energy nucleons with nuclei: direct processes (intranuclear cascade), equilibration of the emerging compound system, and the decay of the compound nucleus (statistical model). Fission barriers were calculated within the microscopic approach for isotopic chains formed by 15 to 20 nuclei of the required elements. The calculated fission cross sections were compared with available experimental data. It was shown that the input data set and the theoretical model used made it possible to predict satisfactorily cross section for nuclear fission induced by 20- to 1000-MeV nucleons.

  20. Radiation re-solution of fission gas in non-oxide nuclear fuel

    SciTech Connect (OSTI)

    Christopher Matthews; Daniel Schwen; Andrew C. Klein

    2014-12-01T23:59:59.000Z

    Renewed interest in fast nuclear reactors is creating a need for better understanding of fission gas bubble behavior in non-oxide fuels to support very long fuel lifetimes. Collisions between fission fragments and their subsequent cascades can knock fission gas atoms out of bubbles and back into the fuel lattice. We showed that these collisions can be treated as using the so-called ‘‘homogenous’’ atom-by-atom re-solution theory and calculated using the Binary Collision Approximation code 3DOT. The calculations showed that there is a decrease in the re-solution parameter as bubble radius increases until about 50 nm, at which the re-solution parameter stays nearly constant. Furthermore, our model shows ion cascades created in the fuel result in many more implanted fission gas atoms than collisions directly with fission fragments. This calculated re-solution parameter can be used to find a re-solution rate for future bubble simulations.

  1. P-odd and P-even correlations for third particles in ternary fission

    SciTech Connect (OSTI)

    Bunakov, V. E., E-mail: bunakov@vb13190.spbu.edu; Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V. [Russian Academy of Sciences, Petersburg Nuclear Physics Institute (Russian Federation)

    2008-12-15T23:59:59.000Z

    Within quantum-mechanical fission theory, P-odd and P-even correlations in angular distributions of products of the ternary fission of nuclei that is induced by polarized cold and thermal neutrons are investigated on the basis of a nonevaporative mechanism of third-particle emission and under the assumption that a two-humped fission barrier exists. It is shown that these correlations for third particles are induced by the analogous correlations for ternary-fission fragments, the latter being transferred to the third particle because of the kinematical conditions of third-particle emission that are associated with the charge and mass asymmetry of fragments. Optimum methods for observing the above correlations for third particles are discussed. The possibility of discovering the emission of prescission neutrons in the fission process against the background of evaporated neutrons by means of studying P-odd and P-even correlations is explored.

  2. Angular distribution of products of ternary nuclear fission induced by cold polarized neutrons

    SciTech Connect (OSTI)

    Bunakov, V. E., E-mail: bunakov@vb13190.spbu.edu; Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Kadmensky, S. S. [Voronezh State University (Russian Federation)

    2008-11-15T23:59:59.000Z

    Within quantum fission theory, angular distributions of products originating from the ternary fission of nuclei that is induced by polarized cold and thermal neutrons are investigated on the basis of a non-evaporative mechanism of third-particle emission and a consistent description of fission-channel coupling. It is shown that the inclusion of Coriolis interaction both in the region of the discrete and in the region of the continuous spectrum of states of the system undergoing fission leads to T-odd correlations in the aforementioned angular distributions. The properties of the TRI and ROT effects discovered recently, which are due to the interference between the fission amplitudes of neutron resonances, are explored. The results obtained here are compared with their counterparts from classic calculations based on the trajectory method.

  3. Track 5: Integration of Safety Into Design

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 5: Integration of Safety Into Design

  4. Track 6: Integrating Safety Into Security Operations

    Broader source: Energy.gov [DOE]

    ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 6: Integrating Safety Into Security Operations

  5. About the inconsistency between Bohr-Wheelers transition-state method and Kramers' escape rate in nuclear fission

    E-Print Network [OSTI]

    K. -H. Schmidt

    2008-10-30T23:59:59.000Z

    The problem of an apparent inconsistency between the fission rates derived on the basis of Bohr-Wheeler's transition-state method and Kramers' dynamical model of nuclear fission, first pointed out by Strutinsky in 1973, is revisited. The study is based on studying the features of individual trajectories on the fission path.

  6. Nuclear Instruments and Methods in Physics Research A 554 (2005) 340346 A compensated fission detector based on photovoltaic cells

    E-Print Network [OSTI]

    Danon, Yaron

    2005-01-01T23:59:59.000Z

    Nuclear Instruments and Methods in Physics Research A 554 (2005) 340­346 A compensated fission online 16 September 2005 Abstract Standard techniques of event-by-event detection of fission may failV proton-driven lead slowing-down neutron spectrometer at LANSCE where standard fission detectors are found

  7. Physics -Particle and Nuclear Physics | Theory of Nuclear Fission Springer is part of Springer Science+Business Media

    E-Print Network [OSTI]

    Pomorski, Krzysztof

    Physics - Particle and Nuclear Physics | Theory of Nuclear Fission © Springer is part of Springer Science+Business Media Theory of Nuclear Fission A Textbook Series: Lecture Notes in Physics, Vol. 838. Softcover, ISBN 978-3-642-23514-6 Due: October 31, 2011 69,95 About this book Theory of Nuclear Fission

  8. Probing nuclear shapes close to the fission limit with the giant dipole resonance in 216 M. Kmiecik,1

    E-Print Network [OSTI]

    Benzoni, Giovanna

    Probing nuclear shapes close to the fission limit with the giant dipole resonance in 216 Rn M of the nuclear shape distribution using the newest approach for the treatment of the fission barrier within(s): 21.60.Ev, 24.10.Lx, 24.30.Cz, 24.60.Dr I. INTRODUCTION The mechanism of nuclear fission induced

  9. Euratom Programme for Nuclear Research and Training Guide for Applicants: FP7-Fission-2007 GUIDE FOR APPLICANTS

    E-Print Network [OSTI]

    De Cindio, Fiorella

    Euratom Programme for Nuclear Research and Training Guide for Applicants: FP7-Fission-2007 i GUIDE FOR APPLICANTS Euratom Programme for Nuclear Research and Training Activities Call Identifier: FP7-Fission-2007 Programme for Nuclear Research and Training Guide for Applicants: FP7-Fission-2007 iii Contents TU1UT

  10. EUR 24802 EN -2011 Proceedings of the Scientific Workshop on Nuclear Fission Dynamics and the Emission of

    E-Print Network [OSTI]

    Pomorski, Krzysztof

    EUR 24802 EN - 2011 THEORY - 1 Proceedings of the Scientific Workshop on Nuclear Fission Dynamics ­particle emission is discussed. The nuclear fission process is described by a Langevin equation coupled developed in Ref. [4], and that the nuclear fission is a transport process [12]. The emission of photons

  11. TRACKING DYNAMIC BOUNDARIES BY EVOLVING Tingting Jiang

    E-Print Network [OSTI]

    Tingting Jiang

    range of applications. An example in image processing is the analysis of image sequences taken might track the boundary of a forest fire. Other applications include tracking spills of oil or poisonous gas, or clouds and weather patterns. In this dissertation, the author describes a new tracking

  12. Investigation of inconsistent ENDF/B-VII.1 independent and cumulative fission product yields with proposed revisions

    SciTech Connect (OSTI)

    Pigni, Marco T [ORNL; Francis, Matthew W [ORNL; Gauld, Ian C [ORNL

    2015-01-01T23:59:59.000Z

    A recent implementation of ENDF/B-VII. independent fission product yields and nuclear decay data identified inconsistencies in the data caused by the use of updated nuclear scheme in the decay sub-library that is not reflected in legacy fission product yield data. Recent changes in the decay data sub-library, particularly the delayed neutron branching fractions, result in calculated fission product concentrations that are incompatible with the cumulative fission yields in the library, and also with experimental measurements. A comprehensive set of independent fission product yields was generated for thermal and fission spectrum neutron induced fission for 235,238U and 239,241Pu in order to provide a preliminary assessment of the updated fission product yield data consistency. These updated independent fission product yields were utilized in the ORIGEN code to evaluate the calculated fission product inventories with experimentally measured inventories, with particular attention given to the noble gases. An important outcome of this work is the development of fission product yield covariance data necessary for fission product uncertainty quantification. The evaluation methodology combines a sequential Bayesian method to guarantee consistency between independent and cumulative yields along with the physical constraints on the independent yields. This work was motivated to improve the performance of the ENDF/B-VII.1 library in the case of stable and long-lived cumulative yields due to the inconsistency of ENDF/B-VII.1 fission p;roduct yield and decay data sub-libraries. The revised fission product yields and the new covariance data are proposed as a revision to the fission yield data currently in ENDF/B-VII.1.

  13. Track Finding Efficiency in BaBar

    E-Print Network [OSTI]

    T. Allmendinger; B. Bhuyan; D. N. Brown; H. Choi; S. Christ; R. Covarelli; M. Davier; A. G. Denig; M. Fritsch; A. Hafner; R. Kowalewski; O. Long; A. M. Lutz; M. Martinelli; D. R. Muller; I. M. Nugent; D. Lopes Pegna; M. V. Purohit; E. Prencipe; J. M. Roney; G. Simi; E. P. Solodov; A. V. Telnov; E. Varnes; R. Waldi; W. F. Wang; R. M. White

    2012-07-12T23:59:59.000Z

    We describe several studies to measure the charged track reconstruction efficiency and asymmetry of the BaBar detector. The first two studies measure the tracking efficiency of a charged particle using $\\tau$ and initial state radiation decays. The third uses the $\\tau$ decays to study the asymmetry in tracking, the fourth measures the tracking efficiency for low momentum tracks, and the last measures the reconstruction efficiency of $K_S^0$ particles. The first section also examines the stability of the measurements vs BaBar running periods.

  14. Infrared tag and track technique

    DOE Patents [OSTI]

    Partin, Judy K. (Idaho Falls, ID); Stone, Mark L. (Idaho Falls, ID); Slater, John (Albuquerque, NM); Davidson, James R. (Idaho Falls, ID)

    2007-12-04T23:59:59.000Z

    A method of covertly tagging an object for later tracking includes providing a material capable of at least one of being applied to the object and being included in the object, which material includes deuterium; and performing at least one of applying the material to the object and including the material in the object in a manner in which in the appearance of the object is not changed, to the naked eye.

  15. Single nanoparticle tracking spectroscopic microscope

    DOE Patents [OSTI]

    Yang, Haw (Moraga, CA); Cang, Hu (Berkeley, CA); Xu, Cangshan (Berkeley, CA); Wong, Chung M. (San Gabriel, CA)

    2011-07-19T23:59:59.000Z

    A system that can maintain and track the position of a single nanoparticle in three dimensions for a prolonged period has been disclosed. The system allows for continuously imaging the particle to observe any interactions it may have. The system also enables the acquisition of real-time sequential spectroscopic information from the particle. The apparatus holds great promise in performing single molecule spectroscopy and imaging on a non-stationary target.

  16. Uncertainty and sensitivity analysis of fission gas behavior in engineering-scale fuel modeling

    SciTech Connect (OSTI)

    G. Pastore; L.P. Swiler; J.D. Hales; S.R. Novascone; D.M. Perez; B.W. Spencer; L. Luzzi; P. Van Uffelen; R.L. Williamson

    2014-10-01T23:59:59.000Z

    The role of uncertainties in fission gas behavior calculations as part of engineering-scale nuclear fuel modeling is investigated using the BISON fuel performance code and a recently implemented physics-based model for the coupled fission gas release and swelling. Through the integration of BISON with the DAKOTA software, a sensitivity analysis of the results to selected model parameters is carried out based on UO2 single-pellet simulations covering different power regimes. The parameters are varied within ranges representative of the relative uncertainties and consistent with the information from the open literature. The study leads to an initial quantitative assessment of the uncertainty in fission gas behavior modeling with the parameter characterization presently available. Also, the relative importance of the single parameters is evaluated. Moreover, a sensitivity analysis is carried out based on simulations of a fuel rod irradiation experiment, pointing out a significant impact of the considered uncertainties on the calculated fission gas release and cladding diametral strain. The results of the study indicate that the commonly accepted deviation between calculated and measured fission gas release by a factor of 2 approximately corresponds to the inherent modeling uncertainty at high fission gas release. Nevertheless, higher deviations may be expected for values around 10% and lower. Implications are discussed in terms of directions of research for the improved modeling of fission gas behavior for engineering purposes.

  17. Rapid disappearance of shell effects in the fission of transfermium nuclei

    SciTech Connect (OSTI)

    Hulet, E.K.

    1983-01-01T23:59:59.000Z

    In the last fifteen years we have learned that nuclear shells have a very broad and pervasive impact on the fission process. In the first few decades after the discovery of nuclear fission, the nucleus was treated as a drop of liquid with smoothly varying attractive and repulsive forces. Although this model still forms the underlying basis for fission, we also observe large effects from the superimposition of shell corrections derived from coupling the quantum states of individual nucleons. The consequences of single-particle coupling on the fission process can be striking and may often overshadow that originating from the intrinsic liquid-drop component. Here, we point out several major features attributable to shell effects in the spontaneous fission (SF) of the lighter actinides, the sudden transition to symmetric fission in the fermium isotopes, and finally new experimental information indicating another transition in the SF of transfermium nuclides due to the disappearance of shell perturbations. In each transition, the abruptness is surprising, and for the moment, such rapid changes in fission behavior lack a theoretical rationale.

  18. A proposed standard on medical isotope production in fission reactors

    SciTech Connect (OSTI)

    Schenter, R. E. [Smart Bullets Inc., 2521 SW Luradel Street, Portland, OR 97219 (United States); Brown, G. J. [Ozarks Medical Center, Cancer Treatment Center, Shaw Medical Building, 1111 Kentucky Avenue, West Plains, MO 65775 (United States); Holden, C. S. [Thorenco LLC, 369 Pine Street, San Francisco, CA 94104 (United States)

    2006-07-01T23:59:59.000Z

    Authors Robert E. Sehenter, Garry Brown and Charles S. Holden argue that a Standard for 'Medical Isotope Production' is needed. Medical isotopes are becoming major components of application for the diagnosis and treatment of all the major diseases including all forms of cancer, heart disease, arthritis, Alzheimer's, among others. Current nuclear data to perform calculations is incomplete, dated or imprecise or otherwise flawed for many isotopes that could have significant applications in medicine. Improved data files will assist computational analyses to design means and methods for improved isotope production techniques in the fission reactor systems. Initial focus of the Standard is expected to be on neutron cross section and branching data for both fast and thermal reactor systems. Evaluated and reviewed tables giving thermal capture cross sections and resonance integrals for the major target and product medical isotopes would be the expected 'first start' for the 'Standard Working Group'. (authors)

  19. Transient fission gas release during direct electrical heating experiments

    SciTech Connect (OSTI)

    Fenske, G.R.; Emerson, J.E.; Savoie, F.E.

    1983-12-01T23:59:59.000Z

    The gas release behavior of irradiated EBR-II fuel was observed to be dependent on several factors: the presence of cladding, the retained gas content, and the energy absorbed. Fuel that retained in excess of 16 to 17 ..mu..moles/g of fission gas underwent spallation as the cladding melted and released 22 to 45% of its retained gas, while fuel with retained gas levels below approx. 15 to 16 ..mu..moles/g released less than approx. 9% of its gas as the cladding melted. During subsequent direct electrical heating ramps, fuel that did not spall released an additional quantity of gas (up to 4 ..mu..moles/g), depending on the energy absorbed.

  20. The SuperNEMO tracking detector

    E-Print Network [OSTI]

    M. Cascella

    2015-04-30T23:59:59.000Z

    The SuperNEMO detector will search for neutrinoless double beta decay at the Modane Underground Laboratory on the French-Italian border. This decay mode, if observed, would be proof that the neutrino is its own antiparticle, would constitute evidence for total lepton number violation, and could allow a measurement of the absolute neutrino mass. The SuperNEMO experiment is designed to reach a half-life sensitivity of $10^{26}$ years corresponding to an effective Majorana neutrino mass of $50-100~$meV. The SuperNEMO detector design allows complete topological reconstruction of the double beta decay event enabling excellent levels of background rejection. In the event of a discovery, such topological measurements will be vital in determining the nature of the lepton number violating process. This reconstruction will be performed by a gaseous tracking detector, consisting of 2034 drift cells per module operated in Geiger mode. The tracker of the Demonstrator Module is currently under construction in the UK. This paper presents the design of of the tracker, the construction procedure, and the current status of the construction and testing of the tracker cells.

  1. The SuperNEMO tracking detector

    E-Print Network [OSTI]

    Cascella, M

    2015-01-01T23:59:59.000Z

    The SuperNEMO detector will search for neutrinoless double beta decay at the Modane Underground Laboratory on the French-Italian border. This decay mode, if observed, would be proof that the neutrino is its own antiparticle, would constitute evidence for total lepton number violation, and could allow a measurement of the absolute neutrino mass. The SuperNEMO experiment is designed to reach a half-life sensitivity of $10^{26}$ years corresponding to an effective Majorana neutrino mass of $50-100~$meV. The SuperNEMO detector design allows complete topological reconstruction of the double beta decay event enabling excellent levels of background rejection. In the event of a discovery, such topological measurements will be vital in determining the nature of the lepton number violating process. This reconstruction will be performed by a gaseous tracking detector, consisting of 2034 drift cells per module operated in Geiger mode. The tracker of the Demonstrator Module is currently under construction in the UK. This ...

  2. Neutron Cross Section Covariances for Structural Materials and Fission Products

    SciTech Connect (OSTI)

    Hoblit, S.; Hoblit,S.; Cho,Y.-S.; Herman,M.; Mattoon,C.M.; Mughabghab,S.F.; Oblozinsky,P.; Pigni,M.T.; Sonzogni,A.A.

    2011-12-01T23:59:59.000Z

    We describe neutron cross section covariances for 78 structural materials and fission products produced for the new US evaluated nuclear reaction library ENDF/B-VII.1. Neutron incident energies cover full range from 10{sup -5} eV to 20 MeV and covariances are primarily provided for capture, elastic and inelastic scattering as well as (n,2n). The list of materials follows priorities defined by the Advanced Fuel Cycle Initiative, the major application being data adjustment for advanced fast reactor systems. Thus, in addition to 28 structural materials and 49 fission products, the list includes also {sup 23}Na which is important fast reactor coolant. Due to extensive amount of materials, we adopted a variety of methodologies depending on the priority of a specific material. In the resolved resonance region we primarily used resonance parameter uncertainties given in Atlas of Neutron Resonances and either applied the kernel approximation to propagate these uncertainties into cross section uncertainties or resorted to simplified estimates based on integral quantities. For several priority materials we adopted MF32 covariances produced by SAMMY at ORNL, modified by us by adding MF33 covariances to account for systematic uncertainties. In the fast neutron region we resorted to three methods. The most sophisticated was EMPIRE-KALMAN method which combines experimental data from EXFOR library with nuclear reaction modeling and least-squares fitting. The two other methods used simplified estimates, either based on the propagation of nuclear reaction model parameter uncertainties or on a dispersion analysis of central cross section values in recent evaluated data files. All covariances were subject to quality assurance procedures adopted recently by CSEWG. In addition, tools were developed to allow inspection of processed covariances and computed integral quantities, and for comparing these values to data from the Atlas and the astrophysics database KADoNiS.

  3. Fission product behavior during the PBF (Power Burst Facility) Severe Fuel Damage Test 1-1

    SciTech Connect (OSTI)

    Hartwell, J K; Petti, D A; Hagrman, D L; Jensen, S M; Cronenberg, A W

    1987-05-01T23:59:59.000Z

    In response to the accident at Three Mile Island Unit 2 (TMI-2), the United States Nuclear Regulatory Commission (USNRC) initiated a series of Severe Fuel Damage tests that were performed in the Power Burst Facility at the Idaho National Engineering Laboratory to obtain data necessary to understand (a) fission product release, transport, and deposition; (b) hydrogen generation; and (c) fuel/cladding material behavior during degraded core accidents. Data are presented about fission product behavior noted during the second experiment of this series, the Severe Fuel Damage Test 1-1, with an in-depth analysis of the fission product release, transport, and deposition phenomena that were observed. Real-time release and transport data of certain fission products were obtained from on-line gamma spectroscopy measurements. Liquid and gas effluent grab samples were collected at selected periods during the test transient. Additional information was obtained from steamline deposition analysis. From these and other data, fission product release rates and total release fractions are estimated and compared with predicted release behavior using current models. Fission product distributions and a mass balance are also summarized, and certain probable chemical forms are predicted for iodine, cesium, and tellurium. An in-depth evaluation of phenomena affecting the behavior of the high-volatility fission products - xenon, krypton, iodine, cesium, and tellurium - is presented. Analysis indicates that volatile release from fuel is strongly influenced by parameters other than fuel temperature. Fission product behavior during transport through the Power Burst Facility effluent line to the fission product monitoring system is assessed. Tellurium release behavior is also examined relatve to the extent of Zircaloy cladding oxidation. 81 fig., 53 tabs.

  4. Prompt muon-induced fission: a probe for nuclear energy dissipation

    E-Print Network [OSTI]

    Volker E. Oberacker

    1999-05-04T23:59:59.000Z

    We solve the time-dependent Dirac equation for a muon which is initially bound to a fissioning actinide nucleus. The computations are carried out on a 3-D cartesian lattice utilizing the Basis-Spline collocation method. The muon dynamics is sensitive to the nuclear energy dissipation between the outer fission barrier and the scission point. From a comparison with experimental data we find a dissipated energy of about 10 MeV and a fission time delay due to friction of order $2 \\times 10^{-21}$ s.

  5. Detecting special nuclear materials in containers using high-energy gamma rays emitted by fission products

    DOE Patents [OSTI]

    Norman, Eric B. (Oakland, CA); Prussin, Stanley G. (Kensington, CA)

    2007-10-02T23:59:59.000Z

    A method and a system for detecting the presence of special nuclear materials in a container. The system and its method include irradiating the container with an energetic beam, so as to induce a fission in the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  6. Delayed neutron yield from fast neutron induced fission of sup 2 sup 3 sup 8 U

    E-Print Network [OSTI]

    Piksaikin, V M; Isaev, S G; Kazakov, L E; Roshchenko, V A; Tertytchnyi, R G

    2001-01-01T23:59:59.000Z

    The measurements of the total delayed neutron yield from fast neutron induced fission of sup 2 sup 3 sup 8 U were made. The experimental method based on the periodic irradiation of the fissionable sample by neutrons from a suitable nuclear reaction had been employed. The preliminary results on the energy dependence of the total delayed neutron yield from fission of sup 2 sup 3 sup 8 U are obtained. According to the comparison of experimental data with our prediction based on correlation properties of delayed neutron characteristics, it is concluded that the value of the total delayed neutron yield near the threshold of (n,f) reaction is not a constant.

  7. Beta-delayed fission and the production of very heavy nuclides from rapid neutron capture processes

    E-Print Network [OSTI]

    Wene, C O

    1976-01-01T23:59:59.000Z

    The experimental probabilities are larger than expected, indicating an increase in level densities above the fission barriers due to the loss of symmetry at the inner barrier. As a consequence beta delayed fission may occur also in the r-process path. When discussing the production of superheavy nuclides by the r-process, beta delayed fission has therefore to be considered not only in the decay back but also for the cut-off. The results from earlier calculations on the yield of stable nuclides from nuclear explosions and r-process production ratios for chronometric pairs are carried over into a new model with only small changes. (21 refs).

  8. Background and Derivation of ANS-5.4 Standard Fission Product Release Model

    SciTech Connect (OSTI)

    Beyer, Carl E.; Turnbull, Andrew J.

    2010-01-29T23:59:59.000Z

    This background report describes the technical basis for the newly proposed American Nuclear Society (ANS) 5.4 standard, Methods for Calculating the Fractional Release of Volatile Fission Products from Oxide Fuels. The proposed ANS 5.4 standard provides a methodology for determining the radioactive fission product releases from the fuel for use in assessing radiological consequences of postulated accidents that do not involve abrupt power transients. When coupled with isotopic yields, this method establishes the 'gap activity,' which is the inventory of volatile fission products that are released from the fuel rod if the cladding are breached.

  9. Fission fragment mass yield deduced from density distribution in the pre-scission configuration

    E-Print Network [OSTI]

    M. Warda; A. Zdeb

    2015-02-19T23:59:59.000Z

    Static self-consistent methods usually allow to determine the most probable fission fragments mass asymmetry. We have applied random neck rupture mechanism to the nuclei in the configuration at the end of fission paths. Fission fragment mass distributions have been deduced from the pre-scission nuclear density distribution obtained from the self-consistent calculations. Potential energy surfaces as well as nuclear shapes have been calculated in the fully microscopic theory, namely the constrained Hartree-Fock-Bogolubov model with the effective Gogny D1S density-dependent interaction. The method has been applied for analysis of fission of Fm-256,258, Cf-252 and Hg-180 and compared with the experimental data.

  10. Fission fragment mass yield deduced from density distribution in the pre-scission configuration

    E-Print Network [OSTI]

    Warda, M

    2015-01-01T23:59:59.000Z

    Static self-consistent methods usually allow to determine the most probable fission fragments mass asymmetry. We have applied random neck rupture mechanism to the nuclei in the configuration at the end of fission paths. Fission fragment mass distributions have been deduced from the pre-scission nuclear density distribution obtained from the self-consistent calculations. Potential energy surfaces as well as nuclear shapes have been calculated in the fully microscopic theory, namely the constrained Hartree-Fock-Bogolubov model with the effective Gogny D1S density-dependent interaction. The method has been applied for analysis of fission of Fm-256,258, Cf-252 and Hg-180 and compared with the experimental data.

  11. Comment on Mean First Passage Time for Nuclear Fission and the Emission of Light Particles

    E-Print Network [OSTI]

    K. -H. Schmidt; J. Benlliure; D. Boilley; A. Heinz; A. Junghans; B. Jurado; A. Kelic; J. Pereira; C. Schmitt; O. Yordanov

    2003-07-25T23:59:59.000Z

    Theoretical methods, interpretations and conclusions on the fission dynamics in a recent publication of H. Hofmann and F. A. Ivanyuk on the mean first passage time are critically considered.

  12. FileName//FileDate//PNNL-SA-##### DPA Calculational Methodologies Used in Fission

    E-Print Network [OSTI]

    McDonald, Kirk

    FileName//FileDate//PNNL-SA-##### DPA Calculational Methodologies Used in Fission and Fusion Reactor Materials Applications David Wootan - david.wootan@pnnl.gov, 1-509-372-6865 Radiation Damage

  13. Molten salt considerations for accelerator-driven subcritical fission to close the nuclear fuel cycle

    SciTech Connect (OSTI)

    Sooby, Elizabeth; Baty, Austin; Gerity, James; McIntyre, Peter; Melconian, Karie; Pogue, Nathaniel; Sattarov, Akhdiyor [Department of Physics and Astronomy, Texas A and M University, 4242 TAMU, College Station TX 77843 (United States); Adams, Marvin; Tsevkov, Pavel [Nuclear Engineering, Texas A and M University, Spence St., College Station TX 77843 (United States); Phongikaroon, Supathorn [Center for Advanced Energy Studies, University of Idaho, 995 University Blvd, Idaho Falls, ID 83401 (United States); Simpson, Michael; Tripathy, Prabhat [Materials Fuels Complex, Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

    2013-04-19T23:59:59.000Z

    The host salt selection, molecular modeling, physical chemistry, and processing chemistry are presented here for an accelerator-driven subcritical fission in a molten salt core (ADSMS). The core is fueled solely with the transuranics (TRU) and long-lived fission products (LFP) from used nuclear fuel. The neutronics and salt composition are optimized to destroy the transuranics by fission and the long-lived fission products by transmutation. The cores are driven by proton beams from a strong-focusing cyclotron stack. One such ADSMS system can destroy the transuranics in the used nuclear fuel produced by a 1GWe conventional reactor. It uniquely provides a method to close the nuclear fuel cycle for green nuclear energy.

  14. Recent Results and Fabrication of Micro-Pocket Fission Detectors (MPFD)

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    environments found in a reactor core. Self-powered neutron detectors (SPND) have the advantages of no voltage to noise ratio of the fission and ionization chambers, the low voltage requirements and small size of SPND

  15. Ternary particles with extreme N/Z ratios from neutron-induced fission

    SciTech Connect (OSTI)

    Koster, U.; Faust, H.; Friedrichs, T.; Oberstedt, S.; Fioni, G.; Grob, M.; Ahmad, I. J.; Devlin, M.; Heinz, A.; Kondev, F. G.; Lauritsen, T.; Sarantites, D. G.; Siem, S.; Sobotka, L. G.; Sonzogni, A.

    2000-05-16T23:59:59.000Z

    The existing ternary fission models can well reproduce the yields of the most abundant light charged particles. However, these models tend to significantly overestimate the yields of ternary particles with an extreme N/Z ratio: {sup 3}He, {sup 11}Li, {sup 14}Be, etc. The experimental yields of these isotopes were investigated with the recoil separator LOHENGRIN down to a level of 10{sup {minus}10} per fission. Results from the fissioning systems {sup 233}U (n{sub th}, f), {sup 235}U(n{sub th},f), {sup 239}Pu(n{sub th},f) {sup 241}Pu(n{sub th},f) and {sup 245}Cm(n{sub th},f) are presented and the implications for the ternary fission models are discussed.

  16. /sup 3/He-induced fission of nuclei 159

    SciTech Connect (OSTI)

    Becchetti, F.D.; Hicks, K.H.; Fields, C.A.; Peterson, R.J.; Raymond, R.S.; Ristinen, R.A.; Ullmann, J.L.; Zaidins, C.S.

    1983-09-01T23:59:59.000Z

    The fission of nuclei with 159< or =A< or =232 induced by the bombardment of 19.1 to 44.5 MeV /sup 3/He ions has been measured using solid-state detectors with time-of-flight measurements. Analysis with statistical fission theory, including precompound nucleon emission, indicates fission barriers which decrease only slightly relative to the liquid-drop model values with decreasing Z, approaching about 90% of the liquid-drop model barrier for Aroughly-equal160. These results are in contrast with measurements at higher angular momenta which indicate much lower fission barriers (60 to 70 % of the liquid-drop model) for this mass region. The angular correlations indicate complete, or slightly greater than complete momentum transfer to the compound system. This is in opposition to that observed using heavier projectiles where incomplete momentum transfer is probable.

  17. Enhanced external quantum efficiency in an organic photovoltaic cell via singlet fission exciton sensitizer

    E-Print Network [OSTI]

    Reusswig, Philip David

    We demonstrate bilayer organic photovoltaic cells that incorporate a singlet exciton fission sensitizer layer to increase the external quantum efficiency (EQE). This solar cell architecture is realized by pairing the singlet ...

  18. Slow light enhanced singlet exciton fission solar cells with a 126% yield of electrons per photon

    E-Print Network [OSTI]

    Thompson, Nicholas J.

    Singlet exciton fission generates two triplet excitons per absorbed photon. It promises to increase the power extracted from sunlight without increasing the number of photovoltaic junctions in a solar cell. We demonstrate ...

  19. Two-axis tracking solar collector mechanism

    DOE Patents [OSTI]

    Johnson, Kenneth C. (201 W. California Ave., #401, Sunnyvale, CA 94086)

    1990-01-01T23:59:59.000Z

    This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

  20. Two-axis tracking solar collector mechanism

    DOE Patents [OSTI]

    Johnson, Kenneth C. (201 W. California Ave. #705, Sunnyvale, CA 94086)

    1992-01-01T23:59:59.000Z

    This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion.

  1. Two-axis tracking solar collector mechanism

    DOE Patents [OSTI]

    Johnson, K.C.

    1992-12-08T23:59:59.000Z

    This invention is a novel solar tracking mechanism incorporating a number of practical features that give it superior environmental resilience and exceptional tracking accuracy. The mechanism comprises a lightweight space-frame assembly supporting an array of point-focus Fresnel lenses in a two-axis tracking structure. The system is enclosed under a glass cover which isolates it from environmental exposure and enhances tracking accuracy by eliminating wind loading. Tracking accuracy is also enhanced by the system's broad-based tracking support. The system's primary intended application would be to focus highly concentrated sunlight into optical fibers for transmission to core building illumination zones, and the system may also have potential for photovoltaic or photothermal solar energy conversion. 16 figs.

  2. Fission-suppressed fusion breeder on the thorium cycle and nonproliferation

    SciTech Connect (OSTI)

    Moir, R. W. [Vallecitos Molten Salt Research, 607 E. Vallecitos Rd., Livermore, CA 94550 925-447-8804 (United States)

    2012-06-19T23:59:59.000Z

    Fusion reactors could be designed to breed fissile material while suppressing fissioning thereby enhancing safety. The produced fuel could be used to startup and makeup fuel for fission reactors. Each fusion reaction can produce typically 0.6 fissile atoms and release about 1.6 times the 14 MeV neutron's energy in the blanket in the fission-suppressed design. This production rate is 2660 kg/1000 MW of fusion power for a year. The revenues would be doubled from such a plant by selling fuel at a price of 60/g and electricity at $0.05/kWh for Q=P{sub fusion}/P{sub input}=4. Fusion reactors could be designed to destroy fission wastes by transmutation and fissioning but this is not a natural use of fusion whereas it is a designed use of fission reactors. Fusion could supply makeup fuel to fission reactors that were dedicated to fissioning wastes with some of their neutrons. The design for safety and heat removal and other items is already accomplished with fission reactors. Whereas fusion reactors have geometry that compromises safety with a complex and thin wall separating the fusion zone from the blanket zone where wastes could be destroyed. Nonproliferation can be enhanced by mixing {sup 233}U with {sup 238}U. Also nonproliferation is enhanced in typical fission-suppressed designs by generating up to 0.05 {sup 232}U atoms for each {sup 233}U atom produced from thorium, about twice the IAEA standards of 'reduced protection' or 'self protection.' With 2.4%{sup 232}U, high explosive material is predicted to degrade owing to ionizing radiation after a little over 1/2 year and the heat rate is 77 W just after separation and climbs to over 600 W ten years later. The fissile material can be used to fuel most any fission reactor but is especially appropriate for molten salt reactors (MSR) also called liquid fluoride thorium reactors (LFTR) because of the molten fuel does not need hands on fabrication and handling.

  3. Tracking system for solar collectors

    DOE Patents [OSTI]

    Butler, Barry L. (Golden, CO)

    1984-01-01T23:59:59.000Z

    A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

  4. Tracking system for solar collectors

    DOE Patents [OSTI]

    Butler, B.

    1980-10-01T23:59:59.000Z

    A tracking system is provided for pivotally mounted spaced-apart solar collectors. A pair of cables is connected to spaced-apart portions of each collector, and a driver displaces the cables, thereby causing the collectors to pivot about their mounting, so as to assume the desired orientation. The collectors may be of the cylindrical type as well as the flat-plate type. Rigid spar-like linkages may be substituted for the cables. Releasable attachments of the cables to the collectors is also described, as is a fine tuning mechanism for precisely aligning each individual collector.

  5. Tracking the Elusive QOOH Radical

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2, 2003Tool ofTopo II:7.1Tracking Living Cells

  6. Tracking the Elusive QOOH Radical

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2, 2003Tool ofTopo II:7.1Tracking Living

  7. Tracking the Elusive QOOH Radical

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesisAppliances » TopTours SignTracking

  8. The use of accelerators for the study of delayed neutrons from fission: Significance to reactor control

    SciTech Connect (OSTI)

    Walker, J.; Owen, J.G.; Weaver, D.R.

    1981-04-01T23:59:59.000Z

    Delayed neutrons from fission are very important in the kinetic behaviour of nuclear reactors and in the assaying of nuclear materials. Information is necessary on lifetimes, yields, and energies, and the paper shows the part which accelerators have played in providing it. Special attention is paid to yields and to recent measurements of delayed-neutron energies in fast fission; attention is drawn to gaps or uncertainties in knowledge and, therefore, to the need for new measurements.

  9. Description of Induced Nuclear Fission with Skyrme Energy Functionals: II. Finite Temperature Effects

    E-Print Network [OSTI]

    N. Schunck; D. Duke; H. Carr

    2015-01-23T23:59:59.000Z

    Understanding the mechanisms of induced nuclear fission for a broad range of neutron energies could help resolve fundamental science issues, such as the formation of elements in the universe, but could have also a large impact on societal applications in energy production or nuclear waste management. The goal of this paper is to set up the foundations of a microscopic theory to study the static aspects of induced fission as a function of the excitation energy of the incident neutron, from thermal to fast neutrons. To account for the high excitation energy of the compound nucleus, we employ a statistical approach based on finite-temperature nuclear density functional theory with Skyrme energy densities, which we benchmark on the 239 Pu(n,f) reaction. We compute the evolution of the least-energy fission pathway across multidimensional potential energy surfaces with up to five collective variables as a function of the nuclear temperature, and predict the evolution of both the inner and outer fission barriers as a function of the excitation energy of the compound nucleus. We show that the coupling to the continuum induced by the finite temperature is negligible in the range of neutron energies relevant for many applications of neutron-induced fission. We prove that the concept of quantum localization introduced recently can be extended to T > 0, and we apply the method to study the interaction energy and total kinetic energy of fission fragments as a function of the temperature for the most probable fission. While large uncertainties in theoretical modeling remain, we conclude that finite-temperature nuclear density functional may provide a useful framework to obtain accurate predictions of fission fragment properties.

  10. INPUT CONSTRAINED ADAPTIVE TRACKING WITH APPLICATIONS TO

    E-Print Network [OSTI]

    Knobloch,Jürgen

    as models in several industries including continuous polymerization reactors, distillation columns tracking ac- curacy, quantified by > 0 set by the designer, is ensured. The adaptive control strategy does

  11. Energy Intensity Baselining and Tracking Guidance

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

    Learn more at betterbuildings.energy.gov Energy Intensity Baselining and Tracking Guidance i Preface The U.S. Department of Energy's (DOE's) Better Buildings, Better Plants Program...

  12. Beta-delayed fission and neutron emission calculations for the actinide cosmochronometers

    SciTech Connect (OSTI)

    Meyer, B.S.; Howard, W.M.; Mathews, G.J.; Takahashi, K.; Moeller, P.; Leander, G.A.

    1989-05-01T23:59:59.000Z

    The Gamow-Teller beta-strength distributions for 19 neutron-rich nuclei, including ten of interest for the production of the actinide cosmochronometers, are computed microscopically with a code that treats nuclear deformation explicitly. The strength distributions are then used to calculate the beta-delayed fission, neutron emission, and gamma deexcitation probabilities for these nuclei. Fission is treated both in the complete damping and WKB approximations for penetrabilities through the nuclear potential-energy surface. The resulting fission probabilities differ by factors of 2 to 3 or more from the results of previous calculations using microscopically computed beta-strength distributions around the region of greatest interest for production of the cosmochronometers. The indications are that a consistent treatment of nuclear deformation, fission barriers, and beta-strength functions is important in the calculation of delayed fission probabilities and the production of the actinide cosmochronometers. Since we show that the results are very sensitive to relatively small changes in model assumptions, large chronometric ages for the Galaxy based upon high beta-delayed fission probabilities derived from an inconsistent set of nuclear data calculations must be considered quite uncertain.

  13. Microscopic description of fission in Uranium isotopes with the Gogny energy density functional

    E-Print Network [OSTI]

    R. Rodriguez-Guzman; L. M. Robledo

    2014-05-25T23:59:59.000Z

    The most recent parametrizations D1S, D1N and D1M of the Gogny energy density functional are used to describe fission in the isotopes $^{232-280}$ U. Fission paths, collective masses and zero point quantum corrections, obtained within the constrained Hartree-Fock-Bogoliubov approximation, are used to compute the systematics of the spontaneous fission half-lives $t_\\mathrm{SF}$, the masses and charges of the fission fragments as well as their intrinsic shapes. The Gogny-D1M parametrization has been benchmarked against available experimental data on inner and second barrier heights, excitation energies of the fission isomers and half-lives in a selected set of Pu, Cm, Cf, Fm, No, Rf, Sg, Hs and Fl nuclei. It is concluded that D1M represents a reasonable starting point to describe fission in heavy and superheavy nuclei. Special attention is also paid to understand the uncertainties in the predicted $t_\\mathrm{SF}$ values arising from the different building blocks entering the standard semi-classical Wentzel-Kramers-Brillouin formula. Although the uncertainties are large, the trend with mass or neutron numbers are well reproduced and therefore the theory still has predictive power. In this respect, it is also shown that modifications of a few per cent in the pairing strength can have a significant impact on the collective masses leading to uncertainties in the $t_\\mathrm{SF}$ values of several orders of magnitude.

  14. TANG et al.: DETECTION AND TRACKING OF OCCLUDED PEOPLE 1 Detection and Tracking of Occluded People

    E-Print Network [OSTI]

    with many subjects that partially occlude each other. This limitation is due to the fact that current peopleTANG et al.: DETECTION AND TRACKING OF OCCLUDED PEOPLE 1 Detection and Tracking of Occluded People We consider the problem of detection and tracking of multiple people in crowded street scenes. State

  15. April 6, 2010 Fast Track and Back Track between Master's and Doctoral Programs

    E-Print Network [OSTI]

    Barthelat, Francois

    April 6, 2010 Fast Track and Back Track between Master's and Doctoral Programs Procedures for Graduate Programs and Students "Transfer" from the Master's to Doctoral Program (Fast tracking procedures) Upon recommendation by the program and approval by Graduate and Postdoctoral Studies (GPS

  16. Eye-Tracking: Characteristics and Methods Eye-Tracking: Research Areas and Applications

    E-Print Network [OSTI]

    Richardson, Daniel C.

    1 Part 1 Eye-Tracking: Characteristics and Methods Part 2 Eye-Tracking: Research Areas. & Bowlin, G. (Eds.) [ PREPRINT, FEB 2004. PLEASE DO NOT QUOTE ] #12;2 Eye-Tracking: Characteristics and Methods Introduction Eye movements are arguably the most frequent of all human movements (Bridgeman, 1992

  17. 3D Tracking of Human Locomotion: A Tracking as Recognition Approach Tao Zhao Ram Nevatia

    E-Print Network [OSTI]

    Southern California, University of

    3D Tracking of Human Locomotion: A Tracking as Recognition Approach £ Tao Zhao Ram Nevatia, tracking re- quires knowledge of initial state; this is a difficult problem and a user often specifies it manually. These difficulties call for stronger prior knowledge on the motion being studied and stronger

  18. Engineering Report on the Fission Gas Getter Concept

    SciTech Connect (OSTI)

    Ecker, Lynne; Ghose, Sanjit; Gill, Simerjeet; Thallapally, Praveen K.; Strachan, Denis M.

    2012-11-01T23:59:59.000Z

    In 2010, the Department of Energy (DOE) requested that a Brookhaven National Laboratory (BNL)-led team research the possibility of using a getter material to reduce the pressure in the plenum region of a light water reactor fuel rod. During the first two years of the project, several candidate materials were identified and tested using a variety of experimental techniques, most with xenon as a simulant for fission products. Earlier promising results for candidate getter materials were found to be incorrect, caused by poor experimental techniques. In May 2012, it had become clear that none of the initial materials had demonstrated the ability to adsorb xenon in the quantities and under the conditions needed. Moreover, the proposed corrective action plan could not meet the schedule needed by the project manager. BNL initiated an internal project review which examined three questions: 1. Which materials, based on accepted materials models, might be capable of absorbing xenon? 2. Which experimental techniques are capable of not only detecting if xenon has been absorbed but also determine by what mechanism and the resulting molecular structure? 3. Are the results from the previous techniques useable now and in the future? As part of the second question, the project review team evaluated the previous experimental technique to determine why incorrect results were reported in early 2012. This engineering report is a summary of the current status of the project review, description of newly recommended experiments and results from feasibility studies at the National Synchrotron Light Source (NSLS).

  19. Micro-Pocket Fission Detectors (MPFD) For Fuel Assembly Analysis

    SciTech Connect (OSTI)

    Troy Unruh; Michael Reichenberger; Phillip Ugorowski

    2013-09-01T23:59:59.000Z

    Neutron sensors capable of real-time measurement of thermal flux, fast flux, and temperature in a single miniaturized probe are needed in irradiation tests required to demonstrate the performance of candidate new fuels, and cladding materials. In-core ceramic-based miniature neutron detectors or “Micro-Pocket Fission Detectors” (MPFDs) have been studied at Kansas State University (KSU). The first MPFD prototypes were tested in various neutron fields at the KSU TRIGA research reactor with successful results. Currently, a United States Department of Energy-sponsored joint KSU/Idaho National Laboratory (INL) effort is underway to develop a high-temperature, high-pressure version of the MPFD using radiation-resistant, high temperature materials, which would be capable of withstanding irradiation test conditions in high performance material and test reactors (MTRs). Ultimately, this more compact, more accurate, and longer lifetime flux sensor for critical mock-ups, existing and advanced reactor designs, high performance MTRs, and transient test reactors has the potential to lead to higher accuracy and resolution data from irradiation testing, more detailed core flux measurements and enhanced fuel assembly processing. Prior evaluations by KSU indicate that these sensors could also be used to monitor burn-up of nuclear fuel. If integrated into nuclear fuel assemblies, MPFDs offer several advantages to current spent fuel management systems.

  20. SNIF: A Futuristic Neutrino Probe for Undeclared Nuclear Fission Reactors

    E-Print Network [OSTI]

    Thierry Lasserre; Maximilien Fechner; Guillaume Mention; Romain Reboulleau; Michel Cribier; Alain Letourneau; David Lhuillier

    2010-11-16T23:59:59.000Z

    Today reactor neutrino experiments are at the cutting edge of fundamental research in particle physics. Understanding the neutrino is far from complete, but thanks to the impressive progress in this field over the last 15 years, a few research groups are seriously considering that neutrinos could be useful for society. The International Atomic Energy Agency (IAEA) works with its Member States to promote safe, secure and peaceful nuclear technologies. In a context of international tension and nuclear renaissance, neutrino detectors could help IAEA to enforce the Treaty on the Non-Proliferation of Nuclear Weapons (NPT). In this article we discuss a futuristic neutrino application to detect and localize an undeclared nuclear reactor from across borders. The SNIF (Secret Neutrino Interactions Finder) concept proposes to use a few hundred thousand tons neutrino detectors to unveil clandestine fission reactors. Beyond previous studies we provide estimates of all known background sources as a function of the detector's longitude, latitude and depth, and we discuss how they impact the detectability.

  1. Fusion materials irradiations at MaRIE's fission fusion facility

    SciTech Connect (OSTI)

    Pitcher, Eric J [Los Alamos National Laboratory

    2010-10-06T23:59:59.000Z

    Los Alamos National Laboratory's proposed signature facility, MaRIE, will provide scientists and engineers with new capabilities for modeling, synthesizing, examining, and testing materials of the future that will enhance the USA's energy security and national security. In the area of fusion power, the development of new structural alloys with better tolerance to the harsh radiation environments expected in fusion reactors will lead to improved safety and lower operating costs. The Fission and Fusion Materials Facility (F{sup 3}), one of three pillars of the proposed MaRIE facility, will offer researchers unprecedented access to a neutron radiation environment so that the effects of radiation damage on materials can be measured in-situ, during irradiation. The calculated radiation damage conditions within the F{sup 3} match, in many respects, that of a fusion reactor first wall, making it well suited for testing fusion materials. Here we report in particular on two important characteristics of the radiation environment with relevancy to radiation damage: the primary knock-on atom spectrum and the impact of the pulse structure of the proton beam on temporal characteristics of the atomic displacement rate. With respect to both of these, analyses show the F{sup 3} has conditions that are consistent with those of a steady-state fusion reactor first wall.

  2. DISTRIBUTED EVENT LOCALIZATION AND TRACKING ALGORITHM (DELTA)

    E-Print Network [OSTI]

    Braun, Torsten

    in a distributed event localization and tracking algorithm (DELTA). DELTA is extended with energy-efficient network management, event classification functionality and an energy based source localization. The energy;#12;Abstract Different approaches to do event detection, tracking, localization and classification have been

  3. Differential Kalman Filteringfor Tracking Rayleigh Fading Channels

    E-Print Network [OSTI]

    Gulak, P. Glenn

    Differential Kalman Filteringfor Tracking Rayleigh Fading Channels M. J. Ornidi,S.Gazol;F? G. Gulak in the tracking of a fadingchannel plays an essential role in many wireless receivers. The conventional Kalman implementation. In this paper a new approach is proposed for the implementation of the Kalman filter based

  4. Microscopic dynamical description of proton-induced fission with the Constrained Molecular Dynamics (CoMD) Model

    E-Print Network [OSTI]

    N. Vonta; G. A. Souliotis; M. Veselsky; A. Bonasera

    2015-06-16T23:59:59.000Z

    The microscopic description of nuclear fission still remains a topic of intense basic research. Un- derstanding nuclear fission, apart from a theoretical point of view, is of practical importance for energy production and the transmutation of nuclear waste. In nuclear astrophysics, fission sets the upper limit to the nucleosynthesis of heavy elements via the r-process. In this work we initiated a systematic study of intermediate energy proton-induced fission using the Constrained Molecu- lar Dynamics (CoMD) code. The CoMD code implements an effective interaction with a nuclear matter compressibility of K=200 (soft EOS) with several forms of the density dependence of the nucleon-nucleon symmetry potential. Moreover, a constraint is imposed in the phase-space occu- pation for each nucleon restoring the Pauli principle at each time step of the collision. A proper choice of the surface parameter of the effective interaction has been made to describe fission. In this work, we present results of fission calculations for proton-induced reactions on : a) 232 Th at 27 and 63 MeV, b) 235 U at 10, 30, 60 and 100 MeV, and c) 238 U at 100 and 660 MeV. The calculated observables include fission-fragment mass distributions, total fission energies, neutron multiplicities and fission times. These observables are compared to available experimental data. We show that the microscopic CoMD code is able to describe the complicated many-body dynamics of the fission process at intermediate and high energy and give a reasonable estimate of the fission time scale. Sensitivity of the results to the density dependence of the nucleon symmetry potential (and, thus, the nuclear symmetry energy) is found. Further improvements of the code are necessary to achieve a satisfactory description of low energy fission in which shell effects play a dominant role.

  5. P-odd, P-even, and T-odd asymmetries in true quaternary fission of nuclei

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V. [Voronezh State University (Russian Federation)] [Voronezh State University (Russian Federation)

    2013-04-15T23:59:59.000Z

    The coefficients of P-odd, P-even, and T -odd asymmetries for a third and a fourth prescission particle emitted in the true quaternary fission of nuclei that was induced by polarized cold neutrons were studied on the basis of quantum-mechanical fission theory. By using non-evaporation (nonadiabatic) mechanisms of light-particle emission, these coefficients were compared with the analogous coefficients for prescission third particles emitted in the ternary fission of nuclei.

  6. Position and orientation tracking system

    DOE Patents [OSTI]

    Burks, B.L.; DePiero, F.W.; Armstrong, G.A.; Jansen, J.F.; Muller, R.C.; Gee, T.F.

    1998-05-05T23:59:59.000Z

    A position and orientation tracking system presents a laser scanning apparatus having two measurement pods, a control station, and a detector array. The measurement pods can be mounted in the dome of a radioactive waste storage silo. Each measurement pod includes dual orthogonal laser scanner subsystems. The first laser scanner subsystem is oriented to emit a first line laser in the pan direction. The second laser scanner is oriented to emit a second line laser in the tilt direction. Both emitted line lasers scan planes across the radioactive waste surface to encounter the detector array mounted on a target robotic vehicle. The angles of incidence of the planes with the detector array are recorded by the control station. Combining measurements describing each of the four planes provides data for a closed form solution of the algebraic transform describing the position and orientation of the target robotic vehicle. 14 figs.

  7. Position and orientation tracking system

    DOE Patents [OSTI]

    Burks, Barry L. (Oak Ridge, TN); DePiero, Fred W. (Knoxville, TN); Armstrong, Gary A. (Oak Ridge, TN); Jansen, John F. (Knoxville, TN); Muller, Richard C. (Oak Ridge, TN); Gee, Timothy F. (Riceville, TN)

    1998-01-01T23:59:59.000Z

    A position and orientation tracking system presents a laser scanning appaus having two measurement pods, a control station, and a detector array. The measurement pods can be mounted in the dome of a radioactive waste storage silo. Each measurement pod includes dual orthogonal laser scanner subsystems. The first laser scanner subsystem is oriented to emit a first line laser in the pan direction. The second laser scanner is oriented to emit a second line laser in the tilt direction. Both emitted line lasers scan planes across the radioactive waste surface to encounter the detector array mounted on a target robotic vehicle. The angles of incidence of the planes with the detector array are recorded by the control station. Combining measurements describing each of the four planes provides data for a closed form solution of the algebraic transform describing the position and orientation of the target robotic vehicle.

  8. A Review of Previous Research in Direct Energy Conversion Fission Reactors

    SciTech Connect (OSTI)

    DUONG,HENRY; POLANSKY,GARY F.; SANDERS,THOMAS L.; SIEGEL,MALCOLM D.

    1999-09-22T23:59:59.000Z

    From the earliest days of power reactor development, direct energy conversion was an obvious choice to produce high efficiency electric power generation. Directly capturing the energy of the fission fragments produced during nuclear fission avoids the intermediate conversion to thermal energy and the efficiency limitations of classical thermodynamics. Efficiencies of more than 80% are possible, independent of operational temperature. Direct energy conversion fission reactors would possess a number of unique characteristics that would make them very attractive for commercial power generation. These reactors would be modular in design with integral power conversion and operate at low pressures and temperatures. They would operate at high efficiency and produce power well suited for long distance transmission. They would feature large safety margins and passively safe design. Ideally suited to production by advanced manufacturing techniques, direct energy conversion fission reactors could be produced more economically than conventional reactor designs. The history of direct energy conversion can be considered as dating back to 1913 when Moseleyl demonstrated that charged particle emission could be used to buildup a voltage. Soon after the successful operation of a nuclear reactor, E.P. Wigner suggested the use of fission fragments for direct energy conversion. Over a decade after Wigner's suggestion, the first theoretical treatment of the conversion of fission fragment kinetic energy into electrical potential appeared in the literature. Over the ten years that followed, a number of researchers investigated various aspects of fission fragment direct energy conversion. Experiments were performed that validated the basic physics of the concept, but a variety of technical challenges limited the efficiencies that were achieved. Most research in direct energy conversion ceased in the US by the late 1960s. Sporadic interest in the concept appears in the literature until this day, but there have been no recent significant programs to develop the technology.

  9. DIRECT ENERGY CONVERSION (DEC) FISSION REACTORS - A U.S. NERI PROJECT

    SciTech Connect (OSTI)

    D. BELLER; G. POLANSKY; ET AL

    2000-11-01T23:59:59.000Z

    The direct conversion of the electrical energy of charged fission fragments was examined early in the nuclear reactor era, and the first theoretical treatment appeared in the literature in 1957. Most of the experiments conducted during the next ten years to investigate fission fragment direct energy conversion (DEC) were for understanding the nature and control of the charged particles. These experiments verified fundamental physics and identified a number of specific problem areas, but also demonstrated a number of technical challenges that limited DEC performance. Because DEC was insufficient for practical applications, by the late 1960s most R&D ceased in the US. Sporadic interest in the concept appears in the literature until this day, but there have been no recent programs to develop the technology. This has changed with the Nuclear Energy Research Initiative that was funded by the U.S. Congress in 1999. Most of the previous concepts were based on a fission electric cell known as a triode, where a central cathode is coated with a thin layer of nuclear fuel. A fission fragment that leaves the cathode with high kinetic energy and a large positive charge is decelerated as it approaches the anode by a charge differential of several million volts, it then deposits its charge in the anode after its kinetic energy is exhausted. Large numbers of low energy electrons leave the cathode with each fission fragment; they are suppressed by negatively biased on grid wires or by magnetic fields. Other concepts include magnetic collimators and quasi-direct magnetohydrodynamic generation (steady flow or pulsed). We present the basic principles of DEC fission reactors, review the previous research, discuss problem areas in detail and identify technological developments of the last 30 years relevant to overcoming these obstacles. A prognosis for future development of direct energy conversion fission reactors will be presented.

  10. Study of dissipative dynamics in fission of hot nuclei using Langevin equation

    E-Print Network [OSTI]

    Gargi Chaudhuri

    2004-11-01T23:59:59.000Z

    The fission of highly excited compound nuclei formed in heavy ion induced fusion reactions has emerged as a topic of considerable interest in the recent years. Dissipative dynamical models based on the Langevin equation were developed and were applied successfully for fission dynamics of highly excited heavy nuclei. However, Wall Friction(WF), the standard version of nuclear friction when incorporated in the Langevin dynamical model was not able to reproduce simultaneously experimental data for both prescission neutron multiplicity and fission probability. Consequently, an empirical reduction in the strength of the wall friction was found necessary to reproduce the experimental numbers by many workers. Interestingly, a modification of the wall friction was proposed recently where the reduction was achieved microscopically. This modified version is known as the chaos weighted wall friction(CWWF) which takes into account non-integrability of single particle motion. The work in my thesis aims at using this strongly shape dependent version of friction (CWWF) in the Langevin dynamical model coupled with particle and gamma evaporation in order to verify to what extent it can account for the experimental data of fission of hot nuclei. The experimental data includes excitation functions of prescission neutron multiplicity, fission probability as well as evaporation residue cross-section of a number of nuclei. The importance of transients in nuclear fission is also discussed. The present endeavour is an effort to obtain a clear physical picture of nuclear dissipation which in turn will help in solving many open problems related to collective motion, and in particular, nuclear fission.

  11. GPU COMPUTING FOR PARTICLE TRACKING

    SciTech Connect (OSTI)

    Nishimura, Hiroshi; Song, Kai; Muriki, Krishna; Sun, Changchun; James, Susan; Qin, Yong

    2011-03-25T23:59:59.000Z

    This is a feasibility study of using a modern Graphics Processing Unit (GPU) to parallelize the accelerator particle tracking code. To demonstrate the massive parallelization features provided by GPU computing, a simplified TracyGPU program is developed for dynamic aperture calculation. Performances, issues, and challenges from introducing GPU are also discussed. General purpose Computation on Graphics Processing Units (GPGPU) bring massive parallel computing capabilities to numerical calculation. However, the unique architecture of GPU requires a comprehensive understanding of the hardware and programming model to be able to well optimize existing applications. In the field of accelerator physics, the dynamic aperture calculation of a storage ring, which is often the most time consuming part of the accelerator modeling and simulation, can benefit from GPU due to its embarrassingly parallel feature, which fits well with the GPU programming model. In this paper, we use the Tesla C2050 GPU which consists of 14 multi-processois (MP) with 32 cores on each MP, therefore a total of 448 cores, to host thousands ot threads dynamically. Thread is a logical execution unit of the program on GPU. In the GPU programming model, threads are grouped into a collection of blocks Within each block, multiple threads share the same code, and up to 48 KB of shared memory. Multiple thread blocks form a grid, which is executed as a GPU kernel. A simplified code that is a subset of Tracy++ [2] is developed to demonstrate the possibility of using GPU to speed up the dynamic aperture calculation by having each thread track a particle.

  12. DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD OCTOBER 1, 2001 THROUGH DECEMBER 31, 2002

    SciTech Connect (OSTI)

    L.C. BROWN

    2003-04-07T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD OCTOBER 1, 2001 THROUGH DECEMBER 31, 2002

  13. Singlet-Fission Sensitizers for Ultra-High Efficiency Excitonic Solar Cells: 15 August 2005 - 14 October 2008

    SciTech Connect (OSTI)

    Michl, J.

    2008-12-01T23:59:59.000Z

    We have considered the potential benefits offered by using singlet fission sensitizers in photovoltaic cells and identified two key issues involved in the search for such sensitizers.

  14. Time delays in heavy-ion-induced fission of medium-Z nuclei, measured by crystal blocking

    SciTech Connect (OSTI)

    Andersen, J. U. [Aarhus University; Chevallier, J. [University of Aarhus, Denmark; Forster, J. S. [Universite de Montreal; Karamian, S. A. [FLNR-JINR, Russia; Vane, C Randy [ORNL; Beene, James R [ORNL; Gross, Carl J [ORNL; Krause, Herbert F [ORNL; Liang, J Felix [ORNL; Shapira, Dan [ORNL; Uguzzoni, A. [University of Bologna

    2012-01-01T23:59:59.000Z

    Time delays in fission induced by bombardment of Mo with 170- and 180-MeV {sup 32}S, 225- and 240-MeV {sup 48}Ti, and 300-MeV {sup 58}Ni have been measured by observation of crystal blocking of fission fragments. In contrast to earlier measurements with a W target, the results are consistent with fission of a compound nucleus in competition with mainly neutron emission. Most of the fissions happen on a time scale much shorter than attoseconds but there is a significant component of fission with much longer lifetimes. The measurements are reproduced with a standard statistical model, including a Kramers correction to fission widths from the viscosity of hot nuclear matter. These new results support the interpretation of our earlier measurements with a W target, which indicate that there is a transition in heavy-ion-induced fission at large atomic number and mass, from multichance fission in the standard Bohr-Wheeler picture to fission without formation of a compound nucleus. The process is slowed down by nuclear viscosity, with measured delays of order attoseconds.

  15. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000

    SciTech Connect (OSTI)

    LC BROWN

    2000-02-29T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000

  16. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD OCTOBER 1,2001 THROUGH DECEMBER 31,2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2001-12-31T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD OCTOBER 1,2001 THROUGH DECEMBER 31,2001

  17. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,2000 THROUGH FEBRUARY 28,2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2000-02-28T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,2000 THROUGH FEBRUARY 28,2001

  18. DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD AUGUST 15,2000 THROUGH SEPTEMBER 30,2001

    SciTech Connect (OSTI)

    L.C. BROWN

    2002-02-01T23:59:59.000Z

    OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD AUGUST 15,2000 THROUGH SEPTEMBER 30,2001

  19. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    of Con- trolled Nuclear Fusion, CONF-760975-P3, pages 1061–more effective solution, nuclear fusion. Fission Energy Thethe development of nuclear fusion weapons, humankind has

  20. Test of the adequacy of using smoothly joined parabolic segments to parametrize the multihumped fission barriers in actinides

    SciTech Connect (OSTI)

    Bhandari, B.S. (Department of Physics, Faculty of Science, University of Garyounis, Benghazi (Libya))

    1990-10-01T23:59:59.000Z

    The adequacy of using smoothly joined parabolic segments to parametrize the multihumped fission barriers has been tested by examining its simultaneous consistency with the three relevant fission observables, namely, the near-barrier fission cross sections, isomeric half-lives, and the ground-state spontaneous fission half-lives of a wide variety of a total of 25 actinide nuclides. The penetrabilities through such multihumped fission barriers have been calculated in the Wentzel-Kramers-Brillouin approximation, and the various fission half-lives have been determined using the formalism given earlier by Nix and Walker. The results of our systematic analysis of these actinide nuclides suggest that such a parametrization is quite adequate at least for the even-even nuclei, as it reproduces satisfactorily their various observed fission characteristics. Major difficulties remain, however, for the odd mass and for the doubly odd nuclei where the calculated ground-state spontaneous fission half-lives are found to be several orders of magnitude larger than those measured. Possible reasons for such discrepancies are discussed. Fission branching ratios of the decay of the shape isomers in various actinide nuclides have also been calculated and are compared with their measured values.

  1. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    DT Deuterium-Tritium DU Depleted Uranium FIMA Fission ofengine loaded with depleted uranium. In Proc. PHYSOR 2010,fuel layer comprised of depleted uranium contained in

  2. Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np

    SciTech Connect (OSTI)

    Hoff, R.W.

    1988-02-19T23:59:59.000Z

    Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age must be considered more uncertain than if the calculated rates of beta-delayed fission were found to be acceptable. The nuclear level structure of 238Np has been investigated using the 237Np(n,..gamma..)238Np reaction and the alpha decay of 242mAm as experimental probes. Having established a level scheme for 238Np that includes 47 excited levels and 93 secondary transitions, we find a high degree of correspondence between the experimental band structure and that of a semi-empirical model developed to predict excitations in odd-odd deformed nuclei. 35 refs., 4 figs., 3 tabs.

  3. ORO Office Safeguards and Security Clearance Tracking System...

    Energy Savers [EERE]

    Office Safeguards and Security Clearance Tracking System and Visitor Control System PIA, Oak Ridge Operations Office ORO Office Safeguards and Security Clearance Tracking System...

  4. High Efficiency Broadband Envelope-Tracking Power Amplifiers

    E-Print Network [OSTI]

    Yan, Jonmei Johana

    17] Bumman, K. , et.al; "Efficiently Amplified," MicrowaveM. ,   “   Wideband High Efficiency Envelope Tracking PowerPeter  M. ,  “High-Efficiency Envelope Tracking High Power

  5. Enhancements to System for Tracking Radioactive Waste Shipments...

    Energy Savers [EERE]

    Multiple Users January 30, 2013 - 12:00pm Addthis Transportation Tracking and Communication System users can now track shipments of radioactive materials and access...

  6. Spatially tracking 13C labeled substrate (bicarbonate) accumulation...

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

    tracking 13C labeled substrate (bicarbonate) accumulation in microbial communities using laser ablation isotope ratio Spatially tracking 13C labeled substrate (bicarbonate)...

  7. Extracting and Using Data From Tracking Systems | Department...

    Energy Savers [EERE]

    Extracting and Using Data From Tracking Systems Extracting and Using Data From Tracking Systems Better Buildings Neighborhood Program Data and Evaluation Peer Exchange Call:...

  8. Secure Program Execution Via Dynamic Information Flow Tracking

    E-Print Network [OSTI]

    Suh, G. Edward

    2003-07-21T23:59:59.000Z

    We present a simple architectural mechanism called dynamicinformation flow tracking that can significantly improve thesecurity of computing systems with negligible performanceoverhead. Dynamic information flow tracking ...

  9. High Efficiency Broadband Envelope-Tracking Power Amplifiers

    E-Print Network [OSTI]

    Yan, Jonmei Johana

    M. ,   “   Wideband High Efficiency Envelope Tracking PowerPeter  M. ,  “High-Efficiency Envelope Tracking High PowerMemory! DPD! Drain! Efficiency! (%)! Gain! (dB)! Output!

  10. Fission Yield Measurements from Highly Enriched Uranium Irradiated Inside a Boron Carbide Capsule

    SciTech Connect (OSTI)

    Metz, Lori A.; Friese, Judah I.; Finn, Erin C.; Greenwood, Lawrence R.; Kephart, Rosara F.; Hines, Corey C.; King, Matthew D.; Henry, Kelley; Wall, Donald E.

    2013-05-01T23:59:59.000Z

    A boron carbide capsule was previously designed and tested by Pacific Northwest National Laboratory (PNNL) and Washington State University (WSU) for spectral-tailoring in mixed spectrum reactors. The presented work used this B4C capsule to create a fission product sample from the irradiation of highly enriched uranium (HEU) with a fast fission neutron spectrum. An HEU foil was irradiated inside of the capsule in WSU’s 1 MW TRIGA reactor at full power for 200 min to produce 5.8 × 1013 fissions. After three days of cooling, the sample was shipped to PNNL for radiochemical separations and analysis by gamma and beta spectroscopy. Fission yields for products were calculated from the radiometric measurements and compared to measurements from thermal neutron induced fission (analyzed in parallel with the non-thermal sample at PNNL) and published evaluated fast-pooled and thermal nuclear data. Reactor dosimetry measurements were also completed to fully characterize the neutron spectrum and total fluence of the irradiation.

  11. A fission matrix based validation protocol for computed power distributions in the advanced test reactor

    SciTech Connect (OSTI)

    Nielsen, J. W. [Idaho National Laboratory, MS 3840, PO Box 1625, Idaho Falls, ID 83415 (United States); Nigg, D. W. [Idaho National Laboratory, MS 3860, PO Box 1625, Idaho Falls, ID 83415 (United States); LaPorta, A. W. [Idaho National Laboratory, MS 7136, PO Box 1625, Idaho Falls, ID 83415 (United States)

    2013-07-01T23:59:59.000Z

    The Idaho National Laboratory (INL) has been engaged in a significant multi year effort to modernize the computational reactor physics tools and validation procedures used to support operations of the Advanced Test Reactor (ATR) and its companion critical facility (ATRC). Several new protocols for validation of computed neutron flux distributions and spectra as well as for validation of computed fission power distributions, based on new experiments and well-recognized least-squares statistical analysis techniques, have been under development. In the case of power distributions, estimates of the a priori ATR-specific fuel element-to-element fission power correlation and covariance matrices are required for validation analysis. A practical method for generating these matrices using the element-to-element fission matrix is presented, along with a high-order scheme for estimating the underlying fission matrix itself. The proposed methodology is illustrated using the MCNP5 neutron transport code for the required neutronics calculations. The general approach is readily adaptable for implementation using any multidimensional stochastic or deterministic transport code that offers the required level of spatial, angular, and energy resolution in the computed solution for the neutron flux and fission source. (authors)

  12. Explicit estimation of higher order modes in fission source distribution of Monte-Carlo calculation

    SciTech Connect (OSTI)

    Yamamoto, A.; Sakata, K.; Endo, T. [Nagoya University, Department of Materials, Physics and Energy Engineering, Furo-cho, Chikusa-ku, Nagoya, 464-8603 (Japan)

    2013-07-01T23:59:59.000Z

    Magnitude of higher order modes in fission source distribution of a multi-group Monte-Carlo calculation is estimated using the orthogonal property of forward and adjoint fission source distributions. Calculation capability of the forward and adjoint fission source distributions for fundamental and higher order modes are implemented in the AEGIS code, which is a two-dimensional transport code based on the method of characteristics. With the calculation results of the AEGIS code, magnitudes of the first to fifth higher order modes in fission source distribution obtained by the multi-group Monte-Carlo code GMVP are estimated. There are two contributions in the present study - (1) establishment of a surrogate model, which represents convergence of fission source distribution taking into account the inherent statistical 'noise' of higher order modes of Monte-Carlo calculations and (2) independent confirmation of the estimated dominance ratio in a Monte-Carlo calculation. The surrogate model would contribute to studies of the inter-cycle correlation and estimation of sufficient number of inactive/active cycles. (authors)

  13. New features in the stability and fission decay of superheavy Thorium isotopes

    E-Print Network [OSTI]

    L. Satpathy; S. K. Patra; R. K. Choudhury

    2006-04-12T23:59:59.000Z

    Superheavy isotopes are highly neutron rich nuclei in the vicinity of neutron drip-line, stabilized by shell effect against the instability due to repulsive component of nuclear force, analogous to superheavy elements similarly stabilized against Coulomb instability. Here we discuss the stability and fission decay properties of such nuclei in the $^{254}$Th region and show that they are stable against $\\alpha$ and fission decay and have $\\beta$-decay life time of several tens of seconds. In particular, the $^{254}$Th nucleus has a low fission barrier and unusally large barrier width. This makes it an ideal thermally fissile nucleus, if formed by means of a thermal neutron, like other known nuclei such as $^{233}$U, $^{235}$U, $^{239}$Pu in this actinide region. It shows a new mode of fast fission decay, which may be termed as multifragmentation fission, in which in addition to two heavy fragments large number of scission neutrons are simultaneously produced. Its likely synthesis during the r-process nucleosynthesis will have important bearing on steller evolution, and here in the laboratory, it has great potential in energy production.

  14. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JANUARY 1, 2002 THROUGH MARCH 31, 2002

    SciTech Connect (OSTI)

    L.C. BROWN

    2002-03-31T23:59:59.000Z

    Direct energy conversion is the only potential means for producing electrical energy from a fission reactor without the Carnot efficiency limitations. This project was undertaken by Sandia National Laboratories, Los Alamos National Laboratories, The University of Florida, Texas A&M University and General Atomics to explore the possibilities of direct energy conversion. Other means of producing electrical energy from a fission reactor, without any moving parts, are also within the statement of proposed work. This report documents the efforts of General Atomics. Sandia National Laboratories, the lead laboratory, provides overall project reporting and documentation. The highlights of this reporting period are: (1) Cooling of the vapor core reactor and the MHD generator was incorporated into the Vapor Core Reactor model using standard heat transfer calculation methods. (2) Fission product removal, previously modeled as independent systems for each class of fission product, was incorporated into the overall fuel recycle loop of the Vapor Core Reactor. The model showed that the circulating activity levels are quite low. (3) Material distribution calculations were made for the ''pom-pom'' style cathode for the Fission Electric Cell. Use of a pom-pom cathode will eliminate the problem of hoop stress in the thin spherical cathode caused by the electric field.

  15. Fission-product-release signatures for LWR fuel rods failed during PCM and RIA transients

    SciTech Connect (OSTI)

    Osetek, D.J.; King, J.J.; Croucher, D.W.

    1981-01-01T23:59:59.000Z

    This paper discusses fission product release from light-water-reactor-type fuel rods to the coolant loop during design basis accident tests. One of the tests was a power-cooling-mismatch test in which a single fuel rod was operated in film boiling beyond failure. Other tests discussed include reactivity initiated accident (RIA) tests, in which the fuel rods failed as a result of power bursts that produced radial-average peak fuel enthalpies ranging from 250 to 350 cal/g. One of the RIA tests used two previously irradiated fuel rods. On-line gamma spectroscopic measurements of short-lived fission products, and important aspects of fission product behavior observed during the tests, are discussed. Time-dependent release fractions for short-lived fission products are compared with release fractions suggested by: the Reactor Safety Study; NRC Regulatory Guides; and measurements from the Three Mile Island accident. Iodine behavior observed during the tests is discussed, and fuel powdering is identified as a source of particulate fission product activity, the latter of which is neglected for most accident analyses.

  16. Fission matrix-based Monte Carlo criticality analysis of fuel storage pools

    SciTech Connect (OSTI)

    Farlotti, M. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Ecole Polytechnique, Palaiseau, F 91128 (France); Larsen, E. W. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

    2013-07-01T23:59:59.000Z

    Standard Monte Carlo transport procedures experience difficulties in solving criticality problems in fuel storage pools. Because of the strong neutron absorption between fuel assemblies, source convergence can be very slow, leading to incorrect estimates of the eigenvalue and the eigenfunction. This study examines an alternative fission matrix-based Monte Carlo transport method that takes advantage of the geometry of a storage pool to overcome this difficulty. The method uses Monte Carlo transport to build (essentially) a fission matrix, which is then used to calculate the criticality and the critical flux. This method was tested using a test code on a simple problem containing 8 assemblies in a square pool. The standard Monte Carlo method gave the expected eigenfunction in 5 cases out of 10, while the fission matrix method gave the expected eigenfunction in all 10 cases. In addition, the fission matrix method provides an estimate of the error in the eigenvalue and the eigenfunction, and it allows the user to control this error by running an adequate number of cycles. Because of these advantages, the fission matrix method yields a higher confidence in the results than standard Monte Carlo. We also discuss potential improvements of the method, including the potential for variance reduction techniques. (authors)

  17. Kalman Filter Tracking on Parallel Architectures

    E-Print Network [OSTI]

    Giuseppe Cerati; Peter Elmer; Steven Lantz; Kevin McDermott; Dan Riley; Matevž Tadel; Peter Wittich; Frank Würthwein; Avi Yagil

    2015-05-18T23:59:59.000Z

    Power density constraints are limiting the performance improvements of modern CPUs. To address this we have seen the introduction of lower-power, multi-core processors, but the future will be even more exciting. In order to stay within the power density limits but still obtain Moore's Law performance/price gains, it will be necessary to parallelize algorithms to exploit larger numbers of lightweight cores and specialized functions like large vector units. Example technologies today include Intel's Xeon Phi and GPGPUs. Track finding and fitting is one of the most computationally challenging problems for event reconstruction in particle physics. At the High Luminosity LHC, for example, this will be by far the dominant problem. The need for greater parallelism has driven investigations of very different track finding techniques including Cellular Automata or returning to Hough Transform. The most common track finding techniques in use today are however those based on the Kalman Filter. Significant experience has been accumulated with these techniques on real tracking detector systems, both in the trigger and offline. They are known to provide high physics performance, are robust and are exactly those being used today for the design of the tracking system for HL-LHC. Our previous investigations showed that, using optimized data structures, track fitting with Kalman Filter can achieve large speedup both with Intel Xeon and Xeon Phi. We report here our further progress towards an end-to-end track reconstruction algorithm fully exploiting vectorization and parallelization techniques in a realistic simulation setup.

  18. TRACKING CODE DEVELOPMENT FOR BEAM DYNAMICS OPTIMIZATION

    SciTech Connect (OSTI)

    Yang, L.

    2011-03-28T23:59:59.000Z

    Dynamic aperture (DA) optimization with direct particle tracking is a straight forward approach when the computing power is permitted. It can have various realistic errors included and is more close than theoretical estimations. In this approach, a fast and parallel tracking code could be very helpful. In this presentation, we describe an implementation of storage ring particle tracking code TESLA for beam dynamics optimization. It supports MPI based parallel computing and is robust as DA calculation engine. This code has been used in the NSLS-II dynamics optimizations and obtained promising performance.

  19. Class 3 Tracking and Monitoring System Report

    SciTech Connect (OSTI)

    Safely, Eugene; Salamy, S. Phillip

    1999-11-29T23:59:59.000Z

    The objective of Class 3 tracking system are to assist DOE in tracking and performance and progress of these projects and to capture the technical and financial information collected during the projects' monitoring phase. The captured information was used by DOE project managers and BDM-Oklahoma staff for project monitoring and evaluation, and technology transfer activities. The proposed tracking system used the Class Evaluation Executive Report (CLEVER), a relation database for storing and disseminating class project data; GeoGraphix, a geological and technical analysis and mapping software system; the Tertiary Oil Recovery Information System (TORIS) database; and MS-Project, a project management software system.

  20. Insights On The Thermal History Of The Valles Caldera, New Mexico...

    Open Energy Info (EERE)

    Insights On The Thermal History Of The Valles Caldera, New Mexico- Evidence From Zircon Fission-Track Analysis Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  1. Magnetic Field Generation in Planets and Satellites by Natural Nuclear Fission Reactors

    E-Print Network [OSTI]

    J. Marvin Herndon

    2007-09-27T23:59:59.000Z

    One of the most fundamental problems in physics has been to understand the nature of the mechanism that generates the geomagnetic field and the magnetic fields of other planets and satellites. For decades, the dynamo mechanism, thought to be responsible for generating the geomagnetic field and other planetary magnetic fields, has been ascribed to convection in each planet's iron-alloy core. Recently, I described the problems inherent in Earth-core convection and proposed instead that the geomagnetic field is produced by a dynamo mechanism involving convection, not in the fluid core, but in the electrically conductive, fluid, fission-product sub-shell of a natural nuclear fission reactor at the center of the Earth, called the georeactor. Here I set forth in detail the commonality in the Solar System of the matter like that of the inside of the Earth, which is my basis for generalizing the concept of planetary magnetic field generation by natural planetocentric nuclear fission reactors.

  2. Study of dissipative dynamics in fission of hot nuclei using Langevin equation

    E-Print Network [OSTI]

    Chaudhuri, G

    2004-01-01T23:59:59.000Z

    The fission of highly excited compound nuclei formed in heavy ion induced fusion reactions has emerged as a topic of considerable interest in the recent years. Dissipative dynamical models based on the Langevin equation were developed and were applied successfully for fission dynamics of highly excited heavy nuclei. However, Wall Friction(WF), the standard version of nuclear friction when incorporated in the Langevin dynamical model was not able to reproduce simultaneously experimental data for both prescission neutron multiplicity and fission probability. Consequently, an empirical reduction in the strength of the wall friction was found necessary to reproduce the experimental numbers by many workers. Interestingly, a modification of the wall friction was proposed recently where the reduction was achieved microscopically. This modified version is known as the chaos weighted wall friction(CWWF) which takes into account non-integrability of single particle motion. The work in my thesis aims at using this stron...

  3. A comparison between the fission matrix method, the diffusion model and the transport model

    SciTech Connect (OSTI)

    Dehaye, B.; Hugot, F. X.; Diop, C. M. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Direction de l'Energie Nucleaire, Departement de Modelisation des Systemes et Structures, CEA DEN/DM2S, PC 57, F-91191 Gif-sur-Yvette cedex (France)

    2013-07-01T23:59:59.000Z

    The fission matrix method may be used to solve the critical eigenvalue problem in a Monte Carlo simulation. This method gives us access to the different eigenvalues and eigenvectors of the transport or fission operator. We propose to compare the results obtained via the fission matrix method with those of the diffusion model, and an approximated transport model. To do so, we choose to analyse the mono-kinetic and continuous energy cases for a Godiva-inspired critical sphere. The first five eigenvalues are computed with TRIPOLI-4{sup R} and compared to the theoretical ones. An extension of the notion of the extrapolation distance is proposed for the modes other than the fundamental one. (authors)

  4. Delayed neutron noise characteristics of an in-pile fission product loop

    SciTech Connect (OSTI)

    Tamaoki, T. (Toshiba Corp., Nuclear Engineering Lab., 8 Shin-Sugita, Isogo-ku, Yokohama 235 (JP)); Sakai, T.; Endo, H. (Toshiba Corp., Isogo Engineering Center, 8 Shin-Sugita, Isogo-ku, Yokohama 235 (JP)); Haga, K. (Power Reactor and Nuclear Fuel Development Corp., O-aral Engineering Center, 4002 Narita, O-araimachi, Ibaraki-ken 311-13 (JP)); Takahashi, R. (Tokyo Inst. of Technology, Dept. of Mechanical Engineering, Ookayama, Meguro-ku, Tokyo 152 (JP))

    1992-07-01T23:59:59.000Z

    This paper reports on delayed neutron noise measurements carried out in an in-pile sodium loop, the Fission Product Loop 2 (FPL-2), installed on the Toshiba Training Reactor I. To clarify the characteristics and origin of delayed neutron count rate noise, a noise propagation mechanism was identified using a multivariate autoregressive model. The results show that a simulated fuel failure in the FPL-2, with recoil as the principal fission product release phenomena, produces a white spectrum of delayed neutron count rate noise. It was also found that the loop temperature fluctuation strongly affects the delayed neutron count rate noise at temperatures below 300{degrees} C, through the deposition of fission products on the surface of structures.

  5. Fission induced swelling and creep of U–Mo alloy fuel

    SciTech Connect (OSTI)

    Yeon Soo Kim; G. L. Hofman; J. S. Cheon; A. B. Robinson; D. M. Wachs

    2013-06-01T23:59:59.000Z

    Tapering of U–Mo alloy fuel at the end of plates is attributed to lateral mass transfer by fission induced creep, by which fuel mass is relocated away from the fuel end region where fission product induced fuel swelling is in fact the highest. This mechanism permits U–Mo fuel to achieve high burnup by effectively relieving stresses at the fuel end region, where peak stresses are otherwise expected because peak fission product induced fuel swelling occurs there. ABAQUS FEA was employed to examine whether the observed phenomenon can be simulated using physical–mechanical data available in the literature. The simulation results obtained for several plates with different fuel fabrication and loading scheme showed that the measured data were able to be simulated with a reasonable creep rate coefficient. The obtained creep rate constant lies between values for pure uranium and MOX, and is greater than all other ceramic uranium fuels.

  6. Nucleation and cluster formation in low-density nucleonic matter: A mechanism for ternary fission

    E-Print Network [OSTI]

    S. Wuenschel; H. Zheng; K. Hagel; B. Meyer; M. Barbui; E. J. Kim; G. Roepke; J. B. Natowitz

    2014-06-20T23:59:59.000Z

    Ternary fission yields in the reaction 241Pu(nth,f) are calculated using a new model which assumes a nucleation-time moderated chemical equilibrium in the low density matter which constitutes the neck region of the scissioning system. The temperature, density, proton fraction and fission time required to fit the experimental data are derived and discussed. A reasonably good fit to the experimental data is obtained. This model provides a natural explanation for the observed yields of heavier isotopes relative to those of the lighter isotopes, the observation of low proton yields relative to 2H and 3H yields and the non-observation of 3He, all features which are shared by similar thermal neutron induced and spontaneous fissioning systems.

  7. TRISO Fuel Performance: Modeling, Integration into Mainstream Design Studies, and Application to a Thorium-fueled Fusion-Fission Hybrid Blanket

    E-Print Network [OSTI]

    Powers, Jeffrey

    2011-01-01T23:59:59.000Z

    of a Hybrid Fusion-Fission Nuclear Energy System. ” Thesis.hybrid fusion-fission Laser Inertial Fusion-based Energy (LIFE) systems.Hybrid LIFE Engines Laser Inertial Fusion-based Energy (LIFE) systems

  8. True ternary fission, the collinear cluster tripartition (CCT) of {sup 252}Cf

    SciTech Connect (OSTI)

    Oertzen, W. von; Pyatkov, Y. V.; Kamanin, D. [Helmholtz Zentrum, D14109 Berlin (Germany); Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Moscow region (Russian Federation); Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Moscow region (Russian Federation) and Helmholtz Zentrum, D14109 Berlin (Germany)

    2012-10-20T23:59:59.000Z

    In systematic work over the last decade (see Pyatkov et al. [12] and refs therein), the ternary fission decay of heavy nuclei, in {sup 235}U(n,fff) and {sup 252}Cf(sf) has been studied in a collinear geometry. The name used for this process is (CCT), with three fragments of similar size in a collinear decay, it is the true ternary fission. This decay has been observed in spontaneous fission as well as in a neutron induced reaction. The measurements are based on different experimental set-ups, with binary coincidences containing TOF and energy determinations. With two detector telescopes placed at 180 Degree-Sign , the measurements of masses and energies of each of the registered two fragments, give complete kinematic solutions. Thus the missing mass events in binary coincidences can be determined, these events are obtained by blocking one of the lighter fragments on a structure in front of the detectors. The relatively high yield of CCT (more than 10{sup -3} per binary fission) is explained. It is due to the favourable Q-values (more positive than for binary) and the large phase space of the ternary CCT-decay, dominated by three (magic) clusters: e.g. isotopes of Sn, Ca and Ni, {sup 132}Sn+{sup 50}Ca+{sup 70}Ni. It is shown that the collinear (prolate) geometry has the favoured potential energy relative to the oblate shapes. The ternary fission is considered to be a sequential process. With this assumption the kinetic energies of the fragments have been calculated by Vijay et al.. The third fragments have very low kinetic energies (below 20 MeV) and have thus escaped their detection in previous work on 'ternary fission', where in addition an oblate shape and a triangle for the momentum vectors have been assumed.

  9. Fission-Fusion: A new reaction mechanism for nuclear astrophysics based on laser-ion acceleration

    SciTech Connect (OSTI)

    Thirolf, P. G.; Gross, M.; Allinger, K.; Bin, J.; Henig, A.; Kiefer, D. [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-85748 Garching (Germany); Habs, D. [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Ma, W.; Schreiber, J. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany)

    2011-10-28T23:59:59.000Z

    We propose to produce neutron-rich nuclei in the range of the astrophysical r-process around the waiting point N = 126 by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a CH{sub 2} layer), where the light fission fragments of the beam fuse with the light fission fragments of the target. Via the 'hole-boring' mode of laser Radiation Pressure Acceleration using a high-intensity, short pulse laser, very efficiently bunches of {sup 232}Th with solid-state density can be generated from a Th target and a deuterated CD{sub 2} foil, both forming the production target assembly. Laser-accelerated Th ions with about 7 MeV/u will pass through a thin CH{sub 2} layer placed in front of a thicker second Th foil (both forming the reaction target) closely behind the production target and disintegrate into light and heavy fission fragments. In addition, light ions (d,C) from the CD{sub 2} layer of the production target will be accelerated as well, inducing the fission process of {sup 232}Th also in the second Th layer. The laser-accelerated ion bunches with solid-state density, which are about 10{sup 14} times more dense than classically accelerated ion bunches, allow for a high probability that generated fission products can fuse again. The high ion beam density may lead to a strong collective modification of the stopping power, leading to significant range and thus yield enhancement. Using a high-intensity laser as envisaged for the ELI-Nuclear Physics project in Bucharest (ELI-NP), order-of-magnitude estimates promise a fusion yield of about 10{sup 3} ions per laser pulse in the mass range of A = 180-190, thus enabling to approach the r-process waiting point at N = 126.

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

    SciTech Connect (OSTI)

    J M Harp; P D Demkowicz; S A Ploger

    2012-10-01T23:59:59.000Z

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

  11. New Fission-Product Waste Forms: Development and Characterization

    SciTech Connect (OSTI)

    Alexandra Navrotsky

    2010-07-30T23:59:59.000Z

    Research performed on the program “New Fission Product Waste Forms: Development and Characterization,” in the last three years has fulfilled the objectives of the proposal which were to 1) establish ceramic waste forms for disposing of Cs, Sr and minor actinides, 2) fully characterize the phase relationships, structures and thermodynamic and kinetic stabilities of promising waste forms, 3) establish a sound technical basis for understanding key waste form properties, such as melting temperatures and aqueous durability, based on an in-depth understanding of waste form structures and thermochemistry, and 4) establish synthesis, testing, scaleup and commercialization routes for wasteform implementation through out in-kind collaborations. In addition, since Cs and Sr form new elements by radioactive decay, the behavior and thermodynamics of waste forms containing different proportions of Cs, Sr and their decay products were discovered using non-radioactive analogues. Collaborations among researchers from three institutions, UC Davis, Sandia National Laboratories, and Shott Inc., were formed to perform the primary work on the program. The unique expertise of each of the members in the areas of waste form development, structure/property relationships, hydrothermal and high temperature synthesis, crystal/glass production, and thermochemistry was critical to program success. In addition, collaborations with the Brigham Young Univeristy, Ben Gurion University, and Los Alamos National Laboratory, were established for standard entropies of ceramic waste forms, sol-gel synthesis, and high temperature synthesis. This work has had a significant impact in a number of areas. First, the studies of the thermodynamic stability of the mineral analogues provided an important technical foundation for assessment the viability of multicomponent oxide phases for Cs and Sr removal. Moreover, the thermodynamic data discovered in this program established information on the reaction pathways for the potential reaction products. The phase equilibria and thermodynamics involving the intermediates in the decay process in this program will assist in selection of the best process for Cs or Sr immobilization. In addition, data from the study can be used to develop engineering solutions for potential process upsets. Second, the glass – crystal stability of multicomponent oxide phases that were representative silicates on this program is highly distinguishable for mother compounds and decay products, thus providing a fundamental understanding on the separate effects from chemistry and from radiation. Finally, we have developed a foundation for understanding chemistry-structure-energetics relationships in titanosilicates that can be used to develop more effective materials.

  12. Nuclear Instruments and Methods in Physics Research A 554 (2005) 494499 Micro-pocket fission detectors (MPFD) for

    E-Print Network [OSTI]

    Shultis, J. Kenneth

    2005-01-01T23:59:59.000Z

    Nuclear Instruments and Methods in Physics Research A 554 (2005) 494­499 Micro-pocket fission, A.S.M. Sabbir Ahmed, J. Kenneth Shultis S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Available online 18 August 2005 Abstract Micro-pocket fission detectors (MPFD) have been fabricated

  13. NUCLEAR SCIENCE AND ENGINEERING: 124, 482-491 (1996) Fission Cross-Section Measurements of the Odd-Odd

    E-Print Network [OSTI]

    Danon, Yaron

    1996-01-01T23:59:59.000Z

    NUCLEAR SCIENCE AND ENGINEERING: 124, 482-491 (1996) Fission Cross-Section Measurements of the Odd-Odd Isotopes 232Pa, 238Np, and 236Np Y. Danon* Rensselaer Polytechnic Institute, Department of Nuclear, 1995 Accepted March 9, 1996 Abstract- Transmutation ofactinide waste into fission products could

  14. NUCLEAR SCIENCE AND ENGINEERING: 109, 341-349 (1991) Fission Cross-Section Measurements of 247Cm,

    E-Print Network [OSTI]

    Danon, Yaron

    1991-01-01T23:59:59.000Z

    -- NUCLEAR SCIENCE AND ENGINEERING: 109, 341-349 (1991) Fission Cross-Section Measurements of 247Cm Polytechnic Institute, Department of Nuclear Engineering and Engineering Physics Gaerttner Linac Laboratory Alamos, New Mexico 87451 Received September 21, 1990 Accepted June 4, 1991 Abstract- The fission cross

  15. Measurement of Prompt Fission Neutron Spectrum Using a Gamma Tagging Method E. Blain, A. Daskalakis, Y. Danon

    E-Print Network [OSTI]

    Danon, Yaron

    uncertainties in these values can have significant impact on the uncertainty associated with reactor criticality correspond to up to a 4% uncertainty on keff for various systems including both fast and light water systems fission chamber which uses the energy deposited by fission fragments in a fill gas to determine

  16. Relative yields of U-235 fission products measured in a high level radioactive sludge at Savannah River Site

    SciTech Connect (OSTI)

    Bibler, N.E.; Coleman, C.J. [Westinghouse Savannah River Co., Aiken, SC (United States); Kinard, W.F. [Charleston Coll., SC (United States). Dept. of Chemistry

    1992-10-01T23:59:59.000Z

    This paper presents measurements of the concentrations of 42 of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at Savannah River Site. The 42 fision products make up 98% of the waste sludge. We used inductively coupled plasma-mass spectroscopy for the analysis. The relative yields for most of the fission products are in complete agreement with the known relative yields for the beta decay chains of the two asymmetric branches of the slow neutron fission of U-235. Disagreements can be reconciled based on the chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses. This paper presents measurements of the concentrations of 42 (98%) of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at the Savannah River Site. We analyzed the sludge with inductively coupled plasma-mass spectroscopy. The relative yields for most of the fission products agree completely with the known relative vields for the beta decay chains of the two asymmetric: branches of the slow neutron fission of U-235. The chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses explain the differences in the measured and calculated results.

  17. Relative yields of U-235 fission products measured in a high level radioactive sludge at Savannah River Site

    SciTech Connect (OSTI)

    Bibler, N.E.; Coleman, C.J. (Westinghouse Savannah River Co., Aiken, SC (United States)); Kinard, W.F. (Charleston Coll., SC (United States). Dept. of Chemistry)

    1992-01-01T23:59:59.000Z

    This paper presents measurements of the concentrations of 42 of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at Savannah River Site. The 42 fision products make up 98% of the waste sludge. We used inductively coupled plasma-mass spectroscopy for the analysis. The relative yields for most of the fission products are in complete agreement with the known relative yields for the beta decay chains of the two asymmetric branches of the slow neutron fission of U-235. Disagreements can be reconciled based on the chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses. This paper presents measurements of the concentrations of 42 (98%) of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at the Savannah River Site. We analyzed the sludge with inductively coupled plasma-mass spectroscopy. The relative yields for most of the fission products agree completely with the known relative vields for the beta decay chains of the two asymmetric: branches of the slow neutron fission of U-235. The chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses explain the differences in the measured and calculated results.

  18. Probabilities for the emission of light particles and their energy and angular distributions for true quaternary nuclear fission

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru; Titova, L. V. [Voronezh State University (Russian Federation)] [Voronezh State University (Russian Federation)

    2013-01-15T23:59:59.000Z

    On the basis of quantum-mechanical fission theory, the features of true quaternary nuclear fission are studied by treating this fission process as a sequence of three processes following one another in the course of time. The first two processes are the escape of the first and then the second of the two light particles emitted from the neck of a fissioning nucleus because of a nonadiabatic character of the collective deformation motion of this nucleus. Finally, the third process is the separation of the fissioning nucleus into two rather heavy fission fragments. The differences that arise in the emission probabilities and in the angular and energy distributions upon going over from the first emitted to the second emitted prescission third and fourth particles are analyzed by invoking experimental data on the spontaneous and thermalneutron-induced fission of nuclei, and it is shown that these differences are caused by the changes both in the geometric configuration of the fissioning nucleus and in the shell structure of its neck after the first prescission particle is emitted from it.

  19. Innovative Mobile Technologies for Asset Tracking 

    E-Print Network [OSTI]

    Liko, W.

    2013-01-01T23:59:59.000Z

    ICEBO Session 15 - Innovative Mobile Technologies for Asset Tracking Agenda ? Learn how clients have mobilized their enterprise data to increase the consistent capture and reporting of important building information, from lease data to work...

  20. Alpha track density using a semiconductor detector

    E-Print Network [OSTI]

    Hamilton, Ian Scott

    1993-01-01T23:59:59.000Z

    of factors including variation in the initial dielectric thickness, and other undefined parameters. In addition, the resultant radon concentration reading is dependent upon the calibration factor used to interpret the track density reading. Obtaining...

  1. Comparison of Current LCD Tracking Options

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Comparison of Current LCD Tracking Options Bruce Schumm Santa Cruz Institute for Particle Physics for new S design (pattern recognition, resolution) S detector in real trouble at low angle w/out beam

  2. Experiments with Underwater Robot Localization and Tracking

    E-Print Network [OSTI]

    Corke, Peter; Detwiler, Carrick; Dunbabin, Matthew; Hamilton, Michael; Rus, Daniela; Vasilescu, Iuliu

    2007-01-01T23:59:59.000Z

    survey part 2: Vision-based station-keeping and positioning,” Journal of Marine Design and Operations,survey part 1: Vision-based cable-, pipeline-, and ?sh tracking,” Journal of Marine Design and Operations,

  3. A study of the almost sequential mechanism of true ternary fission

    E-Print Network [OSTI]

    Tashkhodjaev, R B; Nasirov, A K; von Oertzen, W; Oh, Yongseok

    2015-01-01T23:59:59.000Z

    We consider the collinear ternary fission which is a sequential ternary decay with a very short time between the ruptures of two necks connecting the middle cluster of the ternary nuclear system and outer fragments. In particular, we consider the case where the Coulomb field of the first massive fragment separated during the first step of the fission produces a lower pre-scission barrier in the second step of the residual part of the ternary system. In this case, we obtain a probability of about $10^{-3}$ for the yield of massive clusters such as \

  4. Target and method for the production of fission product molybdenum-99

    DOE Patents [OSTI]

    Vandegrift, G.F.; Vissers, D.R.; Marshall, S.L.; Varma, R.

    1987-10-26T23:59:59.000Z

    A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm/sup 2/ of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99. 2 figs.

  5. Critical temperature for the nuclear liquid-gas phase transition (from multifragmentation and fission)

    E-Print Network [OSTI]

    V. A. Karnaukhov; H. Oeschler; A. Budzanowski; S. P. Avdeyev; A. S. Botvina; E. A. Cherepanov; W. Karcz; V. V. Kirakosyan; P. A. Rukoyatkin; I. Skwirczynska; E. Norbeck

    2008-01-29T23:59:59.000Z

    Critical temperature Tc for the nuclear liquid-gas phase transition is stimated both from the multifragmentation and fission data. In the first case,the critical temperature is obtained by analysis of the IMF yields in p(8.1 GeV)+Au collisions within the statistical model of multifragmentation (SMM). In the second case, the experimental fission probability for excited 188Os is compared with the calculated one with Tc as a free parameter. It is concluded for both cases that the critical temperature is higher than 16 MeV.

  6. Study of asymmetric fission yield behavior from neutron-deficient Hg isotope

    SciTech Connect (OSTI)

    Perkasa, Y. S. [Department of Physics, Sunan Gunung Djati State Islamic University Bandung, Jl. A.H Nasution No. 105 Cibiru, Bandung (Indonesia); Waris, A., E-mail: awaris@fi.itb.ac.id; Kurniadi, R., E-mail: awaris@fi.itb.ac.id; Su'ud, Z., E-mail: awaris@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesa No. 10 Bandung 40132 (Indonesia)

    2014-09-30T23:59:59.000Z

    A study of asymmetric fission yield behavior from a neutron-deficient Hg isotope has been conducted. The fission yield calculation of the neutron-deficient Hg isotope using Brownian Metropolis shape had showed unusual result at decreasing energy. In this paper, this interesting feature will be validated by using nine degree of scission shapes parameterization from Brosa model that had been implemented in TALYS nuclear reaction code. This validation is intended to show agreement between both model and the experiment result. The expected result from these models considered to be different due to dynamical properties that implemented in both models.

  7. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JULY 1, 2002 THROUGH SEPTEMBER 30, 2002

    SciTech Connect (OSTI)

    L.C. BROWN

    2002-09-30T23:59:59.000Z

    Direct energy conversion is the only potential means for producing electrical energy from a fission reactor without the Carnot efficiency limitations. This project was undertaken by Sandia National Laboratories, Los Alamos National Laboratories, The University of Florida, Texas A&M University and General Atomics to explore the possibilities of direct energy conversion. Other means of producing electrical energy from a fission reactor, without any moving parts, are also within the statement of proposed work. This report documents the efforts of General Atomics. Sandia National Laboratories, the lead laboratory, provides overall project reporting and documentation.

  8. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD APRIL 1, 2002 THROUGH JUNE 30, 2002

    SciTech Connect (OSTI)

    L.C. BROWN

    2002-06-30T23:59:59.000Z

    Direct energy conversion is the only potential means for producing electrical energy from a fission reactor without the Carnot efficiency limitations. This project was undertaken by Sandia National Laboratories, Los Alamos National Laboratories, The University of Florida, Texas A&M University and General Atomics to explore the possibilities of direct energy conversion. Other means of producing electrical energy from a fission reactor, without any moving parts, are also within the statement of proposed work. This report documents the efforts of General Atomics. Sandia National Laboratories, the lead laboratory, provides overall project reporting and documentation.

  9. An analysis of tritium and fissile fuel exchange in fusion-fission systems

    E-Print Network [OSTI]

    Rice, Brent Lee

    1987-01-01T23:59:59.000Z

    power increases with time. The subscript 1 and 2 utilized in Fig. 1 refer to the fusile and fissile fuels, respectively. The subscripts H, F, and T refer to the fusion reactor, the fission power Fissile Trrtium (1-a) (CH CR1) RH Frssion Power... and fission power reactors, respectively, are: 13 d NT2 (C 1 ) R + a (C C 1 ) R dt (7) d NF2 (C -1) R + (1-a) (C -C ) R dt where N denotes the fuel inventory of a particular system component. C&1 and CT1 denote the number of tritium atoms produced...

  10. Interplay between compound and fragments aspects of nuclear fission and heavy-ion reaction

    SciTech Connect (OSTI)

    Moller, Peter [Los Alamos National Laboratory; Iwamoto, A [JAPAN; Ichikawa, I [JAPAN

    2010-09-10T23:59:59.000Z

    The scission point in nuclear fission plays a special role where one-body system changes to two-body system. Inverse of this situation is realized in heavy-ion fusion reaction where two-body system changes to one body system. Among several peculiar phenomena expected to occur during this change, we focus our attention to the behavior of compound and fragments shell effects. Some aspects of the interplay between compound and fragments shell effect are discussed related to the topics of the fission valleys in the potential energy surface of actinide nuclei and the fusion-like trajectory found in the cold fusion reaction leading to superheavy nuclei.

  11. The effect of. beta. -delayed fission on the production of r-process chronometers

    SciTech Connect (OSTI)

    Howard, W.M.; Meyer, B.S.

    1989-08-30T23:59:59.000Z

    The nuclear physics required for calculating the production ratios for the chronometric pairs {sup 235}U/{sup 232}Th and {sup 238}U/{sup 232}Th in the astrophysical r-process is considered in some detail. In particular, we calculate the nuclear structure of neutron-rich heavy elements to investigate the effects of beta-delayed fission and beta-delayed neutron emission during the beta decay from the r-process path to the actinide region. We find that previous estimates of the effects of beta-delayed fission on the production of these pairs has probably been overestimated. 11 refs., 1 fig.

  12. Proposal for ENDF formats that describe emission of post-fission beta-delayed photons

    SciTech Connect (OSTI)

    Brown, D; Pruet, J; Hedstrom, G; Hall, J; Descalle, M

    2004-09-15T23:59:59.000Z

    Fission of heavy nuclides is accompanied by the birth of neutron rich fragment nuclei born in highly excited states. Following emission of prompt neutrons and {gamma}-rays, these fragments are typically left with atomic numbers that are 3-4 units smaller than stable nuclei with the same mass number. As these nuclides undergo {beta} decay to reach stability, a large number of {gamma}-rays are emitted. Figure 1 illustrates some of the processes leading to emission of {beta} delayed photons. A variety of applications (most notably those concerned with the detection and identification of clandestine fissile material) would benefit from a clear description of the spectral and temporal evolution of these {gamma}-rays. This proposal describes formats for representing emission of delayed photons and is based on the analysis presented in. At the present time, no single evaluated data set exists that directly provides for the temporal evolution of {gamma} rays from the decay of the fission products. However, evaluated data sets containing all of the physical parameters required for such calculations have been prepared. These include estimates of the independent and cumulative fission yields of all fission products, branching ratios in the decay of ground and isomeric states, lifetimes of these states, and the spectra of {gamma} rays emitted in their decay. Sizeable uncertainties and possibly significant errors are likely present concerning the shortest-lived fission products. However, the high-energy {gamma}-ray spectra generated from some of these data sets have been shown to be in reasonable agreement with initial experiments designed specifically to test them under conditions likely to be of interest to interrogation of sea-going cargo containers. For clarity we emphasize that the relationship between delayed neutron emission and delayed photon emission is tenuous. Only a small fraction of fission fragments - typically those characterized by large decay Q values - undergo {beta}{sup -}n emission. However, essentially all fission fragment decays result in the emission of a few photons. Also, it would be impractical to accurately specify and measure energies of delayed neutrons. By contrast, most fission fragments have decay spectra known to sub-keV accuracy that are readily resolved with inexpensive field HpGe detectors.

  13. Overview of experimental support for fission-product transport analyses at Oak Ridge National Laboratory

    SciTech Connect (OSTI)

    Wichner, R.P.

    1983-01-01T23:59:59.000Z

    The program was designed to determine fission product and aerosol release rates from irradiated fuel under accident conditions, to identify the chemical forms of the released material, and to correlate the results with experimental and specimen conditions with the data from related experiments. These tests of PWR fuel were conducted and fuel specimen and test operating data are presented. The nature and rate of fission product vapor interaction with aerosols were studied. Aerosol deposition rates and transport in the reactor vessel during LWR core-melt accidents were studied. The Nuclear Safety Pilot Plant is dedicated to developing an expanded data base on the behavior of aerosols generated during a severe accident.

  14. From ground state to fission fragments: A complex, multi-dimensional multi-path problem

    SciTech Connect (OSTI)

    Moeller, P. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Nix, J.R. (Los Alamos National Lab., NM (United States)); Swiatecki, W.J. (Lawrence Berkeley Lab., CA (United States))

    1992-01-01T23:59:59.000Z

    Experimental results on the fission properties of nuclei close to {sup 264}Fm show sudden and large changes with a change of only one or two neutrons or protons. The nucleus {sup 258}Fm, for instance, undergoes symmetric fission with a half-life of about 0.4 ms and a kinetic-energy distribution peaked at about 235 MeV whereas {sup 256}Fm undergoes asymmetric fission with a half-life of about 3 h and a kinetic-energy distribution peaked at about 200 MeV. Qualitatively, these sudden changes have been postulated to be due to the emergence of fragment shells in symmetric-fission products close to {sup 132}Sn. Here we present a quantitative calculation that shows where high-kinetic-energy symmetric fusion occurs and why it is associated with a sudden and large decrease in fission half-lives. We base our study on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. We use the three-quadratic-surface parameterization to generate the shapes for which the potential-energy surfaces are calculated. The use of this parameterization and the use of the finite-range macroscopic model allows for the study of two touching spheres and similar shapes. Since these shapes are thought to correspond to the scission shapes for the high-kinetic-energy events it is of crucial importance that a continuous sequence of shapes leading from the nuclear ground state to these configurations can be studied within the framework of the model. We present the results of the calculations in terms of potential-energy surfaces and fission half-lives for heavy even nuclei. The surfaces are displayed in the form of contour diagrams as functions of two moments of the shape. They clearly show the appearance of a second fission valley, which leads to scission configurations close to tow touching spheres, for fissioning systems in the vicinity of {sup 264}Fm.

  15. From ground state to fission fragments: A complex, multi-dimensional multi-path problem

    SciTech Connect (OSTI)

    Moeller, P. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Nix, J.R. [Los Alamos National Lab., NM (United States); Swiatecki, W.J. [Lawrence Berkeley Lab., CA (United States)

    1992-03-01T23:59:59.000Z

    Experimental results on the fission properties of nuclei close to {sup 264}Fm show sudden and large changes with a change of only one or two neutrons or protons. The nucleus {sup 258}Fm, for instance, undergoes symmetric fission with a half-life of about 0.4 ms and a kinetic-energy distribution peaked at about 235 MeV whereas {sup 256}Fm undergoes asymmetric fission with a half-life of about 3 h and a kinetic-energy distribution peaked at about 200 MeV. Qualitatively, these sudden changes have been postulated to be due to the emergence of fragment shells in symmetric-fission products close to {sup 132}Sn. Here we present a quantitative calculation that shows where high-kinetic-energy symmetric fusion occurs and why it is associated with a sudden and large decrease in fission half-lives. We base our study on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. We use the three-quadratic-surface parameterization to generate the shapes for which the potential-energy surfaces are calculated. The use of this parameterization and the use of the finite-range macroscopic model allows for the study of two touching spheres and similar shapes. Since these shapes are thought to correspond to the scission shapes for the high-kinetic-energy events it is of crucial importance that a continuous sequence of shapes leading from the nuclear ground state to these configurations can be studied within the framework of the model. We present the results of the calculations in terms of potential-energy surfaces and fission half-lives for heavy even nuclei. The surfaces are displayed in the form of contour diagrams as functions of two moments of the shape. They clearly show the appearance of a second fission valley, which leads to scission configurations close to tow touching spheres, for fissioning systems in the vicinity of {sup 264}Fm.

  16. Thorium oxide slurries as blankets in fissile producing fusion- fission hybrids

    E-Print Network [OSTI]

    Geer, Thomas Charles

    1982-01-01T23:59:59.000Z

    of Advisory Committee: Dr. T. A. Parish An alternative to fixed-fertile and molten salt fissile producing fusion-fission hybrid blankets was developed. The neutronic feasibility of a thorium oxide-heavy water slurry as a blanket was tested for a Catalyzed... of continuous fission product and fissile material removal, thus limiting the in-situ burnup of the product. A natural consideration for such a fluid fuel system is a molten salt. Fluorides of either uranium of thorium can be dissilved in molten flouride...

  17. Experimental Determination of the Antineutrino Spectrum of the Fission Products of $^{238}$U

    E-Print Network [OSTI]

    N. Haag; A. Gütlein; M. Hofmann; L. Oberauer; W. Potzel; K. Schreckenbach; F. M. Wagner

    2013-12-19T23:59:59.000Z

    An experiment was performed at the scientific neutron source FRM II in Garching to determine the cumulative antineutrino spectrum of the fission products of $^{238}$U. This was achieved by irradiating target foils of natural uranium with a thermal and a fast neutron beam and recording the emitted $\\beta$-spectra with a gamma-suppressing electron-telescope. The obtained $\\beta$-spectrum of the fission products of $^{235}$U was normalized to the data of the magnetic spectrometer BILL of $^{235}$U. This method strongly reduces systematic errors in the $^{238}$U measurement. The $\\beta$-spectrum of $^{238}$U was converted into the corresponding antineutrino spectrum. The final $\\bar\

  18. Active-Interrogation Measurements of Fast Neutrons from Induced Fission in Low-Enriched Uranium

    SciTech Connect (OSTI)

    J. L. Dolan; M. J. Marcath; M. Flaska; S. A. Pozzi; D. L. Chichester; A. Tomanin; P. Peerani

    2014-02-01T23:59:59.000Z

    A detection system was designed with MCNPX-PoliMi to measure induced-fission neutrons from U-235 and U-238 using active interrogation. Measurements were then performed with this system at the Joint Research Centre (JRC) in Ispra, Italy on low-enriched uranium samples. Liquid scintillators measured induced fission neutron to characterize the samples in terms of their uranium mass and enrichment. Results are presented to investigate and support the use of organic liquid scintillators with active interrogation techniques to characterize uranium containing materials.

  19. Target and method for the production of fission product molybdenum-99

    DOE Patents [OSTI]

    Vandegrift, George F. (Bolingbrook, IL); Vissers, Donald R. (Naperville, IL); Marshall, Simon L. (Woodridge, IL); Varma, Ravi (Hinsdale, IL)

    1989-01-01T23:59:59.000Z

    A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm.sup.2 of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99.

  20. Spin Rotation of Formalism for Spin Tracking

    SciTech Connect (OSTI)

    Luccio,A.

    2008-02-01T23:59:59.000Z

    The problem of which coefficients are adequate to correctly represent the spin rotation in vector spin tracking for polarized proton and deuteron beams in synchrotrons is here re-examined in the light of recent discussions. The main aim of this note is to show where some previous erroneous results originated and how to code spin rotation in a tracking code. Some analysis of a recent experiment is presented that confirm the correctness of the assumptions.

  1. Influence of complete energy sorting on the characteristics of the odd-even effect in fission-fragment element distributions

    E-Print Network [OSTI]

    Beatriz Jurado; Karl-Heinz Schmidt

    2014-11-17T23:59:59.000Z

    The characteristics of the odd-even effect in fission-fragment Z distributions are compared to a model based on statistical mechanics. Special care is taken for using a consistent description for the influence of pairing correlations on the nuclear level density. The variation of the odd-even effect with the mass of the fissioning nucleus and with fission asymmetry is explained by the important statistical weight of configurations where the light nascent fission fragment populates the lowest energy state of an even-even nucleus. This implies that entropy drives excitation energy and unpaired nucleons predominantly to the heavy fragment. Therefore, within our model, the odd-even effect appears as an additional signature of the recently discovered energy-sorting process in nuclear fission.

  2. Location-Tracking Applications ecent technological advances in wireless loca-

    E-Print Network [OSTI]

    Gruteser, Marco

    areas they have visited. #12;Location-Tracking Applications broker as part of their service contract

  3. Original Article Clinician-Educator Tracks for Residents

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    , and graduate outcomes. Results: Common elements in the tracks are faculty mentor- ship, formal didactics

  4. Multi-camera detection, tracking and re-identification

    E-Print Network [OSTI]

    Cavallaro, Andrea

    domotics Building service optimisat. security Facility goods tracking safety City traffic control planning

  5. ENVIRONMENTAL STUDIES TRACK (B.S.) 2013-2014 CATALOG

    E-Print Network [OSTI]

    Wu, Shin-Tson

    June 2012 ENVIRONMENTAL STUDIES TRACK (B.S.) 2013-2014 CATALOG There are three tracks in Interdisciplinary Studies (IS). This handout is for the Environmental Studies track. Office Classroom I ­ Suite 302 for students seeking a combination of studies. The Environmental Studies track is designed for students who

  6. track 4: enhanced geothermal systems (EGS) | geothermal 2015...

    Energy Savers [EERE]

    rack4EGS1.7RaftRiver.pdf Track4EGS1.8EGSStimulationPlummer.pdf Track4EGS1.9SeismicImaging.pdf Track4EGS2.1PettynewberryEGS2015.pdf Track4EGS2.2SonnenthalNewbe...

  7. Characterization of tracked radiofrequency ablation in phantom

    SciTech Connect (OSTI)

    Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L. [Department of Biomedical Engineering, Vanderbilt University, 5824 Stevenson Center, Nashville, Tennessee 37235 (United States)

    2007-10-15T23:59:59.000Z

    In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4{+-}0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA.

  8. Assessment of a mechanistic model in U-Pu-Zr metallic alloy fuel fission-gas behavior simulations

    SciTech Connect (OSTI)

    Yun, D.; Rest, J.; Yacout, A. M. [Argonne National Laboratory, 9700 S. Cass Ave., Argonne, IL 60439 (United States)

    2012-07-01T23:59:59.000Z

    A mechanistic kinetic rate theory model originally developed for the prediction of fission gas behavior in oxide nuclear fuels under steady-state and transient conditions has been assessed to look at its applicability to model fission gas behavior in U-Pu-Zr metallic alloy fuel. In order to capture and validate the underlying physics for irradiated U-Pu-Zr fuels, the mechanistic model was applied to the simulation of fission gas release, fission gas and fission product induced swelling, and the evolution of the gas bubble size distribution in three different fuel zones: the outer {alpha}-U, the intermediate, and the inner {gamma}-U zones. Due to its special microstructural features, the {alpha}-U zone in U-Pu-Zr fuels is believed to contribute the largest fraction of fission gas release among the different fuel zones. It is shown that with the use of small effective grain sizes, the mechanistic model can predict fission gas release that is consistent with (though slightly lower than) experimentally measured data. These simulation results are comparable to the experimentally measured fission gas release since the mechanism of fission gas transport through the densely distributed laminar porosity in the {alpha}-U zone is analogous to the mechanism of fission gas transport through the interconnected gas bubble porosity utilized in the mechanistic model. Detailed gas bubble size distributions predicted with the mechanistic model in both the intermediate zone and the high temperature {gamma}-U zone of U-Pu-Zr fuel are also compared to experimental measurements from available SEM micrographs. These comparisons show good agreements between the simulation results and experimental measurements, and therefore provide crucial guidelines for the selection of key physical parameters required for modeling these two zones. In addition, the results of parametric studies for several key parameters are presented for both the intermediate zone and the {gamma}-U zone simulations. (authors)

  9. Interference of fission amplitudes of neutron resonances and T-odd asymmetry for various prescission third particles in the ternary fission of nuclei

    SciTech Connect (OSTI)

    Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru [Voronezh State University (Russian Federation); Bunakov, V. E. [Russian Academy of Sciences, Petersburg Nuclear Physics Institute (Russian Federation); Kadmensky, S. S. [Voronezh State University (Russian Federation)

    2011-12-15T23:59:59.000Z

    Differential cross sections for reactions of the true ternary fission of nuclei that was induced by cold polarized neutrons were constructed with allowance of the effect that Coriolis interaction and the interference between fission amplitudes of neutron resonances excited in fissile nuclei upon incidentneutron capture by target nuclei exerted on angular distributions of prescission third particles (alpha particles, neutrons, or photons). It is shown that T -odd TRI- and ROT-type asymmetries for prescission alpha particles are associated with, respectively, the odd and even components of the Coriolis interaction-perturbed amplitude of angular distributions of particles belonging to the types indicated above. These asymmetries have angular distributions differing from each other and stemming from a nontrivial dependence of these components on the neutron-resonance spins J{sub s} and their projections K{sub s} onto the symmetry axis of the nucleus involved. It is shown that angular distributions of prescission photons and neutrons from reactions of the ternary fission of nuclei that is induced by cold polarized neutrons are determined by the effect of Coriolis forces exclusively. Therefore, the emerging T-odd asymmetries have a character of a ROT-type asymmetry and are universal for all target nuclei.

  10. Nuclear spin-orbit interaction and T-odd angular correlations in ternary fission

    E-Print Network [OSTI]

    Barabanov, A L

    2014-01-01T23:59:59.000Z

    T-odd angular correlations in ternary fission of 233-U and 235-U nuclei by slow polarized neutrons are not related to TRI (time reversal invariance) violation, but are caused by an effective spin-orbit interaction in the final state.

  11. Monte Carlo Hauser-Feshbach Modeling of Prompt Fission Neutrons and Gamma Rays

    E-Print Network [OSTI]

    Danon, Yaron

    calculations taking into account the competition between the emissions of prompt fission neutrons and gamma constitute the first signature of post-scission physics. They indicate not only how much total energy description of the neutron-gamma competition, albeit in a phenomenological correction to the Weisskopf

  12. On the origin of high- spin states in nuclear fission fragments

    E-Print Network [OSTI]

    G. Mouze; C. Ythier; S. Hachem

    2011-03-28T23:59:59.000Z

    In the "nucleon-phase" model of binary fission, the transfer of nucleons between an A =126 {\\guillemotleft} nucleon core {\\guillemotright} and the primordial "cluster" can explain both the formation of high- spin states and the saw-tooth behavior of the variation, as a function of fragment mass, of the average angular momentum.

  13. Nuclear spin-orbit interaction and T-odd angular correlations in ternary fission

    E-Print Network [OSTI]

    A. L. Barabanov

    2014-07-08T23:59:59.000Z

    T-odd angular correlations in ternary fission of 233-U and 235-U nuclei by slow polarized neutrons are not related to TRI (time reversal invariance) violation, but are caused by an effective spin-orbit interaction in the final state.

  14. VII. Nuclear Chemistry (Chapter 17) A. Modes of radioactive decay, nuclear reactions, fission, fusion

    E-Print Network [OSTI]

    40 VII. Nuclear Chemistry (Chapter 17) A. Modes of radioactive decay, nuclear reactions, fission #12;41 These masses are not exactly integer multiples due to nuclear interactions between the protons differences via the famous formula E = mc2 . Nuclear Fusion! For example, if you combine 2 protons and two

  15. PHYSICAL REVIEW C 87, 014617 (2013) Monte Carlo Hauser-Feshbach predictions of prompt fission rays

    E-Print Network [OSTI]

    Danon, Yaron

    Nuclear Theory Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA (Received 14 for the evaporation of the excited fission fragments. Remaining free model parameters, such as excitation energy, multiplicity distribution, average multiplicity and energy, and multiplicity distribution, are calculated

  16. RIS-M-2472 FORCED DECONTAMINATION OF FISSION PRODUCTS DEPOSITED ON

    E-Print Network [OSTI]

    a serious reactor accident. Areas of special concern are cities where the collective dose might be high, DECONTAMINATION, FISSION, PROD- UCTS, REACTOR ACCIDENTS, REMEDIAL ACTION, REVIEWS, ROADS, SURFACE CLEANING-550-1067-9 ISSN 0418-6435 Risø Repro 1985 #12;CONTENTS Paqe 1. INTRODUCTION 5 2. DECONTAMINATION PRINCIPLES 6 2

  17. Key to images: [1] Model system: fission yeast [2] Cryo-EM structure

    E-Print Network [OSTI]

    Brierley, Andrew

    Key to images: [1] Model system: fission yeast [2] Cryo-EM structure of the MCM helicase [3 combing [8] Model system: Xenopus [9] Extreme environments [10] Model system: C.elegans. Background image of the evolution of the replication machinery highlighted. BSRC B306 Email: sam31@st-and.ac.uk 1 2 3 4 5 6 7 8 9 10

  18. Fission signal detection using helium-4 gas fast neutron scintillation detectors

    SciTech Connect (OSTI)

    Lewis, J. M., E-mail: lewisj@ufl.edu; Kelley, R. P.; Jordan, K. A. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611 (United States); Murer, D. [Arktis Radiation Detectors Ltd., 8045 Zurich (Switzerland)

    2014-07-07T23:59:59.000Z

    We demonstrate the unambiguous detection of the fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium fusion neutron generator and a high pressure {sup 4}He gas fast neutron scintillation detector. The energy deposition by individual neutrons is quantified, and energy discrimination is used to differentiate the induced fission neutrons from the mono-energetic interrogation neutrons. The detector can discriminate between different incident neutron energies using pulse height discrimination of the slow scintillation component of the elastic scattering interaction between a neutron and the {sup 4}He atom. Energy histograms resulting from this data show the buildup of a detected fission neutron signal at higher energies. The detector is shown here to detect a unique fission neutron signal from a natural uranium sample during active interrogation with a (d, d) neutron generator. This signal path has a direct application to the detection of shielded nuclear material in cargo and air containers. It allows for continuous interrogation and detection while greatly minimizing the potential for false alarms.

  19. Detection of uranium-based nuclear weapons using neutron-induced fission

    SciTech Connect (OSTI)

    Moss, C.E.; Byrd, R.C.; Feldman, W.C.; Auchampaugh, G.F.; Estes, G.P. [Los Alamos National Lab., NM (United States); Ewing, R.I.; Marlow, K.W. [Sandia National Labs., Albuquerque, NM (United States)

    1991-12-01T23:59:59.000Z

    Although plutonium-based nuclear weapons can usually be detected by their spontaneous emission of neutrons and gammas, the radiation emitted by weapons based entirely on highly-enriched uranium can often be easily shielded. Verification of a treaty that limits the number of such weapons may require an active technique, such as interrogating the suspect assembly with an external neutron source and measuring the number of fission neutrons produced. Difficulties include distinguishing between source and fission neutrons, the variations in yield for different materials and geometries, and the possibility of non-nuclear weapons that may contain significant amounts of fissionable depleted uranium. We describe simple measurements that test the induced-fission technique using an isotopic Am-Li source, an novel energy-sensitive neutron detector, and several small assemblies containing {sup 235}U, {sup 238}U, lead, and polyethylene. In all cases studied, the neutron yields above the source energy are larger for the {sup 235}U assemblies than for assemblies containing only lead or depleted uranium. For more complex geometries, corrections for source transmission may be necessary. The results are promising enough to recommend further experiments and calculations using examples of realistic nuclear and non-nuclear weapons. 5 refs., 11 figs.

  20. Detection of uranium-based nuclear weapons using neutron-induced fission

    SciTech Connect (OSTI)

    Moss, C.E.; Byrd, R.C.; Feldman, W.C.; Auchampaugh, G.F.; Estes, G.P. (Los Alamos National Lab., NM (United States)); Ewing, R.I.; Marlow, K.W. (Sandia National Labs., Albuquerque, NM (United States))

    1991-01-01T23:59:59.000Z

    Although plutonium-based nuclear weapons can usually be detected by their spontaneous emission of neutrons and gammas, the radiation emitted by weapons based entirely on highly-enriched uranium can often be easily shielded. Verification of a treaty that limits the number of such weapons may require an active technique, such as interrogating the suspect assembly with an external neutron source and measuring the number of fission neutrons produced. Difficulties include distinguishing between source and fission neutrons, the variations in yield for different materials and geometries, and the possibility of non-nuclear weapons that may contain significant amounts of fissionable depleted uranium. We describe simple measurements that test the induced-fission technique using an isotopic Am-Li source, an novel energy-sensitive neutron detector, and several small assemblies containing {sup 235}U, {sup 238}U, lead, and polyethylene. In all cases studied, the neutron yields above the source energy are larger for the {sup 235}U assemblies than for assemblies containing only lead or depleted uranium. For more complex geometries, corrections for source transmission may be necessary. The results are promising enough to recommend further experiments and calculations using examples of realistic nuclear and non-nuclear weapons. 5 refs., 11 figs.

  1. Comparison of neutron diffusion and Monte Carlo simulations of a fission wave

    E-Print Network [OSTI]

    Deinert, Mark

    common con- figuration a fertile material, such as depleted uranium, is subjected to a fast neutron flux). The fresh fuel zone consisted of depleted uranium groups have shown that fission waves could form in uranium and potentially be used as the basis

  2. innovati nSinglet Fission Holds Two-for-One Potential in Solar Cells

    E-Print Network [OSTI]

    of light. · This energy excites the electrons from their low-energy ground state (S0) to an excited high-energy, including 10% post consumer waste. The bottom line is that one high-energy photon can produce two electron energy in excess of the bandgap energy is lost as wasted heat. In contrast, singlet fission produces the

  3. Tracking Graphics State forTracking Graphics State for Network RenderingNetwork Rendering

    E-Print Network [OSTI]

    Pratt, Vaughan

    Tracking Graphics State forTracking Graphics State for Network RenderingNetwork Rendering Ian Buck 2000 Distributed GraphicsDistributed Graphics Application Application Application Renderer Renderer Renderer Network How to manage distributed graphics applications, renderers, and displays? #12;HWWS 2000

  4. CDC's National Environmental Public Health Tracking Network MAINE Keeping Track, Promoting Health

    E-Print Network [OSTI]

    analysis systems. These systems provide health planners, policymakers, and other decision makers critical risk factors. For example, the new analysis revealed that 40% of all childhood lead poisonings (Tracking Network). The Tracking Network is a dynamic Web-based tool that, for the first time, provides

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

    SciTech Connect (OSTI)

    Blaise Collin

    2014-09-01T23:59:59.000Z

    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.

  6. Kalman Filter Tracking on Parallel Architectures

    E-Print Network [OSTI]

    Cerati, Giuseppe; Lantz, Steven; McDermott, Kevin; Riley, Dan; Tadel, Matevž; Wittich, Peter; Würthwein, Frank; Yagil, Avi

    2015-01-01T23:59:59.000Z

    Power density constraints are limiting the performance improvements of modern CPUs. To address this we have seen the introduction of lower-power, multi-core processors, but the future will be even more exciting. In order to stay within the power density limits but still obtain Moore's Law performance/price gains, it will be necessary to parallelize algorithms to exploit larger numbers of lightweight cores and specialized functions like large vector units. Example technologies today include Intel's Xeon Phi and GPGPUs. Track finding and fitting is one of the most computationally challenging problems for event reconstruction in particle physics. At the High Luminosity LHC, for example, this will be by far the dominant problem. The need for greater parallelism has driven investigations of very different track finding techniques including Cellular Automata or returning to Hough Transform. The most common track finding techniques in use today are however those based on the Kalman Filter. Significant experience has...

  7. Automatically processed alpha-track radon monitor

    DOE Patents [OSTI]

    Langner, G.H. Jr.

    1993-01-12T23:59:59.000Z

    An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

  8. Detecting special nuclear materials in suspect containers using high-energy gamma rays emitted by fission products

    DOE Patents [OSTI]

    Norman, Eric B. (Oakland, CA); Prussin, Stanley G. (Kensington, CA)

    2009-01-06T23:59:59.000Z

    A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  9. Detecting special nuclear materials in suspect containers using high-energy gamma rays emitted by fission products

    DOE Patents [OSTI]

    Norman, Eric B. (Oakland, CA); Prussin, Stanley G. (Kensington, CA)

    2009-01-27T23:59:59.000Z

    A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  10. Detecting special nuclear materials in suspect containers using high-energy gamma rays emitted by fission products

    DOE Patents [OSTI]

    Norman, Eric B [Oakland, CA; Prussin, Stanley G [Kensington, CA

    2009-05-05T23:59:59.000Z

    A method and a system for detecting the presence of special nuclear materials in a suspect container. The system and its method include irradiating the suspect container with a beam of neutrons, so as to induce a thermal fission in a portion of the special nuclear materials, detecting the gamma rays that are emitted from the fission products formed by the thermal fission, to produce a detector signal, comparing the detector signal with a threshold value to form a comparison, and detecting the presence of the special nuclear materials using the comparison.

  11. Tracking Provenance in ORNL's Flexible Research Platforms

    SciTech Connect (OSTI)

    Hensley, Zachary P [ORNL; Sanyal, Jibonananda [ORNL; New, Joshua Ryan [ORNL

    2013-08-01T23:59:59.000Z

    Provenance is dened as information about the origin of objects, a concept that applies to both physical and digital objects and often overlaps both. The use of provenance in systems designed for research is an important but forgotten feature. Provenance allows for proper and exact tracking of information, its use, its lineage, its derivations and other metadata that are important for correctly adhering to the scien- tic method. In our project's prescribed use of provenance, researchers can determine detailed information about the use of sensor data in their experiments on ORNL's Flexible Research Platforms (FRPs). Our project's provenance system, Provenance Data Management System (ProvDMS), tracks information starting with the creation of information by an FRP sensor. The system determines station information, sensor information, and sensor channel information. The system allows researchers to derive generations of experiments from the sensor data and tracks their hierarchical flow. Key points can be seen in the history of the information as part of the information's workflow. The concept of provenance and its usage in science is relatively new and while used in other cases around the world, our project's provenance diers in a key area. To keep track of provenance, most systems must be designed or redesigned around the new provenance system. Our system is designed as a cohesive but sepa- rate entity and allows for researchers to continue using their own methods of analysis without being constrained in their ways in order to track the provenance. We have designed ProvDMS using a lightweight provenance library, Core Provenance Library (CPL) v.6 In addition to keeping track of sensor data experiments and its provenance, ProvDMS also provides a web-enabled visualization of the inheritance.

  12. Chemical tracking at the Rocky Flats Plant

    SciTech Connect (OSTI)

    Costain, D.B.

    1994-04-01T23:59:59.000Z

    EG&G Rocky Flats, Inc., has developed a chemical tracking system to support compliance with the Emergency Planning and community Right-to-Know Act (EPCRA) at the Rocky Flats Plant. This system, referred to as the EPCRA Chemical Control system (ECCS), uses bar code technology to uniquely identify and track the receipt, distribution, and use of chemicals. Chemical inventories are conducted using hand-held electronic scanners to update a site wide chemical database on a VAX 6000 computer. Information from the ECCS supports preparation of the EPCRA Tier II and Form R reports on chemical storage and use.

  13. Evidence of Southern Health

    E-Print Network [OSTI]

    Acton, Scott

    POS Evidence of Coverage Southern Health Services, Inc. SH.POS.11-09 #12;Table of Contents SH................................................................................................10 Facts about Southern Health .....................................................................12 Members' Responsibilities to Know How and When to Seek Care ............................13 Section

  14. Method of assaying uranium with prompt fission and thermal neutron borehole logging adjusted by borehole physical characteristics. [Patient application

    DOE Patents [OSTI]

    Barnard, R.W.; Jensen, D.H.

    1980-11-05T23:59:59.000Z

    Uranium formations are assayed by prompt fission neutron logging techniques. The uranium in the formation is proportional to the ratio of epithermal counts to thermal or epithermal dieaway. Various calibration factors enhance the accuracy of the measurement.

  15. Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS

    SciTech Connect (OSTI)

    Perkasa, Y. S. [Department of Physics, Sunan Gunung Djati State Islamic University Bandung, Jl. A.H Nasution No. 105 Cibiru, Bandung (Indonesia); Waris, A., E-mail: awaris@fi.itb.ac.id; Kurniadi, R., E-mail: awaris@fi.itb.ac.id; Su'ud, Z., E-mail: awaris@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesa No. 10 Bandung 40132 (Indonesia)

    2014-09-30T23:59:59.000Z

    Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS have been conducted. In this work, fission cross section resulted from MCNP6 prediction will be compared with result from TALYS calculation. MCNP6 with its event generator CEM03.03 and LAQGSM03.03 have been validated and verified for several intermediate and heavy nuclides fission reaction data and also has a good agreement with experimental data for fission reaction that induced by photons, pions, and nucleons at energy from several ten of MeV to about 1 TeV. The calculation that induced within TALYS will be focused mainly to several hundred MeV for actinide and sub-actinide nuclides and will be compared with MCNP6 code and several experimental data from other evaluator.

  16. Role of ex-vessel interactions in determining the severe reactor-accident source term for fission products. [PWR; BWR

    SciTech Connect (OSTI)

    Powers, D.A.; Brockmann, J.E.; Bradley, D.R.; Tarbell, W.W.

    1983-01-01T23:59:59.000Z

    The role fission-product release and aerosol generation outside the primary system can have in determining the severe reactor-accident source term is reviewed. Recent analytical and experimental studies of major causes of ex-vessel fission product release and aerosol generation are described. The ejection of molten-core debris from a pressurized-reactor vessel is shown to be a potentially large source of aerosols that has not been recognized in past severe-accident evaluations. A mechanistic model of fission-product release during core-debris interactions with concrete is discussed. Calculations with this model are compared to correlations of experimental data and previous estimates of ex-vessel fission-product release. Predictions with the mechanistic model agree quite well with the data correlations but do not agree at all well with estimates made in the past.

  17. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    1.1.3.2 Fusion Energy . . . . . . . . . 1.1.3.3 Fission-Laser Inertial Fusion-based Energy 2.1 Potentialaspects of magnetic fusion energy, September 1989. 1.1.3.2 [

  18. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    4.3.3.4 Chamber Radius and Fusion Neutron Flux . . . . .1.1.3.2 Fusion Energy . . . . . . . . .1.1.3.3 Fission-Fusion Hybrids . . . . 1.2 Scope and Purpose

  19. Realistic fission models, new beta-decay half-lives and the r-process in neutron star mergers

    SciTech Connect (OSTI)

    Shibagaki, S.; Kajino, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8850 (Japan); Lorusso, G.; Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556 (United States)

    2014-05-02T23:59:59.000Z

    Almost half of heavy nuclei beyond iron are considered to be produced by rapid neutron capture process (r-process). This process occurs in the neutron-rich environment such as core-collapse supernovae or neutron star mergers, but the main production site is still unknown. In the r-process of neutron star mergers, nuclear fission reactions play an important role. Also beta-decay half-lives of magic nuclei are crucial for the r-process. We have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions and new beta-decay half-lives for N=82 nuclei measured at RIBF-RIKEN. We investigate the effect of nuclear fission on abundance patterns in the matter ejected from neutron star mergers with two different fission fragment mass distributions. We also discuss how the new experimental beta-decay half-lives affect the r-process.

  20. Laser Inertial Fusion-based Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    E-Print Network [OSTI]

    Kramer, Kevin James

    2010-01-01T23:59:59.000Z

    DT Deuterium-Tritium DU Depleted Uranium FIMA Fission ofengine loaded with depleted uranium. In Proc. PHYSOR 2010,in the form of depleted uranium (DU). The remaining ~3,075