Science.gov

Sample records for advanced fission energy

  1. Advanced Space Fission Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Borowski, Stanley K.

    2010-01-01

    Fission has been considered for in-space propulsion since the 1940s. Nuclear Thermal Propulsion (NTP) systems underwent extensive development from 1955-1973, completing 20 full power ground tests and achieving specific impulses nearly twice that of the best chemical propulsion systems. Space fission power systems (which may eventually enable Nuclear Electric Propulsion) have been flown in space by both the United States and the Former Soviet Union. Fission is the most developed and understood of the nuclear propulsion options (e.g. fission, fusion, antimatter, etc.), and fission has enjoyed tremendous terrestrial success for nearly 7 decades. Current space nuclear research and technology efforts are focused on devising and developing first generation systems that are safe, reliable and affordable. For propulsion, the focus is on nuclear thermal rockets that build on technologies and systems developed and tested under the Rover/NERVA and related programs from the Apollo era. NTP Affordability is achieved through use of previously developed fuels and materials, modern analytical techniques and test strategies, and development of a small engine for ground and flight technology demonstration. Initial NTP systems will be capable of achieving an Isp of 900 s at a relatively high thrust-to-weight ratio. The development and use of first generation space fission power and propulsion systems will provide new, game changing capabilities for NASA. In addition, development and use of these systems will provide the foundation for developing extremely advanced power and propulsion systems capable of routinely and affordably accessing any point in the solar system. The energy density of fissile fuel (8 x 10(exp 13) Joules/kg) is more than adequate for enabling extensive exploration and utilization of the solar system. For space fission propulsion systems, the key is converting the virtually unlimited energy of fission into thrust at the desired specific impulse and thrust

  2. Advanced modeling of prompt fission neutrons

    SciTech Connect

    Talou, Patrick

    2009-01-01

    Theoretical and numerical studies of prompt fission neutrons are presented. The main results of the Los Alamos model often used in nuclear data evaluation work are reviewed briefly, and a preliminary assessment of uncertainties associated with the evaluated prompt fission neutron spectrum for n (0.5 MeV)+{sup 239}Pu is discussed. Advanced modeling of prompt fission neutrons is done by Monte Carlo simulations of the evaporation process of the excited primary fission fragments. The successive emissions of neutrons are followed in the statistical formalism framework, and detailed information, beyond average quantities, can be inferred. This approach is applied to the following reactions: {sup 252}Cf (sf), n{sub th} + {sup 239}Pu, n (0.5 MeV)+{sup 235}U, and {sup 236}Pu (sf). A discussion on the merits and present limitations of this approach concludes this presentation.

  3. PRODUCING ENERGY AND RADIOACTIVE FISSION PRODUCTS

    DOEpatents

    Segre, E.; Kennedy, J.W.; Seaborg, G.T.

    1959-10-13

    This patent broadly discloses the production of plutonium by the neutron bombardment of uranium to produce neptunium which decays to plutonium, and the fissionability of plutonium by neutrons, both fast and thermal, to produce energy and fission products.

  4. Fission Energy and Other Sources of Energy

    ERIC Educational Resources Information Center

    Alfven, Hannes

    1974-01-01

    Discusses different forms of energy sources and basic reasons for the opposition to the use of atomic energy. Suggests that research efforts should also be aimed toward the fission technology to make it acceptable besides major research studies conducted in the development of alternative energy sources. (CC)

  5. Fusion-fission energy systems evaluation

    SciTech Connect

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

    1980-01-01

    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.

  6. Advanced fission and fossil plant economics-implications for fusion

    SciTech Connect

    Delene, J.G.

    1994-09-01

    In order for fusion energy to be a viable option for electric power generation, it must either directly compete with future alternatives or serve as a reasonable backup if the alternatives become unacceptable. This paper discusses projected costs for the most likely competitors with fusion power for baseload electric capacity and what these costs imply for fusion economics. The competitors examined include advanced nuclear fission and advanced fossil-fired plants. The projected costs and their basis are discussed. The estimates for these technologies are compared with cost estimates for magnetic and inertial confinement fusion plants. The conclusion of the analysis is that fusion faces formidable economic competition. Although the cost level for fusion appears greater than that for fission or fossil, the costs are not so high as to preclude fusion`s potential competitiveness.

  7. Fission dynamics at low excitation energy

    NASA Astrophysics Data System (ADS)

    Aritomo, Y.; Chiba, S.; Ivanyuk, F.

    2014-11-01

    The mass asymmetry in the fission of 236U at low excitation energy is clarified by the analysis of the trajectories obtained by solving the Langevin equations for the shape degrees of freedom. It is demonstrated that the position of the peaks in the mass distribution of fission fragments is determined mainly by the saddle point configuration originating from the shell correction energy. The width of the peaks, on the other hand, results from the shape fluctuations close to the scission point caused by the random force in the Langevin equation. We have found out that the fluctuations between elongated and compact shapes are essential for the fission process. According to our results the fission does not occur with continuous stretching in the prolate direction, similarly to that observed in starch syrup, but is accompanied by the fluctuations between elongated and compact shapes. This picture presents a new viewpoint of fission dynamics and the splitting mechanism.

  8. Low energy fission: dynamics and scission configurations

    NASA Astrophysics Data System (ADS)

    Goutte, H.; Berger, J.-F.; Gogny, D.; Younes, W.

    2005-11-01

    In the first part of this paper we recall a recent study concerning low energy fission dynamics. Propagation is made by use of the Time Dependent Generator Coordinate Method, where the basis states are taken from self-consistent Hartree-Fock-Bogoliubov calculations with the Gogny force. Theoretical fragment mass distributions are presented and compared with the evaluation made by Wahl. In the second part of this paper, new results concerning scission configurations are shown. Deviations of the fission fragment proton numbers from the Unchanged Charge Distribution prescription and fission fragment deformations are discussed.

  9. Energy Correlation of Prompt Fission Neutrons

    NASA Astrophysics Data System (ADS)

    Elter, Zs.; Pázsit, I.

    2016-03-01

    In all cases where neutron fluctuations in a branching process (such as in multiplicity measurements) are treated in an energy dependent description, the energy correlations of the branching itself (energy correlations of the fission neutrons) need to be known. To date, these are not known from experiments. Such correlations can be theoretically and numerically derived by modelling the details of the fission process. It was suggested earlier that the fact that the prompt neutrons are emitted from the moving fission targets, will influence their energy and angular distributions in the lab system, which possibly induces correlations. In this paper the influence of the neutron emission process from the moving targets on the energy correlations is investigated analytically and via numerical simulations. It is shown that the correlations are generated by the random energy and direction distributions of the fission fragments. Analytical formulas are derived for the two-point energy distributions, and quantitative results are obtained by Monte-Carlo simulations. The results lend insight into the character of the two-point distributions, and give quantitative estimates of the energy correlations, which are generally small.

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

    SciTech Connect

    Ferguson, Robert L.

    1980-03-01

    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.

  11. A fission matrix based validation protocol for computed power distributions in the advanced test reactor

    SciTech Connect

    Nielsen, J. W.; Nigg, D. W.; LaPorta, A. W.

    2013-07-01

    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. Fission foil detector calibrations with high energy protons

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Frank, A. L.

    1995-01-01

    Fission foil detectors (FFD's) are passive devices composed of heavy metal foils in contact with muscovite mica films. The heavy metal nuclei have significant cross sections for fission when irradiated with neutrons and protons. Each isotope is characterized by threshold energies for the fission reactions and particular energy-dependent cross sections. In the FFD's, fission fragments produced by the reactions are emitted from the foils and create latent particle tracks in the adjacent mica films. When the films are processed surface tracks are formed which can be optically counted. The track densities are indications of the fluences and spectra of neutrons and/or protons. In the past, detection efficiencies have been calculated using the low energy neutron calibrated dosimeters and published fission cross sections for neutrons and protons. The problem is that the addition of a large kinetic energy to the (n,nucleus) or (p,nucleus) reaction could increase the energies and ranges of emitted fission fragments and increase the detector sensitivity as compared with lower energy neutron calibrations. High energy calibrations are the only method of resolving the uncertainties in detector efficiencies. At high energies, either proton or neutron calibrations are sufficient since the cross section data show that the proton and neutron fission cross sections are approximately equal. High energy proton beams have been utilized (1.8 and 4.9 GeV, 80 and 140 MeV) for measuring the tracks of fission fragments emitted backward and forward.

  13. Generalized Energy-Dependent Q Values for Fission

    SciTech Connect

    Vogt, R

    2010-03-31

    We extend Madland's parameterization of the energy release in fission to obtain the dependence of the fission Q value for major and minor actinides on the incident neutron energies in the range 0 {le} E{sub n} {le} 20 MeV. Our parameterization is based on the actinide evaluations recommended for the ENDF/B-VII.1 release. This paper describes the calculation of energydependent fission Q values based on the calculation of the prompt energy release in fission by Madland. This calculation was adopted for use in the LLNL ENDL database and then generalized to obtain the prompt fission energy release for all actinides. Here the calculation is further generalized to the total energy release in fission. There are several stages in a fission event, depending on the time scale. Neutrons and gammas may be emitted at any time during the fission event.While our discussion here is focussed on compound nucleus creation by an incident neutron, similar parameterizations could be obtained for incident gammas or spontaneous fission.

  14. Study on fission blanket fuel cycling of a fusion-fission hybrid energy generation system

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Yang, Y.; Xu, H.

    2011-10-01

    This paper presents a preliminary study on neutron physics characteristics of a light water cooled fission blanket for a new type subcritical fusion-fission hybrid reactor aiming at electric power generation with low technical limits of fission fuel. The major objective is to study the fission fuel cycling performance in the blanket, which may possess significant impacts on the feasibility of the new concept of fusion-fission hybrid reactor with a high energy gain (M) and tritium breeding ratio (TBR). The COUPLE2 code developed by the Institute of Nuclear and New Energy Technology of Tsinghua University is employed to simulate the neutronic behaviour in the blanket. COUPLE2 combines the particle transport code MCNPX with the fuel depletion code ORIGEN2. The code calculation results show that soft neutron spectrum can yield M > 20 while maintaining TBR >1.15 and the conversion ratio of fissile materials CR > 1 in a reasonably long refuelling cycle (>five years). The preliminary results also indicate that it is rather promising to design a high-performance light water cooled fission blanket of fusion-fission hybrid reactor for electric power generation by directly loading natural or depleted uranium if an ITER-scale tokamak fusion neutron source is achievable.

  15. Heavy-ion fission probability calculations at high excitation energy

    SciTech Connect

    D'Arrigo, A.; Giardina, G.; Taccone, A. Istituto Nazionale di Fisica Nucleare, Gruppo Collegato di Messina, Messina Istituto di Tecniche Spettroscopiche del Consiglio Nazionale delle Ricerche, Messina )

    1991-12-01

    In the framework of the statistical theory of nuclear reactions we calculated the fission probability {ital P}{sub {ital f}} of the {sup 153}Tb, {sup 158}Er, {sup 159}Dy, {sup 175}Hf, {sup 179}Ta, {sup 186}Os, and {sup 188}Os nuclei with a mass number {ital A}=150--200 produced by heavy-ion reactions. Starting from the spectra of the single-particle levels as determined by Nix and Moeller, and utilizing a formalism we developed, we determined the excitation energy dependence of the effective level density parameters for the fission and the neutron emission channels. The agreement between the fission probability calculations and the experimental data was reached when a nonadiabatic estimate of the collective effects was used to calculate the nuclear level density. In the fission process at high excitation energies induced by ions heavier than the {alpha} particle, an energy dependence of the effective fission barrier has to be used.

  16. The Future of Energy from Nuclear Fission

    SciTech Connect

    Kim, Son H.; Taiwo, Temitope

    2013-04-13

    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

  17. Energy-Dependent Fission Q Values Generalized for All Actinides

    SciTech Connect

    Vogt, R

    2008-09-25

    We generalize Madland's parameterization of the energy release in fission to obtain the dependence of the fission Q values on incident neutron energy, E{sub n}, for all major and minor actinides. These Q(E{sub n}) parameterizations are included in the ENDL2008 release. This paper describes calculations of energy-dependent fission Q values based on parameterizations of the prompt energy release in fission [1], developed by Madland [1] to describe the prompt energy release in neutron-induced fission of {sup 235}U, {sup 238}U, and {sup 239}Pu. The energy release is then related to the energy deposited during fission so that experimentally measurable quantities can be used to obtain the Q values. A discussion of these specific parameterizations and their implementation in the processing code for Monte Carlo neutron transport, MCFGEN, [2] is described in Ref. [3]. We extend this model to describe Q(E) for all actinides, major and minor, in the Evaluated Nuclear Data Library (ENDL) 2008 release, ENDL2008.

  18. Implementation of Energy-Dependent Q Values for Fission

    SciTech Connect

    Beck, B; Brown, D A; Daffin, F; Hedstrom, J; Vogt, R

    2007-08-08

    We discuss how the fission Q values for {sup 235}U, {sup 238}U and {sup 239}Pu depend on the energy of the incident neutron. We then describe how these values have been implemented in mcfgen etc. This paper describes the calculation of energy-dependent fission Q values by Madland [1] and explains how it has been implemented in the ENDL database for use in the LLNL codes.

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

    SciTech Connect

    Zeynalova, O. V.; Zeynalov, Sh.; Hambsch, F.-J.; Oberstedt, S.

    2010-11-25

    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.

  20. Student Experiments in Spontaneous Fission.

    ERIC Educational Resources Information Center

    Becchetti, F. D.; Ying, J. S.

    1981-01-01

    Advanced undergraduate experiments utilizing a commercially available, thin spontaneous fission source are described, including studies of the energy and mass distribution of the fission fragments and their energy and angular correlation. The experiments provide a useful introduction to fission, nuclear mass equations, heavy-ion physics, and…

  1. Non-equilibrium fission processes in intermediate energy nuclear collisions

    SciTech Connect

    Loveland, W.; Casey, C.; Xu, Z.; Seaborg, G.T.; Aleklett, K.; Sihver, L.

    1989-04-01

    We have measured the target fragment yields, angular and energy distributions for the interaction of 12-16 MeV/A/sup 32/S with /sup 165/Ho and /sup 197/Au and for the interaction of 32 and 44 MeV/A /sup 40/Ar with /sup 197/Au. The Au fission fragments associated with the peripheral collision peak in the folding angle distribution originate in a normal, ''slow'' fission process in which statistical equilibrium has been established. At the two lowest projectile energies, the Au fission fragments associated with the central collision peak in the folding angle distribution originate in part from ''fast'' (/tau//approximately//sup /minus/23/s), non-equilibrium processes. Most of the Ho fission fragments originate in non- equilibrium processes. The fast, non-equilibrium process giving rise to these fragments has many of the characteristics of ''fast fission'', but the cross sections associated with these fragments are larger than one would expect from current theories of ''fast fission. '' 14 refs., 8 figs.

  2. Recent advances in modeling fission cross sections over intermediate structures

    SciTech Connect

    Bouland, Olivier; Lynn, J. Eric; Talou, Patrick

    2009-01-01

    More accurate fission cross section calculations in presence of underlying intermediate structure are strongly desired. This paper recalls the common approximations used below the fission threshold and quantifies their impact. In particular, an exact expanded R-matrix Monte Carlo calculation of the intermediate structure, deeply mixed with the fluctuations of the class-I and II decay amplitudes, is shown. This paper also insists on the microscopic structure of the level densities as a function of the nucleus deformation and show preliminary neutron induced fission cross section calculations for {sup 239}Pu and {sup 240}Pu using newly calculated combinatorial level densities. Comparisons with recent evaluated and measured fission cross sections are made.

  3. Fission Product Monitoring of TRISO Coated Fuel For The Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John K. Hartwell; John b. Walter

    2010-10-01

    The US Department of Energy has embarked on a series of tests of TRISO-coated particle reactor fuel intended for use in the Very High Temperature Reactor (VHTR) as part of the Advanced Gas Reactor (AGR) program. The AGR-1 TRISO fuel experiment, currently underway, is the first in a series of eight fuel tests planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The AGR-1 experiment reached a peak compact averaged burn up of 9% FIMA with no known TRISO fuel particle failures in March 2008. The burnup goal for the majority of the fuel compacts is to have a compact averaged burnup greater than 18% FIMA and a minimum compact averaged burnup of 14% FIMA. At the INL the TRISO fuel in the AGR-1 experiment is closely monitored while it is being irradiated in the ATR. The effluent monitoring system used for the AGR-1 fuel is the Fission Product Monitoring System (FPMS). The FPMS is a valuable tool that provides near real-time data indicative of the AGR-1 test fuel performance and incorporates both high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based gross radiation monitors. To quantify the fuel performance, release-to-birth ratios (R/B’s) of radioactive fission gases are computed. The gamma-ray spectra acquired by the AGR-1 FPMS are analyzed and used to determine the released activities of specific fission gases, while a dedicated detector provides near-real time count rate information. Isotopic build up and depletion calculations provide the associated isotopic birth rates. This paper highlights the features of the FPMS, encompassing the equipment, methods and measures that enable the calculation of the release-to-birth ratios. Some preliminary results from the AGR-1 experiment are also presented.

  4. Fission Product Monitoring of TRISO Coated Fuel For The Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John K Hartwell; John B. Walter

    2008-09-01

    The US Department of Energy has embarked on a series of tests of TRISO-coated particle reactor fuel intended for use in the Very High Temperature Reactor (VHTR) as part of the Advanced Gas Reactor (AGR) program. The AGR-1 TRISO fuel experiment, currently underway, is the first in a series of eight fuel tests planned for irradiation in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The AGR-1 experiment reached a peak compact averaged burn up of 9% FIMA with no known TRISO fuel particle failures in March 2008. The burnup goal for the majority of the fuel compacts is to have a compact averaged burnup greater than 18% FIMA and a minimum compact averaged burnup of 14% FIMA. At the INL the TRISO fuel in the AGR-1 experiment is closely monitored while it is being irradiated in the ATR. The effluent monitoring system used for the AGR-1 fuel is the Fission Product Monitoring System (FPMS). The FPMS is a valuable tool that provides near real-time data indicative of the AGR-1 test fuel performance and incorporates both high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based gross radiation monitors. To quantify the fuel performance, release-to-birth ratios (R/B’s) of radioactive fission gases are computed. The gamma-ray spectra acquired by the AGR-1 FPMS are analyzed and used to determine the released activities of specific fission gases, while a dedicated detector provides near-real time count rate information. Isotopic build up and depletion calculations provide the associated isotopic birth rates. This paper highlights the features of the FPMS, encompassing the equipment, methods and measures that enable the calculation of the release-to-birth ratios. Some preliminary results from the AGR-1 experiment are also presented.

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

    SciTech Connect

    Grudzevich, O. T. Klinov, D. A.

    2013-07-15

    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.

  6. Establishing a Scientific Basis for Optimizing Compositions, Process Paths and Fabrication Methods for Nanostructured Ferritic Alloys for Use in Advanced Fission Energy Systems

    SciTech Connect

    Odette, G Robert; Cunningham, Nicholas J., Wu, Yuan; Etienne, Auriane; Stergar, Erich; Yamamoto, Takuya

    2012-02-21

    O3 concentration of 0.2 wt.%. An APT characterization of MA957 joined by friction stir welding (FSW) showed that this solid sate joining procedure had only a modest effect on the NF number density (N) and average diameter () compared to an as extruded sample. FSW appears to rearrange the NFs, which become highly aligned with sub-boundary and dislocation structures to an extent that are not observed in the as extruded case. The aligned NF structures are less apparent, but seem to persist after post weld annealing at 1150ºC for 3 h following which reduces N, consistent with a significant reduction in hardness. Lastly, several NFA materials, including MA957 and various 14YWT alloys, have been included in irradiation experiments performed at the Advanced Test Reactor, the JOYO sodium cooled fast reactor, the High Flux Isotope Reactor, and the SINQ spallation neut

  7. Advanced Monte Carlo modeling of prompt fission neutrons for thermal and fast neutron-induced fission reactions on Pu239

    NASA Astrophysics Data System (ADS)

    Talou, P.; Becker, B.; Kawano, T.; Chadwick, M. B.; Danon, Y.

    2011-06-01

    Prompt fission neutrons following the thermal and 0.5 MeV neutron-induced fission reaction of Pu239 are calculated using a Monte Carlo approach to the evaporation of the excited fission fragments. Exclusive data such as the multiplicity distribution P(ν), the average multiplicity as a function of fragment mass ν¯(A), and many others are inferred in addition to the most used average prompt fission neutron spectrum χ(Ein,Eout), as well as average neutron multiplicity ν¯. Experimental information on these more exclusive data help constrain the Monte Carlo model parameters. The calculated average total neutron multiplicity is ν¯c=2.871 in very close agreement with the evaluated value ν¯e=2.8725 present in the ENDF/B-VII.0 library. The neutron multiplicity distribution P(ν) is in very good agreement with the evaluation by Holden and Zucker. The calculated average spectrum differs in shape from the ENDF/B-VII.0 spectrum, evaluated with the Madland-Nix model. In particular, we predict more neutrons in the low-energy tail of the spectrum (below about 300 keV) than the Madland-Nix calculations, casting some doubts on how much scission neutrons contribute to the shape of the low-energy tail of the spectrum. The spectrum high-energy tail is very sensitive to the total kinetic energy distribution of the fragments as well as to the total excitation energy sharing at scission. Present experimental uncertainties on measured spectra above 6 MeV are too large to distinguish between various theoretical hypotheses. Finally, comparisons of the Monte Carlo results with experimental data on ν¯(A) indicate that more neutrons are emitted from the light fragments than the heavy ones, in agreement with previous works.

  8. Feasibility of Traveling Wave Direct Energy Conversion of Fission Reaction Fragments

    NASA Technical Reports Server (NTRS)

    Tarditi, A. G.; George, J. A.; Miley, G. H.; Scott, J. H.

    2013-01-01

    Fission fragment direct energy conversion has been considered in the past for the purpose of increasing nuclear power plant efficiency and for advanced space propulsion. Since the fragments carry electric charge (typically in the order of 20 e) and have 100 MeV-range kinetic energy, techniques utilizing very high-voltage DC electrodes have been considered. This study is focused on a different approach: the kinetic energy of the charged fission fragments is converted into alternating current by means of a traveling wave coupling scheme (Traveling Wave Direct Energy Converter, TWDEC), thereby not requiring the utilization of high voltage technology. A preliminary feasibility analysis of the concept is introduced based on a conceptual level study and on a particle simulation model of the beam dynamics.

  9. Energy dependence of the probability for asymmetric fission of /sup 213/At

    SciTech Connect

    Gruzintsev, E.N.; Itkis, M.G.; Okolovich, V.N.; Rusanov, A.Y.; Smirenkin, G.N.; Tolstikov, V.N.

    1982-10-20

    The mass distribution of the fragments of the fission of /sup 213/At in the reaction /sup 209/Bi(..cap alpha.., f) has been measured for ..cap alpha.. energies in the range 34.7--50 MeV. Over the entire energy range studied, the asymmetric mode is an improbable, slightly energy-dependent mode for the /sup 213/At fission. This property of the /sup 213/At fission represents a qualitative distinction from the fission of heavy nuclei.

  10. Phase 1 Space Fission Propulsion Energy Source Design

    NASA Technical Reports Server (NTRS)

    Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbud, Ivana; Carter, Robert; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    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 I" 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.

  11. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 2: Power from nuclear fission

    NASA Technical Reports Server (NTRS)

    Clement, J. D.

    1973-01-01

    Different types of nuclear fission reactors and fissionable materials are compared. Special emphasis is placed upon the environmental impact of such reactors. Graphs and charts comparing reactor facilities in the U. S. are presented.

  12. Laser Intertial Fusion Energy: Neutronic Design Aspects of a Hybrid Fusion-Fission Nuclear Energy System

    SciTech Connect

    Kramer, Kevin James

    2010-04-08

    This study investigates the neutronics design aspects of a hybrid fusion-fission energy system called the Laser Fusion-Fission Hybrid (LFFH). A LFFH combines current Laser Inertial Confinement fusion technology with that of advanced fission reactor technology to produce a system that eliminates many of the negative aspects of pure fusion or pure fission systems. When examining the LFFH energy mission, a significant portion of the United States and world energy production could be supplied by LFFH plants. The LFFH engine described utilizes a central fusion chamber surrounded by multiple layers of multiplying and moderating media. These layers, or blankets, include coolant plenums, a beryllium (Be) multiplier layer, a fertile fission blanket and a graphite-pebble reflector. Each layer is separated by perforated oxide dispersion strengthened (ODS) ferritic steel walls. The central fusion chamber is surrounded by an ODS ferritic steel first wall. The first wall is coated with 250-500 μm of tungsten to mitigate x-ray damage. The first wall is cooled by Li17Pb83 eutectic, chosen for its neutron multiplication and good heat transfer properties. The Li17Pb83 flows in a jacket around the first wall to an extraction plenum. The main coolant injection plenum is immediately behind the Li17Pb83, separated from the Li17Pb83 by a solid ODS wall. This main system coolant is the molten salt flibe (2LiF-BeF2), chosen for beneficial neutronics and heat transfer properties. The use of flibe enables both fusion fuel production (tritium) and neutron moderation and multiplication for the fission blanket. A Be pebble (1 cm diameter) multiplier layer surrounds the coolant injection plenum and the coolant flows radially through perforated walls across the bed. Outside the Be layer, a fission fuel layer comprised of depleted uranium contained in Tristructural-isotropic (TRISO) fuel particles

  13. Performance of the fissionTPC and the Potential to Advance the Thorium Fuel Cycle

    NASA Astrophysics Data System (ADS)

    Towell, Rusty; Niffte Collaboration

    2014-09-01

    The NIFFTE fission Time Projection Chamber (fissionTPC) is a powerful tool that is being developed to take precision measurements of neutron-induced fission cross sections of transuranic elements. During the last run at the Los Alamos Neutron Science Center (LANSCE) the fully instrumented TPC took data for the first time. The exquisite tracking capabilities of this device allow the full reconstruction of charged particles produced by neutron beam induced fissions from a thin central target. The wealth of information gained from this approach will allow cross section systematics to be controlled at the level of 1%. The fissionTPC performance from this run will be shared. These results are critical to the development of advanced uranium-fueled reactors. However, there are clear advantages to developing thorium-fueled reactors including the abundance of thorium verses uranium, minimizing radioactive waste, improved reactor safety, and enhanced proliferation resistance. The potential for using the fissionTPC to measure needed cross sections important to the development of thorium fueled nuclear reactors will also be discussed.

  14. Precise Nuclear Data Measurements Possible with the NIFFTE fissionTPC for Advanced Reactor Designs

    NASA Astrophysics Data System (ADS)

    Towell, Rusty; Niffte Collaboration

    2015-10-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) Collaboration has applied the proven technology of Time Projection Chambers (TPC) to the task of precisely measuring fission cross sections. With the NIFFTE fission TPC, precise measurements have been made during the last year at the Los Alamos Neutron Science Center from both U-235 and Pu-239 targets. The exquisite tracking capabilities of this device allow the full reconstruction of charged particles produced by neutron beam induced fissions from a thin central target. The wealth of information gained from this approach will allow systematics to be controlled at the level of 1%. The fissionTPC performance will be presented. These results are critical to the development of advanced uranium-fueled reactors. However, there are clear advantages to developing thorium-fueled reactors such as Liquid Fluoride Thorium Reactors over uranium-fueled reactors. These advantages include improved reactor safety, minimizing radioactive waste, improved reactor efficiency, and enhanced proliferation resistance. The potential for using the fissionTPC to measure needed cross sections important to the development of thorium-fueled reactors will also be discussed.

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

    SciTech Connect

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

    1980-10-01

    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.

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

    SciTech Connect

    Kadmensky, S. G. Titova, L. V.; Pen'kov, N. V.

    2006-08-15

    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.

  17. Potential Energy Calculations for Collinear Cluster Tripartition Fission Events

    NASA Astrophysics Data System (ADS)

    Unzhakova, A. V.; Pashkevich, V. V.; Pyatkov, Y. V.

    2014-09-01

    Strutinsky shell correction calculations were performed to describe the recent experimental results on collinear ternary fission. Collinear Cluster Tripartion fission events were studied experimentally in neutron induced fission of 235U, where the missing mass in the detected binary decay was suggested to characterize fission event as a collinear tripartition; and in spontaneous fission of 252Cf, where the direct detection of the three fission fragments has been used to confirm the existence of the Collinear Cluster Tripartition channel with a probability of 4.7×10-3 relative to the binary fission events.

  18. Fission Fragment Mass Distributions and Total Kinetic Energy Release of 235-Uranium and 238-Uranium in Neutron-Induced Fission at Intermediate and Fast Neutron Energies

    SciTech Connect

    Duke, Dana Lynn

    2015-11-12

    This Ph.D. dissertation describes a measurement of the change in mass distributions and average total kinetic energy (TKE) release with increasing incident neutron energy for fission of 235U and 238U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, En, changes the division of energy release in the resulting fission fragments, however, the details of energy partitioning remain ambiguous because the nucleus is a many-body quantum system. Creating a full theoretical model is difficult and experimental data to validate existing models are lacking. Additional fission measurements will lead to higher-quality models of the fission process, therefore improving applications such as the development of next-generation nuclear reactors and defense. This work also paves the way for precision experiments such as the Time Projection Chamber (TPC) for fission cross section measurements and the Spectrometer for Ion Determination in Fission (SPIDER) for precision mass yields.

  19. Fission Measurements with Dance

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Keksis, A. L.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Dashdorj, D.; Macri, R. A.; Parker, W. E.; Wilk, P. A.; Wu, C. Y.; Becker, J. A.; Angell, C. T.; Tonchev, A. P.; Baker, J. D.

    2008-08-01

    Neutron capture cross section measurements on actinides are complicated by the presence of neutron-induced fission. An efficient fission tagging detector used in coincidence with the Detector for Advanced Neutron Capture Experiments (DANCE) provides a powerful tool in undertaking simultaneous measurements of (n,γ) and (n,f) cross sections. Preliminary results on 235U(n,γ) and (n,f) and 242mAm(n,f) cross sections measured with DANCE and a custom fission-tagging parallel plate avalanche counter (PPAC) are presented. Additional measurements of γ-ray cluster multiplicity distributions for neutron-induced fission of 235U and 242mAm and spontaneous fission of 252Cf are shown, as well as γ-ray energy and average γ-ray energy distributions.

  20. Fission cross section calculations for 209Bi target nucleus based on fission reaction models in high energy regions

    NASA Astrophysics Data System (ADS)

    Kaplan, Abdullah; Capali, Veli; Ozdogan, Hasan

    2015-07-01

    Implementation of projects of new generation nuclear power plants requires the solving of material science and technological issues in developing of reactor materials. Melts of heavy metals (Pb, Bi and Pb-Bi) due to their nuclear and thermophysical properties, are the candidate coolants for fast reactors and accelerator-driven systems (ADS). In this study, α, γ, p, n and 3He induced fission cross section calculations for 209Bi target nucleus at high-energy regions for (α,f), (γ,f), (p,f), (n,f) and (3He,f) reactions have been investigated using different fission reaction models. Mamdouh Table, Sierk, Rotating Liquid Drop and Fission Path models of theoretical fission barriers of TALYS 1.6 code have been used for the fission cross section calculations. The calculated results have been compared with the experimental data taken from the EXFOR database. TALYS 1.6 Sierk model calculations exhibit generally good agreement with the experimental measurements for all reactions used in this study.

  1. Examining fine potential energy effects in high-energy fission dynamics

    NASA Astrophysics Data System (ADS)

    Mazurek, K.; Schmitt, C.; Nadtochy, P. N.; Kmiecik, M.; Maj, A.; Wasiak, P.; Wieleczko, J. P.

    2013-11-01

    The potential energy surface plays a decisive role in nuclear fission. Together with inertia and viscosity, it influences the trajectory of the system, and the properties of the fission fragments result from the puzzling interplay between static and dynamical effects. A careful study on the influence of the parametrization of the potential energy landscape in heavy-ion-induced fission is performed. Dynamical calculations are done within the stochastic Langevin approach in a three-dimensional deformation space. Various prescriptions of the potential energy surface are considered, probing two different Liquid Drop models and the deformation dependence of the Wigner/congruence energy. A wide set of observables, including cross sections, particle multiplicities, and integral, as well as isotopic and isobaric, distributions of fission and evaporation products, is analyzed. Nuclei close to the Businaro-Gallone point are confirmed to be well suited for investigating the Liquid Drop parametrization, while the influence of the deformation-dependent Wigner/congruence energy is difficult to demonstrate unambiguously in fission at high excitation energies.

  2. Benchmarking nuclear fission theory

    DOE PAGES

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

    2015-05-14

    We suggest a small set of fission observables to be used as test cases for validation of theoretical calculations. Thus, 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.

  3. Understanding Low Energy Gamma Emission from Fission and Capture with DANCE

    NASA Astrophysics Data System (ADS)

    Wilburn, Grey; Couture, Aaron; Mosby, Shea

    2012-10-01

    Los Alamos National Laboratory's Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 barium fluoride (BaF2) detectors in a 4π array used to study cross-section measurements from neutron capture reactions. Further, recent studies have taken advantage of DANCE to study the gamma emission from fission, which is not well characterized. Neutron capture is studied because of its relevance to nuclear astrophysics (almost all elements heavier than iron are formed via neutron capture) and nuclear energy, where neutron capture is a poison in the reactor. Gamma ray cascades following neutron capture and fission include photons with energies between 100 keV and 10 MeV. DANCE uses a ^6LiH sphere to attenuate scattered neutrons, the primary background in DANCE. Unfortunately, it also attenuates low energy gamma rays. In order to quantify this effect and validate simulations, direct measurements of low energy gammas were made with a high purity germanium (HPGe) crystal. HPGe's allow for high resolution measurements of low energy gamma rays that are not possible using the BaF2 crystals. The results and their agreement with simulations will be discussed.

  4. Dependence of Fission-Fragment Properties On Excitation Energy For Neutron-Rich Actinides

    NASA Astrophysics Data System (ADS)

    Ramos, D.; Rodríguez-Tajes, C.; Caamaño, M.; Farget, F.; Audouin, L.; Benlliure, J.; Casarejos, E.; Clement, E.; Cortina, D.; Delaune, O.; Derkx, X.; Dijon, A.; Doré, D.; Fernández-Domínguez, B.; de France, G.; Heinz, A.; Jacquot, B.; Navin, A.; Paradela, C.; Rejmund, M.; Roger, T.; Salsac, M. D.; Schmitt, C.

    2016-03-01

    Experimental access to full isotopic fragment distributions is very important to determine the features of the fission process. However, the isotopic identification of fission fragments has been, in the past, partial and scarce. A solution based on the use of inverse kinematics to study transfer-induced fission of exotic actinides was carried out at GANIL, resulting in the first experiment accessing the full identification of a collection of fissioning systems and their corresponding fission fragment distribution. In these experiments, a 238U beam at 6.14 AMeV impinged on a carbon target to produce fissioning systems from U to Am by transfer reactions, and Cf by fusion reactions. Isotopic fission yields of 250Cf, 244Cm, 240Pu, 239Np and 238U are presented in this work. With this information, the average number of neutrons as a function of the atomic number of the fragments is calculated, which reflects the impact of nuclear structure around Z=50, N=80 on the production of fission fragments. The characteristics of the Super Long, Standard I, Standard II, and Standard III fission channels were extracted from fits of the fragment yields for different ranges of excitation energy. The position and contribution of the fission channels as function of excitation energy are presented.

  5. The fusion fission and quasi-fission processes in the reaction 48Ca + 208Pb at energies near the Coulomb barrier

    NASA Astrophysics Data System (ADS)

    Prokhorova, E. V.; Bogachev, A. A.; Itkis, M. G.; Itkis, I. M.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Krupa, L.; Oganessian, Yu. Ts.; Pokrovsky, I. V.; Pashkevich, V. V.; Rusanov, A. Ya.

    2008-04-01

    Mass-energy distributions (MEDs) and capture-fission cross sections have been measured in the reaction 48Ca + 208Pb → 256No at the energies E=206-242 MeV using a double-arm time-of-flight spectrometer CORSET. It has been observed that MED of the fragments consists of two parts, namely, the classical fusion-fission process corresponding to the symmetric fission of 256No and quasi-fission "shoulders" corresponding to the light fragment masses ˜60-90 u and complimentary heavy fragment masses. The quasi-fission "shoulders" have a higher total kinetic energy (TKE) as compared with that expected for the classical fission. A mathematical formalism was employed for the MEDs fragment decomposition into fusion-fission and quasi-fission components. In the fusion-fission process a high-energy Super-Short mode has been discovered for the masses M=130-135 u and the TKE of ≈233 MeV.

  6. Advanced fossil energy utilization

    SciTech Connect

    Shekhawat, D.; Berry, D.; Spivey, J.; Pennline, H.; Granite, E.

    2010-01-01

    This special issue of Fuel is a selection of papers presented at the symposium ‘Advanced Fossil Energy Utilization’ co-sponsored by the Fuels and Petrochemicals Division and Research and New Technology Committee in the 2009 American Institute of Chemical Engineers (AIChE) Spring National Meeting Tampa, FL, on April 26–30, 2009.

  7. Fission Product Monitoring and Release Data for the Advanced Gas Reactor -1 Experiment

    SciTech Connect

    Dawn M. Scates; John B. Walter; Jason M. Harp; Mark W. Drigert; Edward L. Reber

    2010-10-01

    The AGR-1 experiment is a fueled multiple-capsule irradiation experiment that was irradiated in the Advanced Test Reactor (ATR) from December 26, 2006 until November 6, 2009 in support of the Very High Temperature Reactor (VHTR) Technology Development Office (TDO) Fuel Development and Qualification program. An important measure of the fuel performance is the quantification of the fission product releases over the duration of the experiment. To provide this data for the inert fission gasses(Kr and Xe), a fission product monitoring system (FPMS) was developed and implemented to monitor the individual capsule effluents for the radioactive species. The FPMS continuously measured the concentrations of various krypton and xenon isotopes in the sweep gas from each AGR-1 capsule to provide an indicator of fuel irradiation performance. Spectrometer systems quantified the concentrations of Kr-85m, Kr-87, Kr-88, Kr-89, Kr-90, Xe-131m, Xe-133, Xe 135, Xe 135m, Xe-137, Xe-138, and Xe-139 accumulated over repeated eight hour counting intervals.-. To determine initial fuel quality and fuel performance, release activity for each isotope of interest was derived from FPMS measurements and paired with a calculation of the corresponding isotopic production or birthrate. The release activities and birthrates were combined to determine Release-to-Birth ratios for the selected nuclides. R/B values provide indicators of initial fuel quality and fuel performance during irradiation. This paper presents a brief summary of the FPMS, the release to birth ratio data for the AGR-1 experiment and preliminary comparisons of AGR-1 experimental fuels data to fission gas release models.

  8. Advanced thermionic energy conversion

    NASA Technical Reports Server (NTRS)

    Britt, E. J.; Fitzpatrick, G. D.; Hansen, L. K.; Rasor, N. S.

    1974-01-01

    Basic analytical and experimental exploration was conducted on several types of advanced thermionic energy converters, and preliminary analysis was performed on systems utilizing advanced converter performance. The Pt--Nb cylindrical diode which exhibited a suppressed arc drop, as described in the preceding report, was reassembled and the existence of the postulated hydrid mode of operation was tentatively confirmed. Initial data obtained on ignited and unignited triode operation in the demountable cesium vapor system essentially confirmed the design principles developed in earlier work, with a few exceptions. Three specific advanced converter concepts were selected as candidates for concentrated basic study and for practical evaluation in fixed-configuration converters. Test vehicles and test stands for these converters and a unique controlled-atmosphere station for converter assembly and processing were designed, and procurement was initiated.

  9. Description of induced nuclear fission with Skyrme energy functionals. II. Finite temperature effects

    NASA Astrophysics Data System (ADS)

    Schunck, N.; Duke, D.; Carr, H.

    2015-03-01

    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 239Pu(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 the 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 a finite temperature nuclear density functional may provide a useful framework to obtain accurate predictions of fission fragment properties.

  10. Dynamical effects in fission investigated at high excitation energy

    NASA Astrophysics Data System (ADS)

    Benlliure, J.

    2016-05-01

    The experimental techniques used for the investigation of nuclear fission have progressed considerably during the last decade. Most of this progress is based on the use of the inverse kinematics technique allowing for the first time the complete isotopic and kinematic characterization of both fission fragments. These measurements make possible to characterize the fissioning system at saddle and at scission, and can be used to benchmark fission model calculations. One of the important ingredients in transport models describing the dynamics of the process is the dissipation parameter, governing the coupling between intrinsic and collective degrees of freedom. Recent experiments got access to the magnitude of this parameter and could also investigate its dependence in temperature and deformation.

  11. Neutron emission as a function of fragment energy in the spontaneous fission of /sup 260/Md

    SciTech Connect

    Wild, J.F.; van Aarle, J.; Westmeiser, W.; Lougheed, R.W.; Hulet, E.K.; Moody, K.J.; Dougan, R.J.; Brandt, R.; Patzelt, P.

    1989-04-19

    We have made the first measurement of the number of neutrons emitted in the spontaneous fission of a nuclide in which very high fragment energies dominate the fission process. In bombardments of /sup 254/Es, we produced 28-d /sup 260/Md, which was neutron-counted in a 1-m-diam spherical tank containing a Gd-doped scintillator solution. The average number of neutrons emitted per fission is only 2.58 +- 0.11, substantially less than for other actinides. A direct correlation of neutron multiplicity with fragment excitation energy is clearly demonstrated. 3 refs., 5 figs.

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

    SciTech Connect

    Grudzevich, O. T.; Yavshits, S. G.

    2013-03-15

    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.

  13. Fission Product Gamma-Ray Line Pairs Sensitive to Fissile Material and Neutron Energy

    SciTech Connect

    Marrs, R E; Norman, E B; Burke, J T; Macri, R A; Shugart, H A; Browne, E; Smith, A R

    2007-11-15

    The beta-delayed gamma-ray spectra from the fission of {sup 235}U, {sup 238}U, and {sup 239}Pu by thermal and near-14-MeV neutrons have been measured for delay times ranging from 1 minute to 14 hours. Spectra at all delay times contain sets of prominent gamma-ray lines with intensity ratios that identify the fissile material and distinguish between fission induced by low-energy or high-energy neutrons.

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

    SciTech Connect

    Kadmensky, S.G.

    2005-12-01

    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.

  15. Microscopic description of fission in neutron-rich radium isotopes with the Gogny energy density functional

    NASA Astrophysics Data System (ADS)

    Rodrıguez-Guzmán, R.; Robledo, L. M.

    2016-01-01

    Mean-field calculations, based on the D1S, D1N and D1M parametrizations of the Gogny energy density functional, have been carried out to obtain the potential energy surfaces relevant to fission in several Ra isotopes with the neutron number 144≤ N≤ 176. Inner and outer barrier heights as well as first and second isomer excitation energies are given. The existence of a well-developed third minimum along the fission paths of Ra nuclei is analyzed in terms of the energetics of the "fragments" defining such elongated configuration. The masses and charges of the fission fragments are studied as functions of the neutron number in the parent Ra isotope. The comparison between fission and α -decay half-lives, reveals that the former becomes faster for increasing neutron numbers. Though there exists a strong variance of the results with respect to the parameters used in the computation of the spontaneous fission rate, a change in tendency is observed at N=164 with a steady increase that makes heavier neutron-rich Ra isotopes stable against fission, diminishing the importance of fission recycling in the r-process.

  16. Advances in Nuclear Energy

    NASA Astrophysics Data System (ADS)

    Frois, B.

    2005-04-01

    This paper briefly reviews the next generations of nuclear reactors and the perspectives of development of nuclear energy. Advanced reactors will progressively replace the existing ones during the next two decades. Future systems of the fourth generation are planned to be built beyond 2030. These systems have been studied in the framework of the "Generation IV" International Forum. The goals of these systems is to have a considerable increase in safety, be economically competitive and produce a significantly reduced volume of nuclear wastes. The closed fuel cycle is preferred.

  17. Advanced Monte Carlo modeling of prompt fission neutrons for thermal and fast neutron-induced fission reactions on {sup 239}Pu

    SciTech Connect

    Talou, P.; Kawano, T.; Becker, B.; Danon, Y.; Chadwick, M. B.

    2011-06-15

    Prompt fission neutrons following the thermal and 0.5 MeV neutron-induced fission reaction of {sup 239}Pu are calculated using a Monte Carlo approach to the evaporation of the excited fission fragments. Exclusive data such as the multiplicity distribution P({nu}), the average multiplicity as a function of fragment mass {nu}-bar(A), and many others are inferred in addition to the most used average prompt fission neutron spectrum {chi}(E{sub in},E{sub out}), as well as average neutron multiplicity {nu}-bar. Experimental information on these more exclusive data help constrain the Monte Carlo model parameters. The calculated average total neutron multiplicity is {nu}-bar{sub c}=2.871 in very close agreement with the evaluated value {nu}-bar{sub e}=2.8725 present in the ENDF/B-VII.0 library. The neutron multiplicity distribution P({nu}) is in very good agreement with the evaluation by Holden and Zucker. The calculated average spectrum differs in shape from the ENDF/B-VII.0 spectrum, evaluated with the Madland-Nix model. In particular, we predict more neutrons in the low-energy tail of the spectrum (below about 300 keV) than the Madland-Nix calculations, casting some doubts on how much scission neutrons contribute to the shape of the low-energy tail of the spectrum. The spectrum high-energy tail is very sensitive to the total kinetic energy distribution of the fragments as well as to the total excitation energy sharing at scission. Present experimental uncertainties on measured spectra above 6 MeV are too large to distinguish between various theoretical hypotheses. Finally, comparisons of the Monte Carlo results with experimental data on {nu}-bar(A) indicate that more neutrons are emitted from the light fragments than the heavy ones, in agreement with previous works.

  18. Laser inertial fusion-based energy: Neutronic design aspects of a hybrid fusion-fission nuclear energy system

    NASA Astrophysics Data System (ADS)

    Kramer, Kevin James

    This study investigates the neutronics design aspects of a hybrid fusion-fission energy system called the Laser Fusion-Fission Hybrid (LFFH). A LFFH combines current Laser Inertial Confinement fusion technology with that of advanced fission reactor technology to produce a system that eliminates many of the negative aspects of pure fusion or pure fission systems. When examining the LFFH energy mission, a significant portion of the United States and world energy production could be supplied by LFFH plants. The LFFH engine described utilizes a central fusion chamber surrounded by multiple layers of multiplying and moderating media. These layers, or blankets, include coolant plenums, a beryllium (Be) multiplier layer, a fertile fission blanket and a graphite-pebble reflector. Each layer is separated by perforated oxide dispersion strengthened (ODS) ferritic steel walls. The central fusion chamber is surrounded by an ODS ferritic steel first wall. The first wall is coated with 250-500 mum of tungsten to mitigate x-ray damage. The first wall is cooled by Li17Pb83 eutectic, chosen for its neutron multiplication and good heat transfer properties. The Li17Pb 83 flows in a jacket around the first wall to an extraction plenum. The main coolant injection plenum is immediately behind the Li17Pb83, separated from the Li17Pb83 by a solid ODS wall. This main system coolant is the molten salt flibe (2LiF-BeF2), chosen for beneficial neutronics and heat transfer properties. The use of flibe enables both fusion fuel production (tritium) and neutron moderation and multiplication for the fission blanket. A Be pebble (1 cm diameter) multiplier layer surrounds the coolant injection plenum and the coolant flows radially through perforated walls across the bed. Outside the Be layer, a fission fuel layer comprised of depleted uranium contained in Tristructural-isotropic (TRISO) fuel particles having a packing fraction of 20% in 2 cm diameter fuel pebbles. The fission blanket is cooled by

  19. Assessing the role of the (n, γ f) process in the low-energy fission of actinides

    NASA Astrophysics Data System (ADS)

    Talou, Patrick; Lynn, J. E.; Kawano, T.; Mosby, S.; Couture, A.; Bouland, O.

    2016-06-01

    We review the role of the (n, γ f) process in the low-energy neutron-induced fission reaction of 239Pu. Recent measurements of the average total γ-ray energy released in this reaction were performed with the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos. Significant fluctuations of this quantity in the resonance region below 100 eV can be interpreted by invoking the presence of the indirect (n, γ f) process. Modern calculations of the probability for such an event to occur are presented.

  20. Energy dependence of mass, charge, isotopic, and energy distributions in neutron-induced fission of 235U and 239Pu

    NASA Astrophysics Data System (ADS)

    Pasca, H.; Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.; Kim, Y.

    2016-05-01

    The mass, charge, isotopic, and kinetic-energy distributions of fission fragments are studied within an improved scission-point statistical model in the reactions 235U+n and 239Pu+n at different energies of the incident neutron. The charge and mass distributions of the electromagnetic- and neutron-induced fission of 214,218Ra, 230,232,238U are also shown. The available experimental data are well reproduced and the energy-dependencies of the observable characteristics of fission are predicted for future experiments.

  1. Neutron-induced fission: properties of prompt neutron and γ rays as a function of incident energy

    NASA Astrophysics Data System (ADS)

    Stetcu, I.; Talou, P.; Kawano, T.

    2016-06-01

    We have applied the Hauser-Feshbach statistical theory, in a Monte-Carlo implementation, to the de-excitation of fission fragments, obtaining a reasonable description of the characteristics of neutrons and gamma rays emitted before beta decays toward stability. Originally implemented for the spontaneous fission of 252Cf and the neutroninduced fission of 235U and 239Pu at thermal neutron energy, in this contribution we discuss the extension of the formalism to incident neutron energies up to 20 MeV. For the emission of pre-fission neutrons, at incident energies beyond second-chance fission, we take into account both the pre-equilibrium and statistical pre-fission components. Phenomenological parameterizations of mass, charge and TKE yields are used to obtain the initial conditions for the fission fragments that subsequently decay via neutron and emissions. We illustrate this approach for 239Pu(n,f).

  2. Unusually low fragment energies in the symmetric fission of /sup 259/Md

    SciTech Connect

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

    1982-10-01

    The 103-min isotope /sup 259/Md has been identified as the daughter of an electron-capture decay branch of /sup 259/No produced via the /sup 248/Cm(/sup 18/O,..cap alpha..3n) reaction. Chemical separations were used to confirm the identity of /sup 259/Md, which decays by spontaneous fission. The kinetic energies of coincident fission fragments were measured, corresponding to a fragment mass which is highly symmetric, similar to those of /sup 258/Fm and /sup 259/Fm. However, the total kinetic energy distribution for /sup 259/Md is considerably broader (FWHM approx.60 MeV) than those of /sup 258/Fm and /sup 259/Fm, and peaks at 201 MeV, about 35--40 MeV lower in energy. Furthermore, the maximum total Kinetic energy of 215 MeV for mass-symmetric events is about 30 MeV lower than for similar events from the spontaneous fission of /sup 258/Fm and /sup 259/Fm. A hypothesis that this energy difference resulted from the emission of light, hydrogen-like particles at scission in a large fraction of /sup 259/Md spontaneous fission decays was shown to be unfounded. From experiments to observe such particles with counter telescopes, an upper limit of 5% was determined for the fraction of fission events accompanied by light-particle emission. The total kinetic energy deficit at mass symmetry must, therefore, be distributed between internal excitation energy and fragment deformation energy at scission. Although the presence of a large amount of fragment deformation energy seems incompatible with symmetric fission into spherical Sn-like fragments, we prefer this explanation because the low total kinetic energy suggests a lowered Coulomb energy resulting from greater separation of the charge centers of deformed fragments at scission.

  3. AMP-activated protein kinase mediates mitochondrial fission in response to energy stress

    PubMed Central

    Courchet, Julien; Lewis, Tommy L.; Losón, Oliver C.; Hellberg, Kristina; Young, Nathan P.; Chen, Hsiuchen; Polleux, Franck; Chan, David C.; Shaw, Reuben J.

    2016-01-01

    Mitochondria undergo fragmentation in response to electron transport chain (ETC) poisons and mitochondrial DNA–linked disease mutations, yet how these stimuli mechanistically connect to the mitochondrial fission and fusion machinery is poorly understood. We found that the energy-sensing adenosine monophosphate (AMP)–activated protein kinase (AMPK) is genetically required for cells to undergo rapid mitochondrial fragmentation after treatment with ETC inhibitors. Moreover, direct pharmacological activation of AMPK was sufficient to rapidly promote mitochondrial fragmentation even in the absence of mitochondrial stress. A screen for substrates of AMPK identified mitochondrial fission factor (MFF), a mitochondrial outer-membrane receptor for DRP1, the cytoplasmic guanosine triphosphatase that catalyzes mitochondrial fission. Nonphosphorylatable and phosphomimetic alleles of the AMPK sites in MFF revealed that it is a key effector of AMPK-mediated mitochondrial fission. PMID:26816379

  4. Studies on fission with ALADIN. Precise and simultaneous measurement of fission yields, total kinetic energy and total prompt neutron multiplicity at GSI

    NASA Astrophysics Data System (ADS)

    Martin, Julie-Fiona; Taieb, Julien; Chatillon, Audrey; Bélier, Gilbert; Boutoux, Guillaume; Ebran, Adeline; Gorbinet, Thomas; Grente, Lucie; Laurent, Benoit; Pellereau, Eric; Alvarez-Pol, Héctor; Audouin, Laurent; Aumann, Thomas; Ayyad, Yassid; Benlliure, Jose; Casarejos, Enrique; Cortina Gil, Dolores; Caamaño, Manuel; Farget, Fanny; Fernández Domínguez, Beatriz; Heinz, Andreas; Jurado, Beatriz; Kelić-Heil, Aleksandra; Kurz, Nikolaus; Nociforo, Chiara; Paradela, Carlos; Pietri, Stéphane; Ramos, Diego; Rodríguez-Sànchez, Jose-Luis; Rodríguez-Tajes, Carme; Rossi, Dominic; Schmidt, Karl-Heinz; Simon, Haik; Tassan-Got, Laurent; Vargas, Jossitt; Voss, Bernd; Weick, Helmut

    2015-12-01

    A novel technique for fission studies, based on the inverse kinematics approach, is presented. Following pioneering work in the nineties, the SOFIA Collaboration has designed and built an experimental set-up dedicated to the simultaneous measurement of isotopic yields, total kinetic energies and total prompt neutron multiplicities, by fully identifying both fission fragments in coincidence, for the very first time. This experiment, performed at GSI, permits to study the fission of a wide variety of fissioning systems, ranging from mercury to neptunium, possibly far from the valley of stability. A first experiment, performed in 2012, has provided a large array of unprecedented data regarding the nuclear fission process. An excerpt of the results is presented. With this solid starter, further improvements of the experimental set-up are considered, which are consistent with the expected developments at the GSI facility, in order to measure more fission observables in coincidence. The completeness reached in the SOFIA data, permits to scrutinize the correlations between the interesting features of fission, offering a very detailed insight in this still unraveled mechanism.

  5. DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JANUARY 1, 2002 THROUGH MARCH 31, 2002

    SciTech Connect

    L.C. BROWN

    2002-03-31

    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.

  6. Recent Advances in Power Conversion and Heat Rejection Technology for Fission Surface Power

    NASA Technical Reports Server (NTRS)

    Mason, Lee

    2010-01-01

    Under the Exploration Technology Development Program, the National Aeronautics and Space Administration (NASA) and the Department of Energy (DOE) are jointly developing Fission Surface Power (FSP) technology for possible use in human missions to the Moon and Mars. A preliminary reference concept was generated to guide FSP technology development. The concept consists of a liquid-metal-cooled reactor, Stirling power conversion, and water heat rejection, with Brayton power conversion as a backup option. The FSP project has begun risk reduction activities on some key components with the eventual goal of conducting an end-to-end, non-nuclear, integrated system test. Several power conversion and heat rejection hardware prototypes have been built and tested. These include multi-kilowatt Stirling and Brayton power conversion units, titanium-water heat pipes, and composite radiator panels.

  7. Probing energy dissipation, γ-ray and neutron multiplicity in the thermal neutron-induced fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Pahlavani, M. R.; Mirfathi, S. M.

    2016-04-01

    The incorporation of the four-dimensional Langevin equations led to an integrative description of fission cross-section, fragment mass distribution and the multiplicity and energy distribution of prompt neutrons and γ-rays in the thermal neutron-induced fission of 239Pu. The dynamical approach presented in this paper thoroughly reproduces several experimental observables of the fission process at low excitation energy.

  8. Decay heat and anti-neutrino energy spectra in fission fragments from total absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Rykaczewski, Krzysztof

    2015-10-01

    Decay studies of over forty 238U fission products have been studied using ORNL's Modular Total Absorption Spectrometer. The results are showing increased decay heat values, by 10% to 50%, and the energy spectra of anti-neutrinos shifted towards lower energies. The latter effect is resulting in a reduced number of anti-neutrinos interacting with matter, often by tens of percent per fission product. The results for several studied nuclei will be presented and their impact on decay heat pattern in power reactors and reactor anti-neutrino physics will be discussed.

  9. Effects of Fission Yield Data in the Calculation of Antineutrino Spectra for ^{235}U(n,fission) at Thermal and Fast Neutron Energies.

    PubMed

    Sonzogni, A A; McCutchan, E A; Johnson, T D; Dimitriou, P

    2016-04-01

    Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 ^{235}U fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of ^{86}Ge generates an excess of antineutrinos at 5-7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0-7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel. PMID:27081973

  10. Effects of Fission Yield Data in the Calculation of Antineutrino Spectra for 235U (n ,fission) at Thermal and Fast Neutron Energies

    NASA Astrophysics Data System (ADS)

    Sonzogni, A. A.; McCutchan, E. A.; Johnson, T. D.; Dimitriou, P.

    2016-04-01

    Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 235U 235 fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of 86Ge generates an excess of antineutrinos at 5-7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0-7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel.

  11. Effects of Fission Yield Data in the Calculation of Antineutrino Spectra for ^{235}U(n,fission) at Thermal and Fast Neutron Energies.

    PubMed

    Sonzogni, A A; McCutchan, E A; Johnson, T D; Dimitriou, P

    2016-04-01

    Fission yields form an integral part of the prediction of antineutrino spectra generated by nuclear reactors, but little attention has been paid to the quality and reliability of the data used in current calculations. Following a critical review of the thermal and fast ENDF/B-VII.1 ^{235}U fission yields, deficiencies are identified and improved yields are obtained, based on corrections of erroneous yields, consistency between decay and fission yield data, and updated isomeric ratios. These corrected yields are used to calculate antineutrino spectra using the summation method. An anomalous value for the thermal fission yield of ^{86}Ge generates an excess of antineutrinos at 5-7 MeV, a feature which is no longer present when the corrected yields are used. Thermal spectra calculated with two distinct fission yield libraries (corrected ENDF/B and JEFF) differ by up to 6% in the 0-7 MeV energy window, allowing for a basic estimate of the uncertainty involved in the fission yield component of summation calculations. Finally, the fast neutron antineutrino spectrum is calculated, which at the moment can only be obtained with the summation method and may be relevant for short baseline reactor experiments using highly enriched uranium fuel.

  12. Flowsheet Testing of the Fission Product Extraction Process as Part of Advanced Aqueous Reprocessing

    SciTech Connect

    Jack Law; Dean R. Peterman; catherine Riddle; David H. Meikrantz; Terry Todd

    2007-06-01

    As part of the Advanced Fuel Cycle Initiative (AFCI), the reduction in volume and heat generation of spent nuclear fuel requiring geologic disposal is currently being addressed. The goal is to optimize utilization of the nation’s first repository and potentially reduce or eliminate the need for additional repositories. This will be achieved through separating long-lived, highly toxic elements, reducing high-level waste volumes and the toxicity of spent nuclear fuel, and reducing the heat generation of spent nuclear fuel. The Idaho National Laboratory (INL) is working closely with a team of national laboratories and other organizations to support development of these separations processes. Key to the reduction of short-term heat load in a geological repository is the separation of 137Cs and 90Sr. Removal of these highly radioactive fission products reduces the short-term (~100 yr) heat generation source of the spent nuclear fuel. Once separated, the Cs and Sr would be placed in storage until the activity has decayed to LLW levels, at which time it could potentially be disposed of as a non-transuranic (TRU) low-level waste (LLW).

  13. Advanced electron microscopic techniques applied to the characterization of irradiation effects and fission product identification of irradiated TRISO coated particles from the AGR-1 experiment

    SciTech Connect

    Rooyen, I.J. van; Lillo, T.M.; Trowbridge, T.L.; Madden, J.M.; Wu, Y.Q.; Goran, D.

    2013-07-01

    Preliminary electron microscopy of coated fuel particles from the AGR-1 experiment was conducted using characterization techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and wavelength dispersive spectroscopy (WDS). Microscopic quantification of fission-product precipitates was performed. Although numerous micro- and nano-sized precipitates observed in the coating layers during initial SEM characterization of the cross-sections, and in subsequent TEM diffraction patterns, were indexed as UPd{sub 2}Si{sub 2}, no Ag was conclusively found. Additionally, characterization of these precipitates highlighted the difficulty of measuring low concentrations of Ag in precipitates in the presence of significantly higher concentrations of Pd and U. The electron microscopy team followed a multi-directional and phased approach in the identification of fission products in irradiated TRISO fuel. The advanced electron microscopy techniques discussed in this paper, not only demonstrate the usefulness of the equipment (methods) as relevant research tools, but also provide relevant scientific results which increase the knowledge about TRISO fuel particles microstructure and fission products transport.

  14. Energy dependence of nuclear charge distribution in neutron induced fission of Z-even nuclei

    NASA Astrophysics Data System (ADS)

    Roshchenko, V. A.; Piksaikin, V. M.; Isaev, S. G.; Goverdovski, A. A.

    2006-07-01

    For the first time the distribution of nuclear charge of fission products with mass numbers 87, 88, 89, 91, 93, 94, 95, 137, 138, 139, and 140 and their complementary products have been studied for neutron induced fission of U235 and Pu239 in the energy range from thermal up to 1.2 MeV. The energy dependences of the cumulative yields of Br87, Br88, Br89, Br91, Kr93, Rb94, Rb95, I137, I138, I139, and I140 have been obtained by delayed neutron measurements. The most probable charge ZP(A)in the appropriate isobaric β-decay chains was estimated. The results were analyzed in terms of the deviation ΔZP(A') of the most probable charge of isobaric β-decay chains from the unchanged charge distribution before prompt neutron emission (nuclear charge polarization) and they are compared with experimental data of other authors and with predictions from Nethaway's ZP-formula and Wahl's ZP-model. We show that the nuclear charge polarization of primary fission fragments <ΔZP(A')> before prompt neutron evaporation decreases as the excitation energy of the compound nucleus increases. This decrease is more pronounced for fission of U235. The energy dependencies of ΔZP(A') and ΔZP(ZP) obtained in the present work show an attenuation of the odd-even effects in the charge distribution as the excitation energy of the compound nucleus increases.

  15. Advances in Development of the Fission Product Extraction Process for the Separation of Cesium and Strontium from Spent Nuclear Fuel

    SciTech Connect

    JAck D. Law

    2007-09-01

    The Fission Product Extraction (FPEX) Process is being developed as part of the United States Department of Energy Advanced Fuel Cycle Initiative for the simultaneous separation of cesium (Cs) and strontium (Sr) from spent light water reactor (LWR) fuel. Separation of the Cs and Sr will reduce the short-term heat load in a geological repository, and when combined with the separation of americium (Am) and curium (Cm), could increase the capacity of the geological repository by a factor of approximately 100. The FPEX process is based on two highly specific extractants: 4,4',(5')-Di-(t-butyldicyclo-hexano)-18-crown-6 (DtBuCH18C6) and Calix[4]arene-bis-(tert-octylbenzo-crown-6) (BOBCalixC6). The DtBuCH18C6 extractant is selective for strontium and the BOBCalixC6 extractant is selective for cesium. Results of flowsheet testing of the FPEX process with a simulated feed solution in 3.3-cm centrifugal contactors are detailed. Removal efficiencies, distribution coefficient data, coextraction of metals, and process hydrodynamic performance are discussed along with recommendations for future flowsheet testing with actual spent nuclear fuel.

  16. Fission Technology for Exploring and Utilizing the Solar System

    NASA Technical Reports Server (NTRS)

    Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbub, Ivana; Schmidt, George R. (Technical Monitor)

    2000-01-01

    Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include bimodal nuclear thermal rockets, high specific energy propulsion systems, and pulsed fission propulsion systems. In-space propellant re-supply enhances the effective performance of all systems, but requires significant infrastructure development. Safe, timely, affordable utilization of first-generation space fission propulsion systems will enable the development of more advanced systems. First generation space systems will build on over 45 years of US and international space fission system technology development to minimize cost,

  17. Space Fission Propulsion System Development Status

    NASA Technical Reports Server (NTRS)

    Houts, M.; Van Dyke, M. K.; Godfroy, T. J.; Pedersen, K. W.; Martin, J. J.; Dickens, R.; Williams, E.; Harper, R.; Salvail, P.; Hrbud, I.

    2001-01-01

    The world's first man-made self-sustaining fission reaction was achieved in 1942. Since then fission has been used to propel submarines, generate tremendous amounts of electricity, produce medical isotopes, and provide numerous other benefits to society. Fission systems operate independently of solar proximity or orientation, and are thus well suited for deep space or planetary surface missions. In addition, the fuel for fission systems (enriched uranium) is virtually non-radioactive. The primary safety issue with fission systems is avoiding inadvertent system start. Addressing this issue through proper system design is straight-forward. Despite the relative simplicity and tremendous potential of space fission systems, the development and utilization of these systems has proven elusive. The first use of fission technology in space occurred 3 April 1965 with the US launch of the SNAP-10A reactor. There have been no additional US uses of space fission systems. While space fission systems were used extensively by the former Soviet Union, their application was limited to earth-orbital missions. Early space fission systems must be safely and affordably utilized if we are to reap the benefits of advanced space fission systems. NASA's Marshall Space Flight Center, working with Los Alamos National Laboratory (LANL), Sandia National Laboratories, and others, has conducted preliminary research related to a Safe Affordable Fission Engine (SAFE). An unfueled core has been fabricated by LANL, and resistance heaters used to verify predicted core thermal performance by closely mimicking heat from fission. The core is designed to use only established nuclear technology and be highly testable. In FY01 an energy conversion system and thruster will be coupled to the core, resulting in an 'end-to-end' nuclear electric propulsion demonstrator being tested using resistance heaters to closely mimic heat from fission. Results of the SAFE test program will be presented. The applicability

  18. Mini Fission-Fusion-Fission Explosions (Mini-Nukes). A Third Way Towards the Controlled Release of Nuclear Energy by Fission and Fusion

    NASA Astrophysics Data System (ADS)

    Winterberg, F.

    2004-06-01

    Chemically ignited nuclear microexplosions with a fissile core, a DT reflector and U238 (Th232) pusher, offer a promising alternative to magnetic and inertial confinement fusion, not only burning DT, but in addition U238 (or Th232), and not depending on a large expensive laser of electric pulse power supply. The prize to be paid is a gram size amount of fissile material for each microexplosion, but which can be recovered by breeding in U238. In such a "mini-nuke" the chemical high explosive implodes a spherical metallic shell onto a smaller shell, with the smaller shell upon impact becoming the source of intense black body radiation which vaporizes the ablator of a spherical U238 (Th232) pusher, with the pusher accelerated to a velocity of ˜200 km/s, sufficient to ignite the DT gas placed in between the pusher and fissile core, resulting in a fast fusion neutron supported fission reaction in the core and pusher. Estimates indicate that a few kg of high explosives are sufficient to ignite such a "mini-nuke", with a gain of ˜103, releasing an energy equivalent to a few tons of TNT, still manageable for the microexplosion to be confined in a reactor vessel. A further reduction in the critical mass is possible by replacing the high explosive with fast moving solid projectiles. For light gas gun driven projectiles with a velocity of ˜ 10 km/s, the critical mass is estimated to be 0.25 g, and for magnetically accelerated 25 km/s projectiles it is as small as ˜ 0.05 g. With the much larger implosion velocities, reached by laser- or particle beam bombardment of the outer shell, the critical mass can still be much smaller with the fissile core serving as a fast ignitor. Increasing the implosion velocity decreases the overall radius of the fission-fusion assembly in inverse proportion to this velocity, for the 10 km/s light gas gun driven projectiles from 10 cm to 5 cm, for the 25 km/s magnetically projectiles down to 2 cm, and still more for higher implosion velocities.

  19. Impact of low-energy photons on the characteristics of prompt fission γ -ray spectra

    NASA Astrophysics Data System (ADS)

    Oberstedt, A.; Billnert, R.; Hambsch, F.-J.; Oberstedt, S.

    2015-07-01

    In this paper we report on a new study of prompt γ -rays from the spontaneous fission of 252Cf . Photons were measured in coincidence with fission fragments by employing four different lanthanide halide scintillation detectors. Together with results from a previous work of ours, we determined characteristic parameters with high precision, such as the average γ -ray multiplicity ν¯γ=(8.29 ±0.13 ), the average energy per photon ɛγ=(0.80 ±0.02 ) MeV, and the total γ -ray energy release per fission Eγ ,tot=(6.65 ±0.10 ) MeV. The excellent agreement between the individual results obtained in all six measurements proves the good repeatability of the applied experimental technique. The impact of low-energy photons, i.e., below 500 keV, on prompt fission γ -ray spectra characteristics has been investigated as well by comparing our results with those taken with the DANCE detector system, which appears to suffer from absorption effects in the low-energy region. Correction factors for this effect were estimated, giving results comparable to ours as well as to historical ones. From this we demonstrate that the different techniques of determining the average γ -ray multiplicity, either from a properly measured and normalized spectrum or a measured multiplicity distribution, give equivalent and consistent results.

  20. Bremsstrahlung emission of high energy accompanying spontaneous fission of {sup 252}Cf

    SciTech Connect

    Maydanyuk, S. P.; Olkhovsky, V. S.; Mandaglio, G.; Manganaro, M.; Fazio, G.; Giardina, G.

    2010-07-15

    The study of the bremsstrahlung photon emission accompanying fragments produced in the spontaneous fission of heavy nuclei by a fully quantum approach is presented for the first time. This kind of problem requires the knowledge of wave functions of the fissioning system leading to a wide distribution of couples of fragments that are the products of fission. With the aim of obtaining these wave functions, the interaction potential between the emitted fragment and residual nucleus is calculated by a standard approach. A new procedure was performed that allows an increase in the accuracy of calculations of radial integrals in the far asymptotic region and the achievement of the convenient convergence in calculations of the spectra. The total probability of the emitted photons in the spontaneous fission of {sup 252}Cf was calculated in such a way. We obtained good agreement between theory and experimental data up to 38 MeV for the bremsstrahlung spectrum of photons while the calculation of the total probability of photon emission accompanying fragments was performed up to an energy of 60 MeV. The analysis of contributions in the bremsstrahlung spectrum accompanying the emission of light, medium, and heavy fragments in the fission of {sup 252}Cf is presented.

  1. Ohio Advanced Energy Manufacturing Center

    SciTech Connect

    Kimberly Gibson; Mark Norfolk

    2012-07-30

    The program goal of the Ohio Advanced Energy Manufacturing Center (OAEMC) is to support advanced energy manufacturing and to create responsive manufacturing clusters that will support the production of advanced energy and energy-efficient products to help ensure the nation's energy and environmental security. This goal cuts across a number of existing industry segments critical to the nation's future. Many of the advanced energy businesses are starting to make the transition from technology development to commercial production. Historically, this transition from laboratory prototypes through initial production for early adopters to full production for mass markets has taken several years. Developing and implementing manufacturing technology to enable production at a price point the market will accept is a key step. Since these start-up operations are configured to advance the technology readiness of the core energy technology, they have neither the expertise nor the resources to address manufacturing readiness issues they encounter as the technology advances toward market entry. Given the economic realities of today's business environment, finding ways to accelerate this transition can make the difference between success and failure for a new product or business. The advanced energy industry touches a wide range of industry segments that are not accustomed to working together in complex supply chains to serve large markets such as automotive and construction. During its first three years, the Center has catalyzed the communication between companies and industry groups that serve the wide range of advanced energy markets. The Center has also found areas of common concern, and worked to help companies address these concerns on a segment or industry basis rather than having each company work to solve common problems individually. EWI worked with three industries through public-private partnerships to sew together disparate segments helping to promote overall industry

  2. Dynamical Aspects of Nuclear Fission

    NASA Astrophysics Data System (ADS)

    Kliman, J.; Itkis, M. G.; Gmuca, Š.

    2008-11-01

    Fission dynamics. Dependence of scission-neutron yield on light-fragment mass for [symbol]=1/2 [et al.]. Dynamics of capture quasifission and fusion-fission competition / L. Stuttgé ... [et al.] -- Fission-fission. The processes of fusion-fission and quasi-fission of superheavy nuclei / M. G. Itkis ... [et al.]. Fission and quasifission in the reactions [symbol]Ca+[symbol]Pb and [symbol]Ni+[symbol]W / G. N. Knyazheva ... [et al.]. Mass-energy characteristics of reactions [symbol]Fe+[symbol][symbol][symbol]266Hs and [symbol]Mg+[symbol]Cm[symbol][symbol]Hs at Coulomb barrier / L. Krupa ... [et al.]. Fusion of heavy ions at extreme sub-barrier energies / Ş. Mişicu and H. Esbensen. Fusion and fission dynamics of heavy nuclear system / V. Zagrebaev and W. Greiner. Time-dependent potential energy for fusion and fission processes / A. V. Karpov ... [et al.] -- Superheavy elements. Advances in the understanding of structure and production mechanisms for superheavy elements / W. Greiner and V. Zagrebaev. Fission barriers of heaviest nuclei / A. Sobiczewski ... [et al.]. Possibility of synthesizing doubly magic superheavy nuclei / Y Aritomo ... [et al.]. Synthesis of superheavy nuclei in [symbol]Ca-induced reactions / V. K. Utyonkov ... [et al.] -- Fragmentation. Production of neutron-rich nuclei in the nucleus-nucleus collisions around the Fermi energy / M. Veselský. Signals of enlarged core in [symbol]Al / Y. G. Ma ... [et al.] -- Exotic modes. New insight into the fission process from experiments with relativistic heavy-ion beams / K.-H. Schmidt ... [et al.]. New results for the intensity of bimodal fission in binary and ternary spontaneous fission of [symbol]Cf / C. Goodin ... [et al.]. Rare fission modes: study of multi-cluster decays of actinide nuclei / D. V. Kamanin ... [et al.]. Energy distribution of ternary [symbol]-particles in [symbol]Cf(sf) / M. Mutterer ... [et al.]. Preliminary results of experiment aimed at searching for collinear cluster tripartition of

  3. Advanced Performance Hydraulic Wind Energy

    NASA Technical Reports Server (NTRS)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  4. Advances in energy technology

    SciTech Connect

    Sauer, H.J. Jr.; Hegler, B.E.

    1982-01-01

    Papers on various topics of energy conservation, new passive solar heating and storage devices, governmental particiaption in developing energy technologies, and the development of diverse energy sources and safety features are presented. Attention is given to recent shifts in the federal and state government roles in energy research, development and economic incentives. The applications of passive solar walls, flat plate collectors and trombe walls as retorfits for houses, institutions, and industries were examined. Attention was given to the implementation of wind power by a zoo and the use of spoilers as speed control devices in a Darrieus wind turbine. Aspects of gasohol, coal, synfuel, and laser-pyrolyzed coal products use are investigated. Finally, the economic, social, and political factors influencing energy system selection are explored, together with conservation practices in housing, government, and industry, and new simulators for enhancing nuclear power plant safety.

  5. FITPULS: a code for obtaining analytic fits to aggregate fission-product decay-energy spectra. [In FORTRAN

    SciTech Connect

    LaBauve, R.J.; George, D.C.; England, T.R.

    1980-03-01

    The operation and input to the FITPULS code, recently updated to utilize interactive graphics, are described. The code is designed to retrieve data from a library containing aggregate fine-group spectra (150 energy groups) from fission products, collapse the data to few groups (up to 25), and fit the resulting spectra along the cooling time axis with a linear combination of exponential functions. Also given in this report are useful results for aggregate gamma and beta spectra from the decay of fission products released from /sup 235/U irradiated with a pulse (10/sup -4/ s irradiation time) of thermal neutrons. These fits are given in 22 energy groups that are the first 22 groups of the LASL 25-group decay-energy group structure, and the data are expressed both as MeV per fission second and particles per fission second; these pulse functions are readily folded into finite fission histories. 65 figures, 11 tables.

  6. Angular distributions and anisotropy of the fission fragments from neutron-induced fission of 233U and 209Bi in intermediate energy range 1-200 MeV

    NASA Astrophysics Data System (ADS)

    Vorobyev, A. S.; Gagarski, A. M.; Shcherbakov, O. A.; Vaishnene, L. A.; Barabanov, A. L.

    2016-09-01

    New results of the neutron-induced fission experiments carried out at the neutron time-of-flight spectrometer GNEIS of the PNPI are given. Angular distributions of fission fragments from the neutron-induced fission of 233U and 209Bi nuclei have been measured in the energy range 1-200 MeV using position sensitive multiwire proportional counters as fission fragment detector. The recent improvements of the measurement and data processing procedures are described. The data on anisotropy of fission fragments deduced from the measured angular distributions are presented in comparison with the experimental data of other authors.

  7. Fission fragment charge and mass distributions in 239Pu(n, f ) in the adiabatic nuclear energy density functional theory

    DOE PAGES

    Regnier, D.; Dubray, N.; Schunck, N.; Verriere, M.

    2016-05-13

    Here, accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics.

  8. Shape of spectra and mean energies of prompt fission neutrons from {sup 237}Np fission induced by primary neutrons of energy in the range E{sub n} < 20 MeV

    SciTech Connect

    Svirin, M. I.

    2008-10-15

    An analysis of the spectrum of prompt neutrons originating from {sup 237}Np fission induced by primary neutrons of energy E{sub n} = 14.7 MeV confirms the results obtained previously for {sup 232}Th (E{sub n} = 14.7, 17.7 MeV), {sup 235}U (14.7 MeV), and {sup 238}U (13.2, 14.7, 16, and 17.7 MeV) nuclei. In the experimental spectrum measured in the emissive fission of {sup 237}Np, there is also an excess of soft neutrons in the energy range E < 2 MeV in relation to what follows from a traditional theoretical description that considers two sources of prompt fission neutrons: fully accelerated fission fragments and excited nuclei prior to their separation. In just the same way as in the cases of {sup 232}Th and {sup 235,238}U, the shape of the prompt-fission-neutron spectrum for {sup 237}Np is reproduced theoretically over the entire measured range of secondary-neutron energies upon including nonaccelerated fragments as a third source of neutrons in the computational scheme. A description of the spectra and mean energies of prompt fission neutrons versus the bombarding-neutron energy is obtained on the basis of experimental data and their analysis. The results on mean energies are compared with data on the proton-induced fission of {sup 236,238}U nuclei.

  9. On the role of energy separated in fission process, excitation energy and reaction channels effects in the isomeric ratios of fission product 135Xe in photofission of actinide elements

    NASA Astrophysics Data System (ADS)

    Thiep, Tran Duc; An, Truong Thi; Cuong, Phan Viet; Vinh, Nguyen The; Mishinski, G. V.; Zhemenik, V. I.

    2016-07-01

    In this work we present the isomeric ratio of fission product 135Xe in the photo-fission of actinide elements 232Th, 233U and 237Np induced by end-point bremsstrahlung energies of 13.5, 23.5 and 25.0 MeV which were determined by the method of inert gaseous flow. The data were analyzed, discussed and compared with the similar data from literature to examine the role of energy separated in fission process, excitation energy and reaction channels effects.

  10. Unfolding the fission prompt gamma-ray energy and multiplicity distribution measured by DANCE

    SciTech Connect

    Chyzh, A; Wu, C Y; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J; Laptev, A

    2010-10-16

    The nearly energy independence of the {gamma}-ray efficiency and multiplicity response for the DANCE array, the unusual characteristic elucidated in our early technical report (LLNL-TR-452298), gives one a unique opportunity to derive the true prompt {gamma}-ray energy and multiplicity distribution in fission from the measurement. This unfolding procedure for the experimental data will be described in details and examples will be given to demonstrate the feasibility of reconstruction of the true distribution.

  11. Advanced materials for energy storage.

    PubMed

    Liu, Chang; Li, Feng; Ma, Lai-Peng; Cheng, Hui-Ming

    2010-02-23

    Popularization of portable electronics and electric vehicles worldwide stimulates the development of energy storage devices, such as batteries and supercapacitors, toward higher power density and energy density, which significantly depends upon the advancement of new materials used in these devices. Moreover, energy storage materials play a key role in efficient, clean, and versatile use of energy, and are crucial for the exploitation of renewable energy. Therefore, energy storage materials cover a wide range of materials and have been receiving intensive attention from research and development to industrialization. In this Review, firstly a general introduction is given to several typical energy storage systems, including thermal, mechanical, electromagnetic, hydrogen, and electrochemical energy storage. Then the current status of high-performance hydrogen storage materials for on-board applications and electrochemical energy storage materials for lithium-ion batteries and supercapacitors is introduced in detail. The strategies for developing these advanced energy storage materials, including nanostructuring, nano-/microcombination, hybridization, pore-structure control, configuration design, surface modification, and composition optimization, are discussed. Finally, the future trends and prospects in the development of advanced energy storage materials are highlighted.

  12. Theoretical Description of the Fission Process

    SciTech Connect

    Witold Nazarewicz

    2009-10-25

    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

  13. Seminar on Fission VI

    NASA Astrophysics Data System (ADS)

    Wagemans, Cyriel; Wagemans, Jan; D'Hondt, Pierre

    2008-04-01

    Topical reviews. Angular momentum in fission / F. Gönnenwein ... [et al.]. The processes of fusion-fission and quasi-fission of heavy and super-heavy nuclei / M. G. Itkis ... [et al.] -- Fission cross sections and fragment properties. Minor-actinides fission cross sections and fission fragment mass yields via the surrogate reaction technique / B. Jurado ... [et al.]. Proton-induced fission on actinide nuclei at medium energy / S. Isaev ... [et al.]. Fission cross sections of minor actinides and application in transmutation studies / A. Letourneau ... [et al.]. Systematics on even-odd effects in fission fragments yields: comparison between symmetric and asymmetric splits / F. Rejmund, M Caamano. Measurement of kinetic energy distributions, mass and isotopic yields in the heavy fission products region at Lohengrin / A. Bail ... [et al.] -- Ternary fission. On the Ternary [symbol] spectrum in [symbol]Cf(sf) / M. Mutterer ... [et al.]. Energy degrader technique for light-charged particle spectroscopy at LOHENGRIN / A. Oberstedt, S. Oberstedt, D. Rochman. Ternary fission of Cf isotopes / S. Vermote ... [et al.]. Systematics of the triton and alpha particle emission in ternary fission / C. Wagemans, S. Vermote, O. Serot -- Neutron emission in fission. Scission neutron emission in fission / F.-J. Hambsch ... [et al.]. At and beyond the Scission point: what can we learn from Scission and prompt neutrons? / P. Talou. Fission prompt neutron and gamma multiplicity by statistical decay of fragments / S. Perez-Martin, S. Hilaire, E. Bauge -- Fission theory. Structure and fission properties of actinides with the Gogny force / H. Goutte ... [et al.]. Fission fragment properties from a microscopic approach / N. Dubray, H. Goutte, J.-P. Delaroche. Smoker and non-smoker neutron-induced fission rates / I. Korneev ... [et al.] -- Facilities and detectors. A novel 2v2E spectrometer in Manchester: new development in identification of fission fragments / I. Tsekhanovich ... [et al

  14. The Complete Burning of Weapons Grade Plutonium and Highly Enriched Uranium with (Laser Inertial Fusion-Fission Energy) LIFE Engine

    SciTech Connect

    Farmer, J C; Diaz de la Rubia, T; Moses, E

    2008-12-23

    The National Ignition Facility (NIF) project, a laser-based Inertial Confinement Fusion (ICF) experiment designed to achieve thermonuclear fusion ignition and burn in the laboratory, is under construction at the Lawrence Livermore National Laboratory (LLNL) and will be completed in April of 2009. Experiments designed to accomplish the NIF's goal will commence in late FY2010 utilizing laser energies of 1 to 1.3 MJ. Fusion yields of the order of 10 to 20 MJ are expected soon thereafter. Laser initiated fusion-fission (LIFE) engines have now been designed to produce nuclear power from natural or depleted uranium without isotopic enrichment, and from spent nuclear fuel from light water reactors without chemical separation into weapons-attractive actinide streams. A point-source of high-energy neutrons produced by laser-generated, thermonuclear fusion within a target is used to achieve ultra-deep burn-up of the fertile or fissile fuel in a sub-critical fission blanket. Fertile fuels including depleted uranium (DU), natural uranium (NatU), spent nuclear fuel (SNF), and thorium (Th) can be used. Fissile fuels such as low-enrichment uranium (LEU), excess weapons plutonium (WG-Pu), and excess highly-enriched uranium (HEU) may be used as well. Based upon preliminary analyses, it is believed that LIFE could help meet worldwide electricity needs in a safe and sustainable manner, while drastically shrinking the nation's and world's stockpile of spent nuclear fuel and excess weapons materials. LIFE takes advantage of the significant advances in laser-based inertial confinement fusion that are taking place at the NIF at LLNL where it is expected that thermonuclear ignition will be achieved in the 2010-2011 timeframe. Starting from as little as 300 to 500 MW of fusion power, a single LIFE engine will be able to generate 2000 to 3000 MWt in steady state for periods of years to decades, depending on the nuclear fuel and engine configuration. Because the fission blanket in a fusion-fission

  15. Application of adjusted data in calculating fission-product decay energies and spectra

    NASA Astrophysics Data System (ADS)

    George, D. C.; Labauve, R. J.; England, T. R.

    1982-06-01

    The code ADENA, which approximately calculates fussion-product beta and gamma decay energies and spectra in 19 or fewer energy groups from a mixture of U235 and Pu239 fuels, is described. The calculation uses aggregate, adjusted data derived from a combination of several experiments and summation results based on the ENDF/B-V fission product file. The method used to obtain these adjusted data and the method used by ADENA to calculate fission-product decay energy with an absorption correction are described, and an estimate of the uncertainty of the ADENA results is given. Comparisons of this approximate method are made to experimental measurements, to the ANSI/ANS 5.1-1979 standard, and to other calculational methods. A listing of the complete computer code (ADENA) is contained in an appendix. Included in the listing are data statements containing the adjusted data in the form of parameters to be used in simple analytic functions.

  16. Spontaneous fission

    SciTech Connect

    Hoffman, D.C.

    1993-09-01

    The spontaneous fission (SF) of the heaviest actinides and the transactinides is of particular interest because of the dramatic changes in properties observed in the region of the heavy fermion isotopes and for still heavier elements. The existing experimental information on SF properties including half-life systematics, fragment kinetic-energy and mass-yield distributions, prompt neutron emission, and gamma emission will be reviewed. Possibility for extending studies of SF properties to other regions are considered and the potential for obtaining additional information about low-energy fission properties is discussed.

  17. A physical description of fission product behavior fuels for advanced power reactors.

    SciTech Connect

    Kaganas, G.; Rest, J.; Nuclear Engineering Division; Florida International Univ.

    2007-10-18

    The Global Nuclear Energy Partnership (GNEP) is considering a list of reactors and nuclear fuels as part of its chartered initiative. Because many of the candidate materials have not been explored experimentally under the conditions of interest, and in order to economize on program costs, analytical support in the form of combined first principle and mechanistic modeling is highly desirable. The present work is a compilation of mechanistic models developed in order to describe the fission product behavior of irradiated nuclear fuel. The mechanistic nature of the model development allows for the possibility of describing a range of nuclear fuels under varying operating conditions. Key sources include the FASTGRASS code with an application to UO{sub 2} power reactor fuel and the Dispersion Analysis Research Tool (DART ) with an application to uranium-silicide and uranium-molybdenum research reactor fuel. Described behavior mechanisms are divided into subdivisions treating fundamental materials processes under normal operation as well as the effect of transient heating conditions on these processes. Model topics discussed include intra- and intergranular gas-atom and bubble diffusion, bubble nucleation and growth, gas-atom re-solution, fuel swelling and ?scion gas release. In addition, the effect of an evolving microstructure on these processes (e.g., irradiation-induced recrystallization) is considered. The uranium-alloy fuel, U-xPu-Zr, is investigated and behavior mechanisms are proposed for swelling in the {alpha}-, intermediate- and {gamma}-uranium zones of this fuel. The work reviews the FASTGRASS kinetic/mechanistic description of volatile ?scion products and, separately, the basis for the DART calculation of bubble behavior in amorphous fuels. Development areas and applications for physical nuclear fuel models are identified.

  18. Critical insight into the influence of the potential energy surface on fission dynamics

    SciTech Connect

    Mazurek, K.

    2011-07-15

    The present work is dedicated to a careful investigation of the influence of the potential energy surface on the fission process. The time evolution of nuclei at high excitation energy and angular momentum is studied by means of three-dimensional Langevin calculations performed for two different parametrizations of the macroscopic potential: the Finite Range Liquid Drop Model (FRLDM) and the Lublin-Strasbourg Drop (LSD) prescription. Depending on the mass of the system, the topology of the potential throughout the deformation space of interest in fission is observed to noticeably differ within these two approaches, due to the treatment of curvature effects. When utilized in the dynamical calculation as the driving potential, the FRLDM and LSD models yield similar results in the heavy-mass region, whereas the predictions can be strongly dependent on the Potential Energy Surface (PES) for medium-mass nuclei. In particular, the mass, charge, and total kinetic energy distributions of the fission fragments are found to be narrower with the LSD prescription. The influence of critical model parameters on our findings is carefully investigated. The present study sheds light on the experimental conditions and signatures well suited for constraining the parametrization of the macroscopic potential. Its implication regarding the interpretation of available experimental data is briefly discussed.

  19. 252Cf fission-neutron spectrum using a simplified time-of-flight setup: An advanced teaching laboratory experiment

    NASA Astrophysics Data System (ADS)

    Becchetti, F. D.; Febbraro, M.; Torres-Isea, R.; Ojaruega, M.; Baum, L.

    2013-02-01

    The removal of PuBe and AmBe neutron sources from many university teaching laboratories (due to heightened security issues) has often left a void in teaching various aspects of neutron physics. We have recently replaced such sources with sealed 252Cf oil-well logging sources (nominal 10-100 μCi), and developed several experiments using them as neutron sources. This includes a fission-neutron time-of-flight experiment using plastic scintillators, which utilizes the prompt γ rays emitted in 252Cf spontaneous fission as a fast timing start signal. The experiment can be performed with conventional nuclear instrumentation and a 1-D multi-channel pulse-height analyzer, available in most advanced teaching laboratories. Alternatively, a more sophisticated experiment using liquid scintillators and n/γ pulse-shape discrimination can be performed. Several other experiments using these neutron sources are also feasible. The experiments can introduce students to the problem of detecting the dark matter thought to dominate the universe and to the techniques used to detect contraband fissionable nuclear materials.

  20. Systems Modeling For The Laser Fusion-Fission Energy (LIFE) Power Plant

    SciTech Connect

    Meier, W R; Abbott, R; Beach, R; Blink, J; Caird, J; Erlandson, A; Farmer, J; Halsey, W; Ladran, T; Latkowski, J; MacIntyre, A; Miles, R; Storm, E

    2008-10-02

    A systems model has been developed for the Laser Inertial Fusion-Fission Energy (LIFE) power plant. It combines cost-performance scaling models for the major subsystems of the plant including the laser, inertial fusion target factory, engine (i.e., the chamber including the fission and tritium breeding blankets), energy conversion systems and balance of plant. The LIFE plant model is being used to evaluate design trade-offs and to identify high-leverage R&D. At this point, we are focused more on doing self consistent design trades and optimization as opposed to trying to predict a cost of electricity with a high degree of certainty. Key results show the advantage of large scale (>1000 MWe) plants and the importance of minimizing the cost of diodes and balance of plant cost.

  1. Prompt Fission Gamma-ray Studies at DANCE

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Rusev, G.; Bond, E. M.; Bredeweg, T. A.; Chadwick, M. B.; Couture, A.; Fowler, M. M.; Haight, R. C.; Kawano, T.; Keksis, A. L.; Mosby, S. M.; O'Donnell, J. M.; Rundberg, R. S.; Stetcu, I.; Talou, P.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Stoyer, M. A.; Haslett, R. J.; Henderson, R. A.; Becker, J. A.; Wu, C. Y.

    Measurements of correlated data on prompt-fission γ-rays (PFG) have been carried out for various actinide isotopes in recent years using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL). We have developed a model that conveniently parametrizes the correlated data of γ-ray multiplicity and energy. New results on two- dimensional prompt-fission γ-ray multiplicity versus energy distributions from spontaneous fission on 252Cf and neutron-induced fission on 242mAm are presented together with previously obtained results on 233,235U and 239Pu. Correlated PFG data from 252Cf are also compared to results of the detailed theoretical model developed at LANL, for different thresholds of PFG energies. Future plans to measure correlated data on fission fragments, prompt fission neutrons and γ-rays at DANCE are presented.

  2. Prompt fission gamma-ray studies at DANCE

    SciTech Connect

    Jandel, M.; Rusev, G.; Bond, E. M.; Bredeweg, T. A.; Chadwick, M. B.; Couture, A.; Fowler, M.. M; Haight, R. C.; Kawano, T.; Keksis, A. L.; Mosby, S. M.; O’Donnell, J. M.; Rundberg, R. S.; Stetcu, I.; Talou, P.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Stoyer, M. A.; Haslett, R. J.; Henderson, R. A.; Becker, J. A.; Wu, C. Y.

    2014-11-26

    Measurements of correlated data on prompt-fission γ-rays (PFG) have been carried out for various actinide isotopes in recent years using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL). We have developed a model that conveniently parametrizes the correlated data of γ-ray multiplicity and energy. New results on two- dimensional prompt-fission γ-ray multiplicity versus energy distributions from spontaneous fission on ²⁵²Cf and neutron-induced fission on 242mAm are presented together with previously obtained results on 233,235U and ²³⁹Pu. Correlated PFG data from ²⁵²Cf are also compared to results of the detailed theoretical model developed at LANL, for different thresholds of PFG energies. Future plans to measure correlated data on fission fragments, prompt fission neutrons and γ-rays at DANCE are presented.

  3. Statistical and evaporation models for the neutron emission energy spectrum in the center-of-mass system from fission fragments

    NASA Astrophysics Data System (ADS)

    Kawano, T.; Talou, P.; Stetcu, I.; Chadwick, M. B.

    2013-09-01

    The neutron emission energy spectra in the CMS (center-of-mass) frame from two compound nuclei produced by fission are studied. The neutron spectra calculated with the Hauser-Feshbach statistical model are compared with the evaporation theory, and the definition of the temperature is revisited. Using the Monte Carlo technique we average the CMS neutron spectra from many fission fragments to construct the representative CMS spectrum from both the light and heavy fragments. The CMS spectra for each fission fragment pair are also converted into the laboratory frame to calculate the total prompt fission neutron spectrum that can be observed experimentally. This is compared to measured laboratory data for thermal neutron induced fission on 235U. We show that the Hauser-Feshbach calculation gives a different spectrum shape than the Madland-Nix model calculation.

  4. Total fission cross section of {sup 181}Ta and {sup 208}Pb induced by protons at relativistic energies

    SciTech Connect

    Ayyad, Y.; Benlliure, J.; Casarejos, E.; Schmidt, K. H.; Jurado, B.; Pol, H. A.; Ricciardi, M. V.; Pleskac, R.; Enqvist, T.; Rejmund, F.; Giot, L.; Henzl, V.; Lukic, S.; Ngoc, S. N.; Boudard, A.; Leray, S.; Kurtukian, T.; Schmitt, C.; Henzlova, D.; Paradela, C.; Bacquias, A.; Loureiro, D. P.; Foehr, V.; Tarrio, D.; Kezzar, K.

    2011-07-01

    Total fission cross section induced by protons in {sup 181}Ta and {sup 208}Pb at energies in the range of 300 to 1000 A MeV have been measured at GSI (Germany) using the inverse kinematics technique. A dedicated setup with high efficiency made it possible to determine these cross sections with high accuracy. The new data seed light in the controversial results obtained so far and contribute to the understanding of the fission process at high excitation energies. (authors)

  5. Fission fragment mass and energy distributions as a function of incident neutron energy measured in a lead slowing-down spectrometer

    SciTech Connect

    Romano, C.; Danon, Y.; Block, R.; Thompson, J.; Blain, E.; Bond, E.

    2010-01-15

    A new method of measuring fission fragment mass and energy distributions as a function of incident neutron energy in the range from below 0.1 eV to 1 keV has been developed. The method involves placing a double-sided Frisch-gridded fission chamber in Rensselaer Polytechnic Institute's lead slowing-down spectrometer (LSDS). The high neutron flux of the LSDS allows for the measurement of the energy-dependent, neutron-induced fission cross sections simultaneously with the mass and kinetic energy of the fission fragments of various small samples. The samples may be isotopes that are not available in large quantities (submicrograms) or with small fission cross sections (microbarns). The fission chamber consists of two anodes shielded by Frisch grids on either side of a single cathode. The sample is located in the center of the cathode and is made by depositing small amounts of actinides on very thin films. The chamber was successfully tested and calibrated using 0.41+-0.04 ng of {sup 252}Cf and the resulting mass distributions were compared to those of previous work. As a proof of concept, the chamber was placed in the LSDS to measure the neutron-induced fission cross section and fragment mass and energy distributions of 25.3+-0.5 mug of {sup 235}U. Changes in the mass distributions as a function of incident neutron energy are evident and are examined using the multimodal fission mode model.

  6. Bimodal fission

    SciTech Connect

    Hulet, E.K.

    1989-04-19

    In recent years, we have measured the mass and kinetic-energy distributions from the spontaneous fission of /sup 258/Fm, /sup 259/Md, /sup 260/Md, /sup 258/No, /sup 262/No, and /sup 260/(104). All are observed to fission with a symmetrical division of mass, whereas the total-kinetic-energy (TKE) distributions strongly deviated from the Gaussian shape characteristically found in the fission of all other actinides. When the TKE distributions are resolved into two Gaussians the constituent peaks lie near 200 and near 233 MeV. We conclude two modes or bimodal fission is occurring in five of the six nuclides studied. Both modes are possible in the same nuclides, but one generally predominates. We also conclude the low-energy but mass-symmetrical mode is likely to extend to far heavier nuclei; while the high-energy mode will be restricted to a smaller region, a region of nuclei defined by the proximity of the fragments to the strong neutron and proton shells in /sup 132/Sn. 16 refs., 7 figs., 1 tab.

  7. Mass-energy distribution of fragments within Langevin dynamics of fission induced by heavy ions

    SciTech Connect

    Anischenko, Yu. A. Adeev, G. D.

    2012-08-15

    A stochastic approach based on four-dimensional Langevin fission dynamics is applied to calculating mass-energy distributions of fragments originating from the fission of excited compound nuclei. In the model under investigation, the coordinate K representing the projection of the total angular momentum onto the symmetry axis of the nucleus is taken into account in addition to three collective shape coordinates introduced on the basis of the {l_brace}c, h, {alpha}{r_brace} parametrization. The evolution of the orientation degree of freedom (K mode) is described by means of the Langevin equation in the overdamped regime. The tensor of friction is calculated under the assumption of the reducedmechanismof one-body dissipation in the wall-plus-window model. The calculations are performed for two values of the coefficient that takes into account the reduction of the contribution from the wall formula: k{sub s} 0.25 and k{sub s} = 1.0. Calculations with a modified wall-plus-window formula are also performed, and the quantity measuring the degree to which the single-particle motion of nucleons within the nuclear system being considered is chaotic is used for k{sub s} in this calculation. Fusion-fission reactions leading to the production of compound nuclei are considered for values of the parameter Z{sup 2}/A in the range between 21 and 44. So wide a range is chosen in order to perform a comparative analysis not only for heavy but also for light compound nuclei in the vicinity of the Businaro-Gallone point. For all of the reactions considered in the present study, the calculations performed within four-dimensional Langevin dynamics faithfully reproduce mass-energy and mass distributions obtained experimentally. The inclusion of the K mode in the Langevin equation leads to an increase in the variances of mass and energy distributions in relation to what one obtains from three-dimensional Langevin calculations. The results of the calculations where one associates k{sub s

  8. Installation and Final Testing of an On-Line, Multi-Spectrometer Fission Product Monitoring System (FPMS) to Support Advanced Gas Reactor (AGR) Fuel Testing and Qualification in the Advanced Test Reactor

    SciTech Connect

    J. K. Hartwell; D. M. Scates; M. W. Drigert; J. B. Walter

    2006-10-01

    The US Department of Energy (DOE) is initiating tests of reactor fuel for use in an Advanced Gas Reactor (AGR). The AGR will use helium coolant, a low-power-density ceramic core, and coated-particle fuel. A series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). One important measure of fuel performance in these tests is quantification of the fission gas releases over the nominal 2-year duration of each irradiation experiment. This test objective will be met using the AGR Fission Product Monitoring System (FPMS) which includes seven (7) on-line detection stations viewing each of the six test capsule effluent lines (plus one spare). Each station incorporates both a heavily-shielded high-purity germanium (HPGe) gamma-ray spectrometer for quantification of the isotopic releases, and a NaI(Tl) scintillation detector to monitor the total count rate and identify the timing of the releases. The AGR-1 experiment will begin irradiation after October 1, 2006. To support this experiment, the FPMS has been completely assembled, tested, and calibrated in a laboratory at the INL, and then reassembled and tested in its final location in the ATR reactor basement. This paper presents the details of the equipment performance, the control and acquisition software, the test plan for the irradiation monitoring, and the installation in the ATR basement. Preliminary on-line data may be available by the Conference date.

  9. DESIGN OF AN ON-LINE, MULTI-SPECTROMETER FISSION PRODUCT MONITORING SYSTEM (FPMS) TO SUPPORT ADVANCED GAS REACTOR (AGR) FUEL TESTING AND QUALIFICATION IN THE ADVANCED TEST REACTOR

    SciTech Connect

    J. K. Hartwell; D. M. Scates; M. W. Drigert

    2005-11-01

    The US Department of Energy (DOE) is embarking on a series of tests of coated-particle reactor fuel for the Advanced Gas Reactor (AGR). As one part of this fuel development program a series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). The first test in this series (AGR-1) will incorporate six separate “capsules” irradiated simultaneously, each containing about 51,000 TRISO-coated fuel particles supported in a graphite matrix and continuously swept with inert gas during irradiation. The effluent gas from each of the six capsules must be independently monitored in near real time and the activity of various fission gas nuclides determined and reported. A set of seven heavily-shielded high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based total radiation detectors have been designed, and are being configured and tested for use during the AGR-1 experiment. The AGR-1 test specification requires that the AGR-1 fission product measurement system (FPMS) have sufficient sensitivity to detect the failure of a single coated fuel particle and sufficient range to allow it to “count” multiple (up to 250) successive particle failures. This paper describes the design and expected performance of the AGR-1 FPMS.

  10. Fission Systems for Mars Exploration

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Kim, T.; Dorney, D. J.; Swint, Marion Shayne

    2012-01-01

    Fission systems are used extensively on earth, and 34 such systems have flown in space. The energy density of fission is over 10 million times that of chemical reactions, giving fission the potential to eliminate energy density constraints for many space missions. Potential safety and operational concerns with fission systems are well understood, and strategies exist for affordably developing such systems. By enabling a power-rich environment and highly efficient propulsion, fission systems could enable affordable, sustainable exploration of Mars.

  11. Energy Storage (II): Developing Advanced Technologies

    ERIC Educational Resources Information Center

    Robinson, Arthur L

    1974-01-01

    Energy storage, considered by some scientists to be the best technological and economic advancement after advanced nuclear power, still rates only modest funding for research concerning the development of advanced technologies. (PEB)

  12. Linear Free Energy Correlations for Fission Product Release from the Fukushima-Daiichi Nuclear Accident

    SciTech Connect

    Abrecht, David G.; Schwantes, Jon M.

    2015-03-03

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes, et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the source of the radionuclides to be from active reactors rather than the spent fuel pool. Linear correlations of the form ln χ = -α (ΔGrxn°(TC))/(RTC)+β were obtained between the deposited concentration and the reduction potential of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn(TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2130 K and 2220 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, 151Sm through atmospheric venting and releases during the first month following the accident were performed, and indicate large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores.

  13. Linear free energy correlations for fission product release from the Fukushima-Daiichi nuclear accident.

    PubMed

    Abrecht, David G; Schwantes, Jon M

    2015-03-01

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the initial source of the radionuclides to the environment to be from active reactors rather than the spent fuel pool. Linear correlations of the form In χ = −α ((ΔGrxn°(TC))/(RTC)) + β were obtained between the deposited concentrations, and the reduction potentials of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn (TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2015 and 2060 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, and 151Sm through atmospheric venting during the first month following the accident were obtained, indicating that large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores.

  14. Low-Energy Fusion-Fission Dynamics of Heavy Nuclear Systems

    SciTech Connect

    Zagrebaev, Valery; Greiner, Walter

    2006-08-14

    A new approach is proposed for a unified description of strongly coupled deep-inelastic (DI) scattering, fusion, fission, and quasi-fission (QF) processes of heavy ion collisions. A unified driving-potential and a unified set of dynamic Langevin-type equations of motion are used in this approach. This makes it possible to perform a full (continuous) time analysis of the evolution of heavy nuclear systems, starting from the approaching stage, moving up to the formation of the compound nucleus or emerging into two final fragments. The calculated mass, charge, energy and angular distributions of the reaction products agree well with the corresponding experimental data for heavy and superheavy nuclear systems. Collisions of very heavy nuclei (such as 238U+248Cm) are investigated as an alternative way for production of superheavy elements. Large charge and mass transfer was found in these reactions due to the inverse (anti-symmetrizing) quasi-fission process leading to formation of surviving superheavy long-lived neutron-rich nuclei.

  15. Linear free energy correlations for fission product release from the Fukushima-Daiichi nuclear accident.

    PubMed

    Abrecht, David G; Schwantes, Jon M

    2015-03-01

    This paper extends the preliminary linear free energy correlations for radionuclide release performed by Schwantes et al., following the Fukushima-Daiichi Nuclear Power Plant accident. Through evaluations of the molar fractionations of radionuclides deposited in the soil relative to modeled radionuclide inventories, we confirm the initial source of the radionuclides to the environment to be from active reactors rather than the spent fuel pool. Linear correlations of the form In χ = −α ((ΔGrxn°(TC))/(RTC)) + β were obtained between the deposited concentrations, and the reduction potentials of the fission product oxide species using multiple reduction schemes to calculate ΔG°rxn (TC). These models allowed an estimate of the upper bound for the reactor temperatures of TC between 2015 and 2060 K, providing insight into the limiting factors to vaporization and release of fission products during the reactor accident. Estimates of the release of medium-lived fission products 90Sr, 121mSn, 147Pm, 144Ce, 152Eu, 154Eu, 155Eu, and 151Sm through atmospheric venting during the first month following the accident were obtained, indicating that large quantities of 90Sr and radioactive lanthanides were likely to remain in the damaged reactor cores. PMID:25675358

  16. Fission Spectrum

    DOE R&D Accomplishments Database

    Bloch, F.; Staub, H.

    1943-08-18

    Measurements of the spectrum of the fission neutrons of 25 are described, in which the energy of the neutrons is determined from the ionization produced by individual hydrogen recoils. The slow neutrons producing fission are obtained by slowing down the fast neutrons from the Be-D reaction of the Stanford cyclotron. In order to distinguish between fission neutrons and the remaining fast cyclotron neutrons both the cyclotron current and the pusle amplifier are modulated. A hollow neutron container, in which slow neutrons have a lifetime of about 2 milliseconds, avoids the use of large distances. This method results in much higher intensities than the usual modulation arrangement. The results show a continuous distribution of neutrons with a rather wide maximum at about 0.8 MV falling off to half of its maximum value at 2.0 MV. The total number of netrons is determined by comparison with the number of fission fragments. The result seems to indicate that only about 30% of the neutrons have energies below .8 MV. Various tests are described which were performed in order to rule out modification of the spectrum by inelastic scattering. Decl. May 4, 1951

  17. Mass Yields and Average Total Kinetic Energy Release in Fission for 235U, 238U, and 239Pu

    NASA Astrophysics Data System (ADS)

    Duke, Dana

    2015-10-01

    Mass yield distributions and average total kinetic energy (TKE) in neutron induced fission of 235U, 238U, and 239Pu targets were measured with a gridded ionization chamber. Despite decades of fission research, our understanding of how fragment mass yields and TKE depend on incident neutron energy is limited, especially at higher energies (above 5-10 MeV). Improved accuracy in these quantities is important for nuclear technology as it enhances our simulation capabilities and increases the confidence in diagnostic tools. The data can also guide and validate theoretical fission models where the correlation between the fragment mass and TKE is of particular value for constraining models. The Los Alamos Neutron Science Center - Weapons Neutron Research (LANSCE - WNR) provides a neutron beam with energies from thermal to hundreds of MeV, well-suited for filling in the gaps in existing data and exploring fission behavior in the fast neutron region. The results of the studies on target nuclei 235U, 238U, and 239Pu will be presented with a focus on exploring data trends as a function of neutron energy from thermal through 30 MeV. Results indicate clear evidence of structure due to multi-chance fission in the TKE . LA-UR-15-24761.

  18. Utilizing Fission Technology to Enable Rapid and Affordable Access to any Point in the Solar System

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Bonometti, Joe; Morton, Jeff; Hrbud, Ivana; Bitteker, Leo; VanDyke, Melissa; Godfroy, T.; Pedersen, K.; Dobson, C.; Patton, B.; Martin, J.; Chakrabarti, S.

    2000-01-01

    Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include bimodal nuclear thermal rockets, high specific energy propulsion systems, and pulsed fission propulsion systems. In-space propellant re-supply enhances the effective performance of all systems, but requires significant infrastructure development. Safe, timely, affordable utilization of first-generation space fission propulsion systems will enable the development of more advanced systems. First generation systems can build on over 45 years of US and international space fission system technology development to minimize cost.

  19. Fluctuations in Electronic Energy Affecting Singlet Fission Dynamics and Mixing with Charge-Transfer State: Quantum Dynamics Study.

    PubMed

    Fujihashi, Yuta; Ishizaki, Akihito

    2016-02-01

    Singlet fission is a spin-allowed process by which a singlet excited state is converted to two triplet states. To understand mechanisms of the ultrafast fission via a charge transfer (CT) state, one has investigated the dynamics through quantum-dynamical calculations with the uncorrelated fluctuation model; however, the electronic states are expected to experience the same fluctuations induced by the surrounding molecules because the electronic structure of the triplet pair state is similar to that of the singlet state except for the spin configuration. Therefore, the fluctuations in the electronic energies could be correlated, and the 1D reaction coordinate model may adequately describe the fission dynamics. In this work we develop a model for describing the fission dynamics to explain the experimentally observed behaviors. We also explore impacts of fluctuations in the energy of the CT state on the fission dynamics and the mixing with the CT state. The overall behavior of the dynamics is insensitive to values of the reorganization energy associated with the transition from the singlet state to the CT state, although the coherent oscillation is affected by the fluctuations. This result indicates that the mixing with the CT state is rather robust under the fluctuations in the energy of the CT state as well as the high-lying CT state. PMID:26732701

  20. Comparative evaluation of solar, fission, fusion, and fossil energy resources, part 3

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Reupke, W. A.

    1974-01-01

    The role of nuclear fission reactors in becoming an important power source in the world is discussed. The supply of fissile nuclear fuel will be severely depleted by the year 2000. With breeder reactors the world supply of uranium could last thousands of years. However, breeder reactors have problems of a large radioactive inventory and an accident potential which could present an unacceptable hazard. Although breeder reactors afford a possible solution to the energy shortage, their ultimate role will depend on demonstrated safety and acceptable risks and environmental effects. Fusion power would also be a long range, essentially permanent, solution to the world's energy problem. Fusion appears to compare favorably with breeders in safety and environmental effects. Research comparing a controlled fusion reactor with the breeder reactor in solving our long range energy needs is discussed.

  1. Cherenkov light detection as a velocity selector for uranium fission products at intermediate energies

    NASA Astrophysics Data System (ADS)

    Yamaguchi, T.; Enomoto, A.; Kouno, J.; Yamaki, S.; Matsunaga, S.; Suzaki, F.; Suzuki, T.; Abe, Y.; Nagae, D.; Okada, S.; Ozawa, A.; Saito, Y.; Sawahata, K.; Kitagawa, A.; Sato, S.

    2014-12-01

    The in-flight particle separation capability of intermediate-energy radioactive ion (RI) beams produced at a fragment separator can be improved with the Cherenkov light detection technique. The cone angle of Cherenkov light emission varies as a function of beam velocity. This can be exploited as a velocity selector for secondary beams. Using heavy ion beams available at the HIMAC synchrotron facility, the Cherenkov light angular distribution was measured for several thin radiators with high refractive indices (n = 1.9 ~ 2.1). A velocity resolution of ~10-3 was achieved for a 56Fe beam with an energy of 500 MeV/nucleon. Combined with the conventional rigidity selection technique coupled with energy-loss analysis, the present method will enable the efficient selection of an exotic species from huge amounts of various nuclides, such as uranium fission products at the BigRIPS fragment separator located at the RI Beam Factory.

  2. New antineutrino energy spectra predictions from the summation of beta decay branches of the fission products.

    PubMed

    Fallot, M; Cormon, S; Estienne, M; Algora, A; Bui, V M; Cucoanes, A; Elnimr, M; Giot, L; Jordan, D; Martino, J; Onillon, A; Porta, A; Pronost, G; Remoto, A; Taín, J L; Yermia, F; Zakari-Issoufou, A-A

    2012-11-16

    In this Letter, we study the impact of the inclusion of the recently measured beta decay properties of the (102;104;105;106;107)Tc, (105)Mo, and (101)Nb nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes (235,238)U and (239,241)Pu. These actinides are the main contributors to the fission processes in pressurized water reactors. The beta feeding probabilities of the above-mentioned Tc, Mo, and Nb isotopes have been found to play a major role in the γ component of the decay heat of (239)Pu, solving a large part of the γ discrepancy in the 4-3000 s range. They have been measured by using the total absorption technique, insensitive to the pandemonium effect. The calculations are performed by using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of (235)U, (239,241)Pu, and, in particular, (238)U for which no measurement has been published yet. We conclude that new total absorption technique measurements are mandatory to improve the reliability of the predicted spectra. PMID:23215477

  3. New Antineutrino Energy Spectra Predictions from the Summation of Beta Decay Branches of the Fission Products

    NASA Astrophysics Data System (ADS)

    Fallot, M.; Cormon, S.; Estienne, M.; Algora, A.; Bui, V. M.; Cucoanes, A.; Elnimr, M.; Giot, L.; Jordan, D.; Martino, J.; Onillon, A.; Porta, A.; Pronost, G.; Remoto, A.; Taín, J. L.; Yermia, F.; Zakari-Issoufou, A.-A.

    2012-11-01

    In this Letter, we study the impact of the inclusion of the recently measured beta decay properties of the Tc102;104;105;106;107, Mo105, and Nb101 nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes U235,238 and Pu239,241. These actinides are the main contributors to the fission processes in pressurized water reactors. The beta feeding probabilities of the above-mentioned Tc, Mo, and Nb isotopes have been found to play a major role in the γ component of the decay heat of Pu239, solving a large part of the γ discrepancy in the 4-3000 s range. They have been measured by using the total absorption technique, insensitive to the pandemonium effect. The calculations are performed by using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of U235, Pu239,241, and, in particular, U238 for which no measurement has been published yet. We conclude that new total absorption technique measurements are mandatory to improve the reliability of the predicted spectra.

  4. New antineutrino energy spectra predictions from the summation of beta decay branches of the fission products.

    PubMed

    Fallot, M; Cormon, S; Estienne, M; Algora, A; Bui, V M; Cucoanes, A; Elnimr, M; Giot, L; Jordan, D; Martino, J; Onillon, A; Porta, A; Pronost, G; Remoto, A; Taín, J L; Yermia, F; Zakari-Issoufou, A-A

    2012-11-16

    In this Letter, we study the impact of the inclusion of the recently measured beta decay properties of the (102;104;105;106;107)Tc, (105)Mo, and (101)Nb nuclei in an updated calculation of the antineutrino energy spectra of the four fissible isotopes (235,238)U and (239,241)Pu. These actinides are the main contributors to the fission processes in pressurized water reactors. The beta feeding probabilities of the above-mentioned Tc, Mo, and Nb isotopes have been found to play a major role in the γ component of the decay heat of (239)Pu, solving a large part of the γ discrepancy in the 4-3000 s range. They have been measured by using the total absorption technique, insensitive to the pandemonium effect. The calculations are performed by using the information available nowadays in the nuclear databases, summing all the contributions of the beta decay branches of the fission products. Our results provide a new prediction of the antineutrino energy spectra of (235)U, (239,241)Pu, and, in particular, (238)U for which no measurement has been published yet. We conclude that new total absorption technique measurements are mandatory to improve the reliability of the predicted spectra.

  5. Fission fragment charge and mass distributions in 239Pu(n ,f ) in the adiabatic nuclear energy density functional theory

    NASA Astrophysics Data System (ADS)

    Regnier, D.; Dubray, N.; Schunck, N.; Verrière, M.

    2016-05-01

    Background: Accurate knowledge of fission fragment yields is an essential ingredient of numerous applications ranging from the formation of elements in the r process to fuel cycle optimization for nuclear energy. The need for a predictive theory applicable where no data are available, together with the variety of potential applications, is an incentive to develop a fully microscopic approach to fission dynamics. Purpose: In this work, we calculate the pre-neutron emission charge and mass distributions of the fission fragments formed in the neutron-induced fission of 239Pu using a microscopic method based on nuclear density functional theory (DFT). Methods: Our theoretical framework is the nuclear energy density functional (EDF) method, where large-amplitude collective motion is treated adiabatically by using the time-dependent generator coordinate method (TDGCM) under the Gaussian overlap approximation (GOA). In practice, the TDGCM is implemented in two steps. First, a series of constrained EDF calculations map the configuration and potential-energy landscape of the fissioning system for a small set of collective variables (in this work, the axial quadrupole and octupole moments of the nucleus). Then, nuclear dynamics is modeled by propagating a collective wave packet on the potential-energy surface. Fission fragment distributions are extracted from the flux of the collective wave packet through the scission line. Results: We find that the main characteristics of the fission charge and mass distributions can be well reproduced by existing energy functionals even in two-dimensional collective spaces. Theory and experiment agree typically within two mass units for the position of the asymmetric peak. As expected, calculations are sensitive to the structure of the initial state and the prescription for the collective inertia. We emphasize that results are also sensitive to the continuity of the collective landscape near scission. Conclusions: Our analysis confirms

  6. Systematics of the mean energy and the mean multiplicity of prompt neutrons originating from {sup 232}Th fission

    SciTech Connect

    Svirin, M. I.

    2012-12-15

    The cross section for the neutron-induced fission of {sup 232}Th target nuclei, {sigma}{sub f} (E{sub n}), was described within statistical theory. The spectra of the mean multiplicity, v-bar (E{sub n}), and the mean energy, E-bar(E{sub n}), of secondary neutrons accompanying {sup 232}Th fission induced by neutrons of energy extending up to E{sub n} = 20 MeV were analyzed on the basis of the chance structure of the cross section.

  7. Advanced shield development for a fission surface power system for the lunar surface

    SciTech Connect

    A. E. Craft; I. J. Silver; C. M. Clark; S. D. Howe; J. C. King

    2011-02-01

    A nuclear reactor power system such as the affordable fission surface power system enables a potential outpostonthemoon.Aradiation shieldmustbe included in the reactor system to reduce the otherwise excessive dose to the astronauts and other vital system components. The radiation shield is typically the most massive component of a space reactor system, and thus must be optimized to reduce mass asmuchas possible while still providing the required protection.Various shield options for an on-lander reactor system are examined for outpost distances of 400m and 1 kmfromthe reactor. Also investigated is the resulting mass savings from the use of a high performance cermet fuel. A thermal analysis is performed to determine the thermal behaviours of radiation shields using borated water. For an outpost located 1000m from the core, a tetramethylammonium borohydride shield is the lightest (5148.4 kg), followed by a trilayer shield (boron carbide–tungsten–borated water; 5832.3 kg), and finally a borated water shield (6020.7 kg). In all of the final design cases, the temperature of the borated water remains below 400 K.

  8. Dynamical interpretation of average fission-fragment kinetic energy systematics and nuclear scission

    SciTech Connect

    Nadtochy, P.N.; Adeev, G.D.

    2005-11-01

    A dynamical interpretation of the well-known systematics for average total kinetic energy of fission fragments over a wide range of the Coulomb parameter (600fission theory--at zero neck radius and at finite neck radius--have been applied in dynamical calculations. Both have resulted in a fairly good description of the dependence of on the Coulomb parameter. The results of dynamical calculations of within three-dimensional Langevin dynamics show that the mean distance between the centers of mass of nascent fragments at the scission configuration increases linearly with the parameter Z{sup 2}/A{sup 1/3}. This distance changes approximately from 2.35R{sub 0} for {sup 119}Xe to 2.6R{sub 0} for {sup 256}Fm. In spite of this increase in mean distance between future fragments at scission, the linear dependence of on the parameter Z{sup 2}/A{sup 1/3} remains approximately valid over a wide range of the Coulomb parameter Z{sup 2}/A{sup 1/3}.

  9. Coincident measurements of prompt fission γ rays and fission fragments at DANCE

    NASA Astrophysics Data System (ADS)

    Walker, C. L.; Baramsai, B.; Jandel, M.; Rusev, G.; Couture, A.; Mosby, S.; Ullmann, J.; Kawano, T.; Stetcu, I.; Talou, P.

    2015-10-01

    Modern statistical approaches to modeling fission involve the calculation of not only average quantities but also fully correlated distributions of all fission products. Applications such as those involving the detection of special nuclear materials also rely on fully correlated data of fission products. Experimental measurements of correlated data are thus critical to the validation of theory and the development of important applications. The goal of this experiment was to measure properties of prompt fission gamma-ray emission as a function of fission fragments' total kinetic energy in the spontaneous fission of 252Cf. The measurement was carried out at the Detector for Advanced Neutron Capture Experiments (DANCE), a 4 π γ-ray calorimeter. A prototype design consisting of two silicon detectors was installed in the center of DANCE, allowing simultaneous measurement of fission fragments and γ rays. Effort has been taken to simulate fragment kinetic energy losses as well as γ-ray attenuation in DANCE using such tools as GEANT4 and SRIM. Theoretical predictions generated by the code CGMF were also incorporated as input for these simulations. Results from the experiment and simulations will be presented, along with plans for future measurements.

  10. Compact fission counter for DANCE

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D; Bredeweg, T; Couture, A; Jandel, M; Ullmann, J

    2010-11-06

    The Detector for Advanced Neutron Capture Experiments (DANCE) consists of 160 BF{sub 2} crystals with equal solid-angle coverage. DANCE is a 4{pi} {gamma}-ray calorimeter and designed to study the neutron-capture reactions on small quantities of radioactive and rare stable nuclei. These reactions are important for the radiochemistry applications and modeling the element production in stars. The recognition of capture event is made by the summed {gamma}-ray energy which is equivalent of the reaction Q-value and unique for a given capture reaction. For a selective group of actinides, where the neutron-induced fission reaction competes favorably with the neutron capture reaction, additional signature is needed to distinguish between fission and capture {gamma} rays for the DANCE measurement. This can be accomplished by introducing a detector system to tag fission fragments and thus establish a unique signature for the fission event. Once this system is implemented, one has the opportunity to study not only the capture but also fission reactions. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to {alpha} particles, which is important for experiments with {alpha}-emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. A PPAC with an ingenious design was fabricated in 2006 by integrating amplifiers into the target assembly. However, this counter was proved to be unsuitable for this application because of issues related to the stability of amplifiers and the ability to separate fission fragments from {alpha}'s. Therefore, a new design is needed. A LLNL proposal to develop a new PPAC for DANCE was funded by NA22 in FY09. The design goal is to minimize the mass for the proposed counter

  11. Singlet exciton fission for solar cell applications: energy aspects of interchromophore coupling.

    PubMed

    Greyson, Eric C; Stepp, Brian R; Chen, Xudong; Schwerin, Andrew F; Paci, Irina; Smith, Millicent B; Akdag, Akin; Johnson, Justin C; Nozik, Arthur J; Michl, Josef; Ratner, Mark A

    2010-11-18

    Singlet exciton fission, a process that converts one singlet exciton to a pair of triplet excitons, has the potential to enhance the efficiency of both bulk heterojunction and dye-sensitized solar cells and is understood in crystals but not well understood in molecules. Previous studies have identified promising building blocks for singlet fission in molecular systems, but little work has investigated how these individual chromophores should be combined to maximize triplet yield. We consider the effects of chemically connecting two chromophores to create a coupled chromophore pair and compute how various structural choices alter the thermodynamic and kinetic parameters likely to control singlet fission yield. We use density functional theory to compute the electron transfer matrix element and the thermodynamics of fission for several promising chromophore pairs and find a trade-off between the desire to maximize this element and the desire to keep the singlet fission process exoergic. We identify promising molecular systems for singlet fission and suggest future experiments.

  12. Brownian shape motion on five-dimensional potential-energy surfaces:nuclear fission-fragment mass distributions.

    PubMed

    Randrup, Jørgen; Möller, Peter

    2011-04-01

    Although nuclear fission can be understood qualitatively as an evolution of the nuclear shape, a quantitative description has proven to be very elusive. In particular, until now, there existed no model with demonstrated predictive power for the fission-fragment mass yields. Exploiting the expected strongly damped character of nuclear dynamics, we treat the nuclear shape evolution in analogy with Brownian motion and perform random walks on five-dimensional fission potential-energy surfaces which were calculated previously and are the most comprehensive available. Test applications give good reproduction of highly variable experimental mass yields. This novel general approach requires only a single new global parameter, namely, the critical neck size at which the mass split is frozen in, and the results are remarkably insensitive to its specific value.

  13. Brownian Shape Motion on Five-Dimensional Potential-Energy Surfaces:Nuclear Fission-Fragment Mass Distributions

    SciTech Connect

    Randrup, Joergen; Moeller, Peter

    2011-04-01

    Although nuclear fission can be understood qualitatively as an evolution of the nuclear shape, a quantitative description has proven to be very elusive. In particular, until now, there existed no model with demonstrated predictive power for the fission-fragment mass yields. Exploiting the expected strongly damped character of nuclear dynamics, we treat the nuclear shape evolution in analogy with Brownian motion and perform random walks on five-dimensional fission potential-energy surfaces which were calculated previously and are the most comprehensive available. Test applications give good reproduction of highly variable experimental mass yields. This novel general approach requires only a single new global parameter, namely, the critical neck size at which the mass split is frozen in, and the results are remarkably insensitive to its specific value.

  14. Basic results of investigations of scission neutrons in nuclear fission at low excitation energies

    SciTech Connect

    Petrov, G. A. Gagarski, A. M.; Guseva, I. S.; Sokolov, V. E.; Val'ski, G. V.; Vorobiev, A. S.; Krinitcin, D. O.; Shcherbakov, O. A.; Nikolaev, D. V.; Pleva, Yu. S.; Petrova, V. I.; Zavarukhina, T. A.

    2008-07-15

    To estimate the main characteristics of neutrons emitted shortly before the scission of a fissioning nucleus, various experiments sensitive to the presence of these scission neutrons in thermal-neutron-induced fission of {sup 235}U and spontaneous fission of {sup 252}Cf were performed. The results of the experiments were analyzed within theoretical calculations allowing for various possible neutron-emission mechanisms, including the possibility of the emergence of neutrons from the scission of a nucleus.

  15. Fission of /sup 255,256/Es, /sup 255en-dash257/Fm, and /sup 258/Md at moderate excitation energies

    SciTech Connect

    Britt, H.C.; Hoffman, D.C.; van der Plicht, J.; Wilhelmy, J.B.; Cheifetz, E.; Dupzyk, R.J.; Lougheed, R.W.

    1984-08-01

    The fission of /sup 255,256/Es, /sup 255en-dash257/Fm, and /sup 258/Md has been studied in the excitation energy range from threshold to 25 MeV. A target of /sup 254/Es was used in the direct reaction studies; (d,pf), (t,pf), (/sup 3/He,df), (/sup 3/He,pf), and in the compound induced fission reactions formed with p, d, t, and ..cap alpha.. particle projectiles. Coincident fission fragment energies were recorded along with (in the direct reaction studies) the outgoing light charged particle. The mass and kinetic energy distributions were studied as a function of nuclear excitation energy. The observed bulk properties were consistent with established systematics in that they exhibited an asymmetric mass distribution and a phenomenologically consistent total kinetic energy. However, the systems demonstrated a fission decay mode which we ascribe to high energy symmetric fission decay. This component, though somewhat arbitrary in its definition, showed a general decrease in yield as a function of increasing nuclear excitation energy. This observed rapid change in fission properties between ''normal'' and high energy symmetric fission probably points to the important observable consequences that can occur from small variations in the potential energy surface.

  16. Microstructural Characterization of a Mg Matrix U-Mo Dispersion Fuel Plate Irradiated in the Advanced Test Reactor to High Fission Density: SEM Results

    NASA Astrophysics Data System (ADS)

    Keiser, Dennis D.; Jue, Jan-Fong; Miller, Brandon D.; Gan, Jian; Robinson, Adam B.; Medvedev, Pavel G.; Madden, James W.; Moore, Glenn A.

    2016-06-01

    Low-enriched (U-235 <20 pct) U-Mo dispersion fuel is being developed for use in research and test reactors. In most cases, fuel plates with Al or Al-Si alloy matrices have been tested in the Advanced Test Reactor to support this development. In addition, fuel plates with Mg as the matrix have also been tested. The benefit of using Mg as the matrix is that it potentially will not chemically interact with the U-Mo fuel particles during fabrication or irradiation, whereas with Al and Al-Si alloys such interactions will occur. Fuel plate R9R010 is a Mg matrix fuel plate that was aggressively irradiated in ATR. This fuel plate was irradiated as part of the RERTR-8 experiment at high temperature, high fission rate, and high power, up to high fission density. This paper describes the results of the scanning electron microscopy (SEM) analysis of an irradiated fuel plate using polished samples and those produced with a focused ion beam. A follow-up paper will discuss the results of transmission electron microscopy (TEM) analysis. Using SEM, it was observed that even at very aggressive irradiation conditions, negligible chemical interaction occurred between the irradiated U-7Mo fuel particles and Mg matrix; no interconnection of fission gas bubbles from fuel particle to fuel particle was observed; the interconnected fission gas bubbles that were observed in the irradiated U-7Mo particles resulted in some transport of solid fission products to the U-7Mo/Mg interface; the presence of microstructural pathways in some U-9.1 Mo particles that could allow for transport of fission gases did not result in the apparent presence of large porosity at the U-7Mo/Mg interface; and, the Mg-Al interaction layers that were present at the Mg matrix/Al 6061 cladding interface exhibited good radiation stability, i.e. no large pores.

  17. Uranium and Plutonium Average Prompt-fission Neutron Energy Spectra (PFNS) from the Analysis of NTS NUEX Data

    NASA Astrophysics Data System (ADS)

    Lestone, J. P.; Shores, E. F.

    2014-05-01

    In neutron experiments (NUEX) conducted at the Nevada Test Site (NTS) by Los Alamos National Laboratory, the time-of-flight of fission-neutrons emitted from nuclear tests were observed by measuring the current generated by the collection of protons scattered from a thin CH2 foil many meters from the nuclear device into a Faraday cup. The time dependence of the Faraday cup current is a measure of the energy spectrum of the neutrons that leak from the device. With good device models and accurate neutron-transport codes, the leakage spectra can be converted into prompt fast-neutron-induced fission-neutron energy spectra. This has been done for two events containing plutonium, and for an earlier event containing uranium. The prompt-fission neutron spectra have been inferred for 1.5-MeV 239Pu(n,f) and 235U(n,f) reactions for outgoing neutron energies from 1.5 to ∼10.5 MeV, in 1-MeV steps. These spectra are in good agreement with the Los Alamos fission model.

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

    SciTech Connect

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

    2013-11-06

    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).

  19. Center For Advanced Energy Studies Overview

    ScienceCinema

    Blackman, Harold

    2016-07-12

    A collaboration between Idaho National Laboratory, Boise State University, Idaho State University and the University of Idaho. Conducts research in nuclear energy, advanced materials, carbon management, bioenergy, energy policy, modeling and simulation, and energy efficiency. Educates next generation of energy workforce. Visit us at www.caesenergy.org.

  20. Center For Advanced Energy Studies Overview

    SciTech Connect

    Blackman, Harold

    2011-01-01

    A collaboration between Idaho National Laboratory, Boise State University, Idaho State University and the University of Idaho. Conducts research in nuclear energy, advanced materials, carbon management, bioenergy, energy policy, modeling and simulation, and energy efficiency. Educates next generation of energy workforce. Visit us at www.caesenergy.org.

  1. ND:GLASS LASER DESIGN FOR LASER ICF FISSION ENERGY (LIFE)

    SciTech Connect

    Caird, J A; Agrawal, V; Bayramian, A; Beach, R; Britten, J; Chen, D; Cross, R; Ebbers, C; Erlandson, A; Feit, M; Freitas, B; Ghosh, C; Haefner, C; Homoelle, D; Ladran, T; Latkowski, J; Molander, W; Murray, J; Rubenchik, S; Schaffers, K; Siders, C W; Stappaerts, E; Sutton, S; Telford, S; Trenholme, J; Barty, C J

    2008-10-28

    We have developed preliminary conceptual laser system designs for the Laser ICF (Inertial Confinement Fusion) Fission Energy (LIFE) application. Our approach leverages experience in high-energy Nd:glass laser technology developed for the National Ignition Facility (NIF), along with high-energy-class diode-pumped solid-state laser (HEC-DPSSL) technology developed for the DOE's High Average Power Laser (HAPL) Program and embodied in LLNL's Mercury laser system. We present laser system designs suitable for both indirect-drive, hot spot ignition and indirect-drive, fast ignition targets. Main amplifiers for both systems use laser-diode-pumped Nd:glass slabs oriented at Brewster's angle, as in NIF, but the slabs are much thinner to allow for cooling by high-velocity helium gas as in the Mercury laser system. We also describe a plan to mass-produce pump-diode lasers to bring diode costs down to the order of $0.01 per Watt of peak output power, as needed to make the LIFE application economically attractive.

  2. Energy Systems Integration: NREL + Advanced Energy (Fact Sheet)

    SciTech Connect

    Not Available

    2015-02-01

    This fact sheet describes the collaboration between NREL and Advanced Energy Industries at the ESIF to test its advanced photovoltaic inverter technology with the ESIF's power hardware-in-the-loop system and megawatt-scale grid simulators.

  3. Biomodal spontaneous fission

    SciTech Connect

    Hulet, E.K. )

    1989-09-26

    Investigations of mass and kinetic-energy distributions from spontaneous fission have been extended in recent years to an isotope of element 104 and, for half-lives, to an isotope of element 108. The results have been surprising in that spontaneous fission half-lives have turned out to be much longer than expected and mass and kinetic- energy distributions were found to abruptly shift away from those of the lighter actinides, showing two modes of fission. These new developments have caused a re-evaluation of our understanding of the fission process, bringing an even deeper appreciation of the role played by nuclear shell effects upon spontaneous fission properties. 16 refs., 10 figs.

  4. Fission Yields and Other Diagnostics for Nuclear Performance

    NASA Astrophysics Data System (ADS)

    Chadwick, M. B.

    2014-06-01

    I summarize advances in our understanding of basic nuclear physics cross sections and decay properties that are needed to characterize the magnitude and energy-dependence of a neutron flux, and to determine the amount of fission burnup in plutonium fuel. The number of fissions that have occurred in a neutron environment can be deduced from measurements of the fission products created, providing that the fission product yields are known accurately. I describe how our understanding of plutonium fission product yields has improved in recent years through a meta-analysis of various measured data, and through identification of fission product yield incident-energy dependencies over the 0.2-2 MeV fast energy region. This led to the resolution of a previous discrepancy between the Los Alamos and Lawrence Livermore National Laboratories in their plutonium yield assessments in the fast energy region, although more experimental work is still needed to resolve discrepancies at 14 MeV. Work is also described that has improved our understanding of (n,2n) cross sections that are used as diagnostics of the high-energy neutron spectrum - both on plutonium and americium, and on the radiochemical detectors yttrium, iridium, and thulium. Finally, some observations are made on the importance of continuing to develop our Evaluated Nuclear Data Files (ENDF) database using physics insights from differential cross section and integral laboratory experiments and from nuclear theory advances.

  5. Fission Yields and Other Diagnostics for Nuclear Performance

    SciTech Connect

    Chadwick, M.B.

    2014-06-15

    I summarize advances in our understanding of basic nuclear physics cross sections and decay properties that are needed to characterize the magnitude and energy-dependence of a neutron flux, and to determine the amount of fission burnup in plutonium fuel. The number of fissions that have occurred in a neutron environment can be deduced from measurements of the fission products created, providing that the fission product yields are known accurately. I describe how our understanding of plutonium fission product yields has improved in recent years through a meta-analysis of various measured data, and through identification of fission product yield incident-energy dependencies over the 0.2-2 MeV fast energy region. This led to the resolution of a previous discrepancy between the Los Alamos and Lawrence Livermore National Laboratories in their plutonium yield assessments in the fast energy region, although more experimental work is still needed to resolve discrepancies at 14 MeV. Work is also described that has improved our understanding of (n,2n) cross sections that are used as diagnostics of the high-energy neutron spectrum – both on plutonium and americium, and on the radiochemical detectors yttrium, iridium, and thulium. Finally, some observations are made on the importance of continuing to develop our Evaluated Nuclear Data Files (ENDF) database using physics insights from differential cross section and integral laboratory experiments and from nuclear theory advances.

  6. Nanoscale Advances in Catalysis and Energy Applications

    SciTech Connect

    Li, Yimin; Somorjai, Gabor A.

    2010-05-12

    In this perspective, we present an overview of nanoscience applications in catalysis, energy conversion, and energy conservation technologies. We discuss how novel physical and chemical properties of nanomaterials can be applied and engineered to meet the advanced material requirements in the new generation of chemical and energy conversion devices. We highlight some of the latest advances in these nanotechnologies and provide an outlook at the major challenges for further developments.

  7. NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION

    SciTech Connect

    OH,S.Y.; CHANG,J.; MUGHABGHAB,S.

    2000-05-11

    Neutron cross section evaluations of the fission-product isotopes, {sup 95}Mo, {sup 99}Tc, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, {sup 141}Nd, {sup 147}Sm, {sup 149}Sm, {sup 150}Sm, {sup 151}Sm, {sup 152}Sm, {sup 153}Eu, {sup 155}Gd, and {sup 157}Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of {sup 155}Gd and {sup 157}Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations.

  8. Thermal fission rates with temperature dependent fission barriers

    NASA Astrophysics Data System (ADS)

    Zhu, Yi; Pei, J. C.

    2016-08-01

    Background: The fission processes of thermal excited nuclei are conventionally studied by statistical models which rely on inputs of phenomenological level densities and potential barriers. Therefore the microscopic descriptions of spontaneous fission and induced fission are very desirable for a unified understanding of various fission processes. Purpose: We propose to study the fission rates, at both low and high temperatures, with microscopically calculated temperature-dependent fission barriers and collective mass parameters. Methods: The fission barriers are calculated by the finite-temperature Skyrme-Hartree-Fock+BCS method. The mass parameters are calculated by the temperature-dependent cranking approximation. The thermal fission rates can be obtained by the imaginary free energy approach at all temperatures, in which fission barriers are naturally temperature dependent. The fission at low temperatures can be described mainly as a barrier-tunneling process. While the fission at high temperatures has to incorporate the reflection above barriers. Results: Our results of spontaneous fission rates reasonably agree with other studies and experiments. The temperature dependencies of fission barrier heights and curvatures have been discussed. The temperature dependent behaviors of mass parameters have also been discussed. The thermal fission rates from low to high temperatures with a smooth connection have been given by different approaches. Conclusions: Since the temperature dependencies of fission barrier heights and curvatures, and the mass parameters can vary rapidly for different nuclei, the microscopic descriptions of thermal fission rates are very valuable. Our studies without free parameters provide a consistent picture to study various fissions such as that in fast-neutron reactors, astrophysical environments, and fusion reactions for superheavy nuclei.

  9. Measurement of Neutron Induced and Spontaneous Fission in Pu-242 at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, Andrii; Wu, C. Y.; Henderson, R.; Couture, A.; Lee, H. Y.; Ullmann, J.; O'Donnell, J. M.; Jandel, M.; Haight, R. C.; Bredeweg, T. A.; Dance Collaboration

    2013-10-01

    Neutron capture and fission reactions are important in nuclear engineering and physics. DANCE (Detector for Advanced Neutron Capture Measurement, LANL) combined with PPAC (avalanche technique based fission tagging detector, LLNL) were used to study neutron induced and spontaneous fission in 242Pu. 2 measurements were performed in 2013. The first experiment was done without the incident neutron beam with the fission tagging ability to study γ-rays emitted in the spontaneous fission of 242Pu. The second one - with the neutron beam to measure both the neutron capture and fission reactions. This is the first direct measurement of prompt fission γ-rays in 242Pu. The γ-ray multiplicity, γ-ray energy, and total energy of γ-rays per fission in 242Pu will be presented. These distributions of the 242Pu spontaneous fission will be compared to those in the 241Pu neutron induced fission. This work was performed under the auspices of the US Department of Energy by Los Alamos National Laboratory under Contract DE-AC52-06NA25396 and Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

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

    DOEpatents

    Norman, Eric B.; Prussin, Stanley G.

    2007-10-02

    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.

  11. Fission induced plasmas

    NASA Technical Reports Server (NTRS)

    Harries, W. L.

    1977-01-01

    The possibility of creating a plasma from fission fragments was investigated, as well as the probability of utilizing the energy of these particles to create population inversion leading to laser action. Eventually, it is hoped that the same medium could be used for both fissioning and lasing, thus avoiding inefficiences in converting one form of energy to the other. A central problem in understanding a fission induced plasma is to obtain an accurate model of the electron behavior; some calculations are presented to this end. The calculations are simple, providing a compendium of processes for reference.

  12. Energy Dependence of Neutron-Induced Fission Product Yields of 235U, 238U and 239Pu Between 0.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, Matthew; Tornow, Werner; Tonchev, Anton; Vieira, Dave; Wilhelmy, Jerry; Arnold, Charles; Fowler, Malcolm; Stoyer, Mark

    2014-09-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements have been performed. The energy dependence of a number of cumulative fission products between 0.5 and 14.8 MeV have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of activation utilizing specially designed dual-fission chambers and γ-ray counting. The dual-fission chambers are back-to-back ionization chambers encasing a target with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the fission rate in the activation target with no reference to the fission cross-section, reducing uncertainties. γ-ray counting was performed on well-shield HPGe detectors over a period of 2 months per activation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 4.6 and 14.8 MeV.

  13. Neutron Induced Fission Measurements of ^242mAm at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, A.; Wu, C. Y.; Macri, R. A.; Agvaanlusan, U.; Parker, W. E.; Wilk, P. A.; Becker, J. A.; Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Keksis, A. L.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D.; Wilhelmy, J. B.; Wouters, J. M.

    2010-11-01

    Neutron capture and fission reactions on actinieds often present challenges in measuring each of the reaction. Fission tagging detector used along with the Detector for Advanced Neutron Capture Experiments (DANCE) provides a way to measure (n,f) and (n,γ) reactions simultaneously. DANCE was used to measure ^242mAm(n,f) reaction along with a custom made fission-tagging parallel plate avalanche counter (PPAC). The results on fission related γ-ray multiplicity distribution, the ^242mAm(n,f) cross section, and the average γ-ray energy distribution are presented.

  14. Advanced Energy Projects, FY 1993

    NASA Astrophysics Data System (ADS)

    1993-09-01

    AEP has been supporting research on novel materials for energy technology, renewable and biodegradable materials, new uses for scientific discoveries, alternate pathways to energy efficiency, alternative energy sources, innovative approaches to waste treatment and reduction, etc. The summaries are grouped according to projects active in FY 1993, Phase 1 SBIR projects, and Phase 2 SBIR projects. Investigator and institutional indexes are included.

  15. Investigation of the maximum accessible kinetic energy of fragments in the neutron-induced fission of {sup 238}U nuclei

    SciTech Connect

    Khryachkov, V. A. Bondarenko, I. P.; Ivanova, T. A.; Kuzminov, B. D.; Semenova, N. N.; Sergachev, A. I.

    2013-03-15

    The masses, total kinetic energies (TKE), and emission angles of fragments originating from the fission of {sup 238}U nuclei that was induced by 5- and 6.5-MeV neutrons were measured by using digital methods for processing signals. A detailed analysis of the shape of digital signals made it possible to reduce substantially the contribution of fragments whose TKE values were distorted because of a superimposition of signals from recoil protons and from alpha particles produced in the spontaneous decay of uranium. The total statistics exceeded two million events for either neutron energy, and this permitted performing a detailed analysis of fission-fragment yields in the region of the highest attainable TKE values. An analysis of fragment yields made it possible to draw specific conclusions on the structure of the potential surface of fissile nuclei.

  16. Characteristic features of first and second moments of fission-fragment energy distribution as functions of nucleon composition

    SciTech Connect

    Gruzintsev, E.N.; Itkis, M.G.; Mul'gin, S.I.; Okolovich, V.N.; Rusanov, A.Y.; Serdyuk, O.I.; Smirenkin, G.N.; Subbotin, M.I.

    1988-08-01

    We discuss the totality of experimental data obtained at the Alma-Ata isochronous cyclotron for the mean kinetic energy /similar to/(E/sub k/) and energy dispersion sigma/sub E//sup 2/ for nuclei with Z = 68--85, A = 165--213. The dependences of these first two moments of the E/sub k/ distribution as functions of the nucleon composition of the fissioning nucleus are found to have a new feature: a ''break'' in the curve in the vicinity of (Z/sup 2//A/sup 1//sup ///sup 3/)/sub 0/approx. =1000. This effect is due to the fact that the descent-to-scission stage is absent for fissioning nuclei with Z/sup 2//A/sup 1//sup ///sup 3/<(Z/sup 2//A/sup 1//sup ///sup 3/)/sub 0/.

  17. Interpretation of the low energy fission process in the framework of dinuclear system conception

    NASA Astrophysics Data System (ADS)

    Volkov, V. V.; Kalandarov, Sh. A.

    2016-03-01

    The possibility of the interpretation of fission of heavy nuclei as the process of formation, evolution and decay of dinuclear system is discussed. The interpretation is based on the nuclear interaction data obtained in heavy-ion nuclear physics investigations.

  18. Molten Salt Fuel Version of Laser Inertial Fusion Fission Energy (LIFE)

    SciTech Connect

    Moir, R W; Shaw, H F; Caro, A; Kaufman, L; Latkowski, J F; Powers, J; Turchi, P A

    2008-10-24

    Molten salt with dissolved uranium is being considered for the Laser Inertial Confinement Fusion Fission Energy (LIFE) fission blanket as a backup in case a solid-fuel version cannot meet the performance objectives, for example because of radiation damage of the solid materials. Molten salt is not damaged by radiation and therefore could likely achieve the desired high burnup (>99%) of heavy atoms of {sup 238}U. A perceived disadvantage is the possibility that the circulating molten salt could lend itself to misuse (proliferation) by making separation of fissile material easier than for the solid-fuel case. The molten salt composition being considered is the eutectic mixture of 73 mol% LiF and 27 mol% UF{sub 4}, whose melting point is 490 C. The use of {sup 232}Th as a fuel is also being studied. ({sup 232}Th does not produce Pu under neutron irradiation.) The temperature of the molten salt would be {approx}550 C at the inlet (60 C above the solidus temperature) and {approx}650 C at the outlet. Mixtures of U and Th are being considered. To minimize corrosion of structural materials, the molten salt would also contain a small amount ({approx}1 mol%) of UF{sub 3}. The same beryllium neutron multiplier could be used as in the solid fuel case; alternatively, a liquid lithium or liquid lead multiplier could be used. Insuring that the solubility of Pu{sup 3+} in the melt is not exceeded is a design criterion. To mitigate corrosion of the steel, a refractory coating such as tungsten similar to the first wall facing the fusion source is suggested in the high-neutron-flux regions; and in low-neutron-flux regions, including the piping and heat exchangers, a nickel alloy, Hastelloy, would be used. These material choices parallel those made for the Molten Salt Reactor Experiment (MSRE) at ORNL. The nuclear performance is better than the solid fuel case. At the beginning of life, the tritium breeding ratio is unity and the plutonium plus {sup 233}U production rate is {approx}0

  19. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 1: Solar energy

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    The utilization of solar energy to meet the energy needs of the U.S. is discussed. Topics discussed include: availability of solar energy, solar energy collectors, heating for houses and buildings, solar water heater, electric power generation, and ocean thermal power.

  20. Advanced Energy Retrofit Guide Office Buildings

    SciTech Connect

    Liu, Guopeng; Liu, Bing; Wang, Weimin; Zhang, Jian; Athalye, Rahul A.; Moser, Dave; Crowe, Eliot; Bengtson, Nick; Effinger, Mark; Webster, Lia; Hatten, Mike

    2011-09-27

    The Advanced Energy Retrofit Guide for Office Buildings is a component of the Department of Energy’s Advanced Energy Retrofit Guides for Existing Buildings series. The aim of the guides is to facilitate a rapid escalation in the number of energy efficiency projects in existing buildings and to enhance the quality and depth of those projects. By presenting general project planning guidance as well as financial payback metrics for the most common energy efficiency measures, these guides provide a practical roadmap to effectively planning and implementing performance improvements for existing buildings.

  1. Advanced Energy Retrofit Guide Retail Buildings

    SciTech Connect

    Liu, Guopeng; Liu, Bing; Zhang, Jian; Wang, Weimin; Athalye, Rahul A.; Moser, Dave; Crowe, Eliot; Bengtson, Nick; Effinger, Mark; Webster, Lia; Hatten, Mike

    2011-09-19

    The Advanced Energy Retrofit Guide for Retail Buildings is a component of the Department of Energy’s Advanced Energy Retrofit Guides for Existing Buildings series. The aim of the guides is to facilitate a rapid escalation in the number of energy efficiency projects in existing buildings and to enhance the quality and depth of those projects. By presenting general project planning guidance as well as financial payback metrics for the most common energy efficiency measures, these guides provide a practical roadmap to effectively planning and implementing performance improvements for existing buildings.

  2. Center for Advanced Energy Studies Program Plan

    SciTech Connect

    Kevin Kostelnik

    2005-09-01

    The world is facing critical energy-related challenges regarding world and national energy demands, advanced science and energy technology delivery, nuclear engineering educational shortfalls, and adequately trained technical staff. Resolution of these issues is important for the United States to ensure a secure and affordable energy supply, which is essential for maintaining U.S. national security, continued economic prosperity, and future sustainable development. One way that the U.S. Department of Energy (DOE) is addressing these challenges is by tasking the Battelle Energy Alliance, LLC (BEA) with developing the Center for Advanced Energy Studies (CAES) at the Idaho National Laboratory (INL). By 2015, CAES will be a self-sustaining, world-class, academic and research institution where the INL; DOE; Idaho, regional, and other national universities; and the international community will cooperate to conduct critical energy-related research, classroom instruction, technical training, policy conceptualization, public dialogue, and other events.

  3. Experimental study of the three-component structure of mass-energy distributions of fission fragments of nuclei in the vicinity of Pb

    SciTech Connect

    Gruzintsev, E.N.; Itkis, M.G.; Kotlov, Y.V.; Okolovich, V.N.; Rusanov, A.Y.; Smirenkin, G.N.

    1988-05-01

    Measurements and a regression analysis of mass-energy distributions of fission fragments of the nuclei /sup 213/At, /sup 210/Po, and /sup 205/Bi were carried out, demonstrating a three-component structure in the kinetic energy spectra of fragments. The nature of this phenomenon is discussed, as well as its similarity to the recently observed bimodal spontaneous fission of nuclei in the vicinity of Fm.

  4. Determination of Fission Product Yields of 235U, 238U and 239Pu for Neutron Energies from 0.5 to 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, Matthew; Arnold, Charles; Becker, John; Bhatia, Chitra; Bhike, Megha; Fallin, Brent; Fowler, Malcolm; Howell, Calvin; Kelley, John; Stoyer, Mark; Tonchev, Anton; Tornow, Werner; Viera, David; Wilhelmy, Jerry

    2013-10-01

    A joint TUNL-LANL-LLNL collaboration has been formed to study the issue of possible energy dependences for fission product isotopes. Work has been carried out at the TUNL 10 MV Tandem accelerator which produces nearly mono-energetic neutrons via either 2H(d,n)3He,3H(d,n)4He, or 3H(p,n)3He reactions. Three dual fission ionization chambers dedicated to 235U, 238U and 239Pu thick target foils and thin monitor foils respectively, were exposed to the neutron beams. After irradiation, thick target foils were gamma counted over a period of 1-2 months and characteristic gamma rays from fission products were recorded using HPGe detectors at TUNL's low background counting area. Using the dual fission chambers fission product yields relative to total number of fissions were determined at a high precision of 2-3% as well as absolute fission product yields at a lower precision of 5-6%. Results will be presented for a number of fission product isotopes at 1.38, 4.6 and 14.8 MeV as well as preliminary results at 9 MeV.

  5. Neutronics Design of a Thorium-Fueled Fission Blanket for LIFE (Laser Inertial Fusion-based Energy)

    SciTech Connect

    Powers, J; Abbott, R; Fratoni, M; Kramer, K; Latkowski, J; Seifried, J; Taylor, J

    2010-03-08

    The Laser Inertial Fusion-based Energy (LIFE) project at LLNL includes development of hybrid fusion-fission systems for energy generation. These hybrid LIFE engines use high-energy neutrons from laser-based inertial confinement fusion to drive a subcritical blanket of fission fuel that surrounds the fusion chamber. The fission blanket contains TRISO fuel particles packed into pebbles in a flowing bed geometry cooled by a molten salt (flibe). LIFE engines using a thorium fuel cycle provide potential improvements in overall fuel cycle performance and resource utilization compared to using depleted uranium (DU) and may minimize waste repository and proliferation concerns. A preliminary engine design with an initial loading of 40 metric tons of thorium can maintain a power level of 2000 MW{sub th} for about 55 years, at which point the fuel reaches an average burnup level of about 75% FIMA. Acceptable performance was achieved without using any zero-flux environment 'cooling periods' to allow {sup 233}Pa to decay to {sup 233}U; thorium undergoes constant irradiation in this LIFE engine design to minimize proliferation risks and fuel inventory. Vast reductions in end-of-life (EOL) transuranic (TRU) inventories compared to those produced by a similar uranium system suggest reduced proliferation risks. Decay heat generation in discharge fuel appears lower for a thorium LIFE engine than a DU engine but differences in radioactive ingestion hazard are less conclusive. Future efforts on development of thorium-fueled LIFE fission blankets engine development will include design optimization, fuel performance analysis work, and further waste disposal and nonproliferation analyses.

  6. Energy measurement of prompt fission neutrons in 239Pu(n,f) for incident neutron energies from 1 to 200 MeV

    SciTech Connect

    Haight, Robert C; Devlin, Matthew J; Nelson, Ronald O; O' Donnell, John M; Chatillon, Audrey; Granier, Thierry; Taieb, Julien; Belier, Gilbert; Laurent, Benoit; Noda, Shusaku

    2010-01-01

    An experimental campaign was started in 2002 in the framework of a collaboration belween CEA-DAM and the Los Alamos National Laboratory to measure the prompt fission neutron spectra (PFNS) for incident neutron energies from 1 to 200 MeV with consistent error uncertainties over the whole energy range. The prompt neutron spectra in {sup 235,238}U(n,f) and {sup 237}Np(n,f) have been already studied successfully. A first attempt to characterize the prompt neutrons emitted during the fission of the {sup 239}Pu was done in 2007. This contribution will focus on the results obtained during the final experiment to measure the PFNS in {sup 239}Pu(n,f) performed in 2008. Prompt fission neutron spectra in the neutron-induced fission of {sup 239}Pu have been measured for incident neutron energies from 1 to 200 MeV at the Los Alamos Neutron Science Center. Mean energies obtained from the spectra are discussed and compared to theoretical model calculation.

  7. Neutronic Analysis of the Laser Inertial Confinement Fusion-Fission Energy (LIFE) Engine Using Various Thorium Molten Salts

    NASA Astrophysics Data System (ADS)

    Acır, Adem

    2013-08-01

    In this study, a neutronic performance of the Laser Inertial Confinement Fusion Fission Energy (LIFE) molten salt blanket is investigated. Neutronic calculations are performed by using XSDRNPM/SCALE5 codes in S8-P3 approximation. The thorium molten salt composition considered in this calculation is 75 % LiF—25 % ThF4, 75 % LiF—24 % ThF4—1 % 233UF4, 75 % LiF—23 % ThF4—2 % 233UF4. Also, effects of the 6Li enrichment in molten salt are performed for all heavy metal salt. The radiation damage behaviors of SS-304 structural material with respect to higher fissionable fuel content and 6Li enrichment are computed. By higher fissionable fuel content in molten salt and with 6Li enrichment (20 and 50 %) in the coolant in form of 75 % LiF—23 % ThF4—2 % 233UF4, an initial TBR >1.05 can be realized. On the other hand, the 75 % LiF—25 % ThF4 or 75 % LiF—24 % ThF4—1 % 233UF4 molten salt fuel as regards maintained tritium self-sufficiency is not suitable as regards improving neutronic performance of LIFE engine. A high quality fissile fuel with a rate of ~2,850 kg/year of 233U can be produced with 75 % LiF—23 % ThF4—2 % 233UF4. The energy multiplication factor is increased with high rate fission reactions of 233U occurring in the molten salt zone. Major damage mechanisms in SS-304 first wall stell have been computed as DPA = 48 and He = 132 appm per year with 75 % LiF—23 % ThF4—2 % 233UF4. This implies a replacement of the SS-304 first wall stell of every between 3 and 4 years.

  8. Determination of Fission Product Yields of 235U, 238U and 239Pu for Neutron Energies from 0.5 to 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, Matthew; Arnold, Charles; Becker, John; Bhatia, Chitra; Bhike, Megha; Fowler, Malcolm; Howell, Calvin; Kelley, John; Stoyer, Mark; Tonchev, Anton; Tornow, Werner; Vieira, Dave; Wilhelmy, Jerry

    2014-03-01

    A joint TUNL-LANL-LLNL collaboration has been formed to study the issue of possible energy dependences for certain fission product isotopes. Work has been carried out at the TUNL 10 MV Tandem accelerator which produces nearly mono-energetic neutrons via either 2H(d,n)3He,3H(d,n)4He,or3H(p,n)3He reactions. Three dual fission ionization chambers dedicated to 235U, 238U and 239Pu thick target foils and thin monitor foils respectively, were exposed to the neutron beams. After irradiation, thick target foils were gamma counted over a period of 1-2 months and characteristic gamma rays from fission products were recorded using HPGe detectors at TUNL's low background counting area. Using the dual fission chambers, relative fission product yield were determined at a high precision of 2-3 % as well as absolute fission product yields at a lower precision of 5-6 %. Preliminary results will be presented for a number of fission product isotopes over the incident neutron energy range of 0.5 to 14.8 MeV.

  9. 50% Advanced Energy Design Guides: Preprint

    SciTech Connect

    Bonnema, E.; Leach, M.; Pless, S.; Liu, B.; Wang, W.; Thornton, B.; Williams, J.

    2012-07-01

    This paper presents the process, methodology, and assumptions for the development of the 50% Energy Savings Advanced Energy Design Guides (AEDGs), a design guidance document that provides specific recommendations for achieving 50% energy savings above the requirements of ANSI/ASHRAE/IESNA Standard 90.1-2004 in four building types: (1) Small to medium office buildings, (2) K-12 school buildings, (3) Medium to big box retail buildings, (4) Large hospital buildings.

  10. Spontaneous fission properties of sup 258 Fm, sup 259 Md, sup 260 Md, sup 258 No, and sup 260 (104): Bimodal fission

    SciTech Connect

    Hulet, E.K.; Wild, J.F.; Dougan, R.J.; Lougheed, R.W.; Landrum, J.H.; Dougan, A.D.; Baisden, P.A.; Henderson, C.M.; Dupzyk, R.J. ); Hahn, R.L.; and others

    1989-08-01

    We have measured the mass and kinetic-energy distributions from the spontaneous fission of {sup 258}Fm, {sup 258}No, {sup 259}Md, {sup 260}Md, and {sup 260}(104). All are observed to fission with a symmetrical division of mass. The total-kinetic-energy distributions strongly deviated from the Gaussian shape characteristically found in the fission of all other actinides. When the total-kinetic-energy distributions are resolved into two Gaussians, the constituent peaks lie near 200 and 233 MeV. We conclude that both low- and high-energy fission modes occur in four of the five nuclides studied. We call this property bimodal fission.'' Even though both modes are possible in the same nuclide, one generally predominates. We offer an explanation for each mode based on shell structures of the fissioning nucleus and of its fragments. The appearance of both modes of fission in this region of the nuclide chart seems to be a coincidence in that the opportunity to divide into near doubly magic Sn fragments occurs in the same region where the second fission barrier is expected to drop in energy below the ground state of the fissioning nucleus. Appropriate paths on the potential-energy surface of deformation have been found by theorists, but no physical grounds have been advanced that would allow the near equal populations we observe traveling each path. We suggest that this failure to find a reason for somewhat equal branching may be a fundamental flaw of current fission models. Assuming the proposed origins of these modes are correct, we conclude the low-energy, but also mass-symmetrical mode is likely to extend to far heavier nuclei. The high-energy mode will be restricted to a smaller region, a realm of nuclei defined by the proximity of the fragments to the strong neutron and proton shells in {sup 132}Sn.

  11. An experimental measurement of the energy loss of californium fission fragments in air — a comparison with calculations

    NASA Astrophysics Data System (ADS)

    Reier, Melvin

    1988-04-01

    Precision measurements were made of the energy of the light and heavy fission fragments of 25298Cf in air at thicknesses from zero to 1.235 mgcm 2. A least square fit was made to each set of data. The derivative of each analytical expression yields the linear energy transfer (LET) vs air thickness. Results indicate that over the range of data in these measurements, better agreement is obtained with the calculations of Northcliffe and Schilling (ref. [1]: Nucl. Data Tab. A7 (1970) 233) than with those of Ziegler (ref. [2]: Stopping and Ranges of Ions in Matter, Vol 5 (Pergamon, New York 1980)

  12. NEMO: Advanced energy systems and technologies

    NASA Astrophysics Data System (ADS)

    Lund, P.

    In this report, the contents and major results of the national research program on advanced energy system and technologies (NEMO) are presented. The NEMO-program was one of the energy research programs of the Ministry of Trade and Industry during 1988-1992. Helsinki University of Technology had the responsibility of the overall coordination of the program. NEMO has been the largest resource allocation into advanced energy systems in Finland so far. The total budget was 70 million FIM. The focus of the program has been in solar energy, wind power, and energy storage. Hydrogen and fuel cells have been included in smaller amount. On all major fields of the NEMO-program, useful and high quality results have been obtained. Results of international significance include among others arctic wind energy, new approaches for the energy storage problem in solar energy applications, and the development of a completely new storage battery. International collaboration has been given high priority. The NEMO-program has also been active in informing the industries of the various business and utilization possibilities that advanced energy technologies offer. For example, major demonstration plants of each technology group have been realized. It is recommended that the further R and D should be still more focused on commercial applications. Through research efforts at universities, a good technology base should be maintained, whereas the industries should take a stronger position in commercializing new technology. Parallel to technology R and D, more public resources should be allocated for market introduction.

  13. Advanced Energy Efficient Roof System

    SciTech Connect

    Jane Davidson

    2008-09-30

    Energy consumption in buildings represents 40 percent of primary U.S. energy consumption, split almost equally between residential (22%) and commercial (18%) buildings.1 Space heating (31%) and cooling (12%) account for approximately 9 quadrillion Btu. Improvements in the building envelope can have a significant impact on reducing energy consumption. Thermal losses (or gains) from the roof make up 14 percent of the building component energy load. Infiltration through the building envelope, including the roof, accounts for an additional 28 percent of the heating loads and 16 percent of the cooling loads. These figures provide a strong incentive to develop and implement more energy efficient roof systems. The roof is perhaps the most challenging component of the building envelope to change for many reasons. The engineered roof truss, which has been around since 1956, is relatively low cost and is the industry standard. The roof has multiple functions. A typical wood frame home lasts a long time. Building codes vary across the country. Customer and trade acceptance of new building products and materials may impede market penetration. The energy savings of a new roof system must be balanced with other requirements such as first and life-cycle costs, durability, appearance, and ease of construction. Conventional residential roof construction utilizes closely spaced roof trusses supporting a layer of sheathing and roofing materials. Gypsum board is typically attached to the lower chord of the trusses forming the finished ceiling for the occupied space. Often in warmer climates, the HVAC system and ducts are placed in the unconditioned and otherwise unusable attic. High temperature differentials and leaky ducts result in thermal losses. Penetrations through the ceilings are notoriously difficult to seal and lead to moisture and air infiltration. These issues all contribute to greater energy use and have led builders to consider construction of a conditioned attic. The

  14. Spontaneous Fission

    DOE R&D Accomplishments Database

    Segre, Emilio

    1950-11-22

    The first attempt to discover spontaneous fission in uranium was made by [Willard] Libby, who, however, failed to detect it on account of the smallness of effect. In 1940, [K. A.] Petrzhak and [G. N.] Flerov, using more sensitive methods, discovered spontaneous fission in uranium and gave some rough estimates of the spontaneous fission decay constant of this substance. Subsequently, extensive experimental work on the subject has been performed by several investigators and will be quoted in the various sections. [N.] Bohr and [A.] Wheeler have given a theory of the effect based on the usual ideas of penetration of potential barriers. On this project spontaneous fission has been studied for the past several years in an effort to obtain a complete picture of the phenomenon. For this purpose the spontaneous fission decay constants {lambda} have been measured for separated isotopes of the heavy elements wherever possible. Moreover, the number {nu} of neutrons emitted per fission has been measured wherever feasible, and other characteristics of the spontaneous fission process have been studied. This report summarizes the spontaneous fission work done at Los Alamos up to January 1, 1945. A chronological record of the work is contained in the Los Alamos monthly reports.

  15. Advanced Energy Projects FY 1996 research summaries

    SciTech Connect

    1996-09-01

    The mission of the Advanced Energy Projects Division (AEP) is to explore the scientific feasibility of novel energy-related concepts. These concepts are typically at an early stage of scientific development and, therefore, are premature for consideration by applied research or technology development programs. The portfolio of projects is dynamic, but reflects the broad role of the Department in supporting research and development for improving the Nation`s energy posture. Topical areas presently receiving support include: alternative energy sources; innovative concepts for energy conversion and storage; alternate pathways to energy efficiency; exploring uses of new scientific discoveries; biologically-based energy concepts; renewable and biodegradable materials; novel materials for energy technology; and innovative approaches to waste treatment and reduction. Summaries of the 70 projects currently being supported are presented. Appendices contain budget information and investigator and institutional indices.

  16. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, M.; Arnold, C.; Bredeweg, T.; Vieira, D.; Wilhelmy, J.; Tonchev, A.; Stoyer, M.; Bhike, M.; Krishichayan, F.; Tornow, W.; Fowler, M.

    2015-10-01

    Under a joint collaboration between TUNL-LANL-LLNL, a set of absolute fission product yield measurements has been performed. The energy dependence of a number of cumulative fission product yields (FPY) have been measured using quasi-monoenergetic neutron beams for three actinide targets, 235U, 238U and 239Pu, between 0.5 and 14.8 MeV. The FPYs were measured by a combination of fission counting using specially designed dual-fission chambers and ?-ray counting. Each dual-fission chamber is a back-to-back ionization chamber encasing an activation target in the center with thin deposits of the same target isotope in each chamber. This method allows for the direct measurement of the total number of fissions in the activation target with no reference to the fission cross-section, thus reducing uncertainties. ?-ray counting of the activation target was performed on well-shielded HPGe detectors over a period of 2 months post irradiation to properly identify fission products. Reported are absolute cumulative fission product yields for incident neutron energies of 0.5, 1.37, 2.4, 3.6, 4.6, 5.5, 7.5, 8.9 and 14.8 MeV. These results are compared to previous measurements and theoretical estimates. This work was performed under the auspices of the USDoE by Los Alamos National Security, LLC under Contract DE-AC52-06NA25396.

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

    SciTech Connect

    Kern, K.; Becker, M.; Broeders, C.

    2012-07-01

    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)

  18. The New Center for Advanced Energy Studies

    SciTech Connect

    L.J. Bond; K. Kostelnik; R.A. Wharton; A. Kadak

    2006-06-01

    A secure and affordable energy supply is essential for achieving U.S. national security, in continuing U.S. prosperity and in laying the foundation to enable future economic growth. The next generation energy workforce in the U.S. is a critical element in meeting both national and global energy needs. The Center for Advanced Energy Studies (CAES) was established in 2005 in response to U.S. Department of Energy (DOE) requirements. CAES, located at the new Idaho National Laboratory (INL), will address critical energy education, research, policy study and training needs. CAES is a unique joint partnership between the Battelle Energy Alliance (BEA), the State of Idaho, an Idaho University Consortium (IUC), and a National University Consortium (NUC). CAES will be based in a new facility that will foster collaborative academic and research efforts among participating institutions.

  19. Prompt fission gamma-ray studies at DANCE

    DOE PAGES

    Jandel, M.; Rusev, G.; Bond, E. M.; Bredeweg, T. A.; Chadwick, M. B.; Couture, A.; Fowler, M.. M; Haight, R. C.; Kawano, T.; Keksis, A. L.; et al

    2014-11-26

    Measurements of correlated data on prompt-fission γ-rays (PFG) have been carried out for various actinide isotopes in recent years using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL). We have developed a model that conveniently parametrizes the correlated data of γ-ray multiplicity and energy. New results on two- dimensional prompt-fission γ-ray multiplicity versus energy distributions from spontaneous fission on ²⁵²Cf and neutron-induced fission on 242mAm are presented together with previously obtained results on 233,235U and ²³⁹Pu. Correlated PFG data from ²⁵²Cf are also compared to results of the detailed theoretical model developed at LANL,more » for different thresholds of PFG energies. Future plans to measure correlated data on fission fragments, prompt fission neutrons and γ-rays at DANCE are presented.« less

  20. Singlet exciton fission photovoltaics.

    PubMed

    Lee, Jiye; Jadhav, Priya; Reusswig, Philip D; Yost, Shane R; Thompson, Nicholas J; Congreve, Daniel N; Hontz, Eric; Van Voorhis, Troy; Baldo, Marc A

    2013-06-18

    Singlet exciton fission, a process that generates two excitons from a single photon, is perhaps the most efficient of the various multiexciton-generation processes studied to date, offering the potential to increase the efficiency of solar devices. But its unique characteristic, splitting a photogenerated singlet exciton into two dark triplet states, means that the empty absorption region between the singlet and triplet excitons must be filled by adding another material that captures low-energy photons. This has required the development of specialized device architectures. In this Account, we review work to develop devices that harness the theoretical benefits of singlet exciton fission. First, we discuss singlet fission in the archetypal material, pentacene. Pentacene-based photovoltaic devices typically show high external and internal quantum efficiencies. They have enabled researchers to characterize fission, including yield and the impact of competing loss processes, within functional devices. We review in situ probes of singlet fission that modulate the photocurrent using a magnetic field. We also summarize studies of the dissociation of triplet excitons into charge at the pentacene-buckyball (C60) donor-acceptor interface. Multiple independent measurements confirm that pentacene triplet excitons can dissociate at the C60 interface despite their relatively low energy. Because triplet excitons produced by singlet fission each have no more than half the energy of the original photoexcitation, they limit the potential open circuit voltage within a solar cell. Thus, if singlet fission is to increase the overall efficiency of a solar cell and not just double the photocurrent at the cost of halving the voltage, it is necessary to also harvest photons in the absorption gap between the singlet and triplet energies of the singlet fission material. We review two device architectures that attempt this using long-wavelength materials: a three-layer structure that uses

  1. Veterans Advancing Clean Energy and Climate

    ScienceCinema

    Kopser, Joseph; Marr, Andrea; Perez-Halperin, Elizabeth; Eckstein, Robin; Moniz, Ernest

    2016-07-12

    The Champions of Change series highlights ordinary Americans who are doing extraordinary things in their communities to out-innovate, out-educate and out-build the rest of the world. On November 5, 2013, the White House honored 12 veterans and leaders who are using the skills they learned in the armed services to advance the clean energy economy.

  2. Veterans Advancing Clean Energy and Climate

    SciTech Connect

    Kopser, Joseph; Marr, Andrea; Perez-Halperin, Elizabeth; Eckstein, Robin; Moniz, Ernest

    2013-11-11

    The Champions of Change series highlights ordinary Americans who are doing extraordinary things in their communities to out-innovate, out-educate and out-build the rest of the world. On November 5, 2013, the White House honored 12 veterans and leaders who are using the skills they learned in the armed services to advance the clean energy economy.

  3. Effect of transverse vibrations of fissile nuclei on the angular and spin distributions of low-energy fission fragments

    NASA Astrophysics Data System (ADS)

    Bunakov, V. E.; Kadmensky, S. G.; Lyubashevsky, D. E.

    2016-05-01

    It is shown that A. Bohr's classic theory of angular distributions of fragments originating from low-energy fission should be supplemented with quantum corrections based on the involvement of a superposition of a very large number of angular momenta L m in the description of the relative motion of fragments flying apart along the straight line coincidentwith the symmetry axis. It is revealed that quantum zero-point wriggling-type vibrations of the fissile system in the vicinity of its scission point are a source of these angular momenta and of high fragment spins observed experimentally.

  4. Low-energy fission investigated in reactions of 750 AMeV238U-ions with Pb and Be targets. I. Nuclear charge distributions

    NASA Astrophysics Data System (ADS)

    Armbruster, P.; Bernas, M.; Czajkowski, S.; Geissel, H.; Aumann, T.; Dessagne, Ph.; Donzaud, C.; Hanelt, E.; Heinz, A.; Hesse, M.; Kozhuharov, C.; Miehe, Ch.; Münzenberg, G.; Pfützner, M.; Schmidt, K.-H.; Schwab, W.; Stéphan, C.; Sümmerer, K.; Tassan-Got, L.; Voss, B.

    1996-12-01

    Charge distributions of fragments from low energy nuclear fission are investigated in reactions of highly fissile238U projectiles at relativistic energies (750 A·MeV) with a heavy (Pb) and a light (Be) target. The fully stripped fission fragments are separated by the Fragment Separator (FRS). Their high kinetic energies in the laboratory system allow the identification of all atomic numbers by using Multiple-Sampling Ionization Chambers (MUSIC). The elemental distributions of fragments observed at larger magnetic rigidities than the238U projectiles show asymmetric break-up and odd-even effects. They indicate a low energy fission process, induced mainly by dissociation in the electro-magnetic field for the U/Pb-system, or by peripheral nuclear interactions for the U/Be-system.

  5. Flywheel energy storage advances using HTS bearings.

    SciTech Connect

    Mulcahy, T. M.

    1998-09-11

    High-Temperature-Superconducting (HT) bearings have the potential to reduce idling losses and make flywheel energy storage economical. Demonstration of large, high-speed flywheels is key to market penetration. Toward this goal, a flywheel system has been developed and tested with 5-kg to 15-kg disk-shaped rotors. Rlm speeds exceeded 400 mls and stored energies were >80 W-hr. Test implementation required technological advances in nearly all aspects of the flywheel system. Features and limitations of the design and tests are discussed, especially those related to achieving additional energy storage.

  6. Time features of delayed neutrons and partial emissive-fission cross sections for the neutron-induced fission of {sup 232}Th nuclei in the energy range 3.2-17.9 MeV

    SciTech Connect

    Roshchenko, V. A. Piksaikin, V. M. Korolev, G. G.; Egorov, A. S.

    2010-06-15

    The energy dependence of the relative abundances of delayed neutrons and the energy dependence of the half-lives of their precursors in the neutron-induced fission of {sup 232}Th nuclei in the energy range 3.2-17.9 MeV were measured for the first time. A systematics of the time features of delayed neutrons is developed. This systematics makes it possible to estimate the half-life of delayed-neutron precursors as a function of the nucleonic composition of fissile nuclei by using a single parameter set for all nuclides. The energy dependence of the partial cross sections for emissive fission in the reaction {sup 232}Th(n, f) was analyzed on the basis of data obtained for the relative abundances of delayed neutrons and the aforementioned half-lives and on the basis of the created systematics of the time features of delayed neutrons. It was shown experimentally for the first time that the decrease in the cross section after the reaction threshold in the fission of {sup 232}Th nuclei (it has a pronounced first-chance plateau) is not an exclusion among the already studied uranium, plutonium, and curium isotopes and complies with theoretical predictions obtained for the respective nuclei with allowance for shell, superfluid, and collective effects in the nuclear-level density and with allowance for preequilibrium neutron emission

  7. Dynamics of fission and heavy ion reactions

    SciTech Connect

    Nix, J.R.; Sierk, A.J.

    1984-05-01

    Recent advances in a unified macroscopic-microscopic description of large-amplitude collective nuclear motion such as occurs in fission and heavy ion reactions are discussed. With the goal of finding observable quantities that depend upon the magnitude and mechanism of nuclear dissipation, one-body dissipation and two-body viscosity within the framework of a generalized Fokker-Planck equation for the time dependence of the distribution function in phase space of collective coordinates and momenta are considered. Proceeding in two separate directions, the generalized Hamilton equations of motion for the first moments of the distribution function with a new shape parametrization and other technical innovations are first solved. This yields the mean translational fission-fragment kinetic energy and mass of a third fragment that sometimes forms between the two end fragments, as well as the energy required for fusion in symmetric heavy-ion reactions and the mass transfer and capture cross section in asymmetric heavy-ion reactions. In a second direction, we specialize to an inverted-oscillator fission barrier and use Kramers' stationary solution to calculate the mean time from the saddle point to scission for a heavy-ion-induced fission reaction for which experimental information is becoming available. 25 references.

  8. Fragment mass and kinetic-energy distributions from spontaneous fission of the neutron-deficient isotopes, 1. 2-s /sup 246/Fm and 38-s /sup 248/Fm

    SciTech Connect

    Hoffman, D.; Lee, D.; Ghiorso, A.; Nurmia, M.; Aleklett, K.

    1980-10-01

    We have measured the mass and kinetic-energy distributions for fragments from the spontaneous fission of 1.2-s /sup 246/Fm and 38-s /sup 248/Fm. The mass distributions are highly asymmetric and the average total kinetic energies of 199 +- 4 MeV and 198 +- 4 MeV, respectively, are consistent with systematics for lower Z actinides. Their properties are in contrast to those of /sup 258/Fm and /sup 259/Fm, whose spontaneous fission results in narrowly symmetric mass distributions accompanied by unusually high total kinetic energies.

  9. Advanced energy projects FY 1994 research summaries

    SciTech Connect

    Not Available

    1994-09-01

    The Division of Advanced Energy Projects (AEP) provides support to explore the feasibility of novel, energy-related concepts that evolve from advances in basic research. These concepts are typically at an early stage of scientific definition and, therefore, are premature for consideration by applied research or technology development programs. The AEP also supports high-risk, exploratory concepts that do not readily fit into a program area but could have several applications that may span scientific disciplines or technical areas. Projects supported by the Division arise from unsolicited ideas and concepts submitted by researchers. The portfolio of projects is dynamic and reflects the broad role of the Department in supporting research and development for improving the Nation`s energy outlook. FY 1994 projects include the following topical areas: novel materials for energy technology; renewable and biodegradable materials; exploring uses of new scientific discoveries; alternate pathways to energy efficiency; alternative energy sources; and innovative approaches to waste treatment and reduction. Summaries are given for 66 projects.

  10. Fission: The first 50 years

    SciTech Connect

    Vandenbosch, R.

    1989-01-01

    The possibility of fission had been largely unanticipated prior to its discovery in 1938. This process, with its dramatically large energy release and its formation of previously unknown nuclides, immediately captured the imagination of the scientific community. Both theoretical and experimental developments occurred at a rapid pace. I will begin my discussion of fission with the far-reaching paper of Bohr and Wheeler, who in little more than half a year laid out a framework for understanding many features of the fission process. I will then turn to our current understanding of a number of aspects of fission. One of these is the pronounced tendency of many nuclear species to fission asymmetrically. In fact, the discovery of fission was based on the identification of barium isotopes produced in asymmetric fission. The dramatic changes in the preferred mass division and kinetic energy release with the addition of only a few neutrons to the spontaneously fissioning Fermium isotopes will be emphasized. The problem of the dynamics of saddle to scission will be discussed---this is one aspect of fission for which we do not have all the answers. Another dynamical effect to be discussed is the apparent failure of transition state theory at high excitation energies. The role of single particle (shell) effects in enriching the structure if the potential energy surface will be explored. Spontaneously fissioning isomers and intermediate structure resonances will be discussed. The recognition that short-lived fission isomers are superdeformed shape isomers has been followed by the recent observation of superdeformed shape isomers in the rare earth region. 18 refs., 3 figs.

  11. Fission fragment driven neutron source

    DOEpatents

    Miller, Lowell G.; Young, Robert C.; Brugger, Robert M.

    1976-01-01

    Fissionable uranium formed into a foil is bombarded with thermal neutrons in the presence of deuterium-tritium gas. The resulting fission fragments impart energy to accelerate deuterium and tritium particles which in turn provide approximately 14 MeV neutrons by the reactions t(d,n).sup.4 He and d(t,n).sup.4 He.

  12. The SPIDER fission fragment spectrometer for fission product yield measurements

    SciTech Connect

    Meierbachtol, K.; Tovesson, F.; Shields, D.; Arnold, C.; Blakeley, R.; Bredeweg, T.; Devlin, M.; Hecht, A. A.; Heffern, L. E.; Jorgenson, J.; Laptev, A.; Mader, D.; O׳Donnell, J. M.; Sierk, A.; White, M.

    2015-04-01

    The SPectrometer for Ion DEtermination in fission Research (SPIDER) developed for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2E–2v method of measuring the kinetic energy (E) and velocity (v) of both outgoing fission products utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). The SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, assembled and tested using 229Th and 252Cf radioactive decay sources. For commissioning, the fully assembled system measured fission products from spontaneous fission of 252Cf. Finally, individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). These mass yield results measured from 252Cf spontaneous fission products are reported from an E–v measurement.

  13. The SPIDER fission fragment spectrometer for fission product yield measurements

    DOE PAGES

    Meierbachtol, K.; Tovesson, F.; Shields, D.; Arnold, C.; Blakeley, R.; Bredeweg, T.; Devlin, M.; Hecht, A. A.; Heffern, L. E.; Jorgenson, J.; et al

    2015-04-01

    The SPectrometer for Ion DEtermination in fission Research (SPIDER) developed for measuring mass yield distributions of fission products from spontaneous and neutron-induced fission. The 2E–2v method of measuring the kinetic energy (E) and velocity (v) of both outgoing fission products utilized, with the goal of measuring the mass of the fission products with an average resolution of 1 atomic mass unit (amu). The SPIDER instrument, consisting of detector components for time-of-flight, trajectory, and energy measurements, assembled and tested using 229Th and 252Cf radioactive decay sources. For commissioning, the fully assembled system measured fission products from spontaneous fission of 252Cf. Finally,more » individual measurement resolutions were met for time-of-flight (250 ps FWHM), spacial resolution (2 mm FHWM), and energy (92 keV FWHM for 8.376 MeV). These mass yield results measured from 252Cf spontaneous fission products are reported from an E–v measurement.« less

  14. Energy dependence of proton induced fission cross sections for heavy nuclei in the energy range 200-1000 MeV

    SciTech Connect

    Kotov, A. A.; Vaishnene, L. A.; Vovchenko, V. G.; Gavrikov, Yu. A.; Poliakov, V. V.; Tverskoy, M. G.; Fedorov, O. Ya.; Chestnov, Yu. A.; Shchetkovskiy, A. I.; Shvedchikov, A. V.; Doroshenko, A. Yu.; Fukahori, T.

    2006-09-15

    Total cross sections for proton induced fission of {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu nuclei were measured in the range 200-1000 MeV with an energy step of 100 MeV. The experiment was carried out at 1 GeV in a PNPI synchrocyclotron. Complementary fragments of the binary fission from a thin target were detected in coincidence by two parallel plate avalanche counters (PPAC) located close to the target. An assembly of the two PPACs and with the target in between them was placed directly into the beam, which provided a large solid angle acceptance. The beam monitoring system employed a scintillation counter telescope that was used for direct proton counting as well as for registration of the elastic pp-scattering events from the auxiliary (CH{sub 2}){sub n} target. The measured energy dependence of the total fission cross sections is presented. The results are compared with other available experimental data as well as with calculations in the frame of the cascade-evaporation model.

  15. Energy from nuclear fission()

    NASA Astrophysics Data System (ADS)

    Ripani, M.

    2015-08-01

    The main features of nuclear fission as physical phenomenon will be revisited, emphasizing its peculiarities with respect to other nuclear reactions. Some basic concepts underlying the operation of nuclear reactors and the main types of reactors will be illustrated, including fast reactors, showing the most important differences among them. The nuclear cycle and radioactive-nuclear-waste production will be also discussed, along with the perspectives offered by next generation nuclear assemblies being proposed. The current situation of nuclear power in the world, its role in reducing carbon emission and the available resources will be briefly illustrated.

  16. Ion exchange in the atomic energy industry with particular reference to actinide and fission product separation

    SciTech Connect

    Jenkins, I.L.

    1984-01-01

    Reviewed are some of the uses of ion exchange processes used by the nuclear industry for the period April, 1978 to April, 1983. The topics dealt with are: thorium, protactinium, uranium, neptunium, plutonium, americium, cesium and actinide-lanthanide separations; the higher actinides - Cm, Bk, Cf, Es and Fm; fission products; ion exchange in the geological disposal of radioactive waste. Consideration is given to safety in the use of ion exchangers and in safe methods of disposal of such materials. Full scale and pilot plant process descriptions are included as well as summaries of laboratory studies. 130 references.

  17. Fission yield measurements at IGISOL

    NASA Astrophysics Data System (ADS)

    Lantz, M.; Al-Adili, A.; Gorelov, D.; Jokinen, A.; Kolhinen, V. S.; Mattera, A.; Moore, I.; Penttilä, H.; Pomp, S.; Prokofiev, A. V.; Rakopoulos, V.; Rinta-Antila, S.; Simutkin, V.; Solders, A.

    2016-06-01

    The fission product yields are an important characteristic of the fission process. In fundamental physics, knowledge of the yield distributions is needed to better understand the fission process. For nuclear energy applications good knowledge of neutroninduced fission-product yields is important for the safe and efficient operation of nuclear power plants. With the Ion Guide Isotope Separator On-Line (IGISOL) technique, products of nuclear reactions are stopped in a buffer gas and then extracted and separated by mass. Thanks to the high resolving power of the JYFLTRAP Penning trap, at University of Jyväskylä, fission products can be isobarically separated, making it possible to measure relative independent fission yields. In some cases it is even possible to resolve isomeric states from the ground state, permitting measurements of isomeric yield ratios. So far the reactions U(p,f) and Th(p,f) have been studied using the IGISOL-JYFLTRAP facility. Recently, a neutron converter target has been developed utilizing the Be(p,xn) reaction. We here present the IGISOL-technique for fission yield measurements and some of the results from the measurements on proton induced fission. We also present the development of the neutron converter target, the characterization of the neutron field and the first tests with neutron-induced fission.

  18. Neutron Transport and Nuclear Burnup Analysis for the Laser Inertial Confinement Fusion-Fission Energy (LIFE) Engine

    SciTech Connect

    Kramer, K J; Latkowski, J F; Abbott, R P; Boyd, J K; Powers, J J; Seifried, J E

    2008-10-24

    Lawrence Livermore National Laboratory is currently developing a hybrid fusion-fission nuclear energy system, called LIFE, to generate power and burn nuclear waste. We utilize inertial confinement fusion to drive a subcritical fission blanket surrounding the fusion chamber. It is composed of TRISO-based fuel cooled by the molten salt flibe. Low-yield (37.5 MJ) targets and a repetition rate of 13.3 Hz produce a 500 MW fusion source that is coupled to the subcritical blanket, which provides an additional gain of 4-8, depending on the fuel. In the present work, we describe the neutron transport and nuclear burnup analysis. We utilize standard analysis tools including, the Monte Carlo N-Particle (MCNP) transport code, ORIGEN2 and Monteburns to perform the nuclear design. These analyses focus primarily on a fuel composed of depleted uranium not requiring chemical reprocessing or enrichment. However, other fuels such as weapons grade plutonium and highly-enriched uranium are also under consideration. In addition, we have developed a methodology using {sup 6}Li as a burnable poison to replace the tritium burned in the fusion targets and to maintain constant power over the lifetime of the engine. The results from depleted uranium analyses suggest up to 99% burnup of actinides is attainable while maintaining full power at 2GW for more than five decades.

  19. Measurement of Fission Product Yields from Fast-Neutron Fission

    NASA Astrophysics Data System (ADS)

    Arnold, C. W.; Bond, E. M.; Bredeweg, T. A.; Fowler, M. M.; Moody, W. A.; Rusev, G.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Henderson, R.; Kenneally, J.; Macri, R.; McNabb, D.; Ryan, C.; Sheets, S.; Stoyer, M. A.; Tonchev, A. P.; Bhatia, C.; Bhike, M.; Fallin, B.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.

    2014-09-01

    One of the aims of the Stockpile Stewardship Program is a reduction of the uncertainties on fission data used for analyzing nuclear test data [1,2]. Fission products such as 147Nd are convenient for determining fission yields because of their relatively high yield per fission (about 2%) and long half-life (10.98 days). A scientific program for measuring fission product yields from 235U,238U and 239Pu targets as a function of bombarding neutron energy (0.1 to 15 MeV) is currently underway using monoenergetic neutron beams produced at the 10 MV Tandem Accelerator at TUNL. Dual-fission chambers are used to determine the rate of fission in targets during activation. Activated targets are counted in highly shielded HPGe detectors over a period of several weeks to identify decaying fission products. To date, data have been collected at neutron bombarding energies 4.6, 9.0, 14.5 and 14.8 MeV. Experimental methods and data reduction techniques are discussed, and some preliminary results are presented.

  20. Solargenix Energy Advanced Parabolic Trough Development

    SciTech Connect

    Gee, R. C.; Hale, M. J.

    2005-11-01

    The Solargenix Advanced Trough Development Project was initiated in the Year 2000 with the support of the DOE CSP Program and, more recently, with the added support of the Nevada Southwest Energy Partnership. Parabolic trough plants are the most mature solar power technology, but no large-scale plants have been built in over a decade. Given this lengthy lull in deployment, our first Project objective was development of improved trough technology for near-term deployment, closely patterned after the best of the prior-generation troughs. The second objective is to develop further improvements in next-generation trough technology that will lead to even larger reductions in the cost of the delivered energy. To date, this Project has successfully developed an advanced trough, which is being deployed on a 1-MW plant in Arizona and will soon be deployed in a 64-MW plant in Nevada. This advanced trough offers a 10% increase in performance and over an 20% decrease in cost, relative to prior-generation troughs.

  1. Neutron Capture and Fission Measurements on Actinides at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, Andrii; Wu, Ching-Yen; Kwan, Elaine; Henderson, Rodger; Gostic, Julie; Ullmann, John; Jandel, Marian; Bredeweg, Todd; Couture, Aaron; Lee, Hye Young; Haight, Robert; O'Donnell, John

    2011-10-01

    Neutron capture and fission measurements on actinides are important in nuclear engineering and physics. DANCE (Detector for Advanced Neutron Capture Measurement build at LANL) together with PPAC (avalanche technique based fission tagging detector designed and fabricated at LLNL) were used to measure the prompt γ-ray energy and multiplicity distributions in the spontaneous fission of 252Cf. These measured spectra together with the unfolded ones will be presented. The unfolding technique will be described. In addition the 238Pu(n , γ) cross section will be presented, which was measured using DANCE alone and also is the first such measurement in a laboratory environment. This work was performed under the auspices of the US Department of Energy by Los Alamos National Laboratory under Contract DE-AC52-06NA25396 and Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  2. Advanced Energy Industries, Inc. SEGIS developments.

    SciTech Connect

    Scharf, Mesa P.; Bower, Ward Isaac; Mills-Price, Michael A.; Sena-Henderson, Lisa; David, Carolyn; Akhil, Abbas Ali; Kuszmaul, Scott S.; Gonzalez, Sigifredo

    2012-03-01

    The Solar Energy Grid Integration Systems (SEGIS) initiative is a three-year, three-stage project that includes conceptual design and market analysis (Stage 1), prototype development/testing (Stage 2), and commercialization (Stage 3). Projects focus on system development of solar technologies, expansion of intelligent renewable energy applications, and connecting large-scale photovoltaic (PV) installations into the electric grid. As documented in this report, Advanced Energy Industries, Inc. (AE), its partners, and Sandia National Laboratories (SNL) successfully collaborated to complete the final stage of the SEGIS initiative, which has guided new technology development and development of methodologies for unification of PV and smart-grid technologies. The combined team met all deliverables throughout the three-year program and commercialized a broad set of the developed technologies.

  3. Advanced Technology Display House. Volume 2: Energy system design concepts

    NASA Technical Reports Server (NTRS)

    Maund, D. H.

    1981-01-01

    The preliminary design concept for the energy systems in the Advanced Technology Display House is analyzed. Residential energy demand, energy conservation, and energy concepts are included. Photovoltaic arrays and REDOX (reduction oxidation) sizes are discussed.

  4. Saving Energy Through Advanced Power Strips (Poster)

    SciTech Connect

    Christensen, D.

    2013-10-01

    Advanced Power Strips (APS) look just like ordinary power strips, except that they have built-in features that are designed to reduce the amount of energy used by many consumer electronics. There are several different types of APSs on the market, but they all operate on the same basic principle of shutting off the supply power to devices that are not in use. By replacing your standard power strip with an APS, you can signifcantly cut the amount of electricity used by your home office and entertainment center devices, and save money on your electric bill. This illustration summarizes the different options.

  5. Advanced Analysis Methods in High Energy Physics

    SciTech Connect

    Pushpalatha C. Bhat

    2001-10-03

    During the coming decade, high energy physics experiments at the Fermilab Tevatron and around the globe will use very sophisticated equipment to record unprecedented amounts of data in the hope of making major discoveries that may unravel some of Nature's deepest mysteries. The discovery of the Higgs boson and signals of new physics may be around the corner. The use of advanced analysis techniques will be crucial in achieving these goals. The author discusses some of the novel methods of analysis that could prove to be particularly valuable for finding evidence of any new physics, for improving precision measurements and for exploring parameter spaces of theoretical models.

  6. Advanced materials for geothermal energy processes

    SciTech Connect

    Kukacka, L.E.

    1985-08-01

    The primary goal of the geothermal materials program is to ensure that the private sector development of geothermal energy resources is not constrained by the availability of technologically and economically viable materials of construction. This requires the performance of long-term high risk GHTD-sponsored materials R and D. Ongoing programs described include high temperature elastomers for dynamic sealing applications, advanced materials for lost circulation control, waste utilization and disposal, corrosion resistant elastomeric liners for well casing, and non-metallic heat exchangers. 9 refs.

  7. Advanced Dark Energy Physics Telescope (ADEPT)

    SciTech Connect

    Charles L. Bennett

    2009-03-26

    In 2006, we proposed to NASA a detailed concept study of ADEPT (the Advanced Dark Energy Physics Telescope), a potential space mission to reliably measure the time-evolution of dark energy by conducting the largest effective volume survey of the universe ever done. A peer-review panel of scientific, management, and technical experts reported back the highest possible 'excellent' rating for ADEPT. We have since made substantial advances in the scientific and technical maturity of the mission design. With this Department of Energy (DOE) award we were granted supplemental funding to support specific extended research items that were not included in the NASA proposal, many of which were intended to broadly advance future dark energy research, as laid out by the Dark Energy Task Force (DETF). The proposed work had three targets: (1) the adaptation of large-format infrared arrays to a 2 micron cut-off; (2) analytical research to improve the understanding of the dark energy figure-of- merit; and (3) extended studies of baryon acoustic oscillation systematic uncertainties. Since the actual award was only for {approx}10% of the proposed amount item (1) was dropped and item (2) work was severely restricted, consistent with the referee reviews of the proposal, although there was considerable contradictions between reviewer comments and several comments that displayed a lack of familiarity with the research. None the less, item (3) was the focus of the work. To characterize the nature of the dark energy, ADEPT is designed to observe baryon acoustic oscillations (BAO) in a large galaxy redshift survey and to obtain substantial numbers of high-redshift Type Ia supernovae (SNe Ia). The 2003 Wilkinson Microwave Anisotropy Probe (WMAP) made a precise determination of the BAO 'standard ruler' scale, as it was imprinted on the cosmic microwave background (CMB) at z {approx} 1090. The standard ruler was also imprinted on the pattern of galaxies, and was first detected in 2005 in Sloan

  8. Solar vs. Fission Surface Power for Mars

    NASA Technical Reports Server (NTRS)

    Rucker, Michelle A.; Oleson, Steve; George, Pat; Landis, Geoffrey A.; Fincannon, James; Bogner, Amee; Jones, Robert E.; Turnbull, Elizabeth; Martini, Michael C.; Gyekenyesi, John Z.; Colozza, Anthony J.; Schmitz, Paul C.; Packard, Thomas W.

    2016-01-01

    crewed expedition mission. Unlike the demonstration mission, a lengthy power outage due to the global dust storms that are known to occur on Mars would pose a safety hazard to a crewed mission. A similar fission versus solar power trade study performed by NASA in 2007 concluded that fission power was more reliable-with a much lower mass penalty-than solar power for this application. However, recent advances in solar cell and energy storage technologies and changes in operational assumptions prompted NASA to revisit the analysis. For the purpose of this exercise a particular landing site at Jezero Crater, located at 18o north latitude, was assumed. A fission power system consisting of four each 10 kW Kilopower fission reactors was compared to a distributed network of Orion-derived Ultraflex solar arrays and Lithium ion batteries mounted on every lander. The team found that a solar power system mass of about 9,800 kg would provide the 22 kilowatts (kW) keep-alive power needed to survive a dust storm lasting up to 120-days at average optical depth of 5, and 35 kW peak power for normal operations under clear skies. Although this is less than half the mass estimated during the 2007 work (which assumed latitudes up to 30o) it is still more than the 7,000 kg mass of the fission system which provides full power regardless of dust storm conditions.

  9. Energy Theft in the Advanced Metering Infrastructure

    NASA Astrophysics Data System (ADS)

    McLaughlin, Stephen; Podkuiko, Dmitry; McDaniel, Patrick

    Global energy generation and delivery systems are transitioning to a new computerized "smart grid". One of the principle components of the smart grid is an advanced metering infrastructure (AMI). AMI replaces the analog meters with computerized systems that report usage over digital communication interfaces, e.g., phone lines. However, with this infrastructure comes new risk. In this paper, we consider adversary means of defrauding the electrical grid by manipulating AMI systems. We document the methods adversaries will use to attempt to manipulate energy usage data, and validate the viability of these attacks by performing penetration testing on commodity devices. Through these activities, we demonstrate that not only is theft still possible in AMI systems, but that current AMI devices introduce a myriad of new vectors for achieving it.

  10. A threshold for dissipative fission

    SciTech Connect

    Thoennessen, M.; Bertsch, G.F.

    1993-09-21

    The empirical domain of validity of statistical theory is examined as applied to fission data on pre-fission data on pre-fission neutron, charged particle, and {gamma}-ray multiplicities. Systematics are found of 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 T{sub thresh} to the (temperature-dependent) fission barrier height E{sub Bar}(T). The statistical model reproduces the data for T{sub thresh}/E{sub Bar}(T) < 0.26 {plus_minus} 0.05, but underpredicts the multiplicities at higher T{sub thresh}/E{sub Bar}(T) independent of mass and fissility of the systems.

  11. Advanced energy projects FY 1997 research summaries

    SciTech Connect

    1997-09-01

    The mission of the Advanced Energy Projects (AEP) program is to explore the scientific feasibility of novel energy-related concepts that are high risk, in terms of scientific feasibility, yet have a realistic potential for a high technological payoff. The concepts supported by the AEP are typically at an early stage of scientific development. They often arise from advances in basic research and are premature for consideration by applied research or technology development programs. Some are based on discoveries of new scientific phenomena or involve exploratory ideas that span multiple scientific and technical disciplines which do not fit into an existing DOE program area. In all cases, the objective is to support evaluation of the scientific or technical feasibility of the novel concepts involved. Following AEP support, it is expected that each concept will be sufficiently developed to attract further funding from other sources to realize its full potential. Projects that involve evolutionary research or technology development and demonstration are not supported by AEP. Furthermore, research projects more appropriate for another existing DOE research program are not encouraged. There were 65 projects in the AEP research portfolio during Fiscal Year 1997. Eigheen projects were initiated during that fiscal year. This document consists of short summaries of projects active in FY 1997. Further information of a specific project may be obtained by contacting the principal investigator.

  12. The Microscopic Theory of Fission

    SciTech Connect

    Younes, W; Gogny, D

    2009-06-09

    Fission-fragment properties have been calculated for thermal neutron-induced fission on a {sup 239}Pu target, using constrained Hartree-Fock-Bogoliubov calculations with a finite-range effective interaction. A quantitative criterion based on the interaction energy between the nascent fragments is introduced to define the scission configurations. The validity of this criterion is benchmarked against experimental measurements of the kinetic energies and of multiplicities of neutrons emitted by the fragments.

  13. Neutron emission effects on fragment mass and kinetic energy distribution from fission of 239{sup Pu} induced by thermal neutrons

    SciTech Connect

    Montoya, M.; Rojas, J.; Lobato, I.

    2010-08-04

    The average of fragment kinetic energy (E-bar sign*) and the multiplicity of prompt neutrons ({nu}(bar sign)) as a function of fragment mass (m*), as well as the fragment mass yield (Y(m*)) from thermal neutron-induced fission of {sup 239}Pu have been measured by Tsuchiya et al.. In that work the mass and kinetic energy are calculated from the measured kinetic energy of one fragment and the difference of time of flight of the two complementary fragments. However they do not present their results about the standard deviation {sigma}{sub E}*(m*). In this work we have made a numerical simulation of that experiment which reproduces its results, assuming an initial distribution of the primary fragment kinetic energy (E(A)) with a constant value of the standard deviation as function of fragment mass ({sigma}{sub E}(A)). As a result of the simulation we obtain the dependence {sigma}{sub E}*(m*) which presents an enhancement between m* = 92 and m* = 110, and a peak at m* = 121.

  14. Advanced energy storage for space applications: A follow-up

    NASA Technical Reports Server (NTRS)

    Halpert, Gerald; Surampudi, Subbarao

    1994-01-01

    Viewgraphs on advanced energy storage for space applications are presented. Topics covered include: categories of space missions using batteries; battery challenges; properties of SOA and advanced primary batteries; lithium primary cell applications; advanced rechargeable battery applications; present limitations of advanced battery technologies; and status of Li-TiS2, Ni-MH, and Na-NiCl2 cell technologies.

  15. Fission modelling with FIFRELIN

    NASA Astrophysics Data System (ADS)

    Litaize, Olivier; Serot, Olivier; Berge, Léonie

    2015-12-01

    The nuclear fission process gives rise to the formation of fission fragments and emission of particles (n,γ , e-) . The particle emission from fragments can be prompt and delayed. We present here the methods used in the FIFRELIN code, which simulates the prompt component of the de-excitation process. The methods are based on phenomenological models associated with macroscopic and/or microscopic ingredients. Input data can be provided by experiment as well as by theory. The fission fragment de-excitation can be performed within Weisskopf (uncoupled neutron and gamma emission) or a Hauser-Feshbach (coupled neutron/gamma emission) statistical theory. We usually consider five free parameters that cannot be provided by theory or experiments in order to describe the initial distributions required by the code. In a first step this set of parameters is chosen to reproduce a very limited set of target observables. In a second step we can increase the statistics to predict all other fission observables such as prompt neutron, gamma and conversion electron spectra but also their distributions as a function of any kind of parameters such as, for instance, the neutron, gamma and electron number distributions, the average prompt neutron multiplicity as a function of fission fragment mass, charge or kinetic energy, and so on. Several results related to different fissioning systems are presented in this work. The goal in the next decade will be i) to replace some macroscopic ingredients or phenomenological models by microscopic calculations when available and reliable, ii) to be a support for experimentalists in the design of detection systems or in the prediction of necessary beam time or count rates with associated statistics when measuring fragments and emitted particle in coincidence iii) extend the model to be able to run a calculation when no experimental input data are available, iv) account for multiple chance fission and gamma emission before fission, v) account for the

  16. Fission meter

    DOEpatents

    Rowland, Mark S.; Snyderman, Neal J.

    2012-04-10

    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.

  17. Space Fission Propulsion System Development Status

    NASA Technical Reports Server (NTRS)

    Houts, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Williams, Eric; Harper, Roger; Salvail, Pat; Hrbud, Ivana; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    The world's first man-made self-sustaining fission reaction was achieved in 1942. Since then fission has been used to propel submarines, generate tremendous amounts of electricity, produce medical isotopes, and provide numerous other benefits to society. Fission systems operate independently of solar proximity or orientation, and are thus well suited for deep spare or planetary surface missions. In addition, the fuel for fission systems (enriched uranium) is virtually non-radioactive. The primary safety issue with fission systems is avoiding inadvertent system start - addressing this issue through proper system design is straightforward. Despite the relative simplicity and tremendous potential of space fission systems, the development and utilization of these systems has proven elusive. The first use of fission technology in space occurred 3 April 1965 with the US launch of the SNAP-10A reactor. There have been no additional US uses of space fission system. While space fission system were used extensively by the former Soviet Union, their application was limited to earth-orbital missions. Early space fission systems must be safely and affordably utilized if Ae are to reap the benefits of advanced space fission systems.

  18. Fifty years with nuclear fission

    SciTech Connect

    Behrens, J.W.; Carlson, A.D. )

    1989-01-01

    The news of the discovery of nuclear fission, by Otto Hahn and Fritz Strassmann in Germany, was brought to the United States by Niels Bohr in January 1939. Since its discovery, the United States, and the world for that matter, has never been the same. It therefore seemed appropriate to acknowledge the fifieth anniversary of its discovery by holding a topical meeting entitled, Fifty Years with Nuclear Fission,'' in the United States during the year 1989. The objective of the meeting was to bring together pioneers of the nuclear industry and other scientists and engineers to report on reminiscences of the past and on the more recent development in fission science and technology. The conference highlighted the early pioneers of the nuclear industry by dedicated a full day (April 26), consisting of two plenary sessions, at the National Academy of Sciences (NAS) in Washington, DC. More recent developments in fission science and technology in addition to historical reflections were topics for two fully days of sessions (April 27 and 28) at the main site of the NIST in Gaithersburg, Maryland. The wide range of topics covered in this Volume 1 by this topical meeting included plenary invited, and contributed sessions entitled: Preclude to the First Chain Reaction -- 1932 to 1942; Early Fission Research -- Nuclear Structure and Spontaneous Fission; 50 Years of Fission, Science, and Technology; Nuclear Reactors, Secure Energy for the Future; Reactors 1; Fission Science 1; Safeguards and Space Applications; Fission Data; Nuclear Fission -- Its Various Aspects; Theory and Experiments in Support of Theory; Reactors and Safeguards; and General Research, Instrumentation, and By-Product. The individual papers have been cataloged separately.

  19. Cluster aspects of binary fission

    NASA Astrophysics Data System (ADS)

    Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.

    2013-04-01

    With the improved scission-point model the mass distributions are calculated for induced fission of different Hg isotopes with even mass numbers A =180, 184, 188, 192, 196, 198. The calculated mass distribution and mean total kinetic energy of fission fragments are in a good agreement with the existing experimental data. The change in the shape of the mass distribution from asymmetric to more symmetric is revealed with increasing A of the fissioning AHg nucleus, and the reactions are proposed to verify this prediction experimentally.

  20. Distributed sensor coordination for advanced energy systems

    SciTech Connect

    Tumer, Kagan

    2015-03-12

    Motivation: The ability to collect key system level information is critical to the safe, efficient and reliable operation of advanced power systems. Recent advances in sensor technology have enabled some level of decision making directly at the sensor level. However, coordinating large numbers of sensors, particularly heterogeneous sensors, to achieve system level objectives such as predicting plant efficiency, reducing downtime or predicting outages requires sophisticated coordination algorithms. Indeed, a critical issue in such systems is how to ensure the interaction of a large number of heterogenous system components do not interfere with one another and lead to undesirable behavior. Objectives and Contributions: The long-term objective of this work is to provide sensor deployment, coordination and networking algorithms for large numbers of sensors to ensure the safe, reliable, and robust operation of advanced energy systems. Our two specific objectives are to: 1. Derive sensor performance metrics for heterogeneous sensor networks. 2. Demonstrate effectiveness, scalability and reconfigurability of heterogeneous sensor network in advanced power systems. The key technical contribution of this work is to push the coordination step to the design of the objective functions of the sensors, allowing networks of heterogeneous sensors to be controlled. By ensuring that the control and coordination is not specific to particular sensor hardware, this approach enables the design and operation of large heterogeneous sensor networks. In addition to the coordination coordination mechanism, this approach allows the system to be reconfigured in response to changing needs (e.g., sudden external events requiring new responses) or changing sensor network characteristics (e.g., sudden changes to plant condition). Impact: The impact of this work extends to a large class of problems relevant to the National Energy Technology Laboratory including sensor placement, heterogeneous sensor

  1. Nuclear Power from Fission Reactors. An Introduction.

    ERIC Educational Resources Information Center

    Department of Energy, Washington, DC. Technical Information Center.

    The purpose of this booklet is to provide a basic understanding of nuclear fission energy and different fission reaction concepts. Topics discussed are: energy use and production, current uses of fuels, oil and gas consumption, alternative energy sources, fossil fuel plants, nuclear plants, boiling water and pressurized water reactors, the light…

  2. Two neutron correlations in photo-fission

    NASA Astrophysics Data System (ADS)

    Dale, D. S.; Kosinov, O.; Forest, T.; Burggraf, J.; Stave, S.; Warren, G.; Starovoitova, V.

    2016-09-01

    A large body of experimental work has established the strong kinematical correlation between fission fragments and fission neutrons. Here, we report on the progress of investigations of the potential for strong two neutron correlations arising from the nearly back-to-back nature of the two fission fragments that emit these neutrons in the photo-fission process. In initial measurements, a pulsed electron linear accelerator was used to generate bremsstrahlung photons that impinged upon an actinide target, and the energy and opening angle distributions of coincident neutrons were measured using a large acceptance neutron detector array. A planned comprehensive set of measurements of two neutron correlations in the photo-fission of actinides is expected to shed light on several fundamental aspects of the fission process including the multiplicity distributions associated with the light and heavy fission fragments, the nuclear temperatures of the fission fragments, and the mass distribution of the fission fragments as a function of energy released. In addition to these measurements providing important nuclear data, the unique kinematics of fission and the resulting two neutron correlations have the potential to be the basis for a new tool to detect fissionable materials. A key technical challenge of this program arises from the need to perform coincidence measurements with a low duty factor, pulsed electron accelerator. This has motivated the construction of a large acceptance neutron detector array, and the development of data analysis techniques to directly measure uncorrelated two neutron backgrounds.

  3. Prompt Fission Neutron Emission in Resonance Fission of 239Pu

    SciTech Connect

    Hambsch, Franz-Josef; Oberstedt, Stephan; Varapai, Natallia; Serot, Olivier

    2005-05-24

    The prompt neutron emission probability from neutron-induced fission in the resonance region is being investigated at the time-of-flight facility GELINA of the IRMM. A double Frisch-gridded ionization chamber is used as a fission-fragment detector. For the data acquisition of both the fission-fragment signals as well as the neutron detector signals the fast digitization technique has been applied. For the neutron detection, large-volume liquid scintillation detectors from the DEMON collaboration are used. A specialized data analysis program taking advantage of the digital filtering technique has been developed to treat the acquired data.Neutron multiplicity investigations for actinides, especially in resonance neutron-induced fission, are rather scarce. They are, however, important for reactor control and safety issues as well as for understanding the basic physics of the fission process. Fission yield measurements on both 235U and 239Pu without prompt neutron emission coincidence have shown that fluctuation of the fission-fragment mass distribution exists from resonance to resonance, larger in the case of 235U. To possibly explain these observations, the question now is whether the prompt neutron multiplicity shows similar fluctuations with resonance energy.

  4. GGA+U study of uranium mononitride: A comparison of the U-ramping and occupation matrix schemes and incorporation energies of fission products

    NASA Astrophysics Data System (ADS)

    Claisse, Antoine; Klipfel, Marco; Lindbom, Niclas; Freyss, Michel; Olsson, Pär

    2016-09-01

    Uranium mononitride is studied in the DFT + U framework. Its ground state is investigated and a study of the incorporation of diverse fission products in the crystal is conducted. The U-ramping and occupation matrix control (OMC) schemes are used to eliminate metastable states. Beyond a certain amount of introduced correlation, the OMC scheme starts to find a lower total energy. The OMC scheme is chosen for the second part of this study. Furthermore, the influence of the magnetic ordering is studied using the U-ramping method, showing that antiferromagnetic order is the most stable one when the U parameter is larger than 1.75 eV. The effect on the density of states is investigated and elastic constants are provided for comparison with other methods and experiments. The incorporation energies of fission products in different defect configurations are calculated and these energies are corrected to take into account the limited size of the supercell.

  5. Fission Matrix Capability for MCNP Monte Carlo

    SciTech Connect

    Carney, Sean E.; Brown, Forrest B.; Kiedrowski, Brian C.; Martin, William R.

    2012-09-05

    In a Monte Carlo criticality calculation, before the tallying of quantities can begin, a converged fission source (the fundamental eigenvector of the fission kernel) is required. Tallies of interest may include powers, absorption rates, leakage rates, or the multiplication factor (the fundamental eigenvalue of the fission kernel, k{sub eff}). Just as in the power iteration method of linear algebra, if the dominance ratio (the ratio of the first and zeroth eigenvalues) is high, many iterations of neutron history simulations are required to isolate the fundamental mode of the problem. Optically large systems have large dominance ratios, and systems containing poor neutron communication between regions are also slow to converge. The fission matrix method, implemented into MCNP[1], addresses these problems. When Monte Carlo random walk from a source is executed, the fission kernel is stochastically applied to the source. Random numbers are used for: distances to collision, reaction types, scattering physics, fission reactions, etc. This method is used because the fission kernel is a complex, 7-dimensional operator that is not explicitly known. Deterministic methods use approximations/discretization in energy, space, and direction to the kernel. Consequently, they are faster. Monte Carlo directly simulates the physics, which necessitates the use of random sampling. Because of this statistical noise, common convergence acceleration methods used in deterministic methods do not work. In the fission matrix method, we are using the random walk information not only to build the next-iteration fission source, but also a spatially-averaged fission kernel. Just like in deterministic methods, this involves approximation and discretization. The approximation is the tallying of the spatially-discretized fission kernel with an incorrect fission source. We address this by making the spatial mesh fine enough that this error is negligible. As a consequence of discretization we get a

  6. Advanced Energy Efficiency and Distributed Renewables

    NASA Astrophysics Data System (ADS)

    Lovins, Amory

    2007-04-01

    The US now wrings twice the GDP from each unit of energy that it did in 1975. Reduced energy intensity since then now provides more than twice as much service as burning oil does. Yet still more efficient end-use of energy -- explained more fully in a companion workshop offered at 1245 -- is the largest, fastest, cheapest, most benign, least understood, and least harnessed energy resource available. For example, existing technologies could save half of 2000 US oil and gas and three-fourths of US electricity, at lower cost than producing and delivering that energy from existing facilities. Saving half the oil through efficiency and replacing the other half with saved natural gas and advanced biofuels would cost an average of only 15/barrel and could eliminate US oil use by the 2040s, led by business for profit. Efficiency techniques and ways to combine and apply them continue to improve faster than they're applied, so the ``efficiency resource'' is becoming ever larger and cheaper. As for electricity, ``micropower'' (distributed renewables plus low-carbon cogeneration) is growing so quickly that by 2005 it provided a sixth of the world's electricity and a third of its new electricity, and was adding annually 4x the capacity and 11x the capacity added by nuclear power, which it surpassed in capacity in 2002 and in output in 2006. Together, micropower and ``negawatts'' (saved electricity) now provide upwards half the world's new electrical services, due to their far lower cost and lower financial risk than the central thermal power stations that still dominate policy discussions. For oil and electricity, each of which adds about two-fifths of the world's energy-related carbon dioxide emissions, efficiency plus competitive alternative supplies can stabilize the earth's climate at a profit, as well as solving the oil and (largely) the nuclear proliferation problems. Conversely, costlier and slower options, notably nuclear power, would displace less carbon emission per

  7. Fission of rotating fermium isotopes

    NASA Astrophysics Data System (ADS)

    Baran, A.; Staszczak, A.

    2014-05-01

    In this paper we discuss the process of fission of even fermium isotopes, on the basis of their rotational states. The nuclear intrinsic vorticity and its coupling to the global rotation of the nucleus are used to simulate the interaction between the rotational motion and the pairing field, and lead to pairing quenching in the case of higher angular momentum states. The rotation leads to a decreasing of the fission barrier heights. The ingredients of the model—ground state fission barriers, pairing correlation energies and the cranking moments of inertia—are obtained within the self-consistent Hartree-Fock-Bogoliubov framework using the Skyrme \\text{Sk}{{\\text{M}}^{*}} energy density functional. Fission barriers and half-lives are estimated for spins I up to I = 16ℏ.

  8. Theoretical Description of the Fission Process

    SciTech Connect

    Witold Nazarewicz

    2003-07-01

    The main goals of the project can be summarized as follows: Development of effective energy functionals that are appropriate for the description of heavy nuclei. Our goal is to improve the existing energy density (Skyrme) functionals to develop a force that will be used in calculations of fission dynamics. Systematic self-consistent calculations of binding energies and fission barriers of actinide and trans-actinide nuclei using modern density functionals. This will be followed by calculations of spontaneous fission lifetimes and mass and charge divisions using dynamic adiabatic approaches based on the WKB approximation. Investigate novel microscopic (non-adiabatic) methods to study the fission process.

  9. Results of a First Generation Propellant Energy Source Module Testing: Non-Nuclear Testing of Fission System

    NASA Technical Reports Server (NTRS)

    VanDyke, Melissa; Godfroy, Tom; Houts, Mike; Dickens, Ricky; Dobson, Chris; Pederson, Kevin; Reid, Bob

    1999-01-01

    The use of resistance heaters to simulate heat from fission allows extensive development of fission systems to be performed in non-nuclear test facilities, saving time and money. Resistance heated tests on the Module Unfueled Thermal- hydraulic Test (MUTT) article has been performed at the Marshall Space Flight Center. This paper discusses the results of these experiments to date, and describes the additional testing that will be performed. Recommendations related to the design of testable space fission power and propulsion systems are made.

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

    DOEpatents

    Norman, Eric B [Oakland, CA; Prussin, Stanley G [Kensington, CA

    2009-05-05

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

    DOEpatents

    Norman, Eric B.; Prussin, Stanley G.

    2009-01-27

    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.

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

    DOEpatents

    Norman, Eric B.; Prussin, Stanley G.

    2009-01-06

    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.

  13. Distributed Sensor Coordination for Advanced Energy Systems

    SciTech Connect

    Tumer, Kagan

    2013-07-31

    The ability to collect key system level information is critical to the safe, efficient and reli- able operation of advanced energy systems. With recent advances in sensor development, it is now possible to push some level of decision making directly to computationally sophisticated sensors, rather than wait for data to arrive to a massive centralized location before a decision is made. This type of approach relies on networked sensors (called “agents” from here on) to actively collect and process data, and provide key control deci- sions to significantly improve both the quality/relevance of the collected data and the as- sociating decision making. The technological bottlenecks for such sensor networks stem from a lack of mathematics and algorithms to manage the systems, rather than difficulties associated with building and deploying them. Indeed, traditional sensor coordination strategies do not provide adequate solutions for this problem. Passive data collection methods (e.g., large sensor webs) can scale to large systems, but are generally not suited to highly dynamic environments, such as ad- vanced energy systems, where crucial decisions may need to be reached quickly and lo- cally. Approaches based on local decisions on the other hand cannot guarantee that each agent performing its task (maximize an agent objective) will lead to good network wide solution (maximize a network objective) without invoking cumbersome coordination rou- tines. There is currently a lack of algorithms that will enable self-organization and blend the efficiency of local decision making with the system level guarantees of global decision making, particularly when the systems operate in dynamic and stochastic environments. In this work we addressed this critical gap and provided a comprehensive solution to the problem of sensor coordination to ensure the safe, reliable, and robust operation of advanced energy systems. The differentiating aspect of the proposed work is in shift- ing

  14. Development of High-Temperature Ferritic Alloys and Performance Prediction Methods for Advanced Fission Energy Systems

    SciTech Connect

    G. RObert Odette; Takuya Yamamoto

    2009-08-14

    Reports the results of a comprehensive development and analysis of a database on irradiation hardening and embrittlement of tempered martensitic steels (TMS). Alloy specific quantitative semi-empirical models were derived for the dpa dose, irradiation temperature (ti) and test (Tt) temperature of yield stress hardening (or softening) .

  15. Energy Dependence of Fission Product Yields from 235U, 238U and 239Pu for Incident Neutron Energies Between 0.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; Kelley, J. H.; Krishichayan; Macri, R.; Rusev, G.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2016-01-01

    Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varying degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual-fission chamber and gamma

  16. Energy dependence of fission product yields from 235U, 238U and 239Pu for incident neutron energies between 0.5 and 14.8 MeV

    DOE PAGES

    Gooden, M. E.; Arnold, C. W.; Becker, J. A.; Bhatia, C.; Bhike, M.; Bond, E. M.; Bredeweg, T. A.; Fallin, B.; Fowler, M. M.; Howell, C. R.; et al

    2016-01-06

    In this study, Fission Product Yields (FPY) have historically been one of the most observable features of the fission process. They are known to have strong variations that are dependent on the fissioning species, the excitation energy, and the angular momentum of the compound system. However, consistent and systematic studies of the variation of these FPY with energy have proved challenging. This is caused primarily by the nature of the experiments that have traditionally relied on radiochemical procedures to isolate specific fission products. Although radiochemical procedures exist that can isolate all products, each element presents specific challenges and introduces varyingmore » degrees of systematic errors that can make inter-comparison of FPY uncertain. Although of high importance in fields such as nuclear forensics and Stockpile Stewardship, accurate information about the energy dependence of neutron induced FPY are sparse, due primarily to the lack of suitable monoenergetic neutron sources. There is a clear need for improved data, and to address this issue, a collaboration was formed between Los Alamos National Laboratory (LANL), Lawrence Livermore National Laboratory (LLNL) and the Triangle Universities Nuclear Laboratory (TUNL) to measure the energy dependence of FPY for 235U, 238U and 239Pu. The measurements have been performed at TUNL, using a 10 MV Tandem Van de Graaff accelerator to produce monoenergetic neutrons at energies between 0.6 MeV to 14.8 MeV through a variety of reactions. The measurements have utilized a dual-fission chamber, with thin (10-100 μg/cm2) reference foils of similar material to a thick (100-400 mg) activation target held in the center between the chambers. This method allows for the accurate determination of the number of fissions that occurred in the thick target without requiring knowledge of the fission cross section or neutron fluence on target. Following activation, the thick target was removed from the dual-fission

  17. Advancement of DOE's EnergyPlus Building Energy Simulation Payment

    SciTech Connect

    Gu, Lixing; Shirey, Don; Raustad, Richard; Nigusse, Bereket; Sharma, Chandan; Lawrie, Linda; Strand, Rick; Pedersen, Curt; Fisher, Dan; Lee, Edwin; Witte, Mike; Glazer, Jason; Barnaby, Chip

    2011-09-30

    EnergyPlus{sup TM} is a new generation computer software analysis tool that has been developed, tested, and commercialized to support DOE's Building Technologies (BT) Program in terms of whole-building, component, and systems R&D (http://www.energyplus.gov). It is also being used to support evaluation and decision making of zero energy building (ZEB) energy efficiency and supply technologies during new building design and existing building retrofits. The 5-year project was managed by the National Energy Technology Laboratory and was divided into 5 budget period between 2006 and 2011. During the project period, 11 versions of EnergyPlus were released. This report summarizes work performed by an EnergyPlus development team led by the University of Central Florida's Florida Solar Energy Center (UCF/FSEC). The team members consist of DHL Consulting, C. O. Pedersen Associates, University of Illinois at Urbana-Champaign, Oklahoma State University, GARD Analytics, Inc., and WrightSoft Corporation. The project tasks involved new feature development, testing and validation, user support and training, and general EnergyPlus support. The team developed 146 new features during the 5-year period to advance the EnergyPlus capabilities. Annual contributions of new features are 7 in budget period 1, 19 in period 2, 36 in period 3, 41 in period 4, and 43 in period 5, respectively. The testing and validation task focused on running test suite and publishing report, developing new IEA test suite cases, testing and validating new source code, addressing change requests, and creating and testing installation package. The user support and training task provided support for users and interface developers, and organized and taught workshops. The general support task involved upgrading StarTeam (team sharing) software and updating existing utility software. The project met the DOE objectives and completed all tasks successfully. Although the EnergyPlus software was enhanced significantly

  18. Advanced component technologies for energy-efficient turbofan engines

    NASA Technical Reports Server (NTRS)

    Saunders, N. T.

    1980-01-01

    A cooperative government-industry effort, the Energy Efficient Engine Project, to develop the advanced technology base for future commercial development of a new generation of more fuel conservative turbofan engines for airline use is described. Engine configurations that are dependent upon technology advances in each major engine component are defined and current design and development of the advanced components are included.

  19. Options For Development of Space Fission Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Houta, Mike; VanDyke, Melissa; Godfroy, Tom; Pedersen, Kevin; Martin, James; Dickens, Ricky; Salvail, Pat; Hrbud, Ivana; Rodgers, Stephen L. (Technical Monitor)

    2001-01-01

    Fission technology can enable rapid, affordable access to any point in the solar system. Potential fission-based transportation options include high specific power continuous impulse propulsion systems and bimodal nuclear thermal rockets. Despite their tremendous potential for enhancing or enabling deep space and planetary missions, to date space fission system have only been used in Earth orbit. The first step towards utilizing advanced fission propulsion systems is development of a safe, near-term, affordable fission system that can enhance or enable near-term missions of interest. An evolutionary approach for developing space fission propulsion systems is proposed.

  20. Two-Dimensional Mapping of the Calculated Fission Power for the Full-Size Fuel Plate Experiment Irradiated in the Advanced Test Reactor

    NASA Astrophysics Data System (ADS)

    Chang, G. S.; Lillo, M. A.

    2009-08-01

    The National Nuclear Security Administrations (NNSA) Reduced Enrichment for Research and Test Reactors (RERTR) program assigned to the Idaho National Laboratory (INL) the responsibility of developing and demonstrating high uranium density research reactor fuel forms to enable the use of low enriched uranium (LEU) in research and test reactors around the world. A series of full-size fuel plate experiments have been proposed for irradiation testing in the center flux trap (CFT) position of the Advanced Test Reactor (ATR). These full-size fuel plate tests are designated as the AFIP tests. The AFIP nominal fuel zone is rectangular in shape having a designed length of 21.5-in (54.61-cm), width of 1.6-in (4.064-cm), and uniform thickness of 0.014-in (0.03556-cm). This gives a nominal fuel zone volume of 0.482 in3 (7.89 cm3) per fuel plate. The AFIP test assembly has two test positions. Each test position is designed to hold 2 full-size plates, for a total of 4 full-size plates per test assembly. The AFIP test plates will be irradiated at a peak surface heat flux of about 350 W/cm2 and discharged at a peak U-235 burn-up of about 70 at.%. Based on limited irradiation testing of the monolithic (U-10Mo) fuel form, it is desirable to keep the peak fuel temperature below 250°C to achieve this, it will be necessary to keep plate heat fluxes below 500 W/cm2. Due to the heavy U-235 loading and a plate width of 1.6-in (4.064-cm), the neutron self-shielding will increase the local-to-average-ratio (L2AR) fission power near the sides of the fuel plates. To demonstrate that the AFIP experiment will meet the ATR safety requirements, a very detailed 2-dimensional (2D) Y-Z fission power profile was evaluated in order to best predict the fuel plate temperature distribution. The ability to accurately predict fuel plate power and burnup are essential to both the design of the AFIP tests as well as evaluation of the irradiated fuel performance. To support this need, a detailed MCNP Y

  1. Neutron Emission in Fission and Quasi-Fission

    NASA Astrophysics Data System (ADS)

    Itkis, I.; Bogatchev, A. A.; Chizhov, A. Yu.; Itkis, M. G.; Kliman, J.; Knyazheva, G. N.; Kondratiev, N. A.; Kozulin, E. M.; Korzyukov, I. V.; Krupa, L.; Oganessian, Yu. Ts.; Pokrovski, I. V.; Prokhorova, E. V.; Sagaidak, R. N.; Voskressenski, V. M.; Rusanov, A. Ya.; Corradi, L.; Stefanini, A. M.; Trotta, M.; Beghini, S.; Montagnoli, G.; Scarlassara, F.; Chubarian, G.; Hanappe, F.; Materna, T.; Dorvaux, O.; Rowley, N.; Stuttge, L.; Giardina, G.

    2005-09-01

    The work presents the results of the study of characteristics of the neutron emission in fission and quasi-fission of heavy and super-heavy nuclei, produced in the reactions with heavy ions. These experiments have been performed at the U-400 accelerator of the Flerov Laboratory of Nuclear Reactions (JINR), tandem accelerator in Legnaro (LNL) and VIVITRON accelerator in Strasbourg (IReS) with the use of the time-of-flight spectrometer of fission fragments CORSET and neutron multidetector DEMON. Mass-energy distributions (MED) of the 48Ca + 168Er, 208Pb, 238U and 18O + 208Pb reactions products at energies close to and below the Coulomb barrier have been studied. The pre- and post-fission neutron multiplicities as a function of the fragment mass have been obtained. A significant yield of the asymmetric component observed in the fragment mass distributions in the case of 18O + 208Pb reaction denotes the multimodal nature of the fission process. At the same time an increase in the yield of fragment masses ML ≅ 75-85 and MH ≅ 200-210 in the case 48Ca+208Pb, 238U reactions and ML ≅ 75-85 and MH ≅ 130-140 in the case 48Ca+168Er is rather connected with a quasi-fission process. The obtained neutron multiplicities dependences on fragment masses showed the validity of these assumptions.

  2. Fission Modes of Mercury Isotopes

    SciTech Connect

    Warda, M.; Staszczak, A.; Nazarewicz, Witold

    2012-01-01

    Background: Recent experiments on -delayed fission in the mercury-lead region and the discovery of asymmetric fission in 180Hg [A. N. Andreyev et al., Phys. Rev. Lett. 105, 252502 (2010)] have stimulated theoretical interest in the mechanism of fission in heavy nuclei.

    Purpose: We study fission modes and fusion valleys in 180Hg and 198Hg to reveal the role of shell effects in the prescission region and explain the experimentally observed fragment mass asymmetry and its variation with A.

    Methods: We use the self-consistent nuclear density functional theory employing Skyrme and Gogny energy density functionals.

    Results: The potential energy surfaces in multidimensional space of collective coordinates, including elongation, triaxiality, reflection-asymmetry, and necking, are calculated for 180Hg and 198Hg. The asymmetric fission valleys well separated from fusion valleys associated with nearly spherical fragments are found in both cases. The density distributions at scission configurations are studied and related to the experimentally observed mass splits.

    Conclusions: The energy density functionals SkM and D1S give a very consistent description of the fission process in 180Hg and 198Hg. We predict a transition from asymmetric fission in 180Hg toward a more symmetric distribution of fission fragments in 198Hg. For 180Hg, both models yield 100Ru/80Kr as the most probable split. For 198Hg, the most likely split is 108Ru/90Kr in HFB-D1S and 110Ru/88Kr in HFB-SkM .

  3. Highly efficient spin-conversion effect leading to energy up-converted electroluminescence in singlet fission photovoltaics

    NASA Astrophysics Data System (ADS)

    Pandey, Ajay K.

    2015-01-01

    Free charge generation in donor-acceptor (D-A) based organic photovoltaic diodes (OPV) progresses through formation of charge-transfer (CT) and charge-separated (CS) states and excitation decay to the triplet level is considered as a terminal loss. On the other hand a direct excitation decay to the triplet state is beneficial for multiexciton harvesting in singlet fission photovoltaics (SF-PV) and the formation of CT-state is considered as a limiting factor for multiple triplet harvesting. These two extremes when present in a D-A system are expected to provide important insights into the mechanism of free charge generation and spin-character of bimolecular recombination in OPVs. Herein, we present the complete cycle of events linked to spin conversion in the model OPV system of rubrene/C60. By tracking the spectral evolution of photocurrent generation at short-circuit and close to open-circuit conditions we are able to capture spectral changes to photocurrent that reveal the triplet character of CT-state. Furthermore, we unveil an energy up-conversion effect that sets in as a consequence of triplet population build-up where triplet-triplet annihilation (TTA) process effectively regenerates the singlet excitation. This detailed balance is shown to enable a rare event of photon emission just above the open-circuit voltage (VOC) in OPVs.

  4. Highly efficient spin-conversion effect leading to energy up-converted electroluminescence in singlet fission photovoltaics.

    PubMed

    Pandey, Ajay K

    2015-01-01

    Free charge generation in donor-acceptor (D-A) based organic photovoltaic diodes (OPV) progresses through formation of charge-transfer (CT) and charge-separated (CS) states and excitation decay to the triplet level is considered as a terminal loss. On the other hand a direct excitation decay to the triplet state is beneficial for multiexciton harvesting in singlet fission photovoltaics (SF-PV) and the formation of CT-state is considered as a limiting factor for multiple triplet harvesting. These two extremes when present in a D-A system are expected to provide important insights into the mechanism of free charge generation and spin-character of bimolecular recombination in OPVs. Herein, we present the complete cycle of events linked to spin conversion in the model OPV system of rubrene/C60. By tracking the spectral evolution of photocurrent generation at short-circuit and close to open-circuit conditions we are able to capture spectral changes to photocurrent that reveal the triplet character of CT-state. Furthermore, we unveil an energy up-conversion effect that sets in as a consequence of triplet population build-up where triplet-triplet annihilation (TTA) process effectively regenerates the singlet excitation. This detailed balance is shown to enable a rare event of photon emission just above the open-circuit voltage (V(OC)) in OPVs. PMID:25585937

  5. Highly efficient spin-conversion effect leading to energy up-converted electroluminescence in singlet fission photovoltaics

    PubMed Central

    Pandey, Ajay K.

    2015-01-01

    Free charge generation in donor-acceptor (D-A) based organic photovoltaic diodes (OPV) progresses through formation of charge-transfer (CT) and charge-separated (CS) states and excitation decay to the triplet level is considered as a terminal loss. On the other hand a direct excitation decay to the triplet state is beneficial for multiexciton harvesting in singlet fission photovoltaics (SF-PV) and the formation of CT-state is considered as a limiting factor for multiple triplet harvesting. These two extremes when present in a D-A system are expected to provide important insights into the mechanism of free charge generation and spin-character of bimolecular recombination in OPVs. Herein, we present the complete cycle of events linked to spin conversion in the model OPV system of rubrene/C60. By tracking the spectral evolution of photocurrent generation at short-circuit and close to open-circuit conditions we are able to capture spectral changes to photocurrent that reveal the triplet character of CT-state. Furthermore, we unveil an energy up-conversion effect that sets in as a consequence of triplet population build-up where triplet-triplet annihilation (TTA) process effectively regenerates the singlet excitation. This detailed balance is shown to enable a rare event of photon emission just above the open-circuit voltage (VOC) in OPVs. PMID:25585937

  6. Neutron Emission in Fission And Quasi-Fission of Hs

    SciTech Connect

    Itkis, I. M.; Itkis, M. G.; Knyazheva, G. N.; Kozulin, E. M.; Krupa, L.; Hanappe, F.; Dorvaux, O.; Stuttge, L.

    2010-04-30

    Mass and energy distributions of fission-like fragments obtained in the reactions {sup 26}Mg+{sup 248}Cm, {sup 36}S+{sup 238}U and {sup 58}Fe+{sup 208}Pb leading to the formation of {sup 266,274}Hs are reported. From the analysis of TKE distributions for symmetric fragment it was found that at energies below the Coulomb barrier the bimodal fission of {sup 274}Hs, formed in the reaction {sup 26}Mg+{sup 248}Cm, is observed, while in the reaction {sup 36}S+{sup 238}U at these energies the main part of the symmetric fragments arises from the quasi-fission process. At energies above the Coulomb barrier the fusion-fission is a main process leading to the formation of symmetric fragment for the both reactions. In the case of {sup 58}Fe+{sup 208}Pb reaction the quasi-fission process is the main reaction mechanism at all measured energies. The pre- and post-scission neutron multiplicities as a function of the fragment mass have been obtained for all studied reactions.

  7. Advanced Potential Energy Surfaces for Molecular Simulation.

    PubMed

    Albaugh, Alex; Boateng, Henry A; Bradshaw, Richard T; Demerdash, Omar N; Dziedzic, Jacek; Mao, Yuezhi; Margul, Daniel T; Swails, Jason; Zeng, Qiao; Case, David A; Eastman, Peter; Wang, Lee-Ping; Essex, Jonathan W; Head-Gordon, Martin; Pande, Vijay S; Ponder, Jay W; Shao, Yihan; Skylaris, Chris-Kriton; Todorov, Ilian T; Tuckerman, Mark E; Head-Gordon, Teresa

    2016-09-22

    Advanced potential energy surfaces are defined as theoretical models that explicitly include many-body effects that transcend the standard fixed-charge, pairwise-additive paradigm typically used in molecular simulation. However, several factors relating to their software implementation have precluded their widespread use in condensed-phase simulations: the computational cost of the theoretical models, a paucity of approximate models and algorithmic improvements that can ameliorate their cost, underdeveloped interfaces and limited dissemination in computational code bases that are widely used in the computational chemistry community, and software implementations that have not kept pace with modern high-performance computing (HPC) architectures, such as multicore CPUs and modern graphics processing units (GPUs). In this Feature Article we review recent progress made in these areas, including well-defined polarization approximations and new multipole electrostatic formulations, novel methods for solving the mutual polarization equations and increasing the MD time step, combining linear-scaling electronic structure methods with new QM/MM methods that account for mutual polarization between the two regions, and the greatly improved software deployment of these models and methods onto GPU and CPU hardware platforms. We have now approached an era where multipole-based polarizable force fields can be routinely used to obtain computational results comparable to state-of-the-art density functional theory while reaching sampling statistics that are acceptable when compared to that obtained from simpler fixed partial charge force fields.

  8. Advanced Potential Energy Surfaces for Molecular Simulation.

    PubMed

    Albaugh, Alex; Boateng, Henry A; Bradshaw, Richard T; Demerdash, Omar N; Dziedzic, Jacek; Mao, Yuezhi; Margul, Daniel T; Swails, Jason; Zeng, Qiao; Case, David A; Eastman, Peter; Wang, Lee-Ping; Essex, Jonathan W; Head-Gordon, Martin; Pande, Vijay S; Ponder, Jay W; Shao, Yihan; Skylaris, Chris-Kriton; Todorov, Ilian T; Tuckerman, Mark E; Head-Gordon, Teresa

    2016-09-22

    Advanced potential energy surfaces are defined as theoretical models that explicitly include many-body effects that transcend the standard fixed-charge, pairwise-additive paradigm typically used in molecular simulation. However, several factors relating to their software implementation have precluded their widespread use in condensed-phase simulations: the computational cost of the theoretical models, a paucity of approximate models and algorithmic improvements that can ameliorate their cost, underdeveloped interfaces and limited dissemination in computational code bases that are widely used in the computational chemistry community, and software implementations that have not kept pace with modern high-performance computing (HPC) architectures, such as multicore CPUs and modern graphics processing units (GPUs). In this Feature Article we review recent progress made in these areas, including well-defined polarization approximations and new multipole electrostatic formulations, novel methods for solving the mutual polarization equations and increasing the MD time step, combining linear-scaling electronic structure methods with new QM/MM methods that account for mutual polarization between the two regions, and the greatly improved software deployment of these models and methods onto GPU and CPU hardware platforms. We have now approached an era where multipole-based polarizable force fields can be routinely used to obtain computational results comparable to state-of-the-art density functional theory while reaching sampling statistics that are acceptable when compared to that obtained from simpler fixed partial charge force fields. PMID:27513316

  9. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 5: Conclusions and recomendations

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    Air pollution resulting from the use of fossil fuels is discussed. Phenomena relating to the emission of CO2 such as the greenhouse effect and multiplier effect are explored. Particulate release is also discussed. The following recommendations are made for the elimination of fossil fuel combustion products in the United States: development of nuclear breeder reactors, use of solar energy systems, exploration of energy alternatives such as geothermal and fusion, and the substitution of coal for gas and oil use.

  10. A study of potential high band-gap photovoltaic materials for a two step photon intermediate technique in fission energy conversion. Final report

    SciTech Connect

    Prelas, M.A.

    1996-01-24

    This report describes progress made to develop a high bandgap photovoltaic materials for direct conversion to electricity of excimer radiation produced by fission energy pumped laser. This report summarizes the major achievements in sections. The first section covers n-type diamond. The second section covers forced diffusion. The third section covers radiation effects. The fourth section covers progress in Schottky barrier and heterojunction photovoltaic cells. The fifth section covers cell and reactor development.

  11. Fission cross section uncertainties with the NIFFTE TPC

    NASA Astrophysics Data System (ADS)

    Sangiorgio, Samuele; Niffte Collaboration

    2014-09-01

    Nuclear data such as neutron-induced fission cross sections play a fundamental role in nuclear energy and defense applications. In recent years, understanding of these systems has become increasingly dependent upon advanced simulation and modeling, where uncertainties in nuclear data propagate in the expected performances of existing and future systems. It is important therefore that uncertainties in nuclear data are minimized and fully understood. For this reason, the Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) uses a Time Projection Chamber (TPC) to measure energy-differential (n,f) cross sections with unprecedented precision. The presentation will discuss how the capabilities of the NIFFTE TPC allow to directly measures systematic uncertainties in fission cross sections, in particular for what concerns fission-fragment identification, and target and beam uniformity. Preliminary results from recent analysis of 238U/235U and 239Pu/235U data collected with the TPC will be presented. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  12. Fission-induced plasmas

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Shiu, Y. J.

    1979-01-01

    The possibility of creating a plasma from fission fragments, and to utilize the energy of the particles to create population inversion that would lead to laser action is investigated. An investigation was made of various laser materials which could be used for nuclear-pumped lasing. The most likely candidate for a fissioning material in the gaseous form is uranium hexafluoride - UF6, and experiments were performed to investigate materials that would be compatible with it. One of the central problems in understanding a fission-induced plasma is to obtain a model of the electron behavior, and some preliminary calculations are presented. In particular, the rates of various processes are discussed. A simple intuitive model of the electron energy distribution function is also shown. The results were useful for considering a mathematical model of a nuclear-pumped laser. Next a theoretical model of a (3)He-Ar nuclear-pumped laser is presented. The theory showed good qualitative agreement with the experimental results.

  13. Nuclear Fission and Fission{minus}Product Spectroscopy: Second International Workshop. Proceedings

    SciTech Connect

    Fioni, G.; Faust, H.; Oberstedt, S.; Hambsch, F.

    1998-10-01

    These proceedings represent papers presented at the Second International Workshop on Nuclear Fission and Fission{minus}Product Spectroscopy held in Seyssins, France in April, 1998. The objective was to bring together the specialists in the field to overview the situation and to assess our present understanding of the fission process. The topics presented at the conference included nuclear waste management, incineration, neutron driven transmutation, leakage etc., radioactive beams, neutron{minus}rich nuclei, neutron{minus}induced and spontaneous fission, ternary fission phenomena, angular momentum, parity and time{minus}reversal phenomena, and nuclear fission at higher excitation energy. Modern spectroscopic tools for gamma spectroscopy as applied to fission were also discussed. There were 53 papers presented at the conference,out of which 3 have been abstracted for the Energy,Science and Technology database.(AIP)

  14. Dynamical simulation of energy dissipation in asymmetric heavy-ion induced fission of {sup 200}Pb, {sup 213}Fr, and {sup 251}Es

    SciTech Connect

    Mirfathi, S. M.; Pahlavani, M. R.

    2008-12-15

    The dynamical model based on the asymmetric mass division has been applied to calculate pre-scission neutron multiplicity from heavy-ion induced fusion-fission reactions. Links between the pre-scission neutron multiplicity, excitation energy, and asymmetric mass distribution are clarified based on the Monte Carlo simulation and Langevin dynamics. The pre-scission neutron multiplicity is calculated and compared with the respective experimental data over a wide range of excitation energy and nonconstant viscosity. The analysis indicates a different effect for the application of asymmetric mass division in different energy regions of such processes.

  15. Development and Utilization of Space Fission Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael; Mason, Lee S.; Palac, Donald T.; Harlow, Scott E.

    2008-01-01

    Space fission power systems could enable advanced civilian space missions. Terrestrially, thousands of fission systems have been operated since 1942. In addition, the US flew a space fission system in 1965, and the former Soviet Union flew 33 such systems prior to the end of the Cold War. Modern design and development practices, coupled with 65 years of experience with terrestrial reactors, could enable the affordable development of space fission power systems for near-term planetary surface applications.

  16. Development and Utilization of Space Fission Power Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.; Mason, Lee S.; Palac, Donald T.; Harlow, Scott E.

    2009-01-01

    Space fission power systems could enable advanced civilian space missions. Terrestrially, thousands of fission systems have been operated since 1942. In addition, the US flew a space fission system in 1965, and the former Soviet Union flew 33 such systems prior to the end of the Cold War. Modern design and development practices, coupled with 65 years of experience with terrestrial reactors, could enable the affordable development of space fission power systems for near-term planetary surface applications.

  17. Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program Implementation

    SciTech Connect

    Liby, Alan L; Rogers, Hiram

    2013-10-01

    The goal of this activity was to carry out program implementation and technical projects in support of the ARRA-funded Advanced Materials in Support of EERE Needs to Advance Clean Energy Technologies Program of the DOE Advanced Manufacturing Office (AMO) (formerly the Industrial Technologies Program (ITP)). The work was organized into eight projects in four materials areas: strategic materials, structural materials, energy storage and production materials, and advanced/field/transient processing. Strategic materials included work on titanium, magnesium and carbon fiber. Structural materials included work on alumina forming austentic (AFA) and CF8C-Plus steels. The advanced batteries and production materials projects included work on advanced batteries and photovoltaic devices. Advanced/field/transient processing included work on magnetic field processing. Details of the work in the eight projects are available in the project final reports which have been previously submitted.

  18. Preliminary Results of an On-Line, Multi-Spectrometer Fission Product Monitoring System to Support Advanced Gas Reactor Fuel Testing and Qualification in the Advanced Test Reactor at the Idaho National Laboratory

    SciTech Connect

    Dawn M. Scates; John K. Hartwell; John B. Walter; Mark W. Drigert

    2007-10-01

    The Advanced Gas Reactor -1 (AGR-1) experiment is the first experiment in a series of eight separate low enriched uranium (LEU) oxycarbide (UCO) tri-isotropic (TRISO) particle fuel (in compact form) experiments scheduled for placement in the Advanced Test Reactor (ATR) located at the Idaho National Laboratory (INL). The experiment began irradiation in the ATR with a cycle that reached full power on December 26, 2006 and will continue irradiation for about 2.5 years. During this time six separate capsules, will be irradiated in an inert sweep gas atmosphere with individual on-line fission product monitoring on its effluent to track performance of the fuel in each individual capsule during irradiation. The goals of the irradiation experiment is to provide irradiation performance data to support fuel process development, to qualify fuel for normal operating conditions, to support development and validation of fuel, and to provide irradiated fuel and materials for post irradiation examination (PIE) and safety testing. This paper presents the preliminary test details of the fuel performance, as measured by the control and acquisition software.

  19. A hemi-fission intermediate links two mechanistically distinct stages of membrane fission

    PubMed Central

    Sundborger, Anna C.; Hortelano, Eva Rodriguez; Fuhrmans, Marc; Neumann, Sylvia; Müller, Marcus; Hinshaw, Jenny E.; Schmid, Sandra L.; Frolov, Vadim A.

    2015-01-01

    Fusion and fission drive all vesicular transport. Although topologically opposite, these reactions pass through the same hemi-fusion/fission intermediate1,2, characterized by a ‘stalk’ in which only the inner monolayers of the two compartments have merged to form a localized non-bilayer connection1-3. Formation of the hemi-fission intermediate requires energy input from proteins catalyzing membrane remodeling; however the relationship between protein conformational rearrangements and hemi-fusion/fission remains obscure. Here we analyzed how the GTPase cycle of dynamin, the prototypical membrane fission catalyst4-6, is directly coupled to membrane remodeling. We used intra-molecular chemical cross-linking to stabilize dynamin in its GDP•AlF4--bound transition-state. In the absence of GTP this conformer produced stable hemi-fission, but failed to progress to complete fission, even in the presence of GTP. Further analysis revealed that the pleckstrin homology domain (PHD) locked in its membrane-inserted state facilitated hemi-fission. A second mode of dynamin activity, fueled by GTP hydrolysis, couples dynamin disassembly with cooperative diminishing of the PHD wedging, thus destabilizing the hemi-fission intermediate to complete fission. Molecular simulations corroborate the bimodal character of dynamin action and indicate radial and axial forces as dominant, although not independent drivers of hemi-fission and fission transformations, respectively. Mirrored in the fusion reaction7-8, the force bimodality might constitute a general paradigm for leakage-free membrane remodeling. PMID:26123023

  20. The SOFIA experiment: Measurement of 236U fission fragment yields in inverse kinematics

    NASA Astrophysics Data System (ADS)

    Grente, L.; Taïeb, J.; Chatillon, A.; Martin, J.-F.; Pellereau, É.; Boutoux, G.; Gorbinet, T.; Bélier, G.; Laurent, B.; Alvarez-Pol, H.; Ayyad, Y.; Benlliure, J.; Caamaño, M.; Audouin, L.; Casarejos, E.; Cortina-Gil, D.; Farget, F.; Fernández-Domínguez, B.; Heinz, A.; Jurado, B.; Kelić-Heil, A.; Kurz, N.; Lindberg, S.; Löher, B.; Nociforo, C.; Paradela, C.; Pietri, S.; Ramos, D.; Rodriguez-Sanchez, J.-L.; Rodríguez-Tajes, C.; Rossi, D.; Schmidt, K.-H.; Simon, H.; Tassan-Got, L.; Törnqvist, H.; Vargas, J.; Voss, B.; Weick, H.; Yan, Y.

    2016-06-01

    The SOFIA (Studies On FIssion with Aladin) experiment aims at measuring fission-fragments isotopic yields with high accuracy using inverse kinematics at relativistic energies. This experimental technique allows to fully identify the fission fragments in nuclear charge and mass number, thus providing very accurate isotopic yields for low energy fission of a large variety of fissioning systems. This report focuses on the latest results obtained with this set-up concerning electromagnetic-induced fission of 236U.

  1. Comparative study of the fragments' mass and energy characteristics in the spontaneous fussion of 238Pu, 240Pu and 242Pu and in the thermal-neutron-induced fission of 239Pu

    NASA Astrophysics Data System (ADS)

    Schillebeeckx, P.; Wagemans, C.; Deruytter, A. J.; Barthélémy, R.

    1992-08-01

    The energy and mass distribution and their correlations have been studied for the spontaneous fission of 238, 240, 242Pu and for the thermal-neutron-induced fission of 239Pu. A comparison of 240Pu(s.f.) and 239Pu(nth,f) shows that the increase in excitation energy mainly results in an increase of the intrinsic excitation energy. A comparison of the results for 238Pu, 240Pu and 242Pu(s.f.) demonstrates the occurence of different fission modes with varying relative probability. These results are discussed in terms of the scission point model as well as in terms of the fission channel model with random neck-rupture.

  2. Dynamical Collective Potential Energy Landscape: Its Impact on the Competition Between Fusion and Quasi-fission in a Heavy Fusing System

    SciTech Connect

    Diaz-Torres, Alexis

    2006-08-14

    A realistic microscopically-based quantum approach to the competition between fusion and quasi-fission in a heavy fusing system is applied to several reactions leading to 256No. Fusion and quasi-fission are described in terms of a diffusion process of nuclear shapes through a dynamical collective potential energy landscape which is initially diabatic and gradually becomes adiabatic. The microscopic ingredients of the theory are obtained with a realistic two-center shell model based on Woods-Saxon potentials. The results indicate that (i) the diabatic effects play a very important role in the onset of fusion hindrance for heavy systems, and (ii) very asymmetric reactions induced by closed shell nuclei seem to be the best suited to synthesize the heaviest compound nuclei.

  3. Simultaneous measurement of (n,γ) and (n,fission) cross sections with the DANCE 4π BaF2 array

    NASA Astrophysics Data System (ADS)

    Bredeweg, T. A.; Fowler, M. M.; Becker, J. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R. C.; Esch, E.-I.; Ethvignot, T.; Granier, T.; Hunt, L. F.; Macri, R. A.; O'Donnell, J. M.; Rundberg, R. S.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Wu, C.-Y.; Yurkon, J. E.

    2006-03-01

    Neutron capture cross section measurements on many of the actinides are complicated by low-energy neutron-induced fission, which competes with neutron capture to varying degrees depending on the nuclide of interest. Measurements of neutron capture on 235U using the Detector for Advanced Neutron Capture Experiments (DANCE) have shown that we can partially resolve capture from fission events based on total photon calorimetry (i.e. total γ-ray energy and γ-ray multiplicity per event). The addition of a fission-tagging detector to the DANCE array will greatly improve our ability to separate these two competing processes so that improved neutron capture and (n,γ)/(n,fission) cross section ratio measurements can be obtained. The addition of a fission-tagging detector to the DANCE array will also provide a means to study several important issues associated with neutron-induced fission, including (n,fission) cross sections as a function of incident neutron energy, and total energy and multiplicity of prompt fission photons. We have focused on two detector designs with complementary capabilities, a parallel-plate avalanche counter and an array of solar cells.

  4. Simultaneous measurement of (n,{gamma}) and (n,fission) cross sections with the DANCE 4{pi} BaF2 array

    SciTech Connect

    Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Chadwick, M. B.; Hunt, L. F.; O'Donnell, J. M.; Rundberg, R. S.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Becker, J. A.; Clement, R. R. C.; Esch, E.-I.; Macri, R. A.; Wu, C.-Y.; Ethvignot, T.; Granier, T.; Yurkon, J. E.

    2006-03-13

    Neutron capture cross section measurements on many of the actinides are complicated by low-energy neutron-induced fission, which competes with neutron capture to varying degrees depending on the nuclide of interest. Measurements of neutron capture on 235U using the Detector for Advanced Neutron Capture Experiments (DANCE) have shown that we can partially resolve capture from fission events based on total photon calorimetry (i.e. total {gamma}-ray energy and {gamma}-ray multiplicity per event). The addition of a fission-tagging detector to the DANCE array will greatly improve our ability to separate these two competing processes so that improved neutron capture and (n,{gamma})/(n,fission) cross section ratio measurements can be obtained. The addition of a fission-tagging detector to the DANCE array will also provide a means to study several important issues associated with neutron-induced fission, including (n,fission) cross sections as a function of incident neutron energy, and total energy and multiplicity of prompt fission photons. We have focused on two detector designs with complementary capabilities, a parallel-plate avalanche counter and an array of solar cells.

  5. Green Energy: Advancing Bio-Hydrogen (Presentation)

    SciTech Connect

    Alber, D.

    2007-07-01

    Developing a model of metabolism linked to H2 production in green algae. Develop tools for parameter discovery and optimization at organism level and advance knowledge of hydrogen-producting photosynthetic organisms.

  6. Bringing Advanced Computational Techniques to Energy Research

    SciTech Connect

    Mitchell, Julie C

    2012-11-17

    Please find attached our final technical report for the BACTER Institute award. BACTER was created as a graduate and postdoctoral training program for the advancement of computational biology applied to questions of relevance to bioenergy research.

  7. [BIOLOGICAL EFFECTIVENESS OF FISSION SPECTRUM NEUTRONS AND PROTONS WITH ENERGIES OF 60-126 MEV DURING ACUTE AND PROLONGED IRRADIATION].

    PubMed

    Shafirkin, A V

    2015-01-01

    Neutrons of the fission spectrum are characterized by relatively high values of linear energy transfer (LET). Data about their effects on biological objects are used to evaluate the risk of delayed effects of accelerated ions within the same LET range that serve as an experimental model of the nuclei component of galactic cosmic rays (GCR). Additionally, risks of delayed consequences to cosmonaut's health and average lifetime from certain GCR fluxes and secondary neutrons can be also prognosticated. The article deals with comparative analysis of the literature on reduction of average lifespan (ALS) of animals exposed to neutron reactor spectrum, 60-126 MeV protons, and X- and γ-rays in a broad range of radiation intensity and duration. It was shown that a minimal lifespan reduction by 5% occurs due to a brief exposure to neutrons with the absorbed dose of 5 cGy, whereas same lifespan reduction due to hard X- and γ-radiation occurs after absorption of a minimal dose of 100 cGy. Therefore, according to the estimated minimal ALS reduction in mice, neutron effectiveness is 20-fold higher. Biological effectiveness of protons as regards ALS reduction is virtually equal to that of standard types of radiation. Exposure to X- and γ-radiation with decreasing daily doses, and increasing number of fractions and duration gives rise to an apparent trend toward a less dramatic ALS reduction in mice; on the contrary, exposure to neutrons of varying duration had no effect on threshold doses for the specified ALS reductions. Factors of relative biological effectiveness of neutrons reached 40. PMID:26934784

  8. [BIOLOGICAL EFFECTIVENESS OF FISSION SPECTRUM NEUTRONS AND PROTONS WITH ENERGIES OF 60-126 MEV DURING ACUTE AND PROLONGED IRRADIATION].

    PubMed

    Shafirkin, A V

    2015-01-01

    Neutrons of the fission spectrum are characterized by relatively high values of linear energy transfer (LET). Data about their effects on biological objects are used to evaluate the risk of delayed effects of accelerated ions within the same LET range that serve as an experimental model of the nuclei component of galactic cosmic rays (GCR). Additionally, risks of delayed consequences to cosmonaut's health and average lifetime from certain GCR fluxes and secondary neutrons can be also prognosticated. The article deals with comparative analysis of the literature on reduction of average lifespan (ALS) of animals exposed to neutron reactor spectrum, 60-126 MeV protons, and X- and γ-rays in a broad range of radiation intensity and duration. It was shown that a minimal lifespan reduction by 5% occurs due to a brief exposure to neutrons with the absorbed dose of 5 cGy, whereas same lifespan reduction due to hard X- and γ-radiation occurs after absorption of a minimal dose of 100 cGy. Therefore, according to the estimated minimal ALS reduction in mice, neutron effectiveness is 20-fold higher. Biological effectiveness of protons as regards ALS reduction is virtually equal to that of standard types of radiation. Exposure to X- and γ-radiation with decreasing daily doses, and increasing number of fractions and duration gives rise to an apparent trend toward a less dramatic ALS reduction in mice; on the contrary, exposure to neutrons of varying duration had no effect on threshold doses for the specified ALS reductions. Factors of relative biological effectiveness of neutrons reached 40.

  9. Structure of matter, radioactivity, and nuclear fission. Volume 3

    SciTech Connect

    Not Available

    1986-01-01

    Subject matter includes structure of matter (what is matter, forces holding atoms together, visualizing the atom, the chemical elements, atomic symbols, isotopes, radiation from the atom), radioactivity (what holds the nucleus together, can one element change into another element, radiation from the nucleus, half-life, chart of the nuclides), and nuclear fission (nuclear energy release, the fission process, where does fission energy go, radiation and radioactivity resulting from fission).

  10. Search for instantaneous radiation near the instant of break momentum of various fissioning nuclear systems at low excitation energies

    SciTech Connect

    Vorobyev, A. S. Val'ski, G. V.; Gagarskii, A. M.; Guseva, I. S.; Petrov, G. A.; Petrova, V. I.; Serebrin, A. Yu.; Sokolov, V. E.; Shcherbakov, O. A.

    2011-12-15

    The main results of studying the properties of 'instantaneous' neutrons and {gamma} photons during the fission of {sup 233,235}U(n{sub th}, f) and {sup 239}Pu(n{sub th}, f) nuclei and spontaneous fission of {sup 252}Cf, which were performed on the WWR-M reactor at the St. Petersburg Nuclear Physics Institute, Russian Academy of Sciences, are presented. Along with obtaining the main characteristics of the instantaneous radiation from fission fragments, these studies were also aimed at gaining deeper insight into such exotic processes as the emission of break neutrons and {gamma} photons from a fissioning nucleus near the break point. These investigations were performed on different experimental setups using different analytical methods. This approach allowed us not only to find but also to reduce to minimum possible systematic effects. The yields of break neutrons were found to be about (5-7) Multiplication-Sign 10{sup -2} of the total number of neutrons per {sup 233,235}U(n, f) fission event and approximately twice as much for {sup 239}Pu(n, f) and {sup 252}Cf. The coefficient of T-odd asymmetry for {gamma} photons is in agreement with the estimate obtained on the assumption that the observed effect is mainly related to the {gamma} photons emitted by excited fragments with highly oriented angular momenta. This fact gave grounds to conclude that the desired break {gamma} photons cannot be reliably selected (within the obtained experimental accuracy) against the much larger background of {gamma} photons from fission fragments.

  11. Total prompt γ-ray emission in fission

    NASA Astrophysics Data System (ADS)

    Wu, C. Y.; Chyzh, A.; Kwan, E.; Henserson, R. A.; Bredeweg, T. A.; Haight, R. C.; Hayes-Sterbenz, A. C.; Lee, H. Y.; O'Donnell, J. M.; Ullmann, J. L.

    2016-06-01

    The total prompt γ-ray energy distributions for the neutron-induced fission of 235U, 239,241Pu at incident neutron energy of 0.025 eV ‒ 100 keV, and the spontaneous fission of 252Cf were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) array in coincidence with the detection of fission fragments by a parallel-plate avalanche counter. DANCE is a highly segmented, highly efficient 4π γ-ray calorimeter. Corrections were made to the measured distribution by unfolding the two-dimension spectrum of total γ-ray energy vs multiplicity using a simulated DANCE response matrix. The mean values of the total prompt γ-ray energy, determined from the unfolded distributions, are ~ 20% higher than those derived from measurements using single γ-ray detector for all the fissile nuclei studied. This raises serious concern on the validity of the mean total prompt γ-ray energy obtained from the product of mean values for both prompt γ-ray energy and multiplicity.

  12. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  13. Thermal System Interactions in Optimizing Advanced Thermoelectric Energy Recovery Systems

    SciTech Connect

    Hendricks, Terry J.

    2007-09-01

    Energy recovery is gaining importance in various transportation and industrial process applications because of rising energy costs and geopolitical uncertainties impacting basic energy supplies. Various advanced thermoelectric (TE) materials have properties that are inherently advantageous for particular TE energy recovery applications. Skutterudites, 0- and 1-dimensional quantum-well materials, and thin-film superlattice materials are providing enhanced opportunities for advanced TE energy recovery in transportation and industrial processes. This work demonstrates: 1) the potential for advanced thermoelectric systems in vehicle energy recovery, and 2) the inherently complex interaction between thermal system performance and thermoelectric device optimization in energy recovery. Potential power generation at specific exhaust temperature levels and for various heat exchanger performance levels is presented showing the current design sensitivities using different TE material sets. Mathematical relationships inherently linking optimum TE design variables and the thermal systems design (i.e., heat exchangers and required mass flow rates) are also investigated and characterized.

  14. Thermal System Interactions in Optimizing Advanced Thermoelectric Energy Recovery Systems

    SciTech Connect

    Hendricks, Terry J.

    2007-12-01

    Energy recovery is gaining importance in various transportation and industrial process applications because of rising energy costs and geopolitical uncertainties impacting basic energy supplies. Various advanced thermoelectric (TE) materials have properties that are inherently advantageous for particular TE energy recovery applications. Skutterudites, 0- and 1-dimensional quantum-well materials, and thin-film superlattice materials are providing enhanced opportunities for advanced TE energy recovery in transportation and industrial processes. This work demonstrates: 1) the potential for advanced thermoelectric systems in vehicle energy recovery, and 2) the inherently complex interaction between thermal system performance and thermoelectric device optimization in energy recovery. Potential power generation at specific exhaust temperature levels and for various heat exchanger performance levels are presented showing the current design sensitivities using different TE material sets. Mathematical relationships inherently linking optimum TE design variables and the thermal systems design (i.e., heat exchangers and required mass flow rates) are also investigated and characterized.

  15. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    NASA Astrophysics Data System (ADS)

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Phongikaroon, Supathorn; Sattarov, Akhdiyor; Simpson, Michael; Sooby, Elizabeth; Tsvetkov, Pavel

    2013-04-01

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  16. Accelerator-driven subcritical fission in molten salt core: Closing the nuclear fuel cycle for green nuclear energy

    SciTech Connect

    McIntyre, Peter; Assadi, Saeed; Badgley, Karie; Baker, William; Comeaux, Justin; Gerity, James; Kellams, Joshua; McInturff, Al; Pogue, Nathaniel; Sattarov, Akhdiyor; Sooby, Elizabeth; Tsvetkov, Pavel; Phongikaroon, Supathorn; Simpson, Michael

    2013-04-19

    A technology for accelerator-driven subcritical fission in a molten salt core (ADSMS) is being developed as a basis for the destruction of the transuranics in used nuclear fuel. The molten salt fuel is a eutectic mixture of NaCl and the chlorides of the transuranics and fission products. The core is driven by proton beams from a strong-focusing cyclotron stack. This approach uniquely provides an intrinsically safe means to drive a core fueled only with transuranics, thereby eliminating competing breeding terms.

  17. Development of ODS FeCrAl for compatibility in fusion and fission energy applications

    DOE PAGES

    Pint, Bruce A.; Dryepondt, Sebastien N.; Unocic, Kinga A.; Hoelzer, David T.

    2014-11-15

    In this paper, oxide dispersion strengthened (ODS) FeCrAl alloys with 12–15% Cr are being evaluated for improved compatibility with Pb-Li for a fusion energy application and with high temperature steam for a more accident-tolerant light water reactor fuel cladding application. A 12% Cr content alloy showed low mass losses in static Pb-Li at 700°C, where a LiAlO2 surface oxide formed and inhibited dissolution into the liquid metal. All the evaluated compositions formed a protective scale in steam at 1200°C, which is not possible with ODS FeCr alloys. However, most of the compositions were not protective at 1400°C, which is amore » general and somewhat surprising problem with ODS FeCrAl alloys that is still being studied. More work is needed to optimize the alloy composition, microstructure and oxide dispersion, but initial promising tensile and creep results have been obtained with mixed oxide additions, i.e. Y2O3 with ZrO2, HfO2 or TiO2.« less

  18. Development of ODS FeCrAl for Compatibility in Fusion and Fission Energy Applications

    NASA Astrophysics Data System (ADS)

    Pint, B. A.; Dryepondt, S.; Unocic, K. A.; Hoelzer, D. T.

    2014-12-01

    Oxide dispersion strengthened (ODS) FeCrAl alloys with 12-15% Cr are being evaluated for improved compatibility with Pb-Li for a fusion energy application and with high temperature steam for a more accident-tolerant light water reactor fuel cladding application. A 12% Cr content alloy showed low mass losses in static Pb-Li at 700°C, where a LiAlO2 surface oxide formed and inhibited dissolution into the liquid metal. All the evaluated compositions formed a protective scale in steam at 1200°C, which is not possible with ODS FeCr alloys. However, most of the compositions were not protective at 1400°C, which is a general and somewhat surprising problem with ODS FeCrAl alloys that is still being studied. More work is needed to optimize the alloy composition, microstructure and oxide dispersion, but initial promising tensile and creep results have been obtained with mixed oxide additions, i.e. Y2O3 with ZrO2, HfO2 or TiO2.

  19. Development of ODS FeCrAl for compatibility in fusion and fission energy applications

    SciTech Connect

    Pint, Bruce A.; Dryepondt, Sebastien N.; Unocic, Kinga A.; Hoelzer, David T.

    2014-11-15

    In this paper, oxide dispersion strengthened (ODS) FeCrAl alloys with 12–15% Cr are being evaluated for improved compatibility with Pb-Li for a fusion energy application and with high temperature steam for a more accident-tolerant light water reactor fuel cladding application. A 12% Cr content alloy showed low mass losses in static Pb-Li at 700°C, where a LiAlO2 surface oxide formed and inhibited dissolution into the liquid metal. All the evaluated compositions formed a protective scale in steam at 1200°C, which is not possible with ODS FeCr alloys. However, most of the compositions were not protective at 1400°C, which is a general and somewhat surprising problem with ODS FeCrAl alloys that is still being studied. More work is needed to optimize the alloy composition, microstructure and oxide dispersion, but initial promising tensile and creep results have been obtained with mixed oxide additions, i.e. Y2O3 with ZrO2, HfO2 or TiO2.

  20. Advanced research in solar-energy storage

    SciTech Connect

    Luft, W.

    1983-01-01

    The Solar Energy Storage Program at the Solar Energy Research Institute is reviewed. The program provides research, systems analyses, and economic assessments of thermal and thermochemical energy storage and transport. Current activities include experimental research into very high temperature (above 800/sup 0/C) thermal energy storage and assessment of novel thermochemical energy storage and transport systems. The applications for such high-temperature storage are thermochemical processes, solar thermal-electric power generation, cogeneration of heat and electricity, industrial process heat, and thermally regenerative electrochemical systems. The research results for five high-temperature thermal energy storage technologies and two thermochemical systems are described.

  1. Advanced Energy Projects: FY 1993, Research summaries

    SciTech Connect

    Not Available

    1993-09-01

    AEP has been supporting research on novel materials for energy technology, renewable and biodegradable materials, new uses for scientific discoveries, alternate pathways to energy efficiency, alternative energy sources, innovative approaches to waste treatment and reduction, etc. The summaries are grouped according to projects active in FY 1993, Phase I SBIR projects, and Phase II SBIR projects. Investigator and institutional indexes are included.

  2. Spontaneous fission properties and lifetime systematics

    SciTech Connect

    Hoffman, D.C.

    1989-03-01

    Half-lives for spontaneous fission of nuclides with even and odd numbers of particles are compared with recent theoretical calculations. A summary of odd particle hindrance factors is given. The most recent measurements of kinetic-energy and mass distributions and neutron emission for spontaneous fission of the heaviest nuclides are summarized and discussed. 51 refs., 9 figs.

  3. Prompt fission neutron spectra of actinides

    DOE PAGES

    Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; Kornilov, N. V.; Lestone, J. P.; Litaize, O.; Morillon, B.; Neudecker, D.; Oberstedt, S.; Ohsawa, T.; et al

    2016-01-06

    Here, the energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  4. SOURCE OF PRODUCTS OF NUCLEAR FISSION

    DOEpatents

    Harteck, P.; Dondes, S.

    1960-03-15

    A source of fission product recoil energy suitable for use in radiation chemistry is reported. The source consists of thermal neutron irradiated glass wool having a diameter of 1 to 5 microns and containing an isotope fissionable by thermal neutrons, such as U/sup 235/.

  5. Advanced energy systems and technologies research programme

    NASA Astrophysics Data System (ADS)

    Lund, P.; Tuominen, E.

    NEMO 2 is a national energy research program for the evaluation, development and promotion of new and renewable forms of energy. NEMO 2 is one of the energy research programs of the Finnish Ministry of Trade and Industry for the years 1993-1998. In NEMO 2 -program, new energy technology is developed as a whole in close collaboration between industry, universities and research institutes, as well as with customers and consumers. The overall budget of NEMO 2 is close to 125 MFIM (1 dollar = 5.7 FIM, Nov. 1993). The main emphasis of the program is on wind and solar energy.

  6. Fission-fragment angular distributions and total kinetic energies for /sup 235/U(n,f) from. 18 to 8. 83 MeV

    SciTech Connect

    Meadows, J.W.; Budtz-Joergensen, C.

    1982-01-01

    A gridded ion chamber was used to measure the fission fragment angular distribution and total kinetic energy for the /sup 235/U(n,f) reaction from 0.18 to 8.81 MeV neutron energy. The anisotropies are in generally good agreement with earlier measurements. The average total kinetic energy is approx. 0.2 MeV greater than the thermal value at neutron energies < 2 MeV and shows a sudden decrease of approx. 0.8 MeV between 4 and 5 MeV neutron energy, well below the (n, n'f) threshold. Possible causes of this decrease are a change in the mass distribution or decreased shell effects in the heavy fragment.

  7. Advanced energy projects; FY 1995 research summaries

    SciTech Connect

    1995-09-01

    The AEP Division supports projects to explore novel energy-related concepts which are typically at an early stage of scientific development, and high-risk, exploratory concepts. Topical areas presently receiving support are: novel materials for energy technology, renewable and biodegradable materials, exploring uses of new scientific discoveries, alternate pathways to energy efficiency, alternative energy sources, and innovative approaches to waste treatment and reduction. There were 46 research projects during FY 1995; ten were initiated during that fiscal year. The summaries are separated into grant and laboratory programs, and small business innovation research programs.

  8. Curved Waveguide Based Nuclear Fission for Small, Lightweight Reactors

    NASA Technical Reports Server (NTRS)

    Coker, Robert; Putnam, Gabriel

    2012-01-01

    advance could be applied to direct propulsion through guided fission products or as a secondary energy source for high impulse electric propulsion. It would help meet national needs for highly efficient energy sources with limited dependence on fossil fuels or conflict materials, and it would improve the use of low grade fissile materials which would help reduce national stockpiles and waste.

  9. Regional characteristics relevant to advanced technology cogeneration development. [industrial energy

    NASA Technical Reports Server (NTRS)

    Manvi, R.

    1981-01-01

    To assist DOE in establishing research and development funding priorities in the area of advanced energy conversion technoloy, researchers at the Jet Propulsion Laboratory studied those specific factors within various regions of the country that may influence cogeneration with advanced energy conversion systems. Regional characteristics of advanced technology cogeneration possibilities are discussed, with primary emphasis given to coal derived fuels. Factors considered for the study were regional industry concentration, purchased fuel and electricity prices, environmental constraints, and other data of interest to industrial cogeneration.

  10. Spontaneous fission properties of the heavy elements: Bimodal fission

    SciTech Connect

    Hulet, E.K.

    1988-11-11

    We have measured the mass and kinetic-energy distributions from the spontaneous fission of SVYFm, SVYNo, SVZMd, SWMd, SW(104), and SWSNo. All are observed to fission with a symmetrical division of mass, whereas the total-kinetic-energy (TKE) distributions strongly deviated from the Gaussian shape characteristically found in the fission of all other actinides. When the TKE distributions are resolved into two Gaussian's, the constituent peaks lie near 200 and near 233 MeV. We conclude two modes or bimodal fission is occurring in five of the six nuclides studied. Both modes are possible in the same nuclide, but one generally predominates. We also conclude the low-energy but mass-symmetrical mode is likely to extend to far heavier nuclei; while the high-energy mode will be restricted to a smaller region, a region of nuclei defined by the proximity of the fragments to the strong neutron and proton shells in TSSn. 21 refs., 7 figs., 1 tab.

  11. Monte carlo sampling of fission multiplicity.

    SciTech Connect

    Hendricks, J. S.

    2004-01-01

    Two new methods have been developed for fission multiplicity modeling in Monte Carlo calculations. The traditional method of sampling neutron multiplicity from fission is to sample the number of neutrons above or below the average. For example, if there are 2.7 neutrons per fission, three would be chosen 70% of the time and two would be chosen 30% of the time. For many applications, particularly {sup 3}He coincidence counting, a better estimate of the true number of neutrons per fission is required. Generally, this number is estimated by sampling a Gaussian distribution about the average. However, because the tail of the Gaussian distribution is negative and negative neutrons cannot be produced, a slight positive bias can be found in the average value. For criticality calculations, the result of rejecting the negative neutrons is an increase in k{sub eff} of 0.1% in some cases. For spontaneous fission, where the average number of neutrons emitted from fission is low, the error also can be unacceptably large. If the Gaussian width approaches the average number of fissions, 10% too many fission neutrons are produced by not treating the negative Gaussian tail adequately. The first method to treat the Gaussian tail is to determine a correction offset, which then is subtracted from all sampled values of the number of neutrons produced. This offset depends on the average value for any given fission at any energy and must be computed efficiently at each fission from the non-integrable error function. The second method is to determine a corrected zero point so that all neutrons sampled between zero and the corrected zero point are killed to compensate for the negative Gaussian tail bias. Again, the zero point must be computed efficiently at each fission. Both methods give excellent results with a negligible computing time penalty. It is now possible to include the full effects of fission multiplicity without the negative Gaussian tail bias.

  12. Advanced concepts for controlling energy surety microgrids.

    SciTech Connect

    Menicucci, David F.; Ortiz-Moyet, Juan

    2011-05-01

    Today, researchers, engineers, and policy makers are seeking ways to meet the world's growing demand for energy while addressing critical issues such as energy security, reliability, and sustainability. Many believe that distributed generators operating within a microgrid have the potential to address most of these issues. Sandia National Laboratories has developed a concept called energy surety in which five of these 'surety elements' are simultaneously considered: energy security, reliability, sustainability, safety, and cost-effectiveness. The surety methodology leads to a new microgrid design that we call an energy surety microgrid (ESM). This paper discusses the unique control requirement needed to produce a microgrid system that has high levels of surety, describes the control system from the most fundamental level through a real-world example, and discusses our ideas and concepts for a complete system.

  13. Fission measurements with PPAC detectors using a coincidence technique

    SciTech Connect

    Paradela, C.; Duran, I.; Tarrio, D.; Audouin, L.; Tassan-Got, L.; Stephan, C.

    2011-07-01

    A fission detection setup based on Parallel Plate Avalanche Counters (PPAC) has been constructed and used at the CERN n-TOF facility. The setup takes advantage of the coincidence detection of both fission fragments to discriminate the background reactions produced by high energy neutrons and it allows obtaining neutron-induced fission cross section up to 1 GeV. (authors)

  14. SPIDER Progress Towards High Resolution Correlated Fission Product Data

    NASA Astrophysics Data System (ADS)

    Shields, Dan; Meierbachtol, Krista; Tovesson, Fredrik; Arnold, Charles; Blackeley, Rick; Bredeweg, Todd; Devlin, Matt; Hecht, Adam; Jandel, Marian; Jorgenson, Justin; Nelson, Ron; White, Morgan; Spider Team

    2014-09-01

    The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) is under development with the goal of obtaining high-resolution, high-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (ν), and total kinetic energy (TKE). A detailed description of the prototype SPIDER detector components will be presented. Characterization measurements with alpha and spontaneous fission sources will also be discussed. LA-UR-14-24875. The SPIDER detector (SPectrometer for Ion DEtermination in fission Research) is under development with the goal of obtaining high-resolution, high-efficiency, correlated fission product data needed for many applications including the modeling of next generation nuclear reactors, stockpile stewardship, and the fundamental understanding of the fission process. SPIDER simultaneously measures velocity and energy of both fission products to calculate fission product yields (FPYs), neutron multiplicity (ν), and total kinetic energy (TKE). A detailed description of the prototype SPIDER detector components will be presented. Characterization measurements with alpha and spontaneous fission sources will also be discussed. LA-UR-14-24875. This work is in part supported by LANL Laboratory Directed Research and Development Projects 20110037DR and 20120077DR.

  15. Modeling Innovations Advance Wind Energy Industry

    NASA Technical Reports Server (NTRS)

    2009-01-01

    In 1981, Glenn Research Center scientist Dr. Larry Viterna developed a model that predicted certain elements of wind turbine performance with far greater accuracy than previous methods. The model was met with derision from others in the wind energy industry, but years later, Viterna discovered it had become the most widely used method of its kind, enabling significant wind energy technologies-like the fixed pitch turbines produced by manufacturers like Aerostar Inc. of Westport, Massachusetts-that are providing sustainable, climate friendly energy sources today.

  16. Fission barriers in a macroscopic-microscopic model

    SciTech Connect

    Dobrowolski, A.; Pomorski, K.; Bartel, J.

    2007-02-15

    In the framework of the macroscopic-microscopic model, this study investigates fission barriers in the region of actinide nuclei. A very effective four-dimensional shape parametrization for fissioning nuclei is proposed. Taking, in particular, the left-right mass asymmetric and nonaxial shapes into account is demonstrated to have a substantial effect on fission barrier heights. The influence of proton versus neutron deformation differences on the potential energy landscape of fissioning nuclei is also discussed.

  17. New results on the ternary fission of 243Cm

    NASA Astrophysics Data System (ADS)

    Heyse, J.; Wagemans, C.; Vermote, S.; Serot, O.; Geltenbort, P.; Soldner, T.; Van Gils, J.

    2005-11-01

    Ternary fission is an important source of He and tritium gas in nuclear reactors and used fuel elements. Therefore a systematic study of the ternary fission yields for 4He and tritons (t) is being performed. In recent years the influence of the excitation energy of the fissioning nucleus on the triton emission probability (t/B) has been investigated for different Cm and Cf isotopes. In this paper we report on new results on the neutron induced fission of 243Cm.

  18. Advanced Membrane Separation Technologies for Energy Recovery

    SciTech Connect

    2009-05-01

    This factsheet describes a research project whose goal is to develop novel materials for use in membrane separation technologies for the recovery of waste energy and water from industrial process streams.

  19. Geometry of membrane fission.

    PubMed

    Frolov, Vadim A; Escalada, Artur; Akimov, Sergey A; Shnyrova, Anna V

    2015-01-01

    Cellular membranes define the functional geometry of intracellular space. Formation of new membrane compartments and maintenance of complex organelles require division and disconnection of cellular membranes, a process termed membrane fission. Peripheral membrane proteins generally control membrane remodeling during fission. Local membrane stresses, reflecting molecular geometry of membrane-interacting parts of these proteins, sum up to produce the key membrane geometries of fission: the saddle-shaped neck and hour-glass hemifission intermediate. Here, we review the fundamental principles behind the translation of molecular geometry into membrane shape and topology during fission. We emphasize the central role the membrane insertion of specialized protein domains plays in orchestrating fission in vitro and in cells. We further compare individual to synergistic action of the membrane insertion during fission mediated by individual protein species, proteins complexes or membrane domains. Finally, we describe how local geometry of fission intermediates defines the functional design of the protein complexes catalyzing fission of cellular membranes. PMID:25062896

  20. Thorium-uranium fission radiography

    NASA Technical Reports Server (NTRS)

    Haines, E. L.; Weiss, J. R.; Burnett, D. S.; Woolum, D. S.

    1976-01-01

    Results are described for studies designed to develop routine methods for in-situ measurement of the abundance of Th and U on a microscale in heterogeneous samples, especially rocks, using the secondary high-energy neutron flux developed when the 650 MeV proton beam of an accelerator is stopped in a 42 x 42 cm diam Cu cylinder. Irradiations were performed at three different locations in a rabbit tube in the beam stop area, and thick metal foils of Bi, Th, and natural U as well as polished silicate glasses of known U and Th contents were used as targets and were placed in contact with mica which served as a fission track detector. In many cases both bare and Cd-covered detectors were exposed. The exposed mica samples were etched in 48% HF and the fission tracks counted by conventional transmitted light microscopy. Relative fission cross sections are examined, along with absolute Th track production rates, interaction tracks, and a comparison of measured and calculated fission rates. The practicality of fast neutron radiography revealed by experiments to data is discussed primarily for Th/U measurements, and mixtures of other fissionable nuclei are briefly considered.

  1. MEASUREMENT OF THE AVERAGE ENERGY AND MULTIPLICITY OF PROMPT-FISSION-NEUTRONS FROM 238U(n,f) AND 237 Np(n,f) FROM 1 TO 200 MeV.

    SciTech Connect

    TAIEB,J.; GRANIER, T.; ETHVIGNOT, T.; DEVLIN, M.; HAIGHT, R.C.; NELSON, R.O.; ODONNELL, J.M.; ROCHMAN, D.

    2007-06-28

    Taking advantage of the neutron source of the LANCSE, it has been possible to obtain a measure of the velocity distribution and the number of prompt-neutrons emitted in the neutron-induced fission of {sup 238}U and {sup 237}Np over a broad incident neutron energy range. The mean kinetic energy was extracted and is shown as the function of the incident-neutron energy. We confirm here the observation, for both reactions, of a dip around the second chance fission which is explained by the lower kinetic energy of the pre-fission neutrons. Such a observation is reproduced by Los Alamos model as implemented at Bruyeres le Chatel and by the Maslov model. As far as the neutron multiplicity is concerned, a similar dip is observed. However, such a behavior is not present in data measured by other groups.

  2. Organelle fission in eukaryotes.

    PubMed

    Osteryoung, K W

    2001-12-01

    The cellular machineries that power chloroplast and mitochondrial division in eukaryotes carry out the topologically challenging job of constricting and severing these double-membraned organelles. Consistent with their endosymbiotic origins, mitochondria in protists and chloroplasts in photosynthetic eukaryotes have evolved organelle-targeted forms of FtsZ, the prokaryotic ancestor of tubulin, as key components of their fission complexes. In fungi, animals and plants, mitochondria no longer utilize FtsZ for division, but several mitochondrial division proteins that localize to the outer membrane and intermembrane space, including two related to the filament-forming dynamins, have been identified in yeast and animals. Although the reactions that mediate organelle division are not yet understood, recent progress in uncovering the constituents of the organelle division machineries promises rapid advancement in our understanding of the biochemical mechanisms underlying the distinct but related processes of chloroplast and mitochondrial division in eukaryotes.

  3. Fission-fusion neutron source

    NASA Astrophysics Data System (ADS)

    Yu, Jinnan; Yu, Gang

    2009-04-01

    In order to meet the requirements of fusion power reactors and nuclear waste treatment, a concept of fission-fusion neutron source is proposed, which consists of a LiD assembly located in the heavy water region of the China Advanced Research Reactor. This assembly of LiD fuel rods will be irradiated with slow neutrons and will produce fusion neutrons in the central hole via the reaction 6Li(n, α). More precisely, tritium ions with a high energy of 2.739 MeV will be produced in LiD by the impinging slow neutrons. The tritium ions will in turn bombard the deuterium ions present in the LiD assembly, which will induce fusion reaction and then the production of 14 MeV neutrons. The fusion reaction rate will increase with the accumulation of tritium in LiD by the reaction between tritium and deuteron recoils produced by the 14 MeV neutrons. When the concentration of tritium reaches 0.5 · 10 22 and the fraction of fusion reactions between tritium and deuteron recoils approaches 1, the 14 MeV neutron flux is doubled and redoubled, an so forth, approaching saturation in which the tritium produced at a time t is exhausted by the fusion reactions to keep constant the tritium concentration in LiD.

  4. NEMO: Advanced energy systems and technologies

    NASA Astrophysics Data System (ADS)

    Beckman, W. A.; Petersen, E. L.; Sellberg, B.

    The NEMO program, one of ten Finnish energy research programs, has supported research and development in wind energy storage and solar energy systems since 1988. The focus is on problems of particular interest to Finland with emphasis on technologies that may be important within the next 10 years. The projects covered the range from product development in close collaboration with industrial partners to basic research. The committee was generally impressed with the level of competence of the research teams. It is clear that in some areas the Finnish research is on a par with the best in the world. In some areas the research may be described as being in a necessary 'catch-up' phase. Although the program is less than three years old, the results to date are encouraging and the committee recommends continuing NEMO or a similar program beyond 1992. Specific observations are included in the final section of this report.

  5. Research opportunities to advance solar energy utilization.

    PubMed

    Lewis, Nathan S

    2016-01-22

    Major developments, as well as remaining challenges and the associated research opportunities, are evaluated for three technologically distinct approaches to solar energy utilization: solar electricity, solar thermal, and solar fuels technologies. Much progress has been made, but research opportunities are still present for all approaches. Both evolutionary and revolutionary technology development, involving foundational research, applied research, learning by doing, demonstration projects, and deployment at scale will be needed to continue this technology-innovation ecosystem. Most of the approaches still offer the potential to provide much higher efficiencies, much lower costs, improved scalability, and new functionality, relative to the embodiments of solar energy-conversion systems that have been developed to date.

  6. Application of the dinuclear system model to fission process

    NASA Astrophysics Data System (ADS)

    Andreev, A. V.; Shneidman, T. M.; Ventura, A.

    2016-01-01

    A theoretical evaluation of the collective excitation spectra of nucleus at large deformations is possible within the framework of the dinuclear system model, which treats the wave function of the fissioning nucleus as a superposition of a mononucleus configuration and two-cluster configurations in a dynamical way, permitting exchange of nucleons between clusters. In this work the method of calculation of the potential energy and the collective spectrum of fissioning nucleus at scission point is presented. Combining the DNS model calculations and the statistical model of fission we calculate the mass, total kinetic energy, and angular distribution of fission fragments for the neutron-induced fission of 239Pu.

  7. Fission dynamics within time-dependent Hartree-Fock. II. Boost-induced fission

    NASA Astrophysics Data System (ADS)

    Goddard, Philip; Stevenson, Paul; Rios, Arnau

    2016-01-01

    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: We explore the ability of dynamic mean-field methods to describe induced fission processes, using quadrupole boosts in the nuclide 240Pu as an example. Methods: Following upon the work presented in Goddard et al. [Phys. Rev. C 92, 054610 (2015)], 10.1103/PhysRevC.92.054610, quadrupole-constrained Hartree-Fock calculations are used to create a potential energy surface. An isomeric state and a state beyond the second barrier peak are excited by means of instantaneous as well as temporally extended gauge boosts with quadrupole shapes. The subsequent deexcitation is studied in a time-dependent Hartree-Fock simulation, with emphasis on fissioned final states. The corresponding fission fragment mass numbers are studied. Results: In general, the energy deposited by the quadrupole boost is quickly absorbed by the nucleus. In instantaneous boosts, this leads to fast shape rearrangements and violent dynamics that can ultimately lead to fission. This is a qualitatively different process than the deformation-induced fission. Boosts induced within a finite time window excite the system in a relatively gentler way and do induce fission but with a smaller energy deposition. Conclusions: The fission products obtained using boost-induced fission in time-dependent Hartree-Fock are more asymmetric than the fragments obtained in deformation-induced fission or the corresponding adiabatic approaches.

  8. SOFIA, a Next-Generation Facility for Fission Yields Measurements and Fission Study. First Results and Perspectives

    NASA Astrophysics Data System (ADS)

    Audouin, L.; Pellereau, E.; Taieb, J.; Boutoux, G.; Béliera, G.; Chatillon, A.; Ebran, A.; Gorbinet, T.; Laurent, B.; Martin, J.-F.; Tassan-Got, L.; Jurado, B.; Alvarez-Pol, H.; Ayyad, Y.; Benlliure, J.; Caamano, M.; Cortina-Gil, D.; Fernandez-Dominguez, B.; Paradela, C.; Rodriguez-Sanchez, J.-L.; Vargas, J.; Casarejos, E.; Heinz, A.; Kelic-Heil, A.; Kurz, N.; Nociforo, C.; Pietri, S.; Prochazka, A.; Rossi, D.; Schmidt, K.-H.; Simon, H.; Voss, B.; Weick, H.; Winfield, J. S.

    2015-10-01

    Fission fragments play an important role in nuclear reactors evolution and safety. However, fragments yields are poorly known : data are essentially limited to mass yields from thermal neutron-induced fissions on a very few nuclei. SOFIA (Study On FIssion with Aladin) is an innovative experimental program on nuclear fission carried out at the GSI facility, which aims at providing isotopic yields on a broad range of fissioning systems. Relativistic secondary beams of actinides and pre-actinides are selected by the Fragment Separator (FRS) and their fission is triggered by electromagnetic interaction. The resulting excitation energy is comparable to the result of an interaction with a low-energy neutron, thus leading to useful data for reactor simulations. For the first time ever, both fission fragments are completely identified in charge and mass in a new recoil spectrometer, allowing for precise yields measurements. The yield of prompt neutrons can then be deduced, and the fission mechanism can be ascribed, providing new constraints for fission models. During the first experiment, all the technical challenges were matched : we have thus set new experimental standards in the measurements of relativistic heavy ions (time of flight, position, energy loss).This communication presents a first series of results obtained on the fission of 238U; many other fissioning systems have also been measured and are being analyzed presently. A second SOFIA experiment is planned in September 2014, and will be focused on the measurement of the fission of 236U, the analog of 235U+n.

  9. Effects of Neutron Emission on Fragment Mass and Kinetic Energy Distribution from Thermal Neutron-Induced Fission of {sup 235}U

    SciTech Connect

    Montoya, M.; Rojas, J.; Saetone, E.

    2007-10-26

    The mass and kinetic energy distribution of nuclear fragments from thermal neutron-induced fission of {sup 235}U(n{sub th},f) have been studied using a Monte-Carlo simulation. Besides reproducing the pronounced broadening in the standard deviation of the kinetic energy at the final fragment mass number around m = 109, our simulation also produces a second broadening around m = 125. These results are in good agreement with the experimental data obtained by Belhafaf et al. and other results on yield of mass. We conclude that the obtained results are a consequence of the characteristics of the neutron emission, the sharp variation in the primary fragment kinetic energy and mass yield curves. We show that because neutron emission is hazardous to make any conclusion on primary quantities distribution of fragments from experimental results on final quantities distributions.

  10. Apparatus for advancing a wellbore using high power laser energy

    DOEpatents

    Zediker, Mark S.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.

    2014-09-02

    Delivering high power laser energy to form a borehole deep into the earth using laser energy. Down hole laser tools, laser systems and laser delivery techniques for advancement, workover and completion activities. A laser bottom hole assembly (LBHA) for the delivery of high power laser energy to the surfaces of a borehole, which assembly may have laser optics, a fluid path for debris removal and a mechanical means to remove earth.

  11. Energy Department Helps Advance Island Clean Energy Goals (Fact Sheet)

    SciTech Connect

    Not Available

    2012-10-01

    This U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE) fact sheet highlights a June 2012 solar power purchase agreement between the Virgin Islands Water and Power Authority and three corporations. The fact sheet describes how financial support from DOE and technical assistance from DOE's National Renewable Energy Laboratory enabled the U.S. Virgin Islands to realistically assess its clean energy resources and identify the most viable and cost-effective solutions to its energy challenges--resulting in a $65 million investment in solar energy in the territory.

  12. Maruhn-Greiner Maximum of Uranium Fission for Confirmation of Low Energy Nuclear Reactions LENR via a Compound Nucleus with Double Magic Numbers

    NASA Astrophysics Data System (ADS)

    Hora, H.; Miley, G. H.

    2007-12-01

    One of the most convincing facts about LENR due to deuterons of very high concentration in host metals as palladium is the measurement of the large scale minimum of the reaction probability depending on the nucleon number A of generated elements at A = 153 where a local maximum was measured. This is similar to the fission of uranium at A = 119 where the local maximum follows from the Maruhn-Greiner theory if the splitting nuclei are excited to about MeV energy. The LENR generated elements can be documented any time after the reaction by SIMS or K-shell X-ray excitation to show the very unique distribution with the local maximum. An explanation is based on the strong Debye screening of the Maxwellian deuterons within the degenerate rigid electron background especially within the swimming electron layer at the metal surface or at interfaces. The deuterons behave like neutrals at distances of about 2 picometers. They may form clusters due to soft attraction in the range above thermal energy. Clusters of 10 pm diameter may react over long time probabilities (megaseconds) with Pd nuclei leading to a double magic number compound nucleus which splits like in fission to the A = 153 element distribution.

  13. Space Experiments to Advance Beamed Energy Propulsion

    NASA Astrophysics Data System (ADS)

    Johansen, Donald G.

    2010-05-01

    High power microwave sources are now available and usable, with modification, or beamed energy propulsion experiments in space. As output windows and vacuum seals are not needed space is a natural environment for high power vacuum tubes. Application to space therefore improves reliability and performance but complicates testing and qualification. Low power communications satellite devices (TWT, etc) have already been through the adapt-to-space design cycle and this history is a useful pathway for high power devices such as gyrotrons. In this paper, space experiments are described for low earth orbit (LEO) and lunar environment. These experiments are precursors to space application for beamed energy propulsion using high power microwaves. Power generation and storage using cryogenic systems are important elements of BEP systems and also have an important role as part of BEP experiments in the space environment.

  14. Advances in computational studies of energy materials.

    PubMed

    Catlow, C R A; Guo, Z X; Miskufova, M; Shevlin, S A; Smith, A G H; Sokol, A A; Walsh, A; Wilson, D J; Woodley, S M

    2010-07-28

    We review recent developments and applications of computational modelling techniques in the field of materials for energy technologies including hydrogen production and storage, energy storage and conversion, and light absorption and emission. In addition, we present new work on an Sn2TiO4 photocatalyst containing an Sn(II) lone pair, new interatomic potential models for SrTiO3 and GaN, an exploration of defects in the kesterite/stannite-structured solar cell absorber Cu2ZnSnS4, and report details of the incorporation of hydrogen into Ag2O and Cu2O. Special attention is paid to the modelling of nanostructured systems, including ceria (CeO2, mixed Ce(x)O(y) and Ce2O3) and group 13 sesquioxides. We consider applications based on both interatomic potential and electronic structure methodologies; and we illustrate the increasingly quantitative and predictive nature of modelling in this field. PMID:20566517

  15. Recent Advancements in Nanogenerators for Energy Harvesting.

    PubMed

    Hu, Fei; Cai, Qian; Liao, Fan; Shao, Mingwang; Lee, Shuit-Tong

    2015-11-11

    Nanomaterial-based generators are a highly promising power supply for micro/nanoscale devices, capable of directly harvesting energy from ambient sources without the need for batteries. These generators have been designed within four main types: piezoelectric, triboelectric, thermoelectric, and electret effects, and consist of ZnO-based, silicon-based, ferroelectric-material-based, polymer-based, and graphene-based examples. The representative achievements, current challenges, and future prospects of these nanogenerators are discussed.

  16. Materials Challenges for Advanced Combustion and Gasification Fossil Energy Systems

    NASA Astrophysics Data System (ADS)

    Sridhar, S.; Rozzelle, P.; Morreale, B.; Alman, D.

    2011-04-01

    This special section of Metallurgical and Materials Transactions is devoted to materials challenges associated with coal based energy conversion systems. The purpose of this introductory article is to provide a brief outline to the challenges associated with advanced combustion and advanced gasification, which has the potential of providing clean, affordable electricity by improving process efficiency and implementing carbon capture and sequestration. Affordable materials that can meet the demanding performance requirements will be a key enabling technology for these systems.

  17. Advanced Combustion and Fuels; NREL (National Renewable Energy Laboratory)

    SciTech Connect

    Zigler, Brad

    2015-06-08

    Presented at the U.S. Department of Energy Vehicle Technologies Office 2015 Annual Merit Review and Peer Evaluation Meeting, held June 8-12, 2015, in Arlington, Virginia. It addresses technical barriers of inadequate data and predictive tools for fuel and lubricant effects on advanced combustion engines, with the strategy being through collaboration, develop techniques, tools, and data to quantify critical fuel physico-chemical effects to enable development of advanced combustion engines that use alternative fuels.

  18. Advanced component technologies for energy-efficient turbofan engines

    NASA Technical Reports Server (NTRS)

    Saunders, N. T.

    1980-01-01

    The paper reviews NASA's Energy Efficient Engine Project which was initiated to provide the advanced technology base for a new generation of fuel-conservative engines for introduction into airline service by the late 1980s. Efforts in this project are directed at advancing engine component and systems technologies to a point of demonstrating technology-readiness by 1984. Early results indicate high promise in achieving most of the goals established in the project.

  19. Advanced distillation saves energy and capital

    SciTech Connect

    Lestak, F.; Collins, C.

    1997-07-01

    Although new separation methods are continuously being explored, distillation remains the most frequently used separation process. It is well known that distillation is both energy intensive and inefficient. Compared to conventional column sequences, one particular configuration--the fully thermally coupled distillation column--can save significant amounts of energy by reducing thermodynamic losses. In such a setup, a number of columns (typically two) are linked together through vapor and liquid streams without reboilers or condensers between the columns. One practical application of the fully thermal coupled column has been known for a long time. However, lack of design experience and fear of operational and control problems, have prevented its widespread use to date. In addition to energy savings, divided-wall columns can save capital costs, by reducing the number of column shells, reboilers and condensers. The divided-wall column can be applied with real benefits in a variety of refinery, gas separation and chemical processes. Generally, the technology should be considered in any ternary (three-component) separation, as a possible low-cost alternative to conventional schemes. Generic guidelines for the use of divided-wall columns are discussed. The application of the divided-wall column for natural gas liquids separation is also presented.

  20. Nanostructured conductive polymers for advanced energy storage.

    PubMed

    Shi, Ye; Peng, Lele; Ding, Yu; Zhao, Yu; Yu, Guihua

    2015-10-01

    Conductive polymers combine the attractive properties associated with conventional polymers and unique electronic properties of metals or semiconductors. Recently, nanostructured conductive polymers have aroused considerable research interest owing to their unique properties over their bulk counterparts, such as large surface areas and shortened pathways for charge/mass transport, which make them promising candidates for broad applications in energy conversion and storage, sensors, actuators, and biomedical devices. Numerous synthetic strategies have been developed to obtain various conductive polymer nanostructures, and high-performance devices based on these nanostructured conductive polymers have been realized. This Tutorial review describes the synthesis and characteristics of different conductive polymer nanostructures; presents the representative applications of nanostructured conductive polymers as active electrode materials for electrochemical capacitors and lithium-ion batteries and new perspectives of functional materials for next-generation high-energy batteries, meanwhile discusses the general design rules, advantages, and limitations of nanostructured conductive polymers in the energy storage field; and provides new insights into future directions.

  1. The scission point configuration of fissioning nuclei

    NASA Astrophysics Data System (ADS)

    Ivanyuk, Fedir

    2016-06-01

    We define the optimal shape which fissioning nuclei attain just before the scission and calculate the deformation energy as function of the mass asymmetry at the scission point. The calculated deformation energy is used in quasi-static approximation for the estimation of mass distribution, total kinetic and excitation energy of fission fragments, and the total number of prompt neutrons. The calculated results reproduce rather well the experimental data on the position of the peaks in the mass distribution of fission fragments, the total kinetic and excitation energy of fission fragments. The calculated value of neutron multiplicity is somewhat larger than experimental results. The saw-tooth structure of neutron multiplicity is qualitatively reproduced.

  2. Advanced beamed-energy and field propulsion concepts

    NASA Technical Reports Server (NTRS)

    Myrabo, L. N.

    1983-01-01

    Specific phenomena which might lead to major advances in payload, range and terminal velocity of very advanced vehicle propulsion are studied. The effort focuses heavily on advanced propulsion spinoffs enabled by current government-funded investigations in directed-energy technology: i.e., laser, microwave, and relativistic charged particle beams. Futuristic (post-year 2000) beamed-energy propulsion concepts which indicate exceptional promise are identified and analytically investigated. The concepts must be sufficiently developed to permit technical understanding of the physical processes involved, assessment of the enabling technologies, and evaluation of their merits over conventional systems. Propulsion concepts that can be used for manned and/or unmanned missions for purposes of solar system exploration, planetary landing, suborbital flight, transport to orbit, and escape are presented. Speculations are made on the chronology of milestones in beamed-energy propulsion development, such as in systems applications of defense, satellite orbit-raising, global aerospace transportation, and manned interplanetary carriers.

  3. Advanced Functional Materials for Energy Related Applications

    NASA Astrophysics Data System (ADS)

    Sasan, Koroush

    The current global heavy dependency on fossil fuels gives rise to two critical problems: I) fossil fuels will be depleted in the near future; II) the release of green house gas CO2 generated by the combustion of fossil fuels contributes to global warming. To potentially address both problems, this dissertation documents three primary areas of investigation related to the development of alternative energy sources: electrocatalysts for fuel cells, photocatalysts for hydrogen generation, and photoreduction catalysts for converting CO2 to CH4. Fuel cells could be a promising source of alternative energy. Decreasing the cost and improving the durability and power density of Pt/C as a catalyst for reducing oxygen are major challenges for developing fuel cells. To address these concerns, we have synthesized a Nitrogen-Sulfur-Iron-doped porous carbon material. Our results indicate that the synthesized catalyst exhibits not only higher current density and stability but also higher tolerance to crossover chemicals than the commercial Pt/C catalyst. More importantly, the synthetic method is simple and inexpensive. Using photocatalysts and solar energy is another potential alternative solution for energy demand. We have synthesized a new biomimetic heterogeneous photocatalyst through the incorporation of homogeneous complex 1 [(i-SCH 2)2NC(O)C5H4N]-Fe2(CO) 6] into the highly robust zirconium-porphyrin based metal-organic framework (ZrPF). As photosensitizer ZrPF absorbs the visible light and produces photoexcited electrons that can be transferred through axial covalent bond to di-nuclear complex 1 for hydrogen generation. Additionally, we have studied the photoreduction of CO2 to CH4 using self-doped TiO2 (Ti+3@TiO 2) as photocatalytic materials. The incorporation of Ti3+ into TiO2 structures narrows the band gap, leading to significantly increased photocatalytic activity for the reduction of CO2 into renewable hydrocarbon fuel in the presence of water vapor under visible

  4. Advanced Offshore Wind Energy - Atlantic Consortium

    SciTech Connect

    Kempton, Willett

    2015-11-04

    This project developed relationships among the lead institution, U of Delaware, wind industry participants from 11 companies, and two other universities in the region. The participating regional universities were University of Maryland and Old Dominion University. Research was carried out in six major areas: Analysis and documentation of extreme oceanic wind events & their impact on design parameters, calibration of corrosivity estimates measured on a coastal turbine, measurment and modeling of tower structures, measurement and modeling of the tribology of major drive components, and gearbox conditioning monitoring using acoustic sensors. The project also had several educational goals, including establishing a course in wind energy and training graduate students. Going beyond these goals, three new courses were developed, a graduate certificate program in wind power was developed and approved, and an exchange program in wind energy was established with Danish Technical University. Related to the installation of a Gamesa G90 turbine on campus and a Gamesa-UD research program established in part due to this award, several additional research projects have been carried out based on mutual industry-university interests, and funded by turbine revenues. This award and the Gamesa partnership have jointly led to seven graduate students receiving full safety and climb training, to become “research climbers” as part of their wind power training, and contributing to on-turbine research. As a result of the educational program, already six graduate students have taken jobs in the US wind industry.

  5. Dual-fission chamber and neutron beam characterization for fission product yield measurements using monoenergetic neutrons

    NASA Astrophysics Data System (ADS)

    Bhatia, C.; Fallin, B.; Gooden, M. E.; Howell, C. R.; Kelley, J. H.; Tornow, W.; Arnold, C. W.; Bond, E. M.; Bredeweg, T. A.; Fowler, M. M.; Moody, W. A.; Rundberg, R. S.; Rusev, G.; Vieira, D. J.; Wilhelmy, J. B.; Becker, J. A.; Macri, R.; Ryan, C.; Sheets, S. A.; Stoyer, M. A.; Tonchev, A. P.

    2014-09-01

    A program has been initiated to measure the energy dependence of selected high-yield fission products used in the analysis of nuclear test data. We present out initial work of neutron activation using a dual-fission chamber with quasi-monoenergetic neutrons and gamma-counting method. Quasi-monoenergetic neutrons of energies from 0.5 to 15 MeV using the TUNL 10 MV FM tandem to provide high-precision and self-consistent measurements of fission product yields (FPY). The final FPY results will be coupled with theoretical analysis to provide a more fundamental understanding of the fission process. To accomplish this goal, we have developed and tested a set of dual-fission ionization chambers to provide an accurate determination of the number of fissions occurring in a thick target located in the middle plane of the chamber assembly. Details of the fission chamber and its performance are presented along with neutron beam production and characterization. Also presented are studies on the background issues associated with room-return and off-energy neutron production. We show that the off-energy neutron contribution can be significant, but correctable, while room-return neutron background levels contribute less than <1% to the fission signal.

  6. Event-by-event fission simulation code, generates complete fission events

    2013-04-01

    FREYA is a computer code that generates complete fission events. The output includes the energy and momentum of these final state particles: fission products, prompt neutrons and prompt photons. The version of FREYA that is to be released is a module for MCNP6.

  7. New approximations to the energy dependences of the total cross sections for the proton-induced fission of {sup 197}Au, {sup 203}Tl, {sup nat}Pb, and {sup 209}Bi nuclei

    SciTech Connect

    Vaishnene, L. A.; Vovchenko, V. G.; Gavrikov, Yu. A.; Murzin, V. I.; Polyakov, V. V.; Tverskoi, M. G.; Fedorov, O. Ya.; Chestnov, Yu. A. Shvedchikov, A. V.; Shchetkovskii, A. I.

    2011-01-15

    The total cross sections for {sup 197}Au and {sup 203}Tl fission induced by protons of energy varied from about 200 to 1000 MeV with a step of about 100 MeV are measured. New approximations to the energy dependences of the cross sections for the proton-induced fission of {sup 197}Au, {sup 203}Tl, natPb, and {sup 209}Bi nuclei are presented and discussed. For all of these nuclei, exponential functions are used as approximations.

  8. Fission of 232Th in a spallation neutron field

    NASA Astrophysics Data System (ADS)

    Yurevich, V. I.; Nikolaev, V. A.; Yakovlev, R. M.

    2016-03-01

    The spatial distributions of thorium fission reaction rate in a spallation neutron field of thick lead target bombarded by protons or deuterons with energy between 1.0 and 3.7 GeV were measured. Approximately a linear dependence of the thorium fission rate on the beam energy is observed. The mean fission cross section of 232Th <σ f > ≈ 123 mb and it does not depend on energy and type of the beam particles.

  9. Recent advances in statistical energy analysis

    NASA Technical Reports Server (NTRS)

    Heron, K. H.

    1992-01-01

    Statistical Energy Analysis (SEA) has traditionally been developed using modal summation and averaging approach, and has led to the need for many restrictive SEA assumptions. The assumption of 'weak coupling' is particularly unacceptable when attempts are made to apply SEA to structural coupling. It is now believed that this assumption is more a function of the modal formulation rather than a necessary formulation of SEA. The present analysis ignores this restriction and describes a wave approach to the calculation of plate-plate coupling loss factors. Predictions based on this method are compared with results obtained from experiments using point excitation on one side of an irregular six-sided box structure. Conclusions show that the use and calculation of infinite transmission coefficients is the way forward for the development of a purely predictive SEA code.

  10. Measurements of yields of fission products in the reaction of {sup 238}U with high-energy p, d and n beams

    SciTech Connect

    Nolen, J.A.; Ahmad, I.; Back, B.B.

    1995-08-01

    An experiment was performed at the Michigan State University cyclotron to determine the yields of neutron-rich fission products in the reaction of {sup 238}U with 100-MeV neutrons, 200-MeV deuterons and 200-MeV protons. Several 1-mm-thick {sup 238}U foils were irradiated for 100-second intervals sequentially for each configuration and the ten spectra were added for higher statistics. The three successive spectra, each for a 40 s period, were accumulated for each sample. Ten foils were irradiated. Successive spectra allowed us to determine approximate half-lives of the gamma peaks. Several arrangements, which were similar to the setup we plan to use in our radioactive beam proposal, were used for the production of fission products. For the high-energy neutron irradiation, U foils were placed after a 5-inch-long, 1-inch-diameter Be cylinder which stopped the 200-MeV deuteron beam generating 100-MeV neutrons. Arrangements for deuteron irradiation included direct irradiation of U foils, placing U foils after different lengths of (0.5 inch, 1.0 inch and 1.5 inch) 2-inch diameter U cylinder. Since the deuteron range in uranium is 17 mm, some of the irradiations were due to the secondary neutrons from the deuteron-induced fission of U. Similar arrangements were also used for the 200-MeV proton irradiation of the {sup 238}U foils. In all cases, several neutron-rich fission products were identified and their yields determined. In particular, we were able to observe Sn in all the runs and determine its yield. The data show that with our proposed radioactive device we will be able to produce more than 10{sup 12} {sup 132}Sn atoms per second in the target. Assuming an overall efficiency of 1 %, we will be able to deliver one particle nanoampere of {sup 132}Sn beam at a target location. Detailed analysis of the {gamma}-ray spectra is in progress.

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

    SciTech Connect

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

    2012-01-02

    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

  12. Our 50-year odyssey with fission: Summary

    SciTech Connect

    Nix, J.R.

    1989-01-01

    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.

  13. Fusion-fission hybrids for nuclear waste transmutation : a synergistic step between Gen-IV fission and fusion reactors.

    SciTech Connect

    Olson, Craig Lee; Mehlhorn, Thomas Alan; Cipiti, Benjamin B.; Rochau, Gary Eugene

    2007-09-01

    Energy demand and GDP per capita are strongly correlated, while public concern over the role of energy in climate change is growing. Nuclear power plants produce 16% of world electricity demands without greenhouse gases. Generation-IV advanced nuclear energy systems are being designed to be safe and economical. Minimizing the handling and storage of nuclear waste is important. NIF and ITER are bringing sustainable fusion energy closer, but a significant gap in fusion technology development remains. Fusion-fission hybrids could be a synergistic step to a pure fusion economy and act as a technology bridge. We discuss how a pulsed power-driven Z-pinch hybrid system producing only 20 MW of fusion yield can drive a sub-critical transuranic blanket that transmutes 1280 kg of actinide wastes per year and produces 3000 MW. These results are applicable to other inertial and magnetic fusion energy systems. A hybrid system could be introduced somewhat sooner because of the modest fusion yield requirements and can provide both a safe alternative to fast reactors for nuclear waste transmutation and a maturation path for fusion technology. The development and demonstration of advanced materials that withstand high-temperature, high-irradiation environments is a fundamental technology issue that is common to both fusion-fission hybrids and Generation-IV reactors.

  14. Energy intensity, electricity consumption, and advanced manufacturing-technology usage

    SciTech Connect

    Doms, M.E.; Dunne, T.

    1995-07-01

    This article reports on the relationship between the usage of advanced manufacturing technologies (AMTs) and energy consumption patterns in manufacturing plants. Using data from the Survey of Manufacturing Technology and the 1987 Census of Manufactures, we model the energy intensity and the electricity intensity of plants as functions of AMT usage and plant age. The main findings are that plants that utilize AMTs are less-energy intensive than plants not using AMTs, but consume proportionately more electricity as a fuel source. Additionally, older plants are generally more energy intensive and rely on fossil fuels to a greater extent than younger plants. 25 refs., 3 tabs.

  15. Multimodal Fission in Heavy-Ion Induced Reactions

    SciTech Connect

    Pokrovskiy, I. V.; Bogachev, A. A.; Iitkis, M. G.; Iitkis, J. M.; Kondratiev, N. A.; Kozulin, E. M.; Dorvaux, O.; Rowley, N.; Schmitt, Ch.; Stuttge, L.

    2006-08-14

    Mass, energy and folding angle distributions of the fission fragments as well as multiplicities of neutron and gamma-quanta emissions accompanying the fission process were measured for fission of 226Th, 227Pa and 234Pu compound nuclei produced in reactions with 18O and 26Mg projectiles over a wide energy range. Data were analyzed with respect to the presence of fission modes. Asymmetric fission was observed even at very high initial excitation for all the measured systems. The so-called fission mode S1 (caused by the proton shell Z{approx}50 and neutron shell N{approx}82 in heavy fragment) was found to be dominant in asymmetric fission of 234Pu. Reactions with not full linear momentum transfer were observed in the folding spectra for all the measured systems.

  16. Advanced Energy Storage Management in Distribution Network

    SciTech Connect

    Liu, Guodong; Ceylan, Oguzhan; Xiao, Bailu; Starke, Michael R; Ollis, T Ben; King, Daniel J; Irminger, Philip; Tomsovic, Kevin

    2016-01-01

    With increasing penetration of distributed generation (DG) in the distribution networks (DN), the secure and optimal operation of DN has become an important concern. In this paper, an iterative mixed integer quadratic constrained quadratic programming model to optimize the operation of a three phase unbalanced distribution system with high penetration of Photovoltaic (PV) panels, DG and energy storage (ES) is developed. The proposed model minimizes not only the operating cost, including fuel cost and purchasing cost, but also voltage deviations and power loss. The optimization model is based on the linearized sensitivity coefficients between state variables (e.g., node voltages) and control variables (e.g., real and reactive power injections of DG and ES). To avoid slow convergence when close to the optimum, a golden search method is introduced to control the step size and accelerate the convergence. The proposed algorithm is demonstrated on modified IEEE 13 nodes test feeders with multiple PV panels, DG and ES. Numerical simulation results validate the proposed algorithm. Various scenarios of system configuration are studied and some critical findings are concluded.

  17. AEDOT technology. [Advanced Energy Design and Operation Technologies (AEDOT)

    SciTech Connect

    Shankle, D.L.

    1993-03-01

    Most commercial buildings designed today will use more energy and cost more to operate and maintain than necessary. If energy performance were considered early in building design, 30% to 60% of the energy now used in new commercial buildings could be saved cost-effectively. However, most building design teams do not adequately consider the energy impacts of design decisions to achieve these savings; the tools for doing so simply do not yet exist. Computer technology can help design teams consider energy performance as an integral part of the design process. This technology could enable designers to produce much more energy-efficient buildings without increasing the costs of building design. Recognizing this, the US Department of Energy (DOE) has initiated the Advanced Energy Design and Operation Technologies (AEDOT) project, led by Pacific Northwest Laboratory (PNL). The aim of the project is to develop advanced computer-based technologies that will help designers take advantage of these potentially large energy savings. The success of the AEDOT project depends largely on the ability to develop energy design-support tools that can be integrated into comprehensive building design environments so that all parts of the design process willbe supported. Energy, just one consideration among many in building design, must be considered in a context that includes visual, acoustic, and structural aspects; accessibility; thermal comfort; indoor air quality; cost; and other factors associated with the quality, acceptability, and performance of a building. Advanced computer-aided design support environments will need to integrate tools from many different domains and provide access to the vast amounts of data that designers need to apply these tools and to make informed decisions.

  18. A new design of fission detector for prompt fission neutron investigation

    NASA Astrophysics Data System (ADS)

    Zeynalov, Sh.; Zeynalova, O.; Nazarenko, M. A.; Hambsch, F.-J.; Oberstedt, S.

    2012-10-01

    In this work we report recent achievements in design of twin back-to-back ionization chamber (TIC) for fission fragment (FF) mass and kinetic energy spectroscopy. Correlated FF kinetic energies, their masses and the angle of the fission axes in 3D Cartesian coordinates can be determined from analysis of the heights and shapes of the pulses induced by the fission fragments on the anodes of TIC. Anodes of TIC were designed as consisting of isolated strips each having independent electronic circuitry and special multi-channel pulse processing apparatus. Mathematical algorithms were provided along with formulae derived for fission axis angles determination. It was shown how the point of fission fragments origin on the target plane may be determined using the same measured data. The last feature made the TIC a rather powerful tool for prompt fission neutron (PFN) emission investigation in event by event analysis of individual fission reactions from non point fissile source. Position sensitive neutron induced fission detector for neutron imaging applications with both thermal and low energy neutrons was found as another possible implementation of the designed TIC.

  19. Spontaneous fission of the heaviest elements

    SciTech Connect

    Hoffman, D.C.

    1989-04-01

    Although spontaneous fission was discovered in /sup 238/U in 1940, detailed studies of the process were first made possible in the 1960's with the availability of milligram quantities of /sup 252/Cf. The advent of solid-state detectors made it possible to perform measurements of coincident fission fragments from even very short-lived spontaneous fission activities or those available in only very small quantities. Until 1971 it was believed that the main features of the mass and kinetic-energy distributions were essentially the same as those for thermal neutron-induced fission and that all low-energy fission proceeded via asymmetric mass division with total kinetic energies which could be derived by linear extrapolation from those of lighter elements. In 1971, measurements of /sup 257/Fm showed an increase in symmetric mass division with anomalously high TKE's. Subsequent experiments showed that in /sup 258/Fm and /sup 259/Fm, the most probable mass split was symmetric with very high total kinetic energy. Measurements for the heavier elements have shown symmetric mass distributions with both high and low total kinetic energies. Recent results for spontaneous fission properties of the heaviest elements are reviewed and compared with theory. 31 refs., 8 figs., 1 tab.

  20. Fission studies of secondary beams from relativistic uranium projectiles: The proton even-odd effect in fission fragment charge yields

    SciTech Connect

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

    1999-09-02

    Nuclear-charge yields of fragments produced by fission of neutron-deficient isotopes of uranium, protactinium, actinium, and radium have been measured. These radioactive isotopes were produced as secondary beams, and electromagnetic fission was induced in a lead target with an average excitation energy around 11 MeV. The local even-odd effect in symmetric and in asymmetric fission of thorium isotopes is found to be independent of Z{sup 2}/A. The charge yields of the fission fragments of the odd-Z fissioning protactinium and actinium show a pronounced even-odd effect. In asymmetric fission the unpaired proton predominantly sticks to the heavy fragment. A statistical model based on the single-particle level density at the Fermi energy is able to reproduce the overall trend of the local even-odd effects both in even-Z and odd-Z fissioning systems.

  1. Fifty years with nuclear fission. Volume 1

    SciTech Connect

    Behrens, J.W.; Carlson, A.D.

    1989-12-31

    The news of the discovery of nuclear fission, by Otto Hahn and Fritz Strassmann in Germany, was brought to the United States by Niels Bohr in January 1939. Since its discovery, the United States, and the world for that matter, has never been the same. It therefore seemed appropriate to acknowledge the fifieth anniversary of its discovery by holding a topical meeting entitled, ``Fifty Years with Nuclear Fission,`` in the United States during the year 1989. The objective of the meeting was to bring together pioneers of the nuclear industry and other scientists and engineers to report on reminiscences of the past and on the more recent development in fission science and technology. The conference highlighted the early pioneers of the nuclear industry by dedicated a full day (April 26), consisting of two plenary sessions, at the National Academy of Sciences (NAS) in Washington, DC. More recent developments in fission science and technology in addition to historical reflections were topics for two fully days of sessions (April 27 and 28) at the main site of the NIST in Gaithersburg, Maryland. The wide range of topics covered in this Volume 1 by this topical meeting included plenary invited, and contributed sessions entitled: Preclude to the First Chain Reaction -- 1932 to 1942; Early Fission Research -- Nuclear Structure and Spontaneous Fission; 50 Years of Fission, Science, and Technology; Nuclear Reactors, Secure Energy for the Future; Reactors 1; Fission Science 1; Safeguards and Space Applications; Fission Data; Nuclear Fission -- Its Various Aspects; Theory and Experiments in Support of Theory; Reactors and Safeguards; and General Research, Instrumentation, and By-Product. The individual papers have been cataloged separately.

  2. A multiple parallel-plate avalanche counter for fission-fragment detection

    NASA Astrophysics Data System (ADS)

    Wu, C. Y.; Henderson, R. A.; Haight, R. C.; Lee, H. Y.; Taddeucci, T. N.; Bucher, B.; Chyzh, A.; Devlin, M.; Fotiades, N.; Kwan, E.; O'Donnell, J. M.; Perdue, B. A.; Ullmann, J. L.

    2015-09-01

    A new low-mass multiple gas-filled parallel-plate avalanche counter for the fission-fragment detection has been developed to mark the fission occurrence in measurements of the prompt fission neutron energy spectrum as a function of incident neutron energy. It was used successfully for the neutron-induced fission of 235U and 239Pu with a total mass near 100 mg each and the spontaneous fission of 252Cf. Both the incident neutron energy and the prompt fission neutron energy are measured by using the time-of-flight method. The design and performance of this avalanche counter are described.

  3. Neutronic Model of a Mirror Based Fusion-Fission Hybrid for the Incineration of Spent Nuclear Fuel and with Potential for Energy Amplification

    NASA Astrophysics Data System (ADS)

    Noack, Klaus; Moiseenko, V. E.; Agren, O.; Hagnestall, A.

    2010-11-01

    In the last decade the Georgia Institute of Technology (Georgia Tech) published several design concepts of tokamak based fusion-fission hybrids which use solid fuels consisting of transuranic elements of the spent nuclear fuel from Light-Water-Reactors. The objectives of the hybrids are the incineration of the transuranic elements and an additional net energy production under the condition of tritium self-sufficiency. The present paper presents a preliminary scientific design of the blanket of a mirror based hybrid which was derived from the results of Monte Carlo neutron transport calculations. The main operation parameters of two hybrid options were specified. One is the analog to Georgia Techs first version of a ``fusion transmutation of waste reactor'' (FTWR) and the other is a possible near-term option which requires minimal fusion power. The latter version shows considerably better performance parameters.

  4. Analysis of linear energy transfers and quality factors of charged particles produced by spontaneous fission neutrons from 252Cf and 244Pu in the human body.

    PubMed

    Endo, Akira; Sato, Tatsuhiko

    2013-04-01

    Absorbed doses, linear energy transfers (LETs) and quality factors of secondary charged particles in organs and tissues, generated via the interactions of the spontaneous fission neutrons from (252)Cf and (244)Pu within the human body, were studied using the Particle and Heavy Ion Transport Code System (PHITS) coupled with the ICRP Reference Phantom. Both the absorbed doses and the quality factors in target organs generally decrease with increasing distance from the source organ. The analysis of LET distributions of secondary charged particles led to the identification of the relationship between LET spectra and target-source organ locations. A comparison between human body-averaged mean quality factors and fluence-averaged radiation weighting factors showed that the current numerical conventions for the radiation weighting factors of neutrons, updated in ICRP103, and the quality factors for internal exposure are valid.

  5. Mickey Leland Energy Fellowship Report: Development of Advanced Window Coatings

    SciTech Connect

    Bolton, Ladena A.; Alvine, Kyle J.; Schemer-Kohrn, Alan L.

    2014-08-05

    Advanced fenestration technologies for light and thermal management in building applications are of great recent research interest for improvements in energy efficiency. Of these technologies, there is specific interest in advanced window coating technologies that have tailored control over the visible and infrared (IR) scattering into a room for both static and dynamic applications. Recently, PNNL has investigated novel subwavelength nanostructured coatings for both daylighting, and IR thermal management applications. Such coatings rese still in the early stages and additional research is needed in terms of scalable manufacturing. This project investigates aspects of a potential new methodology for low-cost scalable manufacture of said subwavelength coatings.

  6. Center for Advanced Energy Studies (CAES) Strategic Plan

    SciTech Connect

    Kevin Kostelnik; Keith Perry

    2007-07-01

    Twenty-first century energy challenges include demand growth, national energy security, and global climate protection. The Center for Advanced Energy Studies (CAES) is a public/private partnership between the State of Idaho and its academic research institutions, the federal government through the U.S. Department of Energy (DOE) and the Idaho National Laboratory (INL) managed by the Battelle Energy Alliance (BEA). CAES serves to advance energy security for our nation by expanding the educational opportunities at the Idaho universities in energy-related areas, creating new capabilities within its member institutions, and delivering technological innovations leading to technology-based economic development for the intermountain region. CAES has developed this strategic plan based on the Balanced Scorecard approach. A Strategy Map (Section 7) summarizes the CAES vision, mission, customers, and strategic objectives. Identified strategic objectives encompass specific outcomes related to three main areas: Research, Education, and Policy. Technical capabilities and critical enablers needed to support these objectives are also identified. This CAES strategic plan aligns with and supports the strategic objectives of the four CAES institutions. Implementation actions are also presented which will be used to monitor progress towards fulfilling these objectives.

  7. Simultaneous measurement of (n, γ) and (n, fission) cross sections with the DANCE 4π BaF 2 array

    NASA Astrophysics Data System (ADS)

    Bredeweg, T. A.; Fowler, M. M.; Becker, J. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R. C.; Esch, E.-I.; Ethvignot, T.; Granier, T.; Jandel, M.; Macri, R. A.; O'Donnell, J. M.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Wu, C. Y.

    2007-08-01

    We have recently begun a program of high precision measurements of the key production and destruction reactions of important radiochemical diagnostic isotopes, including several isotopes of uranium, plutonium and americium. The detector for advanced neutron capture experiments (DANCE), a 4π BaF2 array located at the Los Alamos Neutron Science Center, will be used to measure the neutron capture cross sections for most of the isotopes of interest. However, neutron capture measurements on many of the actinides are complicated by the presence of prompt γ-rays arising from low energy neutron-induced fission, which competes with neutron capture to varying degrees. Previous measurements of 235U using the DANCE array have shown that we can partially resolve capture from fission events based on total γ-ray calorimetry (i.e. total γ-ray energy versus γ-ray multiplicity). The addition of a dedicated fission-tagging detector to the DANCE array has greatly improved our ability to separate these two competing processes. In addition to higher quality neutron capture data, the addition of a fission-tagging detector offers a means to determine the capture-to-fission ratio (σγ/σf) in a single measurement, which should reduce the effect of systematic uncertainties. We are currently using a dual parallel-plate avalanche counter (PPAC) with the target material electro-deposited directly on the center cathode foil. This design provides a high efficiency for detecting fission fragments and allows loading of pre-assembled target/detector assemblies into the neutron beam line at DANCE. Results from tests of the fission-tag detector, as well as preliminary results from measurements on 235U and 252Cf that utilized the fission-tag detector will be presented.

  8. Advanced energy systems and technologies - National R and D programme

    NASA Astrophysics Data System (ADS)

    Lund, P. D.

    1992-08-01

    The energy R and D in Finland is accomplished through the energy research programs of the Ministry of Trade and Industry. Today there are some 12 R and D programs in operation covering the various aspects of the energy sector. The NEMO-program deals with advanced new energy technologies and systems. The NEMO-program was launched in 1988 and it ends at the end of 1992. Helsinki University of Technology has been responsible for the coordination and most of the universities, research centers, and companies on new advanced energy technologies have been involved in the realization of NEMO. The objectives of the program have been to assess the potential of new technologies in the Finnish energy supply system, encourage and support businesses, and to create necessary research tradition in Finland. At the beginning in year 1988, several new technologies were included, but as the knowledge has increased, focusing on the most promising fields has taken place. Wind and solar energy show the best promises in respect to business activities and possibilities for utilization in Finland. Energy storage some other advanced technologies such as fuel cells and hydrogen technologies represented in the NEMO-program have an important role, but the commercial applications lie more distant in the future. The NEMO-program has reached its objectives. The international evaluation in fall 1990 gave very positive feedback and the scientific quality of the work was found good. At the same time, the contents was still focused more on commercial applications to support national industries in the field. The descriptions of the ongoing NEMO research projects are included in this report.

  9. Fifty years of nuclear fission: Nuclear data and measurements series

    SciTech Connect

    Lynn, J.E.

    1989-06-01

    This report is the written version of a colloquium first presented at Argonne National Laboratory in January 1989. The paper begins with an historical preamble about the events leading to the discovery of nuclear fission. This leads naturally to an account of early results and understanding of the fission phenomena. Some of the key concepts in the development of fission theory are then discussed. The main theme of this discussion is the topography of the fission barrier, in which the interplay of the liquid-drop model and nucleon shell effects lead to a wide range of fascinating phenomena encompassing metastable isomers, intermediate-structure effects in fission cross-sections, and large changes in fission product properties. It is shown how study of these changing effects and theoretical calculations of the potential energy of the deformed nucleus have led to broad qualitative understanding of the nature of the fission process. 54 refs., 35 figs.

  10. A transferable model for singlet-fission kinetics.

    PubMed

    Yost, Shane R; Lee, Jiye; Wilson, Mark W B; Wu, Tony; McMahon, David P; Parkhurst, Rebecca R; Thompson, Nicholas J; Congreve, Daniel N; Rao, Akshay; Johnson, Kerr; Sfeir, Matthew Y; Bawendi, Moungi G; Swager, Timothy M; Friend, Richard H; Baldo, Marc A; Van Voorhis, Troy

    2014-06-01

    Exciton fission is a process that occurs in certain organic materials whereby one singlet exciton splits into two independent triplets. In photovoltaic devices these two triplet excitons can each generate an electron, producing quantum yields per photon of >100% and potentially enabling single-junction power efficiencies above 40%. Here, we measure fission dynamics using ultrafast photoinduced absorption and present a first-principles expression that successfully reproduces the fission rate in materials with vastly different structures. Fission is non-adiabatic and Marcus-like in weakly interacting systems, becoming adiabatic and coupling-independent at larger interaction strengths. In neat films, we demonstrate fission yields near unity even when monomers are separated by >5 Å. For efficient solar cells, however, we show that fission must outcompete charge generation from the singlet exciton. This work lays the foundation for tailoring molecular properties like solubility and energy level alignment while maintaining the high fission yield required for photovoltaic applications. PMID:24848234

  11. A transferable model for singlet-fission kinetics

    NASA Astrophysics Data System (ADS)

    Yost, Shane R.; Lee, Jiye; Wilson, Mark W. B.; Wu, Tony; McMahon, David P.; Parkhurst, Rebecca R.; Thompson, Nicholas J.; Congreve, Daniel N.; Rao, Akshay; Johnson, Kerr; Sfeir, Matthew Y.; Bawendi, Moungi G.; Swager, Timothy M.; Friend, Richard H.; Baldo, Marc A.; van Voorhis, Troy

    2014-06-01

    Exciton fission is a process that occurs in certain organic materials whereby one singlet exciton splits into two independent triplets. In photovoltaic devices these two triplet excitons can each generate an electron, producing quantum yields per photon of >100% and potentially enabling single-junction power efficiencies above 40%. Here, we measure fission dynamics using ultrafast photoinduced absorption and present a first-principles expression that successfully reproduces the fission rate in materials with vastly different structures. Fission is non-adiabatic and Marcus-like in weakly interacting systems, becoming adiabatic and coupling-independent at larger interaction strengths. In neat films, we demonstrate fission yields near unity even when monomers are separated by >5 Å. For efficient solar cells, however, we show that fission must outcompete charge generation from the singlet exciton. This work lays the foundation for tailoring molecular properties like solubility and energy level alignment while maintaining the high fission yield required for photovoltaic applications.

  12. Membrane Fission: Model for Intermediate Structures

    PubMed Central

    Kozlovsky, Yonathan; Kozlov, Michael M.

    2003-01-01

    Membrane budding-fission is a fundamental process generating intracellular carriers of proteins. Earlier works were focused only on formation of coated buds connected to the initial membrane by narrow membrane necks. We present the theoretical analysis of the whole pathway of budding-fission, including the crucial stage where the membrane neck undergoes fission and the carrier separates from the donor membrane. We consider two successive intermediates of the reaction: 1), a constricted membrane neck coming out of aperture of the assembling protein coat, and 2), hemifission intermediate resulting from self-fusion of the inner monolayer of the neck, while its outer monolayer remains continuous. Transformation of the constricted neck into the hemifission intermediate is driven by the membrane stress produced in the neck by the protein coat. Although apparently similar to hemifusion, the fission is predicted to have an opposite dependence on the monolayer spontaneous curvature. Analysis of the further stages of the process demonstrates that in all practically important cases the hemifission intermediate decays spontaneously into two separate membranes, thereby completing the fission process. We formulate the “job description” for fission proteins by calculating the energy they have to deliver and the radii of the protein coat aperture which have to be reached to drive the fission process. PMID:12829467

  13. USAF advanced terrestrial energy study. Volume 2: Technology handbook

    NASA Astrophysics Data System (ADS)

    Daniels, E. J.; Yudow, B. D.; Donakowski, T. D.

    1983-04-01

    This report presents the results of the USAF Advanced Terrestrial Energy Study. The objective of that study was to develop a data base of key parameters of selected energy conversion and energy storage technologies. The data base includes present and expected (through 2000) performance goals of the systems. The data base was established through an extensive literature search, surveys of manufacturers and researchers, and statistical and qualitative analyses of the available input data. The results of the study are reported in four documents: (1) Project Summary; (2) Technology Handbook; (3) Parameter Survey; (4) Analysis, Data, Bibliography. Contents (Volume II): Diesels, Gas Turbines, Stirlings, Organic Rankine Cycle, Fuel Cells, Photovoltaic Energy Conversion System, Wind Turbines, Batteries, Thermal Energy Storage System.

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

    SciTech Connect

    Hall, H.L. . Dept. of Chemistry)

    1989-10-23

    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.

  15. Ionization Chamber for Prompt Fission Neutron Investigations

    NASA Astrophysics Data System (ADS)

    Zeynalov, Sh.; Zeynalova, O.; Hambsch, F.-J.; Sedyshev, P.; Shvetsov, V.

    In this work we report recent achievements in design of twin back-to-back ionization chamber (TIC) for fission fragment (FF) mass and kinetic energy measurement. Correlated FF kinetic energies, their masses and the angle of FF in respect to the axes in 3D Cartesian coordinates can be determined from analysis of the heights and shapes of the pulses induced by the fission fragments on the anodes of TIC. Anodes of TIC were designed as consisting of isolated strips each having independent electronic circuitry and special multi-channel pulse processing apparatus. Mathematical formulae provided for FF angles measured in respect to the coordinate axes. It was shown how the point of fission fragments origin on the target plane may be determined using the same measured data. The last feature made the TIC a rather powerful tool for prompt fission neutron (PFN) emission investigation in event-by-event analysis of individual fission reactions from non- point fissile source. Position sensitive neutron induced fission detector for neutron-imaging applications with both thermal and low energy neutrons was found as another possible implementation of the designed TIC.

  16. 78 FR 9446 - Advance Nanotech, Inc., Advanced ID Corp., Aeon Holdings, Inc. (n/k/a BCM Energy Partners, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ... COMMISSION Advance Nanotech, Inc., Advanced ID Corp., Aeon Holdings, Inc. (n/k/a BCM Energy Partners, Inc..., Ltd., EcoReady Corp., EnDevCo, Inc., Electronic Kourseware International, Inc., Ensign Services, Inc... accurate information concerning the securities of Advanced ID Corp. because it has not filed any...

  17. Modeling Fission Product Sorption in Graphite Structures

    SciTech Connect

    Szlufarska, Izabela; Morgan, Dane; Allen, Todd

    2013-04-08

    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

  18. The Fission Barrier Landscape

    SciTech Connect

    Phair, L.; Moretto, L. G.

    2008-04-17

    Fission excitation functions have been measured for a chain of neighboring compound nuclei from {sup 207}Po to {sup 212}Po. We present a new analysis which provides a determination of the fission barriers and ground state shell effects with nearly spectroscopic accuracy. The accuracy achieved in this analysis may lead to a future detailed exploration of the saddle mass surface and its spectroscopy.

  19. Fission Spectrum Related Uncertainties

    SciTech Connect

    G. Aliberti; I. Kodeli; G. Palmiotti; M. Salvatores

    2007-10-01

    The paper presents a preliminary uncertainty analysis related to potential uncertainties on the fission spectrum data. Consistent results are shown for a reference fast reactor design configuration and for experimental thermal configurations. However the results obtained indicate the need for further analysis, in particular in terms of fission spectrum uncertainty data assessment.

  20. Fission gas detection system

    DOEpatents

    Colburn, Richard P.

    1985-01-01

    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.

  1. Advanced Reactors Thermal Energy Transport for Process Industries

    SciTech Connect

    P. Sabharwall; S.J. Yoon; M.G. McKellar; C. Stoots; George Griffith

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as liquid fuel production, district heating, desalination, hydrogen production, and other process heat applications, etc. Some of the major technology challenges that must be overcome before the advanced reactors could be licensed on the reactor side are qualification of next generation of nuclear fuel, materials that can withstand higher temperature, improvement in power cycle thermal efficiency by going to combined cycles, SCO2 cycles, successful demonstration of advanced compact heat exchangers in the prototypical conditions, and from the process side application the challenge is to transport the thermal energy from the reactor to the process plant with maximum efficiency (i.e., with minimum temperature drop). The main focus of this study is on doing a parametric study of efficient heat transport system, with different coolants (mainly, water, He, and molten salts) to determine maximum possible distance that can be achieved.

  2. Bright fission: singlet fission into a pair of emitting states.

    PubMed

    Casanova, David

    2015-06-01

    This paper reintroduces and explores the generation of two bright states from a single photon via a singlet fission mechanism in organic materials. This particular photophysical process is labeled here as bright fission (BF). The central part of the study is devoted to set the theoretical foundations of BF by discussing possible electronic mechanisms, the role of different excited states with various physical nature, the presence of competing deactivation channels, and the possible requirements for the BF viability. In a second part, some of the properties related to BF are computationally explored in anthracene. The analysis of computed high-lying excited states identifies several optical transitions as good candidates to trigger BF in anthracene. The approximation of excitonic couplings of these high energy levels to other electronic states within the same energy range suggests possible paths to populate electronic configurations potentially able to split in two independent spin singlets, i.e. singlet-singlet states. The study also explores the electronic structure of the energetically lowest singlet-singlet states in anthracene dimers and discusses the presence of charge transfer configurations and their relation to the singlet-singlet manifold. The computational results suggest fast relaxation to the lowest singlet-singlet state, from which the excitonic fission may occur. All in all, the present work aims at motivating to pursue further efforts in the study of the BF process in organic materials.

  3. Fission of actinide nuclei using multi-nucleon transfer reactions

    NASA Astrophysics Data System (ADS)

    Léguillon, Romain; Nishio, Katsuhisa; Hirose, Kentaro; Orlandi, Riccardo; Makii, Hiroyuki; Nishinaka, Ichiro; Ishii, Tetsuro; Tsukada, Kazuaki; Asai, Masato; Chiba, Satoshi; Ohtsuki, Tsutomu; Araki, Shohei; Watanabe, Yukinobu; Tatsuzawa, Ryotaro; Takaki, Naoyuki

    2014-09-01

    We are promoting a campaign to measure fission-fragment mass distributions for neutron-rich actinide nuclei populated by transfer reactions from their ground state up to an excitation energy of several tens MeV. We thus obtain the excitation energy dependence of the mass distribution. The experiment was carried out at the 20 MV JAEA tandem facility at Tokai. We report on the data obtained in the direct reaction 18 O + 232 Th . Transfer-channels and excitation energies of the fissioning nuclei were identified using silicon dE-E detectors located at forward angle. Two fission fragments were detected in coincidence using multi-wire proportional counters. Fission fragment masses were determined by kinematic consideration. We obtained the fission fragment mass distributions for 13 nuclei from actinium to uranium and some fission barrier heights. We are promoting a campaign to measure fission-fragment mass distributions for neutron-rich actinide nuclei populated by transfer reactions from their ground state up to an excitation energy of several tens MeV. We thus obtain the excitation energy dependence of the mass distribution. The experiment was carried out at the 20 MV JAEA tandem facility at Tokai. We report on the data obtained in the direct reaction 18 O + 232 Th . Transfer-channels and excitation energies of the fissioning nuclei were identified using silicon dE-E detectors located at forward angle. Two fission fragments were detected in coincidence using multi-wire proportional counters. Fission fragment masses were determined by kinematic consideration. We obtained the fission fragment mass distributions for 13 nuclei from actinium to uranium and some fission barrier heights. Present study is supported by the Ministry of Education, Culture, Sports, Science and Technology of Japan.

  4. Advanced vehicles: Costs, energy use, and macroeconomic impacts

    NASA Astrophysics Data System (ADS)

    Wang, Guihua

    Advanced vehicles and alternative fuels could play an important role in reducing oil use and changing the economy structure. We developed the Costs for Advanced Vehicles and Energy (CAVE) model to investigate a vehicle portfolio scenario in California during 2010-2030. Then we employed a computable general equilibrium model to estimate macroeconomic impacts of the advanced vehicle scenario on the economy of California. Results indicate that, due to slow fleet turnover, conventional vehicles are expected to continue to dominate the on-road fleet and gasoline is the major transportation fuel over the next two decades. However, alternative fuels could play an increasingly important role in gasoline displacement. Advanced vehicle costs are expected to decrease dramatically with production volume and technological progress; e.g., incremental costs for fuel cell vehicles and hydrogen could break even with gasoline savings in 2028. Overall, the vehicle portfolio scenario is estimated to have a slightly negative influence on California's economy, because advanced vehicles are very costly and, therefore, the resulting gasoline savings generally cannot offset the high incremental expenditure on vehicles and alternative fuels. Sensitivity analysis shows that an increase in gasoline price or a drop in alternative fuel prices could offset a portion of the negative impact.

  5. Energy and Economic Trade Offs for Advanced Technology Subsonic Aircraft

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Wagner, R. D.

    1976-01-01

    Changes in future aircraft technology which conserve energy are studied, along with the effect of these changes on economic performance. Among the new technologies considered are laminar-flow control, composite materials with and without laminar-flow control, and advanced airfoils. Aircraft design features studied include high-aspect-ratio wings, thickness ratio, and range. Engine technology is held constant at the JT9D level. It is concluded that wing aspect ratios of future aircraft are likely to significantly increase as a result of new technology and the push of higher fuel prices. Composite materials may raise aspect radio to about 11 to 12 and practical laminar flow-control systems may further increase aspect ratio to 14 or more. Advanced technology provides significant reductions in aircraft take-off gross weight, energy consumption, and direct operating cost.

  6. 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop

    SciTech Connect

    none,

    2011-10-01

    The U.S. marine energy industry is actively pursuing development of offshore wind and marine hydrokinetic (MHK) energy systems. Experience in the wind energy sector demonstrates that new technology development requires thorough measurement and characterization of the environmental conditions prevalent at installation sites and of technology operating in the field. Presently, there are no turn-key instrumentation system solutions that meet the measurement needs of the marine energy industry. The 1st Advanced Marine Renewable Energy Instrumentation Experts Workshop brought together technical experts from government laboratories, academia, and industry representatives from marine energy, wind, offshore oil and gas, and instrumentation developers to present and discuss the instrumentation needs of the marine energy industry. The goals of the meeting were to: 1. Share the latest relevant knowledge among technical experts; 2. Review relevant state-of-the-art field measurement technologies and methods; 3. Review lessons learned from recent field deployments; 4. Identify synergies across different industries; 5. Identify gaps between existing and needed instrumentation capabilities; 6. Understand who are the leading experts; 7. Provide a forum where stakeholders from the marine energy industry could provide substantive input in the development of new marine energy field deployable instrumentation packages.

  7. Fossil Energy Advanced Research and Technology Development Materials Program

    SciTech Connect

    Cole, N.C.; Judkins, R.R.

    1992-12-01

    Objective of this materials program is to conduct R and D on materials for fossil energy applications with focus on longer-term and generic needs of the various fossil fuel technologies. The projects are organized according to materials research areas: (1) ceramics, (2) new alloys: iron aluminides, advanced austenitics and chromium niobium alloys, and (3) technology development and transfer. Separate abstracts have been prepared.

  8. Simulation Toolkit for Renewable Energy Advanced Materials Modeling

    SciTech Connect

    Sides, Scott; Kemper, Travis; Larsen, Ross; Graf, Peter

    2013-11-13

    STREAMM is a collection of python classes and scripts that enables and eases the setup of input files and configuration files for simulations of advanced energy materials. The core STREAMM python classes provide a general framework for storing, manipulating and analyzing atomic/molecular coordinates to be used in quantum chemistry and classical molecular dynamics simulations of soft materials systems. The design focuses on enabling the interoperability of materials simulation codes such as GROMACS, LAMMPS and Gaussian.

  9. Basic Research Needs for Advanced Nuclear Systems. Report of the Basic Energy Sciences Workshop on Basic Research Needs for Advanced Nuclear Energy Systems, July 31-August 3, 2006

    SciTech Connect

    Roberto, J.; Diaz de la Rubia, T.; Gibala, R.; Zinkle, S.; Miller, J.R.; Pimblott, S.; Burns, C.; Raymond, K.; Grimes, R.; Pasamehmetoglu, K.; Clark, S.; Ewing, R.; Wagner, A.; Yip, S.; Buchanan, M.; Crabtree, G.; Hemminger, J.; Poate, J.; Miller, J.C.; Edelstein, N.; Fitzsimmons, T.; Gruzalski, G.; Michaels, G.; Morss, L.; Peters, M.; Talamini, K.

    2006-10-01

    -ray sources, neutron sources, nanoscale science research centers, and supercomputers, offer the opportunity to transform and accelerate the fundamental materials and chemical sciences that underpin technology development for advanced nuclear energy systems. The fundamental challenge is to understand and control chemical and physical phenomena in multi-component systems from femto-seconds to millennia, at temperatures to 1000?C, and for radiation doses to hundreds of displacements per atom (dpa). This is a scientific challenge of enormous proportions, with broad implications in the materials science and chemistry of complex systems. New understanding is required for microstructural evolution and phase stability under relevant chemical and physical conditions, chemistry and structural evolution at interfaces, chemical behavior of actinide and fission-product solutions, and nuclear and thermomechanical phenomena in fuels and waste forms. First-principles approaches are needed to describe f-electron systems, design molecules for separations, and explain materials failure mechanisms. Nanoscale synthesis and characterization methods are needed to understand and design materials and interfaces with radiation, temperature, and corrosion resistance. Dynamical measurements are required to understand fundamental physical and chemical phenomena. New multiscale approaches are needed to integrate this knowledge into accurate models of relevant phenomena and complex systems across multiple length and time scales.

  10. High-energy diffraction microscopy at the advanced photon source

    SciTech Connect

    Lienert, U.; Li, S.; Hefferan, C.; Lind, J.; Suter, R.; Bernier, J.; Barton, N.; Brandes, M.; Mills, M.; Miller, M.; Jakobsen, B.; Pantleon, W.

    2012-02-28

    The status of the High Energy Diffraction Microscopy (HEDM) program at the 1-ID beam line of the Advanced Photon Source is reported. HEDM applies high energy synchrotron radiation for the grain and sub-grain scale structural and mechanical characterization of polycrystalline bulk materials in situ during thermomechanical loading. Case studies demonstrate the mapping of grain boundary topology, the evaluation of stress tensors of individual grains during tensile deformation and comparison to a finite element modeling simulation, and the characterization of evolving dislocation structure. Complementary information is obtained by post mortem electron microscopy on the same sample volume previously investigated by HEDM.

  11. A study of an advanced confined linear energy source

    NASA Technical Reports Server (NTRS)

    Anderson, M. C.; Heidemann, W. B.

    1971-01-01

    A literature survey and a test program to develop and evaluate an advanced confined linear energy source were conducted. The advanced confined linear energy source is an explosive or pyrotechnic X-Cord (mild detonating fuse) supported inside a confining tube capable of being hermetically sealed and retaining all products of combustion. The energy released by initiation of the X-Cord is transmitted through the support material to the walls of the confining tube causing an appreciable change in cross sectional configuration and expansion of the tube. When located in an assembly that can accept and use the energy of the tube expansion, useful work is accomplished through fracture of a structure, movement of a load, reposition of a pin, release of a restraint, or similar action. The tube assembly imparts that energy without release of debris or gases from the device itself. This facet of the function is important to the protection of men or equipment located in close proximity to the system during the time of function.

  12. The Importance of Advancing Technology to America's Energy Goals

    SciTech Connect

    Wilbanks, Thomas J; Greene, David L

    2010-05-01

    A wide range of energy technologies appears to be needed for the United States to meet its energy goals. A method is developed that relates the uncertainty of technological progress in eleven technology areas to the achievement of CO2 mitigation and reduced oil dependence. We conclude that to be confident of meeting both energy goals, each technology area must have a much better than 50/50 probability of success, that carbon capture and sequestration, biomass, battery electric or fuel cell vehicles, advanced fossil liquids, and energy efficiency technologies for buildings appear to be almost essential, and that the success of each one of the 11 technologies is important. These inferences are robust to moderate variations in assumptions.

  13. New fission-fragment detector for experiments at DANCE

    NASA Astrophysics Data System (ADS)

    Rusev, G.; Roman, A. R.; Daum, J. K.; Springs, R. K.; Bond, E. M.; Jandel, M.; Baramsai, B.; Bredeweg, T. A.; Couture, A.; Favalli, A.; Ianakiev, K. D.; Iliev, M. L.; Mosby, S.; Ullmann, J. L.; Walker, C. L.

    2015-10-01

    A fission-fragment detector based on thin scintillating films has been built to serve as a veto/trigger detector in neutron-induced fission measurements at DANCE. The fissile material is surrounded by scintillating films providing a 4 π detection of the fission fragments. The scintillation events caused by the fission fragment interactions in the films are registered with silicon photomultipliers. Design of the detector and test measurements are described. Work supported by the U.S. Department of Energy through the LANL/LDRD Program and the U.S. Department of Energy, Office of Science, Nuclear Physics under the Early Career Award No. LANL20135009.

  14. The Path to Sustainable Nuclear Energy. Basic and Applied Research Opportunities for Advanced Fuel Cycles

    SciTech Connect

    Finck, P.; Edelstein, N.; Allen, T.; Burns, C.; Chadwick, M.; Corradini, M.; Dixon, D.; Goff, M.; Laidler, J.; McCarthy, K.; Moyer, B.; Nash, K.; Navrotsky, A.; Oblozinsky, P.; Pasamehmetoglu, K.; Peterson, P.; Sackett, J.; Sickafus, K. E.; Tulenko, J.; Weber, W.; Morss, L.; Henry, G.

    2005-09-01

    The objective of this report is to identify new basic science that will be the foundation for advances in nuclear fuel-cycle technology in the near term, and for changing the nature of fuel cycles and of the nuclear energy industry in the long term. The goals are to enhance the development of nuclear energy, to maximize energy production in nuclear reactor parks, and to minimize radioactive wastes, other environmental impacts, and proliferation risks. The limitations of the once-through fuel cycle can be overcome by adopting a closed fuel cycle, in which the irradiated fuel is reprocessed and its components are separated into streams that are recycled into a reactor or disposed of in appropriate waste forms. The recycled fuel is irradiated in a reactor, where certain constituents are partially transmuted into heavier isotopes via neutron capture or into lighter isotopes via fission. Fast reactors are required to complete the transmutation of long-lived isotopes. Closed fuel cycles are encompassed by the Department of Energy?s Advanced Fuel Cycle Initiative (AFCI), to which basic scientific research can contribute. Two nuclear reactor system architectures can meet the AFCI objectives: a ?single-tier? system or a ?dual-tier? system. Both begin with light water reactors and incorporate fast reactors. The ?dual-tier? systems transmute some plutonium and neptunium in light water reactors and all remaining transuranic elements (TRUs) in a closed-cycle fast reactor. Basic science initiatives are needed in two broad areas: ? Near-term impacts that can enhance the development of either ?single-tier? or ?dual-tier? AFCI systems, primarily within the next 20 years, through basic research. Examples: Dissolution of spent fuel, separations of elements for TRU recycling and transmutation Design, synthesis, and testing of inert matrix nuclear fuels and non-oxide fuels Invention and development of accurate on-line monitoring systems for chemical and nuclear species in the nuclear

  15. Tuning of the stability and energy levels of singlet exciton fission relevant excited states of pentacenes by site-specific substitution.

    PubMed

    Shen, Li; Chen, Yuhan; Li, Xiyou; Li, Chungang

    2016-05-01

    Pentacene crystals or oligomers undergo efficient singlet exciton fission (SF) after photo-excitation, which is expected to be useful in overcoming the Shockley-Queisser theoretical limit of solar cells. However, pentacenes are extremely unstable in air due to oxidation by oxygen. In this work, we designed a group of pentacene compounds with different substituents at different positions. The energy levels of HOMO and LUMO, which are believed to be closely related to the stability of pentacene, were calculated. The relationship between the molecular structure and the stability was discussed. The driving force for SF was estimated from the difference between the energy of first singlet excited state (E(S1)) and the energy of two triplet excited state (2×E(T1)) following equation E(S1)-2E(T1). Strong electron-withdrawing groups can stabilize pentacene compounds significantly, but induce a decrease on the driving force of SF slightly. Electron-donating groups destabilize the pentacene compounds dramatically and hence the introduction of electron donating groups to pentacene is not recommended. TIPS is an ideal group to improve the stability of pentacene compounds. TIPS does not change the driving force of SF significantly. Sulfur containing groups are also efficient on stabilizing pentacene compounds. These groups increase the driving force of SF at ɑ position, and recued the driving force of SF at other positions. The results of this work provide a theoretical ground for rational design of new SF molecules based on pentacenes. PMID:27131283

  16. Tuning of the stability and energy levels of singlet exciton fission relevant excited states of pentacenes by site-specific substitution.

    PubMed

    Shen, Li; Chen, Yuhan; Li, Xiyou; Li, Chungang

    2016-05-01

    Pentacene crystals or oligomers undergo efficient singlet exciton fission (SF) after photo-excitation, which is expected to be useful in overcoming the Shockley-Queisser theoretical limit of solar cells. However, pentacenes are extremely unstable in air due to oxidation by oxygen. In this work, we designed a group of pentacene compounds with different substituents at different positions. The energy levels of HOMO and LUMO, which are believed to be closely related to the stability of pentacene, were calculated. The relationship between the molecular structure and the stability was discussed. The driving force for SF was estimated from the difference between the energy of first singlet excited state (E(S1)) and the energy of two triplet excited state (2×E(T1)) following equation E(S1)-2E(T1). Strong electron-withdrawing groups can stabilize pentacene compounds significantly, but induce a decrease on the driving force of SF slightly. Electron-donating groups destabilize the pentacene compounds dramatically and hence the introduction of electron donating groups to pentacene is not recommended. TIPS is an ideal group to improve the stability of pentacene compounds. TIPS does not change the driving force of SF significantly. Sulfur containing groups are also efficient on stabilizing pentacene compounds. These groups increase the driving force of SF at ɑ position, and recued the driving force of SF at other positions. The results of this work provide a theoretical ground for rational design of new SF molecules based on pentacenes.

  17. New experimental approaches to investigate the fission dynamics

    NASA Astrophysics Data System (ADS)

    Benlliure, J.; Rodríguez-Sánchez, J. L.; Alvarez-Pol, H.; Audouin, L.; Ayyad, Y.; Bélier, G.; Boutoux, G.; Casarejos, E.; Chatillon, A.; Cortina-Gil, D.; Gorbinet, T.; Heinz, A.; Kelić-Heil, A.; Laurent, B.; Martin, J.-F.; Paradela, C.; Pellereau, E.; Pietras, B.; Ramos, D.; Rodríguez-Tajes, C.; Rossi, D. M.; Simon, H.; Taïeb, J.; Vargas, J.; Voss, B.

    2016-07-01

    The first ever achieved full identification of both fission fragments, in atomic and mass number, made it possible to define new observables sensitive to the fission dynamics along the fission path up to the scission point. Moreover, proton-induced fission of 208Pb at high energies offers optimal conditions for the investigation of dissipative, and transient effects, because of the high-excitation energy of the fissioning nuclei, its low angular momentum, and limited shape distortion by the reaction. In this work we show that the charge distribution of the final fission fragments can constrain the ground-to-saddle dynamics while the mass distribution is sensitive to the dynamics until the scission point.

  18. Low Energy Fission of {sup 256}No, {sup 270}Sg, {sup 271}Hs and {sup 286}112 Nuclei Formed in Reactions with {sup 22}Ne and {sup 48}Ca Ions

    SciTech Connect

    Itkis, M.G.; Kondratiev, N.A.; Kozulin, E.M.; Krupa, L.; Oganessian, Yu. Ts.; Pokrovsky, I.V.; Prokhorova, E.V.; Rusanov, A. Ya.

    1999-12-31

    The fusion-fission reactions {sup 22}Ne + {sup 248}Cm and {sup 22}Ne + {sup 249}Cf were investigated at projectile energies equal to 102 and 127 MeV. Mass-energy distributions and yields are shown. Two-dimensional plots of TKE vs fragment mass are also shown for {sup 48}Ca reactions at 230 MeV with {sup 208}Pb and {sup 238}U, leading to {sup 256}No and {sup 286}112.

  19. Competition between fusion-fission and quasifission processes in the {sup 32}S+{sup 184}W reaction

    SciTech Connect

    Zhang, H. Q.; Zhang, C. L.; Lin, C. J.; Liu, Z. H.; Yang, F.; Nasirov, A. K.; Mandaglio, G.; Manganaro, M.; Giardina, G.

    2010-03-15

    The angular distributions of fission fragments for the {sup 32}S+{sup 184}W reaction at center-of-mass energies of 118.8, 123.1, 127.3, 131.5, 135.8, 141.1, and 144.4 MeV are measured. The experimental fission excitation function is obtained. The anisotropy (A{sub exp}) is found by extrapolating each fission fragment angular distribution. The measured fission cross sections of the {sup 32}S+{sup 182,184}W reaction are decomposed into fusion-fission, quasifission, and fast-fission contributions by the dinuclear system model (DNS). The angular momentum distributions of the dinuclear system and compound nucleus calculated by the DNS model are used to reproduce the experimental capture and fusion excitation functions for both reactions and quantities K{sub 0}{sup 2}, , and A{sub exp}, which characterize angular distributions of the fission products at the considered range of beam energy. The total evaporation residue excitation function for the {sup 32}S+{sup 184}W reaction calculated in the framework of the advanced statistical model is close to the available experimental data only up to about E{sub c.m.}approx =160 MeV. The underestimation of the experimental data at high excitation energies E{sub c.m.}>160 MeV is explained by the fact that the statistical model cannot reproduce the cross section of evaporation residues formed by the nonequilibrium mechanism, that is, without formation of the compound nucleus in the statistical equilibrium state.

  20. Harsh environment sensor development for advanced energy systems

    NASA Astrophysics Data System (ADS)

    Romanosky, Robert R.; Maley, Susan M.

    2013-05-01

    Highly efficient, low emission power systems have extreme conditions of high temperature, high pressure, and corrosivity that require monitoring. Sensing in these harsh environments can provide key information that directly impacts process control and system reliability. To achieve the goals and demands of clean energy, the conditions under which fossil fuels are converted into heat and power are harsh compared to traditional combustion/steam cycles. Temperatures can extend as high as 1600 Celsius (°C) in certain systems and pressures can reach as high as 5000 pounds per square inch (psi)/340 atmospheres (atm). The lack of suitable measurement technology serves as a driver for the innovations in harsh environment sensor development. Two major considerations in the development of harsh environments sensors are the materials used for sensing and the design of the sensing device. This paper will highlight the U.S. Department of Energy's, Office of Fossil Energy and National Energy Technology Laboratory's Program in advanced sensing concepts that are aimed at addressing the technology needs and drivers through the development of new sensor materials and designs capable of withstanding harsh environment conditions. Recent developments with harsh environment sensors will be highlighted and future directions towards in advanced sensing will be introduced.

  1. Low-mass fission detector for the fission neutron spectrum measurement

    SciTech Connect

    Wu, C Y; Henderson, R; Gostic, J; Haight, R C; Lee, H Y

    2010-10-20

    For the fission neutron spectrum measurement, the neutron energy is determined in a time-of-flight experiment by the time difference between the fission event and detection of the neutron. Therefore, the neutron energy resolution is directly determined by the time resolution of both neutron and fission detectors. For the fission detection, the detector needs not only a good timing response but also the tolerance of radiation damage and high {alpha}-decay rate. A parallel-plate avalanche counter (PPAC) has many advantages for the detection of heavy charged particles such as fission fragments. These include fast timing, resistance to radiation damage, and tolerance of high counting rate. A PPAC also can be tuned to be insensitive to particles, which is important for experiments with - emitting actinides. Therefore, a PPAC is an ideal detector for experiments requiring a fast and clean trigger for fission. In the following sections, the description will be given for the design and performance of a new low-mass PPAC for the fission-neutron spectrum measurements at LANL.

  2. Microscopic description of 258Fm fission dynamic with pairing

    NASA Astrophysics Data System (ADS)

    Scamps, Guillaume; Simenel, Cédric; Lacroix, Denis

    2016-05-01

    Fission dynamic remains a challenge for nuclear microscopic theories. In order to understand the dynamic of the last stage of the fission process, the time-dependent Hartree-Fock approach with BCS pairing is applied to the describe the fission of the 258Fm. A good agreement is found for the one-body observables: the total kinetic energy and the average mass asymmetry. The non-physical dependence of two-body observables with the initial shape is discussed.

  3. Fission studies with 140 MeV {alpha} particles

    SciTech Connect

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

    2009-09-15

    Binary fission induced by 140 MeV {alpha} particles has been measured for {sup nat}Ag, {sup 139}La, {sup 165}Ho, and {sup 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{sup 2}/A=24 is observed.

  4. Masters Study in Advanced Energy and Fuels Management

    SciTech Connect

    Mondal, Kanchan

    2014-12-08

    There are currently three key drivers for the US energy sector a) increasing energy demand and b) environmental stewardship in energy production for sustainability and c) general public and governmental desire for domestic resources. These drivers are also true for energy nation globally. As a result, this sector is rapidly diversifying to alternate sources that would supplement or replace fossil fuels. These changes have created a need for a highly trained workforce with a the understanding of both conventional and emerging energy resources and technology to lead and facilitate the reinvention of the US energy production, rational deployment of alternate energy technologies based on scientific and business criteria while invigorating the overall economy. In addition, the current trends focus on the the need of Science, Technology, Engineering and Math (STEM) graduate education to move beyond academia and be more responsive to the workforce needs of businesses and the industry. The SIUC PSM in Advanced Energy and Fuels Management (AEFM) program was developed in response to the industries stated need for employees who combine technical competencies and workforce skills similar to all PSM degree programs. The SIUC AEFM program was designed to provide the STEM graduates with advanced technical training in energy resources and technology while simultaneously equipping them with the business management skills required by professional employers in the energy sector. Technical training include core skills in energy resources, technology and management for both conventional and emerging energy technologies. Business skills training include financial, personnel and project management. A capstone internship is also built into the program to train students such that they are acclimatized to the real world scenarios in research laboratories, in energy companies and in government agencies. The current curriculum in the SIUC AEFM will help fill the need for training both recent

  5. Mass-asymmetric fission in the 40ca+142Nd reaction

    NASA Astrophysics Data System (ADS)

    Prasad, E.; Hinde, D. J.; Williams, E.; Dasgupta, M.; Carter, I. P.; Cook, K. J.; Jeung, D. Y.; Luong, D. H.; McNeil, S.; Palshetkar, C. S.; Rafferty, D. C.; Simenel, C.; Wakhle, A.; Ramachandran, K.; Khuyagbaatar, J.; Dullmann, Ch. E.; Lommel, B.; Kindler, B.

    2016-09-01

    Shell effects play a major role in fission. Mass-asymmetric fission observed in the spontaneous and low energy fission of actinide nuclei was explained by incorporating the fragment shell properties in liquid drop model. Asymmetric fission has also been observed in the low energy fission of neutron-deficient 180Hg nuclei in recent β-delayed fission experiments. This low-energy β-delayed fission has been explained in terms of strong shell effects in pre-scission configurations associated with the system after capture. Calculations predicted asymmetric fission for heavier Hg isotopes as well, at compound nuclear excitation energy as high as 40 MeV. To explore the evolution of fission fragment mass distribution as a function of neutron and proton numbers and also with excitation energy, fission fragment mass distributions have been measured for the 40Ca+142Nd reaction forming the compound nucleus 182Hg at energies around the capture barrier, using the Heavy Ion Accelerator Facility and CUBE spectrometer at the Australian National University. Mass-asymmetric fission is observed in this reaction at an excitation energy of 33.6 MeV. The results are consistent with the β-delayed fission measurements and indicate the presence of shell effects even at higher exciation energies.

  6. Nuclear fission of Fm isotopes

    SciTech Connect

    Asano, T.; Wada, T.; Ohta, M.; Chiba, S.

    2010-06-01

    Multi-modal fission has been systematically investigated for the series of isotopes of Fm and Cf. The multi-dimensional Langevin-type stochastic differential equation is used for the dynamical calculation. The primary fission mode changes from mass-asymmetric fission to mass-symmetric fission with the increase of neutron numbers for both Fm and Cf cases.

  7. Characterization of advanced thermionic energy converters for modular power units

    NASA Astrophysics Data System (ADS)

    Thayer, Kevin L.; Ramalingam, Mysore L.; Lamp, Thomas R.

    1995-01-01

    The results of the initial characterization of two advanced, heat pipe cooled planar thermionic energy converters are presented. The advanced converters utilize chemical vapor deposited (CVD) rhenium on molybdenum for both the emitter and collector electrodes. Waste heat is rejected from the collector electrode by a niobium heat pipe that contains sodium as the working fluid. Output power densities in the range from 0.7 to 10.43 watts/cm2 were recorded using sweep blasing for emitter temperatures in the range from 1573 to 1950 K. Tests were conducted to investigate the design of a power conversion circuit for a series string of converters. Static loading of the converters was performed to verify the operation of the converters in an actual application. The dynamic switching characteristics of one converter were measured to evaluate the possibility of interfacing a pulse-width modulated (PWM) power regulator directly to a thermionic source.

  8. Renewable Energy Laboratory Development for Biofuels Advanced Combustion Studies

    SciTech Connect

    Soloiu, Valentin A.

    2012-03-31

    The research advanced fundamental science and applied engineering for increasing the efficiency of internal combustion engines and meeting emissions regulations with biofuels. The project developed a laboratory with new experiments and allowed investigation of new fuels and their combustion and emissions. This project supports a sustainable domestic biofuels and automotive industry creating economic opportunities across the nation, reducing the dependence on foreign oil, and enhancing U.S. energy security. The one year period of research developed fundamental knowledge and applied technology in advanced combustion, emissions and biofuels formulation to increase vehicle's efficiency. Biofuels combustion was investigated in a Compression Ignition Direct Injection (DI) to develop idling strategies with biofuels and an Indirect Diesel Injection (IDI) intended for auxiliary power unit.

  9. Benchmark test of neutron transport calculations: indium, nickel, gold, europium, and cobalt activation with and without energy moderated fission neutrons by iron simulating the Hiroshima atomic bomb casing.

    PubMed

    Iwatani, K; Hoshi, M; Shizuma, K; Hiraoka, M; Hayakawa, N; Oka, T; Hasai, H

    1994-10-01

    A benchmark test of the Monte Carlo neutron and photon transport code system (MCNP) was performed using a bare- and energy-moderated 252Cf fission neutron source which was obtained by transmission through 10-cm-thick iron. An iron plate was used to simulate the effect of the Hiroshima atomic bomb casing. This test includes the activation of indium and nickel for fast neutrons and gold, europium, and cobalt for thermal and epithermal neutrons, which were inserted in the moderators. The latter two activations are also to validate 152Eu and 60Co activity data obtained from the atomic bomb-exposed specimens collected at Hiroshima and Nagasaki, Japan. The neutron moderators used were Lucite and Nylon 6 and the total thickness of each moderator was 60 cm or 65 cm. Measured activity data (reaction yield) of the neutron-irradiated detectors in these moderators decreased to about 1/1,000th or 1/10,000th, which corresponds to about 1,500 m ground distance from the hypocenter in Hiroshima. For all of the indium, nickel, and gold activity data, the measured and calculated values agreed within 25%, and the corresponding values for europium and cobalt were within 40%. From this study, the MCNP code was found to be accurate enough for the bare- and energy-moderated 252Cf neutron activation calculations of these elements using moderators containing hydrogen, carbon, nitrogen, and oxygen. PMID:8083048

  10. Benchmark test of neutron transport calculations: Indium, nickel, gold, europium, and cobalt activation with and without energy moderated fission neutrons by iron simulating the Hiroshima atomic bomb casing

    SciTech Connect

    Iwatani, Kazuo; Shizuma, Kiyoshi; Hasai, Hiromi; Hoshi, Masaharu; Hiraoka, Masayuki; Hayakawa, Norihiko; Oka, Takamitsu

    1994-10-01

    A benchmark test of the Monte Carlo neutron and photon transport code system (MCNP) was performed using a bare- and energy-moderated {sup 252}Cf fission neutron source which was obtained by transmission through 10-cm-thick iron. An iron plate was used to simulate the effect of the Hiroshima atomic bomb casing. This test includes the activation of indium and nickel for fast neutrons and gold, europium, and cobalt for thermal and epithermal neutrons, which were inserted in the moderators. The latter two activations are also to validate {sup 152}Eu and {sup 60}Co activity data obtained from the atomic bomb-exposed specimens collected at Hiroshima and Nagasaki, Japan. The neutron moderators used were Lucite and Nylon 6 and the total thickness of each moderator was 60 cm or 65 cm. Measured activity data (reaction yield) of the neutron-irradiated detectors in these moderators decreased to about 1/1,000th or 1/10,000th, which corresponds to about 1,500 m ground distance from the hypocenter in Hiroshima. For all of the indium, nickel, and gold activity data, the measured and calculated values agreed within 25%, and the corresponding values for europium and cobalt were within 40%. From this study, the MCNP code was found to be accurate enough for the bare- and energy-moderated {sup 252}Cf neutron activation calculations of these elements using moderators containing hydrogen, carbon, nitrogen, and oxygen. 18 refs., 10 figs., 4 tabs.

  11. Benchmark test of neutron transport calculations: indium, nickel, gold, europium, and cobalt activation with and without energy moderated fission neutrons by iron simulating the Hiroshima atomic bomb casing.

    PubMed

    Iwatani, K; Hoshi, M; Shizuma, K; Hiraoka, M; Hayakawa, N; Oka, T; Hasai, H

    1994-10-01

    A benchmark test of the Monte Carlo neutron and photon transport code system (MCNP) was performed using a bare- and energy-moderated 252Cf fission neutron source which was obtained by transmission through 10-cm-thick iron. An iron plate was used to simulate the effect of the Hiroshima atomic bomb casing. This test includes the activation of indium and nickel for fast neutrons and gold, europium, and cobalt for thermal and epithermal neutrons, which were inserted in the moderators. The latter two activations are also to validate 152Eu and 60Co activity data obtained from the atomic bomb-exposed specimens collected at Hiroshima and Nagasaki, Japan. The neutron moderators used were Lucite and Nylon 6 and the total thickness of each moderator was 60 cm or 65 cm. Measured activity data (reaction yield) of the neutron-irradiated detectors in these moderators decreased to about 1/1,000th or 1/10,000th, which corresponds to about 1,500 m ground distance from the hypocenter in Hiroshima. For all of the indium, nickel, and gold activity data, the measured and calculated values agreed within 25%, and the corresponding values for europium and cobalt were within 40%. From this study, the MCNP code was found to be accurate enough for the bare- and energy-moderated 252Cf neutron activation calculations of these elements using moderators containing hydrogen, carbon, nitrogen, and oxygen.

  12. Fission dynamics study in 243Am and 254Fm

    NASA Astrophysics Data System (ADS)

    Banerjee, K.; Ghosh, T. K.; Roy, P.; Bhattacharya, S.; Chaudhuri, A.; Bhattacharya, C.; Pandey, R.; Kundu, S.; Mukherjee, G.; Rana, T. K.; Meena, J. K.; Mohanto, G.; Dubey, R.; Saneesh, N.; Sugathan, P.; Guin, R.; Das, S.; Bhattacharya, P.

    2016-06-01

    Fission fragment mass distributions in the reactions 11B + 232Th and 11B + 243Am were measured in an energy range around the barrier. No sudden change in the width of the mass distribution as a function of center-of-mass energy was observed at near-barrier energies, indicating no quasifission transition in the near-barrier energies. Interestingly, the previous measurements of fission fragment angular anisotropies for the same systems showed significant departure from the statistical saddle-point model predictions at near-barrier energies, indicating the presence of nonequilibrium fission processes.

  13. Shape Isomers - a Key to Fission Barriers

    NASA Astrophysics Data System (ADS)

    Oberstedt, S.; Hambsch, F.-J.; Kornilov, N.; Lövestam, G.; Oberstedt, A.; Gawrys, M.

    2008-04-01

    Quantitative predictions of fission product yields are relevant for the reliable operation of different modern nuclear applications. This concerns the realistic characterizations of the radio-toxicity of the fuel elements after the envisaged extended irradiation, as well as sub-critical assemblies, where the number of delayed neutrons from minor actinides is determined by the characteristic emission yields of the corresponding so-called pre-cursor isotopes. However, to be able to make more reliable quantitative predictions of fission characteristics requires the better understanding of the fission process itself. For this purpose a better knowledge about the distinct structure of the nuclear energy landscape around the fission barrier is indispensable. In particular, the question should be answered, whether the fission barrier is either double- or triple-humped or even multi-humped as been proposed within the multi-modal neck rupture model. Despite quite some effort based on different experimental techniques and theoretical approaches, this question remains still unanswered. There is still no consistent picture of the fission barrier available and hence, different sets of barrier parameters are in use, unable to describe the different observed phenomena in a coherent way. With the systematic investigation of shape isomer population, its decay modes as well as the branching ratio, precise information can be obtained to resolve the puzzling situation. The experimental approach will be discussed and results from first experiments presented.

  14. Enhanced trigger for the NIFFTE fissionTPC in presence of high-rate alpha backgrounds

    NASA Astrophysics Data System (ADS)

    Bundgaard, Jeremy; Niffte Collaboration

    2015-10-01

    Nuclear physics and nuclear energy communities call for new, high precision measurements to improve existing fission models and design next generation reactors. The Neutron Induced Fission Fragment Tracking experiment (NIFFTE) has developed the fission Time Projection Chamber (fissionTPC) to measure neutron induced fission with unrivaled precision. The fissionTPC is annually deployed to the Weapons Neutron Research facility at Los Alamos Neutron Science Center where it operates with a neutron beam passing axially through the drift volume, irradiating heavy actinide targets to induce fission. The fissionTPC was developed at the Lawrence Livermore National Laboratory's TPC lab, where it measures spontaneous fission from radioactive sources to characterize detector response, improve performance, and evolve the design. To measure 244Cm, we've developed a fission trigger to reduce the data rate from alpha tracks while maintaining a high fission detection efficiency. In beam, alphas from 239Pu are a large background when detecting fission fragments; implementing the fission trigger will greatly reduce this background. The implementation of the cathode fission trigger in the fissionTPC will be presented along with a detailed study of its efficiency.

  15. Solution-processable singlet fission photovoltaic devices.

    PubMed

    Yang, Le; Tabachnyk, Maxim; Bayliss, Sam L; Böhm, Marcus L; Broch, Katharina; Greenham, Neil C; Friend, Richard H; Ehrler, Bruno

    2015-01-14

    We demonstrate the successful incorporation of a solution-processable singlet fission material, 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene), into photovoltaic devices. TIPS-pentacene rapidly converts high-energy singlet excitons into pairs of triplet excitons via singlet fission, potentially doubling the photocurrent from high-energy photons. Low-energy photons are captured by small-bandgap electron-accepting lead chalcogenide nanocrystals. This is the first solution-processable singlet fission system that performs with substantial efficiency with maximum power conversion efficiencies exceeding 4.8%, and external quantum efficiencies of up to 60% in the TIPS-pentacene absorption range. With PbSe nanocrystal of suitable bandgap, its internal quantum efficiency reaches 170 ± 30%.

  16. The fissionTPC

    NASA Astrophysics Data System (ADS)

    Heffner, Mike

    2014-03-01

    A new instument to study fission, called the fission TPC, has been constructed to make high accuracy measurements of neutron induced fission cross-sections of the major actinides. Most of the cross sections have been measured over the last 60 years, although improvements in the accuracy of the data appear unlikely with the current technology. A potential breakthrough is the deployment of the Time Projection Chamber (TPC) which was developed within the particle physics community. The NIFFTE collaboration, a group of 7 universities and 4 national laboratories, has undertaken the task of building the first TPC for this purpose. In this talk I will present the fission TPC design, challenges that had to be addressed, and the performance of the detector.

  17. True ternary fission

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, K. R.; Balasubramaniam, M.; von Oertzen, W.

    2015-04-01

    The study of the ternary fission of nuclei has received new interest recently. It is of general interest for nuclear dynamics, although the process is very rare. In the present work, we discuss the possibilities of true ternary fission (fragment masses A >30 ) in 252Cf for different mass splits. These mass splits are strongly favored in a collinear geometry. Based on the three cluster model (TCM), it is shown that the true ternary fission into fragments with almost equal masses is one of the possible fission modes in 252Cf . For general decays it is shown that the formation of the lightest fragment at the center has the highest probability. Further the formation of tin isotopes and/or other closed shell fragments are favored. For the decay products the presence of closed shell nuclei among the three fragments enhances the decay probabilities.

  18. Advanced Thermal Energy Storage: Novel Tuning of Critical Fluctuations for Advanced Thermal Energy Storage

    SciTech Connect

    2011-12-01

    HEATS Project: NAVITASMAX is developing a novel thermal energy storage solution. This innovative technology is based on simple and complex supercritical fluids— substances where distinct liquid and gas phases do not exist, and tuning the properties of these fluid systems to increase their ability to store more heat. In solar thermal storage systems, heat can be stored in NAVITASMAX’s system during the day and released at night—when the sun is not shining—to drive a turbine and produce electricity. In nuclear storage systems, heat can be stored in NAVITASMAX’s system at night and released to produce electricity during daytime peak-demand hours.

  19. Vector soliton fission.

    PubMed

    Lu, F; Lin, Q; Knox, W H; Agrawal, Govind P

    2004-10-29

    We investigate the vectorial nature of soliton fission in an isotropic nonlinear medium both theoretically and experimentally. As a specific example, we show that supercontinuum generation in a tapered fiber is extremely sensitive to the input state of polarization. Multiple vector solitons generated through soliton fission exhibit different states of elliptical polarization while emitting nonsolitonic radiation with complicated polarization features. Experiments performed with a tapered fiber agree with our theoretical description.

  20. Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance; Grocery Stores (Revised) (Book)

    SciTech Connect

    Hendron, B.

    2013-07-01

    The U.S. Department of Energy developed the Advanced Energy Retrofit Guides (AERGs) to provide specific methodologies, information, and guidance to help energy managers and other stakeholders successfully plan and execute energy efficiency improvements. Detailed technical discussion is fairly limited in these guides. Instead, we emphasize actionable information, practical methodologies, diverse case studies, and unbiased evaluations of the most promising retrofit measures for each building type. A series of AERGs is under development, addressing key segments of the commercial building stock. Grocery stores were selected as one of the highest priority sectors, because they represent one of the most energy-intensive market segments.

  1. Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance, K-12 Schools (Book)

    SciTech Connect

    Not Available

    2013-02-01

    The U.S. Department of Energy developed the K-12 Advanced Energy Retrofit Guide to provide specific methodologies, information, and guidance to help energy managers and other stakeholders plan and execute energy efficiency improvements. We emphasize actionable information, practical methodologies, diverse case studies, and unbiased evaluation of the most promising retrofit measure for each building type. K-12 schools were selected as one of the highest priority building sectors, because schools affect the lives of most Americans. They also represent approximately 8% of the energy use and 10% of the floor area in commercial buildings.

  2. Fission neutron spectra measurements at LANSCE - status and plans

    SciTech Connect

    Haight, Robert C; Noda, Shusaku; Nelson, Ronald O; O' Donnell, John M; Devlin, Matt; Chatillon, Audrey; Granier, Thierry; Taieb, Julien; Laurent, Benoit; Belier, Gilbert; Becker, John A; Wu, Ching - Yen

    2009-01-01

    A program to measure fission neutron spectra from neutron-induced fission of actinides is underway at the Los Alamos Neutron Science Center (LANSCE) in a collaboration among the CEA laboratory at Bruyeres-le-Chatel, Lawrence Livermore National Laboratory and Los Alamos National Laboratory. The spallation source of fast neutrons at LANSCE is used to provide incident neutron energies from less than 1 MeV to 100 MeV or higher. The fission events take place in a gas-ionization fission chamber, and the time of flight from the neutron source to that chamber gives the energy of the incident neutron. Outgoing neutrons are detected by an array of organic liquid scintillator neutron detectors, and their energies are deduced from the time of flight from the fission chamber to the neutron detector. Measurements have been made of the fission neutrons from fission of {sup 235}U, {sup 238}U, {sup 237}Np and {sup 239}Pu. The range of outgoing energies measured so far is from 1 MeV to approximately 8 MeV. These partial spectra and average fission neutron energies are compared with evaluated data and with models of fission neutron emission. Results to date will be presented and a discussion of uncertainties will be given in this presentation. Future plans are to make significant improvements in the fission chambers, neutron detectors, signal processing, data acquisition and the experimental environment to provide high fidelity data including mea urements of fission neutrons below 1 MeV and improvements in the data above 8 MeV.

  3. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on 239Pu, 235U, 238U

    NASA Astrophysics Data System (ADS)

    Selby, H. D.; Mac Innes, M. R.; Barr, D. W.; Keksis, A. L.; Meade, R. A.; Burns, C. J.; Chadwick, M. B.; Wallstrom, T. C.

    2010-12-01

    We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for 99Mo, 95Zr, 137Cs, 140Ba, 141,143Ce, and 147Nd. Modest incident-energy dependence exists for the 147Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by ˜5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except for 99Mo

  4. Electron-capture delayed fission properties of 244Es

    SciTech Connect

    Shaughnessy, Dawn A.; Gregorich, Kenneth E.; Adams, Jeb L.; Lane, Michael R.; Laue, Carola A.; Lee, Diana M.; McGrath, Christopher A.; Ninov, Victor; Patin, Joshua B.; Strellis, Dan A.; Sylwester, Eric R.; Wilk, Philip A.; Hoffman, Darleane C.

    2001-03-16

    Electron-capture delayed fission was observed in {sup 244}Es produced via the {sup 237}Np({sup 12}C,5n){sup 244}Es reaction at 81 MeV (on target) with a production cross section of 0.31{+-}0.12 {micro}b. The mass-yield distribution of the fission fragments is highly asymmetric. The average preneutron-emission total kinetic energy of the fragments was measured to be 186{+-}19 MeV. Based on the ratio of the number of fission events to the measured number of {alpha} decays from the electron-capture daughter {sup 244}Cf (100% {alpha} branch), the probability of delayed fission was determined to be (1.2{+-}0.4) x 10{sup -4}. This value for the delayed fission probability fits the experimentally observed trend of increasing delayed fission probability with increasing Q value for electron-capture.

  5. Possible origin of transition from symmetric to asymmetric fission

    NASA Astrophysics Data System (ADS)

    Paşca, H.; Andreev, A. V.; Adamian, G. G.; Antonenko, N. V.

    2016-09-01

    The charged distributions of fragments produced in the electromagnetic-induced fission of the even-even isotopes of Rn, Ra, Th, and U are described within an improved scission-point model and compared with the available experimental data. The three-equal-peaked charge distributions are predicted for several fissioning nuclei with neutron number N = 136. The possible explanation of the transition from a symmetric fission mode to an asymmetric one around N ∼ 136 is presented. The excitation energy dependencies of the asymmetric and symmetric fission modes are anticipated.

  6. NEET Micro-Pocket Fission Detector. Final Project report

    SciTech Connect

    Unruh, T.; Rempe, Joy; McGregor, Douglas; Ugorowski, Philip; Reichenberger, Michael; Ito, Takashi; Villard, J.-F.

    2014-09-01

    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 funded by 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

  7. In-beam Fission Study at JAEA

    NASA Astrophysics Data System (ADS)

    Nishio, Katsuhisa

    2013-12-01

    Fission fragment mass distributions were measured in heavy-ion induced fissions using 238U target nucleus. The measured mass distributions changed drastically with incident energy. The results are explained by a change of the ratio between fusion and quasifission with nuclear orientation. A calculation based on a fluctuation dissipation model reproduced the mass distributions and their incident energy dependence. Fusion probability was determined in the analysis. Evaporation residue cross sections were calculated with a statistical model in the reactions of 30Si + 238U and 34S + 238U using the obtained fusion probability in the entrance channel. The results agree with the measured cross sections for seaborgium and hassium isotopes.

  8. The quantum and thermodynamical characteristics of fission taking into account adiabatic and nonadiabatic modes of motion

    SciTech Connect

    Kadmensky, S. G.

    2007-09-15

    In the framework of the quantum theory of spontaneous and low-energy induced fission, the nature of quantum and thermodynamical properties of a fissioning system is analyzed taking into account adiabatic and nonadiabatic modes of motion for different fission stages. It is shown that, owing to the influence of the Coriolis interaction, the states of the fissile nucleus and of primary fission products are cold and strongly nonequilibrium. The important role of superfluid and pairing nucleon-nucleon correlations for binary and ternary fission is demonstrated. The mechanism of pumping of high values of relative orbital momenta and spins of fission fragments for binary and ternary fission and the nonevaporation mechanism of formation of third particles for ternary fission are investigated. The anisotropies and P-odd, P-even, and T-odd asymmetries for angular distributions of fission products are analyzed.

  9. Scientific and technological advancements in inertial fusion energy

    DOE PAGES

    Hinkel, D. E.

    2013-09-26

    Scientific advancements in inertial fusion energy (IFE) were reported on at the IAEA Fusion Energy Conference, October 2012. Results presented transect the different ways to assemble the fuel, different scenarios for igniting the fuel, and progress in IFE technologies. The achievements of the National Ignition Campaign within the USA, using the National Ignition Facility (NIF) to indirectly drive laser fusion, have found beneficial the achievements in other IFE arenas such as directly driven laser fusion and target fabrication. Moreover, the successes at NIF have pay-off to alternative scenarios such as fast ignition, shock ignition, and heavy-ion fusion as well asmore » to directly driven laser fusion. As a result, this synergy is summarized here, and future scientific studies are detailed.« less

  10. Scientific and technological advancements in inertial fusion energy

    SciTech Connect

    Hinkel, D. E.

    2013-09-26

    Scientific advancements in inertial fusion energy (IFE) were reported on at the IAEA Fusion Energy Conference, October 2012. Results presented transect the different ways to assemble the fuel, different scenarios for igniting the fuel, and progress in IFE technologies. The achievements of the National Ignition Campaign within the USA, using the National Ignition Facility (NIF) to indirectly drive laser fusion, have found beneficial the achievements in other IFE arenas such as directly driven laser fusion and target fabrication. Moreover, the successes at NIF have pay-off to alternative scenarios such as fast ignition, shock ignition, and heavy-ion fusion as well as to directly driven laser fusion. As a result, this synergy is summarized here, and future scientific studies are detailed.

  11. Bimodal symmetric fission observed in the heaviest elements

    SciTech Connect

    Hulet, E.K.; Wild, J.F.; Dougan, R.J.; Lougheed, R.W.; Landrum, J.H.; Dougan, A.D.; Schadel, M.; Hahn, R.L.; Baisden, P.A.; Henderson, C.M.

    1986-01-27

    We measured the mass and kinetic-energy partitioning in the spontaneous fission of /sup 258/Fm, /sup 259/Md, /sup 260/Md, /sup 258/No, and /sup 260/(104). All fissioned with mass distributions that were symmetric. Total-kinetic-energy distributions peaked near either 200 or 235 MeV. Surprisingly, these energy distributions were skewed upward or downward from the peak in each case, except for /sup 260/(104), indicating a composite of two energy distributions. We interpret this as a mixture of liquid-drop-like and fragment-shell directed symmetric fission, although theory had not anticipated this phenomenon.

  12. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    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 in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  13. Radiation Effects in Fission and Fusion Reactors

    NASA Astrophysics Data System (ADS)

    Odette, G. Robert; Wirth, Brian D.

    Since the prediction of "Wigner disease" [1] and the subsequent observation of anisotropic growth of the graphite used in the Chicago Pile, the effects of radiation on materials has been an important technological concern. The broad field of radiation effects impacts many critical advanced technologies, ranging from semiconductor processing to severe materials degradation in nuclear reactor environments. Radiation effects also occur in many natural environments, ranging from deep space to inside the Earth's crust. As selected examples that involve many basic phenomena that cross-cut and illustrate the broader impacts of radiation exposure on materials, this article focuses on modeling microstructural changes in iron-based ferritic alloys under high-energy neutron irradiation relevant to light water fission reactor pressure vessels. We also touch briefly on radiation effects in structural alloys for fusion reactor first wall and blanket structures; in this case the focus is on modeling the evolution of self-interstitial atom clusters and dislocation loops. Note, since even the narrower topic of structural materials for nuclear energy applications encompass a vast literature dating from 1942, the references included in this article are primarily limited to these two narrower subjects. Thus, the references cited here are presented as examples, rather than comprehensive bibliographies. However, the interested reader is referred to proceedings of continuing symposia series that have been sponsored by several organizations, several monographs [2-4] and key journals (e.g., Journal of Nuclear Materials, Radiation Effects and Defects in Solids).

  14. Energy and economic trade offs for advanced technology subsonic aircraft

    NASA Technical Reports Server (NTRS)

    Maddalon, D. V.; Wagner, R. D.

    1976-01-01

    Changes in future aircraft technology which conserve energy are studied, along with the effect of these changes on economic performance. Among the new technologies considered are laminar-flow control, composite materials with and without laminar-flow control, and advanced airfoils. Aircraft design features studied include high-aspect-ratio wings, thickness ratio, and range. Engine technology is held constant at the JT9D level. It is concluded that wing aspect ratios of future aircraft are likely to significantly increase as a result of new technology and the push of higher fuel prices. Whereas current airplanes have been designed for AR = 7, supercritical technology and much higher fuel prices will drive aspect ratio to the AR = 9-10 range. Composite materials may raise aspect ratio to about 11-12 and practical laminar flow-control systems may further increase aspect ratio to 14 or more. Advanced technology provides significant reductions in aircraft take-off gross weight, energy consumption, and direct operating cost.

  15. Angular momentum effects in multimodal fission of {sup 226}Th

    SciTech Connect

    Chubarian, G.G.; Hurst, B.J.; OKelly, D.; Schmitt, R.P.; Itkis, M.G.; Kondratiev, N.A.; Kozulin, E.M.; Oganessian, Y.T.; Pashkevich, V.V.; Pokrovsky, I.V.; Salamatin, V.S.; Rusanov, A.Y.; Calabretta, L.; Maiolino, C.; Lukashin, K.; Agodi, C.; Bellia, G.; Hanappe, F.; Liatard, E.; Huck, A.; Stuttge, L.

    1998-12-01

    The {gamma}-rays from the multimodal fission of the {sup 226}Th formed in {sup 18}O+{sup 208}Pb was investigated at the near- and sub-barrier energies. The corresponding excitation energies at the saddle point, E{sub sp}{sup {asterisk}}, ranged from 23 to 26 MeV. The average {gamma}-ray multiplicities and relative {gamma}-ray energies as a function of the mass of the fission fragments exhibits a complex structure and strong variations. Such strong variations have never been previously observed in heavy ion-induced fusion-fission reactions. Obtained results may be explained with the influence of shell effects on the properties of the fission fragments. Present work is the one in series of investigation of the multimodal fission phenomena in At-Th region. {copyright} {ital 1998 American Institute of Physics.}

  16. Applications of Event-by-Event Fission Modeling with FREYA

    SciTech Connect

    Vogt, R; Randrup, J

    2011-09-16

    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. We first discuss the present status of FREYA, which has now been extended to include spontaneous fission. Concentrating on {sup 239}Pu(n{sub th},f), {sup 240}Pu(sf) and {sup 252}Cf(sf), 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 suggest novel fission observables that could be measured with modern detectors.

  17. Advanced Technology Paths to Global Climate Stability: Energy for a Greenhouse Planet

    NASA Astrophysics Data System (ADS)

    Hoffert, Martin I.; Caldeira, Ken; Benford, Gregory; Criswell, David R.; Green, Christopher; Herzog, Howard; Jain, Atul K.; Kheshgi, Haroon S.; Lackner, Klaus S.; Lewis, John S.; Lightfoot, H. Douglas; Manheimer, Wallace; Mankins, John C.; Mauel, Michael E.; Perkins, L. John; Schlesinger, Michael E.; Volk, Tyler; Wigley, Tom M. L.

    2002-11-01

    Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (~1013 watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.

  18. Advanced technology paths to global climate stability: energy for a greenhouse planet.

    PubMed

    Hoffert, Martin I; Caldeira, Ken; Benford, Gregory; Criswell, David R; Green, Christopher; Herzog, Howard; Jain, Atul K; Kheshgi, Haroon S; Lackner, Klaus S; Lewis, John S; Lightfoot, H Douglas; Manheimer, Wallace; Mankins, John C; Mauel, Michael E; Perkins, L John; Schlesinger, Michael E; Volk, Tyler; Wigley, Tom M L

    2002-11-01

    Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (approximately 10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development. PMID:12411695

  19. Advanced technology paths to global climate stability: energy for a greenhouse planet.

    PubMed

    Hoffert, Martin I; Caldeira, Ken; Benford, Gregory; Criswell, David R; Green, Christopher; Herzog, Howard; Jain, Atul K; Kheshgi, Haroon S; Lackner, Klaus S; Lewis, John S; Lightfoot, H Douglas; Manheimer, Wallace; Mankins, John C; Mauel, Michael E; Perkins, L John; Schlesinger, Michael E; Volk, Tyler; Wigley, Tom M L

    2002-11-01

    Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (approximately 10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.

  20. On the fission of the heaviest fermium isotopes

    SciTech Connect

    C-acute-accentwiok, S.; Rozmej, P.; Sobiczewski, A.

    1987-12-10

    Potential energy of /sup 258/Fm is calculated in multidimensional deformation spaceias a function of both (reflection-) symmetric and asymmetric shapes. The inclusion of the asymmetric shapes is found important as it ''opens a pass'' between the two fission valleys: one corresponding to compact and the other to elongated shapes of the nucleus. Thus, it makes both valleys accessible to the fissioning nucleus.

  1. Advanced model for fast assessment of piezoelectric micro energy harvesters

    NASA Astrophysics Data System (ADS)

    Ardito, Raffaele; Corigliano, Alberto; Gafforelli, Giacomo; Valzasina, Carlo; Procopio, Francesco; Zafalon, Roberto

    2016-04-01

    The purpose of this work is to present recent advances in modelling and design of piezoelectric energy harvesters, in the framework of Micro-Electro-Mechanical Systems (MEMS). More specifically, the case of inertial energy harvesting is considered, in the sense that the kinetic energy due to environmental vibration is transformed into electrical energy by means of piezoelectric transduction. The execution of numerical analyses is greatly important in order to predict the actual behaviour of MEMS devices and to carry out the optimization process. In the common practice, the results are obtained by means of burdensome 3D Finite Element Analyses (FEA). The case of beams could be treated by applying 1D models, which can enormously reduce the computational burden with obvious benefits in the case of repeated analyses. Unfortunately, the presence of piezoelectric coupling may entail some serious issues in view of its intrinsically three-dimensional behaviour. In this paper, a refined, yet simple, model is proposed with the objective of retaining the Euler-Bernoulli beam model, with the inclusion of effects connected to the actual three-dimensional shape of the device. The proposed model is adopted to evaluate the performances of realistic harvesters, both in the case of harmonic excitation and for impulsive loads.

  2. Torin1-mediated TOR kinase inhibition reduces Wee1 levels and advances mitotic commitment in fission yeast and HeLa cells.

    PubMed

    Atkin, Jane; Halova, Lenka; Ferguson, Jennifer; Hitchin, James R; Lichawska-Cieslar, Agata; Jordan, Allan M; Pines, Jonathon; Wellbrock, Claudia; Petersen, Janni

    2014-03-15

    The target of rapamycin (TOR) kinase regulates cell growth and division. Rapamycin only inhibits a subset of TOR activities. Here we show that in contrast to the mild impact of rapamycin on cell division, blocking the catalytic site of TOR with the Torin1 inhibitor completely arrests growth without cell death in Schizosaccharomyces pombe. A mutation of the Tor2 glycine residue (G2040D) that lies adjacent to the key Torin-interacting tryptophan provides Torin1 resistance, confirming the specificity of Torin1 for TOR. Using this mutation, we show that Torin1 advanced mitotic onset before inducing growth arrest. In contrast to TOR inhibition with rapamycin, regulation by either Wee1 or Cdc25 was sufficient for this Torin1-induced advanced mitosis. Torin1 promoted a Polo and Cdr2 kinase-controlled drop in Wee1 levels. Experiments in human cell lines recapitulated these yeast observations: mammalian TOR (mTOR) was inhibited by Torin1, Wee1 levels declined and mitotic commitment was advanced in HeLa cells. Thus, the regulation of the mitotic inhibitor Wee1 by TOR signalling is a conserved mechanism that helps to couple cell cycle and growth controls.

  3. Rechargeable dual-metal-ion batteries for advanced energy storage.

    PubMed

    Yao, Hu-Rong; You, Ya; Yin, Ya-Xia; Wan, Li-Jun; Guo, Yu-Guo

    2016-04-14

    Energy storage devices are more important today than any time before in human history due to the increasing demand for clean and sustainable energy. Rechargeable batteries are emerging as the most efficient energy storage technology for a wide range of portable devices, grids and electronic vehicles. Future generations of batteries are required to have high gravimetric and volumetric energy, high power density, low price, long cycle life, high safety and low self-discharge properties. However, it is quite challenging to achieve the above properties simultaneously in state-of-the-art single metal ion batteries (e.g. Li-ion batteries, Na-ion batteries and Mg-ion batteries). In this contribution, hybrid-ion batteries in which various metal ions simultaneously engage to store energy are shown to provide a new perspective towards advanced energy storage: by connecting the respective advantages of different metal ion batteries they have recently attracted widespread attention due to their novel performances. The properties of hybrid-ion batteries are not simply the superposition of the performances of single ion batteries. To enable a distinct description, we only focus on dual-metal-ion batteries in this article, for which the design and the benefits are briefly discussed. We enumerate some new results about dual-metal-ion batteries and demonstrate the mechanism for improving performance based on knowledge from the literature and experiments. Although the search for hybrid-ion batteries is still at an early age, we believe that this strategy would be an excellent choice for breaking the inherent disadvantages of single ion batteries in the near future.

  4. Fossil energy: From laboratory to marketplace. Part 2, The role of advanced research

    SciTech Connect

    Not Available

    1992-03-01

    The purpose of this work is to provide a summary description of the role of advanced research in the overall Fossil Energy R&D program successes. It presents the specific Fossil Energy advanced research products that have been adopted commercially or fed into other R&D programs as part of the crosscutting enabling technology base upon which advanced systems are based.

  5. Comparison of fission modes in {sup 252}Cf, {sup 257}Fm, and {sup 260}Md

    SciTech Connect

    Aarle, J. van; Siemon, K.; Patzelt, P.; Wild, J. F.; Lougheed, R. W.; Westmeier, W.

    1998-10-26

    Although the spontaneous-fission properties of heavy actinides have been studied for well over 35 years, many interesting and informative details continue to come into light. During the last decade, the spontaneous fission of {sup 252}Cf, {sup 257}Fm and {sup 260}Md has been extensively investigated at the Philipps University of Marburg, by means of a gadolinium-doped liquid scintillation tank for neutron counting and surface barrier detectors for fission fragment detection. The three nuclides represent the transition from the well-known asymmetric fission yield distribution, as it is characteristic for {sup 252}Cf, to a much more symmetrical one, found in the fission of {sup 260}Md. Therefore, trends in the dynamical changes of fission properties have been derived from these studies. For the spontaneous fission of {sup 252}Cf and {sup 260}Md, it was already shown that different fission modes, as proposed by theoretical calculations of Brosa et al. (5), could be separated, using the correlation between the neutrons emitted in a fission event and both the observed fission-fragment mass and the total kinetic energy (1, 2). In the case of {sup 257}Fm, no theoretical calculations for fission modes exist. However, from the fission properties of the two surrounding actinides, one can expect at least three different fission modes, namely two 'standard' and the 'supershort' mode. In this paper, results from the recent {sup 257}Fm experiment will be presented and compared to systematics extracted from the fission properties of other heavy actinides.

  6. Aggregate Fission-Product Decay Data Based on ENDF/B-IV and -V.

    1982-10-12

    Version 02 The ENDF/B-IV fission-product files contain neutron cross sections, decay constants, decay energies, and other decay data for 824 important fission products. They also contain fission yields for these fission products produced by one or more fission-neutron energies (14 MeV, fast, and thermal fission). Also, spectral data exist for the most important decay-heat contributors among the 824 nuclides. Because the spectra are based on fission pulses, the libraries have a general utility. The exponentialmore » fits, for example, can be folded into any power (fission) history that can be described analytically or by a histogram representation. The effects of neutron absorption are also treated and approximately accounted for in the methodology.« less

  7. Technical Considerations for Advanced Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Houts, Michael G.

    1999-01-01

    This presentation reviews concerns involving advanced propulsion systems. The problems involved with the use of Am-242m, is that it has a high "eta" plus an order of magnitude larger fission cross section than other fissionable materials, and that it is extremely rare. However other americium isotopes are much more common, but extremely effective isotopic separation is required. Deuterium-Tritium fusion is also not attractive for space propulsion applications. Because the pulsed systems cannot breed adequate amounts of tritium and it is difficult and expensive to bring tritium from Earth. The systems that do breed tritium have severely limited performance. However, other fusion processes should still be evaluated. Another problem with advanced propellants is that inefficiencies in converting the total energy generated into propellant energy can lead to tremendous heat rejection requirements. Therefore Many. advanced propulsion concepts benefit greatly from low-mass radiators.

  8. Quasifission and fusion-fission in reactions with massive nuclei: Comparison of reactions leading to the Z=120 element

    SciTech Connect

    Nasirov, A. K.; Giardina, G.; Mandaglio, G.; Manganaro, M.; Hanappe, F.; Heinz, S.; Hofmann, S.; Muminov, A. I.; Scheid, W.

    2009-02-15

    The yields of evaporation residues, fusion-fission, and quasifission fragments in the {sup 48}Ca+{sup 144,154}Sm and {sup 16}O+{sup 186}W reactions are analyzed in the framework of the combined theoretical method based on the dinuclear system concept and advanced statistical model. The measured yields of evaporation residues for the {sup 48}Ca+{sup 154}Sm reaction can be well reproduced. The measured yields of fission fragments are decomposed into contributions coming from fusion-fission, quasifission, and fast-fission. The decrease in the measured yield of quasifission fragments in {sup 48}Ca+{sup 154}Sm at the large collision energies and the lack of quasifission fragments in the {sup 48}Ca+{sup 144}Sm reaction are explained by the overlap in mass angle distributions of the quasifission and fusion-fission fragments. The investigation of the optimal conditions for the synthesis of the new element Z=120 (A=302) show that the {sup 54}Cr+{sup 248}Cm reaction is preferable in comparison with the {sup 58}Fe+{sup 244}Pu and {sup 64}Ni+{sup 238}U reactions because the excitation function of the evaporation residues of the former reaction is some orders of magnitude larger than that for the last two reactions.

  9. FASTGRASS implementation in BISON and Fission gas behavior characterization in UO2 and connection to validating MARMOT

    SciTech Connect

    Yun, Di; Mo, Kun; Ye, Bei; Jamison, Laura M.; Miao, Yinbin; Lian, Jie; Yao, Tiankei

    2015-09-30

    This activity is supported by the US Nuclear Energy Advanced Modeling and Simulation (NEAMS) Fuels Product Line (FPL). Two major accomplishments in FY 15 are summarized in this report: (1) implementation of the FASTGRASS module in the BISON code; and (2) a Xe implantation experiment for large-grained UO2. Both BISON AND MARMOT codes have been developed by Idaho National Laboratory (INL) to enable next generation fuel performance modeling capability as part of the NEAMS Program FPL. To contribute to the development of the Moose-Bison-Marmot (MBM) code suite, we have implemented the FASTGRASS fission gas model as a module in the BISON code. Based on rate theory formulations, the coupled FASTGRASS module in BISON is capable of modeling LWR oxide fuel fission gas behavior and fission gas release. In addition, we conducted a Xe implantation experiment at the Argonne Tandem Linac Accelerator System (ATLAS) in order to produce the needed UO2 samples with desired bubble morphology. With these samples, further experiments to study the fission gas diffusivity are planned to provide validation data for the Fission Gas Release Model in MARMOT codes.

  10. The nature of singlet exciton fission in carotenoid aggregates.

    PubMed

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

    2015-04-22

    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 of the solar spectrum to capture the energy generally lost as waste heat. However, many questions remain about the underlying fission mechanism. The relation between intermolecular geometry and singlet fission rate and yield is poorly understood and remains one of the most significant barriers to the design of new singlet fission sensitizers. Here we explore the structure-property relationship and examine the mechanism of singlet fission in aggregates of astaxanthin, a small polyene. We isolate five distinct supramolecular structures of astaxanthin generated through self-assembly in solution. Each is capable of undergoing intermolecular singlet fission, with rates of triplet generation and annihilation that can be correlated with intermolecular coupling strength. In contrast with the conventional model of singlet fission in linear molecules, we demonstrate that no intermediate states are involved in the triplet formation: instead, singlet fission occurs directly from the initial 1B(u) photoexcited state on ultrafast time scales. This result demands a re-evaluation of current theories of polyene photophysics and highlights the robustness of carotenoid singlet fission. PMID:25825939

  11. Wireless Sensor Network for Advanced Energy Management Solutions

    SciTech Connect

    Peter J. Theisen; Bin Lu, Charles J. Luebke

    2009-09-23

    Eaton has developed an advanced energy management solution that has been deployed to several Industries of the Future (IoF) sites. This demonstrated energy savings and reduced unscheduled downtime through an improved means for performing predictive diagnostics and energy efficiency estimation. Eaton has developed a suite of online, continuous, and inferential algorithms that utilize motor current signature analysis (MCSA) and motor power signature analysis (MPSA) techniques to detect and predict the health condition and energy usage condition of motors and their connect loads. Eaton has also developed a hardware and software platform that provided a means to develop and test these advanced algorithms in the field. Results from lab validation and field trials have demonstrated that the developed advanced algorithms are able to detect motor and load inefficiency and performance degradation. Eaton investigated the performance of Wireless Sensor Networks (WSN) within various industrial facilities to understand concerns about topology and environmental conditions that have precluded broad adoption by the industry to date. A Wireless Link Assessment System (WLAS), was used to validate wireless performance under a variety of conditions. Results demonstrated that wireless networks can provide adequate performance in most facilities when properly specified and deployed. Customers from various IoF expressed interest in applying wireless more broadly for selected applications, but continue to prefer utilizing existing, wired field bus networks for most sensor based applications that will tie into their existing Computerized Motor Maintenance Systems (CMMS). As a result, wireless technology was de-emphasized within the project, and a greater focus placed on energy efficiency/predictive diagnostics. Commercially available wireless networks were only utilized in field test sites to facilitate collection of motor wellness information, and no wireless sensor network products were

  12. Singlet Fission of Non-polycyclic Aromatic Molecules in Organic Photovoltaics.

    PubMed

    Kawata, So; Pu, Yong-Jin; Saito, Ayaka; Kurashige, Yuki; Beppu, Teruo; Katagiri, Hiroshi; Hada, Masaki; Kido, Junji

    2016-02-24

    Singlet fission of thienoquinoid compounds in organic photovoltaics is demonstrated. The escalation of the thienoquinoid length of the compounds realizes a suitable packing structure and energy levels for singlet fission. The magnetic-field dependence of the photocurrent and the external quantum efficiency of the devices reveal singlet fission of the compounds and dissociation of triplet excitons into charges.

  13. The Consortium for Advancing Renewable Energy Technology (CARET)

    NASA Technical Reports Server (NTRS)

    Gordon, E. M.; Henderson, D. O.; Buffinger, D. R.; Fuller, C. W.; Uribe, R. M.

    1998-01-01

    The Consortium for Advancing Renewable Energy (CARET) is a research and education program which uses the theme of renewable energy to build a minority scientist pipeline. CARET is also a consortium of four universities and NASA Lewis Research Center working together to promote science education and research to minority students using the theme of renewable energy. The consortium membership includes the HBCUs (Historically Black Colleges and Universities), Fisk, Wilberforce and Central State Universities as well as Kent State University and NASA Lewis Research Center. The various stages of this pipeline provide participating students experiences with a different emphasis. Some emphasize building enthusiasm for the classroom study of science and technology while others emphasize the nature of research in these disciplines. Still others focus on relating a practical application to science and technology. And, of great importance to the success of the program are the interfaces between the various stages. Successfully managing these transitions is a requirement for producing trained scientists, engineers and technologists. Presentations describing the CARET program have been given at this year's HBCU Research Conference at the Ohio Aerospace Institute and as a seminar in the Solar Circle Seminar series of the Photovoltaic and Space Environments Branch at NASA Lewis Research Center. In this report, we will describe the many positive achievements toward the fulfillment of the goals and outcomes of our program. We will begin with a description of the interactions among the consortium members and end with a description of the activities of each of the member institutions .

  14. Sol-gel Technology and Advanced Electrochemical Energy Storage Materials

    NASA Technical Reports Server (NTRS)

    Chu, Chung-tse; Zheng, Haixing

    1996-01-01

    Advanced materials play an important role in the development of electrochemical energy devices such as batteries, fuel cells, and electrochemical capacitors. The sol-gel process is a versatile solution for use in the fabrication of ceramic materials with tailored stoichiometry, microstructure, and properties. This processing technique is particularly useful in producing porous materials with high surface area and low density, two of the most desirable characteristics for electrode materials. In addition,the porous surface of gels can be modified chemically to create tailored surface properties, and inorganic/organic micro-composites can be prepared for improved material performance device fabrication. Applications of several sol-gel derived electrode materials in different energy storage devices are illustrated in this paper. V2O5 gels are shown to be a promising cathode material for solid state lithium batteries. Carbon aerogels, amorphous RuO2 gels and sol-gel derived hafnium compounds have been studied as electrode materials for high energy density and high power density electrochemical capacitors.

  15. Advanced Range Safety System for High Energy Vehicles

    NASA Technical Reports Server (NTRS)

    Claxton, Jeffrey S.; Linton, Donald F.

    2002-01-01

    The advanced range safety system project is a collaboration between the National Aeronautics and Space Administration and the United States Air Force to develop systems that would reduce costs and schedule for safety approval for new classes of unmanned high-energy vehicles. The mission-planning feature for this system would yield flight profiles that satisfy the mission requirements for the user while providing an increased quality of risk assessment, enhancing public safety. By improving the speed and accuracy of predicting risks to the public, mission planners would be able to expand flight envelopes significantly. Once in place, this system is expected to offer the flexibility of handling real-time risk management for the high-energy capabilities of hypersonic vehicles including autonomous return-from-orbit vehicles and extended flight profiles over land. Users of this system would include mission planners of Space Launch Initiative vehicles, space planes, and other high-energy vehicles. The real-time features of the system could make extended flight of a malfunctioning vehicle possible, in lieu of an immediate terminate decision. With this improved capability, the user would have more time for anomaly resolution and potential recovery of a malfunctioning vehicle.

  16. Advanced, High Power, Next Scale, Wave Energy Conversion Device

    SciTech Connect

    Mekhiche, Mike; Dufera, Hiz; Montagna, Deb

    2012-10-29

    The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

  17. Burning plasma regime for Fussion-Fission Research Facility

    NASA Astrophysics Data System (ADS)

    Zakharov, Leonid E.

    2010-11-01

    The basic aspects of burning plasma regimes of Fusion-Fission Research Facility (FFRF, R/a=4/1 m/m, Ipl=5 MA, Btor=4-6 T, P^DT=50-100 MW, P^fission=80-4000 MW, 1 m thick blanket), which is suggested as the next step device for Chinese fusion program, are presented. The mission of FFRF is to advance magnetic fusion to the level of a stationary neutron source and to create a technical, scientific, and technology basis for the utilization of high-energy fusion neutrons for the needs of nuclear energy and technology. FFRF will rely as much as possible on ITER design. Thus, the magnetic system, especially TFC, will take advantage of ITER experience. TFC will use the same superconductor as ITER. The plasma regimes will represent an extension of the stationary plasma regimes on HT-7 and EAST tokamaks at ASIPP. Both inductive discharges and stationary non-inductive Lower Hybrid Current Drive (LHCD) will be possible. FFRF strongly relies on new, Lithium Wall Fusion (LiWF) plasma regimes, the development of which will be done on NSTX, HT-7, EAST in parallel with the design work. This regime will eliminate a number of uncertainties, still remaining unresolved in the ITER project. Well controlled, hours long inductive current drive operation at P^DT=50-100 MW is predicted.

  18. Discovery of a new mode of nuclear fission

    SciTech Connect

    Hulet, E.K.; Wild, J.F.; Dougan, R.J.; Lougheed, R.W.; Landrum, J.H.; Dougan, A.D.; Schaedel, M.; Hahn, R.L.; Baisden, P.A.; Henderson, C.M.

    1986-01-01

    We measured the mass and kinetic-energy partitioning in the spontaneous fission of /sup 258/Fm, /sup 259/Md, /sup 260/Md, /sup 258/No, and /sup 260/(104). Surprisingly, these energy distributions were skewed upward or downward from the peak in each case, except for /sup 260/(104), indicating a composite of two energy distributions. We interpret this as a new mode of fission in which there is mixture of liquid-drop-like and fragment-shell-directed symmetric fission.

  19. Advanced Redox Flow Batteries for Stationary Electrical Energy Storage

    SciTech Connect

    Li, Liyu; Kim, Soowhan; Xia, Guanguang; Wang, Wei; Yang, Zhenguo

    2012-03-19

    This report describes the status of the advanced redox flow battery research being performed at Pacific Northwest National Laboratories for the U.S. Department of Energy’s Energy Storage Systems Program. The Quarter 1 of FY2012 Milestone was completed on time. The milestone entails completion of evaluation and optimization of single cell components for the two advanced redox flow battery electrolyte chemistries recently developed at the lab, the all vanadium (V) mixed acid and V-Fe mixed acid solutions. All the single cell components to be used in future kW-scale stacks have been identified and optimized in this quarter, which include solution electrolyte, membrane or separator; carbon felt electrode and bi-polar plate. Varied electrochemical, chemical and physical evaluations were carried out to assist the component screening and optimization. The mechanisms of the battery capacity fading behavior for the all vanadium redox flow and the Fe/V battery were discovered, which allowed us to optimize the related cell operation parameters and continuously operate the system for more than three months without any capacity decay.

  20. Nanoscience and Nanotechnology: From Energy Applications to Advanced Medical Therapies

    ScienceCinema

    Tijana Rajh

    2016-07-12

    Dr. Rajh will present a general talk on nanotechnology – an overview of why nanotechnology is important and how it is useful in various fields. The specific focus will be on Solar energy conversion, environmental applications and advanced medical therapies. She has broad expertise in synthesis and characterization of nanomaterials that are used in nanotechnology including novel hybrid systems connecting semiconductors to biological molecules like DNA and antibodies. This technology could lead to new gene therapy procedures, cancer treatments and other medical applications. She will also discuss technologies made possible by organizing small semiconductor particles called quantum dots, materials that exhibit a rich variety of phenomena that are size and shape dependent. Development of these new materials that harnesses the unique properties of materials at the 1-100 nanometer scale resulted in the new field of nanotechnology that currently affects many applications in technological and medical fields.

  1. Carbon-based electrocatalysts for advanced energy conversion and storage

    PubMed Central

    Zhang, Jintao; Xia, Zhenhai; Dai, Liming

    2015-01-01

    Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries. Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER in fuel cells and batteries. We present a critical review on the recent advances in carbon-based metal-free catalysts for fuel cells and metal-air batteries, and discuss the perspectives and challenges in this rapidly developing field of practical significance. PMID:26601241

  2. Candidate advanced energy storage concepts for multimegawatt burst power systems

    NASA Astrophysics Data System (ADS)

    Boretz, John E.; Sollo, Charles

    Three candidate advanced energy storage systems are reviewed and compared with the Thermionic Operating Reactor (THOR) concept. The three systems considered are the flywheel generator, the lithium-metal sulfide battery and the alkaline fuel cell. From a minimum mass viewpoint, only the regenerative fuel cell (RFC) can result in a lighter system than THOR. Because of its lower operating temperature, as compared to THOR, a considerable reduction in materials problems is to be expected when compared to the extremely high operating temperatures of the THOR system. Frozen heat pipes and their impact on response time as well as the complexity of the required retraction/extension mechanism of the THOR system would tend to place the RFC system in a much lower category of development risk. Finally, if spot shielding of sensitive electronic and power conditioning equipment becomes necessary for the reactor radiation environment of the THOR system, the weight advantage of the RFC system may become even greater.

  3. Advanced Power Batteries for Renewable Energy Applications 3.09

    SciTech Connect

    Shane, Rodney

    2011-12-01

    This report describes the research that was completed under project title Advanced Power Batteries for Renewable Energy Applications 3.09, Award Number DE-EE0001112. The report details all tasks described in the Statement of Project Objectives (SOPO). The SOPO includes purchasing of test equipment, designing tooling, building cells and batteries, testing all variables and final evaluation of results. The SOPO is included. There were various types of tests performed during the project, such as; gas collection, float current monitoring, initial capacity, high rate partial state of charge (HRPSoC), hybrid pulse power characterization (HPPC), high rate capacity, corrosion, software modeling and solar life cycle tests. The grant covered a period of two years starting October 1, 2009 and ending September 30, 2011.

  4. Carbon-based electrocatalysts for advanced energy conversion and storage.

    PubMed

    Zhang, Jintao; Xia, Zhenhai; Dai, Liming

    2015-08-01

    Oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) play curial roles in electrochemical energy conversion and storage, including fuel cells and metal-air batteries. Having rich multidimensional nanoarchitectures [for example, zero-dimensional (0D) fullerenes, 1D carbon nanotubes, 2D graphene, and 3D graphite] with tunable electronic and surface characteristics, various carbon nanomaterials have been demonstrated to act as efficient metal-free electrocatalysts for ORR and OER in fuel cells and batteries. We present a critical review on the recent advances in carbon-based metal-free catalysts for fuel cells and metal-air batteries, and discuss the perspectives and challenges in this rapidly developing field of practical significance. PMID:26601241

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

    SciTech Connect

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

    2011-09-29

    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.

  6. Development of the Advanced Energy Design Guide for K-12 Schools -- 50% Energy Savings

    SciTech Connect

    Bonnema, E.; Leach, M.; Pless, S.; Torcellini, P.

    2013-02-01

    This Technical Support Document (TSD) describes the process and methodology for the development of the Advanced Energy Design Guide for K-12 School Buildings: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-K12) (ASHRAE et al. 2011a). The AEDG-K12 provides recommendations for achieving 50% whole-building energy savings in K-12 schools over levels achieved by following ANSI/ASHRAE/IESNA Standard 90.1-2004, Energy Standard for Buildings Except Low-Rise Residential Buildings (Standard 90.1-2004) (ASHRAE 2004b). The AEDG-K12 was developed in collaboration with the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Illuminating Engineering Society of North America (IES), the U.S. Green Building Council (USGBC), and the U.S. Department of Energy (DOE).

  7. Analysis of prompt fission neutrons in 235U(nth,f) and fission fragment distributions for the thermal neutron induced fission of 234U

    NASA Astrophysics Data System (ADS)

    Al-Adili, A.; Tarrío, D.; Hambsch, F.-J.; Göök, A.; Jansson, K.; Solders, A.; Rakopoulos, V.; Gustafsson, C.; Lantz, M.; Mattera, A.; Oberstedt, S.; Prokofiev, A. V.; Vidali, M.; Österlund, M.; Pomp, S.

    2016-06-01

    This paper presents the ongoing analysis of two fission experiments. Both projects are part of the collaboration between the nuclear reactions group at Uppsala and the JRC-IRMM. The first experiment deals with the prompt fission neutron multiplicity in the thermal neutron induced fission of 235U(n,f). The second, on the fission fragment properties in the thermal fission of 234U(n,f). The prompt fission neutron multiplicity has been measured at the JRC-IRMM using two liquid scintillators in coincidence with an ionization chamber. The first experimental campaign focused on 235U(nth,f) whereas a second experimental campaign is foreseen later for the same reaction at 5.5 MeV. The goal is to investigate how the so-called sawtooth shape changes as a function of fragment mass and excitation energy. Some harsh experimental conditions were experienced due to the large radiation background. The solution to this will be discussed along with preliminary results. In addition, the analysis of thermal neutron induced fission of 234U(n,f) will be discussed. Currently analysis of data is ongoing, originally taken at the ILL reactor. The experiment is of particular interest since no measurement exist of the mass and energy distributions for this system at thermal energies. One main problem encountered during analysis was the huge background of 235U(nth,f). Despite the negligible isotopic traces in the sample, the cross section difference is enormous. Solution to this parasitic background will be highlighted.

  8. On the origin of the Moon by rotational fission

    NASA Technical Reports Server (NTRS)

    Binder, A. B.

    1984-01-01

    Consistent with the current understanding of the Moon's bulk composition, internal structure, seismic and tectonic characteristics, evidence is discussed which suggests that the Moon originated by fission. The concepts discussed are: (1) all stars are members of close or contact binary systems; (2) advances in dynamical studies of the fission hypothesis show that stellar bodies also undergo fission; (3) the newly formed proto moon would have lost a large fraction of its original mass via mass transfer; and (4) due to the foregoing concepts the result would be a moon of terrestrial mantle material which was depleted in both metallic iron and volatiles.

  9. Uranium arc fission reactor for space propulsion

    NASA Astrophysics Data System (ADS)

    Watanabe, Yoichi; Maya, Isaac; Vitali, Juan; Appelbaum, Jacob; Schneider, Richard T.

    Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium ionization by fission fragments can lead to an attractive propulsion system which has a higher specific impulse than a solid core propulsion system and higher thrust than an electric propulsion system. A preliminary study indicates that a system with 300 MW of fission power can achieve a gas exhaust velocity of 18,000 m/sec and a thrust of 10,000 Newtons utilizing a magnetohydrodynamic generator and accelerator. An experimental program is underway to examine the major mass and energy transfer issues.

  10. Uranium arc fission reactor for space propulsion

    NASA Astrophysics Data System (ADS)

    Watanabe, Yoichi; Maya, Isaac; Vitali, Juan; Appelbaum, Jacob; Schneider, Richard T.

    1991-01-01

    Combining the proven technology of solid core reactors with uranium arc confinement and non-equilibrium ionization by fission fragments can lead to an attractive propulsion system which has a higher specific impulse than a solid core propulsion system and higher thrust than an electric propulsion systems. A preliminary study indicates that a system with 300 MW of fission power can achieve a gas exhaust velocity of 18,000 m/sec and a thrust of 10,000 Newtons utilizing a magnetohydrodynamic generator and accelerator. An experimental program is underway to examine the major mass and energy transfer issues.

  11. Uncertainty Quantification on Prompt Fission Neutrons Spectra

    SciTech Connect

    Talou, P. Madland, D.G.; Kawano, T.

    2008-12-15

    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.

  12. Transfer-induced fission of superheavy nuclei

    SciTech Connect

    Adamian, G. G.; Antonenko, N. V.; Zubov, A. S.; Sargsyan, V. V.; Scheid, W.

    2010-07-15

    Possibilities of transfer-induced fission of new isotopes of superheavy nuclei with charge numbers 103-108 are studied for the first time in the reactions {sup 48}Ca+{sup 244,246,248}Cm at energies near the corresponding Coulomb barriers. The predicted cross sections are found to be measurable with the detection of three-body final states.

  13. Advanced materials and concepts for energy storage devices

    NASA Astrophysics Data System (ADS)

    Teng, Shiang Jen

    Over the last decade, technological progress and advances in the miniaturization of electronic devices have increased demands for light-weight, high-efficiency, and carbon-free energy storage devices. These energy storage devices are expected to play important roles in automobiles, the military, power plants, and consumer electronics. Two main types of electrical energy storage systems studied in this research are Li ion batteries and supercapacitors. Several promising solid state electrolytes and supercapacitor electrode materials are investigated in this research. The first section of this dissertation is focused on the novel results on pulsed laser annealing of Li7La3Zr2O12 (LLZO). LLZO powders with a tetragonal structure were prepared by a sol-gel technique, then a pulsed laser annealing process was employed to convert the tetragonal powders to cubic LLZO without any loss of lithium. The second section of the dissertation reports on how Li5La 3Nb2O12 (LLNO) was successfully synthesized via a novel molten salt synthesis (MSS) method at the relatively low temperature of 900°C. The low sintering temperature prevented the loss of lithium that commonly occurs during synthesis using conventional solid state or wet chemical reactions. The second type of energy storage device studied is supercapacitors. Currently, research on supercapacitors is focused on increasing their energy densities and lowering their overall production costs by finding suitable electrode materials. The third section of this dissertation details how carbonized woods electrodes were used as supercapacitor electrode materials. A high energy density of 45.6 Wh/kg and a high power density of 2000 W/kg were obtained from the supercapacitor made from carbonized wood electrodes. The high performance of the supercapacitor was discovered to originate from the hierarchical porous structures of the carbonized wood. Finally, the fourth section of this dissertation is on the electrochemical effects of

  14. Validation of ATR Fission Power Deposition Fraction in HEU and LEU Fuel Plates

    SciTech Connect

    G. S. Chang

    2008-09-01

    The Advanced Test Reactor (ATR) is a high power (250 MW), high neutron flux research reactor operating in the United States. Powered with highly enriched uranium (HEU), the ATR has a maximum unperturbed thermal neutron flux rating of 1.0 x 1015 n/cm2–s. Because of its high power and large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting an HEU driven reactor to a low-enriched core. A detailed plate-by-plate MCNP ATR full core model has been developed and validated for the low-enriched uranium (LEU) fuel conversion feasibility study. Using this model, an analysis has been performed to determine the LEU density and U-235 enrichment required in the fuel meat to yield equivalent K-eff versus effective full power days (EFPDs) between the HEU and LEU cores. This model has also been used to optimize U-235 content of the LEU core, minimizing the differences in K-eff and heat flux profile between the HEU and LEU cores at 115 MW total core power for 125 EFPDs. The LEU core conversion feasibility study evaluated foil type (U-10Mo) fuel with the LEU reference design of 19.7 wt% U-235 enrichment. The LEU reference design has a fixed fuel meat thickness of 0.330 mm and can sustain the same operating cycle length as the HEU fuel. Heat flux and fission power density are parameters that are proportional to the fraction of fission power deposited in fuel. Thus, the accurate determination of the fraction of fission power deposited in the fuel is important to ATR nuclear safety. In this work, a new approach was developed and validated, the Tally Fuel Cells Only (TFCO) method. This method calculates and compares the fission power deposition fraction between HEU and LEU fuel plates. Due to the high density of the U-10Mo LEU fuel, the fission ?-energy deposition fraction is 37.12%, which is larger than the HEU’s ?-energy deposition fraction of 19.7%. As a result, the fuel decay heat cooling will need to be improved

  15. Fission enhanced diffusion of uranium in zirconia

    NASA Astrophysics Data System (ADS)

    Bérerd, N.; Chevarier, A.; Moncoffre, N.; Sainsot, Ph.; Faust, H.; Catalette, H.

    2005-11-01

    This paper deals with the comparison between thermal and Fission Enhanced Diffusion (FED) of uranium into zirconia, representative of the inner face of cladding tubes. The experiments under irradiation are performed at the Institut Laue Langevin (ILL) in Grenoble using the Lohengrin spectrometer. A thin 235UO2 layer in direct contact with an oxidised zirconium foil is irradiated in the ILL high flux reactor. The fission product flux is about 1011 ions cm-2 s-1 and the target temperature is measured by an IR pyrometer. A model is proposed to deduce an apparent uranium diffusion coefficient in zirconia from the energy distribution broadening of two selected fission products. It is found to be equal to 10-15 cm2 s-1 at 480 °C and compared to uranium thermal diffusion data in ZrO2 in the same pressure and temperature conditions. The FED results are analysed in comparison with literature data.

  16. Process for treating fission waste

    DOEpatents

    Rohrmann, Charles A.; Wick, Oswald J.

    1983-01-01

    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.

  17. ICENES '91:Sixth international conference on emerging nuclear energy systems

    SciTech Connect

    Not Available

    1991-01-01

    This document contains the program and abstracts of the sessions at the Sixth International Conference on Emerging Nuclear Energy Systems held June 16--21, 1991 at Monterey, California. These sessions included: The plenary session, fission session, fission and nonelectric session, poster session 1P; (space propulsion, space nuclear power, electrostatic confined fusion, fusion miscellaneous, inertial confinement fusion, [mu]-catalyzed fusion, and cold fusion); Advanced fusion session, space nuclear session, poster session 2P, (nuclear reactions/data, isotope separation, direct energy conversion and exotic concepts, fusion-fission hybrids, nuclear desalting, accelerator waste-transmutation, and fusion-based chemical recycling); energy policy session, poster session 3P (energy policy, magnetic fusion reactors, fission reactors, magnetically insulated inertial fusion, and nuclear explosives for power generation); exotic energy storage and conversion session; and exotic energy storage and conversion; review and closing session.

  18. Overview of fission yeast septation.

    PubMed

    Pérez, Pilar; Cortés, Juan C G; Martín-García, Rebeca; Ribas, Juan C

    2016-09-01

    Cytokinesis is the final process of the vegetative cycle, which divides a cell into two independent daughter cells once mitosis is completed. In fungi, as in animal cells, cytokinesis requires the formation of a cleavage furrow originated by constriction of an actomyosin ring which is connected to the plasma membrane and causes its invagination. Additionally, because fungal cells have a polysaccharide cell wall outside the plasma membrane, cytokinesis requires the formation of a septum coincident with the membrane ingression. Fission yeast Schizosaccharomyces pombe is a unicellular, rod-shaped fungus that has become a popular model organism for the study of actomyosin ring formation and constriction during cell division. Here we review the current knowledge of the septation and separation processes in this fungus, as well as recent advances in understanding the functional interaction between the transmembrane enzymes that build the septum and the actomyosin ring proteins. PMID:27155541

  19. Analysis of aqueous and organic fission-product solutions by energy-dispersive x-ray fluorescence

    SciTech Connect

    Brooksbank, R.D.; Stewart, J.H. Jr.

    1981-01-01

    Because of a revival of interest in reprocessing spent nuclear reactor fuel, ORNL is re-evaluating existing data on extractions. Organic degradation products and new organic extractant systems must also be investigated. Analysis of these solutions present several problems for the analytical chemist. Conventional wet chemical techniques usually require aqueous solutions. Organic solutions must be stripped or wet ashed to convert them to an aqueous system. Stripping is not always quantitative, and the high phosphorus content of organic extractants makes wet ashing difficult. Radiolysis degrades many organic solutions. In aqueous solutions, low acid concentrations cause Pu to polymerize and Zr and Mo to form colloids or precipitate; therefore, sample pretreatment becomes necessary. Energy dispersive x-ray fluorescence (XRF) is a multi-element technique, unaffected by chemical states, capable of analyzing both aqueous and organic solutions. Thie technique has been applied to the determination of U, Pu, Th, Mo, Zr and Re in cold flow sheet development.

  20. Measurements of High-energy Excited States and γ-rays of Fission Products with a 4π Clover Detector

    SciTech Connect

    Shima, Y.; Kojima, Y.; Hayashi, H.; Taniguchi, A.; Shibata, M.

    2014-06-15

    Gamma-rays in the β-decay of {sup 147}La and {sup 145}Ba were measured using a 4π clover detector to identify high-energy excited levels and γ-rays. In order to determine γ-ray intensities, an efficiency calibration was carried out using single and multiple γ-ray emitters. Applying appropriate coincidence summing corrections, the peak efficiency was experimentally determined from 50 to 3200 keV with 3% accuracy. Through analyses of sum peaks and cascade relations of γ-rays, we newly identified 170 levels between 924 and 3568 keV, and more than 930 γ-rays in the decay of {sup 147}La, and 70 levels between 973 and 3703 keV, and 250 γ-rays in the decay of {sup 145}Ba.

  1. Fission Surface Power Technology Development Update

    NASA Technical Reports Server (NTRS)

    Palac, Donald T.; Mason, Lee S.; Houts, Michael G.; Harlow, Scott

    2011-01-01

    Power is a critical consideration in planning exploration of the surfaces of the Moon, Mars, and places beyond. Nuclear power is an important option, especially for locations in the solar system where sunlight is limited or environmental conditions are challenging (e.g., extreme cold, dust storms). NASA and the Department of Energy are maintaining the option for fission surface power for the Moon and Mars by developing and demonstrating technology for a fission surface power system. The Fission Surface Power Systems project has focused on subscale component and subsystem demonstrations to address the feasibility of a low-risk, low-cost approach to space nuclear power for surface missions. Laboratory demonstrations of the liquid metal pump, reactor control drum drive, power conversion, heat rejection, and power management and distribution technologies have validated that the fundamental characteristics and performance of these components and subsystems are consistent with a Fission Surface Power preliminary reference concept. In addition, subscale versions of a non-nuclear reactor simulator, using electric resistance heating in place of the reactor fuel, have been built and operated with liquid metal sodium-potassium and helium/xenon gas heat transfer loops, demonstrating the viability of establishing system-level performance and characteristics of fission surface power technologies without requiring a nuclear reactor. While some component and subsystem testing will continue through 2011 and beyond, the results to date provide sufficient confidence to proceed with system level technology readiness demonstration. To demonstrate the system level readiness of fission surface power in an operationally relevant environment (the primary goal of the Fission Surface Power Systems project), a full scale, 1/4 power Technology Demonstration Unit (TDU) is under development. The TDU will consist of a non-nuclear reactor simulator, a sodium-potassium heat transfer loop, a power

  2. Pulsed Fission Propulsion Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the 1960's U.S. Government laboratories, under Project Orion, investigated a pulsed nuclear fission propulsion system. Small nuclear pulse units would be sequentially discharged from the aft end of the vehicle. A blast shield and shock absorber system would protect the crew and convert the shock loads into a continuous propusive force.

  3. Pulsed Fission Propulsion Concept

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the 1960's U.S. Government laboratories, under Project Orion, investigated a pulsed nuclear fission propulsion system. Small nuclear pulse units would be sequentially discharged from the aft end of the vehicle. A blast shield and shock absorber system would protect the crew and convert the shock loads into a continuous propulsive force.

  4. Advanced Manufacturing for a U.S. Clean Energy Economy (Fact Sheet)

    SciTech Connect

    Not Available

    2012-03-01

    This fact sheet is an overview of the U.S. Department of Energy's Advanced Manufacturing Office. Manufacturing is central to our economy, culture, and history. The industrial sector produces 11% of U.S. gross domestic product (GDP), employs 12 million people, and generates 57% of U.S. export value. However, U.S. industry consumes about one-third of all energy produced in the United States, and significant cost-effective energy efficiency and advanced manufacturing opportunities remain unexploited. As a critical component of the National Innovation Policy for Advanced Manufacturing, the U.S. Department of Energy's (DOE's) Advanced Manufacturing Office (AMO) is focused on creating a fertile environment for advanced manufacturing innovation, enabling vigorous domestic development of transformative manufacturing technologies, promoting coordinated public and private investment in precompetitive advanced manufacturing technology infrastructure, and facilitating the rapid scale-up and market penetration of advanced manufacturing technologies.

  5. Potential Operating Orbits for Fission Electric Propulsion Systems Driven by the SAFE-400

    NASA Technical Reports Server (NTRS)

    Houts, Mike; Kos, Larry; Poston, David; Rodgers, Stephen L. (Technical Monitor)

    2002-01-01

    Safety must be ensured during all phases of space fission system design, development, fabrication, launch, operation, and shutdown. One potential space fission system application is fission electric propulsion (FEP), in which fission energy is converted into electricity and used to power high efficiency (Isp greater than 3000s) electric thrusters. For these types of systems it is important to determine which operational scenarios ensure safety while allowing maximum mission performance and flexibility. Space fission systems are essentially nonradioactive at launch, prior to extended operation at high power. Once high power operation begins, system radiological inventory steadily increases as fission products build up. For a given fission product isotope, the maximum radiological inventory is typically achieved once the system has operated for a length of time equivalent to several half-lives. After that time, the isotope decays at the same rate it is produced, and no further inventory builds in. For an FEP mission beginning in Earth orbit, altitude and orbital lifetime increase as the propulsion system operates. Two simultaneous effects of fission propulsion system operation are thus (1) increasing fission product inventory and (2) increasing orbital lifetime. Phrased differently, as fission products build up, more time is required for the fission products to naturally convert back into non-radioactive isotopes. Simultaneously, as fission products build up, orbital lifetime increases, providing more time for the fission products to naturally convert back into non-radioactive isotopes. Operational constraints required to ensure safety can thus be quantified.

  6. Formation of asteroid pairs by rotational fission.

    PubMed

    Pravec, P; Vokrouhlický, D; Polishook, D; Scheeres, D J; Harris, A W; Galád, A; Vaduvescu, O; Pozo, F; Barr, A; Longa, P; Vachier, F; Colas, F; Pray, D P; Pollock, J; Reichart, D; Ivarsen, K; Haislip, J; Lacluyze, A; Kusnirák, P; Henych, T; Marchis, F; Macomber, B; Jacobson, S A; Krugly, Yu N; Sergeev, A V; Leroy, A

    2010-08-26

    Pairs of asteroids sharing similar heliocentric orbits, but not bound together, were found recently. Backward integrations of their orbits indicated that they separated gently with low relative velocities, but did not provide additional insight into their formation mechanism. A previously hypothesized rotational fission process may explain their formation-critical predictions are that the mass ratios are less than about 0.2 and, as the mass ratio approaches this upper limit, the spin period of the larger body becomes long. Here we report photometric observations of a sample of asteroid pairs, revealing that the primaries of pairs with mass ratios much less than 0.2 rotate rapidly, near their critical fission frequency. As the mass ratio approaches 0.2, the primary period grows long. This occurs as the total energy of the system approaches zero, requiring the asteroid pair to extract an increasing fraction of energy from the primary's spin in order to escape. We do not find asteroid pairs with mass ratios larger than 0.2. Rotationally fissioned systems beyond this limit have insufficient energy to disrupt. We conclude that asteroid pairs are formed by the rotational fission of a parent asteroid into a proto-binary system, which subsequently disrupts under its own internal system dynamics soon after formation.

  7. Spontaneous fission of /sup 259/Fm

    SciTech Connect

    Hulet, E.K.; Lougheed, R.W.; Landrum, J.H.; Wild, J.F.; Hoffman, D.C.; Weber, J.; Wilhelmy, J.B.

    1980-03-01

    A 1.5-s spontaneous fission activity has been produced by irradiating /sup 257/Fm with 16-MeV tritons. On the basis of formation cross sections, fission half-life systematics, and the identification of other possible products, this 1.5-s activity has been attributed to /sup 259/Fm formed by the reaction /sup 257/Fm(t,p)/sup 259/Fm. /sup 259/Fm is the heaviest known isotope of Fm and has more neutrons than any other nuclide thus far identified. This measurement of the spontaneous fission of /sup 259/Fm is the first to show a narrow, predominantly symmetric, mass division from spontaneous fission. It is accompanied by a very high kinetic energy, the most probable total kinetic energy being 242 +- 6 MeV. These features show a marked acceleration in the trend toward more symmetric mass division and higher total kinetic energies than have been observed previously for the Fm isotopes as the mass increased.

  8. Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency

    SciTech Connect

    Cook, B. A.; Harringa, J. L.; Russel, A. M.

    2012-12-01

    This report summarizes the work performed by an Ames-led project team under a 4-year DOE-ITP sponsored project titled, 'Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency.' The Report serves as the project deliverable for the CPS agreement number 15015. The purpose of this project was to develop and commercialize a family of lightweight, bulk composite materials that are highly resistant to degradation by erosive and abrasive wear. These materials, based on AlMgB{sub 14}, are projected to save over 30 TBtu of energy per year when fully implemented in industrial applications, with the associated environmental benefits of eliminating the burning of 1.5 M tons/yr of coal and averting the release of 4.2 M tons/yr of CO{sub 2} into the air. This program targeted applications in the mining, drilling, machining, and dry erosion applications as key platforms for initial commercialization, which includes some of the most severe wear conditions in industry. Production-scale manufacturing of this technology has begun through a start-up company, NewTech Ceramics (NTC). This project included providing technical support to NTC in order to facilitate cost-effective mass production of the wear-resistant boride components. Resolution of issues related to processing scale-up, reduction in energy intensity during processing, and improving the quality and performance of the composites, without adding to the cost of processing were among the primary technical focus areas of this program. Compositional refinements were also investigated in order to achieve the maximum wear resistance. In addition, synthesis of large-scale, single-phase AlMgB{sub 14} powder was conducted for use as PVD sputtering targets for nanocoating applications.

  9. Advanced carbon manufacturing for energy and biological applications

    NASA Astrophysics Data System (ADS)

    Turon Teixidor, Genis

    The science of miniaturization has experienced revolutionary advances during the last decades, witnessing the development of the Integrated Circuit and the emergence of MEMS and Nanotechnology. Particularly, MEMS technology has pioneered the use of non-traditional materials in microfabrication by including polymers, ceramics and composites to the well known list of metals and semiconductors. One of the latest additions to this set of materials is carbon, which represents a very important inclusion given its significance in electrochemical energy conversion systems and in applications where it is used as sensor probe material. For these applications, carbon is optimal in several counts: It has a wide electrochemical stability window, good electrical and thermal conductivity, high corrosion resistance and mechanical stability, and is available in high purity at a low cost. Furthermore carbon is biocompatible. This thesis presents several microfabricated devices that take advantage of these properties. The thesis has two clearly differentiated parts. In the first one, applications of micromachined carbon in the field of energy conversion and energy storage are presented. These applications include lithium ion micro batteries and the development of new carbon electrodes with fractal geometries. In the second part, the focus shifts to biological applications. First, the study of the interaction of living cells with micromachined carbon is presented, followed by the description of a sensor based on interdigitated nano-electrode arrays, and finally the development of the new instrumentation needed to address arrays of carbon electrodes, a multiplexed potentiostat. The underlying theme that connects all these seemingly different topics is the use of carbon microfabrication techniques in electrochemical systems.

  10. Advanced proton-exchange materials for energy efficient fuel cells.

    SciTech Connect

    Fujimoto, Cy H.; Grest, Gary Stephen; Hickner, Michael A.; Cornelius, Christopher James; Staiger, Chad Lynn; Hibbs, Michael R.

    2005-12-01

    The ''Advanced Proton-Exchange Materials for Energy Efficient Fuel Cells'' Laboratory Directed Research and Development (LDRD) project began in October 2002 and ended in September 2005. This LDRD was funded by the Energy Efficiency and Renewable Energy strategic business unit. The purpose of this LDRD was to initiate the fundamental research necessary for the development of a novel proton-exchange membranes (PEM) to overcome the material and performance limitations of the ''state of the art'' Nafion that is used in both hydrogen and methanol fuel cells. An atomistic modeling effort was added to this LDRD in order to establish a frame work between predicted morphology and observed PEM morphology in order to relate it to fuel cell performance. Significant progress was made in the area of PEM material design, development, and demonstration during this LDRD. A fundamental understanding involving the role of the structure of the PEM material as a function of sulfonic acid content, polymer topology, chemical composition, molecular weight, and electrode electrolyte ink development was demonstrated during this LDRD. PEM materials based upon random and block polyimides, polybenzimidazoles, and polyphenylenes were created and evaluated for improvements in proton conductivity, reduced swelling, reduced O{sub 2} and H{sub 2} permeability, and increased thermal stability. Results from this work reveal that the family of polyphenylenes potentially solves several technical challenges associated with obtaining a high temperature PEM membrane. Fuel cell relevant properties such as high proton conductivity (>120 mS/cm), good thermal stability, and mechanical robustness were demonstrated during this LDRD. This report summarizes the technical accomplishments and results of this LDRD.

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

    SciTech Connect

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

    1986-01-01

    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.

  12. Advanced Energy Retrofit Guide (AERG): Practical Ways to Improve Energy Performance; Healthcare Facilities (Book)

    SciTech Connect

    Hendron, R.; Leach, M.; Bonnema, E.; Shekhar, D.; Pless, S.

    2013-09-01

    The Advanced Energy Retrofit Guide for Healthcare Facilities is part of a series of retrofit guides commissioned by the U.S. Department of Energy. By presenting general project planning guidance as well as detailed descriptions and financial payback metrics for the most important and relevant energy efficiency measures (EEMs), the guides provide a practical roadmap for effectively planning and implementing performance improvements in existing buildings. The Advanced Energy Retrofit Guides (AERGs) are intended to address key segments of the U.S. commercial building stock: retail stores, office buildings, K-12 schools, grocery stores, and healthcare facilities. The guides' general project planning considerations are applicable nationwide; the energy and cost savings estimates for recommended EEMs were developed based on energy simulations and cost estimates for an example hospital tailored to five distinct climate regions. These results can be extrapolated to other U.S. climate zones. Analysis is presented for individual EEMs, and for packages of recommended EEMs for two project types: existing building commissioning projects that apply low-cost and no-cost measures, and whole-building retrofits involving more capital-intensive measures.

  13. Embrace the Dark Side: Advancing the Dark Energy Survey

    NASA Astrophysics Data System (ADS)

    Suchyta, Eric

    The Dark Energy Survey (DES) is an ongoing cosmological survey intended to study the properties of the accelerated expansion of the Universe. In this dissertation, I present work of mine that has advanced the progress of DES. First is an introduction, which explores the physics of the cosmos, as well as how DES intends to probe it. Attention is given to developing the theoretical framework cosmologists use to describe the Universe, and to explaining observational evidence which has furnished our current conception of the cosmos. Emphasis is placed on the dark sector - dark matter and dark energy - the content of the Universe not explained by the Standard Model of particle physics. As its name suggests, the Dark Energy Survey has been specially designed to measure the properties of dark energy. DES will use a combination of galaxy cluster, weak gravitational lensing, angular clustering, and supernovae measurements to derive its state of the art constraints, each of which is discussed in the text. The work described in this dissertation includes science measurements directly related to the first three of these probes. The dissertation presents my contributions to the readout and control system of the Dark Energy Camera (DECam); the name of this software is SISPI. SISPI uses client-server and publish-subscribe communication patterns to coordinate and command actions among the many hardware components of DECam - the survey instrument for DES, a 570 megapixel CCD camera, mounted at prime focus of the Blanco 4-m Telescope. The SISPI work I discuss includes coding applications for DECam's filter changer mechanism and hexapod, as well as developing the Scripts Editor, a GUI application for DECam users to edit and export observing sequence SISPI can load and execute. Next, the dissertation describes the processing of early DES data, which I contributed. This furnished the data products used in the first-completed DES science analysis, and contributed to improving the

  14. Pairing-induced speedup of nuclear spontaneous fission

    SciTech Connect

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

    2014-12-22

    Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these 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 264Fm and 240Pu 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 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case for 240Pu, 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. As a result, 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.

  15. Pairing-induced speedup of nuclear spontaneous fission

    DOE PAGES

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

    2014-12-22

    Collective inertia is strongly influenced at the level crossing at which the quantum system changes its microscopic configuration diabatically. Pairing correlations tend to make the large-amplitude nuclear collective motion more adiabatic by reducing the effect of these 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 264Fm and 240Pu 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-dependentmore » 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 264Fm, where the effect of triaxiality on the fission barrier is large, the geometry of the fission pathway in the space of the shape degrees of freedom is weakly impacted by pairing. This is not the case for 240Pu, 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. As a result, 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.« less

  16. Neutron induced fission cross section of {sup 237}Np from 100 keV to 200 MeV

    SciTech Connect

    Tovesson, F.; Hill, T. S.

    2007-03-15

    An experimental program at Los Alamos Neutron Science Center (LANSCE) has been developed to precisely measure fission cross sections over ten decades in incident neutron energy for a range of actinides relevant to advanced nuclear reactor designs and transmutation concepts. The first completed measurement is of {sup 237}Np(n,f), and the above-reaction-threshold part of the measurement is reported here. The result is in close agreement with ENDF/B-VI in the energy region of first- and second-chance fission. The cross section ratio to {sup 235}U is shown to be constant from 30 MeV to the highest measured energy of 200 MeV.

  17. The discovery and spontaneous fission properties of /sup 262/No

    SciTech Connect

    Lougheed, R.W.; Hulet, E.K.; Wild, J.F.; Moody, K.J.; Dougan, R.J.; Gannett, C.M.; Henderson, R.A.; Hoffman, D.C.; Lee, D.M.

    1989-04-19

    We have discovered /sup 262/No, as the electron capture daughter of /sup 262/Lr(t/sub 1/2/ = 216 m). This new isotope of nobelium decays by spontaneous fission with about a 5-ms half-life which is several orders of magnitude longer than recent theoretical estimates. We measured a sharply symmetric fission-fragment mass division and a bimodal total kinetic energy distribution; the high-energy symmetric-fission path was most abundant. /sup 262/No is the first nuclide with 160 neutrons to be discovered and is the closest to the N = 162 neutron subshell for which enhanced stability is predicted. 14 refs., 3 figs.

  18. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Stoyer, M. A.; Wu, C. Y.; Fowler, M. M.; Becker, J. A.; Bond, E. M.; Couture, A.; Haight, R. C.; Haslett, R. J.; Henderson, R. A.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2009-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for 241Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for 243Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on 242mAm will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,γ) events from (n,f) events. The first direct observation of neutron capture on 242mAm in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  19. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    SciTech Connect

    Jandel, Marian

    2008-01-01

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) from (n,f) events. The first evidence of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  20. Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE

    SciTech Connect

    Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Couture, A.; Haight, R. C.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Stoyer, M. A.; Wu, C. Y.; Becker, J. A.; Haslett, R. J.; Henderson, R. A.

    2009-01-28

    Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) events from (n,f) events. The first direct observation of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

  1. Fission Product Yield Study of 235U, 238U and 239Pu Using Dual-Fission Ionization Chambers

    NASA Astrophysics Data System (ADS)

    Bhatia, C.; Fallin, B.; Howell, C.; Tornow, W.; Gooden, M.; Kelley, J.; Arnold, C.; Bond, E.; Bredeweg, T.; Fowler, M.; Moody, W.; Rundberg, R.; Rusev, G.; Vieira, D.; Wilhelmy, J.; Becker, J.; Macri, R.; Ryan, C.; Sheets, S.; Stoyer, M.; Tonchev, A.

    2014-05-01

    To resolve long-standing differences between LANL and LLNL regarding the correct fission basis for analysis of nuclear test data [M.B. Chadwick et al., Nucl. Data Sheets 111, 2891 (2010); H. Selby et al., Nucl. Data Sheets 111, 2891 (2010)], a collaboration between TUNL/LANL/LLNL has been established to perform high-precision measurements of neutron induced fission product yields. The main goal is to make a definitive statement about the energy dependence of the fission yields to an accuracy better than 2-3% between 1 and 15 MeV, where experimental data are very scarce. At TUNL, we have completed the design, fabrication and testing of three dual-fission chambers dedicated to 235U, 238U, and 239Pu. The dual-fission chambers were used to make measurements of the fission product activity relative to the total fission rate, as well as for high-precision absolute fission yield measurements. The activation method was employed, utilizing the mono-energetic neutron beams available at TUNL. Neutrons of 4.6, 9.0, and 14.5 MeV were produced via the 2H(d,n)3He reaction, and for neutrons at 14.8 MeV, the 3H(d,n)4He reaction was used. After activation, the induced γ-ray activity of the fission products was measured for two months using high-resolution HPGe detectors in a low-background environment. Results for the yield of seven fission fragments of 235U, 238U, and 239Pu and a comparison to available data at other energies are reported. For the first time results are available for neutron energies between 2 and 14 MeV.

  2. General Description of Fission Observables: GEF Model Code

    NASA Astrophysics Data System (ADS)

    Schmidt, K.-H.; Jurado, B.; Amouroux, C.; Schmitt, C.

    2016-01-01

    The GEF ("GEneral description of Fission observables") model code is documented. It describes the observables for spontaneous fission, neutron-induced fission and, more generally, for fission of a compound nucleus from any other entrance channel, with given excitation energy and angular momentum. The GEF model is applicable for a wide range of isotopes from Z = 80 to Z = 112 and beyond, up to excitation energies of about 100 MeV. The results of the GEF model are compared with fission barriers, fission probabilities, fission-fragment mass- and nuclide distributions, isomeric ratios, total kinetic energies, and prompt-neutron and prompt-gamma yields and energy spectra from neutron-induced and spontaneous fission. Derived properties of delayed neutrons and decay heat are also considered. The GEF model is based on a general approach to nuclear fission that explains a great part of the complex appearance of fission observables on the basis of fundamental laws of physics and general properties of microscopic systems and mathematical objects. The topographic theorem is used to estimate the fission-barrier heights from theoretical macroscopic saddle-point and ground-state masses and experimental ground-state masses. Motivated by the theoretically predicted early localisation of nucleonic wave functions in a necked-in shape, the properties of the relevant fragment shells are extracted. These are used to determine the depths and the widths of the fission valleys corresponding to the different fission channels and to describe the fission-fragment distributions and deformations at scission by a statistical approach. A modified composite nuclear-level-density formula is proposed. It respects some features in the superfluid regime that are in accordance with new experimental findings and with theoretical expectations. These are a constant-temperature behaviour that is consistent with a considerably increased heat capacity and an increased pairing condensation energy that is

  3. Continuous-Energy Adjoint Flux and Perturbation Calculation using the Iterated Fission Probability Method in Monte Carlo Code TRIPOLI-4® and Underlying Applications

    NASA Astrophysics Data System (ADS)

    Truchet, G.; Leconte, P.; Peneliau, Y.; Santamarina, A.; Malvagi, F.

    2014-06-01

    Pile-oscillation experiments are performed in the MINERVE reactor at the CEA Cadarache to improve nuclear data accuracy. In order to precisely calculate small reactivity variations (<10 pcm) obtained in these experiments, a reference calculation need to be achieved. This calculation may be accomplished using the continuous-energy Monte Carlo code TRIPOLI-4® by using the eigenvalue difference method. This "direct" method has shown limitations in the evaluation of very small reactivity effects because it needs to reach a very small variance associated to the reactivity in both states. To answer this problem, it has been decided to implement the exact perturbation theory in TRIPOLI-4® and, consequently, to calculate a continuous-energy adjoint flux. The Iterated Fission Probability (IFP) method was chosen because it has shown great results in some other Monte Carlo codes. The IFP method uses a forward calculation to compute the adjoint flux, and consequently, it does not rely on complex code modifications but on the physical definition of the adjoint flux as a phase-space neutron importance. In the first part of this paper, the IFP method implemented in TRIPOLI-4® is described. To illustrate the effciency of the method, several adjoint fluxes are calculated and compared with their equivalent obtained by the deterministic code APOLLO-2. The new implementation can calculate angular adjoint flux. In the second part, a procedure to carry out an exact perturbation calculation is described. A single cell benchmark has been used to test the accuracy of the method, compared with the "direct" estimation of the perturbation. Once again the method based on the IFP shows good agreement for a calculation time far more inferior to the "direct" method. The main advantage of the method is that the relative accuracy of the reactivity variation does not depend on the magnitude of the variation itself, which allows us to calculate very small reactivity perturbations with high

  4. Monte Carlo simulation based toy model for fission process

    NASA Astrophysics Data System (ADS)

    Kurniadi, Rizal; Waris, Abdul; Viridi, Sparisoma

    2016-09-01

    Nuclear fission has been modeled notoriously using two approaches method, macroscopic and microscopic. This work will propose another approach, where the nucleus is treated as a toy model. The aim is to see the usefulness of particle distribution in fission yield calculation. Inasmuch nucleus is a toy, then the Fission Toy Model (FTM) does not represent real process in nature completely. The fission event in FTM is represented by one random number. The number is assumed as width of distribution probability of nucleon position in compound nuclei when fission process is started. By adopting the nucleon density approximation, the Gaussian distribution is chosen as particle distribution. This distribution function generates random number that randomizes distance between particles and a central point. The scission process is started by smashing compound nucleus central point into two parts that are left central and right central points. The yield is determined from portion of nuclei distribution which is proportional with portion of mass numbers. By using modified FTM, characteristic of particle distribution in each fission event could be formed before fission process. These characteristics could be used to make prediction about real nucleons interaction in fission process. The results of FTM calculation give information that the γ value seems as energy.

  5. Technical Support Document: Development of the Advanced Energy Design Guide for Large Hospitals - 50% Energy Savings

    SciTech Connect

    Bonnema, E.; Leach, M.; Pless, S.

    2013-06-01

    This Technical Support Document describes the process and methodology for the development of the Advanced Energy Design Guide for Large Hospitals: Achieving 50% Energy Savings Toward a Net Zero Energy Building (AEDG-LH) ASHRAE et al. (2011b). The AEDG-LH is intended to provide recommendations for achieving 50% whole-building energy savings in large hospitals over levels achieved by following Standard 90.1-2004. The AEDG-LH was created for a 'standard' mid- to large-size hospital, typically at least 100,000 ft2, but the strategies apply to all sizes and classifications of new construction hospital buildings. Its primary focus is new construction, but recommendations may be applicable to facilities undergoing total renovation, and in part to many other hospital renovation, addition, remodeling, and modernization projects (including changes to one or more systems in existing buildings).

  6. Compilation of fission product yields Vallecitos Nuclear Center

    SciTech Connect

    Rider, B.F.

    1980-01-01

    This document is the ninth in a series of compilations of fission yield data made at Vallecitos Nuclear Center in which fission yield measurements reported in the open literature and calculated charge distributions have been utilized to produce a recommended set of yields for the known fission products. The original data with reference sources, as well as the recommended yields are presented in tabular form for the fissionable nuclides U-235, Pu-239, Pu-241, and U-233 at thermal neutron energies; for U-235, U-238, Pu-239, and Th-232 at fission spectrum energies; and U-235 and U-238 at 14 MeV. In addition, U-233, U-236, Pu-240, Pu-241, Pu-242, Np-237 at fission spectrum energies; U-233, Pu-239, Th-232 at 14 MeV and Cf-252 spontaneous fission are similarly treated. For 1979 U234F, U237F, Pu249H, U234He, U236He, Pu238F, Am241F, Am243F, Np238F, and Cm242F yields were evaluated. In 1980, Th227T, Th229T, Pa231F, Am241T, Am241H, Am242Mt, Cm245T, Cf249T, Cf251T, and Es254T are also evaluated.

  7. Neutron induced capture and fission discrimination using calorimetric shape decomposition

    NASA Astrophysics Data System (ADS)

    Carrapiço, C.; Berthoumieux, E.; Dridi, W.; Gonçalves, I. F.; Gunsing, F.; Lampoudis, C.; Vaz, P.; n TOF Collaboration

    2013-03-01

    The neutron capture and fission cross-sections of 233U have been measured at the neutron time-of-flight facility n_TOF at CERN in the energy range from 1 eV to 1 keV using a high performance 4π BaF2 Total Absorption Calorimeter (TAC) as a detection device. In order to separate the contributions of neutron capture and neutron induced fission in the TAC, a methodology called Calorimetric Shape Decomposition (CSD) was developed. The CSD methodology is based on the study of the TAC's energy response for all competing reactions, allowing to discriminate between γ s originating from neutron induced fission and those from neutron capture reactions without the need for fission tagging or any additional detection system. In this article, the concept behind the CSD is explained in detail together with the necessary analysis to obtain the TAC's response to neutron capture and neutron induced fission. The discrimination between capture and fission contributions is shown for several neutron energies. A comparison between the 233U neutron capture and fission yield extraction with ENDF/B-VII v1. library data is also provided.

  8. An advanced data-acquisition system for wind energy projects

    SciTech Connect

    Simms, D.A. ); Cousineau, K.L. )

    1992-10-01

    NREL has subcontracted with Zond Systems, Inc. to develop an advanced data-acquisition system (ADAS) for wind energy projects. The ADAS can be used to simplify the process of making accurate measurements and analyzing. The system utilizes state-of-the-art electronics and telemetry to provide distributed multi-source, multi-channel data acquisition. Local stand-alone microprocessor-based data acquisition modules (DAMs) can be located near sources of measurement. These allow analog data values to be digitized close to the measurement source, thus eliminating the need for long data runs and slip rings. Signals from digital sensors and transducers can also be directly input to the local DAMS. A PC-based ground station is used to coordinate data transmission to and from all remote DAMS, display real-time values, archive data sets, and process and analyze results. The system is capable of acquiring synchronized time-series data from sensors and transducers under a variety of test configurations in an operational wind-park environment. Data acquisition needs of the wind industry differ significantly from those of most other technologies. Most conventional system designs do not handle data coming from multiple distributed sources, nor do they provide telemetry or the ability to mesh multiple incoming digital data streams. This paper describes the capabilities of the ADAS, and how its design and cost objectives are geared to meet anticipated US wind industry needs.

  9. Decreasing geothermal energy conversion costs with advanced materials

    SciTech Connect

    Kukacka, L.E.

    1988-03-01

    If the Geothermal Technology Division (GTD) is to meet its programmatic objectives in hydrothermal fluid production and energy conversion, it is essential that new materials of construction be available. Level III Program Objectives include (1) reducing the costs associated with lost circulation episodes by 30% by 1992, (2) reducing the costs of deep wells and directionally dried wells by 10% by 1992, (3) reducing well-cementing problems for typical hydrothermal wells by 20% by 1991, and (4) the development of a corrosion-resistant and low-fouling heat exchanger tube material costing no more than three times the cost of carbon steel tubes by 1991. The Brookhaven National Laboratory (BNL) materials program is focused on meeting these objectives. Currently, work is in progress on (1) high temperature chemical systems for lost circulation control, (2) advanced high temperature (300/sup 0/C), lightweight (approx. 1.1 g/cc), CO/sub 2/-resistant well cementing materials, (3) thermally conductive composites for heat exchanger tubing, and (4) ultra high temperature (600/sup 0/C) cements for magma wells. In addition, high temperature elastomer technology developed earlier in the program is being transferred for use in the Geothermal Drilling Organization programs on drill pipe protectors, rotating head seals, and blow-out preventors. Recent accomplishments and the current status of work in each subtask are summarized in the paper.

  10. Advanced Energy Retrofit Guide: Practical Ways to Improve Energy Performance, K-12 Schools (Book)

    SciTech Connect

    Not Available

    2013-12-01

    The U.S. Department of Energy developed the Advanced Energy Retrofit Guides (AERGs) to provide specific methodologies, information, and guidance to help energy managers and other stakeholders plan and execute energy efficiency improvements. Detailed technical discussion is fairly limited. Instead, we emphasize actionable information, practical methodologies, diverse case studies, and unbiased evaluations of the most promising retrofit energy efficiency measures for each building type. A series of AERGs is under development, addressing key segments of the commercial building stock. K-12 schools were selected as one of the highest priority building sectors, because schools affect the lives of most Americans. They also represent approximately 8% of the energy use and 10% of the floor area in commercial buildings nationwide. U.S. K-12 school districts spend more than $8 billion each year on energy - more than they spend on computers and textbooks combined. Most occupy older buildings that often have poor operational performance - more than 30% of schools were built before 1960. The average age of a school is about 42 years - which is nearly the expected serviceable lifespan of the building. K-12 schools offer unique opportunities for deep, cost-effective energy efficiency improvements, and this guide provides convenient and practical guidance for exploiting these opportunities in the context of public, private, and parochial schools.

  11. Clusterization in Ternary Fission

    NASA Astrophysics Data System (ADS)

    Kamanin, D. V.; Pyatkov, Y. V.

    This lecture notes are devoted to the new kind of ternary decay of low excited heavy nuclei called by us "collinear cluster tri-partition" (CCT) due to the features of the effect observed, namely, decay partners fly away almost collinearly and at least one of them has magic nucleon composition. At the early stage of our work the process of "true ternary fission" (fission of the nucleus into three fragments of comparable masses) was considered to be undiscovered for low excited heavy nuclei. Another possible prototype—three body cluster radioactivity—was also unknown. The most close to the CCT phenomenon, at least cinematically, stands so called "polar emission", but only very light ions (up to isotopes of Be) were observed so far.

  12. SHAPED FISSIONABLE METAL BODIES

    DOEpatents

    Wigner, E.P.; Williamson, R.R.; Young, G.J.

    1958-10-14

    A technique is presented for grooving the surface of fissionable fuel elements so that expansion can take place without damage to the interior structure of the fuel element. The fissionable body tends to develop internal stressing when it is heated internally by the operation of the nuclear reactor and at the same time is subjected to surface cooling by the circulating coolant. By producing a grooved or waffle-like surface texture, the annular lines of tension stress are disrupted at equally spaced intervals by the grooves, thereby relieving the tension stresses in the outer portions of the body while also facilitating the removal of accumulated heat from the interior portion of the fuel element.

  13. Fission Fragment Properties from a Microscopic Approach

    SciTech Connect

    Dubray, N.; Goutte, H.; Delaroche, J.-P.

    2008-04-17

    We calculate potential energy surfaces in the elongation-asymmetry plane, up to very large deformations, with the Hartree-Fock-Bogoliubov method and the Gogny nucleon-nucleon effective interaction DIS, for the {sup 226}Th and {sup 256,258,260}Fm fissioning systems. We then define a criterion based on the nuclear density, in order to discriminate between pre- and post-scission configurations. Using this criterion, many scission configurations are identified, and are used for the calculation of several fragment properties, like fragment deformations, deformation energies, energy partitioning, neutron binding energies at scission, charge polarization, total fragment kinetic energies and neutron multiplicities.

  14. [Fission product yields of 60 fissioning reactions]. Final report

    SciTech Connect

    Rider, B.F.

    1995-05-01

    In keeping with the statement of work, I have examined the fission product yields of 60 fissioning reactions. In co-authorship with the UTR (University Technical Representative) Talmadge R. England ``Evaluation and Compilation of Fission Product Yields 1993,`` LA-UR-94-3106(ENDF-349) October, (1994) was published. This is an evaluated set of fission product Yields for use in calculation of decay heat curves with improved accuracy has been prepared. These evaluated yields are based on all known experimental data through 1992. Unmeasured fission product yields are calculated from charge distribution, pairing effects, and isomeric state models developed at Los Alamos National Laboratory. The current evaluation has been distributed as the ENDF/B-VI fission product yield data set.

  15. Microscopic modeling of mass and charge distributions in the spontaneous fission of 240Pu

    NASA Astrophysics Data System (ADS)

    Sadhukhan, Jhilam; Nazarewicz, Witold; Schunck, Nicolas

    2016-01-01

    We propose a methodology to calculate microscopically the mass and charge distributions of spontaneous fission yields. We combine the multidimensional minimization of collective action for fission with stochastic Langevin dynamics to track the relevant fission paths from the ground-state configuration up to scission. The nuclear potential energy and collective inertia governing the tunneling motion are obtained with nuclear density functional theory in the collective space of shape deformations and pairing. We obtain a quantitative agreement with experimental data and find that both the charge and mass distributions in the spontaneous fission of 240Pu are sensitive both to the dissipation in collective motion and to adiabatic fission characteristics.

  16. Extended optical model for fission

    DOE PAGES

    Sin, M.; Capote, R.; Herman, M. W.; Trkov, A.

    2016-03-07

    A comprehensive formalism to calculate fission cross sections based on the extension of the optical model for fission is presented. It can be used for description of nuclear reactions on actinides featuring multi-humped fission barriers with partial absorption in the wells and direct transmission through discrete and continuum fission channels. The formalism describes the gross fluctuations observed in the fission probability due to vibrational resonances, and can be easily implemented in existing statistical reaction model codes. The extended optical model for fission is applied for neutron induced fission cross-section calculations on 234,235,238U and 239Pu targets. A triple-humped fission barrier ismore » used for 234,235U(n,f), while a double-humped fission barrier is used for 238U(n,f) and 239Pu(n,f) reactions as predicted by theoretical barrier calculations. The impact of partial damping of class-II/III states, and of direct transmission through discrete and continuum fission channels, is shown to be critical for a proper description of the measured fission cross sections for 234,235,238U(n,f) reactions. The 239Pu(n,f) reaction can be calculated in the complete damping approximation. Calculated cross sections for 235,238U(n,f) and 239Pu(n,f) reactions agree within 3% with the corresponding cross sections derived within the Neutron Standards least-squares fit of available experimental data. Lastly, the extended optical model for fission can be used for both theoretical fission studies and nuclear data evaluation.« less

  17. Achieving 50% Energy Savings in Office Buildings, Advanced Energy Design Guides: Office Buildings (Brochure)

    SciTech Connect

    Not Available

    2014-09-01

    This fact sheet summarizes recommendations for designing new office buildings that result in 50% less energy use than conventional designs meeting minimum code requirements. The recommendations are drawn from the Advanced Energy Design Guide for Small to Medium Office Buildings, an ASHRAE publication that provides comprehensive recommendations for designing low-energy-use office buildings with gross floor areas up to 100,000 ft2 (see sidebar). Designed as a stand-alone document, this fact sheet provides key principles and a set of prescriptive design recommendations appropriate for smaller office buildings with insufficient budgets to fully implement best practices for integrated design and optimized performance. The recommendations have undergone a thorough analysis and review process through ASHRAE, and have been deemed the best combination of measures to achieve 50% savings in the greatest number of office buildings.

  18. Achieving 50% Energy Savings in New Schools, Advanced Energy Design Guides: K-12 Schools (Brochure)

    SciTech Connect

    Not Available

    2014-09-01

    This fact sheet summarizes recommendations for designing elementary, middle, and high school buildings that will result in 50% less energy use than conventional new schools built to minimum code requirements. The recommendations are drawn from the Advanced Energy Design Guide for K-12 School Buildings, an ASHRAE publication that provides comprehensive recommendations for designing low-energy-use school buildings (see sidebar). Designed as a stand-alone document, this fact sheet provides key principles and a set of prescriptive design recommendations appropriate for smaller schools with insufficient budgets to fully implement best practices for integrated design and optimized performance. The recommendations have undergone a thorough analysis and review process through ASHRAE, and have been deemed the best combination of measures to achieve 50% savings in the greatest number of schools.

  19. Nuclear fission of neutron-deficient protactinium nuclides

    SciTech Connect

    Nishinaka, I.; Nagame, Y.; Tsukada, K.; Ikezoe, H.; Sueki, K.; Nakahara, H.; Tanikawa, M.; Ohtsuki, T.

    1997-08-01

    Fragment velocity, kinetic energy, mass yield, and element yield distributions in the fission of neutron-deficient Pa isotopes produced in the reactions of {sup 16}O and {sup 18}O on {sup 209}Bi have been measured at incident beam energies near and above the Coulomb barriers by the time-of-flight and radiochemical methods. An asymmetric mass-division component has been observed. Measured fission cross sections were compared with the results of statistical model calculations which take into account two fission barrier heights for symmetric and asymmetric yields. The fission barrier height deduced for the asymmetric fission is found slightly lower than that for the symmetric one. The difference between the two barrier heights in the fission of the present protactinium nuclides (N{approximately}135) is considerably smaller than that in the neutron-rich nuclide of {sup 233}Pa (N{approximately}142), indicating that the difference sensitively depends on the neutron number of the fissioning nuclide. {copyright} {ital 1997} {ital The American Physical Society}

  20. Fission properties of the 1. 5-s spontaneous fission activity produced in bombardmentof /sup 248/Cm with /sup 18/O

    SciTech Connect

    Hoffman, D.C.; Lee, D.; Ghiorso, A.; Nurmia, M.J.; Aleklett, K.; Leino, M.

    1981-08-01

    We have measured the mass and kinetic-energy distributions of fragments from the spontaneous fission of a 1.5-s activity produced in bombardments of /sup 248/Cm with 95-MeV /sup 18/O ions. Its spontaneous fission decay exhibits a very symmetric, narrow (full width at half maximum = 12 mass units) mass distribution, a very high total kinetic energy of 234 +- 2 MeV, and increasing total kinetic energy with increasingly symmetric mass division. Based on its half-life and the similarity of its fission properties to the unique fission properties so far only observed for /sup 258/Fm and /sup 259/Fm, the most likely assignment of this activity is to the known /sup 259/Fm. However, assignment to some as yet undiscovered neutron-rich heavy element isotope such as /sup 260/Md cannot be unequivocally excluded.