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1

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

Open Energy Info (EERE)

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

2

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

E-Print Network [OSTI]

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

Fritz, Harald

3

How many objects can you track?: Evidence for a resource-limited attentive tracking mechanism  

E-Print Network [OSTI]

How many objects can you track?: Evidence for a resource-limited attentive tracking mechanism can you track?: Evidence for a resource-limited attentive tracking mechanism. Journal of Vision, 7 model), or whether the limit on tracking is set by a resource that can be flexibly allocated to objects

Alvarez, George A.

4

Fission-track analysis of detrital zircon and J. I. Garver2  

E-Print Network [OSTI]

Geology Department Olin Building, Union College Schenectady, NY, 12308-3107, USA email: garverj with various isotopic methods having reasonable high concentrations of uranium and thorium (Fig. 1). Techniques depends on individual uranium content and cooling history of a zircon grain. Fission tracks in zircon have

Paris-Sud XI, Université de

5

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

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

6

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

SciTech Connect (OSTI)

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

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

2013-02-01T23:59:59.000Z

7

Evidence for Conical Intersection Dynamics Mediating Ultrafast Singlet Exciton Fission  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

8

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

E-Print Network [OSTI]

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

J. Marvin Herndon

2013-12-31T23:59:59.000Z

9

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

SciTech Connect (OSTI)

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

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

2007-02-28T23:59:59.000Z

10

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

E-Print Network [OSTI]

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

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

2005-06-27T23:59:59.000Z

11

Fission track evidence for widespread early to Middle miocene extension in  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublicIDAPowerPlantSitingConstruction.pdfNotify98.pdf Jump to:Siting.pdfFiskdale, Massachusetts: Energy

12

Does Tracking Shape the Intergenerational Transmission of Educational Attainment? Evidence from Switzerland  

E-Print Network [OSTI]

probit, Switzerland JEL-Classification: I21, J62, E24 Leading House in Economics of Vocational Education status on educational outcome of children across 31 participating coun- tries in the PISA program (OECDDoes Tracking Shape the Intergenerational Transmission of Educational Attainment? Evidence from

Paris-Sud XI, Université de

13

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

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted forHighlightsSeminarsSilicon spongeComputingCellFission April 3,

14

Skeletal P/Ca tracks upwelling in Gulf of Panama coral: Evidence for a new seawater phosphate proxy  

E-Print Network [OSTI]

Skeletal P/Ca tracks upwelling in Gulf of Panama´ coral: Evidence for a new seawater phosphate results that reveal annual cycles of P/Ca in a 4-year record from the scleractinian coral Pavona gigantea (mean P/Ca = 118 mmol mol?1 ). The P/Ca cycles track variations in past seawater phosphate concentration

Grottoli, Andréa G.

15

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

E-Print Network [OSTI]

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

Duflo, Esther

16

Benchmarking Nuclear Fission Theory  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

17

Benchmarking Nuclear Fission Theory  

E-Print Network [OSTI]

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

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

2015-02-20T23:59:59.000Z

18

Fission meter  

DOE Patents [OSTI]

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.

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

2012-04-10T23:59:59.000Z

19

E-Print Network 3.0 - alpha -particle fission Sample Search Results  

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

thermal history Summary: -feldspar ages (214 Ma) from the Jiazishan syenites. A titanite fission-track age of 166 8 Ma (closure... cooling and reheating event is indicated...

20

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

SciTech Connect (OSTI)

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

Lynn, J.E.

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

SciTech Connect (OSTI)

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

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

2014-09-01T23:59:59.000Z

22

Delayed-fission properties of neutron-deficient americium nuclei  

SciTech Connect (OSTI)

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.

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

1989-10-23T23:59:59.000Z

23

Fission gas detection system  

DOE Patents [OSTI]

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.

Colburn, Richard P. (Pasco, WA)

1985-01-01T23:59:59.000Z

24

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

E-Print Network [OSTI]

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

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

1997-04-18T23:59:59.000Z

25

Singlet fission photovoltaics  

E-Print Network [OSTI]

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

Lee, Jiye

2013-01-01T23:59:59.000Z

26

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

E-Print Network [OSTI]

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

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

2008-11-29T23:59:59.000Z

27

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

E-Print Network [OSTI]

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

De Cindio, Fiorella

28

Measuring the /sup 247/Cm fission cross section for neutron in the range 0. 02-3. 0 MeV  

SciTech Connect (OSTI)

The authors measured the energy dependence of the cross section for curium 247 fission caused by neutrons in the energy range 0.02-3.0 MeV using the transit time method and a nuclear explosion as an impulse neutron source. A polycarbonate film was used as a fission fragment detector. Tracks resulting from Curium 247 fission fragments were grouped on the basis of neutron energy into 24 intervals ranging from 0.02 to 3.16 MeV. The tracks of fission fragments from the uranium 235 reference isotope were similarly grouped. Results are graphed and tabulated.

Fomushkin, E.F.; Novoselov, G.F.; Vinogradov, Yu.I.; Gavrilov, V.V.; Zherebtsov, V.A.

1987-10-01T23:59:59.000Z

29

TRACKING SITE  

Energy Science and Technology Software Center (OSTI)

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

30

Method for correcting for isotope burn-in effects in fission neutron dosimeters  

DOE Patents [OSTI]

A method is described for correcting for effect of isotope burn-in in fission neutron dosimeters. Two quantities are measured in order to quantify the "burn-in" contribution, namely P.sub.Z',A', the amount of (Z', A') isotope that is burned-in, and F.sub.Z', A', the fissions per unit volume produced in the (Z', A') isotope. To measure P.sub.Z', A', two solid state track recorder fission deposits are prepared from the very same material that comprises the fission neutron dosimeter, and the mass and mass density are measured. One of these deposits is exposed along with the fission neutron dosimeter, whereas the second deposit is subsequently used for observation of background. P.sub.Z', A' is then determined by conducting a second irradiation, wherein both the irradiated and unirradiated fission deposits are used in solid state track recorder dosimeters for observation of the absolute number of fissions per unit volume. The difference between the latter determines P.sub.Z', A' since the thermal neutron cross section is known. F.sub.Z', A' is obtained by using a fission neutron dosimeter for this specific isotope, which is exposed along with the original threshold fission neutron dosimeter to experience the same neutron flux-time history at the same location. In order to determine the fissions per unit volume produced in the isotope (Z', A') as it ingrows during the irradiation, B.sub.Z', A', from these observations, the neutron field must generally be either time independent or a separable function of time t and neutron energy E.

Gold, Raymond (Richland, WA); McElroy, William N. (Richland, WA)

1988-01-01T23:59:59.000Z

31

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

SciTech Connect (OSTI)

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

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

2014-11-01T23:59:59.000Z

32

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

SciTech Connect (OSTI)

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

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

2007-08-28T23:59:59.000Z

33

Post-scission fission theory: Neutron emission in fission  

SciTech Connect (OSTI)

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

Madland, D.G.

1997-11-01T23:59:59.000Z

34

Fission throughout the periodic table  

SciTech Connect (OSTI)

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

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

1989-04-01T23:59:59.000Z

35

Measurement/Evaluation Techniques and Nuclear Data Associated with Fission of 239Pu by Fission Spectrum Neutrons  

SciTech Connect (OSTI)

This Panel was chartered to review and assess new evaluations of work on fission product data, as well as the evaluation process used by the two U.S. nuclear weapons physics laboratories. The work focuses on fission product yields resulting from fission spectrum neutrons incident on plutonium, and includes data from measurements that had not been previously published as well as new or revised fission product cumulative yield data, and related quantities such as Q values and R values. This report documents the Panel's assessment of the work presented by Los Alamos National Laboratory (LANL) and Lawrence Livermore National Laboratory (LLNL). Based on the work presented we have seven key observations: (1) Experiments conducted in the 1970s at LANL, some of which were performed in association with a larger, NIST-led, program, have recently been documented. A preliminary assessment of this work, which will be referred to in this document as ILRR-LANL, shows it to be technically sound. (2) LLNL has done a thorough, unbiased review and evaluation of the available literature and is in the process of incorporating the previously unavailable LANL data into its evaluation of key fission product yields. The results of the LLNL effort, which includes a preliminary evaluation of the ILRR-LANL data, have been documented. (3) LANL has also conducted an evaluation of fission product yields for fission spectrum neutrons on plutonium including a meta-analysis of benchmark data as part of a planned upgrade to the ENDF/B compilation. We found that the approach of using meta-analysis provides valuable additional insight for evaluating the sparse data sets involved in this assessment. (4) Both laboratories have provided convincing evidence for energy dependence in the fission product yield of {sup 147}Nd produced from the bombardment of {sup 239}Pu with fission spectrum neutrons over an incident neutron energy range of 0.2 to 1.9 MeV. (5) Consistent, complete, and explicit treatment of both systematic and statistical uncertainties, including correlations, are critical to the assessment of both the experimental measurements (due to variations between experimental techniques, irradiation conditions, calibration procedures, etc.), and the evaluation of those experiments to extract fundamental nuclear data. A clear example of the importance of uncertainty analysis is in the justification for energy-dependent {sup 147}Nd fission product yield, where the magnitude of the effect is comparable to the uncertainties of the individual fission product yield measurements. Both LANL and LLNL are committed to the inclusion of full uncertainty analysis in their evaluations. (6) The Panel reviewed in detail two methods for determining/evaluating fission product yields from which fission assessments can be made: the K factor method and high-resolution gamma spectroscopy (both described more fully in Sections 3 and 4). The panel concluded that fission product yields, and thus fission assessments, derived using either approach are equally valid, provided that the data were obtained from well understood, direct fission measurements and that the key underlying calibrations and/or data are valid for each technique. (7) The Panel found the process of peer review of the two complementary but independent methods to be an extremely useful exercise. Although work is still ongoing and the numbers presented to the Panel may change slightly, both groups are now in much better agreement on not just one, but four key fission product yields. The groups also have a better appreciation of the strengths and weaknesses of each other's methods.

Baisden, P; Bauge, E; Ferguson, J; Gilliam, D; Granier, T; Jeanloz, R; McMillan, C; Robertson, D; Thompson, P; Verdon, C; Wilkerson, C; Young, P

2010-03-16T23:59:59.000Z

36

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

SciTech Connect (OSTI)

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

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

2011-07-01T23:59:59.000Z

37

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

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

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

38

Investigations of neutron characteristics for salt blanket models; integral fission cross section measurements of neptunium, plutonium, americium and curium isotopes  

SciTech Connect (OSTI)

Neutron characteristics of salt blanket micromodels containing eutectic mixtures of sodium, zirconium and uranium sulphides were measured on FKBN-2M, BIGR and MAKET installations. The effective fission cross sections of neptunium, plutonium, americium and curium isotopes were measured on the neutron spectra formed by micromodels. KEYWORDS: transmutation, minor actinides, fluoride salts, micromodel, critical assembly, neutron spectrum, multiplication coefficient, fission, effective cross section, nuclear track detector, nuclear data library

Novoselov, G. F.; Gavrilov, V. V.; Kuvshinov, M. (Mikhail); Bogdanov, V. M. (Vladimir Mikha?lovich); Maslov, Georgi? Vladimirovich,; Vyachin, V. (Vladimir); Mashnik, S. G. (Stepan G.); Gorelov, V. I. (Vladimir Ivanovich); Fomushkin, E. F.

2001-01-01T23:59:59.000Z

39

Neutron Emission in Fission And Quasi-Fission of Hs  

SciTech Connect (OSTI)

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.

Itkis, I. M.; Itkis, M. G.; Knyazheva, G. N.; Kozulin, E. M.; Krupa, L. [Flerov Laboratory of Nuclear Reactions, JINR, Dubna (Russian Federation); Hanappe, F. [Universite Libre de Bruxelles, Belgique (Belgium); Dorvaux, O.; Stuttge, L. [Institut de Recherches Subatomiques, Strasbourg (France)

2010-04-30T23:59:59.000Z

40

Fission product solvent extraction  

SciTech Connect (OSTI)

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

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

1998-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Process for treating fission waste. [Patent application  

DOE Patents [OSTI]

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.

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

1981-11-17T23:59:59.000Z

42

Neutronics for critical fission reactors and subcritical fission in hybrids  

SciTech Connect (OSTI)

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

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

2012-06-19T23:59:59.000Z

43

Space Fission System Test Effectiveness  

SciTech Connect (OSTI)

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

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

2004-02-04T23:59:59.000Z

44

Microscopic Description of Nuclear Fission Dynamics  

E-Print Network [OSTI]

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

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

2010-03-22T23:59:59.000Z

45

Fusion-Fission Hybrid for Fissile Fuel Production without Processing  

SciTech Connect (OSTI)

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

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

2012-01-02T23:59:59.000Z

46

Status of fission yield evaluations  

SciTech Connect (OSTI)

Very few yield compilations are also evaluations, and very few contain an extensive global library of measured data and extensive models for unmeasured data. The earlier U.K. evaluations and US evaluations were comparable up to the retirements of the primary evaluators. Only the effort in the US has been continued and expanded. The previous U.K. evaluations have been published. In this paper we summarize the current status of the US evaluation, philosophy, and various integral yield tests for 34 fissioning nuclides at one or more neutron incident energies and/or for spontaneous fission. Currently there are 50 yield sets and for each we have independent and cumulative yields and uncertainties for approximately 1100 fission products. When finalized, the recommended data will become part of the next version of the US Evaluated Nuclear Data File (ENDF/B-VI). The complete set of data, including the basic input of measured yields, will be issued as a sequel to the General Electric evaluation reports (better known by the authors' names: Rider - or earlier - Meek and Rider). 16 references.

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

1983-01-01T23:59:59.000Z

47

MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.  

SciTech Connect (OSTI)

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.

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

2005-05-01T23:59:59.000Z

48

Fission barriers and half-lives  

SciTech Connect (OSTI)

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

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

1989-01-01T23:59:59.000Z

49

Fission fragment excited laser system  

DOE Patents [OSTI]

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

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

1976-01-01T23:59:59.000Z

50

Options for Affordable Fission Surface Power Systems  

SciTech Connect (OSTI)

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

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

2006-07-01T23:59:59.000Z

51

Theoretical Description of the Fission Process  

SciTech Connect (OSTI)

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 nations nuclear stockpile and nuclear reactors. The deployment of a fleet of safe and efficient advanced reactors, which will also minimize radiotoxic waste and be proliferation-resistant, is a goal for the advanced nuclear fuel cycles program. While in the past the design, construction, and operation of reactors were supported through empirical trials, this new phase in nuclear energy production is expected to heavily rely on advanced modeling and simulation capabilities.

Witold Nazarewicz

2009-10-25T23:59:59.000Z

52

Event-by-Event Fission with FREYA  

SciTech Connect (OSTI)

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

Randrup, J; Vogt, R

2010-11-09T23:59:59.000Z

53

Improved Calculation of Thermal Fission Energy  

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

54

Superfluid dynamics of 258Fm fission  

E-Print Network [OSTI]

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

Guillaume Scamps; Cdric Simenel; Denis Lacroix

2015-01-15T23:59:59.000Z

55

Superfluid dynamics of 258Fm fission  

E-Print Network [OSTI]

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

Scamps, Guillaume; Lacroix, Denis

2015-01-01T23:59:59.000Z

56

Fission-energy release for 16 fissioning nuclides. Final report  

SciTech Connect (OSTI)

Results are presented of a least-squares evaluation of the components of energy release per fission in /sup 232/Th, /sup 233/U, /sup 235/U, /sup 238/U, /sup 239/Pu, and /sup 241/Pu. For completeness, older (1978) results based on systematics are presented for these and ten other isotopes of interest. There have been recent indications that the delayed energy components may be somewhat higher than those used previously, but the LSQ results do not seem to change significantly when modest (approx. 1 MeV) increases in the total delayed energy are included in the inputs. Additional measurements of most of the energy components are still needed to resolve remaining discrepancies.

Sher, R.

1981-03-01T23:59:59.000Z

57

Cycle Track Lessons Learned  

E-Print Network [OSTI]

Cycle Track Lessons Learned #12;Presentation Overview · Bicycling trends · Cycle track lessons learned · What is a "Cycle track"? · Essential design elements of cycle tracks Separation Width Crossing driveways & low-volume streets Signalized intersections #12;Trend in kilometers cycled per year

Bertini, Robert L.

58

Track 2: Worker Engagement  

Broader source: Energy.gov [DOE]

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

59

Track 3: Exposure Hazards  

Broader source: Energy.gov [DOE]

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

60

Track 9: Quality Assurance  

Broader source: Energy.gov [DOE]

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

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Latent ion tracks in amorphous silicon  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

62

Nuclear Thermal Rockets: The Physics of the Fission Reactor  

E-Print Network [OSTI]

Nuclear Thermal Rockets: The Physics of the Fission Reactor Shane D. Ross Control and Dynamical heats up when it passes through a nuclear reactor, where controlled fission of some fissionable material, with the nuclear fission reactor as a heat source [Lawrence, Witter, and Humble, 1992]. it works essentially

Ross, Shane

63

Future challenges for nuclear data research in fission (u)  

SciTech Connect (OSTI)

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

Chadwick, Mark B [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

64

Reactor power history from fission product signatures  

E-Print Network [OSTI]

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

Sweeney, David J.

2009-05-15T23:59:59.000Z

65

Nuclear fission as resonance-mediated conductance  

E-Print Network [OSTI]

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

G. F. Bertsch

2014-12-18T23:59:59.000Z

66

Influence of a surfactant on single ion track etching: Preparing and manipulating cylindrical micro wires  

E-Print Network [OSTI]

Influence of a surfactant on single ion track etching: Preparing and manipulating cylindrical micro.1 vol.%) the formation of cylindrical channels is favoured. The shape of these channels (length P 26 lm energetic heavy ion or fission fragment to supply the energy necessary for rendering a cylindrical volume

Yu, K.N.

67

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

E-Print Network [OSTI]

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

De Cindio, Fiorella

68

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

SciTech Connect (OSTI)

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

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

2012-09-06T23:59:59.000Z

69

Our 50-year odyssey with fission: Summary  

SciTech Connect (OSTI)

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.

Nix, J.R.

1989-01-01T23:59:59.000Z

70

Modeling Fission Product Sorption in Graphite Structures  

SciTech Connect (OSTI)

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

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

2013-04-08T23:59:59.000Z

71

Fission reactor experiments for solid breeder blankets  

SciTech Connect (OSTI)

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

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

1986-11-01T23:59:59.000Z

72

Theoretical descriptions of neutron emission in fission  

SciTech Connect (OSTI)

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

Madland, D.G.

1990-01-01T23:59:59.000Z

73

E-Print Network 3.0 - asymmetric nucleon-induced fission Sample...  

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

POLONICA B No 4 BIMODAL FISSION Summary: modes allows to describe observed asymmetric fis- sion of 256 Fm, as well as bimodal fission of 258 Fm... fission, respectively....

74

E-Print Network 3.0 - asymmetrical fission type Sample Search...  

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

POLONICA B No 4 BIMODAL FISSION Summary: modes allows to describe observed asymmetric fis- sion of 256 Fm, as well as bimodal fission of 258 Fm... fission, respectively....

75

Solar tracking apparatus  

DOE Patents [OSTI]

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

Hammons, Burrell E. (Albuquerque, NM)

1980-01-01T23:59:59.000Z

76

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

E-Print Network [OSTI]

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

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

2006-06-06T23:59:59.000Z

77

Energy partition in low energy fission  

E-Print Network [OSTI]

The intrinsic excitation energy of fission fragments is dynamically evaluated in terms of the time dependent pairing equations. These equations are corroborated with two conditions. One of them fixes the number of particles and the another separates the pairing active spaces associated to the two fragments in the vicinity of the scission configuration. The fission path is obtained in the frame of the macroscopic-microscopic model. The single particle level schemes are obtained within the two center Woods-Saxon shell model. It is shown that the available intrinsic dissipated energy is not shared proportionally to the masses of the two fission fragments. If the heavy fragment possesses nucleon numbers close to the magic ones, the accumulated intrinsic excitation energy is lower than that of the light fragment.

M. Mirea

2011-02-14T23:59:59.000Z

78

achieve comparable fission: Topics by E-print Network  

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

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

79

accompanied ternary fission: Topics by E-print Network  

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

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

80

active inspection fission: Topics by E-print Network  

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

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

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Italian hybrid and fission reactors scenario analysis  

SciTech Connect (OSTI)

Italy is a country where a long tradition of studies both in the fission and fusion field is consolidated; nevertheless a strong public opinion concerned with the destination of the Spent Nuclear Fuel hinders the development of nuclear power. The possibility to a severe reduction of the NSF mass generated from a fleet of nuclear reactors employing an hypothetical fusionfission hybrid reactor has been investigated in the Italian framework. The possibility to produce nuclear fuel for the fission nuclear reactors with the hybrid reactor was analyzed too.

Ciotti, M.; Manzano, J.; Sepielli, M. [ENEA CR Frascati, Via Enrico Fermi, 45, 00044, Frascati, Roma (Italy); ENEA CR casaccia, Via Anguillarese, 301, 00123, Santa Maria di Galeria, Roma (Italy)

2012-06-19T23:59:59.000Z

82

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

SciTech Connect (OSTI)

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

Bond, P.D.

1985-08-01T23:59:59.000Z

83

Muon Tracking to Detect Special Nuclear Materials  

SciTech Connect (OSTI)

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

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

2013-03-18T23:59:59.000Z

84

Half-life for spontaneous fission of /sup 243/Cm  

SciTech Connect (OSTI)

A method is proposed for measuring the half-life for spontaneous fission of curium 243. Isotope separation and purification techniques are described and the isotope ratio of the purified target is given. The efficiency of fission fragment detection for solid state mica detectors was measured with a curium 244 standard. Results for the rate of spontaneous fission are tabulated.

Polynov, V.N.; Druzhinin, A.A.; Korochkin, A.M.; Nikitin, E.A.; Bochkarev, V.A.; Vyachin, V.N.; Lapin, V.G.; Maksimov, M.Yu.

1987-10-01T23:59:59.000Z

85

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

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

86

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

SciTech Connect (OSTI)

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

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

2009-03-04T23:59:59.000Z

87

Transfer-induced fission of superheavy nuclei  

SciTech Connect (OSTI)

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.

Adamian, G. G. [Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Institute of Nuclear Physics, Tashkent, UZ-702132 Uzbekistan (Uzbekistan); Antonenko, N. V.; Zubov, A. S. [Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Sargsyan, V. V. [Joint Institute for Nuclear Research, RU-141980 Dubna (Russian Federation); Yerevan State University, Yerevan (Armenia); Scheid, W. [Institut fuer Theoretische Physik der Justus-Liebig-Universitaet, D-35392 Giessen (Germany)

2010-07-15T23:59:59.000Z

88

Liquid uranium alloy-helium fission reactor  

DOE Patents [OSTI]

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

Minkov, V.

1984-06-13T23:59:59.000Z

89

Liquid uranium alloy-helium fission reactor  

DOE Patents [OSTI]

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

Minkov, Vladimir (Skokie, IL)

1986-01-01T23:59:59.000Z

90

Density Functional Theory Approach to Nuclear Fission  

E-Print Network [OSTI]

The Skyrme nuclear energy density functional theory (DFT) is used to model neutron-induced fission in actinides. This paper focuses on the numerical implementation of the theory. In particular, it reports recent advances in DFT code development on leadership class computers, and presents a detailed analysis of the numerical accuracy of DFT solvers for near-scission calculations.

N. Schunck

2013-01-20T23:59:59.000Z

91

FISSION REACTORS KEYWORDS: core-barrel vibra-  

E-Print Network [OSTI]

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

Demazière, Christophe

92

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

SciTech Connect (OSTI)

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

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

2005-05-24T23:59:59.000Z

93

Fission Yield Measurements by Inductively Coupled Plasma Mass-Spectrometry  

SciTech Connect (OSTI)

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

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

2009-11-01T23:59:59.000Z

94

Large scale tracking algorithms.  

SciTech Connect (OSTI)

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

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

2015-01-01T23:59:59.000Z

95

Conservation of Isospin in Neutron-Rich Fission Fragments  

E-Print Network [OSTI]

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

Ashok Kumar Jain; Deepika Choudhury; Bhoomika Maheshwari

2014-08-11T23:59:59.000Z

96

Fusion-fission energy systems evaluation  

SciTech Connect (OSTI)

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.

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

1980-01-01T23:59:59.000Z

97

Fission-product-decay characteristics. Master's thesis  

SciTech Connect (OSTI)

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

Millage, K.K.

1989-03-01T23:59:59.000Z

98

Time dependent particle emission from fission products  

SciTech Connect (OSTI)

Decay heating following nuclear fission is an important factor in the design of nuclear facilities; impacting a variety of aspects ranging from cooling requirements to shielding design. Calculations of decay heat, often assumed to be a simple product of activity and average decay product energy, are complicated by the so called 'pandemonium effect'. Elucidated in the 1970's this complication arises from beta-decays feeding high-energy nuclear levels; redistributing the available energy between betas and gammas. Increased interest in improving the theoretical predictions of decay probabilities has been, in part, motivated by the recent experimental effort utilizing the Total Absorption Gamma-ray Spectrometer (TAGS) to determine individual beta-decay transition probabilities to individual nuclear levels. Accurate predictions of decay heating require a detailed understanding of these transition probabilities, accurate representation of particle decays as well as reliable predictions of temporal inventories from fissioning systems. We will discuss a recent LANL effort to provide a time dependent study of particle emission from fission products through a combination of Quasiparticle Random Phase Approximation (QRPA) predictions of beta-decay probabilities, statistical Hauser-Feshbach techniques to obtain particle and gamma-ray emissions in statistical Hauser-Feshbach and the nuclear inventory code, CINDER.

Holloway, Shannon T [Los Alamos National Laboratory; Kawano, Toshihiko [Los Alamos National Laboratory; Moller, Peter [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

99

Energy Tracking Software Platform  

SciTech Connect (OSTI)

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

Ryan Davis; Nathan Bird; Rebecca Birx; Hal Knowles

2011-04-04T23:59:59.000Z

100

Exotic fission properties of highly neutron-rich Uranium isotopes  

E-Print Network [OSTI]

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

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

2007-03-05T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Track 10: Feedback and Improvement  

Broader source: Energy.gov [DOE]

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

102

Fission product yields for fast-neutron fission of /sup 243,244,246,248/Cm  

SciTech Connect (OSTI)

Recent measurements of relative yields for /sup 95/Zr, /sup 125/Sb, /sup 137/Cs, /sup 141/Ce, /sup 144/Ce, and /sup 155/Eu for fast-neutron fission of samples enriched in the actinides /sup 243,244,246,248/Cm have been combined with a simple mass-distribution model to predict complete mass distributions for fast-neutron fission of each of these four curium actinides. Complete descriptions of the data analysis and of the model and its application and limitations are given.

Dickens, J.K.

1987-05-01T23:59:59.000Z

103

ATLAS Tracking Event Data Model  

E-Print Network [OSTI]

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

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

2006-01-01T23:59:59.000Z

104

Proton induced fission of 181-Ta at relativistic energies  

E-Print Network [OSTI]

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

Y. Ayyad; J. Benlliure; E. Casarejos; H. lvarez-Pol; A. Bacquias; A. Boudard; M. Caamao; T. Enqvist; V. Fhr; A. Keli?-Heil; K. Kezzar; S. Leray; C. Paradela; D. Prez-Loureiro; R. Pleska?; D. Tarro

2012-03-07T23:59:59.000Z

105

Spontaneous fission half-lives for ground state nuclides  

SciTech Connect (OSTI)

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

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

1993-08-01T23:59:59.000Z

106

Time dependence of delayed neutron emission for fissionable isotope identification  

SciTech Connect (OSTI)

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

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

2005-06-20T23:59:59.000Z

107

SciTech Connect: The Microscopic Theory of Fission  

Office of Scientific and Technical Information (OSTI)

CA Sponsoring Org: USDOE Country of Publication: United States Language: English Subject: 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; FISSION; KINETICS; NEUTRONS; SPECTROSCOPY...

108

September 2013 Most Viewed Documents for Fission And Nuclear...  

Office of Scientific and Technical Information (OSTI)

September 2013 Most Viewed Documents for Fission And Nuclear Technologies Science Subject Feed Estimation of gas leak rates through very small orifices and channels. From sealed...

109

January 2013 Most Viewed Documents for Fission And Nuclear Technologie...  

Office of Scientific and Technical Information (OSTI)

January 2013 Most Viewed Documents for Fission And Nuclear Technologies Laboratory studies of shearleach processing of zircaloy clad metallic uranium reactor fuel Swanson, J.L.;...

110

Uncertainties analysis of fission fraction for reactor antineutrino experiments  

E-Print Network [OSTI]

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

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

2015-03-17T23:59:59.000Z

111

Exciton Dynamics and Structural Investigations of Singlet Fission...  

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

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

112

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

E-Print Network [OSTI]

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

Mahata, K; Kapoor, S S

2015-01-01T23:59:59.000Z

113

Excitation energy dependence of fission in the mercury region  

E-Print Network [OSTI]

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

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

2014-06-26T23:59:59.000Z

114

Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE  

SciTech Connect (OSTI)

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.

Jandel, Marian [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

115

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

SciTech Connect (OSTI)

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.

Not Available

1980-03-01T23:59:59.000Z

116

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

SciTech Connect (OSTI)

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

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

1994-11-01T23:59:59.000Z

117

Electroplating method for producing ultralow-mass fissionable deposits  

DOE Patents [OSTI]

A method for producing ultralow-mass fissionable deposits for nuclear reactor dosimetry is described, including the steps of holding a radioactive parent until the radioactive parent reaches secular equilibrium with a daughter isotope, chemically separating the daughter from the parent, electroplating the daughter on a suitable substrate, and holding the electroplated daughter until the daughter decays to the fissionable deposit.

Ruddy, Francis H. (Monroeville, PA)

1989-01-01T23:59:59.000Z

118

Chemical factors affecting fission product transport in severe LMFBR accidents  

SciTech Connect (OSTI)

This study was performed as a part of a larger evaluation effort on LMFBR accident, source-term estimation. Purpose was to provide basic chemical information regarding fission product, sodium coolant, and structural material interactions required to perform estimation of fission product transport under LMFBR accident conditions. Emphasis was placed on conditions within the reactor vessel; containment vessel conditions are discussed only briefly.

Wichner, R.P.; Jolley, R.L.; Gat, U.; Rodgers, B.R.

1984-10-01T23:59:59.000Z

119

Improved zircon fission-track annealing model based on reevaluation of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation ProposedUsingFun withconfinementEtching.348 270 300 219 255Retrievals

120

Pollution Prevention Tracking and Reporting System | Department...  

Energy Savers [EERE]

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

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Circle Track Magazine Project GREEN: New Smyrna Track Testing...  

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

Grassroots Renewable Fuels Revolution Presenters Forrest Jehlik -Argonne National Laboratory Contributors Danny Bocci (Argonne National Laboratory). Bob Bolles (Circle Track...

122

Ceramic Hosts for Fission Products Immobilization  

SciTech Connect (OSTI)

Natural spinel, perovskite and zirconolite rank among the most leach resistant of mineral forms. They also have a strong affinity for a large number of other elements and including actinides. Specimens of natural perovskite and zirconolite were radioisotope dated and found to have survived at least 2 billion years of natural process while still remain their loading of uranium and thorium . Developers of the Synroc waste form recognized and exploited the capability of these minerals to securely immobilize TRU elements in high-level waste . However, the Synroc process requires a relatively uniform input and hot pressing equipment to produce the waste form. It is desirable to develop alternative approaches to fabricate these durable waste forms to immobilize the radioactive elements. One approach is using a high temperature process to synthesize these mineral host phases to incorporate the fission products in their crystalline structures. These mineral assemblages with immobilized fission products are then isolated in a durable high temperature glass for periods measured on a geologic time scale. This is a long term research concept and will begin with the laboratory synthesis of the pure spinel (MgAl2O4), perovskite (CaTiO3) and zirconolite (CaZrTi2O7) from their constituent oxides. High temperature furnace and/or thermal plasma will be used for the synthesis of these ceramic host phases. Nonradioactive strontium oxide will be doped into these ceramic phases to investigate the development of substitutional phases such as Mg1-xSrxAl2O4, Ca1-xSrxTiO3 and Ca1-xSrxZrTi2O7. X-ray diffraction will be used to establish the crystalline structures of the pure ceramic hosts and the substitution phases. Scanning electron microscopy and energy dispersive X-ray analysis (SEM-EDX) will be performed for product morphology and fission product surrogates distribution in the crystalline hosts. The range of strontium doping is planned to reach the full substitution of the divalent metal ions, Mg and Ca, in the ceramic host phases. The immobilization of rear earth (lanthanide series) fission products in these ceramic host phases will also be studied this year. Cerium oxide is chosen to represent the rear earth fission product for substitution studies in spinel, perovskite and zirconolite ceramic hosts. Cerium has +3 and +4 oxidation states and it can replace some of the trivalent or tetravalent host ions to produce the substitution ceramics such as MgAl2-xCexO4, CaTi1-xCexO3, CaZr1-xCexTi2O7 and CaZrTi2-xCexO7. X-ray diffraction analysis will be used to compare the crystalline structures of the pure ceramic hosts and the substitution phases. SEM-EDX analysis will be used to study the Ce distribution in the ceramic host phases. The range of cerium doping is planned to reach the full substitution of the trivalent or tetravalent ions, Al, Ti and Zr, in the ceramic host phases.

Peter C Kong

2010-07-01T23:59:59.000Z

123

Fission matrix capability for MCNP, Part II - Applications  

SciTech Connect (OSTI)

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

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

2013-07-01T23:59:59.000Z

124

Multiple-Coincidence Active Neutron Interrogation of Fissionable Materials  

SciTech Connect (OSTI)

Using a beam of tagged 14.1 MeV neutrons to probe for the presence of fissionable materials, we have measured n-?-? coincidences from depleted uranium (DU). The multiple coincidence rate is substantially above that measured from lead, tungsten, and iron. The presence of coincidences involving delayed gammas in the DU time spectra provides a signature for fissionable materials that is distinct from non-fissionable ones. In addition, the information from the tagged neutron involved in the coincidence gives the position of the fissionable material in all three dimensions. The result is an imaging probe for fissionable materials that is more compact and that produces much less radiation than other solutions.

J.P. Hurley, R.P. Keegan, J.R. Tinsley, R. Trainham, and S.C. Wilde

2008-08-06T23:59:59.000Z

125

Improved Fission Neutron Data Base for Active Interrogation of Actinides  

SciTech Connect (OSTI)

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).

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

2013-11-06T23:59:59.000Z

126

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

E-Print Network [OSTI]

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

Chaudhuri, G; Chaudhuri, Gargi; Pal, Santanu

2002-01-01T23:59:59.000Z

127

Control system for a small fission reactor  

DOE Patents [OSTI]

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

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

1985-02-08T23:59:59.000Z

128

Detecting fission from special nuclear material sources  

DOE Patents [OSTI]

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

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

2012-06-05T23:59:59.000Z

129

A New Method of Prompt Fission Neutron Energy Spectrum Unfolding  

SciTech Connect (OSTI)

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.

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

2010-11-25T23:59:59.000Z

130

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

SciTech Connect (OSTI)

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.

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

1986-01-01T23:59:59.000Z

131

Compilation of fission product yields Vallecitos Nuclear Center  

SciTech Connect (OSTI)

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.

Rider, B.F.

1980-01-01T23:59:59.000Z

132

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

E-Print Network [OSTI]

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

133

Active Fusion and Fission Processes on a Fluid Membrane  

E-Print Network [OSTI]

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

Madan Rao; Sarasij R C

2001-02-26T23:59:59.000Z

134

Cross section for the subbarrier fission of {sup 244}Cm  

SciTech Connect (OSTI)

The cross section for {sup 244}Cm fission induced by neutrons of energy in the range between 0.07 eV and 20 keV was measured by using the lead slowing-down spectrometer (LSDS-100) of the Institute for Nuclear Research (Russian Academy of Sciences, Moscow). The parameters of the resonance areas were determined for the lowest eight s-wave neutron resonances, and the respective fission widths were evaluated. Also, the parameters of the intermediate structure in the cross section for the subbarrier fission of {sup 244}Cm nuclei were evaluated. The results were compared with available data and recommendations based on evaluations.

Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Samylin, B. F.; Svirin, M. I.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S., E-mail: shorin@ippe.r [Institute of Physics and Power Engineering (Russian Federation)

2010-09-15T23:59:59.000Z

135

Sensitivity analysis of the fission gas behavior model in BISON.  

SciTech Connect (OSTI)

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

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

2013-05-01T23:59:59.000Z

136

Discovery of a new mode of nuclear fission  

SciTech Connect (OSTI)

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.

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.

1986-01-01T23:59:59.000Z

137

Experimental Progress Report--Modernizing the Fission Basis  

SciTech Connect (OSTI)

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

Macri, R A

2012-02-17T23:59:59.000Z

138

Actinide Neutron-Induced Fission Cross Section Measurements At LANSCE  

SciTech Connect (OSTI)

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. Parallel-plate ionization chambers 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 existing evaluations and previous data.

Tovesson, F.; Laptev, A. B. [Los Alamos National Laboratory, Los Alamos NM 87545 (United States); Hill, T. S. [Idaho National Laboratory, Idaho Falls ID 83415 (United States)

2011-06-01T23:59:59.000Z

139

Forensic Tracking and Surveillance Algorithms for Homogeneous and Heterogeneous Settings  

E-Print Network [OSTI]

Forensic Tracking and Surveillance Algorithms for Homogeneous and Heterogeneous Settings Submitted-Kuwari) Date: #12;"I cannot succeed except through God" #12;Abstract Digital forensics is an emerging field. Traditionally, digital forensics has been confined to the extraction of digital evidence from electronic devices

Sheldon, Nathan D.

140

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

SciTech Connect (OSTI)

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

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

2011-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Vertexing and Tracking Software at LHCb  

E-Print Network [OSTI]

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

Bowen, Espen Eie

2015-01-01T23:59:59.000Z

142

Fusion-fission reactions with modified Woods-Saxon potential  

E-Print Network [OSTI]

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

Ning Wang; Kai Zhao; Werner Scheid; Xizhen Wu

2007-12-15T23:59:59.000Z

143

Half life for spontaneous fission of curium-245  

SciTech Connect (OSTI)

A sample of curium-245 of extremely high enrichment was obtained with an electromagnetic separator. The half-life for spontaneous fission was determined by measuring the rate of alpha decay. (AIP)

Druzhinin, A.A.; Polynov, V.N.; Vesnovskii, S.P.; Korochkin, A.M.; Lbov, A.A.; Nikitin, E.A.

1985-02-01T23:59:59.000Z

144

Spontaneous fission half-lives for ground state nuclides  

SciTech Connect (OSTI)

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

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

1991-01-01T23:59:59.000Z

145

Total Prompt Energy Release in the Neutron-Induced Fission  

E-Print Network [OSTI]

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

D. G. Madland

2006-01-01T23:59:59.000Z

146

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

Office of Scientific and Technical Information (OSTI)

June 2014 Most Viewed Documents for Fission And Nuclear Technologies Behavior of spent nuclear fuel in water pool storage Johnson, A.B. Jr. (1977) 78 Estimation of gas leak rates...

147

July 2013 Most Viewed Documents for Fission And Nuclear Technologies...  

Office of Scientific and Technical Information (OSTI)

July 2013 Most Viewed Documents for Fission And Nuclear Technologies Science Subject Feed Estimation of gas leak rates through very small orifices and channels. From sealed PuO...

148

Singlet exciton fission : applications to solar energy harvesting  

E-Print Network [OSTI]

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

Thompson, Nicholas John

2014-01-01T23:59:59.000Z

149

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

SciTech Connect (OSTI)

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

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

2010-08-15T23:59:59.000Z

150

Cross section for fast neutron induced /sup 243/Cm fission  

SciTech Connect (OSTI)

The authors discuss a method for measuring the cross section of the fission of curium 243 which either eliminates or corrects for the interference arising from sister isotopes or from the half-life spontaneous fission of this isotope. Soda-lime glass was used as the detector material and uranium 235 as the calibration standard. The irradiation facility is described. Error estimates are given.

Fomushkin, E.F.; Novoselov, G.F.; Vinogradov, Yu.I.; Vyachin, V.N.; Gavrilov, V.V.; Koshelev, A.S.; Polynov, V.N.; Surin, V.M.; Shvetsov, A.M.

1987-10-01T23:59:59.000Z

151

Present Status of Fission Research Based on TDDFT  

E-Print Network [OSTI]

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

Yoritaka Iwata

2015-01-28T23:59:59.000Z

152

Evaluation and compilation of fission product yields 1993  

SciTech Connect (OSTI)

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

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

1995-12-31T23:59:59.000Z

153

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

SciTech Connect (OSTI)

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

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

2000-04-01T23:59:59.000Z

154

Method to calibrate fission chambers in Campbelling mode  

SciTech Connect (OSTI)

Fission chambers are neutron detectors which are widely used to instrument experimental reactors such as material testing reactors or zero power reactors. In the presence of a high level mixed gamma and neutron flux, fission chambers can be operated in Campbelling mode (also known as 'fluctuation mode' or 'mean square voltage mode') to provide reliable and precise neutron related measurements. Fission chamber calibration in Campbelling mode (in terms of neutron flux) is usually done empirically using a calibrated reference detector. A major drawback of this method is that calibration measurements have to be performed in a neutron environment very similar to the one in which the calibrated detector will be used afterwards. What we propose here is a different approach based on characterizing the fission chamber response in terms of fission rate. This way, the detector calibration coefficient is independent from the neutron spectrum and can be determined prior to the experiment. The fissile deposit response to the neutron spectrum can then be assessed independently by other means (experimental or numerical). In this paper, the response of CEA made miniature fission chambers in Campbelling mode is studied. We use a theoretical model of the signal to calculate the calibration coefficient. Input parameters of the model come from statistical distribution of individual pulses. Supporting measurements have been made in the CEA Cadarache zero power reactor MINERVE. Results are compared to an empirical Campbelling mode calibration.

Benoit Geslot; Troy C. Unruh; Philippe Filliatre; Christian Jammes; Jacques Di Salvo; Stphane Braud; Jean-Franois Villard

2011-06-01T23:59:59.000Z

155

Symmetric and asymmetric fission modes in proton-induced fission at 660 MeV of {sup 238}U  

SciTech Connect (OSTI)

Fission product cross sections of intermediate-energy fission of {sup 238}U were used in order to construct the charge and mass yield distributions. Enriched target of {sup 238}U was irradiated by proton beam with energy 660 MeV for several hours at the LNP Phasotron, Joint Institute for Nuclear Research (JINR), Dubna, Russia. The charge distribution of the fission fragments was analyzed for calculation of isobaric cross sections. The mass yield curves were expanded into symmetric and asymmetric components according multimodal fission approach. The fissility values of actinides were calculated at given proton energy. The obtained results have been compared to the same data for targets {sup 237}Np and {sup 241}Am.

Balabekyan, A. R., E-mail: balabekyan@ysu.am; Karapetyan, G. S. [Yerevan State University (Armenia); Demekhina, N. A.; Adam, J. [JINR (Russian Federation); Katovsky, K. [Czech Technical University in Prague, Department of Nuclear Reactors (Czech Republic)

2010-11-15T23:59:59.000Z

156

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

SciTech Connect (OSTI)

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

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

2004-02-04T23:59:59.000Z

157

REC Tracking Systems Design Guide  

SciTech Connect (OSTI)

OAK-B135 The Design Guide is presented in three parts. Section II describes the need for REC tracking, the two principal tracking methods available, and, in simple terms, the operation of certificate-based systems. Section III presents the major issues in the design of certificate-based tracking systems and discusses the advantages and disadvantages of alternative solutions. Finally, Section IV offers design principles or recommendations for most of these issues.

Meredith Wingate

2004-02-03T23:59:59.000Z

158

Control system for a small fission reactor  

DOE Patents [OSTI]

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

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

1986-01-01T23:59:59.000Z

159

Ring fission of anthracene by a eukaryota  

SciTech Connect (OSTI)

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

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

1993-01-01T23:59:59.000Z

160

Ring fission of anthracene by a eukaryote  

SciTech Connect (OSTI)

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

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

1991-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

E-Print Network [OSTI]

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

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

2014-09-17T23:59:59.000Z

162

The Future of Energy from Nuclear Fission  

SciTech Connect (OSTI)

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

Kim, Son H.; Taiwo, Temitope

2013-04-13T23:59:59.000Z

163

BSTBacterial Source Tracking Conference Proceedings  

E-Print Network [OSTI]

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

164

Directional measurements for sources of fission neutrons  

SciTech Connect (OSTI)

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

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

1993-11-01T23:59:59.000Z

165

Neutron source capability assessment for cumulative fission yields measurements  

SciTech Connect (OSTI)

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

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

2011-04-06T23:59:59.000Z

166

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

E-Print Network [OSTI]

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

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

1998-04-30T23:59:59.000Z

167

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

SciTech Connect (OSTI)

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.

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

1980-10-01T23:59:59.000Z

168

CDC's National Environmental Public Health Tracking Network NEW MEXICO Keeping Track, Promoting Health  

E-Print Network [OSTI]

CS225774_D CDC's National Environmental Public Health Tracking Network NEW MEXICO Keeping Track Tracking Matters in New Mexico The New Mexico Tracking Program affords a better understanding of how diseases. The New Mexico Tracking Program has already begun using its state Tracking Network to monitor

169

Electron-capture delayed fission in {sup 246}Es  

SciTech Connect (OSTI)

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

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

1997-12-31T23:59:59.000Z

170

Initial Back-to-Back Fission Chamber Testing in ATRC  

SciTech Connect (OSTI)

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

Benjamin Chase; Troy Unruh; Joy Rempe

2014-06-01T23:59:59.000Z

171

Fission gas release restrictor for breached fuel rod  

DOE Patents [OSTI]

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

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

1986-01-01T23:59:59.000Z

172

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

E-Print Network [OSTI]

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

Kramer, Kevin James

2010-01-01T23:59:59.000Z

173

DOUBLE TRACKS Test Site interim corrective action plan  

SciTech Connect (OSTI)

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

NONE

1996-06-01T23:59:59.000Z

174

Midwest Renewable Energy Tracking System (Multiple States)  

Broader source: Energy.gov [DOE]

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

175

Increasing Scientific Productivity by Tracking Data  

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

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

176

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

Office of Environmental Management (EM)

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

177

Sputtering yield of Pu bombarded by fission Fragments from Cf  

SciTech Connect (OSTI)

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

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

2008-01-01T23:59:59.000Z

178

Neutron emission and fragment yield in high-energy fission  

SciTech Connect (OSTI)

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.

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

2013-07-15T23:59:59.000Z

179

Comparison of Fission Product Yields and Their Impact  

SciTech Connect (OSTI)

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

S. Harrison

2006-02-01T23:59:59.000Z

180

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

E-Print Network [OSTI]

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

Andrews, Nathan Christopher

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Comparison of various parametrizations of the double-humped fission barrier  

SciTech Connect (OSTI)

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

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

1991-07-01T23:59:59.000Z

182

E-Print Network 3.0 - actinide nuclei fission Sample Search Results  

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

fission with a large mass asymmetry within the self-consistent HFB theory. A new fis- sion valley... of this fission mode corresponds to the expected one in cluster...

183

E-Print Network 3.0 - asymmetric fission barriers Sample Search...  

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

POLONICA B No 4 BIMODAL FISSION Summary: modes allows to describe observed asymmetric fis- sion of 256 Fm, as well as bimodal fission of 258 Fm... - particle states for the...

184

E-Print Network 3.0 - actinides fission products Sample Search...  

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

fission with a large mass asymmetry within the self-consistent HFB theory. A new fis- sion valley... of this fission mode corresponds to the expected one in cluster...

185

Cooperative Modeling and Design History Tracking Using Design Tracking Matrix  

E-Print Network [OSTI]

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

Kim, Jonghyun

2010-10-12T23:59:59.000Z

186

Detecting a Nuclear Fission Reactor at the Center of the Earth  

E-Print Network [OSTI]

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

R. S. Raghavan

2002-08-24T23:59:59.000Z

187

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

SciTech Connect (OSTI)

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

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

1989-03-01T23:59:59.000Z

188

Abrasion resistant track shoe grouser  

DOE Patents [OSTI]

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

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

2013-04-23T23:59:59.000Z

189

Cross section for {sup 246}Cm subbarrier fission  

SciTech Connect (OSTI)

The cross section for {sup 246}Cm fission induced by neutrons of energy in the range 0.1 eV-20 keV was measured by the neutron lead slowing-down spectrometer (LSDS-100) of the Institute for Nuclear Research (INR, Russian Academy of Sciences, Moscow). The parameters of the resonance area and of the fission width were evaluated for several low-lying s-wave neutron resonances. The parameters of the intermediate structure in the cross section for the subbarrier fusion of {sup 246}Cm nuclei were found. The results obtained in this way were compared with available experimental data and with recommended evaluated data.

Alekseev, A. A.; Bergman, A. A.; Berlev, A. I.; Koptelov, E. A. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation); Samylin, B. F.; Trufanov, A. M.; Fursov, B. I.; Shorin, V. S., E-mail: shorin@ippe.r [Institute for Physics and Power Engineering (Russian Federation)

2010-10-15T23:59:59.000Z

190

Fission product release from irradiated LWR fuel under accident conditions  

SciTech Connect (OSTI)

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

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

1984-01-01T23:59:59.000Z

191

Singlet fission efficiency in tetracene-based organic solar cells  

SciTech Connect (OSTI)

Singlet exciton fission splits one singlet exciton into two triplet excitons. Using a joint analysis of photocurrent and fluorescence modulation under a magnetic field, we determine that the triplet yield within optimized tetracene organic photovoltaic devices is 153%??5% for a tetracene film thickness of 20?nm. The corresponding internal quantum efficiency is 127%??18%. These results are used to prove the effectiveness of a simplified triplet yield measurement that relies only on the magnetic field modulation of fluorescence. Despite its relatively slow rate of singlet fission, the measured triplet yields confirm that tetracene is presently the best candidate for use with silicon solar cells.

Wu, Tony C., E-mail: tonyw@mit.edu; Thompson, Nicholas J.; Congreve, Daniel N.; Hontz, Eric; Yost, Shane R.; Van Voorhis, Troy; Baldo, Marc A., E-mail: baldo@mit.edu [Energy Frontier Research Center for Excitonics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-05-12T23:59:59.000Z

192

Fission cross section calculations of actinides with EMPIRE code  

SciTech Connect (OSTI)

The cross sections of the neutron induced reactions on {sup 233,234,236}U, {sup 237}Np, {sup 238,242}Pu, {sup 241,243}Am, {sup 242,246}Cm carried out in the energy range 1 keV-20 MeV with EMPIRE code are presented, emphasizing the fission channel. Beside a consistent, accurate set of evaluations, the paper contains arguments supporting the choice of the reaction models and input parameters. A special attention is paid to the fission parameters and their uncertainties.

Sin, M.; Oblozinsky, P.; Herman,M.; Capote,R.

2010-04-30T23:59:59.000Z

193

Fluorescent image tracking velocimeter  

DOE Patents [OSTI]

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

Shaffer, Franklin D. (Library, PA)

1994-01-01T23:59:59.000Z

194

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

SciTech Connect (OSTI)

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

Brown, L.C.

2000-03-20T23:59:59.000Z

195

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

SciTech Connect (OSTI)

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

L.C. BROWN

2001-09-30T23:59:59.000Z

196

Recent progress in the study of fission barriers in covariant density functional theory  

E-Print Network [OSTI]

Recent progress in the study of fission barriers of actinides and superheavy nuclei within covariant density functional theory is overviewed.

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

2012-05-10T23:59:59.000Z

197

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

SciTech Connect (OSTI)

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.

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

2011-09-29T23:59:59.000Z

198

E-Print Network 3.0 - advanced fission reactors Sample Search...  

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

fission reactors, which release energy by splitting atoms... ) International Thermonuclear Experimental Reactor (ITER), which will be ... Source: Fusiongnition Research...

199

Recoil-alpha-fission and recoil-alpha-alpha-fission events observed in the reaction Ca-48 + Am-243  

E-Print Network [OSTI]

Products of the fusion-evaporation reaction Ca-48 + Am-243 were studied with the TASISpec set-up at the gas-filled separator TASCA at the GSI Helmholtzzentrum f\\"ur Schwerionenforschung. Amongst the detected thirty correlated alpha-decay chains associated with the production of element Z=115, two recoil-alpha-fission and five recoil-alpha-alpha-fission events were observed. The latter are similar to four such events reported from experiments performed at the Dubna gas-filled separator. Contrary to their interpretation, we propose an alternative view, namely to assign eight of these eleven decay chains of recoil-alpha(-alpha)-fission type to start from the 3n-evaporation channel 115-288. The other three decay chains remain viable candidates for the 2n-evaporation channel 115-289.

U. Forsberg; D. Rudolph; L. -L. Andersson; A. Di Nitto; Ch. E. Dllmann; J. M. Gates; P. Golubev; K. E. Gregorich; C. J. Gross; R. -D. Herzberg; F. P. Hessberger; J. Khuyagbaatar; J. V. Kratz; K. Rykaczewski; L. G. Sarmiento; M. Schdel; A. Yakushev; S. berg; D. Ackermann; M. Block; H. Brand; B. G. Carlsson; D. Cox; X. Derkx; J. Dobaczewski; K. Eberhardt; J. Even; C. Fahlander; J. Gerl; E. Jger; B. Kindler; J. Krier; I. Kojouharov; N. Kurz; B. Lommel; A. Mistry; C. Mokry; W. Nazarewicz; H. Nitsche; J. P. Omtvedt; P. Papadakis; I. Ragnarsson; J. Runke; H. Schaffner; B. Schausten; Y. Shi; P. Thrle-Pospiech; T. Torres; T. Traut; N. Trautmann; A. Trler; A. Ward; D. E. Ward; N. Wiehl

2015-02-10T23:59:59.000Z

200

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

SciTech Connect (OSTI)

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.

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

2006-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

INT Program INT13-3 Quantitative Large Amplitude Shape Dynamics: fission and heavy ion fusion  

E-Print Network [OSTI]

INT Program INT13-3 Quantitative Large Amplitude Shape Dynamics: fission and heavy ion fusion Talou, LANL "Fundamental and Applied Nuclear Fission Research at LANL" · 11:00 am: Anatoli Afanasjev, Mississippi State Univ "Fission in covariant DFT: status and open questions" Wednesday, October 2, 2013 Room C

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

202

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

SciTech Connect (OSTI)

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

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

1983-01-01T23:59:59.000Z

203

Track 4: Employee Health and Wellness  

Broader source: Energy.gov [DOE]

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

204

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

SciTech Connect (OSTI)

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

Holden, N.E.

1989-08-01T23:59:59.000Z

205

The translational landscape of fission yeast meiosis and sporulation  

E-Print Network [OSTI]

of multiple regulatory layers shapes gene expression in fission yeast. Mol Cell 26, 145-55 (2007). 24. Matia-Gonzalez, A.M., Hasan, A., Moe, G.H., Mata, J. & Rodriguez-Gabriel, M.A. Functional characterization of Upf1 targets in Schizosaccharomyces pombe...

Duncan, Caia D. S.; Mata, Juan

2014-06-15T23:59:59.000Z

206

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

E-Print Network [OSTI]

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

Reif, Rafael

207

Validation of MCNPX-PoliMi Fission Models  

SciTech Connect (OSTI)

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

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

2012-10-01T23:59:59.000Z

208

Characteristics of the samples in the FNG fission deposit collection  

SciTech Connect (OSTI)

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

Meadows, J.W.

1990-12-01T23:59:59.000Z

209

Reactor as a Source of Antineutrinos: Thermal Fission Energy  

E-Print Network [OSTI]

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

V. Kopeikin; L. Mikaelyan; V. Sinev

2004-10-07T23:59:59.000Z

210

Science based stockpile stewardship, uncertainty quantification, and fission fragment beams  

SciTech Connect (OSTI)

Stewardship of this nation's nuclear weapons is predicated on developing a fundamental scientific understanding of the physics and chemistry required to describe weapon performance without the need to resort to underground nuclear testing and to predict expected future performance as a result of intended or unintended modifications. In order to construct more reliable models, underground nuclear test data is being reanalyzed in novel ways. The extent to which underground experimental data can be matched with simulations is one measure of the credibility of our capability to predict weapon performance. To improve the interpretation of these experiments with quantified uncertainties, improved nuclear data is required. As an example, the fission yield of a device was often determined by measuring fission products. Conversion of the measured fission products to yield was accomplished through explosion code calculations (models) and a good set of nuclear reaction cross-sections. Because of the unique high-fluence environment of an exploding nuclear weapon, many reactions occurred on radioactive nuclides, for which only theoretically calculated cross-sections are available. Inverse kinematics reactions at CARIBU offer the opportunity to measure cross-sections on unstable neutron-rich fission fragments and thus improve the quality of the nuclear reaction cross-section sets. One of the fission products measured was {sup 95}Zr, the accumulation of all mass 95 fission products of Y, Sr, Rb and Kr (see Fig. 1). Subsequent neutron-induced reactions on these short lived fission products were assumed to cancel out - in other words, the destruction of mass 95 nuclides was more or less equal to the production of mass 95 nuclides. If a {sup 95}Sr was destroyed by an (n,2n) reaction it was also produced by (n,2n) reactions on {sup 96}Sr, for example. However, since these nuclides all have fairly short half-lives (seconds to minutes or even less), no experimental nuclear reaction cross-sections exist, and only theoretically modeled cross-sections are available. Inverse kinematics reactions at CARIBU offer the opportunity, should the beam intensity be sufficient, to measure cross-sections on a few important nuclides in order to benchmark the theoretical calculations and significantly improve the nuclear data. The nuclides in Fig. 1 are prioritized by importance factor and displayed in stoplight colors, green the highest and red the lowest priority.

Stoyer, M A; McNabb, D; Burke, J; Bernstein, L A; Wu, C Y

2009-09-14T23:59:59.000Z

211

Recent MELCOR and VICTORIA Fission Product Research at the NRC  

SciTech Connect (OSTI)

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

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

1999-01-21T23:59:59.000Z

212

Phase 1 Space Fission Propulsion Energy Source Design  

SciTech Connect (OSTI)

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

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

2002-07-01T23:59:59.000Z

213

Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U  

SciTech Connect (OSTI)

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 {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd 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 {approx}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 {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

Selby, H.D., E-mail: hds@lanl.go [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

2010-12-15T23:59:59.000Z

214

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

DOE Patents [OSTI]

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

Herrmann, Steven Douglas

2014-05-27T23:59:59.000Z

215

The Majorana Parts Tracking Database  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

216

The Majorana Parts Tracking Database  

E-Print Network [OSTI]

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

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

2015-02-05T23:59:59.000Z

217

Robotic vehicle with multiple tracked mobility platforms  

DOE Patents [OSTI]

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

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

2012-07-24T23:59:59.000Z

218

Delayed neutron data and group parameters for 43 fissioning systems  

SciTech Connect (OSTI)

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

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

1989-10-01T23:59:59.000Z

219

Method of fission heat flux determination from experimental data  

DOE Patents [OSTI]

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

Paxton, Frank A. (Schenectady, NY)

1999-01-01T23:59:59.000Z

220

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

SciTech Connect (OSTI)

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

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

1992-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
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221

Microscopic cold fission yields of {sup 252}Cf  

SciTech Connect (OSTI)

We show that the sharp maximum corresponding to {sup 107}Mo in the fragment distribution of the {sup 252}Cf cold fission is actually a Sn-like radioactivity, similar to other decay processes in which magic nuclei are involved, namely alpha decay and heavy cluster emission, also called Pb-like radioactivity. It turns out that the mass asymmetry degree of freedom has a key role in connecting initial Sn with the final Mo isotopes along the fission path. We investigate the cold rearrangement of nucleons within the framework of the two-center shell model in order to compute the cold valleys in the charge equilibrated fragmentation potential. The fission yields are estimated by using the semiclassical penetration approach. We consider 5 degrees of freedom, namely the interfragment distance, the shapes of fragments, the neck parameter, and mass asymmetry. We found an isomeric minimum between the internal and external barriers. It turns out that the inner cold valley of the total potential energy is connected to the doubly magic isotope {sup 132}Sn.

Mirea, M. [National Institute of Physics and Nuclear Engineering, 407 Atomistilor, RO-077125 Bucharest-Magurele (Romania); Delion, D. S. [National Institute of Physics and Nuclear Engineering, 407 Atomistilor, RO-077125 Bucharest-Magurele (Romania); Academy of Romanian Scientists 54 Splaiul Independentei, RO-050094 Bucharest (Romania); Sandulescu, A. [Academy of Romanian Scientists 54 Splaiul Independentei, RO-050094 Bucharest (Romania); Institute for Advanced Studies in Physics, 129 Calea Victoriei, Bucharest (Romania)

2010-04-15T23:59:59.000Z

222

Monitoring system for a liquid-cooled nuclear fission reactor  

DOE Patents [OSTI]

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

DeVolpi, Alexander (Bolingbrook, IL)

1987-01-01T23:59:59.000Z

223

(Fission product transport experiments (HFR-B1))  

SciTech Connect (OSTI)

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

Myers, B.F.

1989-12-05T23:59:59.000Z

224

Direct fission fragment energy converter - Magnetic collimator option  

SciTech Connect (OSTI)

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

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

2006-07-01T23:59:59.000Z

225

Nuclear fission and nuclear safeguards: Common technologies and challenges  

SciTech Connect (OSTI)

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

Keepin, G.R.

1989-01-01T23:59:59.000Z

226

Tracking Radioactive Sources in Commerce  

E-Print Network [OSTI]

Area Network­mobile phone, ethernet and/or satellite ? security--encryption, short broadcast bursts Randy Walker, Robert Abercrombie, Rocky Cline, Sabrina Phillips; Oak Ridge National Laboratory Frederick security by commercial shippers ? Knowledge of routes routinely taken ? Inability to track location

227

Comparison of Current LCD Tracking Options  

E-Print Network [OSTI]

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

California at Santa Cruz, University of

228

Childhood Cancer Tracking Initiative in Massachusetts  

E-Print Network [OSTI]

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

229

Track 5: Integration of Safety Into Design  

Broader source: Energy.gov [DOE]

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

230

Track 6: Integrating Safety Into Security Operations  

Broader source: Energy.gov [DOE]

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

231

Uncertainties analysis of fission fraction for reactor antineutrino experiments using DRAGON  

E-Print Network [OSTI]

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

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

2014-05-27T23:59:59.000Z

232

Group Constants Generation of the Pseudo Fission Products for Fast Reactor Burnup Calculations  

SciTech Connect (OSTI)

The pseudo fission products for the burnup calculations of the liquid metal fast reactor were generated. The cross-section data and fission product yield data of ENDF/B-VI were used for the pseudo fission product data of U-235, U-238, Pu-239, Pu-240, Pu-241, and Pu-242. The pseudo fission product data can be used with the KAFAX-F22 or -E66, which are the MATXS-format libraries for analyses of the liquid metal fast reactor at KAERI and were distributed through the OECD/NEA. The 80-group MATXS-format libraries of the 172 fission products were generated and the burnup chains for generation of the pseudo fission products were prepared.

Gil, Choong-Sup; Kim, Do Heon; Chang, Jonghwa [Korea Atomic Energy Research Institute, 150 Dukjin-dong, Yusung-gu, Taejon (Korea, Republic of)

2005-05-24T23:59:59.000Z

233

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

SciTech Connect (OSTI)

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

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

2014-05-09T23:59:59.000Z

234

Experimental Measurements of Short-Lived Fission Products from Uranium, Neptunium, Plutonium and Americium  

SciTech Connect (OSTI)

Fission yields are especially well characterized for long-lived fission products. Modeling techniques incorporate numerous assumptions and can be used to deduce information about the distribution of short-lived fission products. This work is an attempt to gather experimental (model-independent) data on the short-lived fission products. Fissile isotopes of uranium, neptunium, plutonium and americium were irradiated under pulse conditions at the Washington State University 1 MW TRIGA reactor to achieve ~108 fissions. The samples were placed on a HPGe (high purity germanium) detector to begin counting in less than 3 minutes post irradiation. The samples were counted for various time intervals ranging from 5 minutes to 1 hour. The data was then analyzed to determine which radionuclides could be quantified and compared to the published fission yield data.

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

2009-11-01T23:59:59.000Z

235

Rail ClipsRail Clips Track Renewal  

E-Print Network [OSTI]

Rail ClipsRail Clips and Track Renewal ver. 1 ME 6222: Manufacturing Processes and Systems Prof. J 2009 7 #12;Track Renewal ­ Tie replacement ballast packingTie replacement, ballast packing ME 6222: Manufacturing Processes and Systems Prof. J.S. Colton © GIT 2009 8 #12;Track Renewal ME 6222: Manufacturing

Colton, Jonathan S.

236

Train track expansions of measured foliations February 16, 2003  

E-Print Network [OSTI]

Train track expansions of measured foliations Lee Mosher February 16, 2003 Contents 1 Introduction foliations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.5 Train tracks and train track's classification of mapping classes . . . . . . . . . . . . . . 47 3 Train tracks 49 3.1 Pretracks

Mosher, Lee

237

Train track expansions of measured foliations December 28, 2003  

E-Print Network [OSTI]

Train track expansions of measured foliations Lee Mosher December 28, 2003 Contents 1 Introduction foliations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.5 Train tracks and train track's classification of mapping classes . . . . . . . . . . . . . . 53 3 Train tracks 55 3.1 Pretracks

Mosher, Lee

238

E-Print Network 3.0 - affordable fission engine Sample Search...  

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

nearly doubled, from 528 million to 936 million... specific parts, one of which covers fusion, fission and radiation protection research, including... the International...

239

E-Print Network 3.0 - absolute thermal fission Sample Search...  

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

- Department of Geology and Geophysics, Yale University; Garver, John I. - Department of Geology, Union College Collection: Geosciences 28 Nuclear fission time measurements as a...

240

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

SciTech Connect (OSTI)

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

Vogt, R; Randrup, J

2011-09-14T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

E-Print Network [OSTI]

on metabolic data for plutonium were used to estimate intake, and were generated by INDOS, a computer code used for internal dosimetry calcuiations. The period of intake was assumed to be equal to the time of residence on the island. Effective dose... from exposure to cesium-137. The cesium dose was determined to be higher for older members of the population, but no correlation to plutonium results was found after data analysis. ACKNOWLEDGEMENTS I wish to express my sincere appreciation...

Taylor, George Anthony

1989-01-01T23:59:59.000Z

242

Infrared tag and track technique  

DOE Patents [OSTI]

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

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

2007-12-04T23:59:59.000Z

243

Participatory Sensing in Commerce: Using Mobile Camera Phones to Track Market Price Dispersion  

E-Print Network [OSTI]

Participatory Sensing in Commerce: Using Mobile Camera Phones to Track Market Price Dispersion In economics, price dispersion refers to the price difference of a homogeneous good across different vendors. According to [1] "The empirical evidence suggests that price dispersion in both online and offline markets

Bulusu, Nirupama

244

Analysis of Fission Products on the AGR-1 Capsule Components  

SciTech Connect (OSTI)

The components of the AGR-1 irradiation capsules were analyzed to determine the retained inventory of fission products in order to determine the extent of in-pile fission product release from the fuel compacts. This includes analysis of (i) the metal capsule components, (ii) the graphite fuel holders, (iii) the graphite spacers, and (iv) the gas exit lines. The fission products most prevalent in the components were Ag-110m, Cs 134, Cs 137, Eu-154, and Sr 90, and the most common location was the metal capsule components and the graphite fuel holders. Gamma scanning of the graphite fuel holders was also performed to determine spatial distribution of Ag-110m and radiocesium. Silver was released from the fuel components in significant fractions. The total Ag-110m inventory found in the capsules ranged from 1.210 2 (Capsule 3) to 3.810 1 (Capsule 6). Ag-110m was not distributed evenly in the graphite fuel holders, but tended to concentrate at the axial ends of the graphite holders in Capsules 1 and 6 (located at the top and bottom of the test train) and near the axial center in Capsules 2, 3, and 5 (in the center of the test train). The Ag-110m further tended to be concentrated around fuel stacks 1 and 3, the two stacks facing the ATR reactor core and location of higher burnup, neutron fluence, and temperatures compared with Stack 2. Detailed correlation of silver release with fuel type and irradiation temperatures is problematic at the capsule level due to the large range of temperatures experienced by individual fuel compacts in each capsule. A comprehensive Ag 110m mass balance for the capsules was performed using measured inventories of individual compacts and the inventory on the capsule components. For most capsules, the mass balance was within 11% of the predicted inventory. The Ag-110m release from individual compacts often exhibited a very large range within a particular capsule.

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

2013-03-01T23:59:59.000Z

245

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

SciTech Connect (OSTI)

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

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

2012-09-01T23:59:59.000Z

246

NEET Micro-Pocket Fission Detector Final Project report  

SciTech Connect (OSTI)

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

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

2014-09-01T23:59:59.000Z

247

Fission meter and neutron detection using poisson distribution comparison  

DOE Patents [OSTI]

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

Rowland, Mark S; Snyderman, Neal J

2014-11-18T23:59:59.000Z

248

Radiolysis Concerns for Water Shielding in Fission Surface Power Applications  

SciTech Connect (OSTI)

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

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

2008-01-21T23:59:59.000Z

249

Singlet Fission | MIT-Harvard Center for Excitonics  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmitted forHighlightsSeminarsSilicon spongeComputingCellFission April 3, 2012

250

Cryogenic method for measuring nuclides and fission gases  

DOE Patents [OSTI]

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

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

1980-05-02T23:59:59.000Z

251

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

E-Print Network [OSTI]

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

Reed, Mark Wilbert

2011-01-01T23:59:59.000Z

252

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

SciTech Connect (OSTI)

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.

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

2005-12-01T23:59:59.000Z

253

Resonant tunneling and the bimodal symmetric fission of sup 258 Fm  

SciTech Connect (OSTI)

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

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

1991-02-25T23:59:59.000Z

254

INT Program 13-3 Quantitative Large Amplitude Shape Dynamics: fission and heavy ion fusion  

E-Print Network [OSTI]

INT Program 13-3 Quantitative Large Amplitude Shape Dynamics: fission and heavy ion fusion Workshop on: Experimental Status and Prospects October 14 - 18, 2013 Talks are 40 minutes long and followed and nuclear data Katsuhisa Nishio, JAEA 2:00 Fission shape evolution by Brownian motion Jorgen Randrup, LBNL 3

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

255

Structural basis for recruitment of mitochondrial fission complexes by Fis1  

E-Print Network [OSTI]

Structural basis for recruitment of mitochondrial fission complexes by Fis1 Yan Zhang and David C mitochondrial fission complex, the outer membrane protein Fis1 recruits the dynamin-related GTPase Dnm1 to mitochondria. Fis1 contains a tetratricopeptide repeat (TPR) domain and interacts with Dnm1 via the molecular

Chan, David

256

New fission fragment distributions and r-process origin of the rare-earth elements  

E-Print Network [OSTI]

Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers A > 140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular the fission fragment yields determine the creation of 110 140.

Goriely, S; Lemaitre, J -F; Panebianco, S; Dubray, N; Hilaire, S; Bauswein, A; Janka, H -Thomas

2013-01-01T23:59:59.000Z

257

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

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

258

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

SciTech Connect (OSTI)

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

Stansfield, O.M.

1990-03-15T23:59:59.000Z

259

The neutronics studies of fusion fission hybrid power reactor  

SciTech Connect (OSTI)

In this paper, a series of neutronics analysis of hybrid power reactor is proposed. The ideas of loading different fuels in a modular-type fission blanket is analyzed, fitting different level of fusion developments, i.e., the current experimental power output, the level can be obtained in the coming future and the high-power fusion reactor like ITER. The energy multiplication of fission blankets and tritium breeding ratio are evaluated as the criterion of design. The analysis is implemented based on the D-type simplified model, aiming to find a feasible 1000MWe hybrid power reactor for 5 years' lifetime. Three patterns are analyzed: 1) for the low fusion power, the reprocessed fuel is chosen. The fuel with high plutonium content is loaded to achieve large energy multiplication. 2) For the middle fusion power, the spent fuel from PWRs can be used to realize about 30 times energy multiplication. 3) For the high fusion power, the natural uranium can be directly used and about 10 times energy multiplication can be achieved.

Zheng Youqi; Wu Hongchun; Zu Tiejun; Yang Chao; Cao Liangzhi [School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi, 710049 (China)

2012-06-19T23:59:59.000Z

260

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

SciTech Connect (OSTI)

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

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

2008-11-15T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

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

SciTech Connect (OSTI)

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

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

2008-12-15T23:59:59.000Z

262

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

SciTech Connect (OSTI)

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.

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

2013-03-15T23:59:59.000Z

263

Tracking system for solar collectors  

DOE Patents [OSTI]

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

Butler, B.

1980-10-01T23:59:59.000Z

264

Tracking system for solar collectors  

DOE Patents [OSTI]

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

Butler, Barry L. (Golden, CO)

1984-01-01T23:59:59.000Z

265

Two-axis tracking solar collector mechanism  

DOE Patents [OSTI]

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

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

1990-01-01T23:59:59.000Z

266

Two-axis tracking solar collector mechanism  

DOE Patents [OSTI]

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

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

1992-01-01T23:59:59.000Z

267

Two-axis tracking solar collector mechanism  

DOE Patents [OSTI]

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

Johnson, K.C.

1992-12-08T23:59:59.000Z

268

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

E-Print Network [OSTI]

detector based on photovoltaic cells M. Petita , T. Ethvignota , T. Graniera,?, R.C. Haightb , J.M. O fission fragment detector based on compensated photovoltaic cells has been developed. The compensated. Keywords: Fission; Fission detection; Compensated detector; Lead slowing-down spectrometer; Photovoltaic

Danon, Yaron

269

Energy Intensity Baselining and Tracking Guidance  

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

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

270

Energy Intensity Baselining and Tracking Guidance  

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

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

271

Automated micro-tracking planar solar concentrators  

E-Print Network [OSTI]

tracking mechanics. Solar trackers rotate the solar panel orwith traditional solar trackers but its unique geometrysolar intensity depends on the role the micro micro-tracker

Hallas, Justin Matthew

2011-01-01T23:59:59.000Z

272

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

E-Print Network [OSTI]

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

Richardson, Daniel C.

273

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

E-Print Network [OSTI]

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

Barthelat, Francois

274

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

E-Print Network [OSTI]

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

275

Rapid disappearance of shell effects in the fission of transfermium nuclei  

SciTech Connect (OSTI)

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

Hulet, E.K.

1983-01-01T23:59:59.000Z

276

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

SciTech Connect (OSTI)

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

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

2014-10-01T23:59:59.000Z

277

Thermal Performance of Deep-Burn Fusion-Fission Hybrid Waste in a Repository  

SciTech Connect (OSTI)

The Laser Inertial Confinement Fusion Fission Energy (LIFE) Engine [1] combines a neutron-rich but energy-poor inertial fusion system with an energy-rich but neutron-poor subcritical fission blanket. Because approximately 80% of the LIFE Engine energy is produced from fission, the requirements for laser efficiency and fusion target performance are relaxed, compared to a pure-fusion system, and hence a LIFE Engine prototype can be based on target performance in the first few years of operation of the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory (LLNL). Similarly, because of the copious fusion neutrons, the fission blanket can be run in a subcritical, driven, mode, without the need for control rods or other sophisticated reactivity control systems. Further, because the fission blanket is inherently subcritical, fission fuels that can be used in LIFE Engine designs include thorium, depleted uranium, natural uranium, spent light water reactor fuel, highly enriched uranium, and plutonium. Neither enrichment nor reprocessing is required for the LIFE Engine fuel cycle, and burnups to 99% fraction of initial metal atoms (FIMA) being fissioned are envisioned. This paper discusses initial calculations of the thermal behavior of spent LIFE fuel following completion of operation in the LIFE Engine [2]. The three time periods of interest for thermal calculations are during interim storage (probably at the LIFE Engine site), during the preclosure operational period of a geologic repository, and after closure of the repository.

Blink, J A; Chipman, V; Farmer, J; Shaw, H; Zhao, P

2008-11-25T23:59:59.000Z

278

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

SciTech Connect (OSTI)

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

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

1987-05-01T23:59:59.000Z

279

Position and orientation tracking system  

DOE Patents [OSTI]

A position and orientation tracking system presents a laser scanning apparatus having two measurement pods, a control station, and a detector array. The measurement pods can be mounted in the dome of a radioactive waste storage silo. Each measurement pod includes dual orthogonal laser scanner subsystems. The first laser scanner subsystem is oriented to emit a first line laser in the pan direction. The second laser scanner is oriented to emit a second line laser in the tilt direction. Both emitted line lasers scan planes across the radioactive waste surface to encounter the detector array mounted on a target robotic vehicle. The angles of incidence of the planes with the detector array are recorded by the control station. Combining measurements describing each of the four planes provides data for a closed form solution of the algebraic transform describing the position and orientation of the target robotic vehicle. 14 figs.

Burks, B.L.; DePiero, F.W.; Armstrong, G.A.; Jansen, J.F.; Muller, R.C.; Gee, T.F.

1998-05-05T23:59:59.000Z

280

Position and orientation tracking system  

DOE Patents [OSTI]

A position and orientation tracking system presents a laser scanning appaus having two measurement pods, a control station, and a detector array. The measurement pods can be mounted in the dome of a radioactive waste storage silo. Each measurement pod includes dual orthogonal laser scanner subsystems. The first laser scanner subsystem is oriented to emit a first line laser in the pan direction. The second laser scanner is oriented to emit a second line laser in the tilt direction. Both emitted line lasers scan planes across the radioactive waste surface to encounter the detector array mounted on a target robotic vehicle. The angles of incidence of the planes with the detector array are recorded by the control station. Combining measurements describing each of the four planes provides data for a closed form solution of the algebraic transform describing the position and orientation of the target robotic vehicle.

Burks, Barry L. (Oak Ridge, TN); DePiero, Fred W. (Knoxville, TN); Armstrong, Gary A. (Oak Ridge, TN); Jansen, John F. (Knoxville, TN); Muller, Richard C. (Oak Ridge, TN); Gee, Timothy F. (Riceville, TN)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Rotorcraft Trajectory Tracking by Supervised NLI Control  

E-Print Network [OSTI]

for a four rotor aircraft with fixed pitch blades, or rotorcraft, are considered. One important limitation tracking by a four rotor aircraft is considered. After introducing the flight dynamics equations for the four rotor aircraft, a trajectory tracking control structure based on a two layer non linear inverse

Boyer, Edmond

282

Energy-Efficient Computing for Wildlife Tracking  

E-Print Network [OSTI]

Energy-Efficient Computing for Wildlife Tracking: Design Tradeoffs and Early Experiences with ZebraNet Philo Juang Hidekazu Oki Yong Wang Margaret Martonosi Li-Shiuan Peh Dan Rubenstein Dept. of Electrical Princeton University ZebraNet Project VET TES EN NOV TAM TVM Current Tracking Technology Most common: VHF

Singh, Jaswinder Pal

283

User centered story tracking Ilija Subasic  

E-Print Network [OSTI]

and their evolu- tion and comprehending the general the story development. This situation calls for systems thatUser centered story tracking Ilija Subasi´c Katholieke Universiteit Leuven Leuven-Heverlee, Belgium is to identify and highlight these changes to better enable readers to track stories. In this work we restrict

Hammerton, James

284

DISTRIBUTED EVENT LOCALIZATION AND TRACKING ALGORITHM (DELTA)  

E-Print Network [OSTI]

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

Braun, Torsten

285

Status Report on REC Verification, Tracking  

E-Print Network [OSTI]

RECs 11. Ability to prevent double-selling of attributes 12. Coordination between electricity tracking · Acceptance and support of REC market by the regulatory community, OR · Policy driver (GHG regulation · Mission: Provide a forum for coordination and cooperation of certificate tracking systems in North America

286

GPU COMPUTING FOR PARTICLE TRACKING  

SciTech Connect (OSTI)

This is a feasibility study of using a modern Graphics Processing Unit (GPU) to parallelize the accelerator particle tracking code. To demonstrate the massive parallelization features provided by GPU computing, a simplified TracyGPU program is developed for dynamic aperture calculation. Performances, issues, and challenges from introducing GPU are also discussed. General purpose Computation on Graphics Processing Units (GPGPU) bring massive parallel computing capabilities to numerical calculation. However, the unique architecture of GPU requires a comprehensive understanding of the hardware and programming model to be able to well optimize existing applications. In the field of accelerator physics, the dynamic aperture calculation of a storage ring, which is often the most time consuming part of the accelerator modeling and simulation, can benefit from GPU due to its embarrassingly parallel feature, which fits well with the GPU programming model. In this paper, we use the Tesla C2050 GPU which consists of 14 multi-processois (MP) with 32 cores on each MP, therefore a total of 448 cores, to host thousands ot threads dynamically. Thread is a logical execution unit of the program on GPU. In the GPU programming model, threads are grouped into a collection of blocks Within each block, multiple threads share the same code, and up to 48 KB of shared memory. Multiple thread blocks form a grid, which is executed as a GPU kernel. A simplified code that is a subset of Tracy++ [2] is developed to demonstrate the possibility of using GPU to speed up the dynamic aperture calculation by having each thread track a particle.

Nishimura, Hiroshi; Song, Kai; Muriki, Krishna; Sun, Changchun; James, Susan; Qin, Yong

2011-03-25T23:59:59.000Z

287

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

E-Print Network [OSTI]

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

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

2001-01-01T23:59:59.000Z

288

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

E-Print Network [OSTI]

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

Wene, C O

1976-01-01T23:59:59.000Z

289

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

DOE Patents [OSTI]

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.

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

2007-10-02T23:59:59.000Z

290

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

SciTech Connect (OSTI)

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

Beyer, Carl E.; Turnbull, Andrew J.

2010-01-29T23:59:59.000Z

291

Radiological Aspects of Deep-Burn Fusion-Fission Hybrid Waste in a Repository  

SciTech Connect (OSTI)

The quantity, radioactivity, and isotopic characteristics of the spent fission fuel from a hybrid fusion-fission system capable of extremely high burnups are described. The waste generally has higher activity per unit mass of heavy metal, but much lower activity per unit energy generated. The very long-term radioactivity is dominated by fission products. Simple scaling calculations suggest that the dose from a repository containing such waste would be dominated by {sup 129}I, {sup 135}Cs, and {sup 242}Pu. Use of such a system for generating energy would greatly reduce the need for repository capacity.

Shaw, H F; Blink, J A; Farmer, J C; Karmer, K J; Latkowski, J F; Zhao, P

2008-11-25T23:59:59.000Z

292

Deep Atomic Binding (DAB) Approach in Interpretation of Fission Products Behavior in Terrestrial and Water Ecosystems  

SciTech Connect (OSTI)

A large number of studies and models were established to explain the fission products (FP) behavior within terrestrial and water ecosystems, but a number of behaviors were non understandable, which always attributed to unknown reasons. According to DAB hypothesis, almost all fission products behaviors in terrestrial and water ecosystems could be interpreted in a wide coincidence. The gab between former models predictions, and field behavior of fission products after accidents like Chernobyl have been explained. DAB represents a tool to reduce radio-phobia as well as radiation protection expenses. (author)

Ajlouni, Abdul-Wali M.S. [Ministry of Energy and Mineral Resources, Amman 11814 (Jordan)

2006-07-01T23:59:59.000Z

293

ATLAS Tracking Event Data Model -- 12.0.0  

E-Print Network [OSTI]

viewcvs-all.cgi/offline/? cvsroot=atlas : Tracking/TrkEvent/all.cgi/ offline/? cvsroot=atlas : Tracking/TrkEvent/all.cgi/offline/? cvsroot=atlas : Tracking/TrkDetDescr/

Akesson, F.; ATLAS

2009-01-01T23:59:59.000Z

294

Enhancements to System for Tracking Radioactive Waste Shipments...  

Energy Savers [EERE]

Multiple Users January 30, 2013 - 12:00pm Addthis Transportation Tracking and Communication System users can now track shipments of radioactive materials and access...

295

Extracting and Using Data From Tracking Systems | Department...  

Energy Savers [EERE]

Extracting and Using Data From Tracking Systems Extracting and Using Data From Tracking Systems Better Buildings Neighborhood Program Data and Evaluation Peer Exchange Call:...

296

ORO Verification of Employment Tracking System(VETS) PIA, Oak...  

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

Verification of Employment Tracking System(VETS) PIA, Oak ridge Operations Office ORO Verification of Employment Tracking System(VETS) PIA, Oak ridge Operations Office ORO...

297

ORO Office Safeguards and Security Clearance Tracking System...  

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

Office Safeguards and Security Clearance Tracking System and Visitor Control System PIA, Oak Ridge Operations Office ORO Office Safeguards and Security Clearance Tracking System...

298

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

SciTech Connect (OSTI)

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

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

2000-05-16T23:59:59.000Z

299

/sup 3/He-induced fission of nuclei 159  

SciTech Connect (OSTI)

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

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

1983-09-01T23:59:59.000Z

300

E-Print Network 3.0 - amount gaseous fission Sample Search Results  

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

) reports that the amount of non-gaseous nuclides retained on the filters of the Windscale pile... . Petersen Abstract. The fission-product release to the atmosphere from a...

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

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

E-Print Network [OSTI]

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

Reusswig, Philip David

302

E-Print Network 3.0 - absolute fission yields Sample Search Results  

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

Physics 90 H-atom high-n Rydberg time-of-flight spectroscopy of CH bond fission in acrolein dissociated at 193 nm Summary: H-atom high-n Rydberg time-of-flight spectroscopy of...

303

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

E-Print Network [OSTI]

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

Shultis, J. Kenneth

304

Geminate and non-geminate recombination of triplet excitons formed by singlet fission  

E-Print Network [OSTI]

fis- sion material would ideally have degenerate singlet and triplet-pair states. However, with this energy level con- figuration, the inverse process of singlet fission - triplet- triplet annihilation - becomes a possible recombination pathway...

Bayliss, Sam L.; Chepelianskii, Alexei D.; Sepe, Alessandro; Walker, Brian J.; Ehrler, Bruno; Bruzek, Matthew J.; Anthony, John E.; Greenham, Neil C.

2014-07-04T23:59:59.000Z

305

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

E-Print Network [OSTI]

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

Thompson, Nicholas J.

306

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

SciTech Connect (OSTI)

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

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

2013-04-19T23:59:59.000Z

307

Fission-suppressed fusion breeder on the thorium cycle and nonproliferation  

SciTech Connect (OSTI)

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

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

2012-06-19T23:59:59.000Z

308

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

SciTech Connect (OSTI)

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

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

1981-04-01T23:59:59.000Z

309

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

E-Print Network [OSTI]

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

N. Schunck; D. Duke; H. Carr

2015-01-23T23:59:59.000Z

310

Class 3 Tracking and Monitoring System Report  

SciTech Connect (OSTI)

The objective of Class 3 tracking system are to assist DOE in tracking and performance and progress of these projects and to capture the technical and financial information collected during the projects' monitoring phase. The captured information was used by DOE project managers and BDM-Oklahoma staff for project monitoring and evaluation, and technology transfer activities. The proposed tracking system used the Class Evaluation Executive Report (CLEVER), a relation database for storing and disseminating class project data; GeoGraphix, a geological and technical analysis and mapping software system; the Tertiary Oil Recovery Information System (TORIS) database; and MS-Project, a project management software system.

Safely, Eugene; Salamy, S. Phillip

1999-11-29T23:59:59.000Z

311

TRACKING CODE DEVELOPMENT FOR BEAM DYNAMICS OPTIMIZATION  

SciTech Connect (OSTI)

Dynamic aperture (DA) optimization with direct particle tracking is a straight forward approach when the computing power is permitted. It can have various realistic errors included and is more close than theoretical estimations. In this approach, a fast and parallel tracking code could be very helpful. In this presentation, we describe an implementation of storage ring particle tracking code TESLA for beam dynamics optimization. It supports MPI based parallel computing and is robust as DA calculation engine. This code has been used in the NSLS-II dynamics optimizations and obtained promising performance.

Yang, L.

2011-03-28T23:59:59.000Z

312

A comparison of radioactive waste from first generation fusion reactors and fast fission reactors with actinide recycling  

SciTech Connect (OSTI)

Limitations of the fission fuel resources will presumably mandate the replacement of thermal fission reactors by fast fission reactors that operate on a self-sufficient closed fuel cycle. This replacement might take place within the next one hundred years, so the direct competitors of fusion reactors will be fission reactors of the latter rather than the former type. Also, fast fission reactors, in contrast to thermal fission reactors, have the potential for transmuting long-lived actinides into short-lived fission products. The associated reduction of the long-term activation of radioactive waste due to actinides makes the comparison of radioactive waste from fast fission reactors to that from fusion reactors more rewarding than the comparison of radioactive waste from thermal fission reactors to that from fusion reactors. Radioactive waste from an experimental and a commercial fast fission reactor and an experimental and a commercial fusion reactor has been characterized. The fast fission reactors chosen for this study were the Experimental Breeder Reactor 2 and the Integral Fast Reactor. The fusion reactors chosen for this study were the International Thermonuclear Experimental Reactor and a Reduced Activation Ferrite Helium Tokamak. The comparison of radioactive waste parameters shows that radioactive waste from the experimental fast fission reactor may be less hazardous than that from the experimental fusion reactor. Inclusion of the actinides would reverse this conclusion only in the long-term. Radioactive waste from the commercial fusion reactor may always be less hazardous than that from the commercial fast fission reactor, irrespective of the inclusion or exclusion of the actinides. The fusion waste would even be far less hazardous, if advanced structural materials, like silicon carbide or vanadium alloy, were employed.

Koch, M.; Kazimi, M.S.

1991-04-01T23:59:59.000Z

313

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

SciTech Connect (OSTI)

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

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

1989-05-01T23:59:59.000Z

314

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

E-Print Network [OSTI]

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

R. Rodriguez-Guzman; L. M. Robledo

2014-05-25T23:59:59.000Z

315

Comparison of Current LCD Tracking Options  

E-Print Network [OSTI]

Comparison of Current LCD Tracking Options Bruce Schumm Santa Cruz Institute for Particle Physics for new S design (pattern recognition, resolution) S detector in real trouble at low angle w/out beam

California at Santa Cruz, University of

316

HCI gesture tracking using wearable passive tags  

E-Print Network [OSTI]

In this thesis. a wearable system is developed to track hand gestures with passive RFID sensor tags. This system was composed of an ultra-high frequency reader and small, passive, finger-worn tags powered by scavenged RFID ...

Bainbridge, Rachel M

2010-01-01T23:59:59.000Z

317

SNIF: A Futuristic Neutrino Probe for Undeclared Nuclear Fission Reactors  

E-Print Network [OSTI]

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

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

2010-11-16T23:59:59.000Z

318

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

SciTech Connect (OSTI)

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

Troy Unruh; Michael Reichenberger; Phillip Ugorowski

2013-09-01T23:59:59.000Z

319

Baseline Glass Development for Combined Fission Products Waste Streams  

SciTech Connect (OSTI)

Borosilicate glass was selected as the baseline technology for immobilization of the Cs/Sr/Ba/Rb (Cs), lanthanide (Ln) and transition metal fission product (TM) waste steams as part of a cost benefit analysis study.[1] Vitrification of the combined waste streams have several advantages, minimization of the number of waste forms, a proven technology, and similarity to waste forms currently accepted for repository disposal. A joint study was undertaken by Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) to develop acceptable glasses for the combined Cs + Ln + TM waste streams (Option 1) and Cs + Ln combined waste streams (Option 2) generated by the AFCI UREX+ set of processes. This study is aimed to develop baseline glasses for both combined waste stream options and identify key waste components and their impact on waste loading. The elemental compositions of the four-corners study were used along with the available separations data to determine the effect of burnup, decay, and separations variability on estimated waste stream compositions.[2-5] Two different components/scenarios were identified that could limit waste loading of the combined Cs + LN + TM waste streams, where as the combined Cs + LN waste stream has no single component that is perceived to limit waste loading. Combined Cs + LN waste stream in a glass waste form will most likely be limited by heat due to the high activity of Cs and Sr isotopes.

Crum, Jarrod V.; Billings, Amanda Y.; Lang, Jesse B.; Marra, James C.; Rodriguez, Carmen P.; Ryan, Joseph V.; Vienna, John D.

2009-06-29T23:59:59.000Z

320

New developments in direct nuclear fission energy conversion devices  

SciTech Connect (OSTI)

Some experimental and theoretical results obtained in the investigations undertaken at the Central Institute of Physics (CIP) in Bucharest-Romania concerning the direct nuclear energy conversion into electrical energy are presented. Open-circuit voltages (U /SUB oc/ ) of tens of kV and short-circuit currents (J /SUB sc/ ) of several ..mu..A were obtained in experiments with vacuum fission-electric cells (FEC) developed in the CIP and irradiated in the VVR-S reactor at a 10/sup 9/ neutrons/cm/sup 2/s thermal neutron flux. A gas filled FEC (GAFFC) has been devised and tested in the reactor at the same neutron flux. With this GAFEC U /SUB oc/ of hundreds of kV, J /SUB sc/ of hundreds of ..mu..A and powers of hundreds of mW have been obtained. Our researches pointed out the essential part played by the electrons in the charge transport dynamics occuring in the FEC and the influence of the secondary emission on the FEC operation.

Ursu, I.; Badescu-Singureann, A.I.; Schachter, L.

1983-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Engineering Report on the Fission Gas Getter Concept  

SciTech Connect (OSTI)

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

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

2012-11-01T23:59:59.000Z

322

Feasibility study of a fission-suppressed tokamak fusion breeder  

SciTech Connect (OSTI)

The preliminary conceptual design of a tokamak fissile fuel producer is described. The blanket technology is based on the fission suppressed breeding concept where neutron multiplication occurs in a bed of 2 cm diameter beryllium pebbles which are cooled by helium at 50 atmospheres pressure. Uranium-233 is bred in thorium metal fuel elements which are in the form of snap rings attached to each beryllium pebble. Tritium is bred in lithium bearing material contained in tubes immersed in the pebble bed and is recovered by a purge flow of helium. The neutron wall load is 3 MW/m/sup 2/ and the blanket material is ferritic steel. The net fissile breeding ratio is 0.54 +- 30% per fusion reaction. This results in the production of 4900 kg of /sup 233/U per year from 3000 MW of fusion power. This quantity of fuel will provide makeup fuel for about 12 LWRs of equal thermal power or about 18 1 GW/sub e/ LWRs. The calculated cost of the produced uranium-233 is between $23/g and $53/g or equivalent to $10/kg to $90/kg of U/sub 3/O/sub 8/ depending on government financing or utility financing assumptions. Additional topics discussed in the report include the tokamak operating mode (both steady state and long pulse considered), the design and breeding implications of using a poloidal divertor for impurity control, reactor safety, the choice of a tritium breeder, and fuel management.

Moir, R.W.; Lee, J.D.; Neef, W.S.; Berwald, D.H.; Garner, J.K.; Whitley, R.H.; Ghoniem, N.; Wong, C.P.C.; Maya, I.; Schultz, K.R.

1984-12-01T23:59:59.000Z

323

Fusion materials irradiations at MaRIE's fission fusion facility  

SciTech Connect (OSTI)

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

Pitcher, Eric J [Los Alamos National Laboratory

2010-10-06T23:59:59.000Z

324

Spin Rotation of Formalism for Spin Tracking  

SciTech Connect (OSTI)

The problem of which coefficients are adequate to correctly represent the spin rotation in vector spin tracking for polarized proton and deuteron beams in synchrotrons is here re-examined in the light of recent discussions. The main aim of this note is to show where some previous erroneous results originated and how to code spin rotation in a tracking code. Some analysis of a recent experiment is presented that confirm the correctness of the assumptions.

Luccio,A.

2008-02-01T23:59:59.000Z

325

CPS October 2005 A Fast Track Approach to FusionA Fast Track Approach to Fusion  

E-Print Network [OSTI]

-full of ordinary water ( one egg cup full of heavy water) 200,000 kW-hours = (current UK electricity production and stars It involves fusing light nuclei (while fission splitting heavy nuclei) The most effective fusion process involves deuterium (heavy hydrogen) and tritium (super heavy hydrogen) heated to above 100 million

326

ENVIRONMENTAL STUDIES TRACK (B.S.) 2013-2014 CATALOG  

E-Print Network [OSTI]

June 2012 ENVIRONMENTAL STUDIES TRACK (B.S.) 2013-2014 CATALOG There are three tracks in Interdisciplinary Studies (IS). This handout is for the Environmental Studies track. Office Classroom I Suite 302 for students seeking a combination of studies. The Environmental Studies track is designed for students who

Wu, Shin-Tson

327

On-Line Selection of Discriminative Tracking Features  

E-Print Network [OSTI]

in lighting conditions. Tracking success/failure is highly correlated with our ability to distinguish object

Collins, Robert T.

328

Location-Tracking Applications ecent technological advances in wireless loca-  

E-Print Network [OSTI]

areas they have visited. #12;Location-Tracking Applications broker as part of their service contract

Gruteser, Marco

329

Original Article Clinician-Educator Tracks for Residents  

E-Print Network [OSTI]

, and graduate outcomes. Results: Common elements in the tracks are faculty mentor- ship, formal didactics

Yoo, S. J. Ben

330

P-odd, P-even, and T-odd asymmetries in true quaternary fission of nuclei  

SciTech Connect (OSTI)

The coefficients of P-odd, P-even, and T -odd asymmetries for a third and a fourth prescission particle emitted in the true quaternary fission of nuclei that was induced by polarized cold neutrons were studied on the basis of quantum-mechanical fission theory. By using non-evaporation (nonadiabatic) mechanisms of light-particle emission, these coefficients were compared with the analogous coefficients for prescission third particles emitted in the ternary fission of nuclei.

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

2013-04-15T23:59:59.000Z

331

A Review of Previous Research in Direct Energy Conversion Fission Reactors  

SciTech Connect (OSTI)

From the earliest days of power reactor development, direct energy conversion was an obvious choice to produce high efficiency electric power generation. Directly capturing the energy of the fission fragments produced during nuclear fission avoids the intermediate conversion to thermal energy and the efficiency limitations of classical thermodynamics. Efficiencies of more than 80% are possible, independent of operational temperature. Direct energy conversion fission reactors would possess a number of unique characteristics that would make them very attractive for commercial power generation. These reactors would be modular in design with integral power conversion and operate at low pressures and temperatures. They would operate at high efficiency and produce power well suited for long distance transmission. They would feature large safety margins and passively safe design. Ideally suited to production by advanced manufacturing techniques, direct energy conversion fission reactors could be produced more economically than conventional reactor designs. The history of direct energy conversion can be considered as dating back to 1913 when Moseleyl demonstrated that charged particle emission could be used to buildup a voltage. Soon after the successful operation of a nuclear reactor, E.P. Wigner suggested the use of fission fragments for direct energy conversion. Over a decade after Wigner's suggestion, the first theoretical treatment of the conversion of fission fragment kinetic energy into electrical potential appeared in the literature. Over the ten years that followed, a number of researchers investigated various aspects of fission fragment direct energy conversion. Experiments were performed that validated the basic physics of the concept, but a variety of technical challenges limited the efficiencies that were achieved. Most research in direct energy conversion ceased in the US by the late 1960s. Sporadic interest in the concept appears in the literature until this day, but there have been no recent significant programs to develop the technology.

DUONG,HENRY; POLANSKY,GARY F.; SANDERS,THOMAS L.; SIEGEL,MALCOLM D.

1999-09-22T23:59:59.000Z

332

DIRECT ENERGY CONVERSION (DEC) FISSION REACTORS - A U.S. NERI PROJECT  

SciTech Connect (OSTI)

The direct conversion of the electrical energy of charged fission fragments was examined early in the nuclear reactor era, and the first theoretical treatment appeared in the literature in 1957. Most of the experiments conducted during the next ten years to investigate fission fragment direct energy conversion (DEC) were for understanding the nature and control of the charged particles. These experiments verified fundamental physics and identified a number of specific problem areas, but also demonstrated a number of technical challenges that limited DEC performance. Because DEC was insufficient for practical applications, by the late 1960s most R&D ceased in the US. Sporadic interest in the concept appears in the literature until this day, but there have been no recent programs to develop the technology. This has changed with the Nuclear Energy Research Initiative that was funded by the U.S. Congress in 1999. Most of the previous concepts were based on a fission electric cell known as a triode, where a central cathode is coated with a thin layer of nuclear fuel. A fission fragment that leaves the cathode with high kinetic energy and a large positive charge is decelerated as it approaches the anode by a charge differential of several million volts, it then deposits its charge in the anode after its kinetic energy is exhausted. Large numbers of low energy electrons leave the cathode with each fission fragment; they are suppressed by negatively biased on grid wires or by magnetic fields. Other concepts include magnetic collimators and quasi-direct magnetohydrodynamic generation (steady flow or pulsed). We present the basic principles of DEC fission reactors, review the previous research, discuss problem areas in detail and identify technological developments of the last 30 years relevant to overcoming these obstacles. A prognosis for future development of direct energy conversion fission reactors will be presented.

D. BELLER; G. POLANSKY; ET AL

2000-11-01T23:59:59.000Z

333

Evaluation of fission product worth margins in PWR spent nuclear fuel burnup credit calculations.  

SciTech Connect (OSTI)

Current criticality safety calculations for the transportation of irradiated LWR fuel make the very conservative assumption that the fuel is fresh. This results in a very substantial overprediction of the actual k{sub eff} of the transportation casks; in certain cases, this decreases the amount of spent fuel which can be loaded in a cask, and increases the cost of transporting the spent fuel to the repository. Accounting for the change of reactivity due to fuel depletion is usually referred to as ''burnup credit.'' The US DOE is currently funding a program aimed at establishing an actinide only burnup credit methodology (in this case, the calculated reactivity takes into account the buildup or depletion of a limited number of actinides). This work is undergoing NRC review. While this methodology is being validated on a significant experimental basis, it implicitly relies on additional margins: in particular, the absorption of neutrons by certain actinides and by all fission products is not taken into account. This provides an important additional margin and helps guarantee that the methodology is conservative provided these neglected absorption are known with reasonable accuracy. This report establishes the accuracy of fission product absorption rate calculations: (1) the analysis of European fission product worth experiments demonstrates that fission product cross-sections available in the US provide very good predictions of fission product worth; (2) this is confirmed by a direct comparison of European and US cross section evaluations; (3) accuracy of Spent Nuclear Fuel (SNF) fission product content predictions is established in a recent ORNL report where several SNF isotopic assays are analyzed; and (4) these data are then combined to establish in a conservative manner the fraction of the predicted total fission product absorption which can be guaranteed based on available experimental data.

Blomquist, R.N.; Finck, P.J.; Jammes, C.; Stenberg, C.G.

1999-02-17T23:59:59.000Z

334

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

E-Print Network [OSTI]

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 of nuclear waste management. The goal of this paper is to set up the foundations of a microscopic model 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 fission of 239Pu(n,f). We compute the evolution of the least-energy fission pathway across multidimensional potential energy surfaces with up to five collective variables as a function of the nuclear temperature, and predict the evolution of both the inner and outer fission barriers as a function of the excitation energy of the compound nucleus. We show that the coupling to the continuum induced by the finite temperature is negligible in the range of neutron energies relevant to induced fission. We prove that the concept of quantum localization introduced recently can be extended to T>0, and we apply the method to compute the kinetic and interaction energy of fission fragments as a function of the temperature. While large uncertainties in theoretical modeling remain, we conclude that finite temperature nuclear density functional may provide a useful framework to obtain accurate predictions.

N. Schunck; D. Duke; H. Carr

2014-02-21T23:59:59.000Z

335

Study of dissipative dynamics in fission of hot nuclei using Langevin equation  

E-Print Network [OSTI]

The fission of highly excited compound nuclei formed in heavy ion induced fusion reactions has emerged as a topic of considerable interest in the recent years. Dissipative dynamical models based on the Langevin equation were developed and were applied successfully for fission dynamics of highly excited heavy nuclei. However, Wall Friction(WF), the standard version of nuclear friction when incorporated in the Langevin dynamical model was not able to reproduce simultaneously experimental data for both prescission neutron multiplicity and fission probability. Consequently, an empirical reduction in the strength of the wall friction was found necessary to reproduce the experimental numbers by many workers. Interestingly, a modification of the wall friction was proposed recently where the reduction was achieved microscopically. This modified version is known as the chaos weighted wall friction(CWWF) which takes into account non-integrability of single particle motion. The work in my thesis aims at using this strongly shape dependent version of friction (CWWF) in the Langevin dynamical model coupled with particle and gamma evaporation in order to verify to what extent it can account for the experimental data of fission of hot nuclei. The experimental data includes excitation functions of prescission neutron multiplicity, fission probability as well as evaporation residue cross-section of a number of nuclei. The importance of transients in nuclear fission is also discussed. The present endeavour is an effort to obtain a clear physical picture of nuclear dissipation which in turn will help in solving many open problems related to collective motion, and in particular, nuclear fission.

Gargi Chaudhuri

2004-11-01T23:59:59.000Z

336

Test of the adequacy of using smoothly joined parabolic segments to parametrize the multihumped fission barriers in actinides  

SciTech Connect (OSTI)

The adequacy of using smoothly joined parabolic segments to parametrize the multihumped fission barriers has been tested by examining its simultaneous consistency with the three relevant fission observables, namely, the near-barrier fission cross sections, isomeric half-lives, and the ground-state spontaneous fission half-lives of a wide variety of a total of 25 actinide nuclides. The penetrabilities through such multihumped fission barriers have been calculated in the Wentzel-Kramers-Brillouin approximation, and the various fission half-lives have been determined using the formalism given earlier by Nix and Walker. The results of our systematic analysis of these actinide nuclides suggest that such a parametrization is quite adequate at least for the even-even nuclei, as it reproduces satisfactorily their various observed fission characteristics. Major difficulties remain, however, for the odd mass and for the doubly odd nuclei where the calculated ground-state spontaneous fission half-lives are found to be several orders of magnitude larger than those measured. Possible reasons for such discrepancies are discussed. Fission branching ratios of the decay of the shape isomers in various actinide nuclides have also been calculated and are compared with their measured values.

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

1990-10-01T23:59:59.000Z

337

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

E-Print Network [OSTI]

of Con- trolled Nuclear Fusion, CONF-760975-P3, pages 1061more effective solution, nuclear fusion. Fission Energy Thethe development of nuclear fusion weapons, humankind has

Kramer, Kevin James

2010-01-01T23:59:59.000Z

338

DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000  

SciTech Connect (OSTI)

OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,1999 THRIUGH FEBRUARY 29,2000

LC BROWN

2000-02-29T23:59:59.000Z

339

DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD OCTOBER 1,2001 THROUGH DECEMBER 31,2001  

SciTech Connect (OSTI)

OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD OCTOBER 1,2001 THROUGH DECEMBER 31,2001

L.C. BROWN

2001-12-31T23:59:59.000Z

340

DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,2000 THROUGH FEBRUARY 28,2001  

SciTech Connect (OSTI)

OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD DECEMBER 1,2000 THROUGH FEBRUARY 28,2001

L.C. BROWN

2000-02-28T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD AUGUST 15,2000 THROUGH SEPTEMBER 30,2001  

SciTech Connect (OSTI)

OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD AUGUST 15,2000 THROUGH SEPTEMBER 30,2001

L.C. BROWN

2002-02-01T23:59:59.000Z

342

DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD OCTOBER 1, 2001 THROUGH DECEMBER 31, 2002  

SciTech Connect (OSTI)

OAK-B135 DIRECT ENERGY CONVERSION FISSION REACTOR ANNUAL REPORT FOR THE PERIOD OCTOBER 1, 2001 THROUGH DECEMBER 31, 2002

L.C. BROWN

2003-04-07T23:59:59.000Z

343

Singlet-Fission Sensitizers for Ultra-High Efficiency Excitonic Solar Cells: 15 August 2005 - 14 October 2008  

SciTech Connect (OSTI)

We have considered the potential benefits offered by using singlet fission sensitizers in photovoltaic cells and identified two key issues involved in the search for such sensitizers.

Michl, J.

2008-12-01T23:59:59.000Z

344

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

E-Print Network [OSTI]

DT Deuterium-Tritium DU Depleted Uranium FIMA Fission ofengine loaded with depleted uranium. In Proc. PHYSOR 2010,fuel layer comprised of depleted uranium contained in

Kramer, Kevin James

2010-01-01T23:59:59.000Z

345

CDC's National Environmental Public Health Tracking Network VERMONT Keeping Track, Promoting Health  

E-Print Network [OSTI]

exposures such as air pollution and drinking water contaminants. The health department began receiving monitoring data show that this county also has the most days per year of air pollution from fine particulateCS225774_O CDC's National Environmental Public Health Tracking Network VERMONT Keeping Track

346

Tracking Graphics State forTracking Graphics State for Network RenderingNetwork Rendering  

E-Print Network [OSTI]

Tracking Graphics State forTracking Graphics State for Network RenderingNetwork Rendering Ian Buck 2000 Distributed GraphicsDistributed Graphics Application Application Application Renderer Renderer Renderer Network How to manage distributed graphics applications, renderers, and displays? #12;HWWS 2000

Pratt, Vaughan

347

Neutron capture studies: 1, Multiple capture reactions and implications for calculated beta-delayed fission rates: 2, The nuclear level structure of 238Np  

SciTech Connect (OSTI)

Astrophysical r-process calculations of transbismuth elements are of interest because certain actinide pairs can be treated as chronometers in determining the duration of nucleosynthesis. For one such calculation where a particularly long galactic age was derived, 21 + 2 - 4 Gyr, we present evidence that the effect of beta-delayed fission appears to be seriously overestimated in uranium decay chains with A = 252 to 257. With this conclusion, it follows that this estimate of the galactic age must be considered more uncertain than if the calculated rates of beta-delayed fission were found to be acceptable. The nuclear level structure of 238Np has been investigated using the 237Np(n,..gamma..)238Np reaction and the alpha decay of 242mAm as experimental probes. Having established a level scheme for 238Np that includes 47 excited levels and 93 secondary transitions, we find a high degree of correspondence between the experimental band structure and that of a semi-empirical model developed to predict excitations in odd-odd deformed nuclei. 35 refs., 4 figs., 3 tabs.

Hoff, R.W.

1988-02-19T23:59:59.000Z

348

Fission-product-release signatures for LWR fuel rods failed during PCM and RIA transients  

SciTech Connect (OSTI)

This paper discusses fission product release from light-water-reactor-type fuel rods to the coolant loop during design basis accident tests. One of the tests was a power-cooling-mismatch test in which a single fuel rod was operated in film boiling beyond failure. Other tests discussed include reactivity initiated accident (RIA) tests, in which the fuel rods failed as a result of power bursts that produced radial-average peak fuel enthalpies ranging from 250 to 350 cal/g. One of the RIA tests used two previously irradiated fuel rods. On-line gamma spectroscopic measurements of short-lived fission products, and important aspects of fission product behavior observed during the tests, are discussed. Time-dependent release fractions for short-lived fission products are compared with release fractions suggested by: the Reactor Safety Study; NRC Regulatory Guides; and measurements from the Three Mile Island accident. Iodine behavior observed during the tests is discussed, and fuel powdering is identified as a source of particulate fission product activity, the latter of which is neglected for most accident analyses.

Osetek, D.J.; King, J.J.; Croucher, D.W.

1981-01-01T23:59:59.000Z

349

Fission matrix-based Monte Carlo criticality analysis of fuel storage pools  

SciTech Connect (OSTI)

Standard Monte Carlo transport procedures experience difficulties in solving criticality problems in fuel storage pools. Because of the strong neutron absorption between fuel assemblies, source convergence can be very slow, leading to incorrect estimates of the eigenvalue and the eigenfunction. This study examines an alternative fission matrix-based Monte Carlo transport method that takes advantage of the geometry of a storage pool to overcome this difficulty. The method uses Monte Carlo transport to build (essentially) a fission matrix, which is then used to calculate the criticality and the critical flux. This method was tested using a test code on a simple problem containing 8 assemblies in a square pool. The standard Monte Carlo method gave the expected eigenfunction in 5 cases out of 10, while the fission matrix method gave the expected eigenfunction in all 10 cases. In addition, the fission matrix method provides an estimate of the error in the eigenvalue and the eigenfunction, and it allows the user to control this error by running an adequate number of cycles. Because of these advantages, the fission matrix method yields a higher confidence in the results than standard Monte Carlo. We also discuss potential improvements of the method, including the potential for variance reduction techniques. (authors)

Farlotti, M. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Ecole Polytechnique, Palaiseau, F 91128 (France); Larsen, E. W. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States)

2013-07-01T23:59:59.000Z

350

Fission Yield Measurements from Highly Enriched Uranium Irradiated Inside a Boron Carbide Capsule  

SciTech Connect (OSTI)

A boron carbide capsule was previously designed and tested by Pacific Northwest National Laboratory (PNNL) and Washington State University (WSU) for spectral-tailoring in mixed spectrum reactors. The presented work used this B4C capsule to create a fission product sample from the irradiation of highly enriched uranium (HEU) with a fast fission neutron spectrum. An HEU foil was irradiated inside of the capsule in WSUs 1 MW TRIGA reactor at full power for 200 min to produce 5.8 1013 fissions. After three days of cooling, the sample was shipped to PNNL for radiochemical separations and analysis by gamma and beta spectroscopy. Fission yields for products were calculated from the radiometric measurements and compared to measurements from thermal neutron induced fission (analyzed in parallel with the non-thermal sample at PNNL) and published evaluated fast-pooled and thermal nuclear data. Reactor dosimetry measurements were also completed to fully characterize the neutron spectrum and total fluence of the irradiation.

Metz, Lori A.; Friese, Judah I.; Finn, Erin C.; Greenwood, Lawrence R.; Kephart, Rosara F.; Hines, Corey C.; King, Matthew D.; Henry, Kelley; Wall, Donald E.

2013-05-01T23:59:59.000Z

351

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

SciTech Connect (OSTI)

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.

L.C. BROWN

2002-03-31T23:59:59.000Z

352

New features in the stability and fission decay of superheavy Thorium isotopes  

E-Print Network [OSTI]

Superheavy isotopes are highly neutron rich nuclei in the vicinity of neutron drip-line, stabilized by shell effect against the instability due to repulsive component of nuclear force, analogous to superheavy elements similarly stabilized against Coulomb instability. Here we discuss the stability and fission decay properties of such nuclei in the $^{254}$Th region and show that they are stable against $\\alpha$ and fission decay and have $\\beta$-decay life time of several tens of seconds. In particular, the $^{254}$Th nucleus has a low fission barrier and unusally large barrier width. This makes it an ideal thermally fissile nucleus, if formed by means of a thermal neutron, like other known nuclei such as $^{233}$U, $^{235}$U, $^{239}$Pu in this actinide region. It shows a new mode of fast fission decay, which may be termed as multifragmentation fission, in which in addition to two heavy fragments large number of scission neutrons are simultaneously produced. Its likely synthesis during the r-process nucleosynthesis will have important bearing on steller evolution, and here in the laboratory, it has great potential in energy production.

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

2006-04-12T23:59:59.000Z

353

Method of Fission Product Beta Spectra Measurements for Predicting Reactor Anti-neutrino Emission  

E-Print Network [OSTI]

The nuclear fission process that occurs in the core of nuclear reactors results in unstable, neutron rich fission products that subsequently beta decay and emit electron anti-neutrinos. These reactor neutrinos have served neutrino physics research from the initial discovery of the neutrino to current precision measurements of neutrino mixing angles. The prediction of the absolute flux and energy spectrum of the emitted reactor neutrinos hinges upon a series of seminal papers based on measurements performed in the 1970s and 1980s. The steadily improving reactor neutrino measurement techniques and recent re-considerations of the agreement between the predicted and observed reactor neutrino flux motivates revisiting the underlying beta spectra measurements. A method is proposed to use an accelerator proton beam delivered to an engineered target to yield a neutron field tailored to reproduce the neutron energy spectrum present in the core of an operating nuclear reactor. Foils of the primary reactor fissionable isotopes placed in this tailored neutron flux will ultimately emit beta particles from the resultant fission products. Measurement of these beta particles in a time projection chamber with a perpendicular magnetic field provides a distinctive set of systematic considerations for comparison to the original seminal beta spectra measurements. Ancillary measurements such as gamma-ray emission and post-irradiation radiochemical analysis will further constrain the absolute normalization of beta emissions per fission. The requirements for unfolding the beta spectra measured with this method into a predicted reactor neutrino spectrum are explored.

D. M. Asner; K. Burns; L. W. Campbell; B. Greenfield; M. S. Kos; J. L. Orrell; M. Schram; B. VanDevender; 1 L. S. Wood; D. W. Wootan

2014-03-01T23:59:59.000Z

354

Insights On The Thermal History Of The Valles Caldera, New Mexico...  

Open Energy Info (EERE)

Insights On The Thermal History Of The Valles Caldera, New Mexico- Evidence From Zircon Fission-Track Analysis Jump to: navigation, search OpenEI Reference LibraryAdd to library...

355

Automatically processed alpha-track radon monitor  

DOE Patents [OSTI]

An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided.

Langner, G.H. Jr.

1993-01-12T23:59:59.000Z

356

Magnetic Field Generation in Planets and Satellites by Natural Nuclear Fission Reactors  

E-Print Network [OSTI]

One of the most fundamental problems in physics has been to understand the nature of the mechanism that generates the geomagnetic field and the magnetic fields of other planets and satellites. For decades, the dynamo mechanism, thought to be responsible for generating the geomagnetic field and other planetary magnetic fields, has been ascribed to convection in each planet's iron-alloy core. Recently, I described the problems inherent in Earth-core convection and proposed instead that the geomagnetic field is produced by a dynamo mechanism involving convection, not in the fluid core, but in the electrically conductive, fluid, fission-product sub-shell of a natural nuclear fission reactor at the center of the Earth, called the georeactor. Here I set forth in detail the commonality in the Solar System of the matter like that of the inside of the Earth, which is my basis for generalizing the concept of planetary magnetic field generation by natural planetocentric nuclear fission reactors.

J. Marvin Herndon

2007-09-27T23:59:59.000Z

357

Delayed neutron noise characteristics of an in-pile fission product loop  

SciTech Connect (OSTI)

This paper reports on delayed neutron noise measurements carried out in an in-pile sodium loop, the Fission Product Loop 2 (FPL-2), installed on the Toshiba Training Reactor I. To clarify the characteristics and origin of delayed neutron count rate noise, a noise propagation mechanism was identified using a multivariate autoregressive model. The results show that a simulated fuel failure in the FPL-2, with recoil as the principal fission product release phenomena, produces a white spectrum of delayed neutron count rate noise. It was also found that the loop temperature fluctuation strongly affects the delayed neutron count rate noise at temperatures below 300{degrees} C, through the deposition of fission products on the surface of structures.

Tamaoki, T. (Toshiba Corp., Nuclear Engineering Lab., 8 Shin-Sugita, Isogo-ku, Yokohama 235 (JP)); Sakai, T.; Endo, H. (Toshiba Corp., Isogo Engineering Center, 8 Shin-Sugita, Isogo-ku, Yokohama 235 (JP)); Haga, K. (Power Reactor and Nuclear Fuel Development Corp., O-aral Engineering Center, 4002 Narita, O-araimachi, Ibaraki-ken 311-13 (JP)); Takahashi, R. (Tokyo Inst. of Technology, Dept. of Mechanical Engineering, Ookayama, Meguro-ku, Tokyo 152 (JP))

1992-07-01T23:59:59.000Z

358

Study of dissipative dynamics in fission of hot nuclei using Langevin equation  

E-Print Network [OSTI]

The fission of highly excited compound nuclei formed in heavy ion induced fusion reactions has emerged as a topic of considerable interest in the recent years. Dissipative dynamical models based on the Langevin equation were developed and were applied successfully for fission dynamics of highly excited heavy nuclei. However, Wall Friction(WF), the standard version of nuclear friction when incorporated in the Langevin dynamical model was not able to reproduce simultaneously experimental data for both prescission neutron multiplicity and fission probability. Consequently, an empirical reduction in the strength of the wall friction was found necessary to reproduce the experimental numbers by many workers. Interestingly, a modification of the wall friction was proposed recently where the reduction was achieved microscopically. This modified version is known as the chaos weighted wall friction(CWWF) which takes into account non-integrability of single particle motion. The work in my thesis aims at using this stron...

Chaudhuri, G

2004-01-01T23:59:59.000Z

359

Tracking Provenance in ORNL's Flexible Research Platforms  

SciTech Connect (OSTI)

Provenance is dened as information about the origin of objects, a concept that applies to both physical and digital objects and often overlaps both. The use of provenance in systems designed for research is an important but forgotten feature. Provenance allows for proper and exact tracking of information, its use, its lineage, its derivations and other metadata that are important for correctly adhering to the scien- tic method. In our project's prescribed use of provenance, researchers can determine detailed information about the use of sensor data in their experiments on ORNL's Flexible Research Platforms (FRPs). Our project's provenance system, Provenance Data Management System (ProvDMS), tracks information starting with the creation of information by an FRP sensor. The system determines station information, sensor information, and sensor channel information. The system allows researchers to derive generations of experiments from the sensor data and tracks their hierarchical flow. Key points can be seen in the history of the information as part of the information's workflow. The concept of provenance and its usage in science is relatively new and while used in other cases around the world, our project's provenance diers in a key area. To keep track of provenance, most systems must be designed or redesigned around the new provenance system. Our system is designed as a cohesive but sepa- rate entity and allows for researchers to continue using their own methods of analysis without being constrained in their ways in order to track the provenance. We have designed ProvDMS using a lightweight provenance library, Core Provenance Library (CPL) v.6 In addition to keeping track of sensor data experiments and its provenance, ProvDMS also provides a web-enabled visualization of the inheritance.

Hensley, Zachary P [ORNL; Sanyal, Jibonananda [ORNL; New, Joshua Ryan [ORNL

2013-08-01T23:59:59.000Z

360

Chemical tracking at the Rocky Flats Plant  

SciTech Connect (OSTI)

EG&G Rocky Flats, Inc., has developed a chemical tracking system to support compliance with the Emergency Planning and community Right-to-Know Act (EPCRA) at the Rocky Flats Plant. This system, referred to as the EPCRA Chemical Control system (ECCS), uses bar code technology to uniquely identify and track the receipt, distribution, and use of chemicals. Chemical inventories are conducted using hand-held electronic scanners to update a site wide chemical database on a VAX 6000 computer. Information from the ECCS supports preparation of the EPCRA Tier II and Form R reports on chemical storage and use.

Costain, D.B.

1994-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

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

SciTech Connect (OSTI)

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

J M Harp; P D Demkowicz; S A Ploger

2012-10-01T23:59:59.000Z

362

Fission-Fusion: A new reaction mechanism for nuclear astrophysics based on laser-ion acceleration  

SciTech Connect (OSTI)

We propose to produce neutron-rich nuclei in the range of the astrophysical r-process around the waiting point N = 126 by fissioning a dense laser-accelerated thorium ion bunch in a thorium target (covered by a CH{sub 2} layer), where the light fission fragments of the beam fuse with the light fission fragments of the target. Via the 'hole-boring' mode of laser Radiation Pressure Acceleration using a high-intensity, short pulse laser, very efficiently bunches of {sup 232}Th with solid-state density can be generated from a Th target and a deuterated CD{sub 2} foil, both forming the production target assembly. Laser-accelerated Th ions with about 7 MeV/u will pass through a thin CH{sub 2} layer placed in front of a thicker second Th foil (both forming the reaction target) closely behind the production target and disintegrate into light and heavy fission fragments. In addition, light ions (d,C) from the CD{sub 2} layer of the production target will be accelerated as well, inducing the fission process of {sup 232}Th also in the second Th layer. The laser-accelerated ion bunches with solid-state density, which are about 10{sup 14} times more dense than classically accelerated ion bunches, allow for a high probability that generated fission products can fuse again. The high ion beam density may lead to a strong collective modification of the stopping power, leading to significant range and thus yield enhancement. Using a high-intensity laser as envisaged for the ELI-Nuclear Physics project in Bucharest (ELI-NP), order-of-magnitude estimates promise a fusion yield of about 10{sup 3} ions per laser pulse in the mass range of A = 180-190, thus enabling to approach the r-process waiting point at N = 126.

Thirolf, P. G.; Gross, M.; Allinger, K.; Bin, J.; Henig, A.; Kiefer, D. [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-85748 Garching (Germany); Habs, D. [Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, D-85748 Garching (Germany); Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany); Ma, W.; Schreiber, J. [Max-Planck-Institut fuer Quantenoptik, D-85748 Garching (Germany)

2011-10-28T23:59:59.000Z

363

True ternary fission, the collinear cluster tripartition (CCT) of {sup 252}Cf  

SciTech Connect (OSTI)

In systematic work over the last decade (see Pyatkov et al. [12] and refs therein), the ternary fission decay of heavy nuclei, in {sup 235}U(n,fff) and {sup 252}Cf(sf) has been studied in a collinear geometry. The name used for this process is (CCT), with three fragments of similar size in a collinear decay, it is the true ternary fission. This decay has been observed in spontaneous fission as well as in a neutron induced reaction. The measurements are based on different experimental set-ups, with binary coincidences containing TOF and energy determinations. With two detector telescopes placed at 180 Degree-Sign , the measurements of masses and energies of each of the registered two fragments, give complete kinematic solutions. Thus the missing mass events in binary coincidences can be determined, these events are obtained by blocking one of the lighter fragments on a structure in front of the detectors. The relatively high yield of CCT (more than 10{sup -3} per binary fission) is explained. It is due to the favourable Q-values (more positive than for binary) and the large phase space of the ternary CCT-decay, dominated by three (magic) clusters: e.g. isotopes of Sn, Ca and Ni, {sup 132}Sn+{sup 50}Ca+{sup 70}Ni. It is shown that the collinear (prolate) geometry has the favoured potential energy relative to the oblate shapes. The ternary fission is considered to be a sequential process. With this assumption the kinetic energies of the fragments have been calculated by Vijay et al.. The third fragments have very low kinetic energies (below 20 MeV) and have thus escaped their detection in previous work on 'ternary fission', where in addition an oblate shape and a triangle for the momentum vectors have been assumed.

Oertzen, W. von; Pyatkov, Y. V.; Kamanin, D. [Helmholtz Zentrum, D14109 Berlin (Germany); Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Moscow region (Russian Federation); Flerov Laboratory of Nuclear Reactions, JINR, Dubna, Moscow region (Russian Federation) and Helmholtz Zentrum, D14109 Berlin (Germany)

2012-10-20T23:59:59.000Z

364

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

E-Print Network [OSTI]

of a Hybrid Fusion-Fission Nuclear Energy System. Thesis.hybrid fusion-fission Laser Inertial Fusion-based Energy (LIFE) systems.Hybrid LIFE Engines Laser Inertial Fusion-based Energy (LIFE) systems

Powers, Jeffrey

2011-01-01T23:59:59.000Z

365

November 9, 2003 21:47 WSPC/Trim Size: 9in x 6in for Proceedings royer-nanuf03 FISSION BARRIERS  

E-Print Network [OSTI]

Institute of Physics and Nuclear Engineering, P.O. Box MG-6, RO-76900, Bucharest, Romania E-mail: rgherg-fission of heavy systems and fragmentation have renewed interest in investigating the fusion-like fission valley

Paris-Sud XI, Université de

366

Probabilities for the emission of light particles and their energy and angular distributions for true quaternary nuclear fission  

SciTech Connect (OSTI)

On the basis of quantum-mechanical fission theory, the features of true quaternary nuclear fission are studied by treating this fission process as a sequence of three processes following one another in the course of time. The first two processes are the escape of the first and then the second of the two light particles emitted from the neck of a fissioning nucleus because of a nonadiabatic character of the collective deformation motion of this nucleus. Finally, the third process is the separation of the fissioning nucleus into two rather heavy fission fragments. The differences that arise in the emission probabilities and in the angular and energy distributions upon going over from the first emitted to the second emitted prescission third and fourth particles are analyzed by invoking experimental data on the spontaneous and thermalneutron-induced fission of nuclei, and it is shown that these differences are caused by the changes both in the geometric configuration of the fissioning nucleus and in the shell structure of its neck after the first prescission particle is emitted from it.

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

2013-01-15T23:59:59.000Z

367

Relative yields of U-235 fission products measured in a high level radioactive sludge at Savannah River Site  

SciTech Connect (OSTI)

This paper presents measurements of the concentrations of 42 of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at Savannah River Site. The 42 fision products make up 98% of the waste sludge. We used inductively coupled plasma-mass spectroscopy for the analysis. The relative yields for most of the fission products are in complete agreement with the known relative yields for the beta decay chains of the two asymmetric branches of the slow neutron fission of U-235. Disagreements can be reconciled based on the chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses. This paper presents measurements of the concentrations of 42 (98%) of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at the Savannah River Site. We analyzed the sludge with inductively coupled plasma-mass spectroscopy. The relative yields for most of the fission products agree completely with the known relative vields for the beta decay chains of the two asymmetric: branches of the slow neutron fission of U-235. The chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses explain the differences in the measured and calculated results.

Bibler, N.E.; Coleman, C.J. [Westinghouse Savannah River Co., Aiken, SC (United States); Kinard, W.F. [Charleston Coll., SC (United States). Dept. of Chemistry

1992-10-01T23:59:59.000Z

368

Relative yields of U-235 fission products measured in a high level radioactive sludge at Savannah River Site  

SciTech Connect (OSTI)

This paper presents measurements of the concentrations of 42 of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at Savannah River Site. The 42 fision products make up 98% of the waste sludge. We used inductively coupled plasma-mass spectroscopy for the analysis. The relative yields for most of the fission products are in complete agreement with the known relative yields for the beta decay chains of the two asymmetric branches of the slow neutron fission of U-235. Disagreements can be reconciled based on the chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses. This paper presents measurements of the concentrations of 42 (98%) of the long-lived U-235 fission products in a high-level radioactive waste sludge stored at the Savannah River Site. We analyzed the sludge with inductively coupled plasma-mass spectroscopy. The relative yields for most of the fission products agree completely with the known relative vields for the beta decay chains of the two asymmetric: branches of the slow neutron fission of U-235. The chemistry of the fission products in the caustic waste sludges, the neutron fluences in SRS reactors, or interferences in the ICP-MS analyses explain the differences in the measured and calculated results.

Bibler, N.E.; Coleman, C.J. (Westinghouse Savannah River Co., Aiken, SC (United States)); Kinard, W.F. (Charleston Coll., SC (United States). Dept. of Chemistry)

1992-01-01T23:59:59.000Z

369

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

E-Print Network [OSTI]

Physics - Particle and Nuclear Physics | Theory of Nuclear Fission © Springer is part of Springer Science+Business Media Theory of Nuclear Fission A Textbook Series: Lecture Notes in Physics, Vol. 838 v arious aspects of the nuclear f ission phenomenon discov ered by Hahn, Strassmann and Meitner

Pomorski, Krzysztof

370

The Fission Yeast Copper-sensing Transcription Factor Cuf1 Regulates the Copper Transporter Gene Expression through an  

E-Print Network [OSTI]

The Fission Yeast Copper-sensing Transcription Factor Cuf1 Regulates the Copper Transporter Gene of copper transport is essential for copper homeostasis and growth in yeast. Analysis of regulatory regions in the promoter of the ctr4 copper transporter gene in fission yeast Schizosaccharomyces pombe re- veals

Labbé, Simon

371

Measurement of Prompt Fission Neutron Spectrum Using a Gamma Tagging Method E. Blain, A. Daskalakis, Y. Danon  

E-Print Network [OSTI]

uncertainties in these values can have significant impact on the uncertainty associated with reactor criticality correspond to up to a 4% uncertainty on keff for various systems including both fast and light water systems fission chamber which uses the energy deposited by fission fragments in a fill gas to determine

Danon, Yaron

372

Critical temperature for the nuclear liquid-gas phase transition (from multifragmentation and fission)  

E-Print Network [OSTI]

Critical temperature Tc for the nuclear liquid-gas phase transition is stimated both from the multifragmentation and fission data. In the first case,the critical temperature is obtained by analysis of the IMF yields in p(8.1 GeV)+Au collisions within the statistical model of multifragmentation (SMM). In the second case, the experimental fission probability for excited 188Os is compared with the calculated one with Tc as a free parameter. It is concluded for both cases that the critical temperature is higher than 16 MeV.

V. A. Karnaukhov; H. Oeschler; A. Budzanowski; S. P. Avdeyev; A. S. Botvina; E. A. Cherepanov; W. Karcz; V. V. Kirakosyan; P. A. Rukoyatkin; I. Skwirczynska; E. Norbeck

2008-01-29T23:59:59.000Z

373

The effect of. beta. -delayed fission on the production of r-process chronometers  

SciTech Connect (OSTI)

The nuclear physics required for calculating the production ratios for the chronometric pairs {sup 235}U/{sup 232}Th and {sup 238}U/{sup 232}Th in the astrophysical r-process is considered in some detail. In particular, we calculate the nuclear structure of neutron-rich heavy elements to investigate the effects of beta-delayed fission and beta-delayed neutron emission during the beta decay from the r-process path to the actinide region. We find that previous estimates of the effects of beta-delayed fission on the production of these pairs has probably been overestimated. 11 refs., 1 fig.

Howard, W.M.; Meyer, B.S.

1989-08-30T23:59:59.000Z

374

Proposal for ENDF formats that describe emission of post-fission beta-delayed photons  

SciTech Connect (OSTI)

Fission of heavy nuclides is accompanied by the birth of neutron rich fragment nuclei born in highly excited states. Following emission of prompt neutrons and {gamma}-rays, these fragments are typically left with atomic numbers that are 3-4 units smaller than stable nuclei with the same mass number. As these nuclides undergo {beta} decay to reach stability, a large number of {gamma}-rays are emitted. Figure 1 illustrates some of the processes leading to emission of {beta} delayed photons. A variety of applications (most notably those concerned with the detection and identification of clandestine fissile material) would benefit from a clear description of the spectral and temporal evolution of these {gamma}-rays. This proposal describes formats for representing emission of delayed photons and is based on the analysis presented in. At the present time, no single evaluated data set exists that directly provides for the temporal evolution of {gamma} rays from the decay of the fission products. However, evaluated data sets containing all of the physical parameters required for such calculations have been prepared. These include estimates of the independent and cumulative fission yields of all fission products, branching ratios in the decay of ground and isomeric states, lifetimes of these states, and the spectra of {gamma} rays emitted in their decay. Sizeable uncertainties and possibly significant errors are likely present concerning the shortest-lived fission products. However, the high-energy {gamma}-ray spectra generated from some of these data sets have been shown to be in reasonable agreement with initial experiments designed specifically to test them under conditions likely to be of interest to interrogation of sea-going cargo containers. For clarity we emphasize that the relationship between delayed neutron emission and delayed photon emission is tenuous. Only a small fraction of fission fragments - typically those characterized by large decay Q values - undergo {beta}{sup -}n emission. However, essentially all fission fragment decays result in the emission of a few photons. Also, it would be impractical to accurately specify and measure energies of delayed neutrons. By contrast, most fission fragments have decay spectra known to sub-keV accuracy that are readily resolved with inexpensive field HpGe detectors.

Brown, D; Pruet, J; Hedstrom, G; Hall, J; Descalle, M

2004-09-15T23:59:59.000Z

375

From ground state to fission fragments: A complex, multi-dimensional multi-path problem  

SciTech Connect (OSTI)

Experimental results on the fission properties of nuclei close to {sup 264}Fm show sudden and large changes with a change of only one or two neutrons or protons. The nucleus {sup 258}Fm, for instance, undergoes symmetric fission with a half-life of about 0.4 ms and a kinetic-energy distribution peaked at about 235 MeV whereas {sup 256}Fm undergoes asymmetric fission with a half-life of about 3 h and a kinetic-energy distribution peaked at about 200 MeV. Qualitatively, these sudden changes have been postulated to be due to the emergence of fragment shells in symmetric-fission products close to {sup 132}Sn. Here we present a quantitative calculation that shows where high-kinetic-energy symmetric fusion occurs and why it is associated with a sudden and large decrease in fission half-lives. We base our study on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. We use the three-quadratic-surface parameterization to generate the shapes for which the potential-energy surfaces are calculated. The use of this parameterization and the use of the finite-range macroscopic model allows for the study of two touching spheres and similar shapes. Since these shapes are thought to correspond to the scission shapes for the high-kinetic-energy events it is of crucial importance that a continuous sequence of shapes leading from the nuclear ground state to these configurations can be studied within the framework of the model. We present the results of the calculations in terms of potential-energy surfaces and fission half-lives for heavy even nuclei. The surfaces are displayed in the form of contour diagrams as functions of two moments of the shape. They clearly show the appearance of a second fission valley, which leads to scission configurations close to tow touching spheres, for fissioning systems in the vicinity of {sup 264}Fm.

Moeller, P. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)); Nix, J.R. (Los Alamos National Lab., NM (United States)); Swiatecki, W.J. (Lawrence Berkeley Lab., CA (United States))

1992-01-01T23:59:59.000Z

376

From ground state to fission fragments: A complex, multi-dimensional multi-path problem  

SciTech Connect (OSTI)

Experimental results on the fission properties of nuclei close to {sup 264}Fm show sudden and large changes with a change of only one or two neutrons or protons. The nucleus {sup 258}Fm, for instance, undergoes symmetric fission with a half-life of about 0.4 ms and a kinetic-energy distribution peaked at about 235 MeV whereas {sup 256}Fm undergoes asymmetric fission with a half-life of about 3 h and a kinetic-energy distribution peaked at about 200 MeV. Qualitatively, these sudden changes have been postulated to be due to the emergence of fragment shells in symmetric-fission products close to {sup 132}Sn. Here we present a quantitative calculation that shows where high-kinetic-energy symmetric fusion occurs and why it is associated with a sudden and large decrease in fission half-lives. We base our study on calculations of potential-energy surfaces in the macroscopic-microscopic model and a semi-empirical model for the nuclear inertia. We use the three-quadratic-surface parameterization to generate the shapes for which the potential-energy surfaces are calculated. The use of this parameterization and the use of the finite-range macroscopic model allows for the study of two touching spheres and similar shapes. Since these shapes are thought to correspond to the scission shapes for the high-kinetic-energy events it is of crucial importance that a continuous sequence of shapes leading from the nuclear ground state to these configurations can be studied within the framework of the model. We present the results of the calculations in terms of potential-energy surfaces and fission half-lives for heavy even nuclei. The surfaces are displayed in the form of contour diagrams as functions of two moments of the shape. They clearly show the appearance of a second fission valley, which leads to scission configurations close to tow touching spheres, for fissioning systems in the vicinity of {sup 264}Fm.

Moeller, P. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan); Nix, J.R. [Los Alamos National Lab., NM (United States); Swiatecki, W.J. [Lawrence Berkeley Lab., CA (United States)

1992-03-01T23:59:59.000Z

377

Target and method for the production of fission product molybdenum-99  

DOE Patents [OSTI]

A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm/sup 2/ of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99. 2 figs.

Vandegrift, G.F.; Vissers, D.R.; Marshall, S.L.; Varma, R.

1987-10-26T23:59:59.000Z

378

He-jet system to study short-lived fission-product nuclei at LAMPF  

SciTech Connect (OSTI)

Experiments have been performed at LAMPF which demonstrate the feasibility of utilizing a He-jet system to transport fission products to an on-line mass separator from a target chamber mounted in the 800-MeV, >600..mu..A main proton beam. Activities of essentially all elements produced are transported with about 60% absolute efficiency, both for fission reactions and spallation reactions. Transport times are short enough to allow study of activities with half-lives as short as 300 ms. Technical features and scientific possibilities of the system are presented.

Talbert, W.L. Jr.; Bunker, M.E.; Starner, J.W.

1983-01-01T23:59:59.000Z

379

DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD JULY 1, 2002 THROUGH SEPTEMBER 30, 2002  

SciTech Connect (OSTI)

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.

L.C. BROWN

2002-09-30T23:59:59.000Z

380

DIRECT ENERGY CONVERSION FISSION REACTOR FOR THE PERIOD APRIL 1, 2002 THROUGH JUNE 30, 2002  

SciTech Connect (OSTI)

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.

L.C. BROWN

2002-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Interplay between compound and fragments aspects of nuclear fission and heavy-ion reaction  

SciTech Connect (OSTI)

The scission point in nuclear fission plays a special role where one-body system changes to two-body system. Inverse of this situation is realized in heavy-ion fusion reaction where two-body system changes to one body system. Among several peculiar phenomena expected to occur during this change, we focus our attention to the behavior of compound and fragments shell effects. Some aspects of the interplay between compound and fragments shell effect are discussed related to the topics of the fission valleys in the potential energy surface of actinide nuclei and the fusion-like trajectory found in the cold fusion reaction leading to superheavy nuclei.

Moller, Peter [Los Alamos National Laboratory; Iwamoto, A [JAPAN; Ichikawa, I [JAPAN

2010-09-10T23:59:59.000Z

382

New fission fragment distributions and r-process origin of the rare-earth elements  

E-Print Network [OSTI]

Neutron star (NS) merger ejecta offer a viable site for the production of heavy r-process elements with nuclear mass numbers A > 140. The crucial role of fission recycling is responsible for the robustness of this site against many astrophysical uncertainties, but calculations sensitively depend on nuclear physics. In particular the fission fragment yields determine the creation of 110 rare-earth peak that is nicely compatible with the abundance patterns in the Sun and metal-poor stars. This new finding further strengthens the case of NS mergers as possible dominant origin of r-nuclei with A > 140.

S. Goriely; J. -L. Sida; J. -F. Lemaitre; S. Panebianco; N. Dubray; S. Hilaire; A. Bauswein; H. -Thomas Janka

2013-11-22T23:59:59.000Z

383

Target and method for the production of fission product molybdenum-99  

DOE Patents [OSTI]

A target for the reduction of fission product Mo-99 is prepared from uranium of low U-235 enrichment by coating a structural support member with a preparatory coating of a substantially oxide-free substrate metal. Uranium metal is electrodeposited from a molten halide electrolytic bath onto a substrate metal. The electrodeposition is performed at a predetermined direct current rate or by using pulsed plating techniques which permit relaxation of accumulated uranium ion concentrations within the melt. Layers of as much as to 600 mg/cm.sup.2 of uranium can be prepared to provide a sufficient density to produce acceptable concentrations of fission product Mo-99.

Vandegrift, George F. (Bolingbrook, IL); Vissers, Donald R. (Naperville, IL); Marshall, Simon L. (Woodridge, IL); Varma, Ravi (Hinsdale, IL)

1989-01-01T23:59:59.000Z

384

Fission-barrier parameters of the compound nuclei /sup 245/Cm, /sup 247/Cm, and /sup 249/Cm  

SciTech Connect (OSTI)

The cross section for fission of /sup 248/Cm by neutrons has been measured in the energy interval 0.3< or =E/sub n/< or =5.5 MeV. The measurements were made by the time-of-flight method with use of an underground nuclear explosion as a pulsed neutron source. From the experimental data for the compound nuclei /sup 245/Cm, /sup 247/Cm, and /sup 249/Cm we have evaluated the following characteristics of the fission probability: the inner barrier height E/sup A//sub f/, the curvature parameter h..omega../sub A/ and the ratio of the average neutron and fission widths. Some features of the fission probability curves obtained are discussed, and also the question of the applicability of the systematics for prediction of fission characteristics of heavy nuclei with neutron number N>152.

Fomushkin, E.F.; Novoselov, G.F.; Vinogradov, Y.I.; Gavrilov, V.V.

1982-09-01T23:59:59.000Z

385

Interference of fission amplitudes of neutron resonances and T-odd asymmetry for various prescission third particles in the ternary fission of nuclei  

SciTech Connect (OSTI)

Differential cross sections for reactions of the true ternary fission of nuclei that was induced by cold polarized neutrons were constructed with allowance of the effect that Coriolis interaction and the interference between fission amplitudes of neutron resonances excited in fissile nuclei upon incidentneutron capture by target nuclei exerted on angular distributions of prescission third particles (alpha particles, neutrons, or photons). It is shown that T -odd TRI- and ROT-type asymmetries for prescission alpha particles are associated with, respectively, the odd and even components of the Coriolis interaction-perturbed amplitude of angular distributions of particles belonging to the types indicated above. These asymmetries have angular distributions differing from each other and stemming from a nontrivial dependence of these components on the neutron-resonance spins J{sub s} and their projections K{sub s} onto the symmetry axis of the nucleus involved. It is shown that angular distributions of prescission photons and neutrons from reactions of the ternary fission of nuclei that is induced by cold polarized neutrons are determined by the effect of Coriolis forces exclusively. Therefore, the emerging T-odd asymmetries have a character of a ROT-type asymmetry and are universal for all target nuclei.

Kadmensky, S. G., E-mail: kadmensky@phys.vsu.ru [Voronezh State University (Russian Federation); Bunakov, V. E. [Russian Academy of Sciences, Petersburg Nuclear Physics Institute (Russian Federation); Kadmensky, S. S. [Voronezh State University (Russian Federation)

2011-12-15T23:59:59.000Z

386

Economics UMass Lowell Commonwealth Honors Track  

E-Print Network [OSTI]

Economics UMass Lowell Commonwealth Honors Track Fall 2013 and Beyond Freshman Year/ Fall Semester.201 (H) Honors Economics I 3 49.202 Economics II 3 92.121 Pre-calc or any higher level 3 92.109 First Year Seminar 1 16 16 Sophomore Year/Fall Semester Cr Sophomore/Spring Semester 49.3/4 Economics

Massachusetts at Lowell, University of

387

Locating and tracking assets using RFID  

E-Print Network [OSTI]

. In this research, we will focus on how to ?nd the location of an item by using RFID in real time indoors to track equipment. When an item needs to be located, the purpose of using RFID is to minimize the searching time, e?ort, and investment cost. Thus...

Kim, Gak Gyu

2009-05-15T23:59:59.000Z

388

Tracking Mobile Units for Dependable Message Delivery  

E-Print Network [OSTI]

Tracking Mobile Units for Dependable Message Delivery Amy L. Murphy, Member, IEEE Computer Society at their disposal at any time, mobile computing is developing as an important research area. One of the fundamental problems in mobility is maintaining connectivity through message passing as the user moves through

Zhou, Yuanyuan

389

Software for precise tracking of cell proliferation  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer We developed software for analyzing cultured cells that divide as well as migrate. Black-Right-Pointing-Pointer The active contour model (Snakes) was used as the core algorithm. Black-Right-Pointing-Pointer The time backward analysis was also used for efficient detection of cell division. Black-Right-Pointing-Pointer With user-interactive correction functions, the software enables precise tracking. Black-Right-Pointing-Pointer The software was successfully applied to cells with fluorescently-labeled nuclei. -- Abstract: We have developed a multi-target cell tracking program TADOR, which we applied to a series of fluorescence images. TADOR is based on an active contour model that is modified in order to be free of the problem of locally optimal solutions, and thus is resistant to signal fluctuation and morphological changes. Due to adoption of backward tracing and addition of user-interactive correction functions, TADOR is used in an off-line and semi-automated mode, but enables precise tracking of cell division. By applying TADOR to the analysis of cultured cells whose nuclei had been fluorescently labeled, we tracked cell division and cell-cycle progression on coverslips over an extended period of time.

Kurokawa, Hiroshi [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan) [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Noda, Hisayori [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan) [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Sugiyama, Mayu [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan) [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Sakaue-Sawano, Asako [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan) [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); Life Function and Dynamics, ERATO, JST, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); Fukami, Kiyoko [School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan)] [School of Life Science, Tokyo University of Pharmacy and Life Science, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392 (Japan); Miyawaki, Atsushi, E-mail: matsushi@brain.riken.jp [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan) [Brain Science Institute, RIKEN, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan); Life Function and Dynamics, ERATO, JST, 2-1 Hirosawa, Wako-city, Saitama 351-0198 (Japan)

2012-01-20T23:59:59.000Z

390

Copyright Siemens Business Services Patient Tracking  

E-Print Network [OSTI]

Copyright Siemens Business Services Patient Tracking based on RFID labels ThomasThomas JellJell Principal ConsultantPrincipal Consultant DirectorDirector SBS SI 22 #12;2 Siemens One Projects SBS Companies / Goverment #12;3 Siemens One Projects Showroom GfM Furniture Designer Knock Offs ( Theft

Manstein, Dietmar J.

391

Double tracks test site characterization report  

SciTech Connect (OSTI)

This report presents the results of site characterization activities performed at the Double Tracks Test Site, located on Range 71 North, of the Nellis Air Force Range (NAFR) in southern Nevada. Site characterization activities included reviewing historical data from the Double Tracks experiment, previous site investigation efforts, and recent site characterization data. The most recent site characterization activities were conducted in support of an interim corrective action to remediate the Double Tracks Test Site to an acceptable risk to human health and the environment. Site characterization was performed using a phased approach. First, previously collected data and historical records sere compiled and reviewed. Generalized scopes of work were then prepared to fill known data gaps. Field activities were conducted and the collected data were then reviewed to determine whether data gaps were filled and whether other areas needed to be investigated. Additional field efforts were then conducted, as required, to adequately characterize the site. Characterization of the Double Tracks Test Site was conducted in accordance with the US Department of Energy`s (DOE) Streamlined Approach for Environmental Restoration (SAFER).

NONE

1996-05-01T23:59:59.000Z

392

Ubiquitous Computing, Customer Tracking, and Price Discrimination  

E-Print Network [OSTI]

Ubiquitous Computing, Customer Tracking, and Price Discrimination Alessandro Acquisti H. John Heinz's analysis is the possibility of combining context, historical, location and other personal data to dynamically alter the price of a product for each consumer - a form of price discrimination also known

Sadeh, Norman M.

393

Situational Awareness: Personalizing Issue Tracking Systems  

E-Print Network [OSTI]

Situational Awareness: Personalizing Issue Tracking Systems Olga Baysal, Reid Holmes, and Michael W. Godfrey Software Architecture Group (SWAG) David R. Cheriton School of Computer Science, University role in ongoing software development; they are used by developers to support collaborative bug fixing

Godfrey, Michael W.

394

Predictive tracking control of constrained nonlinear systems  

E-Print Network [OSTI]

"diffusive" and "constant" parameter dynamics, by means of a simulation example. Finally Section 6 draws some of constrained nonlinear systems are proposed. Simulation experiments demonstrate the good tracking properties, the controller directly synthesizes the plant control input and, hence, has more freedom than the RG which can

Chisci, Luigi

395

Additive manufacturing of metallic tracks on  

E-Print Network [OSTI]

Additive manufacturing of metallic tracks on green ceramic/dielectrics Problem this technology microelectronics such as manufacture of LTCC ceramic/ Dielectric antenna and rapid PCB prototyping or repair (note: may require additional tooling/ set up time) · Rapid Prototyping & small scale manufacture

Painter, Kevin

396

Prof. Alessandro De Luca Trajectory Tracking Control  

E-Print Network [OSTI]

Robotics 2 Prof. Alessandro De Luca Trajectory Tracking Control #12;Inverse dynamics control given the robot dynamic model ! B(q)q + n(q,q) = u and a twice-differentiable desired trajectory for t [0,T] ! qd state) ! c(q,q) + g(q) + friction model Robotics 2 2 . . #12;In practice ... " initial state is "not

De Luca, Alessandro

397

Cloud Tracking in Cloud-Resolving Models  

E-Print Network [OSTI]

Cloud Tracking in Cloud-Resolving Models RMetS Conference 4th September 2007 Bob Plant Department of Meteorology, University of Reading, UK #12;Introduction Obtain life cycle statistics for clouds in CRM simulations What is the distribution of cloud lifetimes? What factors determine the lifetime of an individual

Plant, Robert

398

Optical Blade Position Tracking System Test  

SciTech Connect (OSTI)

The Optical Blade Position Tracking System Test measures the blade deflection along the span of the blade using simple off-the-shelf infrared security cameras along with blade-mounted retro-reflective tape and video image processing hardware and software to obtain these measurements.

Fingersh, L. J.

2006-01-01T23:59:59.000Z

399

Plastics Engineering UMass Lowell Commonwealth Honors Track  

E-Print Network [OSTI]

Plastics Engineering UMass Lowell Commonwealth Honors Track Fall 2013 and Beyond Freshman Year Sophomore Year/Fall Semester Cr Sophomore/Spring Semester 26.001 Plastics Safety Lecture 0 26.002 Plastics Safety Lecture 0 26.201 Polymeric Materials I 3 26.202 Polymeric Materials II 3 26.215 Plastics Proc. Eng

Massachusetts at Lowell, University of

400

Nuclear Engineering Catalog 2013 Traditional Track  

E-Print Network [OSTI]

Nuclear Engineering Catalog 2013 Traditional Track Fall Math 141 or 147 (4) FA, SP, SU English 101-approved by the department advisor. Courses in Nuclear Engineering other than 500, 502 and 598 may also be used as technical, which depends on academic performance. Factors considered include overall grade point average

Tennessee, University of

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Gas Filled Detectors counting & tracking of  

E-Print Network [OSTI]

Gas Filled Detectors counting & tracking of particles energy loss generation of electron-ion+ pairs #12;Gas Filled Detectors Primary and Total Ionization fast charged particles ionize the atoms of a gas fraction of resulting primary electrons have enough kinetic energy to ionize other atoms #12;Gas Filled

Peletier, Reynier

402

Chemistry UMass Lowell Commonwealth Honors Track  

E-Print Network [OSTI]

Chemistry UMass Lowell Commonwealth Honors Track Scholarship Rises. Freshman Year/ Fall Semester Cr) Honors Chemistry I 3 84.136 (H) Honors Chemistry II 3 84.123 (H) Honors Chemistry I Lab 1 84.124 (H) Honors Chemistry II Lab 1 92.131 Calculus I 4 92.132 Honors Calculus II 4 Hon 110 Honors FYSH (AH) 3 Gen

Massachusetts at Lowell, University of

403

Assessment of University Sustainability Activities SUSTAINABILITY TRACKING,  

E-Print Network [OSTI]

Assessment of University Sustainability Activities under the SUSTAINABILITY TRACKING, ASSESSMENT Rashed-Ali, PhD. Prepared for: The UTSA Sustainability Council May 3rd , 2011 #12;yhd/s ^hDD Zz 2 | P a g-Ali, Assistant Professor in the College of Architecture, conducted a survey and assessment of UTSA sustainability

Dodla, Ramana

404

TAGGING, TRACKING AND LOCATING WITHOUT GPS  

SciTech Connect (OSTI)

The Savannah River National Laboratory (SRNL) was requested to lead a Law Enforcement Working Group that was formed to collaborate on common operational needs. All agencies represented on the working group ranked their need to tag, track, and locate a witting or unwitting target as their highest priority. Specifically, they were looking for technologies more robust than Global Positioning Satellite (GPS), could communicate back to the owner, and worked where normal cell phone communications did not work or were unreliable. SRNL brought together multiple technologies in a demonstration that was held in in various Alaska venues, including metropolitan, wilderness, and at-sea that met the working group's requirements. Using prototypical technologies from Boeing, On Ramp, and Fortress, SRNL was able to demonstrate the ability to track personnel and material in all scenarios including indoors, in heavily wooden areas, canyons, and in parking garages. In all cases GPS signals were too weak to measure. Bi-directional communication was achieved in areas that Wi-Fi, cell towers, or traditional radios would not perform. The results of the exercise will be presented. These technologies are considered ideal for tracking high value material such has nuclear material with a platform that allows seamless tracking anywhere in the world, indoors or outdoors.

Cordaro, J.; Coleman, T.; Shull, D.

2012-07-08T23:59:59.000Z

405

ADAPTIVE ROBUST TRACKING CONTROL OF PRESSURE  

E-Print Network [OSTI]

accuracy of pressure trajectory in the chamber when the pneumatic cylinder is moving. Off-line fitting, it is necessary to utilize the adaptive model compensation for improving the tracking accuracy of pressure and attenuation in pneumatic lines, valve dynamics, flow nonlinearities through the valve orifice, piston friction

Yao, Bin

406

Particle Tracking in Circular Accelerators Using the Exact Hamiltonian in SixTrack  

E-Print Network [OSTI]

Particle motion in accelerators is in general complex. Tracking codes are developed to simulate beam dynamics in accelerators. SixTrack is a long lived particle tracking code maintained at CERN, the European Organization for Nuclear Research. A particle accelerator consists of a large number of magnets and other electromagnetic devices that guide the particle through the accelerator. Each device defines its own equation of motion, which often cannot be solved exactly. For this purpose, a number of approximations are introduced in order to facilitate the solution and to speed up the computation. In a high-energy accelerator, the particle has small transverse momentum components. This is exploited in the small-angle approximation. In this approximation the equations of motion are expanded to a low order in the transverse momentum components. In low-energy particle accelerators, or in tracking with large momentum deviations, this approximation is invalid. The equations of motion of a particle passing through a f...

Fjellstrom, Mattias; Hansson, Johan

2013-12-13T23:59:59.000Z

407

WIPP Transparency Project - container tracking and monitoring demonstration using the Authenticated Tracking and Monitoring System (ATMS)  

SciTech Connect (OSTI)

The Authenticated Tracking and Monitoring System (ATMS) is designed to answer the need for global monitoring of the status and location of proliferation-sensitive items on a worldwide basis, 24 hours a day. ATMS uses wireless sensor packs to monitor the status of the items within the shipment and surrounding environmental conditions. Receiver and processing units collect a variety of sensor event data that is integrated with GPS tracking data. The collected data are transmitted to the International Maritime Satellite (INMARSAT) communication system, which then sends the data to mobile ground stations. Authentication and encryption algorithms secure the data during communication activities. A typical ATMS application would be to track and monitor the stiety and security of a number of items in transit along a scheduled shipping route. The resulting tracking, timing, and status information could then be processed to ensure compliance with various agreements.

SCHOENEMAN, J. LEE; SMARTT, HEIDI ANNE; HOFER, DENNIS

2000-01-27T23:59:59.000Z

408

SunShot Award Helps Solar Tracking Company Expand Internationally...  

Office of Environmental Management (EM)

SunShot Award Helps Solar Tracking Company Expand Internationally SunShot Award Helps Solar Tracking Company Expand Internationally October 30, 2014 - 5:46pm Addthis SunShot...

409

Peak power tracking for a solar buck charger  

E-Print Network [OSTI]

This thesis discusses the design, implementation, and testing of a buck converter with peak power tracking. The peak power tracker uses a perturb and observe algorithm to actively track the solar panel's peak power point ...

Cohen, Jeremy Michael, M. Eng. Massachusetts Institute of Technology

2010-01-01T23:59:59.000Z

410

Advances in Visual Tracking Ming-Hsuan Yang  

E-Print Network [OSTI]

detector [Harris and Stephens, 1988] SIFT (Scale-Invariant Feature Transform) [Lowe, 2004] SURF (Speeded Up at People and Objects Dudek Tracking and appearance modeling Lee walking 3D human tracking Tom and Jerry

Yang, Ming-Hsuan

411

Biomedical Engineering AB Track Rev. October 2012 1/2  

E-Print Network [OSTI]

Biomedical Engineering AB Track Rev. October 2012 1/2 Plan of Study for the Biomedical or summer project resulting in a significant written report _______ #12;Biomedical Engineering AB Track Rev

412

Tracking in a Spaghetti Bowl: Monitoring Transactions Using Footprints  

E-Print Network [OSTI]

adhere to the best practices such as those ad- vocated by the ITIL specifications to keep track of its

Anandkumar, Animashree

413

Track 7: Environmental Protection, Environmental Management System (EMS), "Greening Initiatives"  

Broader source: Energy.gov [DOE]

ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 7: Environmental Protection, Environmental Management System (EMS), "Greening Initiatives"

414

Track 1: Safety Culture- Taking ISMS to the Next Level  

Broader source: Energy.gov [DOE]

ISM Workshop Presentations Knoxville Convention Center, Knoxville, TN August 2009 Track 1: Safety Culture - Taking ISMS to the Next Level

415

Key to images: [1] Model system: fission yeast [2] Cryo-EM structure  

E-Print Network [OSTI]

Key to images: [1] Model system: fission yeast [2] Cryo-EM structure of the MCM helicase [3 combing [8] Model system: Xenopus [9] Extreme environments [10] Model system: C.elegans. Background image of the evolution of the replication machinery highlighted. BSRC B306 Email: sam31@st-and.ac.uk 1 2 3 4 5 6 7 8 9 10

Brierley, Andrew

416

VII. Nuclear Chemistry (Chapter 17) A. Modes of radioactive decay, nuclear reactions, fission, fusion  

E-Print Network [OSTI]

40 VII. Nuclear Chemistry (Chapter 17) A. Modes of radioactive decay, nuclear reactions, fission #12;41 These masses are not exactly integer multiples due to nuclear interactions between the protons differences via the famous formula E = mc2 . Nuclear Fusion! For example, if you combine 2 protons and two

417

PHYSICAL REVIEW C 87, 014617 (2013) Monte Carlo Hauser-Feshbach predictions of prompt fission rays  

E-Print Network [OSTI]

Nuclear Theory Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA (Received 14 for the evaporation of the excited fission fragments. Remaining free model parameters, such as excitation energy, multiplicity distribution, average multiplicity and energy, and multiplicity distribution, are calculated

Danon, Yaron

418

Multiple-humped fission and fusion barriers of the heaviest elements and ellipsoidal deformations  

E-Print Network [OSTI]

leading possibly to superheavy elements, double-humped potential barriers appear for cold fusionMultiple-humped fission and fusion barriers of the heaviest elements and ellipsoidal deformations G barriers and the predicted half-lives of actinides follow the experimental results. In the fusion path

Boyer, Edmond

419

Detection of uranium-based nuclear weapons using neutron-induced fission  

SciTech Connect (OSTI)

Although plutonium-based nuclear weapons can usually be detected by their spontaneous emission of neutrons and gammas, the radiation emitted by weapons based entirely on highly-enriched uranium can often be easily shielded. Verification of a treaty that limits the number of such weapons may require an active technique, such as interrogating the suspect assembly with an external neutron source and measuring the number of fission neutrons produced. Difficulties include distinguishing between source and fission neutrons, the variations in yield for different materials and geometries, and the possibility of non-nuclear weapons that may contain significant amounts of fissionable depleted uranium. We describe simple measurements that test the induced-fission technique using an isotopic Am-Li source, an novel energy-sensitive neutron detector, and several small assemblies containing {sup 235}U, {sup 238}U, lead, and polyethylene. In all cases studied, the neutron yields above the source energy are larger for the {sup 235}U assemblies than for assemblies containing only lead or depleted uranium. For more complex geometries, corrections for source transmission may be necessary. The results are promising enough to recommend further experiments and calculations using examples of realistic nuclear and non-nuclear weapons. 5 refs., 11 figs.

Moss, C.E.; Byrd, R.C.; Feldman, W.C.; Auchampaugh, G.F.; Estes, G.P. [Los Alamos National Lab., NM (United States); Ewing, R.I.; Marlow, K.W. [Sandia National Labs., Albuquerque, NM (United States)

1991-12-01T23:59:59.000Z

420

Detection of uranium-based nuclear weapons using neutron-induced fission  

SciTech Connect (OSTI)

Although plutonium-based nuclear weapons can usually be detected by their spontaneous emission of neutrons and gammas, the radiation emitted by weapons based entirely on highly-enriched uranium can often be easily shielded. Verification of a treaty that limits the number of such weapons may require an active technique, such as interrogating the suspect assembly with an external neutron source and measuring the number of fission neutrons produced. Difficulties include distinguishing between source and fission neutrons, the variations in yield for different materials and geometries, and the possibility of non-nuclear weapons that may contain significant amounts of fissionable depleted uranium. We describe simple measurements that test the induced-fission technique using an isotopic Am-Li source, an novel energy-sensitive neutron detector, and several small assemblies containing {sup 235}U, {sup 238}U, lead, and polyethylene. In all cases studied, the neutron yields above the source energy are larger for the {sup 235}U assemblies than for assemblies containing only lead or depleted uranium. For more complex geometries, corrections for source transmission may be necessary. The results are promising enough to recommend further experiments and calculations using examples of realistic nuclear and non-nuclear weapons. 5 refs., 11 figs.

Moss, C.E.; Byrd, R.C.; Feldman, W.C.; Auchampaugh, G.F.; Estes, G.P. (Los Alamos National Lab., NM (United States)); Ewing, R.I.; Marlow, K.W. (Sandia National Labs., Albuquerque, NM (United States))

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Comparison of neutron diffusion and Monte Carlo simulations of a fission wave  

E-Print Network [OSTI]

common con- figuration a fertile material, such as depleted uranium, is subjected to a fast neutron flux). The fresh fuel zone consisted of depleted uranium groups have shown that fission waves could form in uranium and potentially be used as the basis

Deinert, Mark

422

A dynamical treatment of isobaric widths in fission : An example of frozen quantal fluctuations  

E-Print Network [OSTI]

in the case of low energy nuclear fission since the excitation energies involved at scission are only to heavy ion reactions is discussed. Tome 41 No 3 ler FEVRIER 1980 LE JOURNAL DE PHYSIQUE - LETTRES has been recently underlined in heavy ion reactions [1], [2], [3], [4]. Experimentally it appears [1

Boyer, Edmond

423

Release and transport of fission product cesium in the TMI-2 accident  

SciTech Connect (OSTI)

Approximately 50% of the fission product cesium was released from the overheated UO/sub 2/ fuel in the TMI-2 accident. Steam that boiled away from a water pool in the bottom of the reactor vessel transported the released fission products throughout the reactor coolant system (RCS). Some fission products passed directly through a leaking valve with steam and water into the containment structure, but most deposited on dry surfaces inside of the RCS before being dissolved or resuspended when the RCS was refilled with water. A cesium transport model was developed that extended measured cesium in the RCS back to the first day of the accident. The model revealed that approx.62% of the released /sup 137/Cs deposited on dry surfaces inside of the RCS before being slowly leached and transported out of the RCS in leaked or letdown water. The leach rates from the model agreed reasonably well with those measured in the laboratory. The chemical behavior of cesium in the TMI-2 accident agreed with that observed in fission product release tests at Oak Ridge National Laboratory (ORNL).

Lorenz, R.A.; Collins, J.L.

1986-01-01T23:59:59.000Z

424

Fission signal detection using helium-4 gas fast neutron scintillation detectors  

SciTech Connect (OSTI)

We demonstrate the unambiguous detection of the fission neutron signal produced in natural uranium during active neutron interrogation using a deuterium-deuterium fusion neutron generator and a high pressure {sup 4}He gas fast neutron scintillation detector. The energy deposition by individual neutrons is quantified, and energy discrimination is used to differentiate the induced fission neutrons from the mono-energetic interrogation neutrons. The detector can discriminate between different incident neutron energies using pulse height discrimination of the slow scintillation component of the elastic scattering interaction between a neutron and the {sup 4}He atom. Energy histograms resulting from this data show the buildup of a detected fission neutron signal at higher energies. The detector is shown here to detect a unique fission neutron signal from a natural uranium sample during active interrogation with a (d, d) neutron generator. This signal path has a direct application to the detection of shielded nuclear material in cargo and air containers. It allows for continuous interrogation and detection while greatly minimizing the potential for false alarms.

Lewis, J. M., E-mail: lewisj@ufl.edu; Kelley, R. P.; Jordan, K. A. [Nuclear Engineering Program, University of Florida, Gainesville, Florida 32611 (United States); Murer, D. [Arktis Radiation Detectors Ltd., 8045 Zurich (Switzerland)

2014-07-07T23:59:59.000Z

425

innovati nSinglet Fission Holds Two-for-One Potential in Solar Cells  

E-Print Network [OSTI]

of light. · This energy excites the electrons from their low-energy ground state (S0) to an excited high-energy, including 10% post consumer waste. The bottom line is that one high-energy photon can produce two electron energy in excess of the bandgap energy is lost as wasted heat. In contrast, singlet fission produces the

426

ENVIRONMENTAL STUDIES TRACK (B.S.) 2011-2012 CATALOG  

E-Print Network [OSTI]

June 2011 ENVIRONMENTAL STUDIES TRACK (B.S.) 2011-2012 CATALOG There are three tracks in Interdisciplinary Studies (IS). This handout is for the Environmental Studies track. Office Classroom I Suite 302. It is a university-wide program designed for students seeking a combination of studies. The Environmental Studies

Van Stryland, Eric

427

ENVIRONMENTAL STUDIES TRACK (B.S.) 2012-2013 CATALOG  

E-Print Network [OSTI]

June 2012 ENVIRONMENTAL STUDIES TRACK (B.S.) 2012-2013 CATALOG There are three tracks in Interdisciplinary Studies (IS). This handout is for the Environmental Studies track. Office Classroom I Suite 302. It is a university-wide program designed for students seeking a combination of studies. The Environmental Studies

Foroosh, Hassan

428

People Tracking with Human Motion Predictions from Social Forces  

E-Print Network [OSTI]

People Tracking with Human Motion Predictions from Social Forces Matthias Luber Johannes A. Stork Gian Diego Tipaldi Kai O. Arras Abstract-- For many tasks in populated environ- ments, robots need to keep track of current and future motion states of people. Most approaches to people tracking make weak

Arras, Kai O.

429

Tracking Interacting People Stephen J. McKenna  

E-Print Network [OSTI]

people move in groups or interact with other peo- ple cause considerable difficulty to many trackingTracking Interacting People Stephen J. McKenna Department of Applied Computing University of Dundee, wechsler @cs.gmu.edu Abstract A computer vision system for tracking multiple people in relatively

Duric, Zoran

430

Tracking Groups of People Stephen J. McKenna  

E-Print Network [OSTI]

in groups or interact with other people cause considerable difficulty for many tracking schemes. HoweverTracking Groups of People Stephen J. McKenna Department of Applied Computing, University of Dundee, University of Maryland, College Park, MD 20742-3275 A computer vision system for tracking multiple people

Duric, Zoran

431

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

SciTech Connect (OSTI)

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

Blaise Collin

2014-09-01T23:59:59.000Z

432

Experimental Target Injection and Tracking System  

SciTech Connect (OSTI)

Targets must be injected into an IFE power plant with an accuracy of and plusmn; 5 mm at a rate of approximately 5 to 10 each second. Targets must be tracked very accurately to allow driver beams to be aligned with defined points on the targets with accuracy {+-}200{mu}m for indirect drive and {+-}20{mu}m for direct drive. An experimental target injection and tracking system has been designed and is being constructed at General Atomics to investigate injection and tracking of both direct drive and indirect drive targets. The design is modular to allow testing of alternate target acceleration and tracking methods. The injector system will be used as a tool for testing the survivability of various target designs and provide feed back to the target designers. This 30 m long system will be the centerpiece of a Facility for developing IFE target fabrication and injection technologies. A high-speed high-flow gas valve (designed and built by Oak Ridge National Laboratory) will provide helium propellant gas to the targets. To avoid target damage from excessive acceleration, an 8 m gun barrel is being built to achieve 400 m/s target speed while not exceeding 10,000 m/s{sup 2} acceleration. Direct-drive targets are protected in the barrel by sabots that are spring loaded to separate into two halves after acceleration. A sabot deflector directs the sabot halves away from the target injection path. Gas expansion chambers and orifices, keep propellant gas out of the target-tracking region. Targets will be optically tracked with laser beams and line scan cameras. High-speed computations will calculate target position in less than 2 ms based on the output from the line-scan cameras. Target position and arrival time to a plane in the reaction chamber center will be predicted in real-time based on early target position measurements. The system design, construction progress, and early testing results will be presented.

Petzoldt, R.W. [General Atomics (United States); Alexander, N.B. [General Atomics (United States); Drake, T.J. [General Atomics (United States); Goodin, D.T. [General Atomics (United States); Stemke, R.W. [General Atomics (United States); Jonestrask, K

2003-07-15T23:59:59.000Z

433

Evidence of Southern Health  

E-Print Network [OSTI]

POS Evidence of Coverage Southern Health Services, Inc. SH.POS.11-09 #12;Table of Contents SH................................................................................................10 Facts about Southern Health .....................................................................12 Members' Responsibilities to Know How and When to Seek Care ............................13 Section

Acton, Scott

434

Innovative Mobile Technologies for Asset Tracking  

E-Print Network [OSTI]

ICEBO Session 15 - Innovative Mobile Technologies for Asset Tracking Agenda ? Learn how clients have mobilized their enterprise data to increase the consistent capture and reporting of important building information, from lease data to work... orders to space & occupancy costs. ? Top 5 lessons learned implementing a mobile solution Who We Are ? Experts in both Real Property and Facilities Management Business and Technology ? Over 250 years of combined experience that encompasses facility...

Liko, W.

2013-01-01T23:59:59.000Z

435

Longitudinal and transverse tracking studies for ESS  

SciTech Connect (OSTI)

The techniques currently being employed to model beam transport and injection into the ESS accumulator rings are described. These use a combination of one dimensional (longitudinal) and two-dimensional (transverse) particle tracking codes, incorporating a variety of methods of simulating self-field effects. A description of the proposed mechanism for painting longitudinal and transverse phase-space for ESS is given, and the results of the modeling and subsequent optimization are discussed. {copyright} {ital 1996 American Institute of Physics.}

Prior, C.R. [Rutherford Appleton Laboratory, Chilton, Oxon (United Kingdom)

1996-06-01T23:59:59.000Z

436

An interface tracking model for droplet electrocoalescence.  

SciTech Connect (OSTI)

This report describes an Early Career Laboratory Directed Research and Development (LDRD) project to develop an interface tracking model for droplet electrocoalescence. Many fluid-based technologies rely on electrical fields to control the motion of droplets, e.g. microfluidic devices for high-speed droplet sorting, solution separation for chemical detectors, and purification of biodiesel fuel. Precise control over droplets is crucial to these applications. However, electric fields can induce complex and unpredictable fluid dynamics. Recent experiments (Ristenpart et al. 2009) have demonstrated that oppositely charged droplets bounce rather than coalesce in the presence of strong electric fields. A transient aqueous bridge forms between approaching drops prior to pinch-off. This observation applies to many types of fluids, but neither theory nor experiments have been able to offer a satisfactory explanation. Analytic hydrodynamic approximations for interfaces become invalid near coalescence, and therefore detailed numerical simulations are necessary. This is a computationally challenging problem that involves tracking a moving interface and solving complex multi-physics and multi-scale dynamics, which are beyond the capabilities of most state-of-the-art simulations. An interface-tracking model for electro-coalescence can provide a new perspective to a variety of applications in which interfacial physics are coupled with electrodynamics, including electro-osmosis, fabrication of microelectronics, fuel atomization, oil dehydration, nuclear waste reprocessing and solution separation for chemical detectors. We present a conformal decomposition finite element (CDFEM) interface-tracking method for the electrohydrodynamics of two-phase flow to demonstrate electro-coalescence. CDFEM is a sharp interface method that decomposes elements along fluid-fluid boundaries and uses a level set function to represent the interface.

Erickson, Lindsay Crowl

2013-09-01T23:59:59.000Z

437

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

DOE Patents [OSTI]

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.

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

2009-01-27T23:59:59.000Z

438

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

DOE Patents [OSTI]

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.

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

2009-01-06T23:59:59.000Z

439

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

DOE Patents [OSTI]

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.

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

2009-05-05T23:59:59.000Z

440

ALS Evidence Confirms Combustion Theory  

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

ALS Evidence Confirms Combustion Theory ALS Evidence Confirms Combustion Theory Print Wednesday, 22 October 2014 11:43 Researchers recently uncovered the first step in the process...

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Realistic fission models, new beta-decay half-lives and the r-process in neutron star mergers  

SciTech Connect (OSTI)

Almost half of heavy nuclei beyond iron are considered to be produced by rapid neutron capture process (r-process). This process occurs in the neutron-rich environment such as core-collapse supernovae or neutron star mergers, but the main production site is still unknown. In the r-process of neutron star mergers, nuclear fission reactions play an important role. Also beta-decay half-lives of magic nuclei are crucial for the r-process. We have carried out r-process nucleosynthesis calculations based upon new theoretical estimates of fission fragment distributions and new beta-decay half-lives for N=82 nuclei measured at RIBF-RIKEN. We investigate the effect of nuclear fission on abundance patterns in the matter ejected from neutron star mergers with two different fission fragment mass distributions. We also discuss how the new experimental beta-decay half-lives affect the r-process.

Shibagaki, S.; Kajino, T. [Department of Astronomy, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan and National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Chiba, S. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo, 152-8850 (Japan); Lorusso, G.; Nishimura, S. [RIKEN Nishina Center, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Mathews, G. J. [Center for Astrophysics, Department of Physics, University of Notre Dame, IN 46556 (United States)

2014-05-02T23:59:59.000Z

442

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

E-Print Network [OSTI]

DT Deuterium-Tritium DU Depleted Uranium FIMA Fission ofengine loaded with depleted uranium. In Proc. PHYSOR 2010,in the form of depleted uranium (DU). The remaining ~3,075

Kramer, Kevin James

2010-01-01T23:59:59.000Z

443

Method of assaying uranium with prompt fission and thermal neutron borehole logging adjusted by borehole physical characteristics. [Patient application  

DOE Patents [OSTI]

Uranium formations are assayed by prompt fission neutron logging techniques. The uranium in the formation is proportional to the ratio of epithermal counts to thermal or epithermal dieaway. Various calibration factors enhance the accuracy of the measurement.

Barnard, R.W.; Jensen, D.H.

1980-11-05T23:59:59.000Z

444

Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS  

SciTech Connect (OSTI)

Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS have been conducted. In this work, fission cross section resulted from MCNP6 prediction will be compared with result from TALYS calculation. MCNP6 with its event generator CEM03.03 and LAQGSM03.03 have been validated and verified for several intermediate and heavy nuclides fission reaction data and also has a good agreement with experimental data for fission reaction that induced by photons, pions, and nucleons at energy from several ten of MeV to about 1 TeV. The calculation that induced within TALYS will be focused mainly to several hundred MeV for actinide and sub-actinide nuclides and will be compared with MCNP6 code and several experimental data from other evaluator.

Perkasa, Y. S. [Department of Physics, Sunan Gunung Djati State Islamic University Bandung, Jl. A.H Nasution No. 105 Cibiru, Bandung (Indonesia); Waris, A., E-mail: awaris@fi.itb.ac.id; Kurniadi, R., E-mail: awaris@fi.itb.ac.id; Su'ud, Z., E-mail: awaris@fi.itb.ac.id [Nuclear Physics and Biophysics Research Division, Department of Physics, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesa No. 10 Bandung 40132 (Indonesia)

2014-09-30T23:59:59.000Z

445

Fission-fusion sociality in dusky dolphins (Lagenorhynchus obscurus), with comparisons to other dolphins and great apes  

E-Print Network [OSTI]

I examined fission-fusion sociality in dusky dolphins (Lagenorhynchus obscurus), and investigated aspects of social convergence between dolphins and great apes. I used boat-based group focal follows and photo-identification to collect data...

Pearson, Heidi Christine

2008-10-10T23:59:59.000Z

446

Study of heavy ion induced fission fragment angular and mass distribution at near and sub-coulomb barrier energies  

E-Print Network [OSTI]

The thesis presents investigations on the angular and mass distribution of fission fragments on heavy ion induced fission reactions. The present investigations address current issues in heavy ion induced fission reactions like finding the optimum entrance channel for the synthesis of super heavy elements (SHE). A double arm time of flight spectrometer over long flight path was used to measure the precise masses of complementary fission fragments. Necessary large area position sensitive gas detectors, the method of experiments and data analysis were developed. The first string of measurements were for a spherical target (209^Bi) with oxygen and fluorine projectiles. The next series of experiments were done using a deformed target (232^Th) with fluorine, oxygen and carbon projectiles.

T. K. Ghosh

2005-08-10T23:59:59.000Z

447

Proton-induced fission of actinides at energies 26.5 and 62.9 MeV--Theoretical interpretation  

SciTech Connect (OSTI)

Fission properties of proton-induced fission on {sup 232}Th, {sup 237}Np, {sup 238}U, {sup 239}Pu and {sup 241}Am targets, measured at the Louvain-la-Neuve cyclotron facility at proton energies of 26.5 and 62.9 MeV, are compared with the predictions of the state-of-the-art nuclear reaction code TALYS. The sensitivity of the calculations to the input parameters of the code and possible improvements are discussed.

Demetriou, P. [Institute of Nuclear Physics, NCSR 'Demokritos', 15310 Athens (Greece); Keutgen, Th.; Prieels, R.; El Masri, Y. [FNRS and Institut de Physique Nucleaire, Universite catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium)

2011-10-28T23:59:59.000Z

448

Nuclear Fission Reactor Safety Research in FP7 and future perspectives  

E-Print Network [OSTI]

The European Union (?U) has defined in the Europe 2020 strategy and 2050 Energy Roadmap its long-term vision for establishing a secure, sustainable and competitive energy system and setting up legally binding targets by 2020 for reducing greenhouse emissions, by increasing energy efficiency and the share of renewable energy sources while including a significant share from nuclear fission. Nuclear energy can enable the further reduction in harmful emissions and can contribute to the EUs competitive energy system, security of supply and independence from fossil fuels. Nuclear fission is a valuable option for those 14 EU countries that promote its use as part of their national energy mix. The European Group on Ethics in Science and New Technologies (EGE) adopted its Opinion No.27 An ethical framework for assessing research, production and use of energy and proposed an integrated ethics approach for the research, production and use of energy in the EU, seeking equilibrium among four criteria access ...

Garbil, Roger

2014-01-01T23:59:59.000Z

449

Pre-neutron emission mass distributions for low-energy neutron-induced actinide fission  

E-Print Network [OSTI]

According to the driving potential of a fissile system, we propose a phenomenological fission potential for a description of the pre-neutron emission mass distributions of neutron-induced actinide fission. Based on the nucleus-nucleus potential with the Skyrme energy-density functional, the driving potential of the fissile system is studied considering the deformations of nuclei. The energy dependence of the potential parameters is investigated based on the experimental data for the heights of the peak and valley of the mass distributions. The pre-neutron emission mass distributions for reactions 238U(n, f), 237Np(n, f), 235U(n, f), 232Th(n, f) and 239Pu(n, f) can be reasonably well reproduced. Some predictions for these reactions at unmeasured incident energies are also presented.

Xiaojun Sun; Chenggang Yu; Ning Wang

2012-01-15T23:59:59.000Z

450

Transient fission-gas behavior in uranium nitride fuel under proposed space applications. Doctoral thesis  

SciTech Connect (OSTI)

In order to investigate whether fission gas swelling and release would be significant factors in a space based nuclear reactor operating under the Strategic Defense Initiative (SDI) program, the finite element program REDSTONE (Routine For Evaluating Dynamic Swelling in Transient Operational Nuclear Environments) was developed to model the 1-D, spherical geometry diffusion equations describing transient fission gas behavior in a single uranium nitride fuel grain. The equations characterized individual bubbles, rather than bubble groupings. This limits calculations to those scenarios where low temperatures, low burnups, or both were present. Instabilities in the bubble radii calculations forced the implementation of additional constraints limiting the bubble sizes to minimum and maximum (equilibrium) radii. The validity of REDSTONE calculations were checked against analytical solutions for internal consistency and against experimental studies for agreement with swelling and release results.

Deforest, D.L.

1991-12-01T23:59:59.000Z

451

Fundamental Studies of Irradiation-Induced Defect Formation and Fission Product Dynamics in Oxide Fuels  

SciTech Connect (OSTI)

The objective of this research program is to address major nuclear fuels performance issues for the design and use of oxide-type fuels in the current and advanced nuclear reactor applications. Fuel performance is a major issue for extending fuel burn-up which has the added advantage of reducing the used fuel waste stream. It will also be a significant issue with respect to developing advanced fuel cycle processes where it may be possible to incorporate minor actinides in various fuel forms so that they can be 'burned' rather than join the used fuel waste stream. The potential to fission or transmute minor actinides and certain long-lived fission product isotopes would transform the high level waste storage strategy by removing the need to consider fuel storage on the millennium time scale.

James Stubbins

2012-12-19T23:59:59.000Z

452

Measured delayed neutron spectra from the fission of {sup 235}U and {sup 237}Np  

SciTech Connect (OSTI)

Texas A and M University (Texas A and M) in collaboration with Oak Ridge National Laboratory and the Japan Atomic Energy Research Institute, have been actively studying the delayed neutron emission characteristics of the higher actinide isotopes for several years. Recently, a proton recoil detector system was designed, built, and characterized for use in measuring delayed neutron energy spectra following neutron-induced fission. The system has been used to measure aggregate delayed neutron energy spectra from neutron-induced fission of {sup 235}U and {sup 237}Np. These spectra have also been compared to that calculated using individual precursor P{sub n} values, yields, and spectra from the ENDF/B-VI file.

Charlton, W.S.; Comfort, C.; Parish, T.A. [Texas A and M Univ., College Station, TX (United States); Raman, S. [Oak Ridge National Lab., TN (United States)

1998-12-31T23:59:59.000Z

453

Fission product chain yields and delayed neutrons: ANS standards 5. 2 and 5. 8  

SciTech Connect (OSTI)

Chain yields are the addition of the direct values along constant (Z + N) paths. The addition must also account for decay branching, especially for delayed neutrons that couple the mass chains. The result is the familiar double-humped plot of yield per fission versus mass number. The lines of stable nuclides and most probable yield are shown in the (Z,N) plane. Some modern measurements provide direct yields; other provide cumulative values for long-lived or stable products. Yield evaluations must account for each type of measurement and the degree of decay coupling, beginning with direct yields. For some fissioning nuclides at thermal or fast neutron incident energies, the amount of data is enormous; and for other nuclide-energy combinations, the data must be developed from systematics. Many applications of chain yields can use the same systematics to estimate independent values. The ANS 5.2 standard is currently in rough draft form for comment from working group members.

England, T.R. (Los Alamos National Lab., NM (United States)); Brady, M.C. (Oak Ridge National Lab., TN (United States)); Rider, B.F.

1990-01-01T23:59:59.000Z

454

Measurement of delayed-neutron yield from {sup 237}Np fission induced by thermal neutrons  

SciTech Connect (OSTI)

The delayed-neutron yield from thermal-neutron-induced fission of the {sup 237}Np nucleus was measured using a sample periodically exposed to a pulsed neutron beam with subsequent detection of neutrons during the time intervals between pulses. The experiment was realized on an Isomer-M setup mounted in the IBR-2 pulsed reactor channel equipped with a mirror neutron guide. The setup and the experimental procedure are described, the background sources are thoroughly analyzed, and the experimental data are presented. The total delayed-neutron yield from {sup 237}Np fission induced by thermal neutrons is {nu}{sub d} = 0.0110 {+-} 0.0009. This study was performed at the Frank Laboratory of Neutron Physics (JINR, Dubna)

Gundorin, N. A.; Zhdanova, K. V.; Zhuchko, V. E.; Pikelner, L. B., E-mail: plb@nf.jinr.ru; Rebrova, N. V.; Salamatin, I. M.; Smirnov, V. I.; Furman, V. I. [Joint Institute for Nuclear Research (Russian Federation)

2007-06-15T23:59:59.000Z

455

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

SciTech Connect (OSTI)

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.

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

2008-10-02T23:59:59.000Z

456

Safety and power multiplication aspects of mirror fusion-fission hybrids  

SciTech Connect (OSTI)

Recently, in a research project at Uppsala University a simplified neutronic model for a straight field line mirror hybrid has been devised and its most important operation parameters have been calculated under the constraints of a fission power production of 3 GW and that the effective multiplication factor k{sub eff} does not exceed 0.95. The model can be considered as representative for hybrids driven by other types of mirrors too. In order to reduce the demand on the fusion power of the mirror, a modified option of the hybrid has been considered that generates a reduced fission power of 1.5 GW with an increased maximal value k{sub eff}=0.97. The present paper deals with nuclear safety aspects of this type of hybrids. It presents and discusses calculation results of reactivity effects as well as of driver effects.

Noack, Klaus; Agren, Olov; Kaellne, Jan; Hagnestal, Anders; Moiseenko, Vladimir E. [Uppsala University, Angstroem Laboratory, Division of Electricity, Box 534, SE-751 21 Uppsala (Sweden); Institute of Plasma Physics, National Science Center 'Kharkiv Institute of Physics and Technology', Akademichna St. 1, 61108 Kharkiv (Ukraine)

2012-06-19T23:59:59.000Z

457

81929 - Fission-Product Separation Based on Room - Temperature Ionic Liquids  

SciTech Connect (OSTI)

This project has demonstrated that Sr2+ and Cs+ can be selectively extracted from aqueous solutions into ionic liquids using crown ethers and that unprecedented large distribution coefficients can be achieved for these fission products. The volume of secondary wastes can be significantly minimized with this new separation technology. Through the current EMSP funding, the solvent extraction technology based on ionic liquids has been shown to be viable and can potentially provide the most efficient separation of problematic fission products from high level wastes. The key results from the current funding period are the development of highly selective extraction process for cesium ions based on crown ethers and calixarenes, optimization of selectivities of extractants via systematic change of ionic liquids, and investigation of task-specific ionic liquids incorporating both complexant and solvent characteristics.

Robin D. Rogers

2004-12-09T23:59:59.000Z

458

Feasibility study of a fission supressed blanket for a tandem-mirror hybrid reactor  

SciTech Connect (OSTI)

A study of fission suppressed blankets for the tandem mirror not only showed such blankets to be feasible but also to be safer than fissioning blankets. Such hybrids could produce enough fissile material to support up to 17 light water reactors of the same nuclear power rating. Beryllium was compared to /sup 7/Li for neutron multiplication; both were considered feasible but the blanket with Li produced 20% less fissile fuel per unit of nuclear power in the reactor. The beryllium resource, while possibly being too small for extensive pure fusion application, would be adequate (with carefully planned industrial expansion) for the hybrid because of the large support ratio, and hence few hybrids required. Radiation damage and coatings for beryllium remain issues to be resolved by further study and experimentation.

Moir, R.W.; Lee, J.D.; Barr, W.L.

1981-10-05T23:59:59.000Z

459

Measurement of airborne fission products in Chapel Hill, NC, USA from the Fukushima I reactor accident  

E-Print Network [OSTI]

We present measurements of airborne fission products in Chapel Hill, NC, USA, from 62 days following the March 11, 2011, accident at the Fukushima I Nuclear Power Plant. Airborne particle samples were collected daily in air filters and radio-assayed with two high-purity germanium (HPGe) detectors. The fission products I-131 and Cs-137 were measured with maximum activities of 4.2 +/- 0.6 mBq/m^2 and 0.42 +/- 0.07 mBq/m^2 respectively. Additional activity from I-131, I-132, Cs-134, Cs-136, Cs-137 and Te-132 were measured in the same air filters using a low-background HPGe detector at the Kimballton Underground Research Facility (KURF).

MacMullin, S; Green, M P; Henning, R; Holmes, R; Vorren, K; Wilkerson, J F

2011-01-01T23:59:59.000Z

460

Total and spontaneous fission half-lives of the americium and curium nuclides  

SciTech Connect (OSTI)

The total half-life and the half-life for spontaneous fission are evaluated for the various long-lived nuclides of interest. Recommended values are presented for /sup 241/Am, /sup 242m/Am, /sup 243/Am, /sup 242/Cm, /sup 243/Cm, /sup 244/Cm, /sup 245/Cm, /sup 246/Cm, /sup 247/Cm, /sup 248/Cm, and /sup 250/Cm. The uncertainties are provided at the 95% confidence limit for each of the recommended values.

Holden, N.E.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fission track evidence" from the National Library of EnergyBeta (NLEBeta).
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461

Yields of delayed-neutron groups in thermal-neutron fission of sup 229 Th  

SciTech Connect (OSTI)

Absolute yields of five delayed-neutron groups in thermal-neutron fission of {sup 229}Th have been determined for the first time. A significant discrepancy is noted between the experimental yields of delayed neutrons of the fourth group and the corresponding theoretical values. From the results of the experimental studies, corrections have been determined for even--odd effects in the charge distributions of the yields of fragment nuclides.

Gudkov, A.N.; Koldobskii, A.B.; Krivasheev, S.V.; Lebedev, N.A.; Pchelin, V.A. (Moscow Engineering-Physics Institute (SU))

1989-06-01T23:59:59.000Z

462

Delayed neutrons as a probe of nuclear charge distribution in fission of heavy nuclei by neutrons  

E-Print Network [OSTI]

A method of the determination of cumulative yields of delayed neutron precursors is developed. This method is based on the iterative least-square procedure applied to delayed neutron decay curves measured after irradiation of sup 2 sup 3 sup 5 U sample by thermal neutrons. Obtained cumulative yields in turns were used for deriving the values of the most probable charge in low-energy fission of the above-mentioned nucleus.

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

2001-01-01T23:59:59.000Z

463

Modeling requirements for full-scope reactor simulators of fission-product transport during severe accidents  

SciTech Connect (OSTI)

This paper describes in the needs and requirements to properly and efficiently model fission product transport on full scope reactor simulators. Current LWR simulators can be easily adapted to model severe accident phenomena and the transport of radionuclides. Once adapted these simulators can be used as a training tool during operator training exercises for training on severe accident guidelines, for training on containment venting procedures, or as training tool during site wide emergency training exercises.

Ellison, P.G.; Monson, P.R. (Westinghouse Savannah River Co., Aiken, SC (United States)); Mitchell, H.A. (Concord Associates, Inc., Knoxville, TN (United States))

1990-01-01T23:59:59.000Z

464

Modeling requirements for full-scope reactor simulators of fission-product transport during severe accidents  

SciTech Connect (OSTI)

This paper describes in the needs and requirements to properly and efficiently model fission product transport on full scope reactor simulators. Current LWR simulators can be easily adapted to model severe accident phenomena and the transport of radionuclides. Once adapted these simulators can be used as a training tool during operator training exercises for training on severe accident guidelines, for training on containment venting procedures, or as training tool during site wide emergency training exercises.

Ellison, P.G.; Monson, P.R. [Westinghouse Savannah River Co., Aiken, SC (United States); Mitchell, H.A. [Concord Associates, Inc., Knoxville, TN (United States)

1990-12-31T23:59:59.000Z

465

Scaling Laws and Transient Times in 3He Induced Nuclear Fission  

E-Print Network [OSTI]

Fission excitation functions of compound nuclei in a mass region where shell effects are expected to be very strong are shown to scale exactly according to the transition state prediction once these shell effects are accounted for. The fact that no deviations from the transition state method have been observed within the experimentally investigated excitation energy regime allows one to assign an upper limit for the transient time of 10 zs.

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

1996-07-09T23:59:59.000Z

466

An analysis of tritium and fissile fuel exchange in fusion-fission systems  

E-Print Network [OSTI]

24 IV SYSTEMS STUDIES System Descriptions Parametric Studies Reference Case 25 25 27 30 RESULTS Fusile Inventory Hybrid Capital Costs System Sensitivity to Q Capital Costs for Tritium Production Reactors Doubling Time Effects Tritium... PAGE 26 28 III IV V System Sensitivity to the Fusile Inventory The Effect of the Tritium Production Reactor Capital Cost on the Cost of Electricity for the System The Effects on the System of Tritium Production in the Fission Power Reactors...

Rice, Brent Lee

1987-01-01T23:59:59.000Z

467

The fiftieth anniversary of the first public announcement of the successful test of fission: Proceedings  

SciTech Connect (OSTI)

This report contains comments and discussions on the history of fission. The following people comments and lectures are discussed in this report: Remarks and introduction of Maxine F. Singer; president's message, Maxine F. Singer; introduction of Stephen Joel Trachtenberg; President's message, Stephen Joel Trachtenberg; introduction of Frederick Seitz; lecture: Nuclear Science: Promises and Perceptions, '' Frederick Seitz; introduction of K. Alex Mueller; lecture: High Temperature Ferroelectricity and Superconductivity,'' introduction of Edward Teller; and lecture: Toward a More Secure World,'' Edward Teller.

Not Available

1989-01-01T23:59:59.000Z

468

A long term radiological risk model for plutonium-fueled and fission reactor space nuclear system  

SciTech Connect (OSTI)

This report describes the optimization of the RISK III mathematical model, which provides risk assessment for the use of a plutonium-fueled, fission reactor in space systems. The report discusses possible scenarios leading to radiation releases on the ground; distinctions are made for an intact reactor and a dispersed reactor. Also included are projected dose equivalents for various accident situations. 54 refs., 31 figs., 11 tabs. (TEM)

Bartram, B.W.; Dougherty, D.K.

1987-01-01T23:59:59.000Z

469

Theoretical investigation of the impact of grain boundaries and fission gases on UO2 thermal conductivity  

SciTech Connect (OSTI)

Thermal conductivity is one of the most important metrics of nuclear fuel performance. Therefore, it is crucial to understand the impact of microstructure features on thermal conductivity, especially since the microstructure evolves with burn-up or time in the reactor. For example, UO{sub 2} fuels are polycrystalline and for high-burnup fuels the outer parts of the pellet experience grain sub-division leading to a very fine grain structure. This is known to impact important physical properties such as thermal conductivity as fission gas release. In a previous study, we calculated the effect of different types of {Sigma}5 grain boundaries on UO{sub 2} thermal conductivity and predicted the corresponding Kapitza resistances, i.e. the resistance of the grain boundary in relation to the bulk thermal resistance. There have been reports of pseudoanisotropic effects for the thermal conductivity in cubic polycrystalline materials, as obtained from molecular dynamics simulations, which means that the conductivity appears to be a function of the crystallographic direction of the temperature gradient. However, materials with cubic symmetry should have isotropic thermal conductivity. For this reason it is necessary to determine the cause of this apparent anisotropy and in this report we investigate this effect in context of our earlier simulations of UO{sub 2} Kapitza resistances. Another source of thermal resistance comes from fission products and fission gases. Xe is the main fission gas and when generated in sufficient quantity it dissolves from the lattice and forms gas bubbles inside the crystalline structure. We have performed studies of how Xe atoms dissolved in the UO{sub 2} matrix or precipitated as bubbles impact thermal conductivity, both in bulk UO{sub 2} and in the presence of grain boundaries.

Du, Shiyu [Los Alamos National Laboratory; Andersson, Anders D. [Los Alamos National Laboratory; Germann, Timothy C. [Los Alamos National Laboratory; Stanek, Christopher R. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

470

Pressure transient method for front tracking  

SciTech Connect (OSTI)

A pressure transient technique for tracking the advance of cold water fronts during water flooding and goethermal injection operations has been developed. The technique is based on the concept that the steady state pressure buildup in the reservoir region inside the front can be calculated by a fluid skin factor. By analyzing successive pressure falloff tests, the advance of the front in the reservoir can be monitored. The validity of the methods is demonstrated by application to three numerically simulated data sets, a nonisothermal step-rate injection test, a series of pressure falloffs in a multilayered reservoir, and a series of pressure falloff tests in a water flooded oil reservoir.

Benson, S.M.; Bodvarsson, G.S.

1983-08-01T23:59:59.000Z

471

Marine asset security and tracking (MAST) system  

DOE Patents [OSTI]

Methods and apparatus are described for marine asset security and tracking (MAST). A method includes transmitting identification data, location data and environmental state sensor data from a radio frequency tag. An apparatus includes a radio frequency tag that transmits identification data, location data and environmental state sensor data. Another method includes transmitting identification data and location data from a radio frequency tag using hybrid spread-spectrum modulation. Another apparatus includes a radio frequency tag that transmits both identification data and location data using hybrid spread-spectrum modulation.

Hanson, Gregory Richard (Clinton, TN); Smith, Stephen Fulton (Loudon, TN); Moore, Michael Roy (Corryton, TN); Dobson, Eric Lesley (Charleston, SC); Blair, Jeffrey Scott (Charleston, SC); Duncan, Christopher Allen (Marietta, GA); Lenarduzzi, Roberto (Knoxville, TN)

2008-07-01T23:59:59.000Z

472

CSE: Financial Engineering Track Robbin Tops, SAM  

E-Print Network [OSTI]

CSE: Financial Engineering Track Robbin Tops, SAM robbin.tops@sam.math.ethz.ch CSE: Financial Stochastic Processes: (Brownian Motion, L´evy processes) 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 -2.5 -2 -1-)Differential Equations: (Heat Equation) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 Stochastic

Lang, Annika

473

Turkey Track Wind Farm | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 No revisionEnvReviewNonInvasiveExplorationUT-gTaguspark JumpDetective:Toyo AluminiumCityTullahoma,Turbo DynamicsTrack

474

Floating Robots Track Water Flow With Smartphones  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr Flickr Editor's note: Since the Flickr platformFloating Robots Track

475

Tracking New Coal-Fired Power Plants  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2Topo II: An EnzymePersonalTracking Living Cells(data

476

Tracking New Coal-Fired Power Plants  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2Topo II: An EnzymePersonalTracking Living Cells(data

477

Low-Energy Fusion-Fission Dynamics of Heavy Nuclear Systems  

SciTech Connect (OSTI)

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.

Zagrebaev, Valery [Flerov Laboratory of Nuclear Reaction, JINR, Dubna, 141980, Moscow region (Russian Federation); Greiner, Walter [Frankfurt Institute for Advanced Studies, J.W. Goethe-Universitaet, Frankfurt (Germany)

2006-08-14T23:59:59.000Z

478

Fission Product Transport in TRISO Particle Layers under Operating and Off-Normal Conditions  

SciTech Connect (OSTI)

The objective of this project is to determine the diffusivity and chemical behavior of key fission products (ag, Cs, I. Te, Eu and Sr) through SiC and PyC both thermally, under irradiation, and under stress using FP introduction techniques that avoid the pitfalls of past experiments. The experimental approach is to create thin PyC-SiC couples containing the fission product to be studied embedded in the PyC layer. These samples will then be subjected to high temperature exposures in a vacuum and also to irradiation at high temperature, and last, to irradiation under stress at high temperature. The PyC serves as a host layer, providing a means of placing the fission product close to the SiC without damaging the SiC layer by its introduction or losing the FP during heating. Experimental measurements of grain boundary structure and distribution (EBSD, HRTEM, APT) will be used in the modeling effort to determine the qualitative dependence of FP diffusion coefficients on grain boundary orientation, temperature and stress.

Van der Ven, Anton; Was, Gary; Wang, Lumin; Taheri, Mitra

2014-07-07T23:59:59.000Z

479

Spontaneous fission modes and lifetimes of super-heavy elements in the nuclear density functional theory  

E-Print Network [OSTI]

Lifetimes of super-heavy (SH) nuclei are primarily governed by alpha decay and spontaneous fission (SF). Here we study the competing decay modes of even-even SH isotopes with 108 density functional theory framework capable of describing the competition between nuclear attraction and electrostatic repulsion. The collective mass tensor of the fissioning superfluid nucleus is computed by means of the cranking approximation to the adiabatic time-dependent Hartree-Fock-Bogoliubov approach. Along the path to fission, our calculations allow for the simultaneous breaking of axial and space inversion symmetries; this may result in lowering SF lifetimes by more than seven orders of magnitude in some cases. We predict two competing SF modes: reflection-symmetric and reflection-asymmetric.The shortest-lived SH isotopes decay by SF; they are expected to lie in a narrow corridor formed by $^{280}$Hs, $^{284}$Fl, and $^{284}_{118}$Uuo that separates the regions of SH nuclei synthesized in "cold fusion" and "hot fusion" reactions. The region of long-lived SH nuclei is expected to be centered on $^{294}$Ds with a total half-life of ?1.5 days.

A. Staszczak; A. Baran; W. Nazarewicz

2012-08-06T23:59:59.000Z

480

Statistical Model Analysis of (n,p) Cross Sections and Average Energy For Fission Neutron Spectrum  

SciTech Connect (OSTI)

Investigation of charged particle emission reaction cross sections for fast neutrons is important to both nuclear reactor technology and the understanding of nuclear reaction mechanisms. In particular, the study of (n,p) cross sections is necessary to estimate radiation damage due to hydrogen production, nuclear heating and transmutations in the structural materials of fission and fusion reactors. On the other hand, it is often necessary in practice to evaluate the neutron cross sections of the nuclides for which no experimental data are available.Because of this, we carried out the systematical analysis of known experimental (n,p) and (n,a) cross sections for fast neutrons and observed a systematical regularity in the wide energy interval of 6-20 MeV and for broad mass range of target nuclei. To explain this effect using the compound, pre-equilibrium and direct reaction mechanisms some formulae were deduced. In this paper, in the framework of the statistical model known experimental (n,p) cross sections averaged over the thermal fission neutron spectrum of U-235 are analyzed. It was shown that the experimental data are satisfactorily described by the statistical model. Also, in the case of (n,p) cross sections the effective average neutron energy for fission spectrum of U-235 was found to be around 3 MeV.

Odsuren, M.; Khuukhenkhuu, G. [Nuclear Research Center, National University of Mongolia, Ulaanbaatar (Mongolia)

2011-06-28T23:59:59.000Z