Evaluation of fission product neutron cross sections for JENDL
International Nuclear Information System (INIS)
1984-01-01
The recent activities on the evaluation of fission product (FP) neutron cross sections for JENDL (Japanese Evaluated Nuclear Data Library) are presented briefly. The integral test of JENDL-1 FP cross section file was performed using the CFRMF sample activation data and the STEK sample reactivity data, and the ratio of experiment to calculation was nearly constant for all the samples in the STEK measurement. Therefore, a tentative analysis was performed by applying the correction to the calculated scattering reactivity component. Better agreement with the experiment was obtained after applying this correction in most cases. The evaluation work on the JENDL-2 FP neutron cross sections is now in progress. The improvement of the data evaluation is presented in an itemized form. The JENDL-2 FP file will contain the evaluated data for 100 nuclides from Kr to Tb. The improvement and the future scope of the integral test for JENDL-2 FP data are summarized. (Asami, T.)
Benchmark of neutron production cross sections with Monte Carlo codes
Tsai, Pi-En; Lai, Bo-Lun; Heilbronn, Lawrence H.; Sheu, Rong-Jiun
2018-02-01
Aiming to provide critical information in the fields of heavy ion therapy, radiation shielding in space, and facility design for heavy-ion research accelerators, the physics models in three Monte Carlo simulation codes - PHITS, FLUKA, and MCNP6, were systematically benchmarked with comparisons to fifteen sets of experimental data for neutron production cross sections, which include various combinations of 12C, 20Ne, 40Ar, 84Kr and 132Xe projectiles and natLi, natC, natAl, natCu, and natPb target nuclides at incident energies between 135 MeV/nucleon and 600 MeV/nucleon. For neutron energies above 60% of the specific projectile energy per nucleon, the LAQGMS03.03 in MCNP6, the JQMD/JQMD-2.0 in PHITS, and the RQMD-2.4 in FLUKA all show a better agreement with data in heavy-projectile systems than with light-projectile systems, suggesting that the collective properties of projectile nuclei and nucleon interactions in the nucleus should be considered for light projectiles. For intermediate-energy neutrons whose energies are below the 60% projectile energy per nucleon and above 20 MeV, FLUKA is likely to overestimate the secondary neutron production, while MCNP6 tends towards underestimation. PHITS with JQMD shows a mild tendency for underestimation, but the JQMD-2.0 model with a modified physics description for central collisions generally improves the agreement between data and calculations. For low-energy neutrons (below 20 MeV), which are dominated by the evaporation mechanism, PHITS (which uses GEM linked with JQMD and JQMD-2.0) and FLUKA both tend to overestimate the production cross section, whereas MCNP6 tends to underestimate more systems than to overestimate. For total neutron production cross sections, the trends of the benchmark results over the entire energy range are similar to the trends seen in the dominate energy region. Also, the comparison of GEM coupled with either JQMD or JQMD-2.0 in the PHITS code indicates that the model used to describe the first
Evaluation of the neutron and gamma-ray production cross-sections for 55Mn
International Nuclear Information System (INIS)
Takahashi, H.
1974-11-01
The evaluation of neutron and gamma production cross sections for manganese-55 from 1.0 (10) -5 eV to 20.0 MeV for ENDF/ B-IV is summarized. Included are resonance parameters, neutron cross sections, angular and energy distribution of secondary neutrons, gamma multiplicities and transition probability array, gamma angular and energy distributions, nuclear model calculations, uncertainty estimates of cross sections, and evaluated cross sections. (U.S.)
Curves and tables of neutron cross sections of fission product nuclei in JENDL-3
Energy Technology Data Exchange (ETDEWEB)
Nakagawa, Tsuneo [ed.
1992-06-15
Neutron cross sections of 172 nuclei in the fission product region stored in JENDL-3 are shown in graphs and tables. The evaluation work of these nuclei was made by the Fission Product Nuclear Data Working Group of the Japanese Nuclear Data Committee, in the neutron energy region from 10{sup {minus}5} eV to 20 MeV. Almost of the cross section data reproduced in graphs in this report. The cross section averaged over 38 energy intervals are listed in a table. Shown in order tables are thermal cross sections, resonance integrals, Maxwellian neutron flux average cross sections, fission spectrum average cross sections, 14-MeV cross sections, one group average cross sections in neutron flux of typical types of fission reactors and average cross sections in the 30-keV Maxwellian spectrum.
Curves and tables of neutron cross sections of fission product nuclei in JENDL-3
International Nuclear Information System (INIS)
Nakagawa, Tsuneo
1992-06-01
Neutron cross sections of 172 nuclei in the fission product region stored in JENDL-3 are shown in graphs and tables. The evaluation work of these nuclei was made by the Fission Product Nuclear Data Working Group of the Japanese Nuclear Data Committee, in the neutron energy region from 10 -5 eV to 20 MeV. Almost all the cross section data are reproduced in graphs in this report. The cross section averaged over 38 energy intervals are listed in a table. Shown in other tables are thermal cross sections, resonance integrals, Maxwellian neutron flux average cross sections, fission spectrum average cross sections, 14-MeV cross sections, one group average cross sections in neutron flux of typical types of fission reactors and average cross sections in the 30-keV Maxwellian spectrum. (author)
A neutron detector for measurement of total neutron production cross sections
Energy Technology Data Exchange (ETDEWEB)
Sekharan, K K; Laumer, H; Kern, B D; Gabbard, F [Kentucky Univ., Lexington (USA). Dept. of Physics and Astronomy
1976-03-01
A neutron detector has been constructed and calibrated for the accurate measurement of total neutron production cross sections. The detector consists of a polyethylene sphere of 60 cm diameter in which eight /sup 10/BF/sub 3/ counters have been installed radially. The relative efficiency of this detector has been determined for average neutron energies from 30 keV to 1.5 MeV by counting neutrons from /sup 7/Li(p, n)/sup 7/Be. By adjusting the radial positions of the BF/sub 3/ counters in the polyethylene sphere the efficiency for neutron detection was made nearly constant for this energy range. Measurement of absolute efficiency for the same neutron energy range has been done by counting the neutrons from /sup 51/V(p, n)/sup 51/Cr and /sup 57/Fe(p, n)/sup 57/Co reactions and determining the absolute number of residual nuclei produced during the measurement of neutron yield. Details of absolute efficiency measurements and the use of the detector for determination of neutron production cross sections are given.
A neutron detector for measurement of total neutron production cross sections
International Nuclear Information System (INIS)
Sekharan, K.K.; Laumer, H.; Kern, B.D.; Gabbard, F.
1976-01-01
A neutron detector has been constructed and calibrated for the accurate measurement of total neutron production cross sections. The detector consists of a polyethylene sphere of 60 cm diameter in which eight 10 BF 3 counters have been installed radially. The relative efficiency of this detector has been determined for average neutron energies from 30 keV to 1.5 MeV by counting neutrons from 7 Li(p, n) 7 Be. By adjusting the radial positions of the BF 3 counters in the polyethylene sphere the efficiency for neutron detection was made nearly constant for this energy range. Measurement of absolute efficiency for the same neutron energy range has been done by counting the neutrons from 51 V(p, n) 51 Cr and 57 Fe(p, n) 57 Co reactions and determining the absolute number of residual nuclei produced during the measurement of neutron yield. Details of absolute efficiency measurements and the use of the detector for determination of neutron production cross sections are given. (Auth.)
The evaluated neutron cross sections and resonance integrals of fission products with Z = 57-62
International Nuclear Information System (INIS)
Fedorova, A.F.; Pisanko, Zh.I.; Novoselov, G.M.
1976-01-01
Neutron cross sections at a neutron velocity of V=2200 m/s, and resonance integrals for fission products with Z=57-71 are estimated. In obtaining the recommended values the results of the neutron cross sections and resonance integrals for elements used as references were normalized in accordance with the latest adjusted values. In the course of estimation, preference was given to the more accurate methods for obtaining the measured values and to the more recent investigations
The evaluated neutron cross sections and resonance integrals of fission products with Z=63-71
International Nuclear Information System (INIS)
Fedorova, A.F.; Pisanko, Zh.I.; Novoselov, G.M.
1976-01-01
Neutron cross sections at a neutron velocity of V=2200 m/s, and the resonance integrals for fission products with Z=63-71 are estimated. In obtaining the recommended values the results were normalized of the neutron cross sections and resonance integrals for elements used as references in accordance with the latest adjusted values. In the course of estimation, preference was given to the more accurate measuring methods and the more recent investigations. Scientific publications up to 1975 have been used
Measurement of reaction cross sections of fission products induced by DT neutrons
Energy Technology Data Exchange (ETDEWEB)
Nakano, Daisuke; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan)
1998-03-01
With the view of future application of fusion reactor to incineration of fission products, we have measured the {sup 129}I(n,2n){sup 128}I reaction cross section by DT neutrons with the activation method. The measured cross section was compared with the evaluated nuclear data of JENDL-3.2. From the result, it was confirmed that the evaluation overestimated the cross section by about 20-40%. (author)
International Nuclear Information System (INIS)
Iwamoto, Yosuke; Shigyo, Nobuhiro; Satoh, Daiki
2002-01-01
Neutron-production double-differential cross sections for 870-MeV π + and π - and 2.1-GeV π + mesons incident on iron and lead targets were measured with NE213 liquid scintillators by time-of-flight technique. NE213 liquid scintillators 12.7 cm in diameter and 12.7 cm thick were placed in directions of 15, 30, 60, 90, 120 and 150deg. The typical flight path length was 15 m. Neutron detection efficiencies were derived from the calculation results of SCINFUL and CECIL codes. The experimental results were compared with the JAM code. The double differential cross sections calculated by the JAM code disagree with experimental data at neutron energies below about 30 MeV. JAM overestimates π + -incident neutron-production cross sections in forward angles at neutron energies of 100 to 500 MeV. (author)
Evaluation of neutron and gamma-ray-production cross-section data for lead
International Nuclear Information System (INIS)
Fu, C.Y.; Perey, F.G.
1975-01-01
A survey was made of the available information on neutron and gamma-ray-production cross-section measurements of lead. From these and from relevant nuclear-structure information on the Pb isotopes, recommended neutron cross-section data sets for lead covering the neutron energy range from 0.00001 eV to 20.0 MeV have been prepared. The cross sections are derived from experimental results available to February 1972 and from calculations based on optical-model, DWBA, and Hauser--Feshbach theories. Comparisons which show good agreement between theoretical and experimental values are displayed in a number of graphs. Also presented graphically are smoothed total cross sections, Legendre coefficients for angular distributions, and a representative energy distribution of gamma rays from resonance capture. 15 tables, 36 figures, 104 references
Neutron cross sections: Book of curves
International Nuclear Information System (INIS)
McLane, V.; Dunford, C.L.; Rose, P.F.
1988-01-01
Neuton Cross Sections: Book of Curves represents the fourth edition of what was previously known as BNL-325, Neutron Cross Sections, Volume 2, CURVES. Data is presented only for (i.e., intergrated) reaction cross sections (and related fission parameters) as a function of incident-neutron energy for the energy range 0.01 eV to 200 MeV. For the first time, isometric state production cross sections have been included. 11 refs., 4 figs
International Nuclear Information System (INIS)
Pashchenko, A.B.; Wienke, H.
1998-01-01
This document presents the description of a physical tape containing the basic evaluated nuclear data library of neutron-nucleus interaction cross sections, photon production cross sections and photon-atom interaction cross sections for fusion applications. It is part of the evaluated nuclear data library for fusion applications FENDL-2. The data are available cost-free from the Nuclear Data Section upon request. The data can also be retrieved by the user via online access through international computer networks. (author)
International Nuclear Information System (INIS)
Brenner, D.J.; Prael, R.E.; Little, R.C.
1987-01-01
Realistic simulations of the passage of fast neutrons through tissue require a large quantity of cross-sectional data. What are needed are differential (in particle type, energy and angle) cross sections. A computer code is described which produces such spectra for neutrons above ∼14 MeV incident on light nuclei such as carbon and oxygen. Comparisons have been made with experimental measurements of double-differential secondary charged-particle production on carbon and oxygen at energies from 27 to 60 MeV; they indicate that the model is adequate in this energy range. In order to utilize fully the results of these calculations, they should be incorporated into a neutron transport code. This requires defining a generalized format for describing charged-particle production, putting the calculated results in this format, interfacing the neutron transport code with these data, and charged-particle transport. The design and development of such a program is described. 13 refs., 3 figs
Measurement of neutron and gamma-ray production double differential cross section at KEK
International Nuclear Information System (INIS)
Ishibashi, Kenji
1995-01-01
High energy nuclear radiations were measured for 0.8-3.0 GeV proton induced reactions at KEK. The measurement was carried out to overcome the problems arising from the use of secondary beam line of a quite low incident beam intensity. Digital pulse shape discrimination method was applicable to separation between high energy neutrons and gamma-rays. By the use of a number of scintillators, cross sections were obtained for production of neutrons and gamma-rays. (author)
Gamma-ray production cross sections for MeV neutrons
International Nuclear Information System (INIS)
Kitazawa, Hideo; Harima, Yoshiko; Yamakoshi, Hisao; Sano, Yuji; Kobayashi, Tsuguyuki.
1979-01-01
Gamma-ray production cross section and spectra for 1- to 20-MeV neutrons were theoretically obtained, which were requested for heating calculations, for shielding design calculations, and for material damage estimates. Calculations were carried out for Al, Si, Ca, Fe, Ni, Cu, Nb, Ta, Au, and Pb, using a spin-dependent evaporation model without the parity conservation and including the dipole and quardupole gamma-ray transitions. The results were compared with the experimental data measured in ORNL to confirm the availability of this model in applications. In addition, the effects on the gamma-ray production cross section of the optical potential, level density, yrast level, and radiation width were investigated in detail. The conclusions are: 1) the use of the optical potential which gives the correct total reaction cross section is essential to gamma-ray production calculations, 2) the gamma-ray production cross section is not so sensitive to the choice of level density parameters, 3) the inclusion of yrast levels is necessary in dealing with the competition of the neutron and gamma-ray emissions from highly excited states, and 4) the Brink-Axel type's radiation width is unsuitable to be applied to radiative capture processes. (author)
Neutron cross sections for defect production by high-energy displacement cascades in copper
International Nuclear Information System (INIS)
Heinisch, H.L.; Mann, F.M.
1983-08-01
Defect production cross sections for copper have been devised, based on computer simulations of displacement cascades. One thousand cascades ranging in energy from 200 eV to 200 keV were generated with the MARLOWE computer code. The cascades were subjected to a semi-empirical cascade quenching procedure and to short-term annealing with the ALSOME computer code. Functions were fitted to the numbers of defects produced as a function of primary knock-on atom (PKA) damage energy for the following defect types: 1) the total number of point defects after quenching and after short-term annealing, 2) the numbers of free interstitials and free vacancies after shortterm annealing, and 3) the numbers and sizes of vacancy and interstitial clusters after shortterm annealing. In addition, a function describing the number of distinct damage regions (lobes) per cascade was fitted to results of a graphical analysis of the cascade configurations. The defect production functions have been folded into PKA spectra using the NJOY nuclear data processing code system with ENDF/B-V nuclear data to yield neutron cross sections for defect production in copper. The free vacancy cross section displays much less variation with neutron energy than the cross sections for damage energy or total point defects
Neutron cross sections for defect production by high energy displacement cascades in copper
International Nuclear Information System (INIS)
Heinisch, H.L.; Mann, F.M.
1984-01-01
Defect production cross sections for copper have been devised, based on computer simulations of displacement cascades. One thousand cascades ranging in energy from 200 eV to 200 keV were generated with the MARLOWE computer code. The cascades were subjected to a semi-empirical cascade quenching procedure and to short-term annealing with the ALSOME computer code. Functions were fitted to the numbers of defects produced as a function of primary knock-on atom (PKA) damage energy for the following defect types: 1) the total number of point defects after quenching and after short-term annealing, 2) the numbers of free interstitials and free vacancies after short-term annealing, and 3) the numbers and sizes of vacancy and interstitial clusters after short-term annealing. In addition, a function describing the number of distinct damage regions (lobes) per cascade was fitted to results of a graphical analysis of the cascade configurations. The defect production functions have been folded into PKA spectra using the NJOY nuclear data processing code system with ENDF/B-V nuclear data to yield neutron cross sections for defect production in copper. The free vacancy cross section displays much less variation with neutron energy than the cross sections for damage energy or total point defects. (orig.)
NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION
International Nuclear Information System (INIS)
OH, S.Y.; CHANG, J.; MUGHABGHAB, S.
2000-01-01
Neutron cross section evaluations of the fission-product isotopes, 95 Mo, 99 Tc, 101 Ru, 103 Rh, 105 Pd, 109 Ag, 131 Xe, 133 Cs, 141 Pr, 141 Nd, 147 Sm, 149 Sm, 150 Sm, 151 Sm, 152 Sm, 153 Eu, 155 Gd, and 157 Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of 155 Gd and 157 Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations
NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION
Energy Technology Data Exchange (ETDEWEB)
OH,S.Y.; CHANG,J.; MUGHABGHAB,S.
2000-05-11
Neutron cross section evaluations of the fission-product isotopes, {sup 95}Mo, {sup 99}Tc, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, {sup 141}Nd, {sup 147}Sm, {sup 149}Sm, {sup 150}Sm, {sup 151}Sm, {sup 152}Sm, {sup 153}Eu, {sup 155}Gd, and {sup 157}Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of {sup 155}Gd and {sup 157}Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations.
Heinitz, S; Schumann, D; Dressler, R; Kivel, N; Guerrero, C; Köster, U; Tessler, M; Paul, M; Halfon, S
2015-01-01
The knowledge of the neutron capture cross sections of s-process branching point isotopes represents a basic requirement for the understanding of star evolution. Since such branching point isotopes are by definition radioactive, the measurement of their cross sections from thermal to stellar energies becomes a challenging task. Considerable amounts of material have to be produced, representing a significant radioactive hazard. We report here on the production and separation of 3.5 mg 171Tm from 240 mg 170Er2O3 and 72 µg 147Pm from 100 mg 146Nd2O3 irradiated at the ILL high flux reactor. Thin targets were prepared with high chemical and radioisotopic purity suitable for neutron capture measurements at n_TOF CERN and the SARAF-LiLiT facility.
γ production and neutron inelastic scattering cross sections for 76Ge
Rouki, C.; Domula, A. R.; Drohé, J. C.; Koning, A. J.; Plompen, A. J. M.; Zuber, K.
2013-11-01
The 2040.7-keV γ ray from the 69th excited state of 76Ge was investigated in the interest of Ge-based double-β-decay experiments like the Germanium Detector Array (GERDA) experiment. The predicted transition could interfere with valid 0νββ events at 2039.0 keV, creating false signals in large-volume 76Ge enriched detectors. The measurement was performed with the Gamma Array for Inelastic Neutron Scattering (GAINS) at the Geel Electron Linear Accelerator (GELINA) white neutron source, using the (n,n'γ) technique and focusing on the strongest γ rays originating from the level. Upper limits obtained for the production cross section of the 2040.7-keV γ ray showed no possible influence on GERDA data. Additional analysis of the data yielded high-resolution cross sections for the low-lying states of 76Ge and related γ rays, improving the accuracy and extending existing data for five transitions and five levels. The inelastic scattering cross section for 76Ge was determined for incident neutron energies up to 2.23 MeV, significantly increasing the energy range for which experimental data are available. Comparisons with model calculations using the talys code are presented indicating that accounting for the recently established asymmetric rotor structure should lead to an improved description of the data.
International Nuclear Information System (INIS)
Pashchenko, A.B.; Wienke, H.; Ganesan, S.; McLaughlin, P.K.
1996-01-01
This document presents the description of a physical tape containing the basic evaluated nuclear data library of neutron nuclear interaction cross-sections and photon production cross-sections and photon-atom interaction cross-sections for fusion applications. It is part of FENDL, the evaluated nuclear data library for fusion applications. The nuclear data are available cost-free for distribution to interested scientists upon request. The data can also be retrieved by the user via online access through international computer networks. (author). 11 refs, 1 tab
International Nuclear Information System (INIS)
Savin, M.V.; Nefedov, Yu.Ya; Livke, A.V.; Zvenigorodskij, A.G.
2001-01-01
Experimental data on the total gamma-ray production cross-sections for inelastic interaction of fast neutrons with iron nuclei were analysed. The total gamma-ray production cross-sections, grouped according to E γ , were evaluated in the neutron energy range 0.5-19 MeV. The statistical spline approximation method was used to evaluate the experimental data. Evaluated data stored in the ENDF, JENDL, BROND, and other libraries on gamma-ray production spectra and cross-sections for inelastic interaction of fast neutrons with iron nuclei, were analysed. (author)
Neutron cross sections for fusion
International Nuclear Information System (INIS)
Haight, R.C.
1979-10-01
First generation fusion reactors will most likely be based on the 3 H(d,n) 4 He reaction, which produces 14-MeV neutrons. In these reactors, both the number of neutrons and the average neutron energy will be significantly higher than for fission reactors of the same power. Accurate neutron cross section data are therefore of great importance. They are needed in present conceptual designs to calculate neutron transport, energy deposition, nuclear transmutation including tritium breeding and activation, and radiation damage. They are also needed for the interpretation of radiation damage experiments, some of which use neutrons up to 40 MeV. In addition, certain diagnostic measurements of plasma experiments require nuclear cross sections. The quality of currently available data for these applications will be reviewed and current experimental programs will be outlined. The utility of nuclear models to provide these data also will be discussed. 65 references
International Nuclear Information System (INIS)
Kerveno, M.; Haddad, F.; Eudes, Ph.; Kirchner, T.; Lebrun, C.; Slypen, I.; Meulders, J.P.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Louvel, M.; Lefebvres, F.; Hilaire, S.; Koning, A.J.
2002-01-01
Double differential hydrogen isotope production cross sections have been extracted in 62.7 MeV neutron induced reactions on a lead target. The angular distribution was measured at eight angles from 20 deg. to 160 deg. allowing the extraction of angle-differential, energy differential, and total production cross sections. A first set of comparisons with several theoretical calculations is also presented
Determination of Unknown Neutron Cross Sections for the Production of Medical Isotopes
Energy Technology Data Exchange (ETDEWEB)
Stephen E. Binney
2004-04-09
Calculational assessment and experimental verification of certain neutron cross sections that are related to widely needed new medical isotopes. Experiments were performed at the Oregon State University TRIGA Reactor and the High Flux Irradiation Reactor at Oak Ridge National Laboratory.
Evaluation and Compilation of Neutron Activation Cross Sections for Medical Isotope Production
International Nuclear Information System (INIS)
Binney, Stephen E.
2004-01-01
Calculational assessment and experimental verification of certain neutron cross sections that are related to widely needed new medical isotopes. Experiments were performed at the Oregon State University TRIGA Reactor and the High Flux Irradiation Reactor at Oak Ridge National Laboratory
[Fast neutron cross section measurements
International Nuclear Information System (INIS)
Knoll, G.F.
1992-01-01
From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ''clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ''data production'' phase
Measurements of fission cross-sections and of neutron production rates
International Nuclear Information System (INIS)
Billaud, P.; Clair, C.; Gaudin, M.; Genin, R.; Joly, R.; Leroy, J.L.; Michaudon, A.; Ouvry, J.; Signarbieux, C.; Vendryes, G.
1958-01-01
a) Measurements of neutron induced fission cross-sections in the low energy region. The variation of the fission cross sections of several fissile isotopes has been measured and analysed, for neutron energies below 0,025 eV. The monochromator was a crystal spectrometer used in conjunction with a mechanical velocity selector removing higher order Bragg reflections. The fissile material was laid down on the plates of a fission chamber by painting technic. An ionization chamber, having its plates coated with thin 10 B layers, was used as the neutron flux monitor. b) Measurement of the fission cross section of 235 U. We intend to measure the variation of the neutron induced fission cross section of 235 U over the neutron energy range from 1 keV by the time of flight method. The neutron source is the uranium target of a pulsed 28 MeV electron linear accelerator. The detector is a large fission chamber, with parallel plates, containing about 10 g of 235 U (20 deposits of 25 cm diameter). The relative fission data were corrected for the neutron spectrum measured with a set of BF 3 proportional counters. c) Mean number ν of neutrons emitted in neutron induced fission. We measured the value of ν for several fissile isotopes in the case of fission induced by 14 MeV neutrons. The 14 MeV neutrons were produced by D (t, n) α reaction by means of a 300 kV Cockcroft Walton generator. (author) [fr
Neutron cross sections of 28 fission product nuclides adopted in JENDL-1
International Nuclear Information System (INIS)
Kikuchi, Yasuyuki; Nakagawa, Tsuneo; Igarasi, Sin-iti; Matsunobu, Hiroyuki; Kawai, Masayoshi; Iijima, Shungo.
1981-02-01
This is the final report concerning the evaluated neutron cross sections of 28 fission product nuclides adopted in the first version of Japanese Evaluated Nuclear Data Library (JENDL-1). These 28 nuclides were selected as being most important for fast reactor calculations, and are 90 Sr, 93 Zr, 95 Mo, 97 Mo, 99 Tc, 101 Ru, 102 Ru, 103 Rh, 104 Ru, 105 Pd, 106 Ru, 107 Pd, 109 Ag, 129 I, 131 Xe, 133 Cs, 135 Cs, 137 Cs, 143 Nd, 144 Ce, 144 Nd, 145 Nd, 147 Pm, 147 Sm, 149 Sm, 151 Sm, 153 Eu and 155 Eu. The status of the experimental data was reviewed over the whole energy range. The present evaluation was performed on the basis of the measured data with the aid of theoretical calculations. The optical and statical models were used for evaluation of the smooth cross sections. An improved method was developed in treating the multilevel Breit-Wigner formula for the resonance region. Various physical parameters and the level schemes, adopted in the present work are discussed by comparing with those used in the other evaluations such as ENDF/B-IV, CEA, CNEN-2 and RCN-2. Furthermore, the evaluation method and results are described in detail for each nuclide. The evaluated total, capture and inelastic scattering cross sections are compared with the other evaluated data and some recent measured data. Some problems of the present work are pointed out and ways of their improvement are suggested. (author)
International Nuclear Information System (INIS)
Mori, Takamasa; Nakagawa, Masayuki; Kaneko, Kunio.
1996-05-01
A code system has been developed to produce neutron cross section libraries for the MVP continuous energy Monte Carlo code from an evaluated nuclear data library in the ENDF format. The code system consists of 9 computer codes, and can process nuclear data in the latest ENDF-6 format. By using the present system, MVP neutron cross section libraries for important nuclides in reactor core analyses, shielding and fusion neutronics calculations have been prepared from JENDL-3.1, JENDL-3.2, JENDL-FUSION file and ENDF/B-VI data bases. This report describes the format of MVP neutron cross section library, the details of each code in the code system and how to use them. (author)
Energy Technology Data Exchange (ETDEWEB)
Mori, Takamasa; Nakagawa, Masayuki [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Kaneko, Kunio
1996-05-01
A code system has been developed to produce neutron cross section libraries for the MVP continuous energy Monte Carlo code from an evaluated nuclear data library in the ENDF format. The code system consists of 9 computer codes, and can process nuclear data in the latest ENDF-6 format. By using the present system, MVP neutron cross section libraries for important nuclides in reactor core analyses, shielding and fusion neutronics calculations have been prepared from JENDL-3.1, JENDL-3.2, JENDL-FUSION file and ENDF/B-VI data bases. This report describes the format of MVP neutron cross section library, the details of each code in the code system and how to use them. (author).
International Nuclear Information System (INIS)
Meier, M.M.; Amian, W.B.; Clark, D.A.; Goulding, C.A.; McClelland, J.B.; Morgan, G.L.; Moss, C.E.
1989-03-01
We have measured differential (P,ξn) cross sections, d 2 σ/dΩdE/sub n/, from thin targets and absolute neutron yields from stopping-length targets at angles of 7.5/degree/, 30/degree/, 60/degree/, and 150/degree/, for the 113--MeV proton bombardment of elemental beryllium, carbon, aluminum, iron, and depleted uranium. Additional cross-section measurements are reported for oxygen, tungsten, and lead. We used time-of-flight techniques to identify and discriminate against backgrounds and to determine the neutron energy spectrum. Comparison of the experimental data with intranuclear-cascade evaporation-model calculations with the code HETC showed discrepancies as high as a factor of 7 in the differential cross sections. These discrepancies in the differential cross sections make it possible to identify some of the good agreement seen in the stopping-length yield comparisons as fortuitous cancellation of incorrect production estimates in different energy regimes. 13 refs., 20 figs., 4 tabs
Covariance Evaluation Methodology for Neutron Cross Sections
Energy Technology Data Exchange (ETDEWEB)
Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.
2008-09-01
We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.
Neutron cross section libraries for analysis of fusion neutronics experiments
International Nuclear Information System (INIS)
Kosako, Kazuaki; Oyama, Yukio; Maekawa, Hiroshi; Nakamura, Tomoo
1988-03-01
We have prepared two computer code systems producing neutron cross section libraries to analyse fusion neutronics experiments. First system produces the neutron cross section library in ANISN format, i.e., the multi-group constants in group independent format. This library can be obtained by using the multi-group constant processing code system MACS-N and the ANISN format cross section compiling code CROKAS. Second system is for the continuous energy cross section library for the MCNP code. This library can be obtained by the nuclear data processing system NJOY which generates pointwise energy cross sections and the cross section compiling code MACROS for the MCNP library. In this report, we describe the production procedures for both types of the cross section libraries, and show six libraries with different conditions in ANISN format and a library for the MCNP code. (author)
[Fast neutron cross section measurements
International Nuclear Information System (INIS)
1991-01-01
In the 14 MeV Neutron Laboratory, we have continued the development of a facility that is now the only one of its kind in operation in the United States. We have refined the klystron bunching system described in last year's report to the point that 1.2 nanosecond pulses have been directly measured. We have tested the pulse shape discrimination capability of our primary NE 213 neutron detector. We have converted the RF sweeper section of the beamline to a frequency of 1 MHz to replace the function of the high voltage pulser described in last year's report which proved to be difficult to maintain and unreliable in its operation. We have also overcome several other significant experimental difficulties, including a major problem with a vacuum leak in the main accelerator column. We have completed additional testing to prove the remainder of the generation and measurement systems, but overcoming some of these experimental difficulties has delayed the start of actual data taking. We are now in a position to begin our first series of ring geometry elastic scattering measurements, and these will be underway before the end of the current contract year. As part of our longer term planning, we are continuing the conceptual analysis of several schemes to improve the intensity of our current pulsed beam. These include the provision of a duoplasmatron ion source and/or the provision of preacceleration bunching. Additional details are given later in this report. A series of measurements were carried out at the Tandem Dynamatron Facility involving the irradiation of a series of yttrium foils and the determination of activation cross sections using absolute counting techniques. The experimental work has been completed, and final analysis of the cross section data will be completed within several months
Measurement of secondary gamma-ray production cross sections of vanadium induced by D-T neutrons
International Nuclear Information System (INIS)
Kondo, Tetsuo; Murata, Isao; Takahashi, Akito
1999-01-01
The secondary gamma-ray production cross sections of vanadium induced by D-T neutrons have been measured. The experimental values were compared with the theoretical calculation results by SINCROS-II and the evaluation result based on experimental data compiled by Simakov. The calculation results supported our data, while Simakov's evaluation did not agree with the present result very well. (author)
International Nuclear Information System (INIS)
Patrick, B.H.; Sowerby, M.G.; Wilkins, C.G.; Russen, L.C.
1990-01-01
The cross sections for the production of isomeric states in the reactions 179 Hf(n,2n) 178m2 Hf, 180 Hf(n,2n) 179m2 Hf, 179 Hf(n,n') 179m2 Hf with 14 MeV neutrons have been measured and compared with the theoretical ones. 4 refs, 3 figs, 4 tabs
International Nuclear Information System (INIS)
Murata, Isao; Yamamoto, Junji; Takahashi, Akito
1988-01-01
Energy differential cross sections for the gamma-rays produced from the (n,xγ) reactions by 14 MeV neutrons were measured in the gamma-ray energy range from 700 keV to 10 MeV using an NaI spectrometer. Results were obtained for the 8 natural elements; C, Al, Si, Cr, Fe, Ni, Cu and Mo. For prominent discrete gamma-rays in the differential cross sections, the production cross sections were determined by measuring angular distributions with a Ge detector. The gamma-ray energy covered the range between 500 and 3000 keV. The energy distributions have been compared with the differential cross sections evaluated in the nuclear data files of JENDL-3T, ENDL and ENDF/B-IV. The evaluations in JENDL-3T agreed fairly well with the measurements concerning the continuum energy spectra for secondary photons. Discrepancies appeared, however, for Si, Cr and Ni at the energies where the discrete gamma-rays were dominant. The ENDL evaluations were largely deviated from the experimental data. The production cross sections for the discrete gamma-rays in ENDL and ENDF/B-IV were available for the comparison with some of the measured cross sections. Results are presented for C, Al and Si. (author)
International Nuclear Information System (INIS)
Smith, D.L.; Meadows, J.W.; Greenwood, L.R.
1990-01-01
Integral neutron-reaction cross sections have been measured, relative to the U-238 neutron fission cross-section standard, for 27 reactions which are of contemporary interest in various nuclear applications (e.g., fast-neutron dosimetry, neutron radiation damage and the production of long-lived activities which affect nuclear waste disposal). The neutron radiation field employed in this study was produced by bombarding a thick Be-metal target with 7-MeV deuterons from an accelerator. The experimental results are reported along with detailed information on the associated measurement uncertainties and their correlations. These data are also compared with corresponding calculated values, based on contemporary knowledge of the differential cross sections and of the Be(d,n) neutron spectrum. Some conclusions are reached on the utility of this procedure for neutron-reaction data testing
Helium production cross section Measurement of Pb and Sn for 14.9 MeV neutrons
Energy Technology Data Exchange (ETDEWEB)
Takao, Yoshiyuki; Fujimoto, Toshihiro; Ozaki, Shuji; Muramasu, Masatomo; Nakashima, Hideki [Kyushu Univ., Fukuoka (Japan); Kanda, Yukinori; Ikeda, Yujiro
1998-03-01
Helium production cross sections of lead and tin for 14.9 MeV neutrons were measured by helium accumulation method. Lead and tin samples were irradiated with FNS, an intense d-T neutron source of JAERI. The amount of helium produced in the samples by the neutron irradiation was measured with the Helium Atoms Measurement System (HAMS) at Kyushu University. As the samples contained a small amount of helium because of their small helium production cross sections at 14.9 MeV, the samples were evaporated by radiation from a tungsten filament to decrease background gases at helium measurement. Uncertainties of the present results were less than {+-}4.4%. The results were compared with other experimental data in the literature and also compared with the evaluated values in JENDL-3.2. (author)
International Nuclear Information System (INIS)
Bernnat, W.; Keinert, J.; Mattes, M.
2004-01-01
For the calculation of neutron spectra in cold and super thermal sources scattering laws for a variety of liquid and solid cyrogenic materials were evaluated and prepared for use in deterministic and Monte Carlo transport calculations. For moderator materials like liquid and solid H 2 O, liquid He, liquid D 2 O, liquid and solid H 2 and D 2 , solid CH 4 and structure materials such as Al, Bi, Pb, ZrHx, and graphite scattering law data and cross sections are available. The evaluated data were validated by comparison with measured cross sections and comparison of measured and calculated neutron spectra as far as available. Further applications are the calculation of production and transport and storing of ultra cold neutrons (UCN) in different UCN sources. The data structures of the evaluated data are prepared for the common S N -transport codes and the Monte Carlo Code MCNP. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Bernnat, W.; Keinert, J.; Mattes, M. [Inst. for Nuclear Energy and Energy Systems, Univ. of Stuttgart, Stuttgart (Germany)
2004-03-01
For the calculation of neutron spectra in cold and super thermal sources scattering laws for a variety of liquid and solid cyrogenic materials were evaluated and prepared for use in deterministic and Monte Carlo transport calculations. For moderator materials like liquid and solid H{sub 2}O, liquid He, liquid D{sub 2}O, liquid and solid H{sub 2} and D{sub 2}, solid CH{sub 4} and structure materials such as Al, Bi, Pb, ZrHx, and graphite scattering law data and cross sections are available. The evaluated data were validated by comparison with measured cross sections and comparison of measured and calculated neutron spectra as far as available. Further applications are the calculation of production and transport and storing of ultra cold neutrons (UCN) in different UCN sources. The data structures of the evaluated data are prepared for the common S{sub N}-transport codes and the Monte Carlo Code MCNP. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Takao, Yoshiyuki; Kanda, Yukinori; Nagae, Koji; Fujimoto, Toshihiro [Kyushu Univ., Fukuoka (Japan); Ikeda, Yujiro
1997-03-01
Helium production cross sections of Iron were measured by helium accumulation method for neutron energies from 13.5 to 14.9 MeV. Iron samples were irradiated with FNS, an intense d-T neutron source of JAERI. As the neutron energy varies according to the emission angle at the neutron source, the samples were set around the neutron source and were irradiated by neutrons of different energy depending on each sample position. The amount of helium produced in a sample was measured by Helium Atoms Measurement System at Kyushu University. The results of this work are in good agreement with other experimental data in the literature and also compared with the evaluated values in JENDL-3. (author)
Neutron Cross Sections for Aluminium
Energy Technology Data Exchange (ETDEWEB)
Forsberg, Leif
1963-08-15
Total, elastic, inelastic, (n, 2n), (n, {alpha}), (n, p), and (n, {gamma}) cross sections for aluminium have been compiled from thermal to 100 MeV based upon literature search and theoretical interpolations and estimates. Differential elastic cross sections in the centre of mass system are represented by the Legendre coefficients. This method was chosen in order to obtain the best description of the energy dependence of the anisotropy.
Measurement of thermal neutron capture cross section
International Nuclear Information System (INIS)
Huang Xiaolong; Han Xiaogang; Yu Weixiang; Lu Hanlin; Zhao Wenrong
2001-01-01
The thermal neutron capture cross sections of 71 Ga(n, γ) 72 Ga, 94 Zr(n, γ) 95 Zr and 191 Ir(n, γ) 192 Ir m1+g,m2 reactions were measured by using activation method and compared with other measured data. Meanwhile the half-life of 72 Ga was also measured. The samples were irradiated with the neutron in the thermal column of heavy water reactor of China Institute of Atomic Energy. The activities of the reaction products were measured by well-calibrated Ge(Li) detector
Energy Technology Data Exchange (ETDEWEB)
Heinitz, Stephan; Maugeri, Emilio A.; Schumann, Dorothea; Dressler, Rugard; Kivel, Niko [Paul Scherrer Institute, Villigen (Switzerland); Guerrero, Carlos [Sevilla Univ. (Spain); Koester, Ullrich [Institut Laue-Langevin, Grenoble (France); Tessler, Moshe; Paul, Michael [Hebrew Univ. of Jerusalem (Israel); Halfon, Shlomi [Soreq Nuclear Research Center, Yavne (Israel); Collaboration: nTOF Collaboration
2017-07-01
The knowledge of the neutron capture cross sections of s-process branching point isotopes represents a basic requirement for the understanding of star evolution. Since such branching point isotopes are by definition radioactive, the measurement of their cross sections from thermal to stellar energies becomes a challenging task. Considerable amounts of material have to be produced, representing a significant radioactive hazard. We report here on the production and separation of 3.5 mg {sup 171}Tm from 240 mg {sup 170}Er{sub 2}O{sub 3} and 72 μg {sup 147}Pm from 100 mg {sup 146}Nd{sub 2}O{sub 3} irradiated at the ILL high flux reactor. Thin targets were prepared with high chemical and radioisotopic purity suitable for neutron capture measurements at nTOF CERN and the SARAF-LiLiT facility.
Curves and tables of neutron cross sections
International Nuclear Information System (INIS)
Nakagawa, Tsuneo; Asami, Tetsuo; Yoshida, Tadashi
1990-07-01
Neutron cross-section curves from the Japanese Evaluated Nuclear Data Library version 3, JENDL-3, are presented in both graphical and tabular form for users in a wide range of application areas in the nuclear energy field. The contents cover cross sections for all the main reactions induced by neutrons with an energy below 20 MeV including; total, elastic scattering, capture, and fission, (n,n'), (n,2n), (n,3n), (n,α), (n,p) reactions. The 2200 m/s cross-section values, resonance integrals, and Maxwellian- and fission-spectrum averaged cross sections are also tabulated. (author)
Measurements of neutron capture cross sections
International Nuclear Information System (INIS)
Nakajima, Yutaka
1984-01-01
A review of measurement techniques for the neutron capture cross sections is presented. Sell transmission method, activation method, and prompt gamma-ray detection method are described using examples of capture cross section measurements. The capture cross section of 238 U measured by three different prompt gamma-ray detection methods (large liquid scintillator, Moxon-Rae detector, and pulse height weighting method) are compared and their discrepancies are resolved. A method how to derive the covariance is described. (author)
International Nuclear Information System (INIS)
Kunieda, Satoshi; Watanabe, Takehito; Shigyo, Nobuhiro; Ishibashi, Kenji; Satoh, Daiki; Nakamura, Takashi; Haight, Robert C.
2004-01-01
The inclusive measurements of neutron-incident neutron-production double-differential cross sections in intermediate energy range is now being carried out. Spallation neutrons are used as incident particles. As a part of this, the experiment was performed by using of NE213 liquid organic scintillators to detect outgoing-neutrons. Incident-neutron energy was determined by time-of-flight technique, and outgoing-neutron energy spectrum was derived by unfolding light-output spectrum of NE213 with response functions calculated by SCINFUL-R. Preliminary cross sections were obtained up to about 100 MeV, and were compared with calculations by the GNASH code. It is hoped to get pure measurements by using measured response functions for our detectors used in this study. (author)
Neutron cross section measurements for the Fast Breeder Program
International Nuclear Information System (INIS)
Block, R.C.
1979-06-01
This research was concerned with the measurement of neutron cross sections of importance to the Fast Breeder Reactor. The capture and total cross sections of fission products ( 101 102 104 Ru, 143 145 Nd, 149 Sm, 95 97 Mo, Cs, Pr, Pd, 107 Pd, 99 Tc) and tag gases (Kr, 78 80 Kr) were measured up to 100 keV. Filtered neutron beams were used to measure the capture cross section of 238 U (with an Fe filter) and the total cross section of Na (with a Na filter). A radioactive neutron capture detector was developed. A list of publications is included
Neutron capture cross section of $^{93}$Zr
We propose to measure the neutron capture cross section of the radioactive isotope $^{93}$Zr. This project aims at the substantial improvement of existing results for applications in nuclear astrophysics and emerging nuclear technologies. In particular, the superior quality of the data that can be obtained at n_TOF will allow on one side a better characterization of s-process nucleosynthesis and on the other side a more accurate material balance in systems for transmutation of nuclear waste, given that this radioactive isotope is widely present in fission products.
Total neutron cross section of lead
International Nuclear Information System (INIS)
Kanda, K.; Aizawa, O.
1976-01-01
The total thermal-neutron cross section of natural lead under various physical conditions was measured by the transmission method. It became clear that the total cross section at room temperature previously reported is lower than the present data. The total cross section at 400, 500, and 600 0 C, above the melting point of lead, 327 0 C, was also measured, and the changes in the cross section as a function of temperature were examined, especially near and below the melting point. The data obtained for the randomly oriented polycrystalline state at room temperature were in reasonable agreement with the theoretical values calculated by the THRUSH and UNCLE-TOM codes
Asres, Yihunie Hibstie; Mathuthu, Manny; Birhane, Marelgn Derso
2018-04-22
This study provides current evidence about cross-section production processes in the theoretical and experimental results of neutron induced reaction of uranium isotope on projectile energy range of 1-100 MeV in order to improve the reliability of nuclear stimulation. In such fission reactions of 235 U within nuclear reactors, much amount of energy would be released as a product that able to satisfy the needs of energy to the world wide without polluting processes as compared to other sources. The main objective of this work is to transform a related knowledge in the neutron-induced fission reactions on 235 U through describing, analyzing and interpreting the theoretical results of the cross sections obtained from computer code COMPLET by comparing with the experimental data obtained from EXFOR. The cross section value of 235 U(n,2n) 234 U, 235 U(n,3n) 233 U, 235 U(n,γ) 236 U, 235 U(n,f) are obtained using computer code COMPLET and the corresponding experimental values were browsed by EXFOR, IAEA. The theoretical results are compared with the experimental data taken from EXFOR Data Bank. Computer code COMPLET has been used for the analysis with the same set of input parameters and the graphs were plotted by the help of spreadsheet & Origin-8 software. The quantification of uncertainties stemming from both experimental data and computer code calculation plays a significant role in the final evaluated results. The calculated results for total cross sections were compared with the experimental data taken from EXFOR in the literature, and good agreement was found between the experimental and theoretical data. This comparison of the calculated data was analyzed and interpreted with tabulation and graphical descriptions, and the results were briefly discussed within the text of this research work. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.
International Nuclear Information System (INIS)
Hirasawa, Yoshitaka; Baba, Mamoru; Nauchi, Yasushi
2000-01-01
We have performed the measurements of double differential charged-particle production cross section ((n,xz)DDXs) of iron and nickel for 55, 65, 75 MeV neutrons using the 7 Li(p,n) quasi-monoenergetic source of TIARA(Takasaki Ion Accelerator for Radiation Application). The experimental data were compared with the LA-150 data library, which agreed generally with the present data. KERMA(Kinetic Energy Released in MAtter) coefficients(of Fe) were deduced from the experimental data and compared with the integral measurement and calculations by the LA-150 data library. (author)
Fast-neutron capture cross sections for the most important fission-product nuclei
International Nuclear Information System (INIS)
Gruppelaar, H.
1982-01-01
The main activity of the fission-product (FP) Working Group was the discussion of the current status of neutron capture knowledge of the most important FP nuclides, including the formulation of recommendations toward improved understanding. The results of the discussion are summarized. General conclusions and recommendations are given. The status of integral data is summarized by R. Anderl; and nuclear models and calculations are reviewed by D. Gardner and G. Reffo
Validation of evaluated neutron standard cross sections
International Nuclear Information System (INIS)
Badikov, S.; Golashvili, T.
2008-01-01
Some steps of the validation and verification of the new version of the evaluated neutron standard cross sections were carried out. In particular: -) the evaluated covariance data was checked for physical consistency, -) energy-dependent evaluated cross-sections were tested in most important neutron benchmark field - 252 Cf spontaneous fission neutron field, -) a procedure of folding differential standard neutron data in group representation for preparation of specialized libraries of the neutron standards was verified. The results of the validation and verification of the neutron standards can be summarized as follows: a) the covariance data of the evaluated neutron standards is physically consistent since all the covariance matrices of the evaluated cross sections are positive definite, b) the 252 Cf spectrum averaged standard cross-sections are in agreement with the evaluated integral data (except for 197 Au(n,γ) reaction), c) a procedure of folding differential standard neutron data in group representation was tested, as a result a specialized library of neutron standards in the ABBN 28-group structure was prepared for use in reactor applications. (authors)
Neutron capture cross-section of fission products in the European activation file EAF-3
International Nuclear Information System (INIS)
Kopecky, J.; Delfini, M.G.; Kamp, H.A.J. van der; Gruppelaar, H.; Nierop, D.
1992-05-01
This paper contains a description of the work performed to extend and revise the neutron capture data in the European Activation File (EAF-3) with emphasis on nuclides in the fission-product mass range. The starter was the EAF-1 data file from 1989. The present version, EAF/NG-3, contains (n,γ) excitation functions for all nuclides (729 targets) with half-lives exceeding 1/2 day in the mass range from H-1 to Cm-248. The data file is equipped with a preliminary uncertainty file, that will be improved in the near future. (author). 19 refs.; 5 figs.; 3 tabs
Evaluation methods for neutron cross section standards
International Nuclear Information System (INIS)
Bhat, M.R.
1980-01-01
Methods used to evaluate the neutron cross section standards are reviewed and their relative merits, assessed. These include phase-shift analysis, R-matrix fit, and a number of other methods by Poenitz, Bhat, Kon'shin and the Bayesian or generalized least-squares procedures. The problems involved in adopting these methods for future cross section standards evaluations are considered, and the prospects for their use, discussed. 115 references, 5 figures, 3 tables
Precise measurements of neutron capture cross sections for FP
International Nuclear Information System (INIS)
Nakamura, Shoji; Harada, Hideo; Katoh, Toshio
2000-01-01
The thermal neutron capture cross sections (σ 0 ) and the resonance integrals (I 0 ) of some fission products (FP), such as 137 Cs, 90 Sr, 99 Tc, 129 I and 135 Cs, were measured by the activation and γ-ray spectroscopic methods. Moreover, the cross section measurements were done for other FP elements, such as 127 I, 133 Cs and 134 Cs. This paper provides the summary of the FP cross section measurements, which have been performed by authors. (author)
Evaluation of tritium production cross-section for neutron-interaction with 7Li
International Nuclear Information System (INIS)
Yu Baosheng; Cai Dunjiu
1987-01-01
The 7 Li(n, n't) α reaction cross-section has been evaluated and recommended. These experimental data were selected up to the end of 1986, in which main microscopic nuclear data and benchmark measurements were included. These data are retrieved from EXFOR master files of International Atomic Energy Agency, and new information is added in which IAE (the Chinese Institute of Atomic Energy) experimental results is considered
Differential α-production cross sections of iron and nickel for 4.3 to 14.1 MeV Neutrons
International Nuclear Information System (INIS)
Baba, Mamoru; Ito, Nobuo; Matsuyama, Isamu
1994-01-01
The cross section data for neutron-induced α-production are of prime importance in the evaluation of the radiation damage and nuclear heating in fusion and fast reactors. For the evaluation, energy and angular doubly differential cross sections are also required to calculate primary knock-on atom spectra. However, the experimental (n, xα) data are few and discrepant, therefore, the new experimental data are required urgently to improve the accuracy of the (n, xα) cross section data. The authors have measured the double differential (n, xα) cross sections of Fe and Ni in the neutron energy range of 4.3-14.1 MeV using a specially developed gridded ionization chamber. The present work was undertaken as a part of IAEA Coordinated Research Program for neutron-induced He production cross sections. The gridded ionization chamber and the experimental method were reported previously. Three-signals from the common cathode and two anodes were accumulated as two sets of two-dimensional data. The experimental two-dimensional data for the anode and cathode signals were transformed into the double differential cross sections. The results of the double differential cross sections, angular distributions, angle-integrated spectra in the center of mass system and total α-production cross sections are shown. (K.I.)
Neutron capture cross section of ^243Am
Jandel, M.
2009-10-01
The Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory (LANL) was used for neutron capture cross section measurement on ^243Am. The high granularity of DANCE (160 BaF2 detectors in a 4π geometry) enables the efficient detection of prompt gamma-rays following neutron capture. DANCE is located on the 20.26 m neutron flight path 14 (FP14) at the Manuel Lujan Jr. Neutron Scattering Center at the Los Alamos Neutron Science Center (LANSCE). The methods and techniques established in [1] were used for the determination of the ^243Am neutron capture cross section. The cross sections were obtained in the range of neutron energies from 0.02 eV to 400 keV. The resonance region was analyzed using SAMMY7 and resonance parameters were extracted. The results will be compared to existing evaluations and calculations. Work was performed under the auspices of the U.S. Department of Energy at Los Alamos National Laboratory by the Los Alamos National Security, LLC under Contract No. DE-AC52-06NA25396 and at Lawrence Livermore National Laboratory by the Lawrence Livermore National Security, LLC under Contract No. DE-AC52-07NA27344. [4pt] [1] M. Jandel et al., Phys. Rev. C78, 034609 (2008)
International Nuclear Information System (INIS)
Furutaka, Kazuyoshi; Nakamura, Shoji; Harada, Hideo
2004-03-01
Neutron capture cross sections of long-lived fission products (LLFP) are important quantities as fundamental data for the study of nuclear transmutation of radioactive wastes. Previously obtained thermal-neutron capture gamma-ray data were analyzed to deduce the partial neutron-capture cross sections of LLFPs including 99 Tc, 93 Zr, and 107 Pd for thermal neutrons. By comparing the decay gamma-ray data and prompt gamma-ray data for 99 Tc, the relation between the neutron-capture cross section deduced by the two different methods was studied. For the isotopes 93 Zr and 107 Pd, thermal neutron-capture gamma-ray production cross sections were deduced for the first time. The level schemes of 99 Tc, 93 Zr, and 107 Pd have also been constructed form the analyzed data and compared with previously reported levels. This work has been done under the cooperative program 'Neutron Capture Cross Sections of Long-Lived Fission products (LLFPs)' by Japan Nuclear Cycle Development Institute (JNC) and Oak Ridge National Laboratory (ORNL). (author)
International Nuclear Information System (INIS)
Maerker, R.E.
1976-01-01
The experimental and calculational details for a CSEWG integral data testing shielding experiment are presented. This particular experiment measured the secondary gamma-ray production cross sections averaged over a fast-neutron spectrum for iron, oxygen, sodium, aluminum, copper, titanium, calcium, potassium, silicon, nickel, zinc, barium, sulfur, and a type 321 stainless steel. The gamma-ray production cross sections were binned into 0.5-MeV wide gamma-ray energy intervals. 29 tables, 1 figure
Total neutron cross section for 181Ta
Directory of Open Access Journals (Sweden)
Schilling K.-D.
2010-10-01
Full Text Available The neutron time of flight facility nELBE, produces fast neutrons in the energy range from 0.1 MeV to 10 MeV by impinging a pulsed relativistic electron beam on a liquid lead circuit [1]. The short beam pulses (∼10 ps and a small radiator volume give an energy resolution better than 1% at 1 MeV using a short flight path of about 6 m, for neutron TOF measurements. The present neutron source provides 2 ⋅ 104 n/cm2s at the target position using an electron charge of 77 pC and 100 kHz pulse repetition rate. This neutron intensity enables to measure neutron total cross section with a 2%–5% statistical uncertainty within a few days. In February 2008, neutron radiator, plastic detector [2] and data acquisition system were tested by measurements of the neutron total cross section for 181Ta and 27Al. Measurement of 181Ta was chosen because lack of high quality data in an anergy region below 700 keV. The total neutron cross – section for 27Al was measured as a control target, since there exists data for 27Al with high resolution and low statistical error [3].
Measurement of actinide neutron cross sections
International Nuclear Information System (INIS)
Firestone, Richard B.; Nitsche, Heino; Leung, Ka-Ngo; Perry, DaleL.; English, Gerald
2003-01-01
The maintenance of strong scientific expertise is critical to the U.S. nuclear attribution community. It is particularly important to train students in actinide chemistry and physics. Neutron cross-section data are vital components to strategies for detecting explosives and fissile materials, and these measurements require expertise in chemical separations, actinide target preparation, nuclear spectroscopy, and analytical chemistry. At the University of California, Berkeley and the Lawrence Berkeley National Laboratory we have trained students in actinide chemistry for many years. LBNL is a leader in nuclear data and has published the Table of Isotopes for over 60 years. Recently, LBNL led an international collaboration to measure thermal neutron capture radiative cross sections and prepared the Evaluated Gamma-ray Activation File (EGAF) in collaboration with the IAEA. This file of 35, 000 prompt and delayed gamma ray cross-sections for all elements from Z=1-92 is essential for the neutron interrogation of nuclear materials. LBNL has also developed new, high flux neutron generators and recently opened a 1010 n/s D+D neutron generator experimental facility
Gamma-ray production cross sections for 0.9 to 20 MeV neutron interactions with 10B
International Nuclear Information System (INIS)
Bywater, R.L. Jr.
1986-09-01
Gamma-ray spectral data previously obtained at the 20-meter station of the Oak Ridge Electron Linear Accelerator flight-path 8 were studied to determine cross sections for 0.9- to 20-MeV neutron interactions with 10 B. Data reduction techniques, including those for determination of incident neutron fluences as well as those to compensate for Doppler-broadened gamma-ray-detection responses, are given in some detail in this report. 9 refs., 4 figs., 2 tabs
Neutron-induced fission cross sections
International Nuclear Information System (INIS)
Weigmann, H.
1991-01-01
In the history of fission research, neutron-induced fission has always played the most important role. The practical importance of neutron-induced fission rests upon the fact that additional neutrons are produced in the fission process, and thus a chain reaction becomes possible. The practical applications of neutron-induced fission will not be discussed in this chapter, but only the physical properties of one of its characteristics, namely (n,f) cross sections. The most important early summaries on the subject are the monograph edited by Michaudon which also deals with the practical applications, the earlier review article on fission by Michaudon, and the review by Bjornholm and Lynn, in which neutron-induced fission receives major attention. This chapter will attempt to go an intermediate way between the very detailed theoretical treatment in the latter review and the cited monograph which emphasizes the applied aspects and the techniques of fission cross-section measurements. The more recent investigations in the field will be included. Section II will survey the properties of cross sections for neutron-induced fission and also address some special aspects of the experimental methods applied in their measurement. Section Ill will deal with the formal theory of neutron-induced nuclear reactions for the resolved resonance region and the region of statistical nuclear reactions. In Section IV, the fission width, or fission transmission coefficient, will be discussed in detail. Section V will deal with the broader structures due to incompletely damped vibrational resonances, and in particular will address the special case of thorium and neighboring isotopes. Finally, Section VI will briefly discuss parity violation effects in neutron-induced fission. 74 refs., 14 figs., 3 tabs
Neutron capture cross sections of Kr
Directory of Open Access Journals (Sweden)
Fiebiger Stefan
2017-01-01
Full Text Available Neutron capture and β− -decay are competing branches of the s-process nucleosynthesis path at 85Kr [1], which makes it an important branching point. The knowledge of its neutron capture cross section is therefore essential to constrain stellar models of nucleosynthesis. Despite its importance for different fields, no direct measurement of the cross section of 85Kr in the keV-regime has been performed. The currently reported uncertainties are still in the order of 50% [2, 3]. Neutron capture cross section measurements on a 4% enriched 85Kr gas enclosed in a stainless steel cylinder were performed at Los Alamos National Laboratory (LANL using the Detector for Advanced Neutron Capture Experiments (DANCE. 85Kr is radioactive isotope with a half life of 10.8 years. As this was a low-enrichment sample, the main contaminants, the stable krypton isotopes 83Kr and 86Kr, were also investigated. The material was highly enriched and contained in pressurized stainless steel spheres.
Measurements of neutron spallation cross section. 2
Energy Technology Data Exchange (ETDEWEB)
Kim, E.; Nakamura, T. [Tohoku Univ., Sendai (Japan). Cyclotron and Radioisotope Center; Imamura, M.; Nakao, N.; Shibata, S.; Uwamino, Y.; Nakanishi, N.; Tanaka, Su.
1997-03-01
Neutron spallation cross section of {sup 59}Co(n,xn){sup 60-x}Co, {sup nat}Cu(n,sp){sup 56}Mn, {sup nat}Cu(n,sp){sup 58}Co, {sup nat}Cu(n,xn){sup 60}Cu, {sup nat}Cu(n,xn){sup 61}Cu and {sup nat}Cu(n,sp){sup 65}Ni was measured in the quasi-monoenergetic p-Li neutron fields in the energy range above 40 MeV which have been established at three AVF cyclotron facilities of (1) INS of Univ. of Tokyo, (2) TIARA of JAERI and (3) RIKEN. Our experimental data were compared with the ENDF/B-VI high energy file data by Fukahori and the calculated cross section data by Odano. (author)
Accurate measurements of neutron activation cross sections
International Nuclear Information System (INIS)
Semkova, V.
1999-01-01
The applications of some recent achievements of neutron activation method on high intensity neutron sources are considered from the view point of associated errors of cross sections data for neutron induced reaction. The important corrections in -y-spectrometry insuring precise determination of the induced radioactivity, methods for accurate determination of the energy and flux density of neutrons, produced by different sources, and investigations of deuterium beam composition are considered as factors determining the precision of the experimental data. The influence of the ion beam composition on the mean energy of neutrons has been investigated by measurement of the energy of neutrons induced by different magnetically analysed deuterium ion groups. Zr/Nb method for experimental determination of the neutron energy in the 13-15 MeV energy range allows to measure energy of neutrons from D-T reaction with uncertainty of 50 keV. Flux density spectra from D(d,n) E d = 9.53 MeV and Be(d,n) E d = 9.72 MeV are measured by PHRS and foil activation method. Future applications of the activation method on NG-12 are discussed. (author)
Energy Technology Data Exchange (ETDEWEB)
Zhou Hongyu; Yan Yiming; Tang lin; Wen Chenlin; Zhang Shenji; Hua Ming; Han Chongzhan; Ding Xiaoji; Lan Liqiao; Fan Guoying; Yan Hua; Wang Xingfu; Wang Qi; Sun Suxu; Rong Yaning; Liu Shuzhen (Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing (CN))
1989-05-01
The cross sections of discrete gamma-ray produced by interactions of 14.9 MeV neutrons with carbon and niobium were investigated. A pulsed {ital T}({ital d},{ital n}){sup 4} He neutron source was used in the measurement. Neutron flux incident upon the sample was determined with the associated particle method. Technique of time-of-flight was used for reducing the background. A new method to calculate neutron flux attenuation in large cylindrical sample was proposed. The split of 4.439 MeV gamma-ray line from {sup 12}C({ital n},{ital n}{prime}{gamma}){sup 12}C reactions was confirmed. 79 discrete gamma-ray lines and their production cross sections for the interactions of 14.9 MeV neutrons with niobium were obtained for the first time.
Neutron scattering cross sections of uranium-238
International Nuclear Information System (INIS)
Beghian, L.E.; Kegel, G.H.R.; Marcella, T.V.; Barnes, B.K.; Couchell, G.P.; Egan, J.J.; Mittler, A.; Pullen, D.J.; Schier, W.A.
1979-01-01
The University of Lowell high-resolution time-of-flight spectrometer was used to measure angular distributions and 90-deg excitation functions for neutrons scattered from 238 U in the energy range from 0.9 to 3.1 MeV. This study was limited to the elastic and the first two inelastic groups, corresponding to states of 238 U at 45 keV (2 + ) and 148 keV (4 + ). Angular distributions were measured at primary neutron energies of 1.1, 1.9, 2.5, and 3.1 MeV for the same three neutron groups. Whereas the elastic data are in fair agreement with the evaluation in the ENDF/B-IV file, there is substantial disagreement between the inelastic measurements and the evaluated cross sections. 12 figures
International Nuclear Information System (INIS)
Maerker, R.E.
1976-01-01
The experimental and calculational details for a CSEWG integral data testing shielding experiment are presented. This particular experiment measured the secondary gamma-ray production cross sections arising from thermal-neutron capture in iron, nitrogen, sodium, aluminum, copper, titanium, calcium, potassium, chlorine, silicon, ickel, zinc, barium, sulfur and a type 321 stainless steel. 1 figure, 30 tables
Mechanized evaluation of neutron cross-sections
International Nuclear Information System (INIS)
Horsley, A.; Parker, J.B.
1967-01-01
The evaluation work to provide accurate and consistent neutron cross-section data for multigroup neutronics calculations is not fully exploiting the available theoretical and experimental results; this has been so particularly since the introduction of on-line data handling techniques enabled experimenters to turn out vast quantities of numbers. This situation can be radically improved only by mechanizing the evaluation processes. Systems such as the SC1SRS tape will not only largely overcome the task of collecting data but will provide speedy access to it; by using computers and graph-plotting machines to tabulate and display this data, the labour of evaluation can be very greatly reduced. With some types of cross-section there is hope that by using modern curve-fitting techniques the actual evaluation and statistical accounting of the data can be performed automatically. Some areas where automatic evaluation would seem likely to succeed are specified and a discussion of the mathematical difficulties incurred, such as the elimination of anomalous data, is given. Particularly promising is the use of splines in the mechanized evaluation of data. Splines are the mathematical analogues of the draughtsman's spline used in drawing smooth curves. Their principal properties are the excellent approximations they give to the derivatives of a function; in contrast to conventional polynomial fitting, this feature ensures good interpolation and, when required, stable extrapolation. Various methods of using splines in data graduation and the problem of marrying these methods to standard statistical procedures are examined. The results of work done at AWRE with cubic splines on the mechanized evaluation of neutron scattering total cross-section and angular distribution data are presented. (author)
ISSUES IN NEUTRON CROSS SECTION COVARIANCES
Energy Technology Data Exchange (ETDEWEB)
Mattoon, C.M.; Oblozinsky,P.
2010-04-30
We review neutron cross section covariances in both the resonance and fast neutron regions with the goal to identify existing issues in evaluation methods and their impact on covariances. We also outline ideas for suitable covariance quality assurance procedures.We show that the topic of covariance data remains controversial, the evaluation methodologies are not fully established and covariances produced by different approaches have unacceptable spread. The main controversy is in very low uncertainties generated by rigorous evaluation methods and much larger uncertainties based on simple estimates from experimental data. Since the evaluators tend to trust the former, while the users tend to trust the latter, this controversy has considerable practical implications. Dedicated effort is needed to arrive at covariance evaluation methods that would resolve this issue and produce results accepted internationally both by evaluators and users.
JENDL gas-production cross section file
International Nuclear Information System (INIS)
Nakagawa, Tsuneo; Narita, Tsutomu
1992-05-01
The JENDL gas-production cross section file was compiled by taking cross-section data from JENDL-3 and by using the ENDF-5 format. The data were given to 23 nuclei or elements in light nuclei and structural materials. Graphs of the cross sections and brief description on their evaluation methods are given in this report. (author)
International Nuclear Information System (INIS)
Dickens, J.K.; Todd, J.H.; Larson, D.C.
1990-09-01
Inelastic and nonelastic neutron interactions with 56 Fe have been studied for incident neutron energies between 0.8 and 41 MeV. An iron sample isotopically enriched in the mass 56 isotope was used. Gamma rays representing 70 transitions among levels in residual nuclei were identified, and production cross sections were deduced. The reactions studied were 56 Fe(n,n') 56 Fe, 56 Fe(n,p) 56 Mn, 56 Fe(n,2n) 55 Fe, 56 Fe(n,d + n,np) 55 Mn, 56 Fe(n,t + n,nd + n,2np) 54 Mn, 56 Fe(n,α) 53 Cr, 56 Fe(n,nα) 52 Cr, and 56 Fe(n,3n) 54 Fe. Values obtained for production cross sections as functions of incident neutron energy are presented in tabular form. 38 refs., 7 figs., 12 tabs
Neutron cross section measurements at ORELA
International Nuclear Information System (INIS)
Dabbs, J.W.T.
1979-01-01
ORELA (Oak Ridge Electron Linear Accelerator) has been for the last decade the most powerful and useful pulsed neutron time-of-flight facility in the world, particularly in the broad midrange of neutron energies (10 eV to 1 MeV). This position will be enhanced with the addition of a pulse narrowing prebuncher, recently installed and now under test. Neutron capture, fission, scattering, and total cross sections are measured by members of the Physics and Engineering Physics Divisions of ORNL, and by numerous guests and visitors. Several fundamental and applied measurements are described, with some emphasis on instrumentation used. The facility comprises the accelerator and its target(s), 10 evacuated neutron flight paths having 18 measurement stations at flight path distances 8.9 to 200 meters, and a complex 4-computer data acquisition system capable of handling some 17,000 32-bit events/s from a total of 12 data input ports. The system provides a total of 2.08 x 10 6 words of data storage on 3 fast disk units. In addition, a dedicated PDP-10 timesharing system with a 250-megabyte disk system and 4 PDP-15 graphic display satellites permits on-site data reduction and analysis. More than 10 man-years of application software development supports the system, which is used directly by individual experiments. 12 figures, 1 table
[Fast neutron cross section measurements]: Progress report
International Nuclear Information System (INIS)
1988-01-01
As projected in our previous proposal, the past year on the cross section project at the University of Michigan has been one primarily of construction and assembly of our 14 MeV pulsed Neutron Facility. All the components of the system have now been either purchased or fabricated in our shop facilities and have been assembled in their final configuration. We are now in the process of testing the rf components that have been designed to deliver voltage to both the pulser and buncher stages. We expect that the system will be operational by the end of the current contract year. We have also accomplished the design and construction of several other major pieces of equipment that are needed to begin fast neutron time-of-flight measurements. These include the primary proton recoil detector, and a californium fission chamber needed in the efficiency calibration of the primary detector. We have also added considerable concrete shielding designed to lower the neutron background in the experimental area. 10 figs., 5 tabs
Energy Technology Data Exchange (ETDEWEB)
Itashiki, Yutaro; Imahayashi, Youichi; Shigyo, Nobuhiro; Uozumi, Yusuke [Kyushu University, Fukuoka (Japan); Satoh, Daiki [Japan Atomic Energy Agency, Ibaraki (Japan); Kajimoto, Tsuyoshi [Hiroshima University, Hiroshima (Japan); Sanami, Toshiya [High Energy Accelerator Research Organization, Ibaraki (Japan); Koba, Yusuke; Matufuji, Naruhiro [Institutes for Quantum and Radiological Science and Technology, Chiba (Japan)
2016-12-15
Carbon ion therapy has achieved satisfactory results. However, patients have a risk to get a secondary cancer. In order to estimate the risk, it is essential to understand particle transportation and nuclear reactions in the patient's body. The particle transport Monte Carlo simulation code is a useful tool to understand them. Since the code validation for heavy ion incident reactions is not enough, the experimental data of the elementary reaction processes are needed. We measured neutron production double-differential cross-sections (DDXs) on a carbon bombarded with 430 MeV/nucleon carbon beam at PH2 beam line of HIMAC facility in NIRS. Neutrons produced in the target were measured with NE213 liquid organic scintillators located at six angles of 15, 30, 45, 60, 75, and 90°. Neutron production double-differential cross-sections for carbon bombarded with 430 MeV/nucleon carbon ions were measured by the time-of-flight method with NE213 liquid organic scintillators at six angles of 15, 30, 45, 60, 75, and 90°. The cross sections were obtained from 1 MeV to several hundred MeV. The experimental data were compared with calculated results obtained by Monte Carlo simulation codes PHITS, Geant4, and FLUKA. PHITS was able to reproduce neutron production for elementary processes of carbon-carbon reaction precisely the best of three codes.
Measurements of neutron cross sections of radioactive waste nuclides
Energy Technology Data Exchange (ETDEWEB)
Katoh, Toshio [Gifu College of Medical Technology, Seki, Gifu (Japan); Harada, Hideo; Nakamura, Shoji; Tanase, Masakazu; Hatsukawa, Yuichi
1998-01-01
Accurate nuclear reaction cross sections of radioactive fission products and transuranic elements are required for research on nuclear transmutation methods in nuclear waste management. Important fission products in the nuclear waste management are {sup 137}Cs, {sup 135}Cs, {sup 90}Sr, {sup 99}Tc and {sup 129}I because of their large fission yields and long half-lives. The present authors have measured the neutron capture cross sections and resonance integrals of {sup 137}Cs, {sup 90}Sr and {sup 99}Tc. The purpose of this study is to measure the neutron capture cross sections and resonance integrals of nuclides, {sup 129}I and {sup 135}Cs accurately. Preliminary experiments were performed by using Rikkyo University Reactor and JRR-3 reactor at Japan Atomic Energy Research Institute (JAERI). Then, it was decided to measure the cross section and resonance integral of {sup 135}Cs by using the JRR-3 Reactor because this measurement required a high flux reactor. On the other hand, those of {sup 129}I were measured at the Rikkyo Reactor because the product nuclides, {sup 130}I and {sup 130m}I, have short half-lives and this reactor is suitable for the study of short lived nuclide. In this report, the measurements of the cross section and resonance integral of {sup 135}Cs are described. To obtain reliable values of the cross section and resonance integral of {sup 135}Cs(n, {gamma}){sup 136}Cs reaction, a quadrupole mass spectrometer was used for the mass analysis of nuclide in the sample. A progress report on the cross section of {sup 134}Cs, a neighbour of {sup 135}Cs, is included in this report. A report on {sup 129}I will be presented in the Report on the Joint-Use of Rikkyo University Reactor. (author)
Energy Technology Data Exchange (ETDEWEB)
Youinou, Gilles Jean-Michel [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2015-10-01
Neutron cross-sections characterize the way neutrons interact with matter. They are essential to most nuclear engineering projects and, even though theoretical progress has been made as far as the predictability of neutron cross-section models, measurements are still indispensable to meet tight design requirements for reduced uncertainties. Within the field of fission reactor technology, one can identify the following specializations that rely on the availability of accurate neutron cross-sections: (1) fission reactor design, (2) nuclear fuel cycles, (3) nuclear safety, (4) nuclear safeguards, (5) reactor monitoring and neutron fluence determination and (6) waste disposal and transmutation. In particular, the assessment of advanced fuel cycles requires an extensive knowledge of transuranics cross sections. Plutonium isotopes, but also americium, curium and up to californium isotope data are required with a small uncertainty in order to optimize significant features of the fuel cycle that have an impact on feasibility studies (e.g. neutron doses at fuel fabrication, decay heat in a repository, etc.). Different techniques are available to determine neutron cross sections experimentally, with the common denominator that a source of neutrons is necessary. It can either come from an accelerator that produces neutrons as a result of interactions between charged particles and a target, or it can come from a nuclear reactor. When the measurements are performed with an accelerator, they are referred to as differential since the analysis of the data provides the cross-sections for different discrete energies, i.e. σ(E_{i}), and for the diffusion cross sections for different discrete angles. Another approach is to irradiate a very pure sample in a test reactor such as the Advanced Test Reactor (ATR) at INL and, after a given time, determine the amount of the different transmutation products. The precise characterization of the nuclide densities before and after
International Nuclear Information System (INIS)
Benck, S.; Slypen, I.; Meulders, J.P.; Corcalciuc, V.
2001-01-01
Experimental double-differential cross sections (d 2 σ/dΩdE) for fast neutron-induced proton, deuteron, triton, and alpha-particle production on aluminum are reported, at several incident neutron energies between 25 and 65 MeV, for outgoing particle energies above the experimental energy thresholds. Angular distributions were measured at laboratory angles between 20 deg. and 160 deg. . Reliable extrapolated spectra are derived for very forward (2.5 deg. and 10 deg. ) and very backward angles (170 deg. and 177.5 deg. ). Based on these experimental data, energy-differential (dσ/dE), angle-differential (dσ/dΩ), and total production cross sections (σ T ) are reported for each outgoing particle
International Nuclear Information System (INIS)
Zhou Hongyu; Tang Lin; Yan Yiming
1986-11-01
Discrete γ-ray spectra and production cross sections for the interactions of 14.9 MeV neutrons with C, Al, V, Fe and Nb targets have been measured at 90 deg. using a 110.7cm 3 Ge(Li) detector. A single γ-ray peak was measured for C. For Al 34 γ lines, for Fe 41 γ lines, for V 61 γ lines and for Nb 79 γ lines were measured
New neutron cross sections for fusion materials studies
International Nuclear Information System (INIS)
Greenwood, L.R.; Smither, R.K.
1985-01-01
Neutron cross sections are being developed for a variety of fusion-related applications including neutron dosimetry, fusion plasma diagnostics, the activation of very long-lived isotopes, and high-energy accelerator neutron sources
International Nuclear Information System (INIS)
Iwamoto, Yousuke; Iga, Kiminori; Kitsuki, Hirohiko
2000-01-01
Double-differential neutron-production yields for 870-MeV π + , π - and 2.1-GeV π + incident on iron and lead targets were measured with NE213 liquid scintillators by time-of-flight technique. The two-gate integration method was used for the pulse shape discrimination between neutrons and gamma-rays. Neutron detection efficiencies were derived from the calculation results of SCINFUL and CECIL codes. The experimental results were compared with the calculation including the neutron transport in the actual thickness target by the contribution use of both NMTC/JAERI97 and MCNPX. (author)
International Nuclear Information System (INIS)
Tang Lin; Yan Yiming; Zhou Hongyu; Wen Shenlin; Wang Qi; Sun Shuxu; Ding Xiaoji; Wang Wanhong
1987-04-01
The (n,xr) reactions have been studied for incident neutron energy 14.9 Mev and for the samples C, Al, V, Fe, Co and Nb. The pulsed beam Time-of-Flight technique was adopted to discriminate neutrons and de-excitation r-rays and to improve the background conditions of the experiment. 90 deg. differential gamma production cross sections as the results of experiments are presented. Due to very low background many new r-rays peaks have been obtained. (author). 14 refs, 12 figs, 1 tab
Fission-neutron displacement cross sections in metals
International Nuclear Information System (INIS)
Takamura, Saburo; Aruga, Takeo; Nakata, Kiyotomo
1985-01-01
The sensitivity damage rates for 22 metals were measured after fission-spectrum neutron irradiation at low temperature and the experimental damage rates were compared with the theoretical calculation. The relation between the theoretical displacement cross section and the atomic weight of metals can be written by two curves; one is for fcc and hcp metals, and another is for bcc metals. On the other hand, the experimental displacement cross section versus atomic weight is shown approximately by a curve for both fcc and bcc metals, and the cross section for hcp metals deviates from the curve. The defect production efficiency is 0.3-0.4 for fcc metals and 0.6-0.8 for bcc metals. (orig.)
Tables of RCN-2 fission-product cross section evaluation
International Nuclear Information System (INIS)
Gruppelaar, H.
1979-05-01
This report (continuation of ECN-13 and ECN-33) describes the third part of the RCN-2 evaluation of neutron cross sections for fission product nuclides in KEDAK format. It contains evaluated data for nine nuclides, i.e. 142 Nd, 143 Nd, 144 Nd, 145 Nd, 146 Nd, 147 Nd, 148 Nd, 150 Nd and 147 Pm. Most emphasis has been given to the evaluation of the radiative capture cross section, in order to provide a data base for adjustment calculations using results of integral measurements. Short evaluation reports are given for this cross section. The evaluated capture cross sections are compared with recent experimental differential and integral data. Graphs are given of the capture cross sections at neutron energies above 1 keV, in which also adjusted point cross sections, based upon integral STEK and CFRMF data have been plotted. Moreover, the results are compared with those of the well-known ENDF/B-IV evaluation for fission product nucleides. Finally, evaluation summaries are given, which include tables of other important neutron cross sections, such as the total, elastic scattering and inelastic scattering cross sections
Measurement of gamma-ray production cross sections in neutron-induced reactions for Al and Pb
International Nuclear Information System (INIS)
Pavlik, A.; Vonach, H.; Hitzenberger, H.
1995-01-01
The prompt gamma-radiation from the interaction of fast neutrons with aluminum and lead was measured using the white neutron beam of the WNR facility at the Los Alamos National Laboratory. The samples (Al and isotopically enriched 207 Pb and 208 Pb) were positioned at about 20 m or 41 m distance from the neutron production target. The spectra of the emitted gamma-rays were measured with a high-resolution HPGe detector. The incident neutron energy was determined by the time-of-flight method and the neutron fluence was measured with a U fission chamber. From the aluminum gamma-ray spectra excitation functions for prominent gamma-transitions in various residual nuclei (in the range from O to Al) were derived for neutron energies from 3 MeV to 400 MeV. For lead (n,xnγ) reactions were studied for neutron energies up to 200 MeV by analyzing prominent gamma-transitions in the residual nuclei 200,202,204,206,207,208 Pb. The experimental results were compared with nuclear model calculations using the code GNASH. A good overall agreement was obtained without special parameter adjustments
Status of neutron dosimetry cross sections
International Nuclear Information System (INIS)
Griffin, P.J.; Kelly, J.G.
1992-01-01
Several new cross section libraries, such as ENDF/B-VI(release 2), IRDF-90,JEF-2.2, and JENDL-3 Dosimetry, have recently been made available to the dosimetry community. the Sandia National Laboratories (SNL) Radiation Metrology Laboratory (RML) has worked with these libraries since pre-release versions were available. this paper summarizes the results of the intercomparison and testing of dosimetry cross sections. As a result of this analysis, a compendium of the best dosimetry cross sections was assembled from the available libraries for use within the SNL RML. this library, referred to as the SNLRML Library, contains 66 general dosimetry sensors and 3 special dosimeters unique to the RML sensor inventory. The SNLRML cross sections have been put into a format compatible with commonly used spectrum determination codes
238U subthreshold neutron induced fission cross section
International Nuclear Information System (INIS)
Difilippo, F.C.; Perez, R.B.; De Saussure, G.; Olsen, D.K.; Ingle, R.W.
1976-01-01
High resolution measurements of the 238 U neutron induced fission cross section are reported for neutron energies between 600 eV and 2 MeV. The average subthreshold fission cross section between 10 and 100 keV was found to be 44 +- 6 μb
Energy Technology Data Exchange (ETDEWEB)
Billaud, P; Clair, C; Gaudin, M; Genin, R; Joly, R; Leroy, J L; Michaudon, A; Ouvry, J; Signarbieux, C; Vendryes, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1958-07-01
a) Measurements of neutron induced fission cross-sections in the low energy region. The variation of the fission cross sections of several fissile isotopes has been measured and analysed, for neutron energies below 0,025 eV. The monochromator was a crystal spectrometer used in conjunction with a mechanical velocity selector removing higher order Bragg reflections. The fissile material was laid down on the plates of a fission chamber by painting technic. An ionization chamber, having its plates coated with thin {sup 10}B layers, was used as the neutron flux monitor. b) Measurement of the fission cross section of {sup 235}U. We intend to measure the variation of the neutron induced fission cross section of {sup 235}U over the neutron energy range from 1 keV by the time of flight method. The neutron source is the uranium target of a pulsed 28 MeV electron linear accelerator. The detector is a large fission chamber, with parallel plates, containing about 10 g of {sup 235}U (20 deposits of 25 cm diameter). The relative fission data were corrected for the neutron spectrum measured with a set of BF{sub 3} proportional counters. c) Mean number {nu} of neutrons emitted in neutron induced fission. We measured the value of {nu} for several fissile isotopes in the case of fission induced by 14 MeV neutrons. The 14 MeV neutrons were produced by D (t, n) {alpha} reaction by means of a 300 kV Cockcroft Walton generator. (author)Fren. [French] a) Mesures de sectionficaces de fission a basse energie. Nous avons mesure et analyse la variation de la section efficace de fission de divers isotopes fissiles pour des neutrons d'energie inferieure a 0,025 eV. Le monochromateur est constitue par un spectrometre a cristal auquel est associe un selecteur mecanique destine a eliminer les diffractions de Bragg d'ordre superieur au premier. Le materiau fissile est contenu dans une chambre a fission sous forme de depots realises par peinture; une chambre d'ionisation a depots minces de B{sub 10
Secondary standard neutron detector for measuring total reaction cross sections
International Nuclear Information System (INIS)
Sekharan, K.K.; Laumer, H.; Gabbard, F.
1975-01-01
A neutron detector has been constructed and calibrated for the accurate measurement of total neutron-production cross sections. The detector consists of a polyethylene sphere of 24'' diameter in which 8- 10 BF 3 counters have been installed radially. The relative efficiency of this detector has been determined for average neutron energies, from 30 keV to 1.5 MeV by counting neutrons from 7 Li(p,n) 7 Be. By adjusting the radial positions of the BF 3 counters in the polyethylene sphere the efficiency for neutron detection was made nearly constant for this energy range. Measurement of absolute efficiency for the same neutron energy range has been done by counting the neutrons from 51 V(p,n) 51 Cr and 57 Fe(p,n) 57 Co reactions and determining the absolute number of residual nuclei produced during the measurement of neutron yield. Details of absolute efficiency measurements and the use of the detector for measurement of total neutron yields from neutron producing reactions such as 23 Na(p,n) 23 Mg are given
International Nuclear Information System (INIS)
Iwamoto, Yosuke; Satoh, Daiki; Hagiwara, Masayuki; Yashima, Hiroshi; Nakane, Yoshihiro; Tamii, Atsushi; Iwase, Hiroshi; Endo, Akira; Nakashima, Hiroshi; Sakamoto, Yukio; Hatanaka, Kichiji; Niita, Koji
2010-01-01
The neutron production cross-sections of carbon, iron, and gold targets with 140 MeV protons at 180 o were measured at the RCNP cyclotron facility. The time-of-flight technique was used to obtain the neutron energy spectra in the energy range above 1 MeV. The carbon and iron target results were compared with the experimental data from 113 MeV (p,xn) reactions at 150 o reported by Meier et al. Our data agreed well with them in spite of different incident energies and angles. Calculations were then performed using different intra-nuclear cascade models (Bertini, ISOBAR, and JQMD) implemented with PHITS code. The results calculated using the ISOBAR and JQMD models roughly agreed with the experimental iron and gold target data, but the Bertini could not reproduce the high-energy neutrons above 10 MeV.
International Nuclear Information System (INIS)
Pashchenko, A.B.
1996-09-01
The present report contains the Summary of the Third and Final IAEA Research Co-ordination Meeting (RCM) on ''Improvement of Measurements, Theoretical Computations and Evaluations of Neutron Induced Helium Production Cross Sections'' which was hosted by the Tohoku University and held in Sendai, Japan, from 25 to 29 September 1995. This RCM was organized by the IAEA Nuclear Data Section (NDS), with the co-operation and assistance of local organizers from Tohoku University. Summarized are the proceedings and results of the meeting. The List of Participants and meeting Agenda are included. (author)
International Nuclear Information System (INIS)
Brenner, D.J.; Prael, R.E.
1989-01-01
Calculated values are given for double-differential (energy/angle) cross sections for the nonelastic production of hydrogen and helium isotopes and heavier-mass recoils, after the interaction of 15- to 60-MeV neutrons with carbon and oxygen. The data are calculated with an intranuclear cascade code, including alpha clustering and particle pickup, followed by a Fermi-breakup mechanism, incorporating decay via intermediate particle-unstable states. The predictions have been extensively tested against available experimental data in this energy/mass range. copyright 1989 Academic Press, Inc
Neutron Cross Section Libraries for Cryogenic Aromatic Moderator Materials
International Nuclear Information System (INIS)
Cantargi, Florencia; Granada, J.R.; Sbaffoni, Maria Monica
2008-01-01
The dynamics of a set of aromatic hydrocarbons, such as benzene, toluene, mesitylene and a 3:2 mixture (by volume) of mesitylene and toluene, all of them in solid phase, was studied as potential moderator materials for cold neutron sources. Cross section libraries were generated for hydrogen bounded in those materials, at several temperatures in ACE format, and they were used in MCNP calculations to analyze their neutron production compared with traditional materials like solid methane and liquid hydrogen. In particular, cross section libraries were generated at 20 K, which is the operating temperature of the majority of the existing cold neutron sources. Although solid methane is the best moderator in terms of cold neutron production, it has very poor radiation resistance, causing spontaneous burping even at fairly low doses. Such effect is considerably reduced in the aromatic hydrocarbons. On the other hand, all of them show a similar and significant neutron production, with the exception of benzene. Even though those aromatic materials are very easy to handle, the solid phases that produce an enhanced flux of cold neutrons correspond to amorphous structures rich in low-energy excitations, and they can be created through lengthy cooling processes requiring in many cases additional annealing stages. The 3:2 mesitylene-toluene mixture, that forms in a simple and direct manner the appropriate disordered structure, constitutes an excellent cryogenic moderator material, as it is able to produce an intense flux of cold neutrons while presenting high resistance to radiation, thus conforming a new and advantageous alternative to traditional moderator materials. (authors)
Neutron capture cross section standards for BNL 325, Fourth Edition
International Nuclear Information System (INIS)
Holden, N.E.
1981-01-01
This report evaluates the experimental data and recommends values for the thermal neutron cross sections and resonance integrals for the neutron capture reactions: 55 Mn(n,γ), 59 Co(n,γ) and 197 Au(n,γ). The failure of lithium and boron as standards due to the natural variation of the absorption cross sections of these elements is discussed. The Westcott convention, which describes the neutron spectrum as a thermal Maxwellian distribution with an epithermal component, is also discussed
Average cross sections for the 252Cf neutron spectrum
International Nuclear Information System (INIS)
Dezso, Z.; Csikai, J.
1977-01-01
A number of average cross sections have been measured for 252 Cf neutrons in (n, γ), (n,p), (n,2n), (n,α) reactions by the activation method and for fission by fission chamber. Cross sections have been determined for 19 elements and 45 reactions. The (n,γ) cross section values lie in the interval from 0.3 to 200 mb. The data as a function of target neutron number increases up to about N=60 with minimum near to dosed shells. The values lie between 0.3 mb and 113 mb. These cross sections decrease significantly with increasing the threshold energy. The values are below 20 mb. The data do not exceed 10 mb. Average (n,p) cross sections as a function of the threshold energy and average fission cross sections as a function of Zsup(4/3)/A are shown. The results obtained are summarized in tables
Cross sections for charm production by neutrinos
Energy Technology Data Exchange (ETDEWEB)
Ushida, N [Aichi Univ. of Education, Kariya (Japan). Dept. of Physics; Kondo, T [Fermi National Accelerator Lab., Batavia, IL (USA); Fujioka, G; Fukushima, J; Takahashi, Y; Tatsumi, S; Yokoyama, C [Kobe Univ. (Japan). Dept. of Physics; Homma, Y; Tsuzuki, Y [Kobe Univ. (Japan). Coll. of Liberal Arts; Bahk, S
1983-02-03
The production of charmed particles has been measured using a hybrid emulsion spectrometer in the Fermilab wide-band neutrino beam. The relative cross section for charged current charmed particle production is sigma(v -> ..mu../sup -/c)/sigma(v -> ..mu../sup -/) = 6.5 +- 1.9/1.8%, and the energy dependence of the cross section is presented. One event with charm pair production was observed. A limit of sigma(v -> ..mu..canti c)/sigma(v -> ..mu..c) < 6% (90% CL) is found for the ratio of charged current pair and single charm production.
Top quark production cross-section measurements
Chen, Ye; The ATLAS collaboration
2017-01-01
Measurements of the inclusive and differential cross-sections for top-quark pair and single top production cross sections in proton-proton collisions with the ATLAS detector at the Large Hadron Collider are presented at center-of-mass energies of 8 TeV and 13 TeV. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. These measurements, including results using boosted tops, probe our understanding of top-pair production in the TeV regime. The results are compared to Monte Carlo generators implementing LO and NLO matrix elements matched with parton showers and NLO QCD calculations. For the t-channel single top measurement, the single top-quark and anti-top-quark total production cross-sections, their ratio, as well as differential cross sections are also presented. A measurement of the production cross-section of a single top quark in association with a W boson, the second largest single-top production mode, is also presented. Finally, measurements of ...
Damage energy and displacement cross sections: survey and sensitivity. [Neutrons
Energy Technology Data Exchange (ETDEWEB)
Doran, D.G.; Parkin, D.M.; Robinson, M.T.
1976-10-01
Calculations of damage energy and displacement cross sections using the recommendations of a 1972 IAEA Specialists' Meeting are reviewed. The sensitivity of the results to assumptions about electronic energy losses in cascade development and to different choices respecting the nuclear cross sections is indicated. For many metals, relative uncertainties and sensitivities in these areas are sufficiently small that adoption of standard displacement cross sections for neutron irradiations can be recommended.
Microscopic cross-section measurements by thermal neutron activation
International Nuclear Information System (INIS)
Avila L, J.
1987-08-01
Microscopic cross sections measured by thermal neutron activation using RP-0 reactor at the Peruvian Nuclear Energy Institute. The method consists in measuring microscopic cross section ratios through activated samples, requiring being corrected in thermal and epithermal energetic range by Westcott formalism. Furthermore, the comptage ratios measured for each photopeak to its decay fraction should be normalized from interrelation between both processes above, activation microscopic cross sections are obtained
Neutron total scattering cross sections of elemental antimony
Energy Technology Data Exchange (ETDEWEB)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-11-01
Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V.
Actinide neutron-induced fission cross section measurements at LANSCE
Energy Technology Data Exchange (ETDEWEB)
Tovesson, Fredrik K [Los Alamos National Laboratory; Laptev, Alexander B [Los Alamos National Laboratory; Hill, Tony S [INL
2010-01-01
Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.
Neutron total scattering cross sections of elemental antimony
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-11-01
Neutron total cross sections are measured from 0.8 to 4.5 MeV with broad resolutions. Differential-neutron-elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at intervals of 50 to 200 keV and at scattering angles distributed between 20 and 160 degrees. Lumped-level neutron-inelastic-scattering cross sections are measured over the same angular and energy range. The exPerimental results are discussed in terms of an optical-statistical model and are compared with respective values given in ENDF/B-V
Graphs of neutron cross section data for fusion reactor development
International Nuclear Information System (INIS)
Asami, Tetsuo; Tanaka, Shigeya
1979-03-01
Graphs of neutron cross section data relevant to fusion reactor development are presented. Nuclides and reaction types in the present compilation are based on a WRENDA request list from Japan for fusion reactor development. The compilation contains various partial cross sections for 55 nuclides from 6 Li to 237 Np in the energy range up to 20 MeV. (author)
International Nuclear Information System (INIS)
Abbasi, I.A.; Subhani, M.S.; Zaidi, J.H.; Arif, M.
2006-01-01
Systematic studies on fission neutron spectrum averaged cross sections of some threshold reactions like (n, p) and (n, α) on cadmium were carried out using the activation technique in combination with radiochemical separations and high-resolution γ-ray spectroscopy. Special attention was paid to the formation of 103 Pd via the 106 Cd(n,a α) 103 Pd reaction since it is an important therapeutic radionuclide. At a fast flux neutron density of 7.5 x 10 13 cm 2 s -1 and an irradiation time of 120 h, using 100% enriched 106 Cd target 340 MBq of no-carrier-added 103 Pd per batch could be produced. The method is thus suitable for medium-scale production of this radionuclide. (orig.)
Neutron cross-section determination in geological samples (U)
International Nuclear Information System (INIS)
Harris, J.M.; McDaniel, P.J.
1982-01-01
The Prompt Gamma Neutron Activation Analysis (PGAA) technique yields elemental composition data which can be used to calculate the macroscopic cross section for any sample. The Small Sample Reactivity Measurements (SSRM) technique yields the macroscopic thermal absorption directly. Experimentally, PGAA is somewhat more difficult because of the calibration and data handling than is SSRM. However, SSRM requires a mathematical model of the reactor which means a rather complicated analysis. Once the model and calibration are completed, data analysis is routine. The SSRM technique is production oriented. 9 figures
Thermal neutron capture cross sections of tellurium isotopes
International Nuclear Information System (INIS)
Tomandl, I.; Honzatko, J.; Egidy, T. von; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.
2003-01-01
New values for thermal neutron capture cross sections of the tellurium isotopes 122 Te, 124 Te, 125 Te, 126 Te, 128 Te, and 130 Te are reported. These values are based on a combination of newly determined partial γ-ray cross sections obtained from experiments on targets contained natural Te and γ intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given
Thermal neutron capture cross sections of tellurium isotopes
International Nuclear Information System (INIS)
Tomandl, I.; Honzatko, J.; Egidy, T. von; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.
2004-01-01
New values for thermal neutron capture cross sections of the tellurium isotopes 122Te, 124Te, 125Te, 126Te, 128Te, and 130Te are reported. These values are based on a combination of newly determined partial g-ray cross sections obtained from experiments on targets contained natural Te and gamma intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given
Thermal neutron capture cross sections of tellurium isotopes
Energy Technology Data Exchange (ETDEWEB)
Tomandl, I.; Honzatko, J.; von Egidy, T.; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.
2004-03-01
New values for thermal neutron capture cross sections of the tellurium isotopes 122Te, 124Te, 125Te, 126Te, 128Te, and 130Te are reported. These values are based on a combination of newly determined partial g-ray cross sections obtained from experiments on targets contained natural Te and gamma intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given.
International Nuclear Information System (INIS)
Kitsuki, Hirohiko; Shigyo, Nobuhiro; Ishibashi, Kenji
2000-01-01
The moving source model based on the Maxwell-like energy distribution with Gaussian shape terms are employed for analyzing the neutron emission spectra from proton-induced spallation reaction. The parallelization of the double differential cross section is made for the experimental and calculated neutron data in the energy region from several-tens MeV to 3 GeV. (author)
Neutron standard cross sections in reactor physics - Need and status
International Nuclear Information System (INIS)
Carlson, A.D.
1990-01-01
The design and improvement of nuclear reactors require detailed neutronics calculations. These calculations depend on comprehensive libraries of evaluated nuclear cross sections. Most of the cross sections that form the data base for these evaluations have been measured relative to neutron cross-section standards. The use of these standards can often simplify the measurement process by eliminating the need for a direct measurement of the neutron fluence. The standards are not known perfectly, however; thus the accuracy of a cross-section measurement is limited by the uncertainty in the standard cross section relative to which it is measured. Improvements in a standard cause all cross sections measured relative to that standard to be improved. This is the reason for the emphasis on improving the neutron cross-section standards. The continual process of measurement and evaluation has led to improvements in the accuracy and range of applicability of the standards. Though these improvements have been substantial, this process must continue in order to obtain the high-quality standards needed by the user community
Thermal neutron cross section measurements for technetium-99
International Nuclear Information System (INIS)
Yates, M.A.; Schroeder, N.C.; Fowler, M.M.
1993-01-01
Technetium, because of its long half-like (213,000 years) and ability to migrate in the environment, is a primary contributor to the long-term radioactivity related risk associated with geologic nuclear waste disposal. One proposal for converting technetium to an environmentally benign element investigating transmutation with an accelerator-based system, (i.e., Accelerator Transmutation of Waste, ATW). Planning for efficient processing of technetium through the transmuter will require knowledge of the thermal neutron cross section for the 99 Tc (n,γ) 100 Tc reaction. The authors have recently remeasured this cross section. Weighed aliquots (19-205 μg) of a NIST traceable 99 Tc standard were irradiated for 30-150 sec using the pneumatic open-quotes rabbitclose quotes system of LANL's Omega West Reactor. The two gamma rays from the 15.7-sec half-life product were measured immediately after irradiation on a high-resolution Ge detector. Thermal fluxes were measured using gold foils and Cd wrapped gold foils. The observation cross section is 19 ± 1 b. This agrees well with the 1977 value but has half the uncertainty
Double-differential heavy-ion production cross sections
International Nuclear Information System (INIS)
Miller, T. M.; Townsend, L. W.
2004-01-01
Current computational tools used for space or accelerator shielding studies transport energetic heavy ions either using a one-dimensional straight-ahead approximation or by dissociating the nuclei into protons and neutrons and then performing neutron and proton transport using Monte Carlo techniques. Although the heavy secondary particles generally travel close to the beam direction, a proper treatment of the light ions produced in these reactions requires that double-differential cross sections should be utilised. Unfortunately, no fundamental nuclear model capable of serving as an event generator to provide these cross sections for all ions and energies of interest exists currently. Herein, we present a model for producing double-differential heavy-ion production cross sections that uses heavy-ion fragmentation yields produced by the NUCFRG2 fragmentation code coupled with a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions to provide energy and angular dependences of the heavy-ion production. (authors)
Re/Os cosmochronometer: measurement of neutron cross sections
International Nuclear Information System (INIS)
Mosconi, M.
2007-01-01
This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of 187 Re (t 1/2 =41.2 Gyr) into 187 Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the 187 Re/ 187 Os pair, provide the possibility to identify the radiogenic fraction of 187 Os exclusively by nuclear physics considerations. Apart from its radiogenic component, 187 Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, 187 Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of 187 Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of 187 Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of 186 Os, 187 Os and 188 Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for 186 Os, 187 Os, and 188 Os, respectively. Since, the first excited state in 187 Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, γ) experiments and by an improved measurements of the inelastic scattering cross section for
Re/Os cosmochronometer: measurement of neutron cross sections
Energy Technology Data Exchange (ETDEWEB)
Mosconi, M.
2007-12-21
This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of {sup 187}Re (t{sub 1/2}=41.2 Gyr) into {sup 187}Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the {sup 187}Re/{sup 187}Os pair, provide the possibility to identify the radiogenic fraction of {sup 187}Os exclusively by nuclear physics considerations. Apart from its radiogenic component, {sup 187}Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, {sup 187}Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of {sup 187}Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of {sup 187}Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of {sup 186}Os, {sup 187}Os and {sup 188}Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for {sup 186}Os, {sup 187}Os, and {sup 188}Os, respectively. Since, the first excited state in {sup 187}Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, {gamma
Porosity effects in the neutron total cross section of graphite
International Nuclear Information System (INIS)
Santisteban, J. R; Dawidowski, J; Petriw, S. N
2009-01-01
Graphite has been used in nuclear reactors since the birth of the nuclear industry due to its good performance as a neutron moderator material. Graphite is still an option as moderator for generation IV reactors due to its good mechanical and thermal properties at high operation temperatures. So, there has been renewed interest in a revision of the computer libraries used to describe the neutron cross section of graphite. For sub-thermal neutron energies, polycrystalline graphite shows a larger total cross section (between 4 and 8 barns) than predicted by existing theoretical models (0.2 barns). In order to investigate the origin of this discrepancy we measured the total cross section of graphite samples of three different origins, in the energy range from 0.001 eV to 10 eV. Different experimental arrangements and sample treatments were explored, to identify the effect of various experimental parameters on the total cross section measurement. The experiments showed that the increase in total cross section is due to neutrons scattered around the forward direction. We associate these small-angle scattered neutrons (SANS) to the porous structure of graphite, and formulate a very simple model to compute its contribution to the total cross section of the material. This results in an analytic expression that explicitly depends on the density and mean size of the pores, which can be easily incorporated in nuclear library codes. [es
Blokhin, A I; Manokhin, V N; Mikhajlyukova, M V; Nasyrova, S M; Skripova, M V
2001-01-01
The present paper analyses and evaluates the cross-sections of threshold reactions leading to the production of long-lived radionuclides during the irradiation, by thermonuclear spectrum neutrons, of steels containing V, Ti, Cr, Fe and Ni. On the basis of empirical systematics. a new evaluation of the (n,2n), (n,p), (n,np), (n,alpha) and (n,n alpha) excitation functions is made for all isotopes of V, Ti, Cr, Fe and Ni and for intermediate isotopes produced in the chain from irradiated isotopes up to production of the long-lived radionuclides sup 3 sup 9 Ar, sup 4 sup 2 Ar, sup 4 sup 1 Ca, sup 5 sup 3 Mn, sup 6 sup 0 Fe, sup 6 sup 0 Co, sup 5 sup 9 Ni and sup 6 sup 3 Ni. A comparison is made with the experimental and other evaluated data.
International Nuclear Information System (INIS)
Blokhin, A.I.; Buleeva, N.N.; Manokhin, V.N.; Mikhajlyukova, M.V.; Nasyrova, S.M.; Skripova, M.V.
2002-01-01
The present paper analyses and evaluates the cross-sections of threshold reactions leading to the production of long-lived radionuclides during the irradiation, by thermonuclear spectrum neutrons, of steels containing V, Ti, Cr, Fe and Ni. On the basis of empirical systematics. a new evaluation of the (n,2n), (n,p), (n,np), (n,α) and (n,nα) excitation functions is made for all isotopes of V, Ti, Cr, Fe and Ni and for intermediate isotopes produced in the chain from irradiated isotopes up to production of the long-lived radionuclides 39 Ar, 42 Ar, 41 Ca, 53 Mn, 60 Fe, 60 Co, 59 Ni and 63 Ni. A comparison is made with the experimental and other evaluated data. (author)
Measurement of 0.8 and 1.5 GeV proton induced neutron production cross sections at 0deg
International Nuclear Information System (INIS)
Shigyo, Nobuhiro; Kunieda, Satoshi; Watanabe, Takehito; Ishibashi, Kenji; Satoh, Daiki; Meigo, Shin-ichiro
2004-01-01
Neutron-production double-differential cross sections at 0deg were measured for proton-induced reactions on Fe and Pb targets at 0.8 and 1.5 GeV. The experiment was performed at the π2 beam line of the 12 GeV proton synchrotron in High Energy Accelerator Research Organization (KEK). Neutrons were measured by time-of-flight technique with two different flight path lengths, i.e. 3.5 and 5.0 m at 0.8 and 1.5 GeV, respectively. NE213 liquid organic scintillators 12.7 cm in diameter and 12.7 cm in thickness were set at 0deg as neutron detector. For the improvement of the energy resolution, the scintillator was connected with three Hamamatsu H2431 photomultipliers 5.1 cm in diameter. The neutron detection efficiencies were obtained by the SCINFUL-QMD code. The experimental data were compared with the calculation results of the intranuclear-cascade-evaporation (INC/E) and the quantum-molecular-dynamics (QMD) models. (author)
Energy Technology Data Exchange (ETDEWEB)
Ejnisman, R
1994-12-31
A study of the production of a {sup 44} Ti target was carried out aiming the determination of its thermal neutron capture cross-section. With this purpose, the cross-section of the reaction {sup 45} Sc(p,2 n) {sup 44} Ti was determined in the energies 16-, 18-, 20-22- and 45 MeV. The cross-section of the reactions (p,n) {sup 45} Ti, (p,pn) {sup 44m} Sc, (p,pn) {sup 44g} Sc and (p,p2n){sup 43} Sc were also measured. The results in the low energy region are in good agreement with a previous work by McGee et al. On the other hand, the cross-section at 45 MeV is different from McGee`s result and indicates the existence of an abnormal behavior of the excitation function at higher energies. Furthermore, a radiochemical separation method was developed in order to eliminate Sc from the {sup 44} Ti target which was irradiated with neutrons. It was possible to determine an upper limit for the cross-section of the reaction {sup 44} Ti (n, {gamma}) of 4 x 10{sup 3} b. At last, it is presented a discussion of the results obtained and their possible astrophysical implications. (author) 94 refs.
Measurement cross sections for radioisotopes production
International Nuclear Information System (INIS)
Garrido, E.
2011-01-01
New radioactive isotopes for nuclear medicine can be produced using particle accelerators. This is one goal of Arronax, a high energy - 70 MeV - high intensity - 2*350 μA - cyclotron set up in Nantes. A priority list was established containing β - - 47 Sc, 67 Cu - β + - 44 Sc, 64 Cu, 82 Sr/ 82 Rb, 68 Ge/ 68 Ga - and α emitters - 211 At. Among these radioisotopes, the Scandium 47 and the Copper 67 have a strong interest in targeted therapy. The optimization of their productions required a good knowledge of their cross-sections but also of all the contaminants created during irradiation. We launched on Arronax a program to measure these production cross-sections using the Stacked-Foils' technique. It consists in irradiating several groups of foils - target, monitor and degrader foils - and in measuring the produced isotopes by γ-spectrometry. The monitor - nat Cu or nat Ni - is used to correct beam loss whereas degrader foils are used to lower beam energy. We chose to study the nat Ti(p,X) 47 Sc and 68 Zn(p,2p) 67 Cu reactions. Targets are respectively natural Titanium foil - bought from Goodfellow - and enriched Zinc 68 deposited on Silver. In the latter case, Zn targets were prepared in-house - electroplating of 68 Zn - and a chemical separation between Copper and Gallium isotopes has to be made before γ counting. Cross-section values for more than 40 different reactions cross-sections have been obtained from 18 MeV to 68 MeV. A comparison with the Talys code is systematically done. Several parameters of theoretical models have been studied and we found that is not possible to reproduce faithfully all the cross-sections with a given set of parameters. (author)
Performing Neutron Cross-Section Measurements at RIA
International Nuclear Information System (INIS)
Ahle, L.E.
2003-01-01
The Rare Isotope Accelerator (RIA) is a proposed accelerator for the low energy nuclear physics community. Its goal is to understand the natural abundances of the elements heavier than iron, explore the nuclear force in systems far from stability, and study symmetry violation and fundamental physics in nuclei. To achieve these scientific goals, RIA promises to produce isotopes far from stability in sufficient quantities to allow experiments. It would also produce near stability isotopes at never before seen production rates, as much as 10 12 pps. Included in these isotopes are many that are important to stockpile stewardship, such as 87 Y, 146-50 Eu, and 231 Th. Given the expected production rates at RIA and a reasonably intense neutron source, one can expect to make ∼10 μg targets of nuclei with a half-life of ∼1 day. Thus, it will be possible at RIA to obtain experimental information on the neutron cross section for isotopes that have to date only been determined by theory. There are two methods to perform neutron cross-section measurements, prompt and delayed. The prompt method tries to measure each reaction as it happens. The exact technique employed will depend on the reaction of interest, (n,2n), (n,γ), (n,p), etc. The biggest challenge with this method is designing a detector system that can handle the gamma ray background from the target. The delayed method, which is the traditional radiochemistry method for determining the cross-section, irradiates the targets and then counts the reaction products after the fact. While this allows one to avoid the target background, the allowed fraction of target impurities is extremely low. This is especially true for the desired reaction product with the required impurity fraction on the order of 10 -9 . This is particularly problematic for (n,2n) and (n,γ) reactions, whose reaction production cannot be chemically separated from the target. In either case, the first step at RIA to doing these measurements is
International Nuclear Information System (INIS)
Pronyaev, V.; Carlson, A.D.; Capote Noy, R.; Wallner, A.
2011-03-01
The meeting participants have considered the progress in the measurement and evaluation of neutron cross sections and spectra which can be used as standard or reference data. This includes extension of the 197 Au(n,γ) standard to the energy range below 200 keV, 235 U(n th ,f) prompt fission neutron spectrum and neutron induced gamma-production cross sections. The work on this data development project for next two years has been agreed. (author)
International Nuclear Information System (INIS)
Blann, M.
1985-08-01
The Boltzmann master equation model has been applied to the question of precompound nucleon de-excitation of reactions induced by 10 to 100 MeV/nucleon (c.m.) heavy ions. Test systems of 16 O + 60 Ni and 27 Al + 86 Kr were selected. Experimental neutron spectra in coincidence with evaporation residue and fission fragments from the 20 Ne + 165 Ho system (due to Holub, et al.) were reproduced quite well by the master equation with exciton numbers between 20 and 23. Results show major fractions of the excitation and up to 35 nucleons removed during the coalescence-equilibration period. The linear momentum transfer predicted by the master equation is shown to be in good agreement with a broad range of data. Extension of the master equation to predict sub-threshold PI 0 production cross sections is shown to give satisfactory agreement with a large number of experimental results. 48 refs., 8 figs., 7 tabs
Energy Technology Data Exchange (ETDEWEB)
Lamirand, Vincent
2011-11-18
The response of a neutron detector, defined as the reading of the device per unit of incident fluence or dose, varies with neutron energy. The experimental determination of this variation, i.e. of the response function of this instrument, has to be performed by facilities producing monoenergetic neutron fields. These neutrons are commonly produced by interaction between accelerated ions (proton or deuteron) onto a thin target composed of a reactive layer deposited on a metallic backing. Using the {sup 7}Li(p, n), {sup 3}H(p, n), {sup 2}H(d, n) and {sup 3}H(d, n) reactions, monoenergetic neutrons are obtained between 120 keV and 20 MeV in the ion beam direction (0 deg.). To reach lower neutron energies, the angle of the measuring point with respect to the ion beam direction can be increased. However, this method presents several problems of neutron energy and fluence homogeneities over the detector surface, as well as an important increase of the scattered neutron contribution. Another solution is to investigate other nuclear reactions, as {sup 45}Sc(p, n) allowing to extend the neutron energy range down to 8 keV at 0 deg.. A complete study of this reaction and its cross section has been undertaken within the framework of a scientific cooperation between the laboratory of neutron metrology and dosimetry (IRSN, France), two European national metrological institutes, the National Physical Laboratory (UK) and the Physikalisch-Technische Bundesanstalt (Germany), and IRMM, the Institute for Reference Materials and Measurements (EC). In parallel, other possible reactions have been investigated: {sup 65}Cu(p, n), {sup 51}V(p, n), {sup 57}Fe(p, n), {sup 49}Ti(p, n), {sup 53}Cr(p, n) and {sup 37}Cl(p, n). They were compared in terms of neutron fluence and minimum energy of the produced neutrons. (author)
Cross section for inelastic neutron acceleration by 178Hfm2
International Nuclear Information System (INIS)
Karamyan, S.A.; Carroll, J.J.
2009-01-01
The scattering of thermal neutrons from isomeric nuclei may include events in which the outgoing neutrons have increased kinetic energy. This process has been called Inelastic Neutron Acceleration (INNA) and occurs when the final nucleus after emission of the neutron is left in a state with lower energy than that of the isomer. The result, therefore, is an induced depletion of the isomeric population to the ground state. A cascade of several gammas must accompany the neutron emission to release the high angular momentum of the initial isomeric state. INNA was previously observed in a few cases and the associated cross sections were only in modest agreement with theoretical estimates. The most recent measurement of an INNA cross section was σ INNA = (258 ± 58) b for neutron scattering by 177 Lu m . In the present work, an INNA cross section of σ INNA = 152 -36 +51 b was deduced from measurements of the total burn-up of the high-spin, four-quasiparticle isomer 178 Hf m2 during irradiation by thermal neutrons. Statistical estimates for the probability of different reaction channels past neutron absorption were used in the analysis, and the deduced σ INNA is compared to the theoretically predicted cross section
Nuclear fission and neutron-induced fission cross-sections
Energy Technology Data Exchange (ETDEWEB)
James, G.D.; Lynn, J.E.; Michaudon, A.; Rowlands, J.; de Saussure, G.
1981-01-01
A general presentation of current knowledge of the fission process is given with emphasis on the low energy fission of actinide nuclei and neutron induced fission. The need for and the required accuracy of fission cross section data in nuclear energy programs are discussed. A summary is given of the steps involved in fission cross section measurement and the range of available techniques. Methods of fission detection are described with emphasis on energy dependent changed and detector efficiency. Examples of cross section measurements are given and data reduction is discussed. The calculation of fission cross sections is discussed and relevant nuclear theory including the formation and decay of compound nuclei and energy level density is introduced. A description of a practical computation of fission cross sections is given.
International Nuclear Information System (INIS)
Duchemin, B.
1975-01-01
Cross-sections for the production of de-excitation γ rays following inelastic neutron scattering have been calculated, using the statistical model, and are given for natural chromium and nickel for neutron incident energy up to 10MeV [fr
Evaluation of neutron cross sections for 244Cm, 246Cm, and 248Cm
International Nuclear Information System (INIS)
Benjamin, R.W.; McCrosson, F.J.; Gettys, W.E.
1977-01-01
An evaluation of neutron cross sections for 244 246 248 Cm using the ENDF/B format is presented. Primary data input included differential measurements, integral measurements, nuclear model calculations, and reactor production experience
International Nuclear Information System (INIS)
Reupke, W.A.; Davidson, J.N.; Muir, D.W.
1982-01-01
The authors present algorithms, describe a computer program, and gives a computational procedure for the statistical consistency analysis of neutron cross-section data, S /SUB N/ calculations, and measured tritium production in 14-MeV neutron-driven integral assemblies. Algorithms presented include a reduced matrix manipulation technique suitable for manygroup, 14-MeV neutron transport calculations. The computer program incorporates these algorithms and is expanded and improved to facilitate analysis of such integral experiments. Details of the computational procedure are given for a natural lithium deuteride experiment performed at the Los Alamos National Laboratory. Results are explained in terms of calculated cross-section sensitivities and uncertainty estimates. They include a downward adjustment of the 7 Li(n,xt) 14-MeV cross section from 328 + or - 22 to 284 + or - 24 mb, which is supported by the trend of recent differential and integral measurements. It is concluded that with appropriate refinements, the techniques of consistency analysis can be usefully applied to the analysis of 14-MeV neutron-driven tritium production integral experiments
Binary and tertiary neutron induced reaction cross sections of chromium and iron
International Nuclear Information System (INIS)
Garg, S.B.
1989-01-01
Investigation has been carried out for the following binary and tertiary reaction cross-sections of Cr-52 and Fe-56: (n,p), (n,pn), (n,np), (n,α), (n, nα), (n, 2n) and (n, 3n), energy spectra of the emitted neutron, proton, α-particle and γ-rays, angle-energy correlated double differential cross-sections for the secondary emitted neutrons and total production cross-sections for neutron, hydrogen, helium and gamma-rays. 12 refs, 20 figs, 1 tab
Phenomenological dirac optical potential for neutron cross sections
Energy Technology Data Exchange (ETDEWEB)
Maruyama, Shin-ichi; Kitsuki, Hirohiko; Shigyo, Nobuhiro; Ishibashi, Kenji [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering
1997-03-01
Because of limitation on neutron-incident data, it is difficult to obtain global optical model potential for neutrons. In contrast, there are some global optical model potentials for proton in detail. It is interesting to convert the proton-incident global optical potentials into neutron-incident ones. In this study we introduce (N-Z)/A dependent symmetry potential terms into the global proton-incident optical potentials, and then obtain neutron-incident ones. The neutron potentials reproduce total cross sections in an acceptable degree. However, a comparison with potentials proposed by other authors brings about a confused situation in the sign of the symmetry terms. (author)
Evaluation of the 238U neutron total cross section
International Nuclear Information System (INIS)
Smith, A.; Poenitz, W.P.; Howerton, R.J.
1982-12-01
Experimental energy-averaged neutron total cross sections of 238 U were evaluated from 0.044 to 20.0 MeV using regorous numerical methods. The evaluated results are presented together with the associated uncertainties and correlation matrix. They indicate that this energy-averaged neutron total cross section is known to better than 1% over wide energy regions. There are somwewhat larger uncertainties at low energies (e.g., less than or equal to 0.2 MeV), near 8 MeV and above 15 MeV. The present evaluation is compard with values given in ENDF/B-V
Thermal neutron absorption cross section of small samples
International Nuclear Information System (INIS)
Nghiep, T.D.; Vinh, T.T.; Son, N.N.; Vuong, T.V.; Hung, N.T.
1989-01-01
A modified steady method for determining the macroscopic thermal neutron absorption cross section of small samples 500 cm 3 in volume is described. The method uses a moderating block of paraffin, Pu-Be neutron source emitting 1.1x10 6 n.s. -1 , SNM-14 counter and ordinary counting equipment. The interval of cross section from 2.6 to 1.3x10 4 (10 -3 cm 2 g -1 ) was measured. The experimental data are described by calculation formulae. 7 refs.; 4 figs
Neutron capture cross section measurements: case of lutetium isotopes
International Nuclear Information System (INIS)
Roig, O.; Meot, V.; Belier, G.
2011-01-01
The neutron radiative capture is a nuclear reaction that occurs in the presence of neutrons on all isotopes and on a wide energy range. The neutron capture range on Lutetium isotopes, presented here, illustrates the variety of measurements leading to the determination of cross sections. These measurements provide valuable fundamental data needed for the stockpile stewardship program, as well as for nuclear astrophysics and nuclear structure. Measurements, made in France or in United-States, involving complex detectors associated with very rare targets have significantly improved the international databases and validated models of nuclear reactions. We present results concerning the measurement of neutron radiative capture on Lu 173 , Lu 175 , Lu 176 and Lu 177m , the measurement of the probability of gamma emission in the substitution reaction Yb 174 (He 3 ,pγ)Lu 176 . The measurement of neutron cross sections on Lu 177m have permitted to highlight the process of super-elastic scattering
Cross sections for fast-neutron interaction with ytterbium isotopes
International Nuclear Information System (INIS)
Luo, Junhua; Liu, Rong; Jiang, Li; Ge, Suhong; Liu, Zhenlai; Sun, Guihua
2013-01-01
Highlights: ► The cross sections for the (n,x) reactions on ytterbium isotopes have been measured. ► Mono-energetic neutron beams using the D + T reaction; Energies: 13.5 and 14.8 MeV. ► Neutron cross-section measurements by means of the activation technique. ► Reference reactions 93 Nb(n,2n) 92m Nb and 27 (n,α) 24 Na. ► Data for 172 Yb(n,p) 172 Tm and 176 Yb(n,d * ) 175 Tm are reported for the first time. - Abstract: Measurements of (n,2n), (n,p), and (n,d * ) (The expression (n,d * ) cross section used in this work includes a sum of (n,d), (n,np) and (n,pn) cross sections.) reaction cross-sections on ytterbium isotopes have been carried out in the range of 13.5–14.8 MeV using the activation technique. The monoenergetic neutron beams were produced via the 3 H(d,n) 3 He reaction. The neutron energies of different directions were determined using the Nb/Zr method. Samples were activated along with along with Nb and Al monitor foils to determine the incident neutron flux. Data are reported for the following reactions: 168 Yb(n,2n) 167 Yb, 170 Yb(n,2n) 169m+g Yb, 176 Yb(n,2n) 175m+g Yb, 172 Yb(n,p) 172 Tm, 173 Yb(n,p) 173 Tm, 176 Yb(n,d * ) 175 Tm, 174 Yb(n,p) 174 Tm, and 176 Yb(n,p) 176 Tm. The experimentally deduced cross-sections are compared with the existing experimental data. Furthermore, theoretical statistical model, based on the Hauser–Feshbach formalism, have been carried out using the HFTT
Neutron Scattering Differential Cross Sections for 12C
Byrd, Stephen T.; Hicks, S. F.; Nickel, M. T.; Block, S. G.; Peters, E. E.; Ramirez, A. P. D.; Mukhopadhyay, S.; McEllistrem, M. T.; Yates, S. W.; Vanhoy, J. R.
2016-09-01
Because of the prevalence of its use in the nuclear energy industry and for our overall understanding of the interactions of neutrons with matter, accurately determining the effects of fast neutrons scattering from 12C is important. Previously measured 12C inelastic neutron scattering differential cross sections found in the National Nuclear Data Center (NNDC) show significant discrepancies (>30%). Seeking to resolve these discrepancies, neutron inelastic and elastic scattering differential cross sections for 12C were measured at the University of Kentucky Acceleratory Laboratory for incident neutron energies of 5.58, 5.83, and 6.04 MeV. Quasi mono-energetic neutrons were scattered off an enriched 12C target (>99.99%) and detected by a C6D6 liquid scintillation detector. Time-of-flight (TOF) techniques were used to determine scattered neutron energies and allowed for elastic/inelastic scattering distinction. Relative detector efficiencies were determined through direct measurements of neutrons produced by the 2H(d,n) and 3H(p,n) source reactions, and absolute normalization factors were found by comparing 1H scattering measurements to accepted NNDC values. This experimental procedure has been successfully used for prior neutron scattering measurements and seems well-suited to our current objective. Significant challenges were encountered, however, with measuring the neutron detector efficiency over the broad incident neutron energy range required for these measurements. Funding for this research was provided by the National Nuclear Security Administration (NNSA).
Measured and evaluated neutron cross sections of elemental bismuth
International Nuclear Information System (INIS)
Smith, A.; Guenther, P.; Smith, D.; Whalen, J.; Howerton, R.
1980-04-01
Neutron total cross sections of elemental bismuth are measured with broad resolution from 1.2 to 4.5 MeV to accuracies of approx. = 1%. Neutron-differential-elastic-scattering cross sections of bismuth are measured from 1.5 to 4.0 MeV at incident neutron energy intervals of approx.< 0.2 MeV over the scattered-neutron angular range approx. = 20 to 160 deg. Differential neutron cross sections for the excitation of observed states in bismuth at 895 +- 12, 1606 +- 14, 2590 +- 15, 2762 +- 29, 3022 +- 21, and 3144 +- 15 keV are determined at incident neutron energies up to 4.0 MeV. An optical-statistical model is deduced from the measured values. This model, the present experimental results, and information available elsewhere in the literature are used to construct a comprehensive evaluated nuclear data file for elemental bismuth in the ENDF format. The evaluated file is particularly suited to the neutronic needs of the fusion-fission hybrid designer. 87 references, 10 figures, 6 tables
Fast-neutron total and scattering cross sections of niobium
Energy Technology Data Exchange (ETDEWEB)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-07-01
Neutron total cross sections of niobium were measured from approx. = 0.7 to 4.5 MeV at intervals of less than or equal to 50 keV with broad resolution. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 4.0 MeV at intervals of 0.1 to 0.2 MeV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Inelastically-scattered neutrons, corresponding to the excitation of levels at: 788 +- 23, 982 +- 17, 1088 +- 27, 1335 +- 35, 1504 +- 30, 1697 +- 19, 1971 +- 22, 2176 +- 28, 2456 +- (.), and 2581 +- (.) keV, were observed. An optical-statistical model, giving a good description of the observables, was deduced from the measured differential-elastic-scattering cross sections. The experimental-results were compared with the respective evaluated quantities given in ENDF/B-V.
Fast-neutron total and scattering cross sections of niobium
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-07-01
Neutron total cross sections of niobium were measured from approx. = 0.7 to 4.5 MeV at intervals of less than or equal to 50 keV with broad resolution. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 4.0 MeV at intervals of 0.1 to 0.2 MeV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 degrees. Inelastically-scattered neutrons, corresponding to the excitation of levels at: 788 +- 23, 982 +- 17, 1088 +- 27, 1335 +- 35, 1504 +- 30, 1697 +- 19, 1971 +- 22, 2176 +- 28, 2456 +- (.), and 2581 +- (.) keV, were observed. An optical-statistical model, giving a good description of the observables, was deduced from the measured differential-elastic-scattering cross sections. The experimental-results were compared with the respective evaluated quantities given in ENDF/B-V
International Nuclear Information System (INIS)
Meadows, J.W.; Smith, D.L.
1980-05-01
Experimental methods related to the production of neutrons for cross section studies at the Argonne Fast-Neutron Generator are reviewed. Target assemblies commonly employed in these measurements are described, and some of the relevant physical properties of the neutron source reactions are discussed. Various measurements have been performed to ascertain knowledge about these source reaction that is required for cross section data analysis purposes. Some results from these studies are presented, and a few specific examples of neutron-source-related corrections to cross section data are provided. 16 figures, 3 tables
ACTIV87 Fast neutron activation cross section file 1987
International Nuclear Information System (INIS)
Manokhin, V.N.; Pashchenko, A.B.; Plyaskin, V.I.; Bychkov, V.M.; Pronyaev, V.G.; Schwerer, O.
1989-10-01
This document summarizes the content of the Fast Neutron Activation Cross Section File based on data from different evaluated data libraries and individual evaluations in ENDF/B-5 format. The entire file or selective retrievals from it are available on magnetic tape, free of charge, from the IAEA Nuclear Data Section. (author)
Nuclear structure effects on calculated fast neutron reaction cross sections
International Nuclear Information System (INIS)
Avrigeanu, V.
1992-01-01
The importance of accurate low-lying level schemes for reaction cross section calculation and need for microscopically calculated levels are proved with reference to fast neutron induced reactions in the A = 50 atomic mass range. The uses of the discrete levels both for normalization of phenomenological level density approaches and within Hauser-Feshbach calculations are discussed in this respect. (Author)
Measured and evaluated fast neutron cross sections of elemental nickel
International Nuclear Information System (INIS)
Guenther, P.; Smith, A.; Smith, D.; Whalen, J.; Howerton, R.
1975-07-01
Fast neutron total and scattering cross sections of elemental nickel are measured. Differential elastic scattering cross sections are determined from incident energies of 0.3 to 4.0 MeV. The cross sections for the inelastic neutron excitation of states at: 1.156 +- 0.015, 1.324 +- 0.015, 1.443 +- 0.015, 2.136 +- 0.013, 2.255 +- 0.030, 2.449 +- 0.030, 2.614 +- 0.020 and 2.791 +- 0.025 MeV are measured to incident neutron energies of 4.0 MeV. The total neutron cross sections are determined from 0.25 to 5.0 MeV. The experimental results are discussed in the context of optical and statistical models. It is shown that resonance width-fluctuation and correlation effects are significant. The present experimental and theoretical results, together with previously reported values, are used to construct a comprehensive evaluated elemental data file in the ENDF format. Some comparisons are made with previously reported evaluated files. In addition, some selected reactions which are widely used in dosimetry and other applications are presented as supplemental evaluated isotopic-data files. The numerical quantities are presented in tabular form. (3 tables, 29 figures)
Resonance parameters for measured keV neutron capture cross sections
Energy Technology Data Exchange (ETDEWEB)
Musgrove, A.R. de L
1969-05-01
All available neutron capture cross sections in the keV region ({approx} to 100 keV) have been fitted with resonance parameters. Capture cross sections for nuclides with reasonably well known average s-wave parameters, but no measured cross section, have been calculated and tabulated using p-and d- wave strength functions interpolated between fitted values. Several of these nuclides are of interest in the theory of slow nucleosynthesis of heavy elements in stars, and the product of cosmic abundance (due to the s-process) and capture cross section at 30 keV has been plotted versus mass number. (author)
The determination of thermal neutron cross section of 81Br
International Nuclear Information System (INIS)
Kovacs, Luciana; Zamboni, Cibele B.; Dalaqua Junior, Leonardo
2009-01-01
In this investigation several standard materials were used to determine the thermal neutron cross section of 81 Br. This nuclear parameter is an important data to perform several quantitative investigations, mainly in medical area. In other to confirm and to reduce the uncertainty, a new measurement was preformed using thermal neutron at IEA-R1 nuclear reactor of IPEN/CNEN-SP. The result obtained is compatible with the tabulated value and present small uncertainly. (author)
Fast neutron capture cross section facility at Cadarache
International Nuclear Information System (INIS)
Le Rigoleur, C.; Arnaud, A.
1975-01-01
The total energy weighting technique has been applied to measure absolute fast neutron capture cross section at Cadarache. We use a non hydrogeneous liquid scintillator to detect the gamma from the cascade. The neutron flux is measured with a B 10 INa(Tl) detector or Li 6 glass scintillator of well known efficiency. Time of flight technique is used with on line digital computer data processing. (orig.) [de
Removal cross section for 14 mev neutrons in constructional materials
International Nuclear Information System (INIS)
Vasvary, L.; Divos, F.; Peto, G.; Csikai, J.; Mumba, N.K.
1985-01-01
Using flight time difference the direct and scattered neutrons and gammas produced in the target head and samples were separated. With this method the attenuation of primary neutrons and gammas originating from the target head has been studied. Thickness dependence of the secondary gamma yield from extended samples of Al, Fe, Pb, paraffin and reinforced concrete was also measured. Results indicate a geometry dependence of the removal cross sections
Nuclear Astrophysics and Neutron Cross Section Measurements Using the ORELA
Energy Technology Data Exchange (ETDEWEB)
Winters, R. R.
2000-08-25
This is the final report for a research program which has been continuously supported by the AEC, ERDA, or USDOE since 1973. The neutron total and capture cross sections for n + {sup 88}Sr have been measured over the neutron energy range 100 eV to 1 MeV. The report briefly summaries our results and the importance of this work for nucleosynthesis and the optical model.
Status of neutron cross sections for reactor dosimetry
International Nuclear Information System (INIS)
Vlasov, M.F.; Fabry, A.; McElroy, W.N.
1977-03-01
The status of current international efforts to develop standardized sets of evaluated energy-dependent (differential) neutron cross sections for reactor dosimetry is reviewed. The status and availability of differential data are considered, some recent results of the data testing of the ENDF/B-IV dosimetry file using 252 Cf and 235 U benchmark reference neutron fields are presented, and a brief review is given of the current efforts to characterize and identify dosimetry benchmark radiation fields
Nuclear Astrophysics and Neutron Cross Section Measurements Using the ORELA
International Nuclear Information System (INIS)
Winters, R. R.
2000-01-01
This is the final report for a research program which has been continuously supported by the AEC, ERDA, or USDOE since 1973. The neutron total and capture cross sections for n + 88 Sr have been measured over the neutron energy range 100 eV to 1 MeV. The report briefly summaries our results and the importance of this work for nucleosynthesis and the optical model
Neutron-absorption cross section of sodium-22
International Nuclear Information System (INIS)
Rundberg, R.; Elgart, M.F.; Finston, H.L.; Williams, E.T.; Bond, A.H. Jr.
1975-01-01
A simple method for determining the neutron-absorption cross sections for radionuclides produced and consumed in a reactor-neutron flux is described. Data were obtained for 22 Na which, through application of Westcott's procedure, yielded the following: sigma 0 = 51.5 +- 3.1 kbarns, s 0 = 2.3 +- 0.1, and Σ' = 100 +- 10 kbarns. (3 tables) (U.S.)
International Nuclear Information System (INIS)
Ford, W.E. III; Arwood, J.W.; Greene, N.M.; Moses, D.L.; Petrie, L.M.; Primm, R.T. III; Slater, C.O.; Westfall, R.M.; Wright, R.Q.
1990-09-01
Pseudo-problem-independent, multigroup cross-section libraries were generated to support Advanced Neutron Source (ANS) Reactor design studies. The ANS is a proposed reactor which would be fueled with highly enriched uranium and cooled with heavy water. The libraries, designated ANSL-V (Advanced Neutron Source Cross Section Libraries based on ENDF/B-V), are data bases in AMPX master format for subsequent generation of problem-dependent cross-sections for use with codes such as KENO, ANISN, XSDRNPM, VENTURE, DOT, DORT, TORT, and MORSE. Included in ANSL-V are 99-group and 39-group neutron, 39-neutron-group 44-gamma-ray-group secondary gamma-ray production (SGRP), 44-group gamma-ray interaction (GRI), and coupled, 39-neutron group 44-gamma-ray group (CNG) cross-section libraries. The neutron and SGRP libraries were generated primarily from ENDF/B-V data; the GRI library was generated from DLC-99/HUGO data, which is recognized as the ENDF/B-V photon interaction data. Modules from the AMPX and NJOY systems were used to process the multigroup data. Validity of selected data from the fine- and broad-group neutron libraries was satisfactorily tested in performance parameter calculations
Average cross sections calculated in various neutron fields
International Nuclear Information System (INIS)
Shibata, Keiichi
2002-01-01
Average cross sections have been calculated for the reactions contained in the dosimetry files, JENDL/D-99, IRDF-90V2, and RRDF-98 in order to select the best data for the new library IRDF-2002. The neutron spectra used in the calculations are as follows: 1) 252 Cf spontaneous fission spectrum (NBS evaluation), 2) 235 U thermal fission spectrum (NBS evaluation), 3) Intermediate-energy Standard Neutron Field (ISNF), 4) Coupled Fast Reactivity Measurement Facility (CFRMF), 5) Coupled thermal/fast uranium and boron carbide spherical assembly (ΣΣ), 6) Fast neutron source reactor (YAYOI), 7) Experimental fast reactor (JOYO), 8) Japan Material Testing Reactor (JMTR), 9) d-Li neutron spectrum with a 2-MeV deuteron beam. The items 3)-7) represent fast neutron spectra, while JMTR is a light water reactor. The Q-value for the d-Li reaction mentioned above is 15.02 MeV. Therefore, neutrons with energies up to 17 MeV can be produced in the d-Li reaction. The calculated average cross sections were compared with the measurements. Figures 1-9 show the ratios of the calculations to the experimental data which are given. It is found from these figures that the 58 Fe(n, γ) cross section in JENDL/D-99 reproduces the measurements in the thermal and fast reactor spectra better than that in IRDF-90V2. (author)
Measurement of neutron captured cross-sections in 1-2 MeV
Energy Technology Data Exchange (ETDEWEB)
Kim, Gi Dong; Kim, Young Sek; Kim, Jun Kon; Yang, Tae Keun [Korea Institutes of Geoscience and Mineral Resources, Taejeon (Korea)
2001-04-01
The measurement of neutron captured reaction cross sections was performed to build the infra system for the production of nuclear data. MeV neutrons were produced with TiT target and {sup 3}T(p,n){sup 3}He reaction. The characteristics of TiT thin film was analyzed with ERD-TOF and RBS. The results was published at Journal of the Korea Physical Society (SCI registration). The energy, the energy spread and the flux of the produced neutron were measured. The neutron excitation functions of {sup 12}C and {sup 16}O were obtained to confirm the neutron energy and neutron energy spread. The neutron energy spread found to be 1.3 % at the neutron energy of 2.077 MeV. The {sup 197}Au(n,{gamma}) reaction was performed to obtain the nerutron flux. The maximum neutron flux found to be 1 x 10{sup 8} neutrons/sec at the neutron energy of 2 MeV. The absolute efficiency of liquid scintillation detector was obtained in the neutron energy of 1 - 2 MeV. The fast neutron total reaction cross sections of Cu, Fe, and Au were measured with sample in-out method. Also the neutron captured reaction cross sections of {sup 63}Cu were measured with fast neutron activation method. The measurement of neutron total reaction cross sections and the neutron captured reaction cross sections with fast neutrons were first tried in Korea. The beam pulsing system was investigated and the code of calculating the deposition spectrums for primary gamma rays was made to have little errors at nuclear data. 25 refs., 28 figs., 14 tabs. (Author)
Pion production cross sections and associated parameters
International Nuclear Information System (INIS)
Bradbury, J.N.
1985-01-01
Negative pions have been used for radiotherapy at the meson factories LAMPF (USA), SIN (Switzerland), and TRIUMF (Canada) and have been planned for use at new meson facilities under construction (USSR) and at proposed dedicated medical facilities. Providing therapeutically useful dose rates of pions requires a knowledge of the pion production cross sections as a function of primary proton energy (500 to 1000 MeV), pion energy (less than or equal to100 MeV), production angle, and target material. The current status of the data base in this area is presented including theoretical guidelines for extrapolation purposes. The target material and geometry, as well as the proton and pion beam parameters, will affect the electron (and muon) contamination in the beam which may have an important effect on both the LET characteristics of the dose and the dose distribution. In addition to cross-section data, channel characteristics such as length of pion trajectory, solid-angle acceptance, and momentum analysis will affect dose rate, distribution, and quality. Such considerations are briefly addressed in terms of existing facilities and proposed systems. 16 refs., 6 figs
Neutron capture cross section of /sup 197/Au: A standard for stellar nucleosynthesis
International Nuclear Information System (INIS)
Ratynski, W.; Kaeppeler, F.
1988-01-01
We have measured the neutron capture cross section of gold using the 7 Li(p,n) 7 Be reaction for neutron production. This reaction not only provides the integrated neutron flux via the 7 Be activity of the target, but also allows for the simulation of a Maxwellian neutron energy spectrum at kT = 25 keV. As this spectrum is emitted in a forward cone of 120 0 opening angle, the cross section can be measured in good geometry and independent of any other standard. Systematic uncertainties were studied experimentally in a series of activations. The final stellar cross section at kT = 25 keV was found to be 648 +- 10 mb, and extrapolation to the common s-process temperature kT = 30 keV yields 582 +- 9 mb. This result is used for renormalization of a number of cross sections which had been measured relative to gold
View-CXS neutron and photon cross-sections viewer
International Nuclear Information System (INIS)
Subbaiah, K.V.; Sunil Sunny, C.
2004-01-01
A graphical user-friendly interface is developed in Visual Basic (VB)-6 to view the variation of neutron and photon interaction cross-sections of different isotopes as a function of energy. VB subroutines developed read the binary data files of cross-sections created in MCNP-ACE (Briesmeister, J.F., 1993. MCNP - a general purpose Monte Carlo N-Particle Transport code. Version 4A. LANL, USA), ANISN-DLC (Engle W.W. Jr., 1967, A User's Manual for ANISN, K-1693; ORNL, 1974. 100 group neutron cross section data based on ENDF/B-III. Oak Ridge National Laboratory, USA) and KENO-AMPX (Petrie, L.M., Landers, N.F., 1984 KENO-Va- An Improved Monte Carlo Criticality Program with Super Grouping. RSICC-CCC-548, USA) formats using LAHEY-77 Fortran Compiler. The information on isotopes present in each library will be displayed with the help of database files prepared using Micro-Soft ACESS. The cross-section data can be viewed in different presentation styles namely, line graphs, bar graphs, histograms etc., with different color and symbol options. The cross-section plots generated can be saved as Bit-Map file to embed in any other text files. This software enables inter comparison of cross-sections from different type of libraries for isotopes as well as mixtures. Provision is made to view the cross-sections for nuclear reactions such as (n,γ), (n,f), (n,α), etc. The software can be obtained from Radiation Safety Information and Computational Centre (RSICC), ORNL, USA with the code package identification number PSR-514. The software package needs a hard disk space of about 80 MB when installed and works in WINDOWS-95/98/2000 operating systems
AFCI-2.0 Neutron Cross Section Covariance Library
Energy Technology Data Exchange (ETDEWEB)
Herman, M.; Herman, M; Oblozinsky, P.; Mattoon, C.M.; Pigni, M.; Hoblit, S.; Mughabghab, S.F.; Sonzogni, A.; Talou, P.; Chadwick, M.B.; Hale, G.M.; Kahler, A.C.; Kawano, T.; Little, R.C.; Yount, P.G.
2011-03-01
The cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The project builds on two covariance libraries developed earlier, with considerable input from BNL and LANL. In 2006, international effort under WPEC Subgroup 26 produced BOLNA covariance library by putting together data, often preliminary, from various sources for most important materials for nuclear reactor technology. This was followed in 2007 by collaborative effort of four US national laboratories to produce covariances, often of modest quality - hence the name low-fidelity, for virtually complete set of materials included in ENDF/B-VII.0. The present project is focusing on covariances of 4-5 major reaction channels for 110 materials of importance for power reactors. The work started under Global Nuclear Energy Partnership (GNEP) in 2008, which changed to Advanced Fuel Cycle Initiative (AFCI) in 2009. With the 2011 release the name has changed to the Covariance Multigroup Matrix for Advanced Reactor Applications (COMMARA) version 2.0. The primary purpose of the library is to provide covariances for AFCI data adjustment project, which is focusing on the needs of fast advanced burner reactors. Responsibility of BNL was defined as developing covariances for structural materials and fission products, management of the library and coordination of the work; LANL responsibility was defined as covariances for light nuclei and actinides. The COMMARA-2.0 covariance library has been developed by BNL-LANL collaboration for Advanced Fuel Cycle Initiative applications over the period of three years, 2008-2010. It contains covariances for 110 materials relevant to fast reactor R&D. The library is to be used together with the ENDF/B-VII.0 central values of the latest official release of US files of evaluated neutron cross sections. COMMARA-2.0 library contains neutron cross section covariances for 12 light nuclei (coolants and moderators), 78 structural
AFCI-2.0 Neutron Cross Section Covariance Library
International Nuclear Information System (INIS)
Herman, M.; Oblozinsky, P.; Mattoon, C.M.; Pigni, M.; Hoblit, S.; Mughabghab, S.F.; Sonzogni, A.; Talou, P.; Chadwick, M.B.; Hale, G.M.; Kahler, A.C.; Kawano, T.; Little, R.C.; Yount, P.G.
2011-01-01
The cross section covariance library has been under development by BNL-LANL collaborative effort over the last three years. The project builds on two covariance libraries developed earlier, with considerable input from BNL and LANL. In 2006, international effort under WPEC Subgroup 26 produced BOLNA covariance library by putting together data, often preliminary, from various sources for most important materials for nuclear reactor technology. This was followed in 2007 by collaborative effort of four US national laboratories to produce covariances, often of modest quality - hence the name low-fidelity, for virtually complete set of materials included in ENDF/B-VII.0. The present project is focusing on covariances of 4-5 major reaction channels for 110 materials of importance for power reactors. The work started under Global Nuclear Energy Partnership (GNEP) in 2008, which changed to Advanced Fuel Cycle Initiative (AFCI) in 2009. With the 2011 release the name has changed to the Covariance Multigroup Matrix for Advanced Reactor Applications (COMMARA) version 2.0. The primary purpose of the library is to provide covariances for AFCI data adjustment project, which is focusing on the needs of fast advanced burner reactors. Responsibility of BNL was defined as developing covariances for structural materials and fission products, management of the library and coordination of the work; LANL responsibility was defined as covariances for light nuclei and actinides. The COMMARA-2.0 covariance library has been developed by BNL-LANL collaboration for Advanced Fuel Cycle Initiative applications over the period of three years, 2008-2010. It contains covariances for 110 materials relevant to fast reactor R and D. The library is to be used together with the ENDF/B-VII.0 central values of the latest official release of US files of evaluated neutron cross sections. COMMARA-2.0 library contains neutron cross section covariances for 12 light nuclei (coolants and moderators), 78
Fast-neutron scattering cross sections of elemental zirconium
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.
1982-12-01
Differential neturon-elastic-scattering cross sections of elemental zirconium are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV. Inelastic-neutron-scattering cross sections corresponding to the excitation of levels at observed energies of: 914 +- 25, 1476 +- 37, 1787 +- 23, 2101 +- 26, 2221 +- 17, 2363 +- 14, 2791 +- 15 and 3101 +- 25 keV are determined. The experimental results are interpreted in terms of the optical-statistical model and are compared with corresponding quantities given in ENDF/B-V
International Nuclear Information System (INIS)
Pashchenko, A.B.
1996-12-01
The present report describes the results of the IAEA Co-ordinated Research Programme (CRP) on ''Improvements of Measurements, Theoretical Computation and Evaluations of Neutron Induced Helium Production Cross Sections''. Summarized is the progress achieved under the CRP in the following areas: measurements of α-production cross sections for structural materials, theoretical computations at (nα) cross sections; measurements of activation cross sections; and improvement of experimental methods for (n,α) investigations. The status report gives also short summaries on the work of each laboratory which contributed to the results of the CRP. Attached is the list of program members and participants of CRP meetings. (author). Refs, 2 figs, 1 tab
International Nuclear Information System (INIS)
Trofimov, Yu.N.
1991-01-01
The radiative neutron capture cross-section of nuclei has been derived as a function of neutron excess on the basis of the exponential dependence of the cross-section on the reaction energy. It is shown that unknown cross-sections of stable and radioactive nuclei may be evaluated by using the isotonic and isotopic dependence together with available reference cross-section measurements. (author). 4 refs, 3 figs
Neutron total cross section measurements on 249Cf
International Nuclear Information System (INIS)
Carlton, R.F.; Harvey, J.A.; Hill, N.W.; Pandey, M.S.; Benjamin, R.W.
1979-01-01
Neutron total cross section measurements were performed on a sample of 249 Cf (5.65 mg total weight) with the ORELA as a source of pulsed neutrons. The sample, the inverse thickness of which was 1542 barns/atom, consisted of 85.3% 249 Cf and 14.4% 249 Bk, and was cooled to liquid nitrogen temperature. Analyses were also made of data from a thin sample (l/n = 17430) of 65% 249 Cf in the region of the large fission resonance at 0.7 eV. Fifty-five resonances in 249 Cf were observed and analyzed over the energy range 0.1 eV to 90 eV by use of an R-matrix multilevel formalism. The resonance parameters obtained were used to determine the level spacing and the s-wave neutron and fission strength functions. Thermal total cross section measurements were also performed. 5 figures, 3 tables
Neutron cross section standards and instrumentation: Annual report
International Nuclear Information System (INIS)
1987-01-01
This annual report from the National Bureau of Standards contains a summary of the results of the Neutron Cross Section Standards and Instrumentation Program. The technical measurements for the past year are given along with the proposed program and budget needs for the next three years. The neutron standards measurements have concentrated on the most important 235 U(n,f) cross section in the thermal to 20 MeV energy range along with the development of neutron detectors required for these measurements. The NBS measurements have made a significant contribution to the improvement in the understanding of this reaction. Measurements were performed with numerous neutron detectors at overlapping energies and at different neutron sources in order to reduce the systematic errors to achieve the required accuracy in this important neutron standard. Significant progress was also made in the development of a detector to utilize the 3 He(n,p) reaction as a standard in the eV to MeV energy region. Improvements in data acquisition systems as well as additional studies of advanced neutron sources were accomplished. Contacts with private industry were maintained and coordination of the neutron standards evaluation was continued. The report also includes biographical listings of the research staff along with copies of a few of our recent publications. 13 figs., 1 tab
Energy Technology Data Exchange (ETDEWEB)
Holmqvist, B; Wiedling, T
1969-06-15
Neutron elastic scattering cross section measurements have been going on for a long period at the Studsvik Van de Graaff laboratory. The cross sections of a range of elements have been investigated in the energy interval 1.5 to 8 MeV. The experimental data have been compared with cross sections calculated with the optical model when using a local nuclear potential.
Microscopic description of production cross sections including deexcitation effects
Sekizawa, Kazuyuki
2017-07-01
Background: At the forefront of the nuclear science, production of new neutron-rich isotopes is continuously pursued at accelerator laboratories all over the world. To explore the currently unknown territories in the nuclear chart far away from the stability, reliable theoretical predictions are inevitable. Purpose: To provide a reliable prediction of production cross sections taking into account secondary deexcitation processes, both particle evaporation and fission, a new method called TDHF+GEMINI is proposed, which combines the microscopic time-dependent Hartree-Fock (TDHF) theory with a sophisticated statistical compound-nucleus deexcitation model, GEMINI++. Methods: Low-energy heavy ion reactions are described based on three-dimensional Skyrme-TDHF calculations. Using the particle-number projection method, production probabilities, total angular momenta, and excitation energies of primary reaction products are extracted from the TDHF wave function after collision. Production cross sections for secondary reaction products are evaluated employing GEMINI++. Results are compared with available experimental data and widely used grazing calculations. Results: The method is applied to describe cross sections for multinucleon transfer processes in 40Ca+124Sn (Ec .m .≃128.54 MeV ), 48Ca+124Sn (Ec .m .≃125.44 MeV ), 40Ca+208Pb (Ec .m .≃208.84 MeV ), 58Ni+208Pb (Ec .m .≃256.79 MeV ), 64Ni+238U (Ec .m .≃307.35 MeV ), and 136Xe+198Pt (Ec .m .≃644.98 MeV ) reactions at energies close to the Coulomb barrier. It is shown that the inclusion of secondary deexcitation processes, which are dominated by neutron evaporation in the present systems, substantially improves agreement with the experimental data. The magnitude of the evaporation effects is very similar to the one observed in grazing calculations. TDHF+GEMINI provides better description of the absolute value of the cross sections for channels involving transfer of more than one proton, compared to the grazing
Evaluation and calculation of neutron transactinide cross-sections
International Nuclear Information System (INIS)
Konshin, V.A.
1980-01-01
This paper reviews the state of the art of nuclear theory and its application to the evaluation and calculation of neutron reaction cross sections of transactinium isotopes. In particular, the paper describes the current evaluation of the total files of neutron reaction data for 240 Pu and 241 Pu in the energy range between 10 -5 eV and 15 MeV based on a thorough analysis of available experimental data and on the use of modern theoretical concepts, and the work in progress on the evaluation of the total neutron reaction data file for 242 Pu and 241 Am. (author)
Neutron halo in 14B studied via reaction cross sections
International Nuclear Information System (INIS)
Fukuda, M.; Tanaka, M.; Iwamoto, K.; Wakabayashi, S.; Yaguchi, M.; Ohno, J.; Morita, Y.; Kamisho, Y.; Mihara, M.; Matsuta, K.; Nishimura, D.; Suzuki, S.; Nagashima, M.; Ohtsubo, T.; Ogura, T.; Abe, K.; Kikukawa, N.; Sakai, T.; Sera, D.; Takechi, M.; Izumikawa, T.; Suzuki, T.; Yamaguchi, T.; Sato, K.; Furuki, H.; Miyazawa, S.; Ichihashi, N.; Kohno, J.; Yamaki, S.; Kitagawa, A.; Sato, S.; Fukuda, S.
2014-01-01
Reaction cross sections (σ R ) for the neutron-rich nucleus 14 B on Be, C, and Al targets have been measured at several energies in the intermediate energy range of 45-120 MeV/nucleon. The present experimental σ R show a significant enhancement relative to the systematics of stable nuclei. The nucleon density distribution was deduced through the fitting procedure with the modified Glauber calculation. The necessity of a long tail in the density distribution was found, which is consistent with the valence neutron in 2s 1/2 orbital with the small empirical one-neutron separation energy in 14 B. (authors)
Nuclear fission and neutron-induced fission cross-sections
James, G D; Michaudon, A; Michaudon, A; Cierjacks, S W; Chrien, R E
2013-01-01
Nuclear Fission and Neutron-Induced Fission Cross-Sections is the first volume in a series on Neutron Physics and Nuclear Data in Science and Technology. This volume serves the purpose of providing a thorough description of the many facets of neutron physics in different fields of nuclear applications. This book also attempts to bridge the communication gap between experts involved in the experimental and theoretical studies of nuclear properties and those involved in the technological applications of nuclear data. This publication will be invaluable to those interested in studying nuclear fis
Theory of neutron resonance cross sections for safety applications
International Nuclear Information System (INIS)
Froehner, F.H.
1992-09-01
Neutron resonances exert a strong influence on the behaviour of nuclear reactors, especially on their response to the temperature changes accompanying power excursions, and also on the efficiency of shielding materials. The relevant theory of neutron resonance cross sections including the practically important approximations is reviewed, both for the resolved and the unresolved resonance region. Numerical techniques for Doppler broadening of resonances are presented, and the construction of group constants and especially of self-shielding factors for neutronics calculations is outlined. (orig.) [de
International Nuclear Information System (INIS)
Hlavac, S.; Benovic, M.; Betak, E.; Dostal, L.; Turzo, I.; Simakov, S.P.
1999-01-01
We measured cross section of prompt discrete γ ray transitions produced in 14.6 MeV neutron interactions with 23 Na, 27 Al, 28 Si, 31 P 39 K, 51 V, 55 Mn and nat Mo. Cross sections were measured relative to reference cross sections with low uncertainties using a dedicated experimental setup with a 244 cm 3 HPGe photon detector and associated α particle timing. In addition to photons from inelastic scattering we observed discrete transitions from (n,p), (n,n'p), (n,α), and (n,2n) reactions. Discrete γ transitions in 28 Si(n,n'p) 27 Al, the majority of transitions in Mn+n, and all transitions in Mo+n reactions were observed for the first time. Where available, our experimental data are compared with existing data. This comparison shows that existing data are in disagreement with present data in many cases, a finding which stresses the necessity of standardization of measurement procedure. For some reactions we compared our results with statistical model predictions, calculated with the advanced code GNASH as well as with a technically simpler code DEGAS, developed in our lab. In several instances, mostly in reactions where only a single nucleon is emitted, the statistical model calculations describe the observed cross sections well. In other cases, where several nucleons are emitted sequentially or in a cluster, the agreement is less satisfactory. (author)
Thermal neutron scattering cross sections of beryllium and magnesium oxides
International Nuclear Information System (INIS)
Al-Qasir, Iyad; Jisrawi, Najeh; Gillette, Victor; Qteish, Abdallah
2016-01-01
Highlights: • Neutron thermalization in BeO and MgO was studied using Ab initio lattice dynamics. • The BeO phonon density of states used to generate the current ENDF library has issues. • The BeO cross sections can provide a more accurate ENDF library than the current one. • For MgO an ENDF library is lacking: a new accurate one can be built from our results. • BeO is a better filter than MgO, especially when cooled down to 77 K. - Abstract: Alkaline-earth beryllium and magnesium oxides are fundamental materials in nuclear industry and thermal neutron scattering applications. The calculation of the thermal neutron scattering cross sections requires a detailed knowledge of the lattice dynamics of the scattering medium. The vibrational properties of BeO and MgO are studied using first-principles calculations within the frame work of the density functional perturbation theory. Excellent agreement between the calculated phonon dispersion relations and the experimental data have been obtained. The phonon densities of states are utilized to calculate the scattering laws using the incoherent approximation. For BeO, there are concerns about the accuracy of the phonon density of states used to generate the current ENDF/B-VII.1 libraries. These concerns are identified, and their influences on the scattering law and inelastic scattering cross section are analyzed. For MgO, no up to date thermal neutron scattering cross section ENDF library is available, and our results represent a potential one for use in different applications. Moreover, the BeO and MgO efficiencies as neutron filters at different temperatures are investigated. BeO is found to be a better filter than MgO, especially when cooled down, and cooling MgO below 77 K does not significantly improve the filter’s efficiency.
International Nuclear Information System (INIS)
Okumura, Keisuke; Nagaya, Yasunobu
2011-09-01
In May 2010, JENDL-4.0 was released from Japan Atomic Energy Agency as the updated Japanese Nuclear Data Library. It was processed by the nuclear data processing system LICEM and an arbitrary-temperature neutron cross section library MVPlib - nJ40 was produced for the neutron and photon transport calculation code MVP based on the continuous-energy Monte Carlo method. The library contains neutron cross sections for 406 nuclides on the free gas model, thermal scattering cross sections, and cross sections of pseudo fission products for burn-up calculations with MVP. Criticality benchmark calculations were carried out with MVP and MVPlib - nJ40 for about 1,000 cases of critical experiments stored in the hand book of International Criticality Safety Benchmark Evaluation Project (ICSBEP), which covers a wide variety of fuel materials, fuel forms, and neutron spectra. We report all comparison results (C/E values) of effective neutron multiplication factors between calculations and experiments to give a validation data for the prediction accuracy of JENDL-4.0 for criticalities. (author)
Fast-neutron scattering cross sections of elemental silver
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.
1982-05-01
Differential neutron elastic- and inelastic-scattering cross sections of elemental silver are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV and at 10 to 20 scattering angles distributed between 20 and 160 0 . Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at; 328 +- 13, 419 +- 50, 748 +- 25, 908 +- 26, 1150 +- 38, 1286 +- 25, 1507 +- 20, 1623 +- 30, 1835 +- 20 and 1944 +- 26 keV. The experimental results are used to derive an optical-statistical model that provides a good description of the observed cross sections. The measured values are compared with corresponding quantities given in ENDF/B-V
Neutron cross section standards and instrumentation. Annual report
Energy Technology Data Exchange (ETDEWEB)
Wasson, O.A.
1993-07-01
The objective of this interagency program is to provide accurate neutron interaction measurements for the US Department of Energy nuclear programs which include waste disposal, fusion, safeguards, defense, fission, and personnel protection. These measurements are also useful to other energy programs which indirectly use the unique properties of the neutron for diagnostic and analytical purposes. The work includes the measurement of reference cross sections and related neutron data employing unique facilities and capabilities at NIST and other laboratories as required; leadership and participation in international intercomparisons and collaborations; the preservation of standard reference deposits and the development of improved neutron detectors and measurement methods. A related and essential element of the program is critical evaluation of neutron interaction data including international coordinations. Data testing of critical data for important applications is included. The program is jointly supported by the Department of Energy and the National Institute of Standards and Technology. This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the third year of this three-year interagency agreement. The proposed program and required budget for the following three years are also presented. The program continues the shifts in priority instituted in order to broaden the program base.
Neutron cross section standards and instrumentation. Annual report
International Nuclear Information System (INIS)
Wasson, O.A.
1993-01-01
The objective of this interagency program is to provide accurate neutron interaction measurements for the US Department of Energy nuclear programs which include waste disposal, fusion, safeguards, defense, fission, and personnel protection. These measurements are also useful to other energy programs which indirectly use the unique properties of the neutron for diagnostic and analytical purposes. The work includes the measurement of reference cross sections and related neutron data employing unique facilities and capabilities at NIST and other laboratories as required; leadership and participation in international intercomparisons and collaborations; the preservation of standard reference deposits and the development of improved neutron detectors and measurement methods. A related and essential element of the program is critical evaluation of neutron interaction data including international coordinations. Data testing of critical data for important applications is included. The program is jointly supported by the Department of Energy and the National Institute of Standards and Technology. This report from the National Institute of Standards and Technology contains a summary of the accomplishments of the Neutron Cross Section Standards and Instrumentation Project during the third year of this three-year interagency agreement. The proposed program and required budget for the following three years are also presented. The program continues the shifts in priority instituted in order to broaden the program base
Kim, Haksung; Ho Pyeon, Cheol; Lim, Jae-Yong; Misawa, Tsuyoshi
2012-01-01
The effects of silicon cross section and neutron spectrum on the radial uniformity of a Si-ingot are examined experimentally with various neutron spectrum conditions. For the cross section effect, the numerical results using silicon single crystal cross section reveal good agreements with experiments within relative difference of 6%, whereas the discrepancy is approximately 20% in free-gas cross section. For the neutron spectrum effect, the radial uniformity in hard neutron spectrum is found to be more flattening than that in soft spectrum. Copyright © 2011 Elsevier Ltd. All rights reserved.
Sensitivity of neutron air transport to nitrogen cross section uncertainties
International Nuclear Information System (INIS)
Niiler, A.; Beverly, W.B.; Banks, N.E.
1975-01-01
The sensitivity of the transport of 14-MeV neutrons in sea level air to uncertainties in the ENDF/B-III values of the various Nitrogen cross sections has been calculated using the correlated sampling Monte Carlo neutron transport code SAMCEP. The source consisted of a 14.0- to 14.9-MeV band of isotropic neutrons and the fluences (0.5 to 15.0 MeV) were calculated at radii from 50 to 1500 metres. The maximum perturbations, assigned to the ENDF/B-III or base cross section set in the 6.0- to 14.5-MeV energy range were; (1) 2 percent to the total, (2) 10 percent to the total elastic, (3) 40 percent to the inelastic and absorption and (4) 20 percent to the first Legendre coefficient and 10 percent to the second Legendre coefficient of the elastic angular distribtuions. Transport calculations were carried out using various physically realistic sets of perturbed cross sections, bounded by evaluator-assigned uncertainties, as well as the base set. Results show that in some energy intervals at 1500 metres, the differential fluence level with a perturbed set differed by almost a factor of two from the differential fluence level with the base set. 5 figures
Summary of the Workshop on Neutron Cross Section Covariances
International Nuclear Information System (INIS)
Smith, Donald L.
2008-01-01
A Workshop on Neutron Cross Section Covariances was held from June 24-27, 2008, in Port Jefferson, New York. This Workshop was organized by the National Nuclear Data Center, Brookhaven National Laboratory, to provide a forum for reporting on the status of the growing field of neutron cross section covariances for applications and for discussing future directions of the work in this field. The Workshop focused on the following four major topical areas: covariance methodology, recent covariance evaluations, covariance applications, and user perspectives. Attention was given to the entire spectrum of neutron cross section covariance concerns ranging from light nuclei to the actinides, and from the thermal energy region to 20 MeV. The papers presented at this conference explored topics ranging from fundamental nuclear physics concerns to very specific applications in advanced reactor design and nuclear criticality safety. This paper provides a summary of this workshop. Brief comments on the highlights of each Workshop contribution are provided. In addition, a perspective on the achievements and shortcomings of the Workshop as well as on the future direction of research in this field is offered
Recent progress in fast neutron activation cross section data
International Nuclear Information System (INIS)
Michaelis, W.
A brief review is given of some significant investigations performed during the past few years in the area of fast neutron activation cross sections that may be relevant for the use of nuclear techniques in the exploration of mineral resources, in process and quality control in industry as well as for general analytical purposes. Differential capture cross sections are considered for the natural elements or isotopes of Fe, Cu, Se, Y, Nb, Cd, In, Gd, W, Os and Au. Some of the data are compared with statistical model calculations. Experimental and evaluated average cross sections for capture and threshold reactions in the spontaneous fission neutron field of 252 Cf are reviewed taking into account the elements or isotopes of Mg, Al, Si, S, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Sr, Zr, Nb, Cd, In, Ba, Ta and Au. A summary of recent studies of differential cross sections for threshold reactions comprises data on Al, Si, S, Ti, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ta, W and Au. Besides experimental investigations, evaluations and theoretical model calculations are considered. Cross sections at 14 MeV and in the region around this energy are reviewed for Na, Mg, Al, Cl, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Br, Sr, Zr, Nb, In, Er, Yb, Ta, W, Os, Ir, Au and Pb. Particular emphasis is laid on (n,p), (n,2n) and (n,α) reactions. (n,n') reactions are allowed for if the half-life of the metastable state excited permits elemental analyses by common experimental techniques. (orig.)
Summary report of technical meeting on neutron cross section covariances
International Nuclear Information System (INIS)
Trkov, A.; Smith, D.L.; Capote Noy, R.
2011-01-01
A summary is given of the Technical Meeting on Neutron Cross Section Covariances. The meeting goal was to assess covariance data needs and recommend appropriate methodologies to address those needs. Discussions on covariance data focused on three general topics: 1) Resonance and unresolved resonance regions; 2) Fast neutron region; and 3) Users' perspective: benchmarks' uncertainty and reactor dosimetry. A number of recommendations for further work were generated and the important work that remains to be done in the field of covariances was identified. (author)
Absolute measurements of neutron cross sections. Progress report
International Nuclear Information System (INIS)
1984-11-01
In the photoneutron laboratory, we have completed a major refurbishing of experimental facilities and begun work on measurements of the capture cross section in thorium and U-238. In the 14 MeV neutron experimental bay, work continues on the measurement of 14 MeV neutron induced reactions of interest as standards or because of their technological importance. First results have been obtained over the past year, and we are extending these measurements along the lines outlined in our proposal of a year ago
Calculation of neutron-induced single-event upset cross sections for semiconductor memory devices
International Nuclear Information System (INIS)
Ikeuchi, Taketo; Watanabe, Yukinobu; Nakashima, Hideki; Sun, Weili
2001-01-01
Neutron-induced single-event upset (SEU) cross sections for semiconductor memory devices are calculated by the Burst Generation Rate (BGR) method using LA150 data and QMD calculation in the neutron energy range between 20 MeV and 10 GeV. The calculated results are compared with the measured SEU cross sections for energies up to 160 MeV, and the validity of the calculation method and the nuclear data used is verified. The kind of reaction products and the neutron energy range that have the most effect on SEU are discussed. (author)
Generation of neutron scattering cross sections for silicon dioxide
International Nuclear Information System (INIS)
Ramos, R; Marquez Damian, J.I; Granada, J.R.; Cantargi, F
2009-01-01
A set of neutron scattering cross sections for silicon and oxygen bound in silicon dioxide were generated and validated. The cross sections were generated in the ACE format for MCNP using the nuclear data processing system NJOY, and the validation was done with published experimental data. This cross section library was applied to the calculation of five critical configurations published in the benchmark Critical Experiments with Heterogeneous Compositions of Highly Enriched Uranium, Silicon Dioxide and Polyethylene. The original calculations did not use the thermal scattering libraries generated in this work and presented significant differences with the experimental results. For this reason, the newly generated library was added to the input and the multiplication factor for each configuration was recomputed. The utilization of the thermal scattering libraries did not result in an improvement of the computational results. Based on this we conclude that integral experiments to validate this type of thermal cross sections need to be designed with a higher influence of thermal scattering in the measured result, and the experiments have to be performed under more controlled conditions. [es
Stellar neutron capture cross sections of the Ba isotopes
International Nuclear Information System (INIS)
Voss, F.; Wisshak, K.; Guber, K.; Kaeppeler, F.; Reffo, G.
1994-03-01
The neutron capture cross sections of 134 Ba, 135 Ba, 136 Ba, and 137 Ba were measured in the energy range from 5 to 225 keV at the Karlsruhe 3.75 MV Van de Graaff accelerator. Neutrons were produced via the 7 Li(p,n) 7 Be reaction by bombarding metallic Li targets with a pulsed proton beam. Capture events were registered with the Karlsruhe 4π Barium Fluoride Detector. Several runs have been performed under different experimental conditions to study the systematic uncertainties, which resulted mainly from the large ratios of total to capture cross sections of up to 400. The cross section ratios were determined with an overall uncertainty of ∼3%, an improvement by factors of five to eight compared to existing data. Severe discrepancies were found with respect to previous results. Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT=10 keV and 100 keV. These stellar cross sections were used in an s-process analysis. For the s-only isotopes 134 Ba and 136 Ba the N s ratio was determined to 0.875±0.025. Hence, a significant branching of the s-process path at 134 Cs can be claimed for the first time, in contrast to predictions from the classical approach. This branching yields information on the s-process temperature, indicating values around T 8 =2. The new cross sections are also important for the interpretation of barium isotopic anomalies, which were recently discovered in SiC grains of carbonaceous chondrite meteorites. Together with the results from previous experiments on tellurium and samarium, a general improvement of the N s systematics in the mass range A=120 to 150 is achieved. This allows for a more reliable separation of s- and r-process yields, resulting in an improved assignment of the respective contributions to elemental barium that is required for comparison with stellar observations. (orig.) [de
Cross-section calculations for neutron-induced reactions up to 50 MeV
International Nuclear Information System (INIS)
Yamamuro, Nobuhiro.
1996-01-01
In the field of accelerator development, medium-energy reaction cross-section data for structural materials of accelerator and shielding components are required, especially for radiation protection purposes. For a d + Li stripping reaction neutron source used in materials research, neutron reaction cross sections up to 50 MeV are necessary for the design study of neutron irradiation facilities. The current version of SINCROS-II is able to calculate neutron and proton-induced reaction cross sections up to ∼ 50 MeV with some modifications and extensions of the cross-section calculation code. The production of isotopes when structural materials and other materials are bombarded with neutrons or protons is calculated using a revised code in the SINCROS-II system. The parameters used in the cross-section calculations are mainly examined with proton-induced reactions because the experimental data for neutrons above 20 MeV are rare. The status of medium mass nuclide evaluations for aluminum, silicon, chromium, manganese, and copper is presented. These data are useful to estimate the radiation and transmutation of nuclei in the materials
Measurements of neutron capture cross sections of wolfram and thulium
International Nuclear Information System (INIS)
Xia Yijun; Wang Chunhao; Yang Jingfu; Yang Zhihua; Luo Xiaobing
1992-01-01
The neutron capture cross sections of wolfram and thulium were measured in the energy range from 10 to 100 KeV using gold as the standard. Kinematically collimated neutrons were produced via the 7 Li(p, n) 7 Be reaction with a 2.5 MV pulsed Van de Graaff accelerator at Sichuan University. The capture events were detected by a pair of Moxon-Rae detectors. Time-of-flight technique was used to improve the signal-background ratio. The present results are compared with data by other authors. The capture cross section were calculated from 10 to 100 KeV for two nuclides by the Hauser-Feshbach statistical theory with width fluctuation correction. The nonstatistical effects such as potential capture and radiative capture in elastic and inelastic channels of a compound nucleus were included in the calculations. The calculated results show that the nonstatistical contribution to the capture cross sections is negligible compared with that of the statistical effects
Neutron capture cross section standards for BNL-325
International Nuclear Information System (INIS)
Holden, N.E.
1980-01-01
The most common cross section standards for capture reactions in the thermal neutron energy region are gold, cobalt, and manganese. In preparation for the fourth edition of BNL-325, data on the thermal cross section and resonance integral were evaluated for these three standards. For gold, only measurements below the Bragg scattering cutoff were used and extrapolated to a neutron velocity of 2200 meters/second. A non 1/v correction due to the 4.9 eV resonance was made. The resonance integral is based on Jirlow's integral measurement and Tellier's parameters. The resonance integrals for cobalt and manganese are based solely on integral measurements because the capture widths of the first major resonance either vary by 20% in various measurements (cobalt), or have never been measured (manganese). Recommended thermal cross sections and resonance integrals are respectively gold: 98.65/plus or minus/0.9 barns, 1550/plus or minus/28 barns; cobalt: 37.18/plus or minus/0.06 barns, 74.2/plus or minus/2.0 barns and manganese: 13.3/plus or minus/0.2 barns, and 14.0/plus or minus/0.3 barns. 72 refs
Evaluation of cross sections for neutron-induced reactions in sodium
International Nuclear Information System (INIS)
Larson, D.C.
1980-09-01
An evaluation of the neutron-induced cross sections of 23 Na has been done for the energy range from 10 -5 eV to 20 MeV. All significant cross sections are given, including differential cross sections for production of gamma rays. The recommended values are based on experimental data where available, and use results of a consistent model code analysis of available data to predict cross sections where there are no experimental data. This report describes the evaluation that was submitted to the Cross Section Evaluation Working Group (CSEWG) for consideration as a part of the Evaluated Nuclear Data File, Version V, and subsequently issued as MAT 1311. 126 references, 130 figures, 14 tables
Influence of cross-section structure on unfolded neutron spectra
International Nuclear Information System (INIS)
Ertek, C.; Vlasov, M.F.; Cross, B.; Smith, P.M.
1979-01-01
The influence of cross-section structure on neutron spectra unfolded by multiple foil activation technique, SAND-II case, has been studied. For three reactions with evident structure in neutron cross-section above threshold: 27Al(n,α)24Na, 31P(n,p)31Si and 32S(n,p)32P, two remarkably different sets of evaluated data were selected from the available evaluations; one set of data was ''smooth'', the structure having been averaged over by a smooth curve; the other set was ''sharp'' with structure given in detail. These data were used in unfolding procedure together with other reactions, the same in both cases (as well as input spectra and measured reaction rates). It was found that during unfolding calculations less iteration steps were needed to unfold the neutron flux spectrum with the set of ''sharp'' data. In case of ''smooth'' data it was difficult to obtain an agreement between measured and calculated activity values even by increasing the number of iteration steps. Contrary to expectations, considerable deformation of unfolded neutron flux spectrum has been observed in the case of the ''smooth'' data set. (author)
Neutron displacement damage cross sections for SiC
International Nuclear Information System (INIS)
Huang Hanchen; Ghoniem, N.
1993-01-01
Calculations of neutron displacement damage cross sections for SiC are presented. We use Biersack and Haggmark's empirical formula in constructing the electronic stopping power, which combines Lindhard's model at low PKA energies and Bethe-Bloch's model at high PKA energies. The electronic stopping power for polyatomic materials is computed on the basis of Bragg's Additivity Rule. A continuous form of the inverse power law potential is used for nuclear scattering. Coupled integro-differential equations for the number of displaced atoms j, caused by PKA i, are then derived. The procedure outlined above gives partial displacement cross sections, displacement cross sections for each specie of the lattice, and for each PKA type. The corresponding damage rates for several fusion and fission neutron spectra are calculated. The stoichiometry of the irradiated material is investigated by finding the ratio of displacements among various atomic species. The role of each specie in displacing atoms is also investigated by calculating the fraction of displacements caused by each PKA type. The study shows that neutron displacement damage rates of SiC in typical magnetic fusion reactor first walls will be ∝10-15 dpa MW -1 m 2 ; in typical lead-protected inertial confinement fusion reactor first walls they will be ∝15-20 dpa MW -1 m 2 . For fission spectra, we find that the neutron displacement damage rate of SiC is ∝74 dpa per 10 27 n/m 2 in FFTF, ∝39 dpa per 10 27 n/m 2 in HFIR, and 25 dpa per 10 27 n/m 2 in NRU. Approximately 80% of displacement atoms are shown to be of the carbon-type. (orig.)
Neutron cross sections for the interpretation of a spallation experiment
International Nuclear Information System (INIS)
Bortignon, P.F.; Mariani, F.; Perini, A.; Sangiust, V.
1994-01-01
An irradiation was carried out in a spallation neutron spectrum at the beam stop of LAMPF (Los Alamos); many activation detectors were used in order to obtain a fluence mapping inside the capsule volume. The cross sections were derived from ENDF B/V Dosimetry File up to 20 MeV and were based on calculations with the code ALICE up to 200 MeV. From 200 to 800 MeV an empirical extrapolation was employed since no data, calculated or measured, were available at the moment. An attempt has been made in this paper to revisit the interpretation of the experiment reconsidering the cross sections in the energy range from 200 to 800 MeV as given by the semiempirical models of Rudstam, Silberger and Tsao and Hufner
Evaluation of 28,29,30Si neutron induced cross sections for ENDF/B-VI
International Nuclear Information System (INIS)
Hetrick, D.M.; Larson, D.C.; Larson, N.M.; Leal, L.C.; Epperson, S.J.
1997-04-01
Separate evaluations have been done for the three stable isotopes of silicon for ENDF/B-VI. The evaluations are based on analysis of experimental data, supplemented by results of nuclear model calculations. The computational methods and the parameters required as input to the nuclear model codes are reviewed. Discussion of the evaluated data given for resonance parameters, neutron induced reaction cross sections, associated angular and energy distributions, and gamma-ray production cross sections is included. Extensive comparisons of the evaluated cross sections to measured data are shown in this report. The evaluations include all necessary data to allow KERMA (Kinetic Energy Released in MAterials) and displacement cross sections to be calculated directly. These quantities are fundamental to studies of neutron heating and radiation damage
Amino acids analysis by total neutron cross-sections determinations: part V
International Nuclear Information System (INIS)
Voi, Dante L.; Ferreira, Francisco de O.; Rocha, Helio F. da
2013-01-01
Total neutron cross-sections of twenty essential and non-essential amino acids to human were determined using crystal spectrometer installed on the Argonauta reactor of IEN (Instituto de Engenharia Nuclear (CNEN-RJ) and compared with data generated by parceling and grouping methodologies developed at this institution. For each amino acid was calculated the respective neutron cross-section by molecular structure, conformation and chemistry analysis. The results obtained for eighteen of twenty amino acids confirm the specifications and product formulations indicated by manufactures. These initial results allow to build a neutron cross-sections database as part of quality control of the amino supplied to hospitals for production of nutriments for parenteral or enteral formulations used in critical patients dependent on artificial feed, and for application in future studies of structure and dynamics for more complex molecules, including proteins, enzymes, fatty acids, membranes, organelles and other cell components. (author)
International Nuclear Information System (INIS)
Sanami, T.; Hagiwara, M.; Oishi, T.; Hosokawa, M.; Kamada, S.; Tanaka, Su.; Iwamoto, Y.; Nakashima, H.; Baba, M.
2009-01-01
A Bragg curve counter equipped with an internal production target was developed for the measurements of double-differential cross-sections of fragment production induced by neutrons at energies of tens of MeV. The internal target permitted a large detection solid angle and thus the registration of processes at low production rates. In this specific geometry, the detection solid angle depends on the emission angle and the range of the particle. Therefore the energy, atomic number, and angle of trajectory of the particle have to be taken into account for the determination of the solid angle. For the selection of events with tracks confined within a defined cylindrical volume around the detector axis, a segmented anode was applied. The double-differential cross-sections for neutron-induced production of lithium, beryllium, and boron fragments from a carbon target were measured at 0 deg. for 65 MeV neutrons. The results are in good agreement with theoretical calculation using PHITS code with GEM and ISOBAR model.
Energy Technology Data Exchange (ETDEWEB)
Garg, K C; Khurana, C S [Punjabi Univ., Patiala (India). Dept. of Physics
1979-01-01
The automatic electronic programmer developed to handle the millisecond isomers has been utilized to measure the reaction cross-sections for the production of /sup 6/He from sup(7,6)Li((n,d)+(n,p))/sup 6/He and /sup 9/Be(n,..cap alpha..)/sup 6/He reactions and /sup 9/Li from /sup 9/Be(n,p)/sup 9/Li reaction. An on-line gated G.M. counter has been used to follow the decay curves of beta-activities of /sup 6/He(805 ms.) and /sup 9/Li(175 ms.) produced in the reactions. Values of measured cross sections are 10.4 +- 1.0 mb., 10.6 +- 1.1 mb. and 40.3 +- 4.0 mb respectively for the above the three reactions.
Neutron cross section standards evaluations for ENDF/B-VI
International Nuclear Information System (INIS)
Carlson, A.D.; Poenitz, W.P.; Hale, G.M.; Peelle, R.W.
1985-01-01
The neutron cross section standards are now being evaluated as the initial phase in the development of the new ENDF/B-VI file. These standards evaluations are following a somewhat different process compared with that used for earlier versions of ENDF. The primary effort is concentrated on a simultaneous evaluation using a generalized least squares program, R-matrix evaluations, and a procedure for combining the results of these evaluations. The ENDF/B-VI standards evaluation procedure is outlined, and preliminary simultaneous evaluation and R-matrix results are presented. 16 refs., 7 figs
Neutron-induced cross-sections via the surrogate method
International Nuclear Information System (INIS)
Boutoux, G.
2011-11-01
The surrogate reaction method is an indirect way of determining neutron-induced cross sections through transfer or inelastic scattering reactions. This method presents the advantage that in some cases the target material is stable or less radioactive than the material required for a neutron-induced measurement. The method is based on the hypothesis that the excited nucleus is a compound nucleus whose decay depends essentially on its excitation energy and on the spin and parity state of the populated compound state. Nevertheless, the spin and parity population differences between the compound-nuclei produced in the neutron and transfer-induced reactions may be different. This work reviews the surrogate method and its validity. Neutron-induced fission cross sections obtained with the surrogate method are in general good agreement. However, it is not yet clear to what extent the surrogate method can be applied to infer radiative capture cross sections. We performed an experiment to determine the gamma decay probabilities for 176 Lu and 173 Yb by using the surrogate reactions 174 Yb( 3 He,pγ) 176 Lu * and 174 Yb( 3 He,αγ) 173 Yb * , respectively, and compare them with the well-known corresponding probabilities obtained in the 175 Lu(n,γ) and 172 Yb(n,γ) reactions. This experiment provides answers to understand why, in the case of gamma-decay, the surrogate method gives significant deviations compared to the corresponding neutron-induced reaction. In this work, we have also assessed whether the surrogate method can be applied to extract capture probabilities in the actinide region. Previous experiments on fission have also been reinterpreted. Thus, this work provides new insights into the surrogate method. This work is organised in the following way: in chapter 1, the theoretical aspects related to the surrogate method will be introduced. The validity of the surrogate method will be investigated by means of statistical model calculations. In chapter 2, a review on
A compact fast-neutron producing target for high resolution cross section measurements
Flaska, M.
2006-01-01
A proper knowledge of neutron cross sections is very important for the operation safety of various nuclear facilities. Reducing uncertainties in the neutron cross sections can lead to an enhanced safety of present and future nuclear power systems. Accurate neutron cross sections also play a relevant
Optical model calculation of neutron-nucleus scattering cross sections
International Nuclear Information System (INIS)
Smith, M.E.; Camarda, H.S.
1980-01-01
A program to calculate the total, elastic, reaction, and differential cross section of a neutron interacting with a nucleus is described. The interaction between the neutron and the nucleus is represented by a spherically symmetric complex potential that includes spin-orbit coupling. This optical model problem is solved numerically, and is treated with the partial-wave formalism of scattering theory. The necessary scattering theory required to solve this problem is briefly stated. Then, the numerical methods used to integrate the Schroedinger equation, calculate derivatives, etc., are described, and the results of various programming tests performed are presented. Finally, the program is discussed from a user's point of view, and it is pointed out how and where the program (OPTICAL) can be changed to satisfy particular needs
Differences between cross-section libraries for neutron dosimetry
International Nuclear Information System (INIS)
Tardelli, T.C.; Stecher, L.C.; Coelho, T.S.; Castro, V.A. De; Cavalieri, T.A.; Menzel, F.; Giarola, R.S.; Domingos, D.B.; Yoriyaz, H.
2013-01-01
Absorbed dose calculations depend on a consistent set of nuclear data used in simulations in computer codes. Nuclear data are stored in libraries, however, the information available about the differences in dose caused by different libraries are rare. The libraries are processed by a computer system to be able to be used by a radiation transport code. One of the systems capable of processing nuclear data is the NJOY system. The objective of this study is to evaluate the nuclear data libraries for neutrons available in the literature, and to quantify the differences in absorbed dose obtained using the libraries JENDL 4.0, JEFF 3.3.1 and ENDF/B.VII. The absorbed dose calculation was performed on a simple geometric model, as spheres, and in anthropomorphic model of the human body based on the ICRP-110 for neutron transport simulation using the MCNP5 code. The results were compared with literature data. The results obtained with cross sections from the libraries JEFF and ENDF/B.VII have shown to be identical in most cases, except for one case where the difference has exceeded 10%. The results obtained with JENDL library has shown to be considerably different in most cases comparing to other two libraries. Some differences were over 200%. The dose calculations showed differences between the libraries, which is justified by differences in the cross sections. It has been observed that the cross sections values of certain nuclides assume quite different values in different libraries. These differences in turn cause considerable differences in dose calculations. (author)
Research on Fast-Doppler-Broadening of neutron cross sections
International Nuclear Information System (INIS)
Li, S.; Wang, K.; Yu, G.
2012-01-01
A Fast-Doppler-Broadening method is developed in this work to broaden Continuous Energy neutron cross-sections for Monte Carlo calculations. Gauss integration algorithm and parallel computing are implemented in this method, which is unprecedented in the history of cross section processing. Compared to the traditional code (NJOY, SIGMA1, etc.), the new Fast-Doppler-Broadening method shows a remarkable speedup with keeping accuracy. The purpose of using Gauss integration is to avoid complex derivation of traditional broadening formula and heavy load of computing complementary error function that slows down the Doppler broadening process. The OpenMP environment is utilized in parallel computing which can take full advantage of modern multi-processor computers. Combination of the two can reduce processing time of main actinides (such as 238 U, 235 U) to an order of magnitude of 1∼2 seconds. This new method is fast enough to be applied to Online Doppler broadening. It can be combined or coupled with Monte Carlo transport code to solve temperature dependent problems and neutronics-thermal hydraulics coupled scheme which is a big challenge for the conventional NJOY-MCNP system. Examples are shown to determine the efficiency and relative errors compared with the NJOY results. A Godiva Benchmark is also used in order to test the ACE libraries produced by the new method. (authors)
International Nuclear Information System (INIS)
Kim, Haksung; Ho Pyeon, Cheol; Lim, Jae-Yong; Misawa, Tsuyoshi
2012-01-01
The effects of silicon cross section and neutron spectrum on the radial uniformity of a Si-ingot are examined experimentally with various neutron spectrum conditions. For the cross section effect, the numerical results using silicon single crystal cross section reveal good agreements with experiments within relative difference of 6%, whereas the discrepancy is approximately 20% in free-gas cross section. For the neutron spectrum effect, the radial uniformity in hard neutron spectrum is found to be more flattening than that in soft spectrum. - Highlights: ► The effects of silicon cross section and neutron spectrum on the radial uniformity in NTD were experimentally investigated. ► The numerical results using silicon single crystal cross section reveal good agreements. ► The radial uniformity in hard neutron spectrum was more flat than that in soft spectrum. ► The silicon single crystal cross section and hard neutron spectrum are recommended for numerical analyses and radial uniformity flattening in NTD, respectively.
Measurement of reaction cross sections of {sup 129}I induced by DT neutrons
Energy Technology Data Exchange (ETDEWEB)
Nakano, Daisuke; Murata, Isao; Takahashi, Akito [Osaka Univ., Suita (Japan). Faculty of Engineering
1997-03-01
The cross sections were measured for the {sup 129}I(n,2n){sup 128}I and {sup 129}I(n,{gamma}){sup 130}I reactions by DT neutrons, at OKTAVIAN facility of Osaka University, Japan. The foil activation method was used in the measurement. The sample was a sealed source of {sup 129}I, which was covered with a Cd foil. The irradiations were performed for 75 minutes to obtain the cross section of reaction producing {sup 128}I (T{sub 1/2}=24.99m) and 22 hours for the {sup 130}I (T{sub 1/2}=12.36h), respectively. The gamma-rays emitted from the irradiated sample were measured with a high purity Ge detector. The measured cross sections of {sup 129}I(n,2n){sup 128}I and {sup 129}I(n,{gamma}){sup 130}I reactions were 0.92{+-}0.11 barn and 0.013{+-}0.002 barn, respectively. For the {sup 129}I(n,2n){sup 128}I reaction, the evaluation of JENDL-3.2 overestimates cross section about 60% to the experimental result. However, especially for the {sup 129}I(n,{gamma}) reaction, the measured cross section may include the contribution from the neutrons in MeV region as well as epithermal ones. Also, the obtained cross section of the {sup 129}I(n,{gamma}){sup 130}I reaction was evaluated as an effective production cross section of {sup 130}I including {sup 129}I(n,{gamma}){sup 130m}I reaction. In order to remove the contribution from the epithermal and MeV region neutrons. A new method was proposed for the measurement of (n,{gamma}) reaction cross section. (author)
Neutron cross section measurement using the Oak Ridge Electron Linear Accelerator
International Nuclear Information System (INIS)
Winters, R.R.
1991-08-01
This report discusses: argon-40 -- neutron reaction total cross sections from 6.9 kev to 50 kev; The maxwellian averaged neutron capture cross section of oxygen-16; r-matrix parameter analysis of the lead-208 -- neutron reaction cross section measurement; r-matrix parameter analysis of the ORELA neutron transmission zirconium-90 low energy measurement; porting computer codes from the HP9000 to the IBM RISC/6000;and measurements of neutron reactions with strontium-88, zirconium-90, and calcium-40
International Nuclear Information System (INIS)
Ku, L.P.; Price, W.G. Jr.
1977-08-01
The neutronic calculation for the Livermore mirror fusion/fission hybrid reactor blanket was performed using the PPPL cross section library. Significant differences were found in the tritium breeding and plutonium production in comparison to the results of the LLL calculation. The cross section sensitivity study for tritium breeding indicates that the response is sensitive to the cross section of 238 U in the neighborhood of 14 MeV and 1 MeV. The response is also sensitive to the cross sections of iron in the vicinity of 14 MeV near the first wall. Neutron transport in the resonance region is not important in this reactor model
Inelastic neutron scattering cross-section measurements on 7Li and 63,65Cu
Nyman, Markus; Belloni, Francesca; Ichinkhorloo, Dagvadorj; Pirovano, Elisa; Plompen, Arjan; Rouki, Chariklia
2017-09-01
The γ-ray production cross section for the 477.6-keV transition in 7Li following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other inelastic scattering measurements. The experiment was conducted at the Geel Electron LINear Accelerator (GELINA) pulsed white neutron source with the Gamma Array for Inelastic Neutron Scattering (GAINS) spectrometer. Previous measurements of this cross section are reviewed and compared with our results. Recently, this cross section has also been calculated using the continuum discretized coupled-channels (CDCC) method. Experiments for studying neutrinoless double-β decay (2β0ν) or other very rare processes require greatly reducing the background radiation level (both intrinsic and external). Copper is a common shielding and structural material, used extensively in experiments such as COBRA, CUORE, EXO, GERDA, and MAJORANA. Understanding the background contribution arising from neutron interactions in Cu is important when searching for very weak experimental signals. Neutron inelastic scattering on natCu was investigated with GAINS. The results are compared with previous experimental data and evaluated nuclear data libraries.
Inelastic neutron scattering cross-section measurements on 7Li and 63,65Cu
Directory of Open Access Journals (Sweden)
Nyman Markus
2017-01-01
Full Text Available The γ-ray production cross section for the 477.6-keV transition in 7Li following inelastic neutron scattering has been measured from the reaction threshold up to 18 MeV. This cross section is interesting as a possible standard for other inelastic scattering measurements. The experiment was conducted at the Geel Electron LINear Accelerator (GELINA pulsed white neutron source with the Gamma Array for Inelastic Neutron Scattering (GAINS spectrometer. Previous measurements of this cross section are reviewed and compared with our results. Recently, this cross section has also been calculated using the continuum discretized coupled-channels (CDCC method. Experiments for studying neutrinoless double-β decay (2β0ν or other very rare processes require greatly reducing the background radiation level (both intrinsic and external. Copper is a common shielding and structural material, used extensively in experiments such as COBRA, CUORE, EXO, GERDA, and MAJORANA. Understanding the background contribution arising from neutron interactions in Cu is important when searching for very weak experimental signals. Neutron inelastic scattering on natCu was investigated with GAINS. The results are compared with previous experimental data and evaluated nuclear data libraries.
Neutron cross sections in the unresolved resonance region
International Nuclear Information System (INIS)
Janeva, N.; Lukyanov, A.; Koyumdjieva, N.; Volev, K.
2005-01-01
In this work a development of the characteristic function model, created to reveal the resonance cross section structure in the unresolved resonance region is presented. The main advantage of this model is the calculation of resonance averaged self-shielding factors analytically. To determine average values of the cross sections and their functionals the function of joint statistical distribution of the R-matrix real and imaginary parts should be used. The characteristic function of such distribution is determined and the resonance ladder for the unresolved region is optimized to calculate the group averaged functionals in the same way as it is in the resolved resonance region. The main advantage of this model is the calculation of resonance averaged self-shielding factors analytically. The neutron width energy dependence leads to some deformation in the shape of resonances. This deformation is most apparent near the inelastic scattering threshold. For the case when the inelastic channel momentum is zero we present the formula for level shape bellow and over the inelastic threshold and the calculated resonance deformation in dependence of the position of the resonance in respect to the threshold. (authors)
International Nuclear Information System (INIS)
Belgya, T.
2006-01-01
A complete elemental gamma-ray library was measured with our guided thermal beam at the Budapest PGAA facility in the period of 1995-2000. Using this data library in an IAEA CRP on PGAA it was managed to re-normalize the ENSDF intensity data with the Budapest intensities. Based on this renormalization thermal neutron cross sections were deduced for several isotopes. Most of these calculations were done by Richard B. Firestone. The Budapest PGAA-NIPS facilities have been used for routine prompt gamma activation analysis with cold neutrons since the year of 2000. The advantage of the cold neutron beam is that the neutron guide has much higher neutron transmission. This resulted in a gain factor about 20 relative to our thermal guide. For the analytical works a precise comparator technique was developed that is routinely used to determine partial gamma-ray production cross sections. An additional development of our methodology was necessary to be worked out to determine thermal neutron capture cross sections based on the partial gamma-ray production cross sections. In this talk our methodology of radiative capture cross section determination will be presented, including our latest results on 129 I, 204,206,207 Pb and 209 Bi. Most of these works were done in cooperation with people from EU-JRC-IRMM, Geel, Belgium and CEA Cadarache, France. Many partial cross sections of short lived nuclei have been re-measured with our new chopper technique. The uncertainty calculations of the radiative capture cross section determination procedures will be also shown. (authors)
Effective thermal neutron absorption cross section for heterogeneous mixture
International Nuclear Information System (INIS)
Gabanska, B.; Igielski, A.; Krynicka-Drozdowicz, E.; Woznicka, U.
1989-01-01
The first estimations (basing on Umiastowski's theory) of the influence of the sample heterogeneity of the effective thermal neutron absorption cross section were compared with the results obtained for the homogeneous mixture which components and concentration were the same as those of the heterogeneous sample. An experiment was prepared to determine how good this estimate is. Three artificial heterogeneous cylindrical samples (2R = H = 9 cm) were manufactured from pure silver cylinders embedded in plexiglass, keeping the Ag content and varying the size of cylinders (2R = H = 1.0 cm, 0.6 cm and 0.4 cm). Calculations performed show that the experimental effect of the sample heterogeneity can be significant. 5 figs., 5 tabs, 11 refs. (author)
pp production cross sections and the constraint method
International Nuclear Information System (INIS)
Anjos, J.C.; Santoro, A.F.S.; Souza, M.H.G.
1983-01-01
A method of constructing production cross sections that satisfy the constraints represented by the first few moments is shown to give an excellent account of the data when applied to the high energy pp production cross section ν sub(n) (s) plotted as functions of n. (Author) [pt
Measurement of dijet cross sections for events with a leading neutron in photoproduction at HERA
International Nuclear Information System (INIS)
Breitweg, J.; Chekanov, S.; Derrick, M.; Krakauer, D.; Magill, S.; Musgrave, B.; Pellegrino, A.; Repond, J.; Stanek, R.; Yoshida, R.; Mattingly, M.C.K.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Giusti, P.; Iacobucci, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Palmonari, F.; Pesci, A.; Sartorelli, G.; Zichichi, A.; Amelung, C.; Bornheim, A.; Brock, I.; Coboeken, K.; Crittenden, J.; Deffner, R.; Hartmann, H.; Heinloth, K.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Kappes, A.; Katz, U.F.; Kerger, R.; Paul, E.; Rautenberg, J.; Schnurbusch, H.; Stifutkin, A.; Tandler, J.; Voss, K.C.; Weber, A.; Wieber, H.; Bailey, D.S.; Barret, O.; Brook, N.H.; Foster, B.; Heath, G.P.; Heath, H.F.; Rodrigues, E.; Scott, J.; Tapper, R.J.; Capua, M.; Schioppa, M.; Susinno, G.; Jeoung, H.Y.; Kim, J.Y.; Lee, J.H.; Lim, I.T.; Ma, K.J.; Pac, M.Y.; Caldwell, A.; Liu, W.; Liu, X.; Mellado, B.; Paganis, S.; Sampson, S.; Schmidke, W.B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Klimek, K.; Olkiewicz, K.; Piotrzkowski, K.; Przybycien, M.B.; Stopa, P.; Zawiejski, L.; Bednarek, B.; Jelen, K.; Kisielewska, D.; Kowal, A.M.; Kowalski, T.; Przybycien, M.; Rulikowska-Zarebska, E.; Suszycki, L.; Szuba, D.; Kotanski, A.; Bauerdick, L.A.T.; Behrens, U.; Bienlein, J.K.; Borras, K.; Chiochia, V.; Dannheim, D.; Desler, K.; Drews, G.; Fox-Murphy, A.; Fricke, U.; Goebel, F.; Goers, S.; Goettlicher, P.; Graciani, R.; Haas, T.; Hain, W.; Hartner, G.F.; Hebbel, K.; Hillert, S.; Koch, W.; Koetz, U.; Kowalski, H.; Labes, H.; Loehr, B.; Mankel, R.; Martens, J.; Martinez, M.; Milite, M.; Moritz, M.; Notz, D.; Petrucci, M.C.; Polini, A.; Rohde, M.; Savin, A.A.; Schneekloth, U.; Selonke, F.; Sievers, M.; Stonjek, S.; Wolf, G.; Wollmer, U.; Youngman, C.; Zeuner, W.; Coldewey, C.; Lopez-Duran Viani, A.; Meyer, A.; Schlenstedt, S.; Straub, P.B.; Barbagli, G.; Gallo, E.; Parenti, A.; Pelfer, P.G.; Bamberger, A.; Benen, A.; Coppola, N.; Eisenhardt, S.; Markun, P.; Raach, H.; Woelfle, S.; Bussey, P.J.; Bell, M.; Doyle, A.T.; Glasman, C.; Lee, S.W.; Lupi, A.; Macdonald, N.; McCance, G.J.; Saxon, D.H.; Sinclair, L.E.; Skillicorn, I.O.; Waugh, R.; Bohnet, I.; Gendner, N.; Holm, U.; Meyer-Larsen, A.; Salehi, H.; Wick, K.; Carli, T.; Garfagnini, A.; Gialas, I.; Gladilin, L.K.; Kcira, D.; Klanner, R.; Lohrmann, E.; Goncalo, R.; Long, K.R.; Miller, D.B.; Tapper, A.D.; Walker, R.; Cloth, P.; Filges, D.; Ishii, T.; Kuze, M.; Nagano, K.; Tokushuku, K.; Yamada, S.; Yamazaki, Y.; Ahn, S.H.; Lee, S.B.; Park, S.K.; Lim, H.; Son, D.; Barreiro, F.; Garcia, G.; Gonzalez, O.; Labarga, L.; del Peso, J.; Redondo, I.; Terron, J.; Vazquez, M.; Barbi, M.; Corriveau, F.; Hanna, D.S.; Ochs, A.; Padhi, S.; Stairs, D.G.; Wing, M.; Tsurugai, T.; Antonov, A.; Bashkirov, V.; Danilov, M.; Dolgoshein, B.A.; Gladkov, D.; Sosnovtsev, V.; Suchkov, S.; Dementiev, R.K.; Ermolov, P.F.; Golubkov, Yu.A.; Katkov, I.I.; Khein, L.A.; Korotkova, N.A.; Korzhavina, I.A.; Kuzmin, V.A.; Lukina, O.Yu.; Proskuryakov, A.S.; Shcheglova, L.M.; Solomin, A.N.; Vlasov, N.N.; Zotkin, S.A.; Bokel, C.; Botje, M.; Bruemmer, N.; Engelen, J.; Grijpink, S.; Koffeman, E.; Kooijman, P.; Schagen, S.; van Sighem, A.; Tassi, E.; Tiecke, H.; Tuning, N.; Velthuis, J.J.; Vossebeld, J.; Wiggers, L.; de Wolf, E.; Bylsma, B.; Durkin, L.S.; Gilmore, J.; Ginsburg, C.M.; Kim, C.L.; Ling, T.Y.; Boogert, S.; Cooper-Sarkar, A.M.; Devenish, R.C.E.; Grosse-Knetter, J.; Matsushita, T.; Ruske, O.; Sutton, M.R.; Walczak, R.; Bertolin, A.; Brugnera, R.; Carlin, R.; Dal Corso, F.; Dusini, S.; Limentani, S.; Longhin, A.; Posocco, M.; Stanco, L.; Turcato, M.; Adamczyk, L.; Iannotti, L.; Oh, B.Y.; Okrasinski, J.R.; Saull, P.R.B.; Toothacker, W.S.; Whitmore, J.J.; Iga, Y.; D'Agostini, G.; Marini, G.; Nigro, A.; Cormack, C.; Hart, J.C.; McCubbin, N.A.; Shah, T.P.; Epperson, D.; Heusch, C.; Sadrozinski, H.F.-W.; Seiden, A.; Wichmann, R.; Williams, D.C.; Park, I.H.; Pavel, N.; Abramowicz , H.; Dagan, S.; Kananov, S.; Kreisel, A.; Levy, A.; Abe, T.; Fusayasu, T.; Kohno, T.; Umemori, K.; Yamashita, T.; Hamatsu, R.; Hirose, T.; Inuzuka, M.; Kitamura, S.; Matsuzawa, K.; Nishimura, T.; Arneodo, M.; Cartiglia, N.; Cirio, R.; Costa, M.; Ferrero, M.I.; Maselli, S.; Monaco, V.; Peroni, C.; Ruspa, M.; Sacchi, R.; Solano, A.; Staiano, A.; Bailey, D.C.; Fagerstroem, C.-P.; Galea, R.; Koop, T.; Levman, G.M.; Martin, J.F.; Mirea, A.; Sabetfakhri, A.; Butterworth, J.M.; Hayes, M.E.; Heaphy, E.A.; Jones, T.W.; Lane, J.B.; West, B.J.; Ciborowski, J.; Ciesielski, R.; Grzelak, G.; Nowak, R.J.; Pawlak, J.M.; Pawlak, R.; Smalska, B.; Tymieniecka, T.; Wroblewski, A.K.; Zakrzewski, J.A.; Zarnecki, A.F.; Adamus, M.; Gadaj, T.; Deppe, O.; Eisenberg, Y.; Hochman, D.; Karshon, U.; Badgett, W.F.; Chapin, D.; Cross, R.; Foudas, C.; Mattingly, S.; Reeder, D.D.; Smith, W.H.; Vaiciulis, A.; Wildschek, T.; Wodarczyk, M.; Deshpande, A.; Dhawan, S.; Hughes, V.W.; Bhadra, S.; Catterall, C.; Cole, J.E.; Frisken, W.R.; Hall-Wilton, R.; Khakzad, M.; Menary, S.
2001-01-01
Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e + +p→e + +n+jet+jet+X r have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb -1 . The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies E T jet >6 GeV, neutron energy E n >400 GeV, and neutron production angle θ n <0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model
Measurement of dijet cross sections for events with a leading neutron in photoproduction at HERA
Energy Technology Data Exchange (ETDEWEB)
Breitweg, J.; Chekanov, S.; Derrick, M.; Krakauer, D.; Magill, S.; Musgrave, B.; Pellegrino, A.; Repond, J.; Stanek, R.; Yoshida, R.; Mattingly, M.C.K.; Antonioli, P.; Bari, G.; Basile, M.; Bellagamba, L.; Boscherini, D.; Bruni, A.; Bruni, G.; Cara Romeo, G.; Cifarelli, L.; Cindolo, F.; Contin, A.; Corradi, M.; De Pasquale, S.; Giusti, P.; Iacobucci, G.; Levi, G.; Margotti, A.; Massam, T.; Nania, R.; Palmonari, F.; Pesci, A.; Sartorelli, G.; Zichichi, A.; Amelung, C.; Bornheim, A.; Brock, I.; Coboeken, K.; Crittenden, J.; Deffner, R.; Hartmann, H.; Heinloth, K.; Hilger, E.; Irrgang, P.; Jakob, H.-P.; Kappes, A.; Katz, U.F.; Kerger, R.; Paul, E.; Rautenberg, J.; Schnurbusch, H.; Stifutkin, A.; Tandler, J.; Voss, K.C.; Weber, A.; Wieber, H.; Bailey, D.S.; Barret, O.; Brook, N.H.; Foster, B. E-mail: b.foster@bristol.ac.uk; Heath, G.P.; Heath, H.F.; Rodrigues, E.; Scott, J.; Tapper, R.J.; Capua, M.; Schioppa, M.; Susinno, G.; Jeoung, H.Y.; Kim, J.Y.; Lee, J.H.; Lim, I.T.; Ma, K.J.; Pac, M.Y.; Caldwell, A.; Liu, W.; Liu, X.; Mellado, B.; Paganis, S.; Sampson, S.; Schmidke, W.B.; Sciulli, F.; Chwastowski, J.; Eskreys, A.; Figiel, J.; Klimek, K.; Olkiewicz, K.; Piotrzkowski, K.; Przybycien, M.B.; Stopa, P.; Zawiejski, L.; Bednarek, B.; Jelen, K.; Kisielewska, D.; Kowal, A.M.; Kowalski, T.; Przybycien, M.; Rulikowska-Zarebska, E.; Suszycki, L.; Szuba, D.; Kotanski, A.; Bauerdick, L.A.T.; Behrens, U.; Bienlein, J.K.; Borras, K.; Chiochia, V.; Dannheim, D.; Desler, K.; Drews, G.; Fox-Murphy, A.; Fricke, U.; Goebel, F.; Goers, S.; Goettlicher, P.; Graciani, R.; Haas, T.; Hain, W.; Hartner, G.F.; Hebbel, K.; Hillert, S.; Koch, W.; Koetz, U.; Kowalski, H.; Labes, H.; Loehr, B.; Mankel, R.; Martens, J.; Martinez, M.; Milite, M.; Moritz, M.; Notz, D.; Petrucci, M.C.; Polini, A.; Rohde, M.; Savin, A.A.; Schneekloth, U.; Selonke, F.; Sievers, M.; Stonjek, S.; Wolf, G.; Wollmer, U.; Youngman, C.; Zeuner, W.; Coldewey, C.; Lopez-Duran Viani, A.; Meyer, A.; Schlenstedt, S.[and others
2001-02-26
Differential cross sections for dijet photoproduction in association with a leading neutron using the reaction e{sup +}+p{yields}e{sup +}+n+jet+jet+X{sub r} have been measured with the ZEUS detector at HERA using an integrated luminosity of 6.4 pb{sup -1}. The fraction of dijet events with a leading neutron in the final state was studied as a function of the jet kinematic variables. The cross sections were measured for jet transverse energies E{sub T}{sup jet}>6 GeV, neutron energy E{sub n}>400 GeV, and neutron production angle {theta}{sub n}<0.8 mrad. The data are broadly consistent with factorization of the lepton and hadron vertices and with a simple one-pion-exchange model.
Kitis, G; Wiescher, M; Dahlfors, M; Soares, J
2002-01-01
We propose to measure the neutron capture cross sections of $^{139}$La, of $^{93}$Zr (t$_{1/2}$)=1.5 10$^{6}$ yr), and of all the stable Zr isotopes at n_TOF. The aim of these measurements is to improve the accuracy of existing results by at least a factor of three in order to meet the quality required for using the s-process nucleosynthesis as a diagnostic tool for neutron exposure and neutron flux during the He burning stages of stellar evolution. Combining these results with a wealth of recent information coming from high-resolution stellar spectroscopy and from the detailed analysis of presolar dust grains will shed new light on the chemical history of the universe. The investigated cross sections are also needed for technological applications, in particular since $^{93}$Zr is one of the major long-lived fission products.
New evaluations of neutron cross sections for 14N and 16O
International Nuclear Information System (INIS)
Hale, G.M.; Young, P.G.; Chadwick, M.; Chen, Z.P.
1991-01-01
New evaluations of the neutron cross sections for 14 N and 16 O have been made for ENDF/B=VI. The evaluations are based at low energies on R-matrix analyses of reactions in the 15 N and 17 O systems, and at higher energies on GNASH calculations and experimental data evaluations, including covariance analyses. The 15 N system R-matrix analysis includes data from reactions among the channels n+ 14 N, p+ 14 C, and α+ 11 B at energies corresponding to excitations in 15 N below E x =13 MeV. The resonance structure of all cross sections in this energy range is fairly well reproduced. New data indicate a different J-value for the first resonance, however. Sub-threshold S-wave levels required to explain the large n+ 14 N total and elastic cross sections near zero energy give scattering lengths that differ significantly from the previous values. The R-matrix analysis of the 17 O system includes many new measurements of the n+ 16 O total cross section, done primarily at Oak Ridge and at Karlsruhe. The resonance structure of all the cross sections [total, (n,n), (n,α), and (α,α)] is well represented by the fit in the region below E n = 6.5 MeV. The new total cross section information gives different positions for some of the resonances and implies a different normalization for the (n,α) cross sections than that obtained in the ENDF/B-IV analysis. The evaluations at energies above the ranges of the R-matrix analyses incorporate results from a number of experiments performed since the previous ENDF/B evaluations. Especially important are new measurements of the total cross sections and differential elastic, and gamma-ray production cross sections
Differential bremsstrahlung and pair production cross sections at high energies
International Nuclear Information System (INIS)
Olsen, Haakon A.
2003-01-01
Detailed differential cross sections for high energy bremsstrahlung and pair production are derived with specific attention to the differences between the two processes, which are considerable. For the integrated cross sections, which are the only cross sections specifically known until now, the final state integration theorem guarantees that the exact cross section formulas can be exchanged between bremsstrahlung and pair production by the same substitution rules as for the Born-approximation Bethe-Heitler cross sections, for any amount of atomic screening. In fact the theorem states that the Coulomb corrections to the integrated bremsstrahlung and pair production cross sections are identical for any amount of screening. The analysis of the basic differential cross sections leads to fundamental physical differences between bremsstrahlung and pair production. Coulomb corrections occur for pair production in the strong electric field of the atom for 'large' momentum transfer of the order of mc. For bremsstrahlung, on the other hand, the Coulomb corrections take place at a 'large' distance from the atom of the order of ((ℎ/2π)/mc)ε, with a 'small' momentum transfer mc/ε, where ε is the initial electron energy in units of mc 2 . And the Coulomb corrections can be large, of the order of larger than (Z/137) 2 , which is considerably larger than the integrated cross section corrections
Systematics of new isotopic production cross sections from neon projectiles
International Nuclear Information System (INIS)
Chen, C.X.; Guzik, T.G.; McMahon, M.; Wefel, J.P.; Flores, I.; Lindstrom, P.J.; Tull, C.E.; Mitchell, J.W.; Cronqvist, M.; Crawford, H.J.
1996-02-01
New isotopic production cross sections from 22 Ne projectiles at 377,581 and 891 MeV/nucleon in a liquid hydrogen target have been measured. These data allow to investigate the projectile energy and nuclear composition dependence of the cross sections. The comparisons between data and predictions can have important consequences in source abundance investigations. (K.A.)
Systematics of new isotopic production cross sections from neon projectiles
Energy Technology Data Exchange (ETDEWEB)
Chen, C X; Guzik, T G; McMahon, M; Wefel, J P [Louisiana State Univ., Baton Rouge, LA (United States); Flores, I; Lindstrom, P J; Tull, C E [Lawrence Berkeley Lab., CA (United States); Mitchell, J W [National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center; Cronqvist, M; Crawford, H J [California Univ., Berkeley, CA (United States). Space Sciences Lab.; and others
1996-02-01
New isotopic production cross sections from {sup 22}Ne projectiles at 377,581 and 891 MeV/nucleon in a liquid hydrogen target have been measured. These data allow to investigate the projectile energy and nuclear composition dependence of the cross sections. The comparisons between data and predictions can have important consequences in source abundance investigations. (K.A.). 9 refs.
Cross sections for hadron and lepton production processes
International Nuclear Information System (INIS)
Bhattacharya, R.
1976-01-01
Charged heavy lepton production in proton-proton collisions is studied. Motivated by recent experimental results from the Stanford Linear Accelerator Center a parton model analysis is given of the reaction p + p → L + + L - + x → μ +- + e/ -+ / + neutrinos + x. Results are presented for the total cross section and the differential cross sections with respect to the invariant mass squared of the final charged leptons and the transverse momenta of each one of them. The two-photon mechanism for pair production in colliding beam exeriments is considered. Through the use of mapped invariant integration variables, a reliable exact numerical calculation of the cross section for the production of muon and pion pairs by the two-photon mechanism is provided. Results are given for the exact total cross sections and also the differential cross sections with respect to the invariant mass squared of the pair. These are compared to the results obtained from the equivalent photon approximation method
International Nuclear Information System (INIS)
Ford, W.E. III; Arwood, J.W.; Greene, N.M.; Petrie, L.M.; Primm, R.T. III; Waddell, M.W.; Webster, C.C.; Westfall, R.M.; Wright, R.Q.
1987-01-01
Multigroup P3 neutron, P0-P3 secondary gamma ray production (SGRP), and P6 gamma ray interaction (GRI) cross section libraries have been generated to support design work on the Advanced Neutron Source (ANS) reactor. The libraries, designated ANSL-V (Advanced Neutron Source Cross-Section Libraries), are data bases in a format suitable for subsequent generation of problem dependent cross sections. The ANSL-V libraries are available on magnetic tape from the Radiation Shielding Information Center at Oak Ridge National Laboratory
Consistent evaluation of neutron cross sections for the 242-244Cm isotopes
International Nuclear Information System (INIS)
Ignatyuk, A.V.; Maslov, V.M.
1989-01-01
The knowledge of neutron cross-sections for Curium isotopes is necessary for solving the problems of the external fuel cycle. Experimental information on the cross-sections is very meager and does not satisfy requirements and existing evaluations in different libraries differ substantially for fission and (n,2n) reaction cross-sections. This situation requires a critical review of the entire set of evaluations of the neutron cross-sections for Curium. 17 refs, 3 figs
Evaluated neutron-induced cross sections for 40Ca from 20 to 40 MeV
International Nuclear Information System (INIS)
Hetrick, D.M.; Fu, C.Y.; Larson, D.C.
1982-09-01
Nuclear model codes were used to compute cross sections for neutron-induced reactions on 40 Ca for incident energies from 20 to 40 MeV. The input parameters for the model codes were determined through analysis of experimental data in this energy region. Computed cross sections along with emission spectra for each product were combined into an Evaluated Nuclear Data File (ENDF) using the proposed format for charged-particle reactions. Discussion of the models used, the resulting calculations, and the final evaluated data file are presented
Preparation and benchmarking of ANSL-V cross sections for advanced neutron source reactor studies
International Nuclear Information System (INIS)
Arwood, J.W.; Ford, W.E. III; Greene, N.M.; Petrie, L.M.; Primm, R.T. III; Waddell, M.W.; Webster, C.C.; Westfall, R.M.; Wright, R.Q.
1987-01-01
Research and development for the advanced neutron source (ANS) reactor is being funded by the US Dept. of Energy. This reactor is to provide the world's most intense steady-state source of low-energy neutrons for a national experimental user facility. Pseudo-problem-independent, multigroup cross-section libraries were generated to support ANS design work. The libraries, designated ANSL-V, are data bases in AMPX master format for subsequent generation of problem-dependent cross sections for use with codes such as KENO, ANISN, XSDRNPM, VENTURE, DOT, and MORSE. Included in ANSL-V are 123-material P 3 neutron, 46-material P 0 or P 6 secondary gamma-ray production (SGRP), and 34-material P 6 gamma-ray interaction (GRI) libraries
Neutron, Proton, and Photonuclear Cross Sections for Radiation Therapy and Radiation Protection
International Nuclear Information System (INIS)
Chadwick, M.B.
1998-01-01
The authors review recent work at Los Alamos to evaluate neutron, proton, and photonuclear cross section up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. For radiation protection, these data can be used to determine shielding requirements in accelerator environments, and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross section and kerma coefficient data with measurements are given
Measurement of Dijet Cross Sections in ep Interactions with a Leading Neutron at HERA
Aktas, A.; Anthonis, T.; Aplin, S.; Asmone, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Brown, D.P.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Caron, S.; Cassol-Brunner, F.; Cerny, K.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; Delcourt, B.; Demirchyan, R.; De Roeck, A.; Desch, K.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Ellerbrock, M.; Elsen, E.; Erdmann, W.; Essenov, S.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Felst, R.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Fleming, Y.H.; Flucke, G.; Fomenko, A.; Foresti, I.; Formanek, J.; Franke, G.; Frising, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerhards, R.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grindhammer, Guenter; Gwilliam, C.; Haidt, D.; Hajduk, L.; Haller, J.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Henshaw, O.; Herrera, G.; Herynek, I.; Heuer, R.-D.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, H.; Kapichine, M.; Karlsson, M.; Katzy, J.; Keller, N.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Koutouev, R.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kuckens, J.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Laycock, P.; Lebedev, A.; Leiner, B.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; List, B.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxeld, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, J.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Pascaud, C.; Patel, G.D.; Peez, M.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Poschl, R.; Portheault, B.; Povh, B.; Prideaux, P.; Raicevic, N.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Scheins, J.; Schilling, F.-P.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schroder, V.; Schultz-Coulon, H.-C.; Schwanenberger, C.; Sedlak, K.; Sefkow, F.; Sheviakov, I.; Shtarkov, L.N.; Sirois, Y.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, Marcel; Usik, A.; Utkin, D.; Valkar, S.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Van Remortel, N.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vest, A.; Vinokurova, S.; Volchinski, V.; Vujicic, B.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Werner, N.; Wessels, M.; Wessling, B.; Wigmore, C.; Winter, G.-G.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zimmermann, J.; Zohrabyan, H.; Zomer, F.
2005-01-01
Measurements are reported of the production of dijet events with a leading neutron in ep interactions at HERA. Differential cross sections for photoproduction and deep inelastic scattering are presented as a function of several kinematic variables. Leading order QCD simulation programs are compared with the measurements. Models in which the real or virtual photon interacts with a parton of an exchanged pion are able to describe the data. Next-to-leading order perturbative QCD calculations based on pion exchange are found to be in good agreement with the measured cross sections. The fraction of leading neutron dijet events with respect to all dijet events is also determined. The dijet events with a leading neutron have a lower fraction of resolved photon processes than do the inclusive dijet data.
ENDF/B-5 fission product cross section evaluations
International Nuclear Information System (INIS)
Schenter, R.E.; England, T.R.
1979-12-01
Cross section evaluations were made for the 196 fission product nuclides on the ENDF/B-5 data files. Most of the evaluations involve updating the capture cross sections of the important absorbers for fast and thermal reactor systems. This included updating thermal values, resonance integrals, resonance parameter sets, and fast capture cross sections. For the fast capture results generalized least-squares calculations were made with the computer code FERRET. Input for these cross section adjustments included nuclear models calculations and both integral and differential experimental data results. The differential cross sections and their uncertainties were obtained from the CSIRS library. Integral measurement results came from CFRMF and STEK Assemblies 500, 1000, 2000, 3000, 4000. Comparisons of these evaluations with recent capture measurements are shown. 15 figures, 10 tables
Energy Technology Data Exchange (ETDEWEB)
Iwamoto, Yosuke, E-mail: iwamoto.yosuke@jaea.go.j [Japan Atomic Energy Agency, 2-4, Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Satoh, Daiki [Japan Atomic Energy Agency, 2-4, Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Hagiwara, Masayuki [KEK (Japan); Yashima, Hiroshi [Kyoto University (Japan); Nakane, Yoshihiro [Japan Atomic Energy Agency, 2-4, Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Tamii, Atsushi [Research Center for Nuclear Physics, Osaka University (Japan); Iwase, Hiroshi [KEK (Japan); Endo, Akira; Nakashima, Hiroshi; Sakamoto, Yukio [Japan Atomic Energy Agency, 2-4, Shirakatashirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Hatanaka, Kichiji [Research Center for Nuclear Physics, Osaka University (Japan); Niita, Koji [Research Organization for Information Science and Technology (Japan)
2010-08-21
The neutron production cross-sections of carbon, iron, and gold targets with 140 MeV protons at 180{sup o} were measured at the RCNP cyclotron facility. The time-of-flight technique was used to obtain the neutron energy spectra in the energy range above 1 MeV. The carbon and iron target results were compared with the experimental data from 113 MeV (p,xn) reactions at 150{sup o} reported by Meier et al. Our data agreed well with them in spite of different incident energies and angles. Calculations were then performed using different intra-nuclear cascade models (Bertini, ISOBAR, and JQMD) implemented with PHITS code. The results calculated using the ISOBAR and JQMD models roughly agreed with the experimental iron and gold target data, but the Bertini could not reproduce the high-energy neutrons above 10 MeV.
Neutron cross-section library for SAND-2 and its service program
International Nuclear Information System (INIS)
Berzonis, M.A.; Bondars, Kh.Ya.; Lapenas, A.A.
1978-01-01
The logical structure of the neutron cross-section library used in the SAND-2 program complex is considered. The organization of the DSIG01 program creating and servicing the neutron cross section library is described. The DSIG 01 program is written on FORTRAN and permits to create the neutron cross section library on the ES computer magnetic discs operating under the control of the ES operating system and to perform certain manipulations therewith
Measurements of neutron cross section of the {sup 243}Am(n,{gamma}){sup 244}Am reaction
Energy Technology Data Exchange (ETDEWEB)
Hatsukawa, Yuichi; Shinohara, Nobuo; Hata, Kentaro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
1998-03-01
The effective thermal neutron cross section of {sup 243}Am(n,{gamma}){sup 244}Am reaction was measured by the activation method. Highly-purified {sup 243}Am target was irradiated in an aluminum capsule by using a research reactor JRR-3M. The tentative effective thermal neutron cross sections are 3.92 b, and 84.44 b for the production of {sup 244g}Am and {sup 244m}Am, respectively. (author)
Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; Blyth, D.; Bowman, J. D.; Calarco, J.; Crawford, C.; Craycraft, K.; Evans, D.; Fomin, N.; Fry, J.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Hamblen, J.; Hayes, C.; Kucuker, S.; Mahurin, R.; Maldonado-Velázquez, M.; Martin, E.; McCrea, M.; Mueller, P. E.; Musgrave, M.; Nann, H.; Penttilä, S. I.; Snow, W. M.; Tang, Z.; Wilburn, W. S.
2015-05-01
Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. Unfortunately, the pair correlation function g (r ) inferred from neutron scattering measurements of the differential cross section d/σ d Ω from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43 and 16.1 meV on liquid hydrogen at 15.6 K (which is dominated by the parahydrogen component) using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1 meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra nonequilibrium component of orthohydrogen. Liquid parahydrogen is also a widely used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. We describe our measurements and compare them with previous work.
Neutron-capture cross sections from indirect measurements
Directory of Open Access Journals (Sweden)
Scielzo N.D.
2012-02-01
Full Text Available Cross sections for compound-nuclear reactions reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f reactions, but need to be improved upon for applications to capture reactions.
Neutron-capture Cross Sections from Indirect Measurements
Energy Technology Data Exchange (ETDEWEB)
Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J
2011-10-18
Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.
Analytical methods for analysis of neutron cross sections of amino acids and proteins
International Nuclear Information System (INIS)
Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin; Carvalheira, Luciana; Rocha, Hélio F. da
2017-01-01
Two unpublished analytical processes were developed at IEN-CNEN-RJ for the analysis of neutron cross sections of chemical compounds and complex molecules, the method of data parceling and grouping (P and G) and the method of data equivalence and similarity (E and S) of cross-sections. The former allows the division of a complex compound or molecule so that the parts can be manipulated to construct a value of neutron cross section for the compound or the entire molecule. The second method allows by comparison obtain values of neutron cross-sections of specific parts of the compound or molecule, as the amino acid radicals or its parts. The processes were tested for the determination of neutron cross-sections of the 20 human amino acids and a small database was built for future use in the construction of neutron cross-sections of proteins and other components of the human being cells, also in other industrial applications. (author)
Analytical methods for analysis of neutron cross sections of amino acids and proteins
Energy Technology Data Exchange (ETDEWEB)
Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin; Carvalheira, Luciana, E-mail: dante@ien.gov.br, E-mail: fferreira@ien.gov.br, E-mail: Chaffin@ien.gov.br, E-mail: luciana@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rocha, Hélio F. da, E-mail: helionutro@gmail.com.br [Universidade Federal do Rio de Janeiro (IPPMG/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Pediatria
2017-07-01
Two unpublished analytical processes were developed at IEN-CNEN-RJ for the analysis of neutron cross sections of chemical compounds and complex molecules, the method of data parceling and grouping (P and G) and the method of data equivalence and similarity (E and S) of cross-sections. The former allows the division of a complex compound or molecule so that the parts can be manipulated to construct a value of neutron cross section for the compound or the entire molecule. The second method allows by comparison obtain values of neutron cross-sections of specific parts of the compound or molecule, as the amino acid radicals or its parts. The processes were tested for the determination of neutron cross-sections of the 20 human amino acids and a small database was built for future use in the construction of neutron cross-sections of proteins and other components of the human being cells, also in other industrial applications. (author)
Status of measured neutron cross sections of transactinium isotopes in the fast region
International Nuclear Information System (INIS)
Igarasi, S.
1976-01-01
This paper reviews present status of measured neutron cross sections of transactinium isotopes from a viewpoint of requested data in application field of the nuclear data. The measured cross sections from 1 keV to 15 MeV are examined. Comparison between different data sets is mainly performed on the fission cross sections
Evaluation of Cross-Section Sensitivities in Computing Burnup Credit Fission Product Concentrations
International Nuclear Information System (INIS)
Gauld, I.C.
2005-01-01
U.S. Nuclear Regulatory Commission Interim Staff Guidance 8 (ISG-8) for burnup credit covers actinides only, a position based primarily on the lack of definitive critical experiments and adequate radiochemical assay data that can be used to quantify the uncertainty associated with fission product credit. The accuracy of fission product neutron cross sections is paramount to the accuracy of criticality analyses that credit fission products in two respects: (1) the microscopic cross sections determine the reactivity worth of the fission products in spent fuel and (2) the cross sections determine the reaction rates during irradiation and thus influence the accuracy of predicted final concentrations of the fission products in the spent fuel. This report evaluates and quantifies the importance of the fission product cross sections in predicting concentrations of fission products proposed for use in burnup credit. The study includes an assessment of the major fission products in burnup credit and their production precursors. Finally, the cross-section importances, or sensitivities, are combined with the importance of each major fission product to the system eigenvalue (k eff ) to determine the net importance of cross sections to k eff . The importances established the following fission products, listed in descending order of priority, that are most likely to benefit burnup credit when their cross-section uncertainties are reduced: 151 Sm, 103 Rh, 155 Eu, 150 Sm, 152 Sm, 153 Eu, 154 Eu, and 143 Nd
Hue, B. M.; Isataev, T.; Erdemchimeg, B.; Artukh, A. G.; Aznabaev, D.; Davaa, S.; Klygin, S. A.; Kononenko, G. A.; Khuukhenkhuu, G.; Kuterbekov, K.; Lukyanov, S. M.; Mikhailova, T. I.; Maslov, V. A.; Mendibaev, K.; Sereda, Yu M.; Penionzhkevich, Yu E.; Vorontsov, A. N.
2017-12-01
Preliminary results of measurements of the total reaction cross sections σR and neutron removal cross section σ-xn for weakly bound 6He, 8Li, 9Be and 10Be nuclei at energy range (20-35) A MeV with 28Si target is presented. The secondary beams of light nuclei were produced by bombardment of the 22Ne (35 A MeV) primary beam on Be target and separated by COMBAS fragment-separator. In dispersive focal plane a horizontal slit defined the momentum acceptance as 1% and a wedge degrader of 200 μm Al was installed. The Bρ of the second section of the fragment-separator was adjusted for measurements in energy range (20-35) A MeV. Two-neutron removal cross sections for 6He and 10Be and one -neutron removal cross sections 8Li and 9Be were measured.
Neutron Capture Cross Section of Unstable Ni63: Implications for Stellar Nucleosynthesis
Lederer, C.; Massimi, C.; Altstadt, S.; Andrzejewski, J.; Audouin, L.; Barbagallo, M.; Bécares, V.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Billowes, J.; Boccone, V.; Bosnar, D.; Brugger, M.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Carrapiço, C.; Cerutti, F.; Chiaveri, E.; Chin, M.; Colonna, N.; Cortés, G.; Cortés-Giraldo, M. A.; Diakaki, M.; Domingo-Pardo, C.; Duran, I.; Dressler, R.; Dzysiuk, N.; Eleftheriadis, C.; Ferrari, A.; Fraval, K.; Ganesan, S.; García, A. R.; Giubrone, G.; Gómez-Hornillos, M. B.; Gonçalves, I. F.; González-Romero, E.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Gurusamy, P.; Jenkins, D. G.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karadimos, D.; Kivel, N.; Koehler, P.; Kokkoris, M.; Korschinek, G.; Krtička, M.; Kroll, J.; Langer, C.; Leeb, H.; Leong, L. S.; Losito, R.; Manousos, A.; Marganiec, J.; Martínez, T.; Mastinu, P. F.; Mastromarco, M.; Meaze, M.; Mendoza, E.; Mengoni, A.; Milazzo, P. M.; Mingrone, F.; Mirea, M.; Mondelaers, W.; Paradela, C.; Pavlik, A.; Perkowski, J.; Pignatari, M.; Plompen, A.; Praena, J.; Quesada, J. M.; Rauscher, T.; Reifarth, R.; Riego, A.; Roman, F.; Rubbia, C.; Sarmento, R.; Schillebeeckx, P.; Schmidt, S.; Schumann, D.; Tagliente, G.; Tain, J. L.; Tarrío, D.; Tassan-Got, L.; Tsinganis, A.; Valenta, S.; Vannini, G.; Variale, V.; Vaz, P.; Ventura, A.; Versaci, R.; Vermeulen, M. J.; Vlachoudis, V.; Vlastou, R.; Wallner, A.; Ware, T.; Weigand, M.; Weiß, C.; Wright, T. J.; Žugec, P.
2013-01-01
The Ni63(n,γ) cross section has been measured for the first time at the neutron time-of-flight facility n_TOF at CERN from thermal neutron energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian averaged cross sections were calculated for thermal energies from kT=5-100keV with uncertainties around 20%. Stellar model calculations for a 25M⊙ star show that the new data have a significant effect on the s-process production of Cu63, Ni64, and Zn64 in massive stars, allowing stronger constraints on the Cu yields from explosive nucleosynthesis in the subsequent supernova.
International Nuclear Information System (INIS)
Vonach, H.
1980-06-01
The cross-sections for the four important neutron dosimetry reactions 19 F(n,2n) 18 F, 31 P(n,p) 31 Si, 93 Nb(n,n')sup(93m)Nb and 103 Rh(n,n')sup(103m)Rh were evaluated in the neutron energy range from threshold to 20 MeV. For the 19 F(n,2n) reaction the evaluation could be based entirely on experimental data; for the reactions 31 P(n,p) 31 Si and 103 Rh(n,n')sup(103m)Rh large gaps in the experimental excitation functions and large discrepancies between the existing data made it necessary to supplement the experimental data by cross-section calculations and to give about equal weight to the experimental and calculated cross-sections. For the 93 Nb(n,n')sup(93m)Nb reaction the evaluation had to be based entirely on the theoretically calculated cross-sections. The cross-section calculations were performed using the statistical model of nuclear reactions allowing for precompound processes in the first reaction step and errors of the calculated cross-sections were estimated from their sensitivity to the various input parameters. Cross-section values were evaluated for energy groups between 0.1 MeV and 1 MeV wide, the width depending on both the slope of the excitation functions and the density of the available data. For each evaluated cross-section also an uncertainty (on a 1 sigma confidence level) was derived taking into account the errors given by the experimentalists, the general consistency of the experimental data and the estimated errors of the theoretically calculated cross-sections. In addition relative correlation matrices were derived for each evaluated excitation function describing the correlations between the uncertainties of the cross-sections at different energies. The correlations between the cross-section uncertainties for different reactions were found to be negligible. The results of this evaluation as well as those of Ref. 1 will be combined with the ENDF/B-V dosimetry file into an international neutron dosimetry file by the nuclear data section of
Inelastic neutron spectra and cross sections for 238 U
International Nuclear Information System (INIS)
Kornilov, N.V.; Kagalenko, A.V.
1994-01-01
The report discusses the experimental facilities of IPPE, results of spectra and cross sections investigations. The problems of existing data libraries were highlighted. Some of these problems for example, inelastic spectra at high energy may be solved by correct theoretical calculation. Others like level cross sections at E > 2 MeV and the possible structure of excitation function for group levels between 0.5 to 0.85 MeV demand new experimental efforts. 21 refs., 11 figs., 5 tabs
Energy Technology Data Exchange (ETDEWEB)
Muhrer, G., E-mail: muhrer@lanl.gov [Los Alamos National Laboratory, Los Alamos, 87545 NM (United States); Hartl, M.; Mocko, M.; Tovesson, F.; Daemen, L. [Los Alamos National Laboratory, Los Alamos, 87545 NM (United States)
2012-07-21
In the search for moderator materials encapsulated materials have been discussed, but very little is known regarding the effect of encapsulation on neutron moderation properties. As a first step toward a better understanding, we present the measured total neutron cross-section of water confined in silica microspheres and compare the measured data to the predicted theoretical cross-section.
The total neutron cross sections for 14N and 24Mg
International Nuclear Information System (INIS)
Bommer, J.
This report contains tables of the total neutron cross sections of 14 N and 24 Mg as determined in a recent measurement for neutron energies between 1 and 5.3 MeV. Graphic representations and details on the evaluation of the cross sections are included. (orig.) [de
International Nuclear Information System (INIS)
Alonso V, G.; Viais J, J.
1990-10-01
There is developed a method to generate the library of neutron cross sections for the Thermos code by means of the database ENDF-B/IV and the NJOY code. The obtained results are compared with the version previous of the library of neutron cross sections which was processed using the version ENDF-B/III. (Author)
A computer code for calculating neutron cross-sections from resonance parameter data
International Nuclear Information System (INIS)
Mill, A.J.
1979-08-01
A computer code, XSEC, has been written which calculates neutron cross-sections from resonance data. Although the program was originally written in order to identify neutron 'windows' in enriched nuclides, it may be used to evaluate the total neutron cross-section of any medium mass nuclide at intermediate energies. XSEC has proved very useful in identifying suitable nuclides for use as neutron filters at intermediate energies. (author)
Heavy flavour hadro-production cross-sections
Wöhri, H K
2003-01-01
Hadro-production data on charm and beauty absolute cross-sections, collected by experiments at CERN, DESY and Fermilab, are reviewed. The measurements, corrected for the 'time evolution' of the branching ratios, are compared to calculations done with Pythia, as a function of the collision energy, using the latest parametrizations of the parton densities. We then estimate some charm and beauty production cross-sections relevant for future measurements, including nuclear effectes in the PDFs. We finish by briefly addressing the relevance, in heavy-ion collisions, of beauty production as feed-down for J/psi production.
International Nuclear Information System (INIS)
Konshin, V.A.
1981-01-01
Neutron cross section calculational methods for actinides in the unresolved resonance energy range (1-150 kev) are discussed, with a special emphasis on calculation of width fluctuation factors for the generalized distribution, as well as for a sub-threshold fission. It is shown that the energy dependence of sub(J), the (n,n') -process competition and the structure in neutron cross section has to be taken into account in the energy range considered. Analysis of different approaches in the statistical theory for heavy nuclei neutron cross-section calculation is given, and it is shown to be important to allow for the (n,γf)-reaction in neutron cross section calculations for fissile nuclei. The use of the non-spherical potential, the Lorentzian spectral factor and the Fermi-gas model involving the collective modes enables to obtain the self-consistent data for all neutron cross sections, including σnγ. (author)
Vagelatos, Nicholas; Steinman, Donald K.; John, Joseph; Young, Jack C.
1981-01-01
A nuclear method and apparatus determines the temperature of a medium by injecting fast neutrons into the medium and detecting returning slow neutrons in three first energy ranges by producing three respective detection signals. The detection signals are combined to produce three derived indicia each systematically related to the population of slow neutrons returning from the medium in a respective one of three second energy ranges, specifically exclusively epithermal neutrons, exclusively substantially all thermal neutrons and exclusively a portion of the thermal neutron spectrum. The derived indicia are compared with calibration indicia similarly systematically related to the population of slow neutrons in the same three second energy ranges returning from similarly irradiated calibration media for which the relationships temperature, neutron absorption cross section and neutron moderating power to such calibration indicia are known. The comparison indicates the temperature at which the calibration indicia correspond to the derived indicia and consequently the temperature of the medium. The neutron absorption cross section and moderating power of the medium can be identified at the same time.
The evaluation of neutron total cross section for natural iron and aluminium
International Nuclear Information System (INIS)
Liu Shirui; Wang Chunhao; Zhao Defang
1990-05-01
The experimental data of total cross section were collected and evaluated for natural iron in the energy region from 1 keV to 20 MeV and for natural aluminium from 4.07 keV to 20 MeV. The evaluated data were recommended in the regions for them. The minimum values of Fe total cross section in the keV region were specially recommended. The resonance structures were briefly discussed for both Fe and Al. To make the evaluation better, all experimental measurements of neutron total cross section relative to Fe and Al were studied. Considering the resonance feature of medium weight nuclides, two criteria for selecting total cross section were presented: 1) the correlation between the precission of total cross section and neutron source; 2) the correlation between the accuracy of total cross section and the resolving power of the neutron spectrometer
Simple, empirical approach to predict neutron capture cross sections from nuclear masses
Couture, A.; Casten, R. F.; Cakirli, R. B.
2017-12-01
Background: Neutron capture cross sections are essential to understanding the astrophysical s and r processes, the modeling of nuclear reactor design and performance, and for a wide variety of nuclear forensics applications. Often, cross sections are needed for nuclei where experimental measurements are difficult. Enormous effort, over many decades, has gone into attempting to develop sophisticated statistical reaction models to predict these cross sections. Such work has met with some success but is often unable to reproduce measured cross sections to better than 40 % , and has limited predictive power, with predictions from different models rapidly differing by an order of magnitude a few nucleons from the last measurement. Purpose: To develop a new approach to predicting neutron capture cross sections over broad ranges of nuclei that accounts for their values where known and which has reliable predictive power with small uncertainties for many nuclei where they are unknown. Methods: Experimental neutron capture cross sections were compared to empirical mass observables in regions of similar structure. Results: We present an extremely simple method, based solely on empirical mass observables, that correlates neutron capture cross sections in the critical energy range from a few keV to a couple hundred keV. We show that regional cross sections are compactly correlated in medium and heavy mass nuclei with the two-neutron separation energy. These correlations are easily amenable to predict unknown cross sections, often converting the usual extrapolations to more reliable interpolations. It almost always reproduces existing data to within 25 % and estimated uncertainties are below about 40 % up to 10 nucleons beyond known data. Conclusions: Neutron capture cross sections display a surprisingly strong connection to the two-neutron separation energy, a nuclear structure property. The simple, empirical correlations uncovered provide model-independent predictions of
Trippella, O.; La Cognata, M.
2017-03-01
The {}13{{C}}{(α ,n)}16{{O}} reaction is considered to be the main neutron source responsible for the production of heavy nuclides (from {Sr} to {Bi}) through slow n-capture nucleosynthesis (s-process) at low temperatures during the asymptotic giant branch phase of low-mass stars (≲ 3{--}4 {M}⊙ , or LMSs). In recent years, several direct and indirect measurements have been carried out to determine the cross section at the energies of astrophysical interest (around 190+/- 40 {keV}). However, they yield inconsistent results that cause a highly uncertain reaction rate and affect the neutron release in LMSs. In this work we have combined two indirect approaches, the asymptotic normalization coefficient and the Trojan horse method, to unambiguously determine the absolute value of the {}13{{C}}{(α ,n)}16{{O}} astrophysical factor. With these, we have determined a very accurate reaction rate to be introduced into astrophysical models of s-process nucleosynthesis in LMSs. Calculations using this recommended rate have shown limited variations in the production of those neutron-rich nuclei (with 86≤slant A≤slant 209) that receive contribution only by slow neutron captures.
7Li neutron-induced elastic scattering cross section measurement using a slowing-down spectrometer
Directory of Open Access Journals (Sweden)
Heusch M.
2010-10-01
Full Text Available A new integral measurement of the 7Li neutron induced elastic scattering cross section was determined in a wide neutron energy range. The measurement was performed on the LPSC-PEREN experimental facility using a heterogeneous graphite-LiF slowing-down time spectrometer coupled with an intense pulsed neutron generator (GENEPI-2. This method allows the measurement of the integral elastic scattering cross section in a slowing-down neutron spectrum. A Bayesian approach coupled to Monte Carlo calculations was applied to extract naturalC, 19F and 7Li elastic scattering cross sections.
Thermal neutron capture cross section for the K isomer 177Lum
International Nuclear Information System (INIS)
Belier, G.; Roig, O.; Daugas, J.-M.; Giarmana, O.; Meot, V.; Letourneau, A.; Marie, F.; Foucher, Y.; Aupiais, J.; Abt, D.; Jutier, Ch.; Le Petit, G.; Bettoni, C.; Gaudry, A.; Veyssiere, Ch.; Barat, E.; Dautremer, T.; Trama, J.-Ch.
2006-01-01
The thermal neutron radiative capture cross section for the K isomeric state in 177 Lu has been measured for the first time. Several 177 Lu m targets have been prepared and irradiated in various neutron fluxes at the Lauee Langevin Institute in Grenoble and at the CEA reactors OSIRIS and ORPHEE in Saclay. The method consists of measuring the 178 Lu activity by γ-ray spectroscopy. The values obtained in four different neutron spectra have been used to calculate the resonance integral of the radiative capture cross section for 177 Lu m . In addition, an indirect method leads to the determination of the 177 Lu g neutron radiative capture cross section
International Nuclear Information System (INIS)
Cullen, D.E.
1979-01-01
A code, SIGMAL, to Doppler-broaden evaluated cross sections in the ENDL format was designed. This code can Doppler-broaden cross sections that result from neutrons, protons, deuterons, tritons, 3 He, or alpha particles incident on any target nuclei. The code allows broadening to up to 100 final temperatures, either directly from the initial temperature or by bootstrapping to successively higher temperatures. 6 figures, 2 tables
PCS a code system for generating production cross section libraries
International Nuclear Information System (INIS)
Cox, L.J.
1997-01-01
This document outlines the use of the PCS Code System. It summarizes the execution process for generating FORMAT2000 production cross section files from FORMAT2000 reaction cross section files. It also describes the process of assembling the ASCII versions of the high energy production files made from ENDL and Mark Chadwick's calculations. Descriptions of the function of each code along with its input and output and use are given. This document is under construction. Please submit entries, suggestions, questions, and corrections to (ljc at sign llnl.gov) 3 tabs
Measurements of Neutron Induced Cross Sections at the Oak Ridge Electron Linear Accelerator
International Nuclear Information System (INIS)
Guber, K.H.; Harvey, J.A.; Hill, N.W.; Koehler, P.E.; Leal, L.C.; Sayer, R.O.; Spencer, R.R.
1999-01-01
We have used the Oak Ridge Electron Linear Accelerator (ORELA) to measure neutron total and the fission cross sections of 233 U in the energy range from 0.36 eV to 700 keV. We report average fission and total cross sections. Also, we measured the neutron total cross sections of 27 Al and Natural chlorine as well as the capture cross section of Al over an energy range from 100 eV up to about 400 keV
Neutron-induced capture cross sections via the surrogate reaction method
International Nuclear Information System (INIS)
Boutoux, G.; Jurado, B.; Aiche, M.; Barreau, G.; Capellan, N.; Companis, I.; Czajkowski, S.; Dassie, D.; Haas, B.; Mathieu, L.; Meot, V.; Bail, A.; Bauge, E.; Daugas, J. M.; Faul, T.; Gaudefroy, L.; Morel, P.; Pillet, N.; Roig, O.; Romain, P.; Taieb, J.; Theroine, C.; Burke, J.T.; Companis, I.; Derkx, X.; Gunsing, F.; Matea, I.; Tassan-Got, L.; Porquet, M.G.; Serot, O.
2011-01-01
The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. This technique enables neutron-induced cross sections to be extracted for nuclear reactions on short-lived unstable nuclei that otherwise can not be measured. This technique has been successfully applied to determine the neutron-induced fission cross sections of several short-lived nuclei. In this work, we investigate whether this powerful technique can also be used to determine of neutron-induced capture cross sections. For this purpose we use the surrogate reaction 174 Yb( 3 He, pγ) 176 Lu to infer the well known 175 Lu(n, γ) cross section and compare the results with the directly measured neutron-induced data. This surrogate experiment has been performed in March 2010. The experimental technique used and the first preliminary results will be presented. (authors)
Evaluation of the neutron cross sections for Pu-240
International Nuclear Information System (INIS)
Weston, L.W.; Arthur, E.D.
1987-04-01
The present evaluation is proposed to supersede the ENDF/B-V, Revision 2 file for 240 Pu. In this work, resonance parameters, cross sections, energy distributions, and angular distributions have been modified. These changes are outlined in detail and appropriate references included. 37 refs., 21 figs., 2 tabs
Measurement of the neutron capture cross-section of 232Th using the neutron activation technique
International Nuclear Information System (INIS)
Naik, H.; Singh, Sarbjit; Goswami, A.; Manchanda, V.K.; Prajapati, P.M.; Surayanarayana, S.V.; Nayak, B.K.; Sharma, S.C.; Jagadeesan, K.C.; Thakare, S.V.; Raj, D.; Ganesan, S.; Mulik, V.K.; Sivashankar, B.S.; Mukherjee, S.
2011-01-01
The 232 Th(n, γ) reaction cross-section at average neutron energies of 3.7±0.3 MeV and 9.85±0.38 MeV from the 7 Li(p, n) reaction has been determined for the first time using activation and off-line γ -ray spectrometric technique. The 232 Th(n, 2n) reaction cross-section at the average neutron energy of 9.85±0.38 MeV has been also determined using the same technique. The experimentally determined 232 Th(n, γ) and 232 Th(n, 2n) reaction cross-sections were compared with the evaluated data of ENDF/B-VII, JENDL-4.0 and JEFF-3.1 and were found to be in good agreement. The present data along with literature data in a wide range of neutron energies were interpreted in terms of competition between different reaction channels including fission. The 232 Th(n, γ) and 232 Th(n, 2n) reaction cross-sections were also calculated theoretically using the TALYS 1.2 computer code and were found to be slightly higher than the experimental data. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Drake, D.M.; Auchampaugh, G.F.; Arthur, E.D.; Ragan, C.E.; Young, P.G.
1976-08-01
Beryllium neutron-production cross sections were measured using the time-of-flight technique at incident neutron energies of 5.9, 10.1, and 14.2 MeV, and at laboratory angles of 25, 27.5, 30, 35, 45, 60, 80, 100, 110, 125, and 145/sup 0/. The differential elastic and inelastic cross sections are presented. Inelastic is defined here as those reactions that proceed through the states at 1.69-, 2.43-, 2.8-, and 3.06-MeV excitation energy in /sup 9/Be. Comparison of emission energy spectra with calculations using the ENDF/B-IV beryllium cross sections shows that the ENDF/B cross sections strongly overemphasize the low lying states in /sup 9/Be.
Energy Technology Data Exchange (ETDEWEB)
Ertaud, A; Beauge, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1953-07-01
In this report, we done on the reactor of Chatillon analogous experiences to those of Fermi in Argonne. The temperature of the neutrons filtered ba a more or less thickness of graphite is measured by the method of absorption. This method permits the production and the study of a very low energy neutron beam. (M.B.) [French] Dans ce rapport, nous avons repris sur la pile de Chatillon des experiences analogues a celles de FERMI a Argonne. La temperature des neutrons filtree par une epaisseur plus ou moins grande de graphite est mesuree par la methode d'absorption. Cette methode permettant la production et l'etude d'un faisceau de neutron de tres basse energie. (M.B.)
Evaluation of Cm-247 neutron cross sections in the resonance region
International Nuclear Information System (INIS)
Martinelli, T.; Menapace, E.; Motta, M.; Vaccari, M.
1980-01-01
The neutron cross sections of Cm-247 are evaluated in the resonance (resolved and unresolved) region up to 10 keV. Average resonance parameters (i.e. spacing D, fission and radiative widths, neutron strength functions) are determined for unresolved region calculations. Moreover for a better comparison with the experimental data, fission cross section is calculated up to 10 MeV. In addition, the average number of neutrons emitted per fission as a function of energy is estimated
Theoretical and experimental cross sections for neutron reactions on 64Zinc
International Nuclear Information System (INIS)
Rutherford, D.A.
1987-01-01
Accurate measurements of the 64 Zn (n,2n) 64 Cu and 64 Zn (n,p) 63 Zn cross sections at 14.8 MeV have been made using a Texas Nuclear Neutron Generator and the activation technique. A NaI(T1) spectrometer (using two 6'' x 6'' NaI detectors/crystals) was used to measure the gamma radiation emitted in coincidence from the positron-emitting decay products. The measurements were made relative to 65 Cu (n,2n) /64/Cu and 63 Cu (n,2n) 62 Cu cross sections, which have similar half-lives, radiation emission, and were previously measured to high accuracy (2 percent). The value obtained for the (n,2n) measurement was 199 /+-/ 6 millibarns, and a value of 176 /+-/ 4.5 millibarns was obtained for the (n,p) measurement. In concert, a theoretical analysis of neutron induced reactions on /64/Zn was performed at Los Alamos National Laboratory using the Hauser-Feshbach statistical theory in the GNASH code over an energy range of 100 keV to 20 MeV. Calculations included width fluctuation corrections, direct reaction contributions, and preequilibrium corrections above 6 MeV. Neutron optical model potentials were determined for zinc. The theoretical values agree with the new 14.8 MeV measurements approximately within experimental error, with calculations of 201 millibarns for the (n,2n) cross section and 170 millibarns for the (n,p) cross section. Results from the analysis will be made available in National Evaluated Nuclear Data Format (ENDF/B) for fusion energy applications. 50 refs., 34 figs., 10 tabs
Neutron total cross section measurements of gold and tantalum at the nELBE photoneutron source
Hannaske, Roland; Beyer, Roland; Junghans, Arnd; Bemmerer, Daniel; Birgersson, Evert; Ferrari, Anna; Grosse, Eckart; Kempe, Mathias; Kögler, Toni; Marta, Michele; Massarczyk, Ralph; Matic, Andrija; Schramm, Georg; Schwengner, Ronald; Wagner, Andreas
2014-01-01
Neutron total cross sections of 197 Au and nat Ta have been measured at the nELBE photoneutron source in the energy range from 0.1 - 10 MeV with a statistical uncertainty of up to 2 % and a total systematic uncertainty of 1 %. This facility is optimized for the fast neutron energy range and combines an excellent t ime structure of the neutron pulses (electron bunch width 5 ps) with a short flight path of 7 m. Because of the low instantaneous neutron flux transmission measurements of neutron total cross sections are possible, that exhibit very different beam and back ground conditions than found at other neutron sources.
International Nuclear Information System (INIS)
Genreith, Christoph
2015-01-01
Nuclear waste needs to be characterized for its safe handling and storage. In particular long-lived actinides render the waste characterization challenging. The results described in this thesis demonstrate that Prompt Gamma Neutron Activation Analysis (PGAA) with cold neutrons is a reliable tool for the non-destructive analysis of actinides. Nuclear data required for an accurate identification and quantification of actinides was acquired. Therefore, a sample design suitable for accurate and precise measurements of prompt γ-ray energies and partial cross sections of long-lived actinides at existing PGAA facilities was presented. Using the developed sample design the fundamental prompt γ-ray data on 237 Np, 241 Am and 242 Pu were measured. The data were validated by repetitive analysis of different samples at two individual irradiation and counting facilities - the BRR in Budapest and the FRM II in Garching near Munich. Employing cold neutrons, resonance neutron capture by low energetic resonances was avoided during the experiments. This is an improvement over older neutron activation based works at thermal reactor neutron energies. 152 prompt γ-rays of 237 Np were identified, as well as 19 of 241 Am, and 127 prompt γ-rays of 242 Pu. In all cases, both high and lower energetic prompt γ-rays were identified. The most intense line of 237 Np was observed at an energy of E γ =182.82(10) keV associated with a partial capture cross section of σ γ =22.06(39) b. The most intense prompt γ-ray lines of 241 Am and of 242 Pu were observed at E γ =154.72(7) keV with σ γ =72.80(252) b and E γ =287.69(8) keV with σ γ =7.07(12) b, respectively. The measurements described in this thesis provide the first reported quantifications on partial radiative capture cross sections for 237 Np, 241 Am and 242 Pu measured simultaneously over the large energy range from 45 keV to 12 MeV. Detailed uncertainty assessments were performed and the validity of the given uncertainties was
Measurement of Charmonium Production Cross Section at LHCb
Frosini, M
2010-01-01
The great abundance of charmonium states, collected from the start up of LHC, allows to study its production mechanism. In particular the total and differential $J/\\psi$ production cross section are measured in the transverse momentum range [0;10] GeV/$c$ and in the pseudorapidity range $y \\in$ [2.5;4]. The measurements are performed disentagling the prompt (direct production in $pp$ collisions and feed down from excited charmonium states) and delayed ($b$-hadron decays products) component.
Capital yields assessment trough cross section production function
Czech Academy of Sciences Publication Activity Database
Kodera, Jan; Pánková, V.
2001-01-01
Roč. 8, č. 14 (2001), s. 79-87 ISSN 1212-074X R&D Projects: GA ČR GA402/00/0439 Institutional research plan: AV0Z1075907 Keywords : yield of capital * cross-section production function * maximisation of profit Subject RIV: AH - Economics
Neutron cross section standards for the energy region above 20 MeV
International Nuclear Information System (INIS)
1991-01-01
These proceedings of a specialists' meeting on Neutron cross section standards for the energy region above 20 MeV are divided into 6 sessions bearing on: - session 1: status of the date base for (n-p) scattering (2 conferences) - session 2: status of nucleon-nucleon phase shift calculations (1 conference) - session 3: recent and planned experimental work on n-p cross section measurements and facilities (7 conferences) - session 4: Instruments for utilizing the H (n.n) standard for neutron fluence measurement (4 conferences) - session 5: proposal for other neutron cross-section standards (4 conferences) - session 6: monitor reactions for radiation dosimetry (3 conferences)
Remarks on the comparison of cross section libraries for neutron metrology
International Nuclear Information System (INIS)
Zijp, W.L.; Nolthenius, H.J.; Appelman, K.H.
1977-01-01
Cross section libraries in a 620 group structure were available from different origin: CCC-112B, DETAN-74 and ENDF/B-IV. For a few well known neutron spectra (CFRMF spectrum, ΣΣ spectrum, fission neutron spectrum, HFR neutron spectrum) a comparison was made of the available experimental reaction rates in foil detectors and the reaction rates as calculated with the different cross section libraries. This investigation is dealing with the consistency of cross section data within a library, and the consistency of activity data in actual reaction rate determinations. Some preliminary conclusions are given
Library of neutron cross sections of the Thermos code
International Nuclear Information System (INIS)
Alonso V, G.; Hernandez L, H.
1991-10-01
The present work is the complement of the IT.SN/DFR-017 report in which the structure and the generation of the library of the Thermos code is described. In this report the comparison among the values of the cross sections that has the current library of the Thermos code and those generated by means of the ENDF-B/NJOY it is shown. (Author)
Contribution to uncertainties evaluation for fast reactors neutronic cross sections
International Nuclear Information System (INIS)
Privas, Edwin
2015-01-01
The thesis has been motivated by a wish to increase the uncertainty knowledge on nuclear data, for safety criteria. It aims the cross sections required by core calculation for sodium fast reactors (SFR), and new tools to evaluate its.The main objective of this work is to provide new tools in order to create coherent evaluated files, with reliable and mastered uncertainties. To answer those problematic, several methods have been implemented within the CONRAD code, which is developed at CEA of Cadarache. After a summary of all the elements required to understand the evaluation world, stochastic methods are presented in order to solve the Bayesian inference. They give the evaluator more information about probability density and they also can be used as validation tools. The algorithms have been successfully tested, despite long calculation time. Then, microscopic constraints have been implemented in CONRAD. They are defined as new information that should be taken into account during the evaluation process. An algorithm has been developed in order to solve, for example, continuity issues between two energy domains, with the Lagrange multiplier formalism. Another method is given by using a marginalization procedure, in order to either complete an existing evaluation with new covariance or add systematic uncertainty on an experiment described by two theories. The algorithms are well performed along examples, such the 238 U total cross section. The last parts focus on the integral data feedback, using methods of integral data assimilation to reduce the uncertainties on cross sections. This work ends with uncertainty reduction on key nuclear reactions, such the capture and fission cross sections of 238 U and 239 Pu, thanks to PROFIL and PROFIL-2 experiments in Phenix and the Jezebel benchmark. (author) [fr
Resonance analysis and evaluation of the 235U neutron induced cross sections
International Nuclear Information System (INIS)
Leal, L.C.
1990-06-01
Neutron cross sections of fissile nuclei are of considerable interest for the understanding of parameters such as resonance absorption, resonance escape probability, resonance self-shielding,and the dependence of the reactivity on temperature. In the present study, new techniques for the evaluation of the 235 U neutron cross sections are described. The Reich-Moore formalism of the Bayesian computer code SAMMY was used to perform consistent R-matrix multilevel analyses of the selected neutron cross-section data. The Δ 3 -statistics of Dyson and Mehta, along with high-resolution data and the spin-separated fission cross-section data, have provided the possibility of developing a new methodology for the analysis and evaluation of neutron-nucleus cross sections. The results of the analysis consists of a set of resonance parameters which describe the 235 U neutron cross sections up to 500 eV. The set of resonance parameters obtained through a R-matrix analysis are expected to satisfy statistical properties which lead to information on the nuclear structure. The resonance parameters were tested and showed good agreement with the theory. It is expected that the parametrization of the 235 U neutron cross sections obtained in this dissertation represents the current state of art in data as well as in theory and, therefore, can be of direct use in reactor calculations. 44 refs., 21 figs., 8 tabs
Gamma-ray production cross-sections for the interactions of 14.9 MeV neutrons with Si, Cu, Nb and Pb
International Nuclear Information System (INIS)
Fan Guoying
1991-12-01
Gamma rays produced in the interactions of 14.9 MeV neutrons with Si, Cu, Nb and Pb targets were studied. The neutron beam was produced with the T(d,n)He reaction using 300 KeV Cockroft-Walton accelerator. Absolute neutron flux was determined by the associated particle technique. The time-of-flight technique was used to reduce the background. The FWHM of neutron pulses was 1.5 ns. A Ge(Li) detector was used for gamma-ray detection. 39 gamma lines for Si, 39 gamma lines for Cu, 79 for Nb and 39 for Pb were detected. Most of these gamma rays were emitted in (n,γ), (n,n') and (n,2n) reactions. The measurements were made at 40 deg. C, 55 deg. C, 125 deg. C and 140 deg. C relative to the incident neutron beam. The results are presented in the form of the data tables. 9 refs, 11 figs, 19 tabs
Energy Technology Data Exchange (ETDEWEB)
Bernard, B.; Leconte, P.; Gruel, A.; Antony, M.; Di-Salvo, J.; Hudelot, J.P.; Pepino, A.; Lecluze, A. [CEA Cadarache, DEN/CAD/DER/SPRC/LEPh, 13 - Saint-Paul-lez-Durance (France)
2009-07-01
CEA is deeply involved research programs concerning nuclear fuel advanced studies (actinides, plutonium), waste management, the scientific and technical support of French PWR reactors and EPR reactor, and innovative systems. In this framework, specific neutron integral experiments have been carried out in the critical ZPR (zero power reactor) facilities of the CEA at Cadarache such as MINERVE, EOLE and MASURCA. This paper deals with MINERVE Pool Reactor experiments. MINERVE is mainly devoted to neutronics studies of different reactor core types. The aim is to improve the knowledge of the integral absorption cross sections of actinides (OSMOSE program), of new absorbers (OCEAN program) and also for fission Products (CBU program) in thermal, epithermal and fast neutron spectra. (authors)
26Al/sup g,m/ production cross sections from the 23Na(α,n)26Al reaction
International Nuclear Information System (INIS)
Norman, E.B.; Chupp, T.E.; Lesko, K.T.; Schwalbach, P.; Grant, P.J.
1981-01-01
Cross sections have been determined for the production of 26 Al/sup g,m/ from the 23 Na(α,n) reaction. Total 26 Al production cross sections were obtained from measurements of the thick-target neutron yield. 26 Al/sup m/ cross sections were measured using an activation technique. 26 Al/sup g/ cross sections were deduced by subtracting the 26 Al/sup m/ cross sections from the total (α,n) cross sections. The principle of detailed balance has been applied to the low energy data to obtain cross sections for the astrophysically interesting 26 Al/sup g/(n,α 0 ) 23 Na reaction. These results are compared with the results of Hauser-Feshbach calculations
What can be learnt from the channel analysis of the 232Th neutron fission cross section
International Nuclear Information System (INIS)
Abou Yehia, H.; Jary, J.; Trochon, J.; Boldeman, J.W.; Musgrove, A.R. de L.
1979-10-01
Channel analyses of the neutron fission cross section of 232 Th have been made in two laboratories. The calculated fission cross sections and fission fragment anisotropies are compared with the experimental data. Despite some differences in the methods used, the conclusions on the physical aspects of the fission process are very similar
The shell structure effects in neutron cross section calculation by a ...
African Journals Online (AJOL)
The role of the shell structure properties of the nucleus in the calculation of neutron-induced reaction cross-section data based on nuclear reaction theory has been investigated. In this investigation, measured, evaluated and calculated (n.p) reaction cross-section data on la spherical nucleus (i.e. 112Sn) and a deformed ...
Measurements and analysis of the 127I and 129I neutron capture and total cross sections
International Nuclear Information System (INIS)
Noguere, G.
2005-01-01
Most of the experimental work on the interaction of neutrons with matter has focused on materials important to reactor physics and reactor structures. By comparison, the corresponding data for minor actinides or long-lived fission products are poor. A significant demand has developed for improved neutron cross-section data of these little-studied nuclides due to the surge of interest in the transmutation of nuclear waste. With 400 kg of 129 I produced yearly in the reactors of the EU countries and a very long β - half-life of 1.57 x 10 7 years, iodine requires disposal strategies that will isolate this isotope from the environment for long periods of time. Therefore, 129 I is potentially a key long-lived fission product for transmutation applications, since 129 I transmutes in 130 I after a single neutron capture and decays to 130 Xe with a 12.36 h half-life. Accurate capture cross sections would help to reduce uncertainties in waste management concepts. For that purpose, Time-Of-Flight measurements covering the [0.5 eV-100 keV] energy range have been carried out at the 150 MeV pulsed neutron source GELINA of the Institute for Reference Materials and Measurements (IRMM). Two types of experiments have been performed at the IRMM, namely capture and transmission experiments. They are respectively related to the neutron capture and total cross sections. Since the PbI 2 samples used in this work contain natural and radioactive iodine, extensive measurements of 129 I have been carried out under the same experimental conditions as for the 129 I. The data reduction process was performed with the AGS system, and the resonance parameters were extracted with the SAMMY and REFIT shape analysis codes. In a last step, the parameters have been converted into ENDF-6 format and processed with the NJOY code to produce point-wise and multigroup cross sections, as well as MCNP and ERANOS libraries. (author)
Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method
Directory of Open Access Journals (Sweden)
Morel P.
2011-10-01
Full Text Available The measurement of neutron-induced cross sections of short-lived nuclei is extremely difficult due to the radioactivity of the samples. The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. This method presents the advantage that the target material can be stable or less radioactive than the material required for a neutron-induced measurement. We have successfully used the surrogate reaction method to extract neutron-induced fission cross sections of various short-lived actinides. In this work, we investigate whether this technique can be used to determine neutron-induced capture cross sections in the rare-earth region.
Neutron-induced cross sections of short-lived nuclei via the surrogate reaction method
Directory of Open Access Journals (Sweden)
Tassan-Got L.
2012-02-01
Full Text Available The measurement of neutron-induced cross sections of short-lived nuclei is extremely difficult due to the radioactivity of the samples. The surrogate reaction method is an indirect way of determining cross sections for nuclear reactions that proceed through a compound nucleus. This method presents the advantage that the target material can be stable or less radioactive than the material required for a neutron-induced measurement. We have successfully used the surrogate reaction method to extract neutron-induced fission cross sections of various short-lived actinides. In this work, we investigate whether this technique can be used to determine neutron-induced capture cross sections in the rare-earth region.
Measurements of Integral Cross Section Ratios in Two Dosimetry Benchmark Neutron Fields
International Nuclear Information System (INIS)
Fabry, A.; Czock, K.H.
1974-12-01
In the frame of a current interlaboratory effort devoted to the standardization of fuels and materials neutron dosimetry, the 103 Rh(n,n') 103m Rh and 58 Ni(n,p) 58 Co integral cross sections have been accurately measured relatively to the 115 In(n,n') 115m In cross section in the 235 U thermal dission neutron spectrum and in the MOLΣΣ Intermediate-Energy Standard Neutron field. In this last neutron field, the data are related also to the 235 U(n,f) cross section. The measurements are extensively documented and the results briefly compared to literature. Most noticeably, decisive support is provided for the selection of a specific 103 Rh(n,n') 103m Rh differential-energy cross section among the existing, conflicting data. (author)
Measurements of integral cross section ratios in two dosimetry benchmark neutron fields
International Nuclear Information System (INIS)
Fabry, A.; Czock, K.H.
1974-12-01
In the frame of a current interlaboratory effort devoted to the standardization of fuels and materials neutron dosimetry, the 103 Rh(n,n') 103m Rh and 58 Ni(n,p) 58 Co integral cross sections have been accurately measured relatively to the 115 In(n,n') 115m In cross section in the 235 U thermal fission neutron spectrum and in the MOL-ΣΣ intermediate-energy standard neutron field. In this last neutron field, the data are related also to the 235 U(n,f) cross section. The measurements are extensively documented and the results briefly compared to literature. Most noticeably, decisive support is provided for the selection of a specific 103 Rh(n,n') 103m Rh differential-energy cross section among the existing, conflicting data. (author)
International Nuclear Information System (INIS)
Wagner, M.; Vonach, H.
1990-01-01
These proceedings of a specialists' meeting on neutron activation cross sections for fission and fusion energy applications are divided into 4 sessions bearing on: - data needs: 4 conferences - experimental work: 11 conferences - theoretical work: 4 conferences - evaluation work: 5 conferences
Measurements of integral cross section ratios in two dosimetry benchmark neutron fields
Energy Technology Data Exchange (ETDEWEB)
Fabry, A [CEN-SCK, Mol (Belgium); Czock, K H [International Atomic Energy Agency, Laboratory Seibersdorf, Vienna (Austria)
1974-12-01
In the frame of a current interlaboratory effort devoted to the standardization of fuels and materials neutron dosimetry, the {sup 103}Rh(n,n'){sup 103m}Rh and {sup 58}Ni(n,p){sup 58}Co integral cross sections have been accurately measured relatively to the {sup 115}In(n,n'){sup 115m} In cross section in the {sup 235}U thermal fission neutron spectrum and in the MOL-{sigma}{sigma} intermediate-energy standard neutron field. In this last neutron field, the data are related also to the {sup 235}U(n,f) cross section. The measurements are extensively documented and the results briefly compared to literature. Most noticeably, decisive support is provided for the selection of a specific {sup 103}Rh(n,n'){sup 103m}Rh differential-energy cross section among the existing, conflicting data. (author)
Measurements of Integral Cross Section Ratios in Two Dosimetry Benchmark Neutron Fields
Energy Technology Data Exchange (ETDEWEB)
Fabry, A. [CEN-SCK, Mol (Belgium); Czock, K. H. [International Atomic Energy Agency, Vienna (Austria)
1974-12-15
In the frame of a current interlaboratory effort devoted to the standardization of fuels and materials neutron dosimetry, the {sup 103}Rh(n,n'){sup 103m}Rh and {sup 58}Ni(n,p){sup 58}Co integral cross sections have been accurately measured relatively to the {sup 115}In(n,n'){sup 115m}In cross section in the {sup 235}U thermal dission neutron spectrum and in the MOL{Sigma}{Sigma} Intermediate-Energy Standard Neutron field. In this last neutron field, the data are related also to the {sup 235}U(n,f) cross section. The measurements are extensively documented and the results briefly compared to literature. Most noticeably, decisive support is provided for the selection of a specific {sup 103}Rh(n,n'){sup 103m}Rh differential-energy cross section among the existing, conflicting data. (author)
Elastic neutron-proton differential cross section at 647 MeV
International Nuclear Information System (INIS)
Evans, M.L.
1979-04-01
The differential cross section for n-p elastic scattering in the angular range 51 0 was measured with high statistical accuracy using the 647 MeV monoenergetic neutron beam of the Los Alamos Meson Physics Facility. A proton recoil magnetic spectrometer was used for momentum analysis of the charge exchange protons from the reaction n+p→p+n. Absolute normalization of the cross section was established to within 7% using existing cross section data for the reaction p+p→π + +d. The results differ significantly from previous Dubna and PPA cross sections but agree well with recent Saclay data except at extreme backward angles. 41 references
CASTHY, Statistical Model for Neutron Cross-Sections and Gamma-Ray Spectra
International Nuclear Information System (INIS)
Igarasi, Sin-iti; Fukahori, Tokio
1998-01-01
Description of program or function: CASTHY calculates neutron cross sections of total, shape elastic scattering and compound nucleus formation with the optical model, and compound elastic, inelastic and capture cross sections by the statistical model. The other cross sections, such as (n,2n), (n,p), (n,f) reactions are treated as cross sections of competing processes, and their sum is given through input data. Capture gamma-ray spectra can also be calculated. The branching ratio for primary transition can be treated in a particular way, if required
Numerical estimates of multiple reaction corrections in neutron cross-section measurements
International Nuclear Information System (INIS)
Magnusson, G.
1979-04-01
A method to evaluate the effect of secondary neutrons in 14-15 MeV neutron cross-section measurements is presented. The emission spectra of secondary neutrons are calculated by means of the preequilibrium and statistical models. An expression for the collision probability in a homogenous body has been utilized in the calculations. (author)
Analysis of the 239Pu neutron cross sections from 300 to 2000 eV
International Nuclear Information System (INIS)
Derrien, H.; de Saussure, G.
1990-01-01
A recent high-resolution measurement of the neutron fission cross section of 239 Pu has allowed the extension from 1 to 2 keV of a previously reported resonance analysis of the neutron cross sections, and an improvement of the previous analysis in the range 0.3 to 1 keV. This report analyzes this region. 8 refs., 1 fig., 2 tabs
Measurement of total reaction cross sections of exotic neutron rich nuclei
International Nuclear Information System (INIS)
Mittig, W.; Chouvel, J.M.; Wen Long, Z.
1987-01-01
Total reaction cross-sections of neutron rich nuclei from C to Mg in a thick Si-target have been measured using the detection of the associated γ-rays in a 4Π-geometry. This cross-section strongly increases with neutron excess, indicating an increase of as much as 15% of the reduced strong absorption radius with respect to stable nuclei
Calculation of nucleon production cross sections for 200 MeV deuterons
International Nuclear Information System (INIS)
Ridikas, D.; Mittig, W.
1997-01-01
The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick 9 Be, 56 Fe and 238 U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.)
Calculation of nucleon production cross sections for 200 MeV deuterons
Energy Technology Data Exchange (ETDEWEB)
Ridikas, D.; Mittig, W.
1997-12-31
The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick {sup 9}Be, {sup 56}Fe and {sup 238}U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.). 31 refs.
International Nuclear Information System (INIS)
Blink, J.A.; Dye, R.E.; Kimlinger, J.R.
1981-12-01
Calculation of neutron activation of proposed fusion reactors requires a library of neutron-activation cross sections. One such library is ACTL, which is being updated and expanded by Howerton. If the energy-dependent neutron flux is also known as a function of location and time, the buildup and decay of activation products can be calculated. In practice, hand calculation is impractical without energy-averaged cross sections because of the large number of energy groups. A widely used activation computer code, ORIGEN2, also requires energy-averaged cross sections. Accordingly, we wrote the ORLIB code to collapse the ACTL library, using the flux as a weighting function. The ORLIB code runs on the LLNL Cray computer network. We have also modified ORIGEN2 to accept the expanded activation libraries produced by ORLIB
Measurement of neutron total cross-sections for {sup nat}Dy at Pohang Neutron Facility
Energy Technology Data Exchange (ETDEWEB)
Shin, S. G.; Kye, Y. U.; Shvetsov, Valery; Cho, M. H. [POSTECH, Pohang (Korea, Republic of); Namkung, W.; Cho, M. H. [Pohang Accelerator Laboratory, Pohang (Korea, Republic of); Kim, G. N. [Kyungpook National Univ., Daegu (Korea, Republic of); Lee, M. W. [Dongnam Inst. of radiological and Medical Science, Busan (Korea, Republic of)
2013-05-15
There are few measurements for Dy below 100 eV. Moreover, there exist discrepancies among the measurements. In the present work, the total neutron cross-sections for {sup nat}Dy were measured by using the time-of-flight (TOF) method at the Pohang Neutron Facility (PNF). The PNF consists of an electron linac, a water-cooled Ta target, and an 11-m-long TOF path. The characteristics of PNF are described elsewhere. We also briefly discuss the future plan to verify our experimental result. We have measured the total neutron cross-sections of {sup nat}Dy in the neutron energy region from 0.1 eV to 100 eV with the TOF method at the Po hang Neutron Facility. The present result is in good agreement with the previous data and the evaluated data in ENDF/B-VI. We would like to get resonance parameters by using SAMMY or REFIT codes.
International Nuclear Information System (INIS)
Pokotilovskij, Yu.N.; Novopol'tsev, M.I.; Geltenbort, P.; Brenner, T.
2003-01-01
Some results of the test of the time-of-flight neutron spectrometers in the energy range (0.05-2.5)μeV are described. The measurements of total and differential cross sections were performed for several substances relevant to the experiments in the physics of ultracold neutrons: Zr, Al, polyethylene and liquid fluoropolymers
International Nuclear Information System (INIS)
Fukahori, Tokio; Iwamoto, Osamu; Chiba, Satoshi
2003-01-01
For an accelerator-driven nuclear waste transmutation system, it is very important to estimate sub-criticality of core system for feasibility and design study of the system. The fission cross section in the intermediate energy range has an important role. A program FISCAL has been developed to calculate neutron-, proton- and photon-induced fission cross sections in the energy region from several tens of MeV to 3 GeV. FISCAL adopts the systematics considering experimental data for Ag- 243 Am. It is found that unified description of neutron-, proton- and photon-induced fission cross sections is available. (author)
Comparative analysis of the neutron cross-sections of iron from various evaluated data libraries
International Nuclear Information System (INIS)
Bychkov, V.M.; Vozyakov, V.V.; Manokhin, V.N.; Smoll, F.; Resner, P.; Seeliger, D.; Hermsdorf, D.
1983-09-01
The comparative analysis of neutron cross-sections of iron from evaluated nuclear data libraries SOKRATOR, KEDAK, ENDL is done in energy interval from 0.025 eV to 20 MeV. Some of iron cross-sections from SOKRATOR library are revised and new data, which are obtained by using new experimental data and more comprehensive theoretical methods, are recommended. As a result the new version of the iron neutron cross-section file (BNF-2012) is produced for SOKRATOR library. (author)
Neutron total and scattering cross sections of 6Li in the few MeV region
International Nuclear Information System (INIS)
Smith, A.; Guenther, P.; Whalen, J.
1980-02-01
Neutron total cross sections of 6 Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of approx. 10 scattering angles and at incident-neutron intervals of approx.< 100 keV. Neutron differential inelastic-scattering cross sections are measured in the incident-energy range 3.5 to 4.0 MeV. The experimental results are extended to lower energies using measured neutron total cross sections recently reported elsewhere by the authors. The composite experimental data (total cross sections from 0.1 to 4.8 MeV and scattering cross sections from 0.22 to 4.0 MeV) are interpreted in terms of a simple two-level R-matrix model which describes the observed cross sections and implies the reaction cross section in unobserved channels; notably the (n;α)t reaction (Q = 4.783 MeV). The experimental and calculational results are compared with previously reported results as summarized in the ENDF/B-V evaluated nuclear data file
The importance of fast neutron scattering cross sections for neutron dosimetry in soft tissues
International Nuclear Information System (INIS)
Jahr, R.; Brede, H.J.
1979-05-01
Tissue equivalent plastic materials are used for the construction of accurate neutron dosemeters. As compared to real tissue, in materials most of the oxygen content is replaced by carbon. In order to determine the dose to human tissue a kerma correction factor has to be used. It is shown that the uncertainty (corresponding to 1 delta) of the correction factor at E = 14.5 MeV amounts to at least 5.2%. An important contribution to the uncertainties results from the lack of experimental data of the 12 C(n, n' 3α), 16 O(n,n'p) and 16 O(n,n'α)-cross-sections. These data are to be calculated by subtracting all other cross sections from the total cross section of ( 16 O + n) and ( 12 C + n). It is shown that the uncertainties of the kerma correction factor can be considerably reduced by an accurate measurement of the scattering cross sections of carbon and oxygen. (orig.) [de
Measurement, calculation and evaluation of photon production cross-sections
International Nuclear Information System (INIS)
Kocherov, N.P.
1990-03-01
The IAEA Specialists' Meeting on Measurement, Calculation and Evaluation of Photon Production Cross-Sections was held in Smolenice, Czechoslovakia, 5-7 February 1990. The meeting was hosted by the Institute of Physics of the Electro-Physical Research Centre, Slovak Academy of Sciences, Bratislava. This report contains the conclusions and recommendations of this meeting. The papers which the participants have presented at the meeting will be published as an INDC Report. (author)
Some remarks on the neutron elastic- and enelastic-scattering cross sections of palladium
International Nuclear Information System (INIS)
Chiba, S.; Guenther, P.T.; Smith, A.B.
1989-05-01
The cross sections for the elastic-scattering of 5.9, 7.1 and 8.0 MeV neutrons from elemental palladium were measured at forty scattering angles distributed between ∼15/degree/ and 160/degree/. The inelastic-scattering cross sections for the excitation of palladium levels at energies of 260 keV to 560 keV were measured with high resolution at the same energies, and at a scattering angle of 80/degree/. The experimental results were combined with lower-energy values previously obtained by this group to provide a comprehensive data base extending from near the inelastic-scattering threshold to 8 MeV. That data base was interpreted in terms of a coupled-channel model, including the inelastic excitation of one- and two-phonon vibrational levels of the even isotopes of palladium. It was concluded that the palladium inelastic-scattering cross section, at the low energies of interest in assessment of fast-fission-reactor performance, are large (∼50% greater than given in widely used evaluated fission-product data files). They primarily involve compound-nucleus processes, with only a small direct-reaction component attributable to the excitation of the one-phonon, 2 + , vibrational levels of the even isotopes of palladium. 24 refs., 6 figs
Extensive set of low-fidelity cross sections covariances in fast neutron region
International Nuclear Information System (INIS)
Pigni, M.T.; Herman, M.; Oblozinsky, P.
2008-01-01
We produced a large set of neutron cross section covariances in the energy range of 5 keV - 20 MeV. The covariance matrices were calculated for 307 isotopes divided into three major regions: structural materials, fission products, and heavy nuclei. These results have been developed to provide initial, but consistent estimates of covariance data for nuclear criticality safety applications. The methodology for the determination of such covariance matrices is presented. It combines the nuclear reaction model code EMPIRE which calculates sensitivity of cross sections to nuclear reaction model parameters, and the Bayesian code KALMAN that propagates uncertainties of the model parameters to cross sections. Taking into account large number of materials, only marginal reference to experimental data was made. The covariances were derived from the perturbation of several key model parameters selected by the sensitivity analysis. These parameters refer to the optical model potential, the level densities and the strength of the pre-equilibrium emission. This work represents the first try ever to generate nuclear data covariances on such a large scale. (authors)
Molecular dynamical and structural studies for the bakelite by neutron cross section measurements
International Nuclear Information System (INIS)
Voi, D.L.
1992-05-01
Neutron reaction cross sections were determined by transmission and scattering measurements, to study the dynamics and molecular structure of calcined bakelites. Total cross sections were determined, with a deviation smaller than 5%, from the literature values, by neutron transmission method and a specially devised approximation. These cross sections were then correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. Double differential scattering cross sections, scattering law values and frequency distributions were determined with 15% error using the neutron inelastic scattering method. The frequency distributions as well as the overall results from all experimental techniques used in this work allowed to suggest a structural model like polycyclic hydrocarbons, for calcined bakelite at 800 0 C. (author)
Energy Technology Data Exchange (ETDEWEB)
Smith, D.L.
1987-11-01
Ratio measurements are routinely employed in studies of neutron interaction processes in order to generate new differential cross-section data or to test existing differential cross-section information through examination of the corresponding response in integral neutron spectra. Interpretation of such data requires that careful attention be given to details of the neutron spectra involved in these measurements. Two specific tasks are undertaken in the present investigation: (1) Using perturbation theory, a formula is derived which permits one to relate the ratio measured in a realistic quasimonoenergetic spectrum to the desired pure monoenergetic ratio. This expression involves only the lowest-order moments of the neutron energy distribution and corresponding parameters which serve to characterize the energy dependence of the differential cross sections, quantities which can generally be estimated with reasonable precision from the uncorrected data or from auxiliary information. (2) Using covariance methods, a general formalism is developed for calculating the uncertainty of a measured integral cross-section ratio which involves an arbitrary neutron spectrum. This formalism is employed to further examine the conditions which influence the sensitivity of such measured ratios to details of the neutron spectra and to their uncertainties. Several numerical examples are presented in this report in order to illustrate these principles, and some general conclusion are drawn concerning the development and testing of neutron cross-section data by means of ratio experiments. 16 refs., 1 fig., 4 tabs.
International Nuclear Information System (INIS)
Smith, D.L.
1987-11-01
Ratio measurements are routinely employed in studies of neutron interaction processes in order to generate new differential cross-section data or to test existing differential cross-section information through examination of the corresponding response in integral neutron spectra. Interpretation of such data requires that careful attention be given to details of the neutron spectra involved in these measurements. Two specific tasks are undertaken in the present investigation: (1) Using perturbation theory, a formula is derived which permits one to relate the ratio measured in a realistic quasimonoenergetic spectrum to the desired pure monoenergetic ratio. This expression involves only the lowest-order moments of the neutron energy distribution and corresponding parameters which serve to characterize the energy dependence of the differential cross sections, quantities which can generally be estimated with reasonable precision from the uncorrected data or from auxiliary information. (2) Using covariance methods, a general formalism is developed for calculating the uncertainty of a measured integral cross-section ratio which involves an arbitrary neutron spectrum. This formalism is employed to further examine the conditions which influence the sensitivity of such measured ratios to details of the neutron spectra and to their uncertainties. Several numerical examples are presented in this report in order to illustrate these principles, and some general conclusion are drawn concerning the development and testing of neutron cross-section data by means of ratio experiments. 16 refs., 1 fig., 4 tabs
International Nuclear Information System (INIS)
Ilieva, K.; Belousov, S.; Apostolov, T.
1998-01-01
The verification of calculated neutron fluence onto the WWER-440/230 pressure vessel is very topical task in particular referring that some of this type of reactors have been operated the major part of its design lifetime. Since the induced activity from the neutron irradiation onto the elements is a simple response of neutron flux the neutron fluence verification usually is done using the measured activity of radionuclides produced during reactor operation. Calculational and experimental results of 54 Mn induced activity of scraps from inner wall of Unit 1 reactor pressure vessel after 18th cycle and detectors irradiated behind the vessel during the 18th cycle of Unit 1 at Kozloduy NPP as well as neutron flux attenuation through the WWER-440/230 pressure vessel are presented. Neutron cross sections libraries generated on the base of ENDF/B-IV and ENDF/B-VI have been used in the calculations. The comparative analysis of evaluated activities and attenuation coefficient demonstrates the better reliability of the neutron fluence calculations by the libraries based on ENDF/B-VI than by ones on ENDF/B-IV. The extreme rarity of data for the activity of scraps from the WWER-440 reactor vessel and its combination with the data for the detectors irradiated behind the vessel makes them especially attractive for verification of calculational methods of neutron fluence onto the WWER-440 vessel with dummy cassettes loading. (author)
Isospin dependent Boltzmann-langevin equation and the production cross section of 19Na
International Nuclear Information System (INIS)
Ming Zhaoyu; Zhang Fengshou; Chen Liewen; Zhu Zhiyuan; Zhang Wenlong; Guo Zhongyan; Xiao Guoqing
2000-01-01
A new transport model (isospin dependent Boltzmann-Langevin equation) is developed and it is shown that this model can regenerate the experimental data for reaction of 12 C + 12 C at 28.7 MeV/u. The production cross section of 19 Na is systematically studied for reactions of 17-20,22 Ne + 12 C at 28.7 MeV/u. It is found that a neutron deficient projectile has larger 19 Na cross section than a stable projectile
International Nuclear Information System (INIS)
Alsmiller, R.G. Jr.; Barnes, J.M.; Drischler, J.D.
1986-02-01
Multigroup cross sections (66 neutron groups and 22 photon groups) are described for neutron energies from thermal to 400 MeV. The elements considered are hydrogen, 10 B, 11 B, carbon, nitrogen, oxygen, sodium, magnesium, aluminum, silicon, sulfur, potassium, calcium, chromium, iron, nickel, tungsten, and lead. The cross section data presented are a revision of similar data presented previously. In the case of iron, transport calculations using the earlier and the revised cross sections are presented and compared, and significant differences are found. The revised cross sections are available from the Radiation Shielding information Center of the Oak Ridge National Laboratory. 32 refs., 5 figs., 3 tabs
Measurement of the neutron total cross section of sodium
International Nuclear Information System (INIS)
Larson, D.C.; Harvey, J.A.; Hill, M.W.
1976-01-01
The transmission of neutrons through a sample of pure sodium was measured in the energy range 40 keV to 20 MeV. The measurement points out several areas for improvement in the sodium evaluation for ENDF/B-V, the most important being the broadening of the minimum at 300 keV
Semiclassical model of cross section for fast neutrons
International Nuclear Information System (INIS)
Rosato, A.; D'Oliveira, A.A.
1977-01-01
A study for main aspects of fast neutron scattering is presented and, a semiclassical approximation applying to several pratic cases is described. The obtained results are compared with experimental data for deformed nuclei, and, with theoretical data based on optical model without treatment of deformations. (M.C.K.) [pt
Fission neutron spectrum averaged cross sections for threshold reactions on arsenic
International Nuclear Information System (INIS)
Dorval, E.L.; Arribere, M.A.; Kestelman, A.J.; Comision Nacional de Energia Atomica, Cuyo Nacional Univ., Bariloche; Ribeiro Guevara, S.; Cohen, I.M.; Ohaco, R.A.; Segovia, M.S.; Yunes, A.N.; Arrondo, M.; Comision Nacional de Energia Atomica, Buenos Aires
2006-01-01
We have measured the cross sections, averaged over a 235 U fission neutron spectrum, for the two high threshold reactions: 75 As(n,p) 75 mGe and 75 As(n,2n) 74 As. The measured averaged cross sections are 0.292±0.022 mb, referred to the 3.95±0.20 mb standard for the 27 Al(n,p) 27 Mg averaged cross section, and 0.371±0.032 mb referred to the 111±3 mb standard for the 58 Ni(n,p) 58m+g Co averaged cross section, respectively. The measured averaged cross sections were also evaluated semi-empirically by numerically integrating experimental differential cross section data extracted for both reactions from the current literature. The calculations were performed for four different representations of the thermal-neutron-induced 235 U fission neutron spectrum. The calculated cross sections, though depending on analytical representation of the flux, agree with the measured values within the estimated uncertainties. (author)
Directory of Open Access Journals (Sweden)
О. О. Gritzay
2016-12-01
Full Text Available Development of the technique for determination of the total neutron cross sections from the measurements of sample transmission by filtered neutrons, scattered on hydrogen is described. One of the methods of the transmission determination TH52Cr from the measurements of 52Cr sample, using average energy shift method for filtered neutron beam is presented. Using two methods of the experimental data processing, one of which is presented in this paper (another in [1], there is presented a set of transmissions, obtained for different samples and for different measurement angles. Two methods are fundamentally different; therefore, we can consider the obtained processing results, using these methods as independent. In future, obtained set of transmissions is planned to be used for determination of the parameters E0, Гn and R/ of the resonance 52Cr at the energy of 50 keV.
Anomalous neutron Compton scattering cross section in zirconium hydride
International Nuclear Information System (INIS)
Abdul-Redah, T.; Krzystyniak, M.; Mayers, J.; Chatzidimitriou-Dreismann, C.A.
2005-01-01
In the last few years we observed a shortfall of intensity of neutrons scattered from protons in various materials including metal hydrogen systems using neutron Compton scattering (NCS) on the VESUVIO instrument (ISIS, UK). This anomaly has been attributed to the existence of short-lived quantum entangled states of protons in these materials. Here we report on results of very recent NCS measurements on ZrH 2 at room temperature. Also here an anomalous shortfall of scattering intensity due to protons is observed. In contrast to previous experiments on NbH 0.8 , the anomalies found in ZrH 2 are independent of the scattering angle (or momentum transfer). These different results are discussed in the light of recent criticisms and experimental tests related to the data analysis procedure on VESUVIO
Neutron cross-sections database for amino acids and proteins analysis
Energy Technology Data Exchange (ETDEWEB)
Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin, E-mail: dante@ien.gov.br, E-mail: fferreira@ien.gov.br, E-mail: Chaffin@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Rocha, Helio F. da, E-mail: hrocha@gbl.com.br [Universidade Federal do Rio de Janeiro (IPPMG/UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Pediatria
2015-07-01
Biological materials may be studied using neutrons as an unconventional tool of analysis. Dynamics and structures data can be obtained for amino acids, protein and others cellular components by neutron cross sections determinations especially for applications in nuclear purity and conformation analysis. The instrument used for this is the crystal spectrometer of the Instituto de Engenharia Nuclear (IEN-CNEN-RJ), the only one in Latin America that uses neutrons for this type of analyzes and it is installed in one of the reactor Argonauta irradiation channels. The experimentally values obtained are compared with calculated values using literature data with a rigorous analysis of the chemical composition, conformation and molecular structure analysis of the materials. A neutron cross-section database was constructed to assist in determining molecular dynamic, structure and formulae of biological materials. The database contains neutron cross-sections values of all amino acids, chemical elements, molecular groups, auxiliary radicals, as well as values of constants and parameters necessary for the analysis. An unprecedented analytical procedure was developed using the neutron cross section parceling and grouping method for data manipulation. This database is a result of measurements obtained from twenty amino acids that were provided by different manufactories and are used in oral administration in hospital individuals for nutritional applications. It was also constructed a small data file of compounds with different molecular groups including carbon, nitrogen, sulfur and oxygen, all linked to hydrogen atoms. A review of global and national scene in the acquisition of neutron cross sections data, the formation of libraries and the application of neutrons for analyzing biological materials is presented. This database has further application in protein analysis and the neutron cross-section from the insulin was estimated. (author)
Neutron cross-sections database for amino acids and proteins analysis
International Nuclear Information System (INIS)
Voi, Dante L.; Ferreira, Francisco de O.; Nunes, Rogerio Chaffin; Rocha, Helio F. da
2015-01-01
Biological materials may be studied using neutrons as an unconventional tool of analysis. Dynamics and structures data can be obtained for amino acids, protein and others cellular components by neutron cross sections determinations especially for applications in nuclear purity and conformation analysis. The instrument used for this is the crystal spectrometer of the Instituto de Engenharia Nuclear (IEN-CNEN-RJ), the only one in Latin America that uses neutrons for this type of analyzes and it is installed in one of the reactor Argonauta irradiation channels. The experimentally values obtained are compared with calculated values using literature data with a rigorous analysis of the chemical composition, conformation and molecular structure analysis of the materials. A neutron cross-section database was constructed to assist in determining molecular dynamic, structure and formulae of biological materials. The database contains neutron cross-sections values of all amino acids, chemical elements, molecular groups, auxiliary radicals, as well as values of constants and parameters necessary for the analysis. An unprecedented analytical procedure was developed using the neutron cross section parceling and grouping method for data manipulation. This database is a result of measurements obtained from twenty amino acids that were provided by different manufactories and are used in oral administration in hospital individuals for nutritional applications. It was also constructed a small data file of compounds with different molecular groups including carbon, nitrogen, sulfur and oxygen, all linked to hydrogen atoms. A review of global and national scene in the acquisition of neutron cross sections data, the formation of libraries and the application of neutrons for analyzing biological materials is presented. This database has further application in protein analysis and the neutron cross-section from the insulin was estimated. (author)
Energy Technology Data Exchange (ETDEWEB)
Kerveno, M
2000-09-27
In order to develop new options for nuclear waste management, studies are carrying out on the perfecting of hybrid systems (sub-critical reactor driven by accelerator). This thesis work takes place more precisely in the framework of nuclear data linked to hybrid systems development. Increasing the upper limit energy value (from 20 to 150 MeV) of data bases supposes that theoretical codes could have sufficient predictive power in this energy range. Thus it's necessary to measure new cross sections to constrain these codes. The experiment, performed at Louvain-la-Neuve Cyclotron, aims to determine the double differential cross sections for light charged particles production in neutron induced reactions at 62.7 MeV on natural lead target. The detection device consists of 6 NE102-CsI telescopes. Time of flight measurements are used to reconstruct the neutron energy spectra. The general framework (hybrid systems and associated nuclear data problematic) in which this work takes place is presented in a first part. The experimental set up used for our measurements is described in a second part. The three following parts are dedicated to the data analysis and double differential cross sections extraction. The particle discrimination, the energy calibration of detectors as the different corrections applied to the experimental spectra are related in details. And finally a comparative study between our experimental results and some theoretical predictions is presented. (author)
Energy Technology Data Exchange (ETDEWEB)
Kerveno, M
2000-09-27
In order to develop new options for nuclear waste management, studies are carrying out on the perfecting of hybrid systems (sub-critical reactor driven by accelerator). This thesis work takes place more precisely in the framework of nuclear data linked to hybrid systems development. Increasing the upper limit energy value (from 20 to 150 MeV) of data bases supposes that theoretical codes could have sufficient predictive power in this energy range. Thus it's necessary to measure new cross sections to constrain these codes. The experiment, performed at Louvain-la-Neuve Cyclotron, aims to determine the double differential cross sections for light charged particles production in neutron induced reactions at 62.7 MeV on natural lead target. The detection device consists of 6 NE102-CsI telescopes. Time of flight measurements are used to reconstruct the neutron energy spectra. The general framework (hybrid systems and associated nuclear data problematic) in which this work takes place is presented in a first part. The experimental set up used for our measurements is described in a second part. The three following parts are dedicated to the data analysis and double differential cross sections extraction. The particle discrimination, the energy calibration of detectors as the different corrections applied to the experimental spectra are related in details. And finally a comparative study between our experimental results and some theoretical predictions is presented. (author)
Filtered thermal neutron captured cross sections measurements and decay heat calculations
International Nuclear Information System (INIS)
Pham Ngoc Son; Vuong Huu Tan
2015-01-01
Recently, a pure thermal neutron beam has been developed for neutron capture measurements based on the horizontal channel No.2 of the research reactor at the Nuclear Research Institute, Dalat. The original reactor neutron spectrum is transmitted through an optimal composition of Bi and Si single crystals for delivering a thermal neutron beam with Cadmium ratio (R ed ) of 420 and neutron flux (Φ th ) of 1.6*10 6 n/cm 2 .s. This thermal neutron beam has been applied for measurements of capture cross sections for nuclide of 51 V, by the activation method relative to the standard reaction 197 Au(n,γ) 198 Au. In addition to the activities of neutron capture cross sections measurements, the study on nuclear decay heat calculations has been also considered to be developed at the Institute. Some results on calculation procedure and decay heat values calculated with update nuclear database for 235 U are introduced in this report. (author)
Expected anomalies of the neutron cross section near the liquid-glass transition
International Nuclear Information System (INIS)
Gotze, W.
1987-01-01
In the frameworks of a microscopic theory the anomalies of the neutron cross section near the liquid-glass transition are discussed. The central concept of the theory is the correlation function for density fluctuations of wave vector q and frequency ω. Its absorptive part is proportional to the dynamical structure factor S(q, ω), this is the scattering law for coherent neutron scattering. Tagged particle motion is evaluated as well and it yields the incoherent neutron scattering cross section S i (q, ω) in. The predictions of the theory for S(q, ω) and Si (q, ω) a q-ω domain are given
Amino acids analysis using grouping and parceling of neutrons cross sections techniques
International Nuclear Information System (INIS)
Voi, Dante Luiz Voi; Rocha, Helio Fenandes da
2002-01-01
Amino acids used in parenteral administration in hospital patients with special importance in nutritional applications were analyzed to compare with the manufactory data. Individual amino acid samples of phenylalanine, cysteine, methionine, tyrosine and threonine were measured with the neutron crystal spectrometer installed at the J-9 irradiation channel of the 1 kW Argonaut Reactor of the Instituto de Engenharia Nuclear (IEN). Gold and D 2 O high purity samples were used for the experimental system calibration. Neutron cross section values were calculated from chemical composition, conformation and molecular structure analysis of the materials. Literature data were manipulated by parceling and grouping neutron cross sections. (author)
International Nuclear Information System (INIS)
Holden, N.E.
1994-01-01
A re-evaluation of all thermal neutron cross sections and neutron resonance integrals has been performed, utilizing the previous database of the ''Barn Book'' and all of the more recently published experiments. Only significant changes or previously undetermined values are recorded in this report. The source for each value is also recorded in the accompanying table
High-energy Neutron-induced Fission Cross Sections of Natural Lead and Bismuth-209
Tarrio, D; Carrapico, C; Eleftheriadis, C; Leeb, H; Calvino, F; Herrera-Martinez, A; Savvidis, I; Vlachoudis, V; Haas, B; Koehler, P; Vannini, G; Oshima, M; Le Naour, C; Gramegna, F; Wiescher, M; Pigni, M T; Audouin, L; Mengoni, A; Quesada, J; Becvar, F; Plag, R; Cennini, P; Mosconi, M; Rauscher, T; Couture, A; Capote, R; Sarchiapone, L; Vlastou, R; Domingo-Pardo, C; Dillmann, I; Pavlopoulos, P; Karamanis, D; Krticka, M; Jericha, E; Ferrari, A; Martinez, T; Trubert, D; Oberhummer, H; Karadimos, D; Plompen, A; Isaev, S; Terlizzi, R; Cortes, G; Cox, J; Cano-Ott, D; Pretel, C; Colonna, N; Berthoumieux, E; Vaz, P; Heil, M; Lopes, I; Lampoudis, C; Walter, S; Calviani, M; Gonzalez-Romero, E; Embid-Segura, M; Stephan, C; Igashira, M; Papachristodoulou, C; Aerts, G; Tavora, L; Berthier, B; Rudolf, G; Andrzejewski, J; Villamarin, D; Ferreira-Marques, R; Tain, J L; O'Brien, S; Reifarth, R; Kadi, Y; Neves, F; Poch, A; Kerveno, M; Rubbia, C; Lazano, M; Dahlfors, M; Wisshak, K; Salgado, J; Dridi, W; Ventura, A; Andriamonje, S; Assimakopoulos, P; Santos, C; Voss, F; Ferrant, L; Patronis, N; Chiaveri, E; Guerrero, C; Perrot, L; Vicente, M C; Lindote, A; Praena, J; Baumann, P; Kappeler, F; Rullhusen, P; Furman, W; David, S; Marrone, S; Tassan-Got, L; Gunsig, F; Alvarez-Velarde, F; Massimi, C; Mastinu, P; Pancin, J; Papadopoulos, C; Tagliente, G; Haight, R; Chepel, V; Kossionides, E; Badurek, G; Marganiec, J; Lukic, S; Pavlik, A; Goncalves, I; Duran, I; Alvarez, H; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C
2011-01-01
The CERN Neutron Time-Of-Flight (n\\_TOF) facility is well suited to measure small neutron-induced fission cross sections, as those of subactinides. The cross section ratios of (nat)Pb and (209)Bi relative to (235)U and (238)U were measured using PPAC detectors. The fragment coincidence method allows to unambiguously identify the fission events. The present experiment provides the first results for neutron-induced fission up to 1 GeV for (nat)Pb and (209)Bi. A good agreement with previous experimental data below 200 MeV is shown. The comparison with proton-induced fission indicates that the limiting regime where neutron-induced and proton-induced fission reach equal cross section is close to 1 GeV.
International Nuclear Information System (INIS)
Ivascu, M.
1983-10-01
Computer codes incorporating advanced nuclear models (optical, statistical and pre-equilibrium decay nuclear reaction models) were used to calculate neutron cross sections needed for fusion reactor technology. The elastic and inelastic scattering (n,2n), (n,p), (n,n'p), (n,d) and (n,γ) cross sections for stable molybdenum isotopes Mosup(92,94,95,96,97,98,100) and incident neutron energy from about 100 keV or a threshold to 20 MeV were calculated using the consistent set of input parameters. The hydrogen production cross section which determined the radiation damage in structural materials of fusion reactors can be simply deduced from the presented results. The more elaborated microscopic models of nuclear level density are required for high accuracy calculations
Monte Carlo calculation of the cross-section of single event upset induced by 14MeV neutrons
International Nuclear Information System (INIS)
Li, H.; Deng, J.Y.; Chang, D.M.
2005-01-01
High-density static random access memory may experience single event upsets (SEU) in neutron environments. We present a new method to calculate the SEU cross-section. Our method is based on explicit generation and transport of the secondary reaction products and detailed accounting for energy loss by ionization. Instead of simulating the behavior of the circuit, we use the Monte Carlo method to simulate the process of energy deposition in sensitive volumes. Thus, we do not need to know details about the circuit. We only need a reasonable guess for the size of the sensitive volumes. In the Monte Carlo simulation, the cross-section of SEU induced by 14MeV neutrons is calculated. We can see that the Monte Carlo simulation not only can provide a new method to calculate SEU cross-section, but also can give a detailed description about random process of the SEU
International Nuclear Information System (INIS)
Pavlik, A.; Vonach, H.; Hitzenberger-Schauer, H.; Chadwick, M.B.; Nelson, R.O.; Haight, R.C.; Wender, S.A.; Young, P.G.
1999-01-01
The prompt γ-radiation from the interaction of fast neutrons with samples of Al and enriched 208 Pb was measured using the white neutron beam of the LANSCE/WNR facility at the Los Alamos National Laboratory. From the aluminum γ-ray spectra excitation functions for prominent γ-ray transitions in various residual nuclei (in the range from F to Al) were determined for neutron energies up to 400 MeV. In addition to the primary purpose of the 208 Pb experiment, the study of (n,xnγ) reactions leading to various lead isotopes. γ-ray transitions in residual Tl nuclei were analyzed and cross sections were derived in the neutron energy range from the effective threshold to 200 MeV. In the neutron energy range up to 200 MeV all experimental results were compared with nuclear model calculations using the code GNASH. (author)
Surrogate Measurements of Actinide (n,2n) Cross Sections with NeutronSTARS
Energy Technology Data Exchange (ETDEWEB)
Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, R. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Akindele, O. A. [Univ. of California, Berkeley, CA (United States); Koglin, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wang, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tamashiro, A. [Oregon State Univ., Corvallis, OR (United States)
2016-09-27
Directly measuring (n,2n) cross sections on short-lived actinides presents a number of experimental challenges. The surrogate reaction technique is an experimental method for measuring cross sections on short-lived isotopes, and it provides a unique solution for measuring (n,2n) cross sections. This technique involves measuring a charged-particle reaction cross section, where the reaction populates the same compound nucleus as the reaction of interest. To perform these surrogate (n,2n) cross section measurements, a silicon telescope array has been placed along a beam line at the Texas A&M University Cyclotron Institute, which is surrounded by a large tank of gadolinium-doped liquid scintillator, which acts as a neutron detector. The combination of the charge-particle and neutron-detector arrays is referred to as NeutronSTARS. In the analysis procedure for calculating the (n,2n) cross section, the neutron detection efficiency and time structure plays an important role. Due to the lack of availability of isotropic, mono-energetic neutron sources, modeling is an important component in establishing this efficiency and time structure. This report describes the NeutronSTARS array, which was designed and commissioned during this project. It also describes the surrogate reaction technique, specifically referencing a ^{235}U(n,2n) commissioning measurement that was fielded during the past year. Advanced multiplicity analysis techniques have been developed for this work, which should allow for efficient analysis of ^{241}Pu(n,2n) and ^{239}Pu(n,2n) cross section measurements
Measurements of the effective thermal neutron absorption cross-section in multi-grain models
International Nuclear Information System (INIS)
Drozdowicz, K.; Gabanska, B.; Igielski, A.; Krynicka, E.; Schneider, K.; Woznicka, U.
2005-01-01
The effective macroscopic absorption cross-section Σ a eff of thermal neutrons in a grained medium differs from the corresponding cross-section Σ a hom in the homogeneous medium consisting of the same components, contributing in the same amounts. The ratio of these cross-sections defines the grain parameter, G, which is a measure of heterogeneity of the system for neutron absorption. Heterogeneous models have been built as two- or three-component systems (Ag, Cu and Co 3 O 4 grains distributed in a regular grid in Plexiglas, in various proportions between them). The effective absorption cross-section has been measured and the experimental grain parameter has been found for each model. The obtained values are in the interval 0.34 < G < 0.58, while G = 1 means the homogeneous material. (author)
Total cross section measurement of radioactive isotopes with a thin beam neutron spectrometer
International Nuclear Information System (INIS)
Razbudej, V.F.; Vertebnyj, V.P.; Padun, G.S.; Muravitskij, A.V.
1975-01-01
The method for measuring the neutron total cross sections of radioactive isotopes by a time-of-flight spectrometer with a narrow (0.17 mm in diameter) beam of thermal neutrons is described. The distinguishing feature of this method is the use of capillary samples with a small amount of substance (0.05-1.0 mg). The energy range is 0.01-0.3 eV. The total cross sections of irradiated samples of sub(153)Eu and sub(151)Eu are measured. From them are obtained the cross sections of sub(152)Eu (Tsub(1/2)=12.4 g) and of sub(154)E (Tsub(1/2)=8.6 yr); they equal 11400+-1400 and 1530+-190 barn at E=0.0253 eV. The cross section of the sub(152)Eu absorption for the thermal spectrum (T=333 K) is determined by the activation method; it is 8900+-1200 barn
Formalism for neutron cross section covariances in the resonance region using kernel approximation
Energy Technology Data Exchange (ETDEWEB)
Oblozinsky, P.; Cho,Y-S.; Matoon,C.M.; Mughabghab,S.F.
2010-04-09
We describe analytical formalism for estimating neutron radiative capture and elastic scattering cross section covariances in the resolved resonance region. We use capture and scattering kernels as the starting point and show how to get average cross sections in broader energy bins, derive analytical expressions for cross section sensitivities, and deduce cross section covariances from the resonance parameter uncertainties in the recently published Atlas of Neutron Resonances. The formalism elucidates the role of resonance parameter correlations which become important if several strong resonances are located in one energy group. Importance of potential scattering uncertainty as well as correlation between potential scattering and resonance scattering is also examined. Practical application of the formalism is illustrated on {sup 55}Mn(n,{gamma}) and {sup 55}Mn(n,el).
Effect of γ-ray emission on transuranium element production cross sections in heavy ion reactions
International Nuclear Information System (INIS)
Il'inov, A.S.; Oganesyan, Yu.Ts.; Cherepanov, E.A.
1980-01-01
The effect of competition of the γ ray emission with neutron evaporation and of compound nuclei fission induced by heavy ion reactions on the production cross sections for transuranium elements is considered. It is shown that taking account of γ ray emission leads to the broadening of the excitation functions of the (HI, xny) reactions such as 18 O+ 238 U, 40 Ar+ 206 Pb, 40 Ar+ 207 Pb and 40 Ar+ 208 Pb reactions and to the displacement of their maximum toward the higher energies as well as to an increase of the absolute cross sections which is especially strong close to the fusion barrier. Cross sections for the radiative capture of heavy ions by a heavy target nucleus in 40 Ar+ 206 Pb, 40 Ar+ 208 Pb, 48 Ca+ 204 Pb and 48 Ca+ 208 Pb reactions are estimated
Bound coherent and incoherent thermal neutron scattering cross sections of the elements
International Nuclear Information System (INIS)
Sears, V.F.
1982-12-01
An up-to-date table of bound coherent and incoherent thermal neutron scattering cross sections of the elements is presented. Values from two different data sources are calculated and compared. These sources are: (1) the free-atom cross sections listed in the Σbarn bookΣ and (2) the Julich scattering length tables. We also call attention to, and clarify, the confusion that exists in the literature concerning the sign of the imaginary part of the complex scattering length
Thermal-neutron fission cross section of 26. 1-min /sup 235/U/sup m/
Energy Technology Data Exchange (ETDEWEB)
Talbert W.L. Jr.; Starner, J.W.; Estep, R.J.; Balestrini, S.J.; Attrep M. Jr.; Efurd, D.W.; Roensch, F.R.
1987-11-01
The thermal-neutron fission cross section of /sup 235/U/sup m/ has been measured relative to the ground-state cross section. A rapid radiochemical separation procedure was developed to provide sizeable (10/sup 10/ to 10/sup 11/ atom) samples that were reasonably free of the parent /sup 239/Pu. From a series of eight measurements, the value of 1.42 +- 0.04 was obtained for the ratio sigma/sub m//sigma/sub g/.
DEFF Research Database (Denmark)
Lindgård, Per-Anker; Kowalska, A.; Laut, Peter
1967-01-01
curves are suggested. The magnon cross section for unpolarized neutrons is calculated and shown to be dependent on the anisotropy in the spin interaction. Thus in principle it allows the detection of anisotropy in the exchange interaction. Some remarks are made concerning antiferromagnetic and plane...... for the exchange interaction seem to be necessary for agreement with experimental dispersion curves be obtained. The effect of the anisotropy in the cross section is estimated and shown to be important for small magnon energies....
Integral test on activation cross section of tag gas nuclides using fast neutron spectrum fields
Energy Technology Data Exchange (ETDEWEB)
Aoyama, Takafumi; Suzuki, Soju [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center
1997-03-01
Activation cross sections of tag gas nuclides, which will be used for the failed fuel detection and location in FBR plants, were evaluated by the irradiation tests in the fast neutron spectrum fields in JOYO and YAYOI. The comparison of their measured radioactivities and the calculated values using the JENDL-3.2 cross section set showed that the C/E values ranged from 0.8 to 2.8 for the calibration tests in YAYOI and that the present accuracies of these cross sections were confirmed. (author)
R-matrix analysis of the /sup 239/Pu neutron cross sections
Energy Technology Data Exchange (ETDEWEB)
Saussure, G. de; Perez, R.B.; Macklin, R.L.
1986-03-01
/sup 239/Pu neutron cross-section data in the resolved resonance region were analyzed with the R-Matrix Bayesian Program SAMMY. Below 30 eV the cross sections computed with the multilevel parameters are consistent with recent fission and transmission measurements as well as with older capture and alpha measurements. Above 30 eV no suitable transmission data were available and only fission cross-section measurements were analyzed. However, since the analysis conserves the complete covariance matrix, the analysis can be updated by the Bayes method as transmission measurements become available. To date, the analysis of the fission measurements has been completed up to 300 eV.
Graphs of neutron cross sections in JSD1000 for radiation shielding safety analysis
International Nuclear Information System (INIS)
Yamano, Naoki
1984-03-01
Graphs of neutron cross sections and self-shielding factors in the JSD1000 library are presented for radiation shielding safety analysis. The compilation contains various reaction cross sections for 42 nuclides from 1 H to 241 Am in the energy range from 3.51 x 10 -4 eV to 16.5 MeV. The Bondarenko-type self-shielding factors of each reaction are given by the background cross sections from σ 0 = 0 to σ 0 = 10000. (author)
Study of the molecular structure and dynamics of bakelite with neutron cross section measurements
International Nuclear Information System (INIS)
Voi, D.L.
1990-06-01
The molecular structure and dynamics of calcined bakelite were studied with neutron transmission and scattering cross section measurements. The total cross sections determined were correlated with data obtained with infra-red spectroscopy, elemental analysis and other techniques to get the probable molecular formulae of bakelite. The total cross section determined showed a deviation smaller than 5% from the literature values. The frequency distribution as well as overall experimental results allowed to suggest a structural model like polycyclic hydrocarbons for bakelite calcined at 800 0 C. (F.E.). 65 refs, 31 figs, 5 tabs
SHIELD and HZETRN comparisons of pion production cross sections
Norbury, John W.; Sobolevsky, Nikolai; Werneth, Charles M.
2018-03-01
A program of comparing American (NASA) and Russian (ROSCOSMOS) space radiation transport codes has recently begun, and the first paper directly comparing the NASA and ROSCOSMOS space radiation transport codes, HZETRN and SHIELD respectively has recently appeared. The present work represents the second time that NASA and ROSCOSMOS calculations have been directly compared, and the focus here is on models of pion production cross sections used in the two transport codes mentioned above. It was found that these models are in overall moderate agreement with each other and with experimental data. Disagreements that were found are discussed.
Parton distributions with the combined HERA charm production cross sections
International Nuclear Information System (INIS)
Bertone, Valerio; Rojo, Juan
2013-01-01
Heavy quark structure functions from HERA provide a direct handle on the medium and small-x gluon PDF. In this contribution, we discuss ongoing progress on the implementation of the FONLL General-Mass scheme with running heavy quark masses, and of its benchmarking with the HOPPET and OpenQCDrad codes, and then present the impact of the recently released combined HERA charm production cross sections in the NNPDF 2.3 analysis. We find that the combined charm data contribute to constraining the gluon and quarks at small values of Bjorken-x.
Parton distributions with the combined HERA charm production cross sections
Energy Technology Data Exchange (ETDEWEB)
Bertone, Valerio [Physikalisches Institut, Albert-Ludwigs-Universitaet Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg i. B (Germany); Rojo, Juan [PH Department, TH Unit, CERN, CH-1211 Geneva 23 (Switzerland)
2013-04-15
Heavy quark structure functions from HERA provide a direct handle on the medium and small-x gluon PDF. In this contribution, we discuss ongoing progress on the implementation of the FONLL General-Mass scheme with running heavy quark masses, and of its benchmarking with the HOPPET and OpenQCDrad codes, and then present the impact of the recently released combined HERA charm production cross sections in the NNPDF 2.3 analysis. We find that the combined charm data contribute to constraining the gluon and quarks at small values of Bjorken-x.
Photo-neutron cross sections for unstable neutron-rich oxygen isotopes
International Nuclear Information System (INIS)
Leistenschneider, A.; Aumann, T.; Boretzky, K.
2001-05-01
The dipole response of stable and unstable neutron-rich oxygen nuclei of masses A = 17 to A = 22 has been investigated experimentally utilizing electromagnetic excitation in heavy-ion collisions at beam energies around 600 MeV/nucleon. A kinematically complete measurement of the neutron decay channel in inelastic scattering of the secondary beam projectiles from a Pb target was performed. Differential electromagnetic excitation cross sections dσ/dE were derived up to 30 MeV excitation energy. In contrast to stable nuclei, the deduced dipole strength distribution appears to be strongly fragmented and systematically exhibits a considerable fraction of low-lying strength, exhausting up to 12% of the energy-weighted dipole sum rule at excitation energies below 15 MeV. (orig.)
Neutron-photon multigroup cross sections for neutron energies up to 400 MeV: HILO86R
International Nuclear Information System (INIS)
Kotegawa, Hiroshi; Nakane, Yoshihiro; Hasegawa, Akira; Tanaka, Shun-ichi
1993-02-01
A macroscopic multigroup cross section library of 66 neutron and 22 photon groups for neutron energies up to 400 MeV: HILO86R is prepared for 10 typical shielding materials; water, concrete, iron, air, graphite, polyethylene, heavy concrete, lead, aluminum and soil. The library is a revision of the DLC-119/HILO86, in which only the cross sections below 19.6 MeV have been exchanged with a group cross section processed from the JENDL-3 microscopic cross section library. In the HILO86R library, self shielding factors are used to produce effective cross sections for neutrons less than 19.6 MeV considering rather coarse energy meshes. Energy spectra and dose attenuation in water, concrete and iron have been compared among the HILO, HILO86 and HILO86R libraries for different energy neutron sources. Significant discrepancy has been observed in the energy spectra less than a couple of MeV energy in iron among the libraries, resulting large difference in the dose attenuation. The difference was attributed to the effect of self-shielding factor, namely to the difference between infinite dilution and effective cross sections. Even for 400 MeV neutron source the influence of the self-shielding factor is significant, nevertheless only the cross sections below 19.6 MeV are exchanged. (author)
Evaluation of neutron cross sections to 40 MeV for 5456Fe
International Nuclear Information System (INIS)
Arthur, E.D.; Young, P.G.
1980-01-01
Cross sections for neutron-induced reactions on 54 56 Fe were calculated by employing several nuclear models: optical, Hauser-Feshbach, preequilibrium and DWBA - in the energy range between 3 and 40 MeV. As a prelude to the calculations, the necessary input parameters were determined or verified through analysis of a large body of experimental data for both neutron- and proton-induced reactions in this mass and energy region. This technique also led to cross sections in which the simultaneous influence of available data types added to their consistency and reliability. Calculated cross sections as well as neutron and gamma-ray emission spectra were incorporated into an ENDF evaluation suitable for use to 40 MeV. 12 figures, 1 table
Talys calculations for evaluation of neutron-induced single-event upset cross sections
Energy Technology Data Exchange (ETDEWEB)
Bourselier, Jean-Christophe
2005-08-15
The computer code TALYS has been used to calculate interactions between cosmic-ray neutrons and silicon nuclei with the goal to describe single-event upset (SEU) cross sections in microelectronics devices. Calculations for the Si(n,X) reaction extend over an energy range of 2 to 200 MeV. The obtained energy spectra of the resulting residuals and light-ions have been integrated using several different critical charges as SEU threshold. It is found that the SEU cross section seems largely to be dominated by {sup 28}Si recoils from elastic scattering. Furthermore, the shape of the SEU cross section as a function of the energy of the incoming neutron changes drastically with decreasing critical charge. The results presented in this report stress the importance of performing studies at mono-energetic neutron beams to advance the understanding of the underlying mechanisms causing SEUs.
Fast-neutron total and scattering cross sections of sup 58 Ni and nuclear models
Energy Technology Data Exchange (ETDEWEB)
Smith, A.B.; Guenther, P.T.; Whalen, J.F. (Argonne National Lab., IL (United States)); Chiba, S. (Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment)
1991-07-01
The neutron total cross sections of {sup 58}Ni were measured from {approx} 1 to > 10 MeV using white-source techniques. Differential neutron elastic-scattering cross sections were measured from {approx} 4.5 to 10 MeV at {approx} 0.5 MeV intervals with {ge} 75 differential values per distribution. Differential neutron inelastic-scattering cross sections were measured, corresponding to fourteen levels with excitations up to 4.8 MeV. The measured results, combined with relevant values available in the literature, were interpreted in terms of optical-statistical and coupled-channels model using both vibrational and rotational coupling schemes. The physical implications of the experimental results nd their interpretation are discussed in the contexts of optical-statistical, dispersive-optical, and coupled-channels models. 61 refs.
International Nuclear Information System (INIS)
Czubek, J.A.; Burda, J.; Drozdowicz, K.; Igielski, A.; Kowalik, W.; Krynicka-Drozdowicz, E.; Woznicka, U.
1986-03-01
Preparation of rock samples for the measurement of the thermal neutron macroscopic absorption cross-section in small cylindrical two-region systems by a pulsed technique is presented. Requirements which should be fulfilled during the preparation of the samples due to physical assumptions of the method are given. A cylindrical vessel is filled with crushed rock and saturated with a medium strongly absorbing thermal neutrons. Water solutions of boric acid of well-known macroscopic absorption cross-section are used. Mass contributions of the components in the sample are specified. This is necessary for the calculation of the thermal neutron macroscopic absorption cross-section of the rock matrix. The conditions necessary for assuring the required accuracy of the measurement are given and the detailed procedure of preparation of the rock sample is described. (author)
Talys calculations for evaluation of neutron-induced single-event upset cross sections
International Nuclear Information System (INIS)
Bourselier, Jean-Christophe
2005-08-01
The computer code TALYS has been used to calculate interactions between cosmic-ray neutrons and silicon nuclei with the goal to describe single-event upset (SEU) cross sections in microelectronics devices. Calculations for the Si(n,X) reaction extend over an energy range of 2 to 200 MeV. The obtained energy spectra of the resulting residuals and light-ions have been integrated using several different critical charges as SEU threshold. It is found that the SEU cross section seems largely to be dominated by 28 Si recoils from elastic scattering. Furthermore, the shape of the SEU cross section as a function of the energy of the incoming neutron changes drastically with decreasing critical charge. The results presented in this report stress the importance of performing studies at mono-energetic neutron beams to advance the understanding of the underlying mechanisms causing SEUs
Resonance structure of 32S+n from measurements of neutron total and capture cross sections
International Nuclear Information System (INIS)
Halperin, J.; Johnson, C.H.; Winters, R.R.; Macklin, R.L.
1980-01-01
Neutron total and capture cross sections of 32 S have been measured up to 1100 keV neutron energy [E/sub exc/( 33 S) =9700 keV]. Spin and parity assignments have been made for 28 of the 64 resonances found in this region. Values of total radiation widths, reduced neutron widths, level spacings, and neutron strength functions have been evaluated for s/sub 1/2/, p/sub 1/2/, p/sub 3/2/, and d/sub 5/2/ levels. Single particle contributions using the valency model account for a significant portion of the total radiation width only for the p/sub 1/2/-wave resonances. A significant number of resonances can be identified with reported levels excited in 32 S(d,p) and 29 Si(α,n) reactions. A calculation of the Maxwellian average cross section appropriate to stellar interiors indicates an average capture cross section at 30 keV, sigma-bar approx. = 4.2(2) mb, a result that is relatively insensitive to the assumed stellar temperature. Direct (potential) capture and the s-wave resonance capture contributions to the thermal capture cross section do not fully account for the reported thermal cross section (530 +- 40 mb) and a bound state is invoked to account for the discrepancy
Energy Technology Data Exchange (ETDEWEB)
Shinohara, N.; Hatsukawa, Y.; Hata, K.; Kohno, N. [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment
1997-03-01
The thermal neutron capture cross section {sigma}{sub 0} and Resonance integral I{sub 0} of {sup 241}Am leading to the production of {sup 242m}Am and {sup 242g}Am were measured by radiochemical method. The cross sections obtained in this study are {sigma}{sub 0}=60.9 {+-} 2.6 barn, I{sub 0}=213 {+-} 13 barn for {sup 241}Am(n,{gamma}){sup 242m}Am and {sigma}{sub 0}=736 {+-} 31 barn, I{sub 0}=1684 {+-} 92 barn for {sup 241}Am(n,{gamma}){sup 242g}Am. (author)
Analysis of the 235U neutron cross sections in the resolved resonance range
International Nuclear Information System (INIS)
Leal, L.C.; de Saussure, G.; Perez, R.B.
1989-01-01
Using recent high-resolution measurements of the neutron transmission of 235 U and the spin-separated fission cross-section data of Moore et al., a multilevel analysis of the 235 U neutron cross sections was performed up to 300 eV. The Dyson Metha Δ 3 statistics were used to help locate small levels above 100 eV where resonances are not clearly resolved even in the best resolution measurements available. The statistical properties of the resonance parameters are discussed
Analysis of the 235U neutron cross sections in the resolved resonance range
International Nuclear Information System (INIS)
Leal, L.C.; de Saussure, G.; Perez, R.B.
1989-01-01
Using recent high-resolution measurements of the neutron transmission of 235 U and the spin-separated fission cross-section data of Moore et al., a multilevel analysis of the 235 U neutron cross sections was performed up to 300 eV. The Dyson Metha Δ 3 statistics were used to help locate small levels above 100 eV where resonances are not clearly resolved even in the best resolution measurements available. The statistical properties of the resonance parameters are discussed. 13 refs., 8 figs., 1 tab
Neutron cross section covariances in the resonance region: 52Cr, 56Fe, 58Ni
Energy Technology Data Exchange (ETDEWEB)
Oblozinsky, P.; Cho, Y.-S.; Mattoon, C.M.; Mughabghab, S.F.
2010-08-03
We evaluated covariances for neutron capture and elastic scattering cross sections on major structural materials, {sup 52}Cr, {sup 56}Fe and {sup 58}Ni, in the resonance region which extends beyond 800 keV for each of them. Use was made of the recently developed covariance formalism based on kernel approximation along with data in the Atlas of Neutron Resonances. The data of most interest for AFCI applications, elastic scattering cross section uncertainties at energies above about few hundred keV, are on the level of about 12% for {sup 52}Cr, 7-8% for {sup 56}Fe and 5-6% for {sup 58}Ni.
Neutron cross section and covariance data evaluation of experimental data for {sup 27}Al
Energy Technology Data Exchange (ETDEWEB)
Chunjuan, Li; Jianfeng, Liu [Physics Department , Zhengzhou Univ., Zhengzhou (China); Tingjin, Liu [China Nuclear Data Center, China Inst. of Atomic Energy, Beijing (China)
2006-07-15
The evaluation of neutron cross section and covariance data for {sup 27}Al in the energy range from 210 keV to 20 MeV was carried out on the basis of the experimental data mainly taken from EXFOR library. After the experimental data and their errors were analyzed, selected and corrected, SPCC code was used to fit the data and merge the covariance matrix. The evaluated neutron cross section data and covariance matrix for {sup 27}Al given can be collected for the evaluated library and also can be used as the basis of theoretical calculation concerned. (authors)
Neutron cross section and covariance data evaluation of experimental data for 27Al
International Nuclear Information System (INIS)
Li Chunjuan; Liu Jianfeng; Liu Tingjin
2006-01-01
The evaluation of neutron cross section and covariance data for 27 Al in the energy range from 210 keV to 20 MeV was carried out on the basis of the experimental data mainly taken from EXFOR library. After the experimental data and their errors were analyzed, selected and corrected, SPCC code was used to fit the data and merge the covariance matrix. The evaluated neutron cross section data and covariance matrix for 27 Al given can be collected for the evaluated library and also can be used as the basis of theoretical calculation concerned. (authors)
Measurements of neutron-induced fission cross sections of Pb and Bi at intermediate energies
International Nuclear Information System (INIS)
Ryzhov, Igor; Tutin, Gennady; Eismont, Vilen; Mitryukhin, Andrey; Oplavin, Valery; Soloviev, Sergey; Conde, Henri; Olsson, Nils; Renberg, Per-Ulf
2002-01-01
Neutron-induced fission cross sections of nat Pb and 209 Bi have been measured relative to the 238 U(n.f) cross section at energies 96 MeV for lead and 133 MeV for bismuth. The measurements were performed at the quasi-mono-energetic neutron beam facility of The Svedberg Laboratory in Uppsala using Frisch-gridded ionization chamber. The results obtained are compared with other experimental data. The present state of the Bi standard recommended by IAEA is discussed. (author)
Thermal neutron radiative capture cross-section of 186W(n, γ)187W reaction
International Nuclear Information System (INIS)
Tan, V H; Son, P N
2016-01-01
The thermal neutron radiative capture cross section for 186 W(n, γ) 187 W reaction was measured by the activation method using the filtered neutron beam at the Dalat research reactor. An optimal composition of Si and Bi, in single crystal form, has been used as neutron filters to create the high-purity filtered neutron beam with Cadmium ratio of R cd = 420 and peak energy E n = 0.025 eV. The induced activities in the irradiated samples were measured by a high resolution HPGe digital gamma-ray spectrometer. The present result of cross section has been determined relatively to the reference value of the standard reaction 197 Au(n, γ) 198 Au. The necessary correction factors for gamma-ray true coincidence summing, and thermal neutron self-shielding effects were taken into account in this experiment by Monte Carlo simulations. (paper)
Measurement of (n,α) cross-sections for Cr, Fe and Ni at 14 MeV neutron energy
International Nuclear Information System (INIS)
Wattecamps, E.; Liskien, H.; Arnotte, F.
1983-01-01
Helium production cross-sections for the main constituents of stainless steel (Cr, Fe, Ni) have recently been published for neutron energies between 5 and 10 MeV. The α-particles were detected with a multi-angle telescope and cross-section data relative to the well known n-p scattering cross-section were deduced. Those measurements have been performed now also at 14 MeV. At this energy the background condition had to be improved by changing the neutron collimation, by reducing the sensitive volume of the ΔE-proportional counters, and by replacing remaining low-Z material inside the chamber by tantalum. Listing mode data acquisition is used and α-particle identification is performed by transforming the observed (ΔE,E) signal into a (MZ 2 ,E) signal. The measurements yield the angle-differential cross sections for five fixed angles. Angle-integrated cross-sections are compared with the few results available in literature. (Auth.)
Production cross sections of proton-induced reactions on yttrium
Energy Technology Data Exchange (ETDEWEB)
Yang, Sung-Chul; Song, Tae-Yung; Lee, Young-Ouk [Nuclear Data Center, Korea Atomic Energy Research Institute, Daejeon 34057 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics, Kyungpook National University, Daegu 41566 (Korea, Republic of)
2017-05-01
The production cross sections of residual radionuclides such as {sup 86,88,89g}Zr, {sup 86g,87m,87g,88}Y, {sup 83g,85g}Sr, and {sup 83,84g}Rb in the {sup 89}Y(p,x) reaction were measured using a stacked-foil activation and offline γ-ray spectrometric technique with proton energies of 57 MeV and 69 MeV at the 100 MeV proton linac in the Korea Multi-purpose Accelerator Complex (KOMAC), Gyeongju, Korea. The induced activities of the activated samples were measured using a high purity germanium (HPGe) detector, and the proton flux was determined using the {sup nat}Cu(p,x){sup 62}Zn reaction. The measured data was compared with other experimental data and the data from the TENLD-2015 library based on the TALYS code. The present results are generally lower than those in literature, but are found to be in agreement with the shape of the excitation functions. The integral yields for the thick target using the measured cross sections are given.
International Nuclear Information System (INIS)
Weise, L.
1986-04-01
In the framework of the development of a fusion reactor blanket the irradiation experiment TRIDEX (Tritium Recovery Irradiation DIDO Experiment) takes place at the Juelich Research Reactor FRJ-2 (DIDO). For this equipment the required neutronic calculations have been performed. The aim was the determination of the neutron spectrum and several therefrom derived integral parameters for the irradiation positions in interest. From the calculated effective cross sections for the formation of Tritium resulting from irradiated Lithium samples on one hand and from measured neutron flux densities on the other hand, all needed quantities of the Tritium production could be determined. The calculation of the neutron spectrum has been performed in a two-dimensional x-y-geometry. The neutron flux densities have been gained by gamma-spectrometric measurement of the activities in irradiated activation samples. (orig.) [de
International Nuclear Information System (INIS)
Garg, S.B.
1991-01-01
A detailed investigation is carried out to determine the effect of different level density prescriptions on the computed neutron nuclear data of Ni-58 in the energy range 5-25 MeV. Calculations are performed in the framework of the multistep Hauser-Feshbach statistical theory including the Kalbach exciton model and Brink-Axel giant dipole resonance model for radiative capture. Level density prescriptions considered in this investigation are based on the original Gilbert-Cameron, improved Gilbert-Cameron, backshifted Fermi-gas and the Ignatyuk, et al. approaches. The effect of these prescriptions is discussed, with special reference to (n,p), (n,2n), (n,alpha) and total particle-production cross sections. (author). 17 refs, 8 figs
International Nuclear Information System (INIS)
Peter Bosted; M. E. Christy
2007-01-01
An empirical fit is described to measurements of inclusive inelastic electron-deuteron cross sections in the kinematic range of four-momentum transfer 0 (le) Q 2 2 and final state invariant mass 1.2 p of longitudinal to transverse cross sections for the proton, and the assumption R p =R n . The underlying fit parameters describe the average cross section for proton and neutron, with a plane-wave impulse approximation (PWIA) used to fit to the deuteron data. Pseudo-data from MAID 2007 were used to constrain the average nucleon cross sections for W<1.2 GeV. The mean deviation of data from the fit is 3%, with less than 5% of the data points deviating from the fit by more than 10%
International Nuclear Information System (INIS)
Ribon, P.; Maillard, J.M.
1986-09-01
The idea of describing neutron cross-section fluctuations by sets of discrete values, called ''probability tables'', was formulated some 15 years ago. We propose to define the probability tables from moments by equating the moments of the actual cross-section distribution in a given energy range to the moments of the table. This definition introduces PADE approximants, orthogonal polynomials and GAUSS quadrature. This mathematical basis applies very well to the total cross-section. Some difficulties appear when partial cross-sections are taken into account, linked to the ambiguity of the definition of multivariate PADE approximants. Nevertheless we propose solutions and choices which appear to be satisfactory. Comparisons are made with other definitions of probability tables and an example of the calculation of a mixture of nuclei is given. 18 refs
PEGASUS: a preequilibrium and multi-step evaporation code for neutron cross section calculation
Energy Technology Data Exchange (ETDEWEB)
Nakagawa, Tsuneo; Sugi, Teruo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Iijima, Shungo; Nishigori, Takeo
1999-06-01
The computer code PEGASUS was developed to calculate neutron-induced reaction cross sections on the basis of the closed form exciton model preequilibrium theory and the multi-step evaporation theory. The cross sections and emitted particle spectra are calculated for the compound elastic scattering, (n,{gamma}), (n,n`), (n,p), (n,{alpha}), (n,d), (n,t), (n,{sup 3}He), (n,2n), (n,n`p), (n,n`{alpha}), (n,n`d), (n,n`t), (n,2p) and (n,3n) reactions. The double differential cross sections of emitted particles are also calculated. The calculated results are written on a magnetic disk in the ENDF format. Parameter files and/or systematics formulas are provided for level densities, mass excess, radiation widths and inverse cross sections so that the input data to the code are made minimum. (author)
International Nuclear Information System (INIS)
Ribon, P.; Maillard, J.M.
1986-01-01
The idea of describing neutron cross-section fluctuations by sets of discrete values, called probability tables, was formulated some 15 years ago. The authors propose to define the probability tables from moments by equating the moments of the actual cross-section distribution in a given energy range to the moments of the table. This definition introduces PADE approximants, orthogonal polynomials and GAUSS quadrature. This mathematical basis applies very well to the total cross-section. Some difficulties appear when partial cross-sections are taken into account, linked to the ambiguity of the definition of multivariate PADE approximants. Nevertheless the authors propose solutions and choices which appear to be satisfactory. Comparisons are made with other definition of probability tables and an example of the calculation of a mixture of nuclei is given
Neutron capture cross section of $^{90}$Zr Bottleneck in the s-process reaction flow
Tagliente, G; Milazzo, P M; Moreau, C; Aerts, G; Abbondanno, U; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, Panayiotis; Audouin, L; Badurek, G; Baumann, P; Bečvář, F; Berthoumieux, E; Bisterzo, S; Calviño, F; Calviani, M; Cano-Ott, D; Capote, R; Carrapiço, C; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillman, I; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Furman, W; Gallino, R; Gonçalves, I; Gonzalez-Romero, E; Gramegna, F; Guerrero, C; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Karamanis, D; Kerveno, M; Köhler, P; Kossionides, E; Krtička, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martínez, T; Massimi, C; Mastinu, P; Mengoni, A; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Pigni, M T; Plag, R; Plompen, A; Plukis, A; Poch, A; Praena, J; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Santos, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M, C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescher, M; Wisshak, K
2008-01-01
The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. The small cross section of the neutron magic nucleus 90Zr, which accounts for more than 50% of natural zirconium represents one of the key isotopes for the stellar s-process, because it acts as a bottleneck in the neutron capture chain between the Fe seed and the heavier isotopes. The same element, Zr, also is an important component of the structural materials used in traditional and advanced nuclear reactors. The (n,γ) cross section has been measured at CERN, using the n_TOF spallation neutron source. In total, 45 resonances could be resolved in the neutron energy range below 70 keV, 10 being observed for the first time thanks to the high resolution and low backgrounds at n_TOF. On average, the Γγ widths obtained in resonance analyses with the R-matrix code SAMMY were 15% smaller than reported previously. By these results, the accuracy of the Maxwellian averaged cross section f...
Testing of ENDF/B cross section data in the Californium-252 neutron benchmark field
International Nuclear Information System (INIS)
Mannhart, W.
1979-01-01
The fission neutron field of 252 Cf presently represents one of the most well-known neutron benchmark fields. For 13 neutron reactions which are of importance in reactor metrology, measurements of spectrum-averaged cross sections, [sigma], performed in this neutron field were compared with calculated average cross sections. This comparison allows one to draw conclusions as to the quality of different sigma(E) data taken from ENDF/B-IV, from ENDF/B-V, and from recent experiments and used in the calculation of average cross sections. The comparison includes an uncertainty analysis regarding the different uncertainty contributions of [sigma], of sigma(E), and of the spectral distribution of 252 Cf fission neutrons. Additionally, in a few examples, sensitivity studies were carried out. The sensitivity of the spectrum-averaged cross sections to individual characteristics of the sigma(E) data, such as normalization factors or shifts in the energy scale, was investigated. Similarly, the sensitivity of [sigma] to the spectral distribution of 252 Cf was determined. 4 figures, 2 tables
International Nuclear Information System (INIS)
Alsmiller, R.G. Jr.; Barnes, J.M.; Drischler, J.D.
1986-01-01
For a variety of applications, e.g., accelerator shielding design, neutrons in radiotherapy, radiation damage studies, etc., it is necessary to carry out transport calculations involving medium-energy (greater than or equal to20 MeV) neutrons. A previous paper described neutron-photon multigroup cross sections in the ANISN format for neutrons from thermal to 400 MeV. In the present paper the cross-section data presented previously have been revised to make them agree with available experimental data. 7 refs., 1 fig
Measurement of fast neutron induced fission cross section of minor-actinide
International Nuclear Information System (INIS)
Hirakawa, Naohiro
2000-06-01
In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron accelerator in Tohoku University. The followings were performed in this fiscal year; (1) Research of nuclear data of MA, (2) Sample preparation and sample mass assay, (3) Investigation of neutron sources with the energy of several 10 keV, (4) Preliminary measurement of fission cross section using Dynamitron accelerator. As the result, four 237 Np samples were prepared and the sample mass were measured using alpha-spectrometry with the accuracy of 1.2%. Then, it was confirmed that a neutron source via 7 Li(p,n) 7 Be reaction using a Li-thick target is suitable for measuring fission cross section of MA in the energy region of several 10 keV. Furthermore, it was verified by the preliminary measurement that the measurement of fission cross section of MA is available using a fission chamber and electronics developed in this study. (author)
Energy-averaged neutron cross sections of fast-reactor structural materials
International Nuclear Information System (INIS)
Smith, A.; McKnight, R.; Smith, D.
1978-02-01
The status of energy-averaged cross sections of fast-reactor structural materials is outlined with emphasis on U.S. data programs in the neutron-energy range 1-10 MeV. Areas of outstanding accomplishment and significant uncertainty are noted with recommendations for future efforts. Attention is primarily given to the main constituents of stainless steel (e.g., Fe, Ni, and Cr) and, secondarily, to alternate structural materials (e.g., V, Ti, Nb, Mo, Zr). Generally, the mass regions of interest are A approximately 50 to 60 and A approximately 90 to 100. Neutron total and elastic-scattering cross sections are discussed with the implication on the non-elastic-cross sections. Cross sections governing discrete-inelastic-neutron-energy transfers are examined in detail. Cross sections for the reactions (n;p), (n;n',p), (n;α), (n;n',α) and (n;2n') are reviewed in the context of fast-reactor performance and/or diagnostics. The primary orientation of the discussion is experimental with some additional attention to the applications of theory, the problems of evaluation and the data sensitivity of representative fast-reactor systems
Methods and procedures for evaluation of neutron-induced activation cross sections
International Nuclear Information System (INIS)
Gardner, M.A.
1981-09-01
One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed
Methods and procedures for evaluation of neutron-induced activation cross sections
Energy Technology Data Exchange (ETDEWEB)
Gardner, M.A.
1981-09-01
One cannot expect measurements alone to supply all of the neutron-induced activation cross-section data required by the fission reactor, fusion reactor, and nuclear weapons development communities, given the wide ranges of incident neutron energies, the great variety of possible reaction types leading to activation, and targets both stable and unstable. Therefore, the evaluator must look to nuclear model calculations and systematics to aid in fulfilling these cross-section data needs. This review presents some of the recent developments and improvements in the prediction of neutron activation cross sections, with specific emphasis on the use of empirical and semiempirical methods. Since such systematics require much less nuclear informaion as input and much less computational time than do the multistep Hauser-Feshbach codes, they can often provide certain cross-section data at a sufficient level of accuracy within a minimum amount of time. The cross-section information that these systematics can and cannot provide and those cases in which they can be used most reliably are discussed.
Holmes, Jesse Curtis
Nuclear data libraries provide fundamental reaction information required by nuclear system simulation codes. The inclusion of data covariances in these libraries allows the user to assess uncertainties in system response parameters as a function of uncertainties in the nuclear data. Formats and procedures are currently established for representing covariances for various types of reaction data in ENDF libraries. This covariance data is typically generated utilizing experimental measurements and empirical models, consistent with the method of parent data production. However, ENDF File 7 thermal neutron scattering library data is, by convention, produced theoretically through fundamental scattering physics model calculations. Currently, there is no published covariance data for ENDF File 7 thermal libraries. Furthermore, no accepted methodology exists for quantifying or representing uncertainty information associated with this thermal library data. The quality of thermal neutron inelastic scattering cross section data can be of high importance in reactor analysis and criticality safety applications. These cross sections depend on the material's structure and dynamics. The double-differential scattering law, S(alpha, beta), tabulated in ENDF File 7 libraries contains this information. For crystalline solids, S(alpha, beta) is primarily a function of the material's phonon density of states (DOS). Published ENDF File 7 libraries are commonly produced by calculation and processing codes, such as the LEAPR module of NJOY, which utilize the phonon DOS as the fundamental input for inelastic scattering calculations to directly output an S(alpha, beta) matrix. To determine covariances for the S(alpha, beta) data generated by this process, information about uncertainties in the DOS is required. The phonon DOS may be viewed as a probability density function of atomic vibrational energy states that exist in a material. Probable variation in the shape of this spectrum may be
Total cross sections for heavy flavour production at HERA
Frixione, Stefano; Nason, P; Ridolfi, G; Frixione, S; Mangano, M L; Nason, P; Ridolfi, G
1995-01-01
We compute total cross sections for charm and bottom photoproduction at HERA energies, and discuss the relevant theoretical uncertainties. In particular we discuss the problems arising from the small-x region, the uncertainties in the gluon parton density, and the uncertainties in the hadronic component of the cross section. Total electroproduction cross sections, calculated in the Weizs\\"acker-Williams approximation, are also given.
International Nuclear Information System (INIS)
Belanova, T.S.
1994-12-01
Data on the thermal neutron fission and capture cross-sections as well as their corresponding resonance integrals are reviewed and analysed. The data are classified according to the form of neutron spectra under investigation. The weighted mean values of the cross-sections and resonance integrals for every type of neutron spectra were adopted as evaluated data. (author). 87 refs, 2 tabs
International Nuclear Information System (INIS)
Guber, Klaus H.; Leal, Luiz C.; Sayer, Royce O.; Spencer, Robert R.; Koehler, Paul E.; Valentine, Timothy E.; Derrien, Herve; Harvey, John A.
2002-01-01
The Oak Ridge Electron Linear Accelerator (ORELA) was used to measure neutron total and capture cross sections of aluminium, natural chlorine and silicon in the energy range from 100 eV to ∼600 keV. ORELA is the only high power white neutron source with excellent time resolution and ideally suited for these experiments still operating in the USA. These measurements were carried out to support the Nuclear Criticality Predictability Program. Concerns about the use of existing cross section data in the nuclear criticality calculations using Monte Carlo codes and benchmarks have been a prime motivator for the new cross section measurements. More accurate nuclear data are not only needed for these calculations but also serve as input parameters for s-process stellar models. (author)
Measurement of the neutron-induced fission cross-section of 240,242Pu
International Nuclear Information System (INIS)
Salvador-Castineira, P.; Hambsch, F.J.; Brys, T.; Oberstedt, S.; Vidali, M.; Pretel, C.
2014-01-01
Fast spectrum neutron-induced fission cross-section data for transuranic isotopes are in high demand in the nuclear data community. In particular, highly accurate data are needed for the new Generation-IV nuclear applications. The aim is to obtain precise neutron-induced fission cross-sections for 240 Pu and 242 Pu. In this context accurate data on spontaneous fission half-lives have also been measured. To minimise the total uncertainty on the fission cross-sections the detector efficiency has been studied in detail. Both isotopes have been measured using a twin Frisch-grid ionisation chamber (TFGIC) due to its superiority compared to other detector systems in view of radiation hardness, 2 x 2π solid angle coverage and very good energy resolution. (authors)
The measurement of anomalous neutron inelastic cross-sections at electronvolt energy transfers
International Nuclear Information System (INIS)
Mayers, J; Abdul-Redah, T
2004-01-01
It has been proposed that short-lived quantum entanglement of protons in condensed matter systems would result in anomalous inelastic scattering cross-sections at electronvolt energy transfers. This proposal seems to be confirmed by neutron measurements on the VESUVIO spectrometer at ISIS and by measurements using other techniques. However, there have been a number of published suggestions of ways in which the observed effects on VESUVIO could be introduced by assumptions used in the data analysis. In this paper it is shown using experimental data and Monte Carlo simulations that these suggestions cannot explain the observed cross-section anomalies. The other assumptions of the data analysis are also examined. It is shown that the assumption of a Gaussian peak shape for the neutron Compton profile can introduce significant errors into the determination of cross-section ratios, but also cannot explain the observed anomalies
International Nuclear Information System (INIS)
Konodeev, A.Yu.; Korovin, Yu.A.; Erview, K.
1993-01-01
Research is at present concerned with the possible transmutation of long-lived radionuclides of spent nuclear fuel in the flux of fast neutrons from neutron generators which are distinguished by their energy spectrum and density of the flux generated. For this purpose one must know the cross sections of the nuclear reactions resulting in the transmutation and formation of new long-lived radionuclides due to the irradiation. The transmutation rate of radioisotope irradiated with neutrons have a known energy spectrum is determined by calculating the transmutation cross section which is equal to the sum of the cross sections of neutron reactions causing conversion of a particular isotope into another after the decay of short-lived residual nuclei. The presently available neutron cross section data of long-lived radionuclides, i.e., the products of the fission of nuclear fuel, are insufficient for research on these effects as transmutations occur in a flux of high-energy neutrons. This paper presents the cross sections of reactions accounting for the transmutation of the most important long-lived radionuclides of exhausted nuclear fuel during its irradiation with neutron having energies of up to 100 MeV. The neutron cross sections were calculated for 79 Se, 90 Sr, 93 Zr, 99 Tc, 107 Pd, 126 Sn, 129 I, 135 Cs and 137 Cs with a half-life ≥30 years
International Nuclear Information System (INIS)
Fabry, A.; McElroy, W.N.; Kellogg, L.S.; Lippincott, E.P.; Grundl, J.A.; Gilliam, D.M.; Hansen, G.E.
1976-01-01
This paper is intended to review and critically discuss microscopic integral cross section measurement and calculation data for fundamental reactor dosimetry benchmark neutron fields. Specifically the review covers the following fundamental benchmarks: the spontaneous californium-252 fission neutron spectrum standard field; the thermal-neutron induced uranium-235 fission neutron spectrum standard field; the (secondary) intermediate-energy standard neutron field at the center of the Mol-ΣΣ, NISUS, and ITN-ΣΣ facilities; the reference neutron field at the center of the Coupled Fast Reactor Measurement Facility; the reference neutron field at the center of the 10% enriched uranium metal, cylindrical, fast critical; the (primary) Intermediate-Energy Standard Neutron Field
International Nuclear Information System (INIS)
Fabry, A.; McElroy, W.N.; Kellogg, L.S.; Lippincott, E.P.; Grundl, J.A.; Gilliam, D.M.; Hansen, G.E.
1976-10-01
The paper is intended to review and critically discuss microscopic integral cross section measurement and calculation data for fundamental reactor dosimetry benchmark neutron fields. Specifically the review covers the following fundamental benchmarks: (1) the spontaneous californium-252 fission neutron spectrum standard field; (2) the thermal-neutron induced uranium-235 fission neutron spectrum standard field; (3) the (secondary) intermediate-energy standard neutron field at the center of the Mol-ΣΣ, NISUS, and ITN--ΣΣ facilities; (4) the reference neutron field at the center of the Coupled Fast Reactor Measurement Facility (CFRMF); (5) the reference neutron field at the center of the 10 percent enriched uranium metal, cylindrical, fast critical; and (6) the (primary) Intermediate-Energy Standard Neutron Field
New production cross sections for the theranostic radionuclide 67Cu
Pupillo, Gaia; Sounalet, Thomas; Michel, Nathalie; Mou, Liliana; Esposito, Juan; Haddad, Férid
2018-01-01
The cross sections of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were measured at the ARRONAX facility by using the 70 MeV cyclotron, with particular attention to the production of the theranostic radionuclide 67Cu. Enriched 68Zn material was electroplated on silver backing and exposed to a low-intensity proton beam by using the stacked-foils target method. Since 67Cu and 67Ga radionuclides have similar half-lives and same γ-lines (they both decay to 67Zn), a radiochemical process aimed at Cu/Ga separation was mandatory to avoid interferences in γ-spectrometry measurements. A simple chemical procedure having a high separation efficiency (>99%) was developed and monitored during each foil processing, thanks to the tracer isotopes 61Cu and 66Ga. Nuclear cross sections were measured in the energy range 35-70 MeV by using reference reactions recommended by the International Atomic Energy Agency (IAEA) to monitor beam flux. In comparison with literature data a general good agreement on the trend of the nuclear reactions was noted, especially with latest measurements, but slightly lower values were obtained in case of 67Cu. Experimental results of the 68Zn(p,2p)67Cu, 68Zn(p,2n)67Ga and 68Zn(p,3n)66Ga reactions were also compared with the theoretical values estimated by using the software TALYS. The production yield of the theranostic radionuclide 67Cu was estimated considering the results obtained in this work.
Neutron cross section measurements at n-TOF for ADS related studies
Mastinu, P. F.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Bustreo, N.; aumann, P.; vá, F. Be; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrillo de Albornoz, A.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Dolfini, R.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; itzpatrick, L.; Frais-Kölbl, H.; Fujii, K.; Furman, W.; Guerrero, C.; Goncalves, I.; Gallino, R.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Isaev, S.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karamanis, D.; Karadimos, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krti ka, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Massimi, C.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wendler, H.; Wiescherand, M.; Wisshak, K.
2006-05-01
A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed.
Neutron cross section measurements at n-TOF for ADS related studies
International Nuclear Information System (INIS)
Mastinu, P F; Abbondanno, U; Aerts, G
2006-01-01
A neutron Time-of-Flight facility (n T OF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n T OF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed
MC2-2: a code to calculate fast neutron spectra and multigroup cross sections
International Nuclear Information System (INIS)
Henryson, H. II; Toppel, B.J.; Stenberg, C.G.
1976-06-01
MC 2 -2 is a program to solve the neutron slowing down problem using basic neutron data derived from the ENDF/B data files. The spectrum calculated by MC 2 -2 is used to collapse the basic data to multigroup cross sections for use in standard reactor neutronics codes. Four different slowing down formulations are used by MC 2 -2: multigroup, continuous slowing down using the Goertzel-Greuling or Improved Goertzel-Greuling moderating parameters, and a hyper-fine-group integral transport calculation. Resolved and unresolved resonance cross sections are calculated accounting for self-shielding, broadening and overlap effects. This document provides a description of the MC 2 -2 program. The physics and mathematics of the neutron slowing down problem are derived and detailed information is provided to aid the MC 2 -2 user in preparing input for the program and implementation of the program on IBM 370 or CDC 7600 computers
Neutron cross section measurements at n-TOF for ADS related studies
Mastinu, P F; Aerts, G; Alvarez, H; Alvarez-Velarde, F; Andriamonje, Samuel A; Andrzejewski, J; Assimakopoulos, P A; Audouin, L; Badurek, G; Bustreo, N; Aumann, P; Beva, F; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Carillo de Albornoz, A; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Couture, A; Cox, J; Dahlfors, M; David, S; Dillmann, I; Dolfini, R; Domingo-Pardo, C; Dridi, W; Durán, I; Eleftheriadis, C; Segura, M E; Ferrant, L; Ferrari, A; Ferreira-Marques, R; itzpatrick, L; Frais-Kölbl, H; Fujii, K; Furman, W; Guerrero, C; Gonçalves, I; Gallino, R; González-Romero, E M; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Igashira, M; Isaev, S; Jericha, E; Kadi, Y; Käppeler, F K; Karamanis, D; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Kossionides, E; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marques, L; Marrone, S; Massimi, C; Mengoni, A; Milazzo, P M; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Oshima, M; Pancin, J; Papachristodoulou, C; Papadopoulos, C; Paradela, C; Patronis, N; Pavlik, A; Pavlopoulos, P; Perrot, L; Plag, R; Plompen, A; Plukis, A; Poch, A; Pretel, C; Quesada, J; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Sarchiapone, L; Savvidis, I; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Vlastou, R; Voss, F; Walter, S; Wendler, H; Wiescherand, M; Wisshak, K
2006-01-01
A neutron Time-of-Flight facility (n_TOF) is available at CERN since 2001. The innovative features of the neutron beam, in particular the high instantaneous flux, the wide energy range, the high resolution and the low background, make this facility unique for measurements of neutron induced reactions relevant to the field of Emerging Nuclear Technologies, as well as to Nuclear Astrophysics and Fundamental Nuclear Physics. The scientific motivations that have led to the construction of this new facility are here presented. The main characteristics of the n_TOF neutron beam are described, together with the features of the experimental apparata used for cross-section measurements. The main results of the first measurement campaigns are presented. Preliminary results of capture cross-section measurements of minor actinides, important to ADS project for nuclear waste transmutation, are finally discussed.
ZZ AIRFEWG, Gamma, Neutron Transport Calculation in Air Using FEWG1 Cross-Section
International Nuclear Information System (INIS)
1985-01-01
1 - Description of program or function: Format: ANISN; Number of groups: 37 neutron / 21 gamma-ray; Nuclides: air (79% N and 21% O); Origin: DLC-0031/FEWG1 cross sections (ENDF/B-IV). Weighting spectrum: 1/E. The AIRFEWG library has been generated by an ANISN multigroup calculation of gamma-ray, neutron, and secondary gamma-ray transport in infinite homogeneous air using DLC-0031/FEWG1 cross sections. 2 - Method of solution: The results were generated with a P3, ANISN run with a source in a single energy group. Thus, 58 such runs were required. For sources in the 37 neutron groups, both neutron and secondary gamma-ray fluence results were calculated. For gamma-ray sources only gamma-ray fluences were calculated
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
International Nuclear Information System (INIS)
Cacuci, D.G.
1978-01-01
Some aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. In deriving these formulas, use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were greatly aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation, via FORMAC, of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u -5 . The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, is one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M 2 (u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
International Nuclear Information System (INIS)
Cacuci, D.G.
1978-04-01
Aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann Equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. Use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u -5 . The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, represent one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M 2 (u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table
Analytical calculations of neutron slowing down and transport in the constant-cross-section problem
Energy Technology Data Exchange (ETDEWEB)
Cacuci, D.G.
1978-04-01
Aspects of the problem of neutron slowing down and transport in an infinite medium consisting of a single nuclide that scatters elastically and isotropically and has energy-independent cross sections were investigated. The method of singular eigenfunctions was applied to the Boltzmann Equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. A new sufficient condition for the convergence of the coefficients of the expansion of the scattering kernel in Legendre polynomials was rigorously derived for this energy-dependent problem. Formulas were obtained for the lethargy-dependent spatial moments of the scalar flux that are valid for medium to large lethargies. Use was made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations were aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use was also made of the methods of combinatorial analysis and of computer evaluation of complicated sequences of manipulations. For the case of no absorption it was possible to obtain for materials of any atomic weight explicit corrections to the age-theory formulas for the spatial moments M/sub 2n/(u) of the scalar flux that are valid through terms of the order of u/sup -5/. The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, represent one of the end products of this investigation. In addition, an exact expression for the second spatial moment, M/sub 2/(u), valid for arbitrary (constant) absorption, was derived. It is now possible to calculate analytically and rigorously the ''age'' for the constant-cross-section problem for arbitrary (constant) absorption and nuclear mass. 5 figures, 1 table.
The CERN n_TOF Facility: Neutron Beams Performances for Cross Section Measurements
Chiaveri, E; Andrzejewski, J; Audouin, L; Barbagallo, M; Bécares, V; Bečvář, F; Belloni, F; Berthoumieux, E; Billowes, J; Boccone, V; Bosnar, D; Brugger, M; Calviani, M; Calviño, F; Cano-Ott, D; Carrapiço, C; Cerutti, F; Chin, M; Colonna, N; Cortés, G; Cortés-Giraldo, M A; Diakaki, M; Domingo-Pardo, C; Duran, I; Dressler, R; Dzysiuk, N; Eleftheriadis, C; Ferrari, A; Fraval, K; Ganesan, S; García, A R; Giubrone, G; Gómez-Hornillos, M B; Gonçalves, I F; González-Romero, E; Griesmayer, E; Guerrero, C; Gunsing, F; Gurusamy, P; Hernández-Prieto, A; Jenkins, D G; Jericha, E; Kadi, Y; Käppeler, F; Karadimos, D; Kivel, N; Koehler, P; Kokkoris, M; Krtička, M; Kroll, J; Lampoudis, C; Langer, C; Leal-Cidoncha, E; Lederer, C; Leeb, H; Leong, L S; Losito, R; Mallick, A; Manousos, A; Marganiec, J; Martínez, T; Massimi, C; Mastinu, P F; Mastromarco, M; Meaze, M; Mendoza, E; Mengoni, A; Milazzo, P M; Mingrone, F; Mirea, M; Mondalaers, W; Paradela, C; Pavlik, A; Perkowski, J; Plompen, A; Praena, J; Quesada, J M; Rauscher, T; Reifarth, R; Riego, A; Robles, M S; Roman, F; Rubbia, C; Sabaté-Gilarte, M; Sarmento, R; Saxena, A; Schillebeeckx, P; Schmidt, S; Schumann, D; Tagliente, G; Tain, J L; Tarrío, D; Tassan-Got, L; Tsinganis, A; Valenta, S; Vannini, G; Variale, V; Vaz, P; Ventura, A; Versaci, R; Vermeulen, M J; Vlachoudis, V; Vlastou, R; Wallner, A; Ware, T; Weigand, M; Weiss, C; Wright, T; Žugec, P
2014-01-01
This paper presents the characteristics of the existing CERN n\\_TOF neutron beam facility (n\\_TOF-EAR1 with a flight path of 185 meters) and the future one (n\\_TOF EAR-2 with a flight path of 19 meters), which will operate in parallel from Summer 2014. The new neutron beam will provide a 25 times higher neutron flux delivered in 10 times shorter neutron pulses, thus offering more powerful capabilities for measuring small mass, low cross section and/or high activity samples.
International Nuclear Information System (INIS)
Avdic, S.; Pesic, M.
1992-01-01
The ORTEC 580 Neutron Spectrometer system contains a detector unit in diode coincidence arrangement for measurement of fast neutron spectrum in the energy range from 1 MeV to 14 MeV. Numerical code HE3 for computation of semiconductor 3 He detector efficiency in a collimated neutron beam is based on analytical method in infinite diode approximation and Monte Carlo method for real spectrometer geometry. Calculations are performed in the first collision approximation in the detector active volume including evaluation of correction factors. Accuracy of relative detector efficiency calculation is improved by using neutron cross section from nuclear library ENDF/B-6. (author)
Cross-section of single-crystal materials used as thermal neutron filters
International Nuclear Information System (INIS)
Adib, M.
2005-01-01
Transmission properties of several single crystal materials important for neutron scattering instrumentation are presented. A computer codes are developed which permit the calculation of thermal diffuse and Bragg-scattering cross-sections of silicon., and sapphire as a function of material's constants, temperature and neutron energy, E, in the range 0.1 MeV .A discussion of the use of their single-crystal as a thermal neutron filter in terms of the optimum crystal thickness, mosaic spread, temperature, cutting plane and tuning for efficient transmission of thermal-reactor neutrons is given
Testing of the IRDF-90 cross-section library in benchmark neutron spectra
International Nuclear Information System (INIS)
Nolthenius, H.J.; Zsolnay, E.M.; Szondi, E.J.
1993-09-01
The new version of the International Reactor Dosimetry File IRDF-90 (called ''Version April 1993'') has been tested by calculation of average cross-sections and their uncertainties in a coarse three energy group structure and by neutron spectrum adjustments in reference neutron spectra. This paper presents the results obtained and compares them with the corresponding ones of the old IRDF-85 and with the data of the Nuclear Data Guide for Reactor Neutron Metrology. The applicability of the new library in the field of neutron metrology is discussed. (orig.)
14.2 MeV neutron induced U-235 fission cross section measurement
International Nuclear Information System (INIS)
Li Jingwen; Shen Guanren; Ye Zongyuan; Li Anli; Zhou Shuhua; Sun Zhongfan; Wu Jingxia; Huang Tanzi
1986-01-01
The cross section of U-235 fission induced by 14.2 MeV neutrons was measured by the time correlated associated particle method. The result obtained is (2.078+-0.040) barn. Comparison with other author's is also given. (author)
Calculation of neutron cross sections on iron up to 40 MeV
International Nuclear Information System (INIS)
Arthur, E.D.; Young, P.G.
1980-01-01
The development of high energy d + Li neutron sources for fusion materials radiation damage studies will require neutron cross sections up to 40 MeV. Experimental data above 15 MeV are generally sparse or nonexistent, and reliance must be placed upon nuclear-model calculations to produce the needed cross sections. To satisfy such requirements for the Fusion Materials Irradiation Test Facility (FMIT), neutron cross sections have been calculated for 54 56 Fe between 3 and 40 MeV. These results were joined to the existing ENDF/B-V evaluation below 3 MeV. In this energy range, most neutron reactions can be described using the Hauser-Feshbach statistical model with corrections for preequilibrium and direct-reaction effects. To properly use these models to obtain realistic cross sections, emphasis must be placed upon the determination of suitable input parameters (optical model sets, gamma-ray strength functions, level densities) valid over the energy range of the calculation. To do this, several types of independent data were used to arrive at consistent parameter sets as described
Contribution to the study of the unresolved resonance range of the neutrons cross sections
International Nuclear Information System (INIS)
Noguere, Gilles
2014-01-01
This document presents the statistical description of neutron cross sections in the unresolved resonance range. The modeling of the total cross section and of the 'shape - elastic' cross section is based on the 'average R-Matrix' formalism. The partial cross sections describing the radiative capture, elastic scattering, inelastic scattering and fission process are calculated using the Hauser-Feshbach formalism with width fluctuation corrections. In the unresolved resonance range, these models depend on the average resonance parameters (neutron strength function Sc, mean level spacing D c , average partial reaction widths Γ c , channel radius a c , effective radius R' and distant level parameter R-bar c ∞ ). The codes (NJOY, CALENDF...) dedicated to the processing of nuclear data libraries (JEFF, ENDF/B, JENDL, CENDL, BROND... ) use the average parameters to take into account the self-shielding phenomenon for the simulation of the neutron transport in Monte-Carlo (MCNP, TRIPOLI... ) and deterministic (APOLLO, ERANOS...) codes. The evaluation work consists in establishing a consistent set of average parameters as a function of the total angular momentum J of the system and of the orbital moment of the incident neutron l. The work presented in this paper aims to describe the links between the S-Matrix and the 'average R-Matrix' formalism for the calculation of Sc, R-bar c ∞ , ac and R'. (author) [fr
HADES. A computer code for fast neutron cross section from the Optical Model
International Nuclear Information System (INIS)
Guasp, J.; Navarro, C.
1973-01-01
A FORTRAN V computer code for UNIVAC 1108/6 using a local Optical Model with spin-orbit interaction is described. The code calculates fast neutron cross sections, angular distribution, and Legendre moments for heavy and intermediate spherical nuclei. It allows for the possibility of automatic variation of potential parameters for experimental data fitting. (Author) 55 refs
Estimation of 242Cm neutron cross sections for total file creation
International Nuclear Information System (INIS)
Bakhanovich, L.A.; Klepatskij, A.B.; Maslov, V.M.; Porodzinskij, Yu.V.; Sukhovitskij, E.Sh.
1989-01-01
Description of evaluation of 242 Cm neutron cross sections in 10 -5 eV-20 MeV energy range is given. Due to the lack of experimental data the evaluation is largely based on the application of theoretical models and systematics. The data obtained are compared to evaluations by other authors. 10 refs.; 2 figs.; 2 tabs
International Nuclear Information System (INIS)
Ganesan, S.; Pashchenko, A.B.; Lemmle, H.D.; Mann, F.M.
1994-01-01
This document summarises a neutron activation cross-section database which has been processed in two formats for input to MCNP Monte Carlo codes and to REAC transmutation codes. The data are available from the IAEA Nuclear Data Section online via INTERNET by FTP command. (author)
An exact formalism for Doppler-broadened neutron cross-sections
International Nuclear Information System (INIS)
Catsaros, Nicolas.
1985-07-01
An exact formalism (Ψ, Φ) is proposed for the calculation of Breit-Wigner or Adler-Adler Doppler-broadened neutron cross-sections. The well-known (Ψ, Φ) formalism is shown to be a zero-order approximation of the generalized (Ψ, Φ) formalism. (author)
International Nuclear Information System (INIS)
James, G.D.
1976-01-01
A review of the status of transactinium isotope cross sections in the resonance region and of resolved resonance parameters is given by summarising the work submitted by fourteen contributors and also by highlighting other work where notable progress has been made in our knowledge of neutron resonance phenomena. (author)
Library of neutron reaction cross-sections in the ABBN-93 constant system
International Nuclear Information System (INIS)
Zabrodskaya, S.V.; Korchagina, Zh.A.; Koshcheev, V.N.; Nikolaev, M.N.; Tsibulya, A.M.
2001-01-01
The library of neutron reaction group cross-sections in the ABBN-93 constant set is described. The format used for data representation, the content and purpose of the sub-libraries and their practical application in the SCALE criticality safety estimation system are discussed. (author)
Comparison of neutron scattering cross sections with the JLM microscopic optical model
International Nuclear Information System (INIS)
Kailas, S.; Gupta, S.K.
Recently Jeukenne et al have determined microscopically the nucleon-nucleus optical potential from Reid's nucleon-nucleon interaction. Microscopic neutron-nucleus optical potentials are constructed using accurate matter densities. Reasonable success has been obtained in describing the total and elastic cross section and angular distributions at Esub(n)=8.05 MeV without modifying the microscopically calculated potentials. (auth.)
International Nuclear Information System (INIS)
Van'kov, A.A.
1994-01-01
The contradiction between a measured integral neutron absorption cross-section averaged over a fast reactor spectrum and the corresponding value which was calculated with the use of evaluated microscopic cross-sections and a theoretical neutron spectrum has been investigated. The possible systematic error of a correction factor which takes into account multiple resonance neutron scattering in samples used in the measurement of the absorption cross-section is investigated. It is proposed that this error may be one of the main reason for the contradiction mentioned above which arises in the measurement of the 236 U neutron absorption cross-section. (author). 13 refs, 3 figs
Removal cross section for 14 MeV neutrons in constructional materials
International Nuclear Information System (INIS)
Vasvary, L.; Divos, F.; Peto, G.; Csikai, J.; Mumba, N.K.
1986-01-01
Using flight time difference the direct and scattered neutrons and gammas produced in the target head and samples were separated. With this method the attenuation of primary neutrons and gammas originating from the target head has been studied. Thickness dependence of the secondary gamma yield from extended samples of Al, Fe, Pb, paraffin and reinforced concrete was also measured. Results indicate a geometry dependence of the removal cross sections. (author)
TEMPEST-2, Thermalization Program for Neutron Spectra and Multigroup Cross-Sections
International Nuclear Information System (INIS)
Gowins, G.
1984-01-01
Description of problem or function: TEMPEST2 is a neutron thermalization program based upon the Wigner-Wilkins approximation for light moderators and the Wilkins approximation for heavy moderators. A Maxwellian distribution may also be used. The model used may be selected as a function of energy. The second-order differential equations are integrated directly rather than transformed to the Riccati equation. The program provides microscopic and macroscopic cross-section averages over the thermal neutron spectrum
Comparison of Neutron Cross-Sections Using IAEA Nuclear Codes ''ABAREX'' and ''SCAT2''
International Nuclear Information System (INIS)
Myint Myint Moe; Win Sin; Sein Htoon
2004-05-01
Moel calculations can be used to provide nuclear data for applications in science and technology. The energy averaged neutron induced nuclear reaction cross-sections particular for Al-27, Mg-24, Cr-52, Mn-55, Zn-64 and U-238 with neutrons of energy (0.005 to 10 MeV) are calculated using IAEA nuclear codes ''ABAREX'' and ''SCAT2''. The results are compared with those given in ENDF- 3 nuclear data
Secondary neutron double differential cross sections from 209Bi at 14.2 MeV
International Nuclear Information System (INIS)
Shen Guanren; Xia Haihong; Tang Hongqing
1992-01-01
The secondary neutron double differential cross sections from 209 Bi at 14.2 MeV have been measured at 6 angles between 25 degree-150 degree using an associated particle TOF spectrometer. Flight path was 2.7 m. The neutron detector was biased at 1.3 MeV. The time resolution was about 1.2 ns. The data were compared with existing data and theoretical calculated results. Good agreement is achieved
Measurement of photon production cross sections with the ATLAS detector
Turra, Ruggero; The ATLAS collaboration
2017-01-01
The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the proton structure. The ATLAS Collaboration has performed precise measurements of the inclusive production of isolated prompt photons at a centre-of-mass energy of 13 TeV, differential in both rapidity and photon transverse momentum. In addition, the integrated and differential cross sections for isolated photon pairs at 8 TeV have been measured. The results are compared with state-of-the-art theory predictions at NLO in QCD and with predictions of several MC generators. The production of prompt photons in association with jets provides an additional testing ground for perturbative QCD (pQCD) with a hard colourless probe less affected by hadronisation effects than jet production. The dynamics of isolated-photon plus jet production in pp collisions at a centre-of-mass energy of 8 and 13 TeV will be presented and discussed.
New evaluated neutron cross section libraries for the GEANT4 code
International Nuclear Information System (INIS)
Mendoza, E.; Cano-Ott, D.; Guerrero, C.; Capote, R.
2012-04-01
The so-called High Precision neutron physics model implemented in the GEANT4 simulation package allows simulating the transport of neutrons with energies up to 20 MeV. It relies on the G4NDL cross section libraries, prepared by the GEANT4 collaboration from evaluated cross section files and distributed freely together with the code. Even though the performance of the G4NDL library has been improved over the time, users running complex simulations which involve the transport of neutrons do need more flexibility, in particular when assessing the uncertainties in the simulation results due to the neutron (and hence the nuclear) data library used. For this reason, a software tool has been developed for transforming any evaluated neutron cross section library in the ENDF-6 format into the G4NDL format. Furthermore, eight different releases of ENDF-B, JEFF, JENDL, CENDL and BROND national libraries have been translated into the G4NDL format and are distributed by the IAEA nuclear data service at www-nds.iaea.org/geant4. In this way, GEANT4 users have access to the complete list of standard evaluated neutron data libraries when performing Monte Carlo simulations with GEANT4. Consistency checks and a first validation of the libraries have been made following the methods described in this report. (author)
On unambiguous parametrization of neutron cross-sections in the low-energy region
International Nuclear Information System (INIS)
Novoselov, G.M.; Kolomiets, V.M.
1982-08-01
One of the most important aims of analysis in the resonance region is the evaluation of neutron resonance parameters on the basis of a given formalism of the theory of nuclear reactions. However, the task of finding resonance parameters from experimental data on the energy dependence of cross-sections is subject to a number of difficulties. These difficulties are not only of a theoretical character associated with the selection of one version or another of the theory taking into account the effects necessary (interference between resonances, Doppler effect etc.), but also involve problems of principle. Whether the set of parameters found is the only possible one within the context of a single formalism used remains open. The specific features of processing the experimental data are such that even with good resolution a number of overlapping resonances (occurring as a result of the fluctuation in inter-level distances or the Doppler effect) may be classified as an isolated resonance. Moreover, even given a very weak inter-level interference and Doppler effect, unambiguous parametrization of the cross-sections is not always possible. In the present paper these questions (the choice of the approximation needed for describing experimentally observed cross-sections, allowance for inter-level interference and the Doppler effect and the possibility of ambiguous reproduction of the resonance structure of cross-sections) are examined with reference to the parametrization of the total cross-sections for non-fissionable nuclei in the low-neutron-energy region
International Nuclear Information System (INIS)
Gerstl, S.A.W.; LaBauve, R.J.; Young, P.G.
1980-05-01
On the example of General Atomic's well-documented Power Generating Fusion Reactor (PGFR) design, this report exercises a comprehensive neutron cross-section and secondary energy distribution (SED) uncertainty analysis. The LASL sensitivity and uncertainty analysis code SENSIT is used to calculate reaction cross-section sensitivity profiles and integral SED sensitivity coefficients. These are then folded with covariance matrices and integral SED uncertainties to obtain the resulting uncertainties of three calculated neutronics design parameters: two critical radiation damage rates and a nuclear heating rate. The report documents the first sensitivity-based data uncertainty analysis, which incorporates a quantitative treatment of the effects of SED uncertainties. The results demonstrate quantitatively that the ENDF/B-V cross-section data files for C, H, and O, including their SED data, are fully adequate for this design application, while the data for Fe and Ni are at best marginally adequate because they give rise to response uncertainties up to 25%. Much higher response uncertainties are caused by cross-section and SED data uncertainties in Cu (26 to 45%), tungsten (24 to 54%), and Cr (up to 98%). Specific recommendations are given for re-evaluations of certain reaction cross-sections, secondary energy distributions, and uncertainty estimates
Measurement of fast neutron induced fission cross section of minor-actinide
International Nuclear Information System (INIS)
Hirakawa, Naohiro
1997-03-01
In fuel cycles with recycled actinide, core characteristics are largely influenced by minor actinide (MA: Np, Am, Cm). Accurate nuclear data of MA such as fission cross section are required to estimate the effect of MA with high accuracy. In this study, fast neutron induced fission cross section of MA is measured using Dynamitron Accelerator in Tohoku University. The experimental method and the samples, which were developed or introduced during the last year, were improved in this fiscal year: (1) Development of a sealed fission chamber, (2) Intensification of Li neutron target, (3) Improvement of time-resolution of Time-of-Flight (TOF) electronic circuit, (4) Introduction of Np237 samples with large sample mass and (5) Introduction of a U235 sample with high purity. Using these improved tools and samples, the fission cross section ratio of Np237 relative to U235 was measured between 5 to 100 keV, and the fission cross section of Np237 was deduced. On the other hand, samples of Am241 and Am243 were obtained from Japan Atomic Energy Research Institute (JAERI) after investigating fission cross section of two americium isotopes (Am241 and Am 243) which are important for core physics calculation of fast reactors. (author)
Iwamoto, Yosuke; Hagiwara, Masayuki; Matsumoto, Tetsuro; Masuda, Akihiko; Iwase, Hiroshi; Yashima, Hiroshi; Shima, Tatsushi; Tamii, Atsushi; Nakamura, Takashi
2012-10-01
Secondary neutron-production double-differential cross-sections (DDXs) have been measured from interactions of 137 MeV and 200 MeV protons in a natural carbon target. The data were measured between 0° and 25° in the laboratory. DDXs were obtained with high energy resolution in the energy region from 3 MeV up to the maximum energy. The experimental data of 137 MeV protons at 10° and 25° were in good agreement with that of 113 MeV protons at 7.5° and 30° at LANSCE/WNR in the energy region below 80 MeV. Benchmark calculations were carried out with the PHITS code using the evaluated nuclear data files of JENDL/HE-2007 and ENDF/B-VII, and the theoretical models of Bertini-GEM and ISOBAR-GEM. For the 137 MeV proton incidence, calculations using JENDL/HE-2007 generally reproduced the shape and the intensity of experimental spectra well including the ground state of the 12N state produced by the 12C(p,n)12N reaction. For the 200 MeV proton incidence, all calculated results underestimated the experimental data by the factor of two except for the calculated result using ISOBAR model. ISOBAR predicts the nucleon emission to the forward angles qualitatively better than the Bertini model. These experimental data will be useful to evaluate the carbon data and as benchmark data for investigating the validity of the Monte Carlo simulation for the shielding design of accelerator facilities.
Thermal neutron capture and resonance integral cross sections of {sup 45}Sc
Energy Technology Data Exchange (ETDEWEB)
Van Do, Nguyen; Duc Khue, Pham; Tien Thanh, Kim [Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Hanoi (Viet Nam); Thi Hien, Nguyen [Institute of Physics, Vietnam Academy of Science and Technology, 10 Dao Tan, Hanoi (Viet Nam); Department of Physics and Center for High Energy Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Guinyun, E-mail: gnkim@knu.ac.kr [Department of Physics and Center for High Energy Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, Kwangsoo [Department of Physics and Center for High Energy Physics, Kyungpook National University, Daegu 702-701 (Korea, Republic of); Shin, Sung-Gyun; Cho, Moo-Hyun [Department of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Lee, Manwoo [Research Center, Dongnam Institute of Radiological and Medical Science, Busan 619-953 (Korea, Republic of)
2015-11-01
The thermal neutron cross section (σ{sub 0}) and resonance integral (I{sub 0}) of the {sup 45}Sc(n,γ){sup 46}Sc reaction have been measured relative to that of the {sup 197}Au(n,γ){sup 198}Au reaction by means of the activation method. High-purity natural scandium and gold foils without and with a cadmium cover of 0.5 mm thickness were irradiated with moderated pulsed neutrons produced from the Pohang Neutron Facility (PNF). The induced activities in the activated foils were measured with a high purity germanium (HPGe) detector. In order to improve the accuracy of the experimental results the counting losses caused by the thermal (G{sub th}) and resonance (G{sub epi}) neutron self-shielding, the γ-ray attenuation (F{sub g}) and the true γ-ray coincidence summing effects were made. In addition, the effect of non-ideal epithermal spectrum was also taken into account by determining the neutron spectrum shape factor (α). The thermal neutron cross-section and resonance integral of the {sup 45}Sc(n,γ){sup 46}Sc reaction have been determined relative to the reference values of the {sup 197}Au(n,γ){sup 198}Au reaction, with σ{sub o,Au} = 98.65 ± 0.09 barn and I{sub o,Au} = 1550 ± 28 barn. The present thermal neutron cross section has been determined to be σ{sub o,Sc} = 27.5 ± 0.8 barn. According to the definition of cadmium cut-off energy at 0.55 eV, the present resonance integral cross section has been determined to be I{sub o,Sc} = 12.4 ± 0.7 barn. The present results are compared with literature values and discussed.
Abbondanno, U; Alvarez-Velarde, F; Alvarez-Pol, H; Andriamonje, Samuel A; Andrzejewski, J; Badurek, G; Baumann, P; Becvar, F; Benlliure, J; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Cennini, P; Chepel, V; Chiaveri, Enrico; Colonna, N; Cortés, G; Cortina-Gil, D; Couture, A; Cox, J; Dababneh, S; Dahlfors, M; David, S; Dolfini, R; Domingo-Pardo, C; Durán, I; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Kölbl, H; Furman, W; Gonçalves, I; Gallino, R; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martínez, A; Isaev, S; Jericha, E; Kappeler, F; Kadi, Y; Karadimos, D; Kerveno, M; Ketlerov, V; Köhler, P; Konovalov, V; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez-Val, J; Mastinu, P; Mengoni, A; Milazzo, P M; Molina-Coballes, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, Heinz; O'Brien, S; Pancin, J; Papaevangelou, T; Paradela, C; Pavlik, A; Pavlopoulos, P; Perlado, J M; Perrot, L; Pignatari, M; Plag, R; Plompen, A; Plukis, A; Poch, A; Policarpo, Armando; Pretel, C; Quesada, J; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, Carlo; Rudolf, G; Rullhusen, P; Salgado, J; Soares, J C; Stéphan, C; Tagliente, G; Taín, J L; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarín, D; Vincente, M C; Vlachoudis, V; Voss, F; Wendler, H; Wiescher, M; Wissha, K
2004-01-01
The measurement of **1**5**1Sm(n, gamma)**1**5**2Sm (samarium) cross section showed improved performance of the new spallation neutron facility. It covered a wide energy range with good resolution, high neutron flux, low backgrounds and a favourable duty factor. The samarium cross section was found to be of great importance for characterizing neutron capture nucleosynthesis in asymptotic giant stars. The combination of these features provided a promising basis for a broad experimental program directed towards application in astrophysics and advanced nuclear technologies. (Edited abstract)
International Nuclear Information System (INIS)
Smith, L.A.; Gehin, J.C.; Worley, B.A.; Renier, J.P.
1994-01-01
The FOEHN critical experiments were analyzed to validate the use of multigroup cross sections in the design of the Advanced Neutron Source. Eleven critical configurations were evaluated using the KENO, DORT, and VENTURE neutronics codes. Eigenvalue and power density profiles were computed and show very good agreement with measured values
International Nuclear Information System (INIS)
Chernukhin, Yu.G.; Kandiev, Ya.Z.; Lartsev, V.D.; Levakov, B.G.; Modestov, D.G.; Simonenko, V.A.; Streltsov, S.I.; Khmel'nitskij, D.V.
2006-01-01
The main stage of experiment for direct measurement of cross section of neutron-neutron scattering σ nn at low energies (E nn determination. It was shown, that for achieving the criterion ε ∼ 4% it will be necessary to have 40-50 pulses of a reactor [ru
ZZ DOSCROS, Neutron Cross-Section Library for Spectra Unfolding and Integral Parameter Evaluation
International Nuclear Information System (INIS)
Zijp, Willem L.; Nolthenius, Henk J.; Rieffe, Henk Ch.
1987-01-01
1 - Description of problem or function: Format: SAND-II; Number of groups: 640 fine group cross section values; Nuclides: Li, B, F, Na, Mg, Al, S, Sc, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Nb, Mo, Rh, Pd, Ag, In, Sb, I, Cs, La, Eu, Sm, Dy, Lu, Ta, W, Re, Au, Th, U, Np, Pu. Origin: ENDF/B-V mainly, ENDF/B-IV, INDL/V. This library forms in combination with the DAMSIG81 library a convenient source of evaluated energy dependent cross section sets which may be used in the determination of neutron spectra by means of adjustment (or unfolding) procedures or which can be used for the determination of integral parameters (such as damage-to-activation ratio) useful in characterising the neutron spectra. The energy dependent fine group cross section data are presented in a 640 group structure of the SAND-II type. This group structure has 45 energy groups per energy decade below 1 MeV and a group width of 100 KeV above 1 MeV. The total energy span of this group structure is from 10 -10 MeV to 20 MeV. The library has the SAND-II format, which implies that a special part of the library has to contain cover cross section data sets. These cross section data sets are required in the SAND-II program for taking into account the influence of special detector surroundings which may be used during an irradiation. 2 - Method of solution: The selection of the reactions from the evaluated nuclear data libraries was determined by various properties of the reactions for neutron metrology. For this reason all the well- known reactions of the ENDF/B-V dosimetry file are included but these data are supplemented with cross section sets for less well known metrology reactions which may become of interest
Fast-neutron total and elastic-scattering cross sections of elemental indium
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-11-01
Broad-resolution neutron total cross sections of elemental indium were measured from 0.8 to 4.5 MeV. Differential-elastic-scattering cross sections were measured from approx. = 1.5 to 3.8 MeV at intervals of approx. = 50 to 200 keV and at scattering angles in the range 20 to 160 degrees. The experimental results are interpreted in terms of the optical-statistical model and are compared with respective values given in ENDF/B-V
Neutron capture cross section of $^{25}$Mg and its astrophysical implications
We propose to measure the neutron capture cross section of the stable $^{25}$Mg isotope. This experiment aims at the improvement of existing results for nuclear astrophysics.The measurement will be carried out under similar conditions as for the Mgexperiment that was completed at n_TOF during 2003. A metal $^{25}$Mg-enriched sample will be used in the proposed experiment instead of a MgO powder sample, which was used in the previous measurement and prevented us to minimize the uncertainty of the measured cross section. This experiment will be part of an ongoing study for a comprehensive discussion of the s-process abundances in massive stars.
Measurements of neutron-deuteron breakup cross sections at 13.0 MeV
International Nuclear Information System (INIS)
Setze, H.R.; Howell, C.R.; Tornow, W.
1993-01-01
The discrepancy between low-energy nucleon-deuteron breakup cross-section data and calculations, which do not include three-nucleon forces, has been cited as a possible signature of the influence of three-nucleon forces section. The comparison between data and calculations is difficult to interpret because there are significant disagreements between the data. To help clarify the situation we have made kinematically complete cross-section measurements for n-d breakup at an incident neutron energy of 13.0 MeV. The experimental techniques and data analysis method will be described. Preliminary results will be presented in comparison to calculations and previous data
Rosenbluth separation of the $\\pi^0$ Electroproduction Cross Section off the Neutron
Mazouz, M.; Ahmed, Z.; Albataineh, H.; Allada, K.; Aniol, K. A.; Bellini, V.; Benali, M.; Boeglin, W.; Bertin, P.; Brossard, M.; Camsonne, A.; Canan, M.; Chandavar, S.; Chen, C.; Chen, J. -P.
2017-01-01
We report the first longitudinal/transverse separation of the deeply virtual exclusive $\\pi^0$ electroproduction cross section off the neutron and coherent deuteron. The corresponding four structure functions $d\\sigma_L/dt$, $d\\sigma_T/dt$, $d\\sigma_{LT}/dt$ and $d\\sigma_{TT}/dt$ are extracted as a function of the momentum transfer to the recoil system at $Q^2$=1.75 GeV$^2$ and $x_B$=0.36. The $ed \\to ed\\pi^0$ cross sections are found compatible with the small values expected from theoretical...
Voyles, A. S.; Basunia, M. S.; Batchelder, J. C.; Bauer, J. D.; Becker, T. A.; Bernstein, L. A.; Matthews, E. F.; Renne, P. R.; Rutte, D.; Unzueta, M. A.; van Bibber, K. A.
2017-11-01
Cross sections for the 47Ti(n,p)47Sc and 64Zn(n,p)64Cu reactions have been measured for quasi-monoenergetic DD neutrons produced by the UC Berkeley High Flux Neutron Generator (HFNG). The HFNG is a compact neutron generator designed as a "flux-trap" that maximizes the probability that a neutron will interact with a sample loaded into a specific, central location. The study was motivated by interest in the production of 47Sc and 64Cu as emerging medical isotopes. The cross sections were measured in ratio to the 113In(n,n‧)113mIn and 115In(n,n‧)115mIn inelastic scattering reactions on co-irradiated indium samples. Post-irradiation counting using an HPGe and LEPS detectors allowed for cross section determination to within 5% uncertainty. The 64Zn(n,p)64Cu cross section for 2.76-0.02+0.01 MeV neutrons is reported as 49.3 ± 2.6 mb (relative to 113In) or 46.4 ± 1.7 mb (relative to 115In), and the 47Ti(n,p)47Sc cross section is reported as 26.26 ± 0.82 mb. The measured cross sections are found to be in good agreement with existing measured values but with lower uncertainty (neutron sources for nuclear data measurements and potentially the production of radionuclides for medical applications.
Habit, Production, and the Cross-Section of Stock Returns
Chen, Andrew Y.
2014-01-01
Solutions to the equity premium puzzle should inform us about the cross-section of stock returns. An external habit model with heterogeneous firms reproduces numerous stylized facts about both the equity premium and the value premium. The equity premium is large, time-varying, and linked with consumption volatility. The cross-section of expected returns is log-linear in B/M, and the slope matches the data. The explanation for the value premium lies in the interaction between the cross-section...
Villaplana Perez, Miguel; The ATLAS collaboration
2017-01-01
The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the proton structure. The ATLAS collaboration has performed precise measurements of the inclusive production of isolated prompt photons at a centre-of-mass energy of 13 TeV, differential in both rapidity and the photon transverse momentum. In addition, the integrated and differential cross sections for isolated photon pairs and tri-photon production 8 TeV have been measured. The results are compared with state-of-the-art theory predictions at NLO in QCD and with predictions of several MC generators. The production of prompt photons in association with jets provides an additional testing ground for perturbative QCD (pQCD) with a hard colourless probe less affected by hadronisation effects than jet production. The ATLAS collaboration has studied the dynamics of isolated-photon production in association with gluon, light and heavy quark final states in pp collisions at a centre-of-...
Cross sections for d-{sup 3}H neutron interactions with samarium isotopes
Energy Technology Data Exchange (ETDEWEB)
Luo, Junhua; He, Long [Hexi Univ., Zhangye (China). School of Physics and Electromechanical Engineering; Wu, Chunlei; Jiang, Li [Chinese Academy of Engineering Physics, Mianyang (China). Inst. of Nuclear Physics and Chemistry
2016-11-01
The cross sections for (n,x) reactions on samarium isotopes were measured at (d-T) neutron energies of 13.5 and 14.8 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Theoretical calculations of excitation functions were performed using the nuclear model codes TALYS-1.6 and EMPIRE-3.2 Malta with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature. At neutron energies 13.5 and 14.8 MeV, the cross sections of the {sup 149}Sm(n,p){sup 149}Pm reaction are reported for the first time. The cross sections of the {sup 150}Sm(n,p){sup 150}Pm, {sup 144}Sm(n,p){sup 144}Pm, {sup 152}Sm(n,α){sup 149}Nd and {sup 144}Sm(n,α){sup 141}Nd reactions at different neutron energies reported in the present work can be added as new data in the nuclear databases.
Cross sections for D-T neutron interaction with neodymium isotopes
International Nuclear Information System (INIS)
Luo, Junhua; An, Li; Jiang, Li; He, Long
2015-01-01
The cross-sections for (n, x) reactions with neodymium isotopes were measured at (D-T) neutron energies around 14 MeV with the activation technique. Samples were activated along with Nb and Al monitor foils to determine the incident neutron flux. Data are reported for the following reactions: 142 Nd(n,2n) 141 Nd, 148 Nd(n,2n) 147 Nd, 150 Nd(n,2n) 149 Nd, 142 Nd(n,p) 142 Pr, 146 Nd(n,α) 143 Ce, and 146 Nd(n,p) 146 Pr. Theoretical calculations of excitation functions were performed with the TALYS-1.6 nuclear model code, at neutron energies varying from the reaction threshold to 20 MeV. The results were discussed and compared with experimental data found in the literature, and with the comprehensive evaluation data in ENDF/B-VII.1, JENDL-4.0, and CENDL-3 libraries. - Highlights: • The cross sections for the (n,x) reactions on Neodymium have been measured. • Mono-energetic neutron beams using the D-T reaction; Energies: 13.5–14.8 MeV. • Neutron cross-section measurements by means of the activation technique. • Reference reactions 93 Nb(n,2n) 92m Nb and 27 (n, α) 24 Na were used as the monitor. • Nuclear reaction code TALYS-1.6 was used
Energy Technology Data Exchange (ETDEWEB)
Abramo; vich, S.N.; Andreev, M.F.; Bol`shakov, Y.M. [Institute of Experimental Physics, Arzamas (Russian Federation)] [and others
1995-10-01
Measurements have been carried out of {sup 238}Np fission cross-section by thermal neutrons. The isotope {sup 238}Np was built up through the reaction {sup 238}U(p,n) on an electrostatic accelerator. Extraction and cleaning of the sample were done by ion-exchange chromatography. Fast neutrons were generated on the electrostatic accelerator through the reaction {sup 9}Be(d,n); a polyethylene block was used to slow down neutrons. Registration of fission fragments was performed with dielectric track detectors. Suggesting that the behavior of {sup 238}Np and {sup 238}U. Westscott`s factors are indentical the fission cross-section of {sup 238}Np was obtained: {sigma}{sub fo}=2110 {plus_minus} 75 barn.
International Nuclear Information System (INIS)
Adib, M.; Abdel-Kawy, A.; Maayouf, R.M.A.; Fayek, M.; Mostafa, M.; Hamouda, I.
1981-09-01
Total neutron cross-section measurements have been performed for natural Nb at liquid nitrogen, room and 425 0 K temperatures in the energy range from 2 MeV - 1 eV. The measurements were performed using two time-of-flight spectrometers installed in front of two of the ET-RR-1 reactor horizontal channels. The neutron diffraction pattern of Nb, at room temperature, was obtained using a double axis crystal spectrometer installed also at the ET-RR-1 reactor. The obtained total neutron cross-sections were analyzed using the single level Breit-Wigner formula. The coherent scattering amplitude was determined from the Bragg reflections observed in the total neutron cross-section of Nb and the analysis of its neutron diffraction pattern. The incoherent and thermal inelastic scattering cross-sections of Nb were determined from the analysis of the total cross-section of Nb beyond the cut-off wavelength. The following results have been obtained: sigmasub(t) = (6.30+-0.20)b; sigmasub(coh) = (6.0+-0.3)b; sigmasub(incoh) = (2.0+-1.0)b; bsub(coh) = (6.91+-0.08)fm
High resolution neutron total and capture cross-sections in separated isotopes of copper (6365Cu)
International Nuclear Information System (INIS)
Pandey, M.S.
1975-01-01
High resolution neutron total and capture cross section measurements have been performed on separated isotopes of copper ( 63 65 Cu). Measurements for capture cross section were made from about 1 keV to a few hundreds of keV. The total cross section measurements were made in the energy interval of approximately 10 keV to 150 keV. The resulting capture data have been analyzed by a generalized least square peak fitting computer code in the energy interval of 2.5 keV to 50 keV. Photon strengths are determined using the data up to approximately 250 keV. The resulting total cross section data have been analyzed by area-analysis on the transmission values and by R-matrix multilevel code on cross section values. Average s- and p-wave level spacing and s- and p-wave strength function values are determined. From the resonance parameters thus obtained, by the analysis, statistical distribution is studied for s- and p-wave level spacings and reduced neutron widths. A comparison has been made for adjacent level spacings with the theoretical predictions of level repulsion (of same J/sup π/) by Wigner considering levels with various spin states separately for s-wave resonances where confident spin assignment has been possible. Reduced neutron widths are compared with the Porter-Thomas distribution. Optical model formulated by Feshbach, Porter and Weiskopf describes the neutron-nucleus interaction. A comparison has been made between experimentally determined values of the s- and p-wave strength functions and that obtainable from optical model calculations, thereby determining the appropriate optical model parameters. The experimental arrangement, pertinent theoretical discussion, and the processes of data reduction and the analyses along with the comparison of the previously reported results with the present work are presented in detail
Neutron slowing down and transport in a medium of constant cross section. I. Spatial moments
International Nuclear Information System (INIS)
Cacuci, D.G.; Goldstein, H.
1977-01-01
Some aspects of the problem of neutron slowing down and transport have been investigated in an infinite medium consisting of a single nuclide scattering elastically and isotropically without absorption and with energy-independent cross sections. The method of singular eigenfunctions has been applied to the Boltzmann equation governing the Laplace transform (with respect to the lethargy variable) of the neutron flux. Formulas have been obtained for the lethargy dependent spatial moments of the scalar flux applicable in the limit of large lethargy. In deriving these formulas, use has been made of the well-known connection between the spatial moments of the Laplace-transformed scalar flux and the moments of the flux in the ''eigenvalue space.'' The calculations have been greatly aided by the construction of a closed general expression for these ''eigenvalue space'' moments. Extensive use has also been made of the methods of combinatorial analysis and of computer evaluation, via FORMAC, of complicated sequences of manipulations. It has been possible to obtain for materials of any atomic weight explicit corrections to the age theory formulas for the spatial moments M/sub 2n/(u), of the scalar flux, valid through terms of order of u -5 . Higher order correction terms could be obtained at the expense of additional computer time. The evaluation of the coefficients of the powers of n, as explicit functions of the nuclear mass, represent the end product of this investigation
Measurements of integral cross sections in the californium-252 fission neutron spectrum
International Nuclear Information System (INIS)
Alberts, W.G.; Guenther, E.; Matzke, M.; Rassl, G.
1977-01-01
In a low-scattering arrangement cross sections averaged over the californium-252 spontaneous fission neutron spectrum were measured. The reactions 27 Al(n,α) 46 Ti, 47 Ti, 48 Ti(n,p), 54 Fe, 56 Fe(n,p), 58 Ni(n,p), 64 Zn(n,p), 115 In(n,n') were studied in order to obtain a consistent set of threshold detectors used in fast neutron flux density measurements. Overall uncertainties between 2 and 2.5% could be achieved; corrections due to neutron scattering in source and samples are discussed
Neutron scattering differential cross sections of carbon and bismuth at 37 MeV
International Nuclear Information System (INIS)
Zhou Zuying; Tang Hongqing; Qi Bujia; Zhou Chenwei; Du Yanfeng; Xia Haihong; Walter, R.L.; Tornow, W.; Howell, C.; Braun, R.; Roper, C.; Chen Zemin; Chen Zhengpeng; Chen Yingtang
1997-01-01
Elastic differential cross sections of 37 MeV neutrons scattered from carbon and bismuth were measured in the angular range 11 to 160 degrees by means of the multi-detector TOF facility. The 37 MeV neutrons were produced via the T(d,n) 4 He reaction in a tritium gas target. The pulsed 20 MeV deuteron beam was provided by the HI-13 tandem accelerator. The angular distribution of scattered neutrons from carbon and bismuth were measured in the angular range 11 degree to 145 degree and 11 degree to 160 degree respectively in steps of about 3 degree
Neutron total cross section measurements in the energy region from 47 keV to 20 MeV
International Nuclear Information System (INIS)
Poenitz, W.P.; Whalen, J.F.
1983-05-01
Neutron total cross sections were measured for 26 elements. Data were obtained in the energy range from 47 keV to 20 MeV for 11 elements in the range of light-mass fission products. Previously reported measurements for eight heavy and actinide isotopes were extended to 20 MeV. Data were also obtained for Cu (47 keV to 1.4 MeV) and for Sc, Zn, Nd, Hf, and Pt (1.8 to 20 MeV). The present work is part of a continuing effort to provide accurate neutron total cross sections for evaluations and for optical-model parameteriztions. The latter are required for the derivation of other nuclear-data information of importance to applied programs. 37 references
International Nuclear Information System (INIS)
Padron, I.; Dominguez, O.; Sarria, P. Sandin, C.
1996-01-01
The time -of-Flight neutron spectrometry technique by associated particle method was improved using a D-T neutron generator at Laboratory of Nuclear Analysis. This technique was implemented for double differential cross section measurements and supported by the IAEA Project CUB/01/005. An stilbene scintillation detector (dia=100 mm, length=50 mm) was used as principal neutron detector detector and was situated outside a hole in the concrete wall. This way the fligth path was extended and the scattered neutron cone accurate collimated throught the 2 m concrete wall. For the associated particle α detection a thin plastic NE-102 scint illator was used, as well as, two scintilation detectors and a long counter for the neutron flux monitoring. In this TOF neutron spectrometer (3.40 m flight path) a 1.7 nseg. temporal resolution was obtained
International Nuclear Information System (INIS)
Bosted, P. E.; Christy, M. E.
2008-01-01
An empirical fit is described to measurements of inclusive inelastic electron-deuteron cross sections in the kinematic range of four-momentum transfer 0≤Q 2 2 and final state invariant mass 1.1 p of longitudinal to transverse cross sections for the proton, and the assumption R p =R n . The underlying fit parameters describe the average cross section for a free proton and a free neutron, with a plane-wave impulse approximation used to fit to the deuteron data. Additional fit parameters are used to fill in the dip between the quasi-elastic peak and the Δ(1232) resonance. The mean deviation of data from the fit is 3%, with less than 4% of the data points deviating from the fit by more than 10%
Energy Technology Data Exchange (ETDEWEB)
Anderson, J D; Bauer, R W; Dietrich, F S; Grimes, S M; Finlay, R W; Abfalterer, W P; Bateman, F B; Haight, R C; Morgan, G L; Bauge, E; Delaroche, J P; Romain, P
2001-11-01
Recently cross section differences among the isotopes{sup 182,184,186}W have been measured as part of a study of total cross sections in the 5-560 MeV energy range. These measurements show oscillations up to 150 mb between 5 and 100 MeV. Spherical and deformed phenomenological optical potentials with typical radial and isospin dependences show very small oscillations, in disagreement with the data. In a simple Ramsauer model, this discrepancy can be traced to a cancellation between radial and isospin effects. Understanding this problem requires a more detailed model that incorporates a realistic description of the neutron and proton density distributions. This has been done with results of Hartree-Fock-Bogolyubov calculations using the Gogny force, together with a microscopic folding model employing a modification of the JLM potential as an effective interaction. This treatment yields a satisfactory interpretation of the observed total cross section differences.
Cross-section measurements of neutron-deuteron breakup at 13.0 MeV
International Nuclear Information System (INIS)
Setze, H.R.; Howell, C.R.; Tornow, W.; Braun, R.T.; Gonzalez Trotter, D.E.; Hussein, A.H.; Pedroni, R.S.; Roper, C.D.; Salinas, F.; Slaus, I.; Vlahovic, B.; Walter, R.L.; Mertens, G.; Lambert, J.M.; Witala, H.; Gloeckle, W.
2005-01-01
Cross-section measurements of seven exit-channel configurations in the neutron-deuteron breakup at 13.0 MeV are reported and compared to rigorous calculations. Our data are consistent with those of previous measurements in four of six configurations. The present data for five configurations are in good agreement with theoretical predictions. The cross-section data for the space-star and another out-of-plane configuration are larger than the theoretical predictions by more than three standard deviations. The previously observed 20% discrepancy between theory and data for the space-star configuration is confirmed in the present work. The inclusion of the Tucson-Melbourne 2π-exchange three-nucleon force changes the predicted cross section by only 2% and in the wrong direction needed to bring theory into agreement with data
Analysis of fusion neutronics calculations and appraisal of UW cross-section library
International Nuclear Information System (INIS)
Xie Jianping; Li Xingzhong; Ying Chuntong
1989-01-01
A series of calculations for different cases (especially for the values of tritium breeding ratio T, and the fuel breeding ratio F in the blanket of a hybrid reactor) were carried out by using ANISN program and UW cross-section library. The comparison with other results in China and abroad kalso was done. It was shownwn that the installation and execution of ANISN program on ELXSI machine at Tsinghua University are successful, and the UW cross-section library is reliable. It may be used for fusion neutronics calculation in the future. The paper also points out that the difference between the calculations and by the authors are due to jthe different in cross-section data used
Kilo-electron-volt neutron capture cross sections of the krypton isotopes
International Nuclear Information System (INIS)
Walter, G.; Leugers, B.; Kappeler; Bao, Z.Y.; Reffo, G.; Fabbri, F.
1986-01-01
The neutron capture cross sections of the stable krypton isotopes were determined in the energy interval from 4 to 250 keV using a C/sub 6/D/sub 6/-detector system in conjunction with the time-of-flight technique. The energy resolution of the measurement was 4% at 20 keV and 6% at 100 keV, and the experimental uncertainties were typically 6 to 10%. The measurements were complemented by statistical model calculations of all krypton isotopes in the mass range 78 < A < 86 to also obtain reliable cross sections for the unstable nuclei /sup 79,81,85/Kr. These calculations were based on local systematics for all relevant parameters, and the results were estimated to show uncertainties of 20 to 25%. Maxwellian average cross sections were calculated for kT=30 keV
Kotlarchyk, Michael; Thurston, George M
2016-12-28
In this work we study the potential for utilizing the scattering of polarized neutrons from nuclei whose spin has been modulated using nuclear magnetic resonance (NMR). From first principles, we present an in-depth development of the differential scattering cross sections that would arise in such measurements from a hypothetical target system containing nuclei with non-zero spins. In particular, we investigate the modulation of the polarized scattering cross sections following the application of radio frequency pulses that impart initial transverse rotations to selected sets of spin-1/2 nuclei. The long-term aim is to provide a foundational treatment of the scattering cross section associated with enhancing scattering signals from selected nuclei using NMR techniques, thus employing minimal chemical or isotopic alterations, so as to advance the knowledge of macromolecular or liquid structure.
Neutron-induced cross sections of actinides via the surrogate-reaction method
Directory of Open Access Journals (Sweden)
Tveten G. M.
2013-03-01
Full Text Available The surrogate-reaction method is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method for extracting capture cross sections has to be investigated. In this work we study the reactions 238U(d,p239U, 238U(3He,t238Np, 238U(3He,4He237U as surrogates for neutroninduced reactions on 238U, 237Np and 236U, respectively, for which good quality data exist. The experimental set-up enabled the measurement of fission and gamma-decay probabilities. First results are presented and discussed.
Determination of the neutron-induced fission cross section of 242Pu
International Nuclear Information System (INIS)
Koegler, Toni Joerg
2016-01-01
Neutron induced fission cross sections of actinides like the Pu-isotopes are of relevance for the development of nuclear transmutation technologies. For 242 Pu, current uncertainties are of around 21%. Sensitivity studies show that the total uncertainty has to be reduced to below 5% to allow for reliable neutron physics simulations. This challenging task was performed at the neutron time-of-flight facility of the new German National Center for High Power Radiation Sources at HZDR, Dresden. Within the TRAKULA project, thin, large and homogeneous deposits of 235 U and 242 Pu have been produced successfully. Using two consecutively placed fission chambers allowed the determination of the neutron induced fission cross section of 242 Pu relative to 235 U. The areal density of the Plutonium targets was calculated using the measured spontaneous fission rate. Experimental results of the fast neutron induced fission of 242 Pu acquired at nELBE will be presented and compared to recent experiments and evaluated data. Corrections addressing the neutron scattering are discussed by using results of different neutron transport simulations (Geant 4, MCNP 6 and FLUKA).
Filtered thermal neutron captured cross-sections measurements and decay heat calculations
International Nuclear Information System (INIS)
Son, Pham Ngoc; Tan, Vuong Huu
2014-01-01
Recently, a pure thermal neutron beam has been developed for neutron capture measurements based on the horizontal channel No.2 of the research reactor at the Nuclear Research Institute, Dalat. The original reactor neutron spectrum is transmitted through an optimal composition of Bi and Si single crystals for delivering a thermal neutron beam with Cadmium ratio (R cd ) of 420 and neutron flux (Φ th ) of 1.6x10 6 n/cm 2 .s. This thermal neutron beam has been applied for measurements of capture cross-sections for nuclide of 51 V, 55 Mn, 180 Hf and 186 W by the activation method relative to the standard reaction 197 Au(n,g) 198 Au. In addition to the activities of neutron capture cross-sections measurements, the study on nuclear decay heat calculations has been also considered to be developed at the Institute. Some results on calculation procedure and decay heat values calculated with update nuclear database for 235 U, 238 U, 239 Pu and 232 Th are introduced in this report. (author)
Neutron-capture-activation cross sections of 9496Zr and 98100Mo at thermal and 30 keV energy
International Nuclear Information System (INIS)
Wyrick, J.M.; Poenitz, W.P.
1982-01-01
Neutron-capture cross sections of 94 96 Zr and 98 100 Mo were measured relative to the standard-capture cross section of gold at thermal and 30 keV neutron energies using the activation technique. The reported values are based upon available decay-scheme information
Measurement of the fission cross-section ratio for 237Np/235U around 14 MeV neutron energies
International Nuclear Information System (INIS)
Desdin, L.; Szegedy, S.; Csikai, J.
1989-01-01
Fission cross-section ratio was determined for 237 Np/ 235 U around 14 MeV neutron energies with a back-to-back ionization chamber. Neutrons were produced by a 180 KV accelerator using T(d,n) 4 He reaction. No significant energy dependence was found in the cross section ratio
Neutron-scattering cross section of the S=1/2 Heisenberg triangular antiferromagnet
DEFF Research Database (Denmark)
Lefmann, K.; Hedegård, P.
1994-01-01
In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with lo...... no elastic, but a set of broader dispersive spin excitations around kappa almost-equal-to (1/2, 0) and around kappa almost-equal-to (1/3, 1/3) for omega/E(g) = 2.5-4. It should thus be possible to distinguish these two states in a neutron-scattering experiment.......In this paper we use a Schwinger-boson mean-field approach to calculate the neutron-scattering cross section from the S = 1/2 antiferromagnet with nearest-neighbor isotropic Heisenberg interaction on a two-dimensional triangular lattice. We investigate two solutions for T = 0: (i) a state with long......-range order resembling the Neel state and (ii) a resonating valence bond or ''spin liquid'' state with an energy gap, E(g) almost-equal-to 0.17J, for the elementary excitations (spinons). For solution (ii) the neutron cross section shows Bragg rods at kappa = K = (1/3, 1/3), whereas solution (ii) shows...
Stellar Neutron Capture Cross Sections of the Lu and Hf Isotopes
International Nuclear Information System (INIS)
Wisshak, K.; Voss, F.; Kaeppeler, F.; Kazakov, L.; Krticka, M.
2005-01-01
The neutron capture cross sections of 175,176Lu and 176,177,178,179,180Hf have been measured in the energy range from 3 to 225 keV at the Karlsruhe 3.7 MV Van de Graaff accelerator relative to the gold standard. Neutrons were produced by the 7Li(p,n)7Be reaction and capture events were detected by the Karlsruhe 4πBaF2 detector. The cross section ratios could be determined with uncertainties between 0.9 and 1.8% about a factor of five more accurate than previous data. A strong population of isomeric states was found in neutron capture of the Hf isotopes, which are only partially explained by CASINO/GEANT simulations based on the known level schemes.Maxwellian averaged neutron capture cross sections were calculated for thermal energies between kT = 8 keV and 100 keV. Severe differences up to40% were found to the data of a recent evaluation based on existing experimental results. The new data allow for a much more reliable analysis of the important branching in the s-process synthesis path at 176Lu which can be interpreted as an s-process thermometer
Energy Technology Data Exchange (ETDEWEB)
Zaman, Muhammad; Kim, Guinyun; Kim, Kwangsoo; Nadeem, Muhammad [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Naik, Haladhara [Kyungpook National University, Department of Physics and Center for High Energy Physics, Daegu (Korea, Republic of); Bhabha Atomic Research Centre, Radiochemistry Division, Mumbai (India); Lee, Manwoo [Dongnam Inst. of Radiological and Medical Sciences, Research Center, Busan (Korea, Republic of)
2017-09-15
The neutron induced cross sections of the {sup 89}Y(n, 2n){sup 88}Y, {sup 89}Y(n, 3n){sup 87}Y and {sup 89}Y(n, 4n){sup 86}Y reactions were measured in the neutron energy range of 15.2 to 37.2 MeV by using an activation and off-line γ-ray spectrometric technique. The quasi-monoenergetic neutrons used for the above reactions are based on a {sup 9}Be(p, n) reaction. Simulations of the neutron spectra from the Be target were done using the MCNPX 2.6.0 program. Theoretical calculations were performed for the {sup 89}Y(n, 2n){sup 88}Y, {sup 89}Y(n, 3n){sup 87}Y and {sup 89}Y(n, 4n){sup 86}Y reaction cross sections using nuclear model code Talys 1.8. The measured and calculated cross sections were compared with the literature data given in EXFOR and the TENDL-2015 data libraries. The present data of the {sup 89}Y(n, xn) reaction were also compared with the similar data of the {sup 89}Y(γ, xn) reaction to examine the effect of the entrance channel parameters as well as the role of projectiles and ejectiles. (orig.)
Cross section measurements of the (n,2n) reaction with 14 MeV neutrons
Energy Technology Data Exchange (ETDEWEB)
Kaji, Harumi; Shiokawa, Takanobu [Tohoku Univ., Sendai (Japan). Faculty of Science; Suehiro, Teruo; Yagi, Masuo
1975-07-01
Cross sections are measured for the reactions /sup 64/Zn(n, 2n)/sup 63/Zn, /sup 75/As(n, 2n)/sup 74/As, /sup 79/Br(n, 2n)/sup 78/Br, /sup 90/Zr(n, 2n)/sup 89/Zr, /sup 141/Pr(n, 2n)/sup 140/Pr and /sup 144/Sm(n, 2n)/sup 143/Sm by activation method in the energy range 13.5-14.8 MeV. The cross sections are determined relatively to the cross section for the /sup 63/Cu(n, 2n)/sup 62/Cu and /sup 19/F(n, 2n)/sup 18/F reactions. Before the cross section measurement, incident-neutron energies are measured by recoil proton method. The results of the cross sections are compared with data existing in the literatures and are discussed with reference to the theory of Weisskopf and Ewing.
Cross section sensitivity study for fusion blankets incorporating lead neutron multiplier
International Nuclear Information System (INIS)
Pelloni, S.; Cheng, E.T.
1983-01-01
In the recent European INTOR design, lead has been considered for incorporation in the blanket as either an explicit or implicit neutron multiplier. The blanket employs either Li 2 SiO 3 or Li 17 Pb 83 as tritium breeding material. Nucleonic analysis was performed for this blanket using the DLC37 and DLC41 cross section libraries. The reaction rates were estimated using the reaction cross sections provided with both libraries. In addition to that, they were estimated using the MACKLIB-IV response library. The calculated tritium breeding ratio was found to be 5% less and 15% more in the calculations with DLC41 and DLC41 plus MACKLIB-IV libraries, respectively, than in the calculation with the DLC37 library. The Fe, Pb, and Li cross sections given by the ENDF/B-IV and V were reviewed. A sensitivity study of these cross section uncertainties shows that the tritium breeding ratio is relatively insensitive to the above mentioned partial cross sections. The calculated tritium breeding ratio can be known within +-2%. (Auth.)
Investigation of the 232Th neutron cross-sections in resonance energy range
International Nuclear Information System (INIS)
Grigoriev, Yu.V.; Kitaev, V.Ya.; Sinitsa, V.V.; Zhuravlev, B.V.; Borzakov, S.B.; Faikov-Stanchik, H.; Ilchev, G.L.; Panteleev, Ts.Ts.; Kim, G.N.
2001-01-01
The alternative path in the development of atomic energy is the uranium-thorium cycle. In connection with this, the measurements of the 232 Th neutron capture and total cross-sections and its resonance self-shielding coefficients in resonance energy range are necessary because of their low accuracy. In this work, the results of the investigations of the thorium-232 neutron cross-sections are presented. The measurements have been carried out on the gamma-ray multisection liquid detector and neutron detector as a battery of boron counters on the 120 m flight path of the pulsed fast reactor IBR-30. As the filter samples were used the metallic disks of various thickness and diameter of 45 mm. Two plates from metallic thorium with thickness of 0.2 mm and with the square of 4.5x4.5 cm 2 were used as the radiator samples. The group neutron total and capture cross-sections within the accuracy of 2-7% in the energy range of (10 eV-10 keV) were obtained from the transmissions and the sum spectra of g-rays from the fourth multiplicity to the seventh one. The neutron capture group cross-sections of 238 U were used as the standard for obtaining of thorium ones. Analogous values were calculated on the GRUCON code with the ENDF/B-6, JENDL-3 evaluated data libraries. Within the limits of experimental errors an agreement between the experiment and calculation is observed, but in some groups the experimental values are larger than the calculated ones. (author)
Total and (n, 2n) neutron cross section measurements on 241Am
International Nuclear Information System (INIS)
Sage, C.
2009-01-01
Neutron induced reaction cross sections on 241 Am have been measured at the IRMM in Geel, Belgium, in the frame of a collaboration between the EC Joint Research Centres IRMM and ITU and French laboratories from CNRS and CEA. Raw material coming from the Atalante facility of CEA Marcoule has been transformed into suitable AmO 2 samples embedded in Al 2 O 3 and Y 2 O 3 matrices. The irradiations for the 241 Am(n, 2n) 240 Am reaction cross section measurement were carried out at the 7 MV Van de Graaff accelerator using the activation technique with quasi mono-energetic neutrons from 8 to 21 MeV produced via the D(d, n) 3 He and the T(d, n) 4 He reactions. The cross section was determined relative to the 27 Al(n, α) 24 Na standard cross section and was investigated for the first time above 15 MeV. The induced activity was measured off-line by standard γ-ray spectrometry using a high purity Ge detector. A special effort was made for the estimation of the uncertainties and the correlations between our experimental points. A different sample of the same isotope 241 Am has been measured in transmission and capture experiments in the resolved resonance region at the neutron ToF facility GELINA. The transmission measurement was performed in two campaigns, with an upgrade of the whole data acquisition system in between, followed by an investigation of its new performances. A preliminary analysis of the resonance parameters tends to confirm the recent evaluation to a higher value for the cross section at the bottom of the first resonances. A new design of C 6 D 6 detectors for capture measurements has been studied, but the data reduction and analysis of the measurement are not part of this work. (author) [fr
RSAP - A Code for Display of Neutron Cross Section Data and SAMMY Fit Results
International Nuclear Information System (INIS)
Sayer, R.O.
2001-01-01
RSAP is a computer code for display of neutron cross section data and selected SAMMY output. SAMMY is a multilevel R-matrix code for fitting neutron time-of-flight cross-section data using Bayes' method. RSAP, which runs on the Digital Unix Alpha platform, reads ORELA Data Files (ODF) created by SAMMY and uses graphics routines from the PLPLOT package. In addition, RSAP can read data and/or computed values from ASCII files with a format specified by the user. Plot output may be displayed in an X window, sent to a postscript file (rsap.ps), or sent to a color postscript file (rsap.psc). Thirteen plot types are supported, allowing the user to display cross section data, transmission data, errors, theory, Bayes fits, and residuals in various combinations. In this document the designations theory and Bayes refer to the initial and final theoretical cross sections, respectively, as evaluated by SAMMY. Special plot types include Bayes/Data, Theory--Data, and Bayes--Data. Output from two SAMMY runs may be compared by plotting the ratios Theory2/Theory1 and Bayes2/Bayes1 or by plotting the differences (Theory2-Theory1) and (Bayes2-Bayes1)
Directory of Open Access Journals (Sweden)
Meigo Shin-ichiro
2017-01-01
Full Text Available To estimate the lifetime and the radiation dose of the proton beam window used in the spallation neutron source at J-PARC, it is necessary to understand the accuracy of the production cross section of 3-GeV protons. To obtain data on aluminum, the reaction cross section of aluminum was measured at the entrance of the beam dump placed in the 3-GeV proton synchrotron. Owing to the use of well-calibrated current transformers and a well-collimated beam, the present data has good accuracy. After irradiation, the cross sections of Al(p,x7Be, Al(p,x22Na-22 and Al(p,x24Na were obtained by gamma-ray spectroscopy using a Ge detector. It was found that the evaluated data of JENDL/HE-2007 agree well with the current experimental data, whereas intra-nuclear cascade models (Bertini, INCL-4.6, and JAM with the GEM statistical decay model underestimate by about 30% in general. Moreover, gas production, such as T and He, and the cross sections were measured for carbon, which was utilized as the muon production target in J-PARC. The experiment was performed with 3-GeV proton having beam power of 0.5 MW, and the gasses emitted in the process were observed using a quadrupole mass spectrometer in the vacuum line for beam transport to the mercury target. It was found that the JENDL/HE-2007 data agree well with the present experimental data.
Energy Technology Data Exchange (ETDEWEB)
Iga, Kiminori; Ishibashi, Kenji; Shigyo, Nobuhiro [Kyushu Univ., Fukuoka (Japan)] [and others
1998-03-01
Neutron and gamma-ray production double differential cross sections were measured for iron by the use of 1.5 GeV {pi}{sup +} mesons. The measured cross sections were compared with the calculated values by HETC-KFA2. For the neutrons, the calculated results deviate from the experimental data in the neutron energy region below 30 MeV. The calculated values of gamma-ray production agree with the experimental data at gamma-ray energies from 1 to 7 MeV within a factor of three. (author)
The spin-spin effect in the total neutron cross section of polarized neutrons on polarized 165Ho
International Nuclear Information System (INIS)
Fasoli, U.; Galeazzi, G.; Pavan, P.; Toniolo, D.; Zago, G.; Zannoni, R.
1978-01-01
The spin-spin effect in the total neutron cross section of polarized neutrons on polarized 165 Ho has been measured in the energy interval 0.4 to 2.5 MeV, in perpendicular geometry. The results are consistent with zero effect. The spin-spin cross section sigmasub(ss) has been theoretically evaluated by a non-adiabatic coupled-channel calculation. From the comparison between the experimental and theoretical results a value Vsub(ss) = 9+-77 keV for the strength of the spin-spin potential has been obtained. Compound-nucleus effects do not seem to be relevant. (Auth.)
Directory of Open Access Journals (Sweden)
Simakov S.P.
2010-10-01
Full Text Available The reaction of protons on 7Li target produces the high-energy quasi- monoenergetic neutron spectrum with the tail to lower energies. Proton energies of 19.8, 25.1, 27.6, 30.1, 32.6, 35.0 and 37.4 MeV were used to obtain quasi-monoenergetic neutrons with energies of 18, 21.6, 24.8, 27.6, 30.3, 32.9 and 35.6 MeV, respectively. Nb cross-section data for neutron energies higher than 22.5 MeV do not exist in the literature. Nb is the important material for fusion applications (IFMIF as well. The variable-energy proton beam of NPI cyclotron is utilized for the production of neutron field using thin lithium target. The carbon backing serves as the beam stopper. The system permits to produce neutron flux density about 109 n/cm2/s in peak at 30 MeV neutron energy. The niobium foils of 15 mm in diameter and approx. 0.75 g weight were activated. The nuclear spectroscopy methods with HPGe detector technique were used to obtain the activities of produced isotopes. The large set of neutron energies used in the experiment allows us to make the complex study of the cross-section values. The reactions (n,2n, (n,3n, (n,4n, (n,He3, (n,α and (n,2nα are studied. The cross-sections data of the (n,4n and (n,2nα are obtained for the first time. The cross-sections of (n,2n and (n,α reactions for higher neutron energies are strongly influenced by low energy tail of neutron spectra. This effect is discussed. The results are compared with the EAF-2007 library.
International Nuclear Information System (INIS)
Alekseev, A.A.; Bergman, A.A.; Berlev, A.I.; Koptelov, E.A.; Egorov, A.S.; Samylin, B.F.; Trufanov, A.M.; Fursov, B.I.; Shorin, V.S.
2012-01-01
The neutron induced fission cross sections of Am and Cm isotopes were measured relative to 239 Pu in the neutron energy range from 1 eV to 20 keV at the INR RAS lead slowing down spectrometer LSDS-100. The fission resonance integrals were also estimated using the measured cross section data. The results have been compared with the available experimental and evaluated data. This analysis has shown the present status of the measured fission cross sections and the necessity to revise the evaluated cross sections libraries for the minor actinides. (author)
Neutron cross-sections for advanced nuclear systems: the n_TOF project at CERN
Directory of Open Access Journals (Sweden)
Barbagallo M.
2014-01-01
Full Text Available The study of neutron-induced reactions is of high relevance in a wide variety of fields, ranging from stellar nucleosynthesis and fundamental nuclear physics to applications of nuclear technology. In nuclear energy, high accuracy neutron data are needed for the development of Generation IV fast reactors and accelerator driven systems, these last aimed specifically at nuclear waste incineration, as well as for research on innovative fuel cycles. In this context, a high luminosity Neutron Time Of Flight facility, n_TOF, is operating at CERN since more than a decade, with the aim of providing new, high accuracy and high resolution neutron cross-sections. Thanks to the features of the neutron beam, a rich experimental program relevant to nuclear technology has been carried out so far. The program will be further expanded in the near future, thanks in particular to a new high-flux experimental area, now under construction.
Fast-neutron total and scattering cross sections of elemental palladium
Energy Technology Data Exchange (ETDEWEB)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-06-01
Neutron total cross sections of palladium are measured from approx. = 0.6 to 4.5 MeV with resolutions of approx. = 30 to 70 keV at intervals of less than or equal to 50 keV. Differential neutron elastic- and inelastic-scattering cross sections are measured from 1.4 to 3.85 MeV at intervals of 50 to 100 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160/sup 0/. The experimental results are compared with respective quantities given in ENDF/B-V and used to deduce an optical potential that provides a good description of the measured values.
Fast-neutron total and scattering cross sections of elemental palladium
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-06-01
Neutron total cross sections of palladium are measured from approx. = 0.6 to 4.5 MeV with resolutions of approx. = 30 to 70 keV at intervals of less than or equal to 50 keV. Differential neutron elastic- and inelastic-scattering cross sections are measured from 1.4 to 3.85 MeV at intervals of 50 to 100 keV and at 10 to 20 scattering angles distributed between approx. = 20 and 160 0 . The experimental results are compared with respective quantities given in ENDF/B-V and used to deduce an optical potential that provides a good description of the measured values
Neutron-induced cross sections of actinides via the surrogate-reaction method
Directory of Open Access Journals (Sweden)
Ducasse Q.
2013-12-01
Full Text Available The surrogate-reaction method is an indirect way of determining cross sections for reactions that proceed through a compound nucleus. This technique may enable neutron-induced cross sections to be extracted for short-lived nuclei that otherwise cannot be measured. However, the validity of the surrogate method has to be investigated. In particular, the absence of a compound nucleus formation and the Jπ dependence of the decay probabilities may question the method. In this work we study the reactions 238U(d,p239U, 238U(3He,t238Np, 238U(3He,4He237U as surrogates for neutron-induced reactions on 238U, 237Np and 236U, respectively, for which good quality data exist. The experimental set-up enabled the measurement of fission and gamma-decay probabilities. The first results are hereby presented.
Fast-neutron total and scattering cross sections of 103Rh
International Nuclear Information System (INIS)
Smith, A.B.; Guenther, P.T.; Whalen, J.F.
1982-07-01
Fast-neutron total cross sections of 103 Rh are measured with 30 to 50 keV resolutions from 0.7 to 4.5 MeV. Differential elastic- and inelastic-scattering cross sections are measured from 1.45 to 3.85 MeV. Scattered-neutron groups corresponding to excited levels at 334 +- 13, 536 +- 7, 648 +- 25, 796 +- 20, 864 +- 22, 1120 +- 22, 1279 +- 50, 1481 +- 27, 1683 +- 39, 1840 +- 79, 1991 +- 71 and 2050 (tentative) keV are observed. An optical-statistical model is derived from the elastic-scattering results. The experimental values are compared with comparable quantities given in the ENDF/B-V evaluation
Coherent production on nuclei and measurements of total cross sections for unstable particles
International Nuclear Information System (INIS)
Czyz, W.; Zielinski, M.
1980-01-01
The Koelbig-Margolis Formula is fitted to some explicity nonperturbative models of diffractive production. It is shown that, in spite of the fact that the standard procedure of fitting the integrated cross sections may give acceptable fits, thus obtained ''cross sections of unstable particles'', grossly disagree with the ''true'' cross sections known exactly from the models. (author)
International Nuclear Information System (INIS)
Tang Hongqing; Qi Bujia; Zhou Zuying; Sa Jun; Ke Zunjian; Sui Qingchang; Xia Haihong; Shen Guanren
1992-01-01
The status and technique of double differential cross section measurement of secondary neutrons in the incident neutron energy range 9 to 13 MeV is reviewed with emphasis on the work done at CIAE. There are scarce measurements of secondary neutron double differential cross sections in this energy region up to now. A main difficulty for this is lack of an applicable monoenergetic neutron source. When monoenergetic neutron energy reaches 8 Me/v, the break-up neutrons from the d + D or p + T reaction starts to become significant. It is difficult to get a pure secondary neutron spectrum induced only by monoenergetic neutrons. To solve this problem an abnormal fast neutron TOF facility was designed and tested. Double differential neutron emission cross sections of 238 U and 209 Bi at 10 MeV were obtained by combining the data measured by both normal and abnormal TOF spectrometers and a good agreement between measurement and calculation was achieved
International Nuclear Information System (INIS)
Bozoian, M.; Arthur, E.D.; Perry, R.T.; Wilson, W.B.; Young, P.G.
1988-01-01
Activation problems associated with particle accelerators are commonly dominated by reactions of secondary neutrons produced in reactions of beam particles with accelerator or beam stop materials. Measured values of neutron-activation cross sections above a few MeV are sparse. Calculations with the GNASH code have been made for neutrons incident on all stable nuclides of a range of elements common to accelerator materials. These elements include B, C, N, O, Ne, Mg, Al, Si, P, S, Ar, K, Ca, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Mo, Nd, and Sm. Calculations were made for a grid of incident neutron energies extending to 100 MeV. Cross sections leading to the direct production of as many as 87 activation products for each of 84 target nuclide were tabulated on this grid of neutron energies, each beginning with the threshold for the product nuclide's formation. Multigrouped values of these cross sections have been calculated and are being integrated into the cross-section library of the REAC-2 neutron activation code. Illustrative cross sections are presented. 20 refs., 6 figs., 1 tab
Cross-sectional study of health effects of cryolite production
DEFF Research Database (Denmark)
Friis, Henrik; Clausen, J; Gyntelberg, F
1989-01-01
A cross-sectional health study of 101 cryolite workers was performed, using spirometry and a questionnaire. Multiple regression analysis revealed a significant correlation between the index of smoking and a decrease in FEV1 (per cent). There was no significant correlation between work-related exp......A cross-sectional health study of 101 cryolite workers was performed, using spirometry and a questionnaire. Multiple regression analysis revealed a significant correlation between the index of smoking and a decrease in FEV1 (per cent). There was no significant correlation between work...
New Maxwellian averaged neutron capture cross sections for 35,37Cl
International Nuclear Information System (INIS)
Guber, K.H.; Sayer, R.O.; Valentine, T.E.; Leal, L.C.; Spencer, R.R.; Harvey, J.A.; Koehler, P.E.; Rauscher, T.
2002-01-01
The Oak Ridge Electron Linear Accelerator (ORELA) was used to measure neutron total and capture cross sections of natural chlorine in the energy range from 100 eV to 600 keV. We performed an R-matrix analysis of our new capture and transmission data up to 500 keV. From these resonance parameters new (n,γ) astrophysical reaction rates were determined over the entire energy range needed by the latest stellar models of the s process
The Radiative Capture Cross-Section of U 238 for Fast Neutrons
International Nuclear Information System (INIS)
Broda, E.
1945-01-01
This report was written by E. Broda and D.H. Wilkinson at the Cavendish Laboratory (Cambridge) in January 1945 and is about the radiative capture cross-section of U238 for fast neutrons. The Chemical procedure and beta counting, the notes on the activation of the samples, the results and an appendix as well as a short introduction can be found in this report. (nowak)
Above-threshold structure in {sup 244}Cm neutron-induced fission cross section
Energy Technology Data Exchange (ETDEWEB)
Maslov, V.M. [Radiation Physics and Chemistry Problems Inst., Minsk-Sosny (Belarus)
1997-03-01
The quasi-resonance structure appearing above the fission threshold in neutron-induced fission cross section of {sup 244}Cm(n,f) is interpreted. It is shown to be due to excitation of few-quasiparticle states in fissioning {sup 245}Cm and residual {sup 244}Cm nuclides. The estimate of quasiparticle excitation thresholds in fissioning nuclide {sup 245}Cm is consistent with pairing gap and fission barrier parameters. (author)
A unified Monte Carlo approach to fast neutron cross section data evaluation.
Energy Technology Data Exchange (ETDEWEB)
Smith, D.; Nuclear Engineering Division
2008-03-03
A unified Monte Carlo (UMC) approach to fast neutron cross section data evaluation that incorporates both model-calculated and experimental information is described. The method is based on applications of Bayes Theorem and the Principle of Maximum Entropy as well as on fundamental definitions from probability theory. This report describes the formalism, discusses various practical considerations, and examines a few numerical examples in some detail.
Thermal neutron capture cross section for Fe-56(n,gamma)
Czech Academy of Sciences Publication Activity Database
Firestone, R. B.; Belgya, T.; Krtička, M.; Bečvář, F.; Szentmiklosi, L.; Tomandl, Ivo
2017-01-01
Roč. 95, č. 1 (2017), č. článku 014328. ISSN 2469-9985 R&D Projects: GA ČR GA13-07117S; GA MŠk LM2015056 Institutional support: RVO:61389005 Keywords : neutron cross section * gamma gamma-coincidence data Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders OBOR OECD: Nuclear physics Impact factor: 3.820, year: 2016
The Radiative Capture Cross-Section of U 238 for Fast Neutrons
Energy Technology Data Exchange (ETDEWEB)
Broda, E.
1945-07-01
This report was written by E. Broda and D.H. Wilkinson at the Cavendish Laboratory (Cambridge) in January 1945 and is about the radiative capture cross-section of U238 for fast neutrons. The Chemical procedure and beta counting, the notes on the activation of the samples, the results and an appendix as well as a short introduction can be found in this report. (nowak)
Review of magnetic fusion energy neutron cross section needs: neutronics viewpoint
International Nuclear Information System (INIS)
Dudziak, D.J.; Muir, D.W.
1977-01-01
In the overall context of fusion nucleonic analysis, most cross section deficiencies lie in the energy range 14 MeV and below. This review deals not only with new data requirements generated by current interest in d-Li sources but also with the needs of conventional nucleonic studies (i.e., 14-MeV source calculations). The many compilations of requirements are referenced, and the current assessment of high-priority needs is succinctly summarized. Then typical methodology and results (sensitivity and uncertainty analysis) are given for quantitative data assessments of the Tokamak Fusion Test Reactor and a fusion Experimental Power Reactor. Finally, a summary is presented of some probings into data above 14 MeV, which have potential applications for d-Li irradiation facilities, d-Be medical therapy sources, and electronuclear fuel production facilities. 2 figures, 9 tables
Sensitivity Analysis of Nuclide Importance to One-Group Neutron Cross Sections
International Nuclear Information System (INIS)
Sekimoto, Hiroshi; Nemoto, Atsushi; Yoshimura, Yoshikane
2001-01-01
The importance of nuclides is useful when investigating nuclide characteristics in a given neutron spectrum. However, it is derived using one-group microscopic cross sections, which may contain large errors or uncertainties. The sensitivity coefficient shows the effect of these errors or uncertainties on the importance.The equations for calculating sensitivity coefficients of importance to one-group nuclear constants are derived using the perturbation method. Numerical values are also evaluated for some important cases for fast and thermal reactor systems.Many characteristics of the sensitivity coefficients are derived from the derived equations and numerical results. The matrix of sensitivity coefficients seems diagonally dominant. However, it is not always satisfied in a detailed structure. The detailed structure of the matrix and the characteristics of coefficients are given.By using the obtained sensitivity coefficients, some demonstration calculations have been performed. The effects of error and uncertainty of nuclear data and of the change of one-group cross-section input caused by fuel design changes through the neutron spectrum are investigated. These calculations show that the sensitivity coefficient is useful when evaluating error or uncertainty of nuclide importance caused by the cross-section data error or uncertainty and when checking effectiveness of fuel cell or core design change for improving neutron economy
Status report and measurement of total cross-sections at the Pohang Neutron Facility
International Nuclear Information System (INIS)
Kim, G.N.; Meaze, A.K.M.M.H.; Ahmed, H.
2004-01-01
We report the status of the Pohang Neutron Facility which consists of an electron linear accelerator, a water-cooled Ta target, and an 11-m time-of-flight path. It has been equipped with a four-position sample changer controlled remotely by a CAMAC data acquisition system, which allows simultaneous accumulation of the neutron time of flight spectra from 4 different detectors. It is possible to measure the neutron total cross-sections in the neutron energy range from 0.1 eV to 100 eV by using the neutron time of flight method. A 6 LiZnS(Ag) glass scintillator was used as a neutron detector. The neutron flight path from the water-cooled Ta target to the neutron detector was 10.81±0.02 m. The background level was determined by using notch-filters of Co, In, Ta, and Cd sheets. In order to reduce the gamma rays from Bremsstrahlung and those from neutron capture, we employed a neutron-gamma separation system based on their different pulse shapes. The present measurements are in general agreement with the evaluated data in ENDF/B-VI. The resonance parameters were extracted from the transmission data from the SAMMY fitting and compared with the previous ones. (author)
International Nuclear Information System (INIS)
Smith, L.A.; Gallmeier, F.X.; Gehin, J.C.
1995-05-01
The FOEHN critical experiment was analyzed to validate the use of multigroup cross sections and Oak Ridge National Laboratory neutronics computer codes in the design of the Advanced Neutron Source. The ANSL-V 99-group master cross section library was used for all the calculations. Three different critical configurations were evaluated using the multigroup KENO Monte Carlo transport code, the multigroup DORT discrete ordinates transport code, and the multigroup diffusion theory code VENTURE. The simple configuration consists of only the fuel and control elements with the heavy water reflector. The intermediate configuration includes boron endplates at the upper and lower edges of the fuel element. The complex configuration includes both the boron endplates and components in the reflector. Cross sections were processed using modules from the AMPX system. Both 99-group and 20-group cross sections were created and used in two-dimensional models of the FOEHN experiment. KENO calculations were performed using both 99-group and 20-group cross sections. The DORT and VENTURE calculations were performed using 20-group cross sections. Because the simple and intermediate configurations are azimuthally symmetric, these configurations can be explicitly modeled in R-Z geometry. Since the reflector components cannot be modeled explicitly using the current versions of these codes, three reflector component homogenization schemes were developed and evaluated for the complex configuration. Power density distributions were calculated with KENO using 99-group cross sections and with DORT and VENTURE using 20-group cross sections. The average differences between the measured values and the values calculated with the different computer codes range from 2.45 to 5.74%. The maximum differences between the measured and calculated thermal flux values for the simple and intermediate configurations are ∼ 13%, while the average differences are < 8%
International Nuclear Information System (INIS)
Peelle, R.W.; de Sassure, G.
1977-01-01
Refined knowledge of the thermal neutron cross sections of the fissile nuclides and of the (n,α) reaction standards, together with the reasonably well known energy dependence of the latter, have permitted resonance-region and low-keV fissile nuclide cross sections to be based on these standards together with count-rate ratios observed as a function of energy using a pulsed ''white'' source. As one evaluates cross sections for energies above 20 keV, optimum results require combination of cross section shape measurements with all available absolute measurements. The assumptions of the ''thermal normalization method'' are reviewed, and an opinion is given of the status of some of the standards required for its use. The complications which may limit the accuracy of results using the method are listed and examples are given. For the 235 U(n,f) cross section, the option is discussed of defining resonance-region fission integrals as standards. The area of the approximately 9 eV resonances in this nuclide may be known to one percent accuracy, but at present the fission integral from 0.1 to 1.0 keV is known to no better than about two percent. This uncertainty is based on the scatter among independent results, and has not been reduced by the most recent measurements. This uncertainty now limits the accuracy attainable for the 235 U(n,f) cross section below about 50 keV. Suggestions are given to indicate how future detailed work might overcome past sources of error
Measurement, calculation and evaluation of photon production cross-sections
International Nuclear Information System (INIS)
Kocherov, N.P.
1990-11-01
The meeting proceedings were divided into three sessions devoted to the following topics: Experimental measurement and techniques (3 papers), calculation of photon cross-sections (9 papers), and evaluation (2 papers). A separate abstract was prepared for each of these papers. Refs, figs and tabs
Neutron cross-section libraries in the AMPX master interface format for thermal and fast reactors
International Nuclear Information System (INIS)
Bjerke, M.A.; Webster, C.C.
1981-12-01
Neutron cross-section libraries in the AMPX master interface format have been created for three reactor types. Included are an 84-group library for use with light-water reactors, a 27-group library for use with heavy-water CANDU reactors and a 126-group library for use with liquid metal fast breeder reactors. In general, ENDF/B data were used in the creation of these libraries, and the nuclides included in each library should be sufficient for most neutronic analyses of reactors of that type. Each library has been used successfully in fuel depletion calculations
Cross section measurement for (n,n{alpha}) reactions by 14 MeV neutrons
Energy Technology Data Exchange (ETDEWEB)
Kasugai, Y.; Ikeda, Y.; Uno, Y. [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment; Yamamoto, H.; Kawade, K.
1997-03-01
Nine (n,n{alpha}) cross sections for (n,n{alpha}) reactions induced by 13.5-14.9 MeV neutrons were measured for {sup 51}V, {sup 65}Cu, {sup 71}Ga, {sup 76}Ge, {sup 87}Rb, {sup 91}Zr, {sup 93}Nb, {sup 96}Zr and {sup 109}Ag isotopes by using Fusion Neutronics Source (FNS) at JAERI. The reactions for 91Zr and 96Zr were measured for the first time. The evaluated data of JENDL-3 and ENDF/B-VI were compared with the present data. Some of the evaluated values are much different from our data by a factor more than ten. (author)
FENDL/A-2.0. Neutron activation cross section data library for fusion applications
International Nuclear Information System (INIS)
Pashchenko, A.B.; Wienke, H.; Kopecky, J.; Sublet, J.C. Sublet; Forrest, R.A.
1997-01-01
This document describes the contents of a comprehensive neutron cross section data library for 13,006 neutron activation reactions with 739 target nuclides from H (A=1,Z=1) to Cm (A=248,Z=96), in the incident energy range up to 20 MeV. FENDL/A-2 is a sublibrary of FENDL-2, the second revision of the evaluated nuclear data library for fusion applications. It is supplemented by a decay data library FENDL/D-2 in ENDF-6 format for 1867 nuclides. The data are available from the IAEA Nuclear Data Section online via INTERNET by FTP command, or on magnetic tape upon request. (author)
Absorption and activation techniques in measurements of fast-neutron capture cross sections
International Nuclear Information System (INIS)
Bergqvist, I.
1982-01-01
The absorption and activation methods have been applied for a long time to systematic studies of fast neutron capture cross sections. Both methods are simple in principle but difficult in practice. The simplicity should ensure a wider use of the methods in particular for problems which may be complicated to approach with other methods. The difficulties encountered in absorption measurements are related to multiple scattering and resonance shielding effects. In activation experiments the influence of secondary low-energy neutrons causes the main problems
Aborption and activation techniques in measurements of fast-neutron capture cross sections
International Nuclear Information System (INIS)
Bergqvist, I.
1982-01-01
The absorption and activation methods have been applied for a long time to systematic studies of fast neutron capture cross sections. Both methods are simple in principle but difficult in practice. The simplicity should ensure a wider use of the methods in particular for problems which may be complicated to approach with other methods The difficulties encountered in absorption measurements are related to multiple scattering and resonance shielding effects. In activation experiments the influence of secondary low-energy neutrons c causes the main problems. (Author)
The Cross-Section for the Radiative Capture of Thermal Neutrons by Uranium
Energy Technology Data Exchange (ETDEWEB)
Broda, E.
1942-07-01
This report is based on an experiment performed at the Cavendish Laboratory (Cambridge) by E. Broda, J. Guéron and L. Kowarski in July 1942 where the intensity of the beta-activity induced in uranium by thermal neutrons has been compared with that induced in manganese or iodine. Care was taken to avoid losses due to a Szilard-Chalmers effect. The capture cross section of uranium for thermal neutrons is found to amount to (2.78 ±0.1)*10{sup -24} cm{sup 2}, assuming the value 581*10{sup -24} cm{sup 2} for σ{sub B}. (nowak)
Measurement of 14 MeV neutron cross section of {sup 129}I with foil activation method
Energy Technology Data Exchange (ETDEWEB)
Murata, Isao; Nakano, Daisuke; Takahashi, Akito [Osaka Univ., Suita (Japan). Faculty of Engineering
1997-03-01
The {sup 129}I, which is one of the most famous fission products (FPs), is of very important concern from the standpoint of waste transmutation due to its extremely long half life. The accurate reaction cross section data of {sup 129}I induced by 14 MeV neutrons are indispensable when evaluating the performance to transmute it in a fusion reactor. However, there was no available experimental data reported until now. We measured 14 MeV neutron induced reaction cross sections of {sup 129}I to give the reference cross section data for evaluation of transmutation performance and nuclear data, using OKTAVIAN facility of Osaka university, Japan. Since the available amount of {sup 129}I as a sample is quite small, probably less than 1 mg, the foil activation method was adopted in the measurement. The sample was a sealed source of {sup 129}I and the {gamma}-rays from the irradiated sample were measured with a Hp-Ge detector. Several {gamma}-rays peaks which could be expected to be caused by two nuclear reactions of {sup 129}I(n,2n) and {sup 129}I(n,{gamma}) were observed. We confirmed that these peaks corresponded to those of {sup 128}I and {sup 130}I through ascertaining each energy and half life. From the measurement, the cross section of {sup 129}I(n,2n) and the effective production cross section of {sup 130}I produced by the {sup 129}I(n,{gamma}){sup 130}I reaction including the contribution of {sup 129}I(n,{gamma}){sup 130m}I reaction, that were estimated to be 1.1{+-}0.1 b and 0.032{+-}0.003 b, respectively at 14.8 MeV, were obtained with an acceptable accuracy of about 10 %, though the errors caused by the uncertainty of {gamma} decay scheme data still existed. The measured cross sections were compared with the evaluated nuclear data of JENDL-3.2 and ENDF/B-VI. For the {sup 129}I(n,2n) reaction, the evaluations overestimate the cross section by 30-40 %, while for the {sup 129}I(n,{gamma}) reaction, the evaluations underestimate by at least one order of magnitude
Neutron cross sections of cryogenic materials: a synthetic kernel for molecular solids
International Nuclear Information System (INIS)
Granada, J.R.; Gillette, V.H.; Petriw, S.; Cantargi, F.; Pepe, M.E.; Sbaffoni, M.M.
2004-01-01
A new synthetic scattering function aimed at the description of the interaction of thermal neutrons with molecular solids has been developed. At low incident neutron energies, both lattice modes and molecular rotations are specifically accounted for, through an expansion of the scattering law in few phonon terms. Simple representations of the molecular dynamical modes are used, in order to produce a fairly accurate description of neutron scattering kernels and cross sections with a minimum set of input data. As the neutron energies become much larger than that corresponding to the characteristic Debye temperature and to the rotational energies of the molecular solid, the 'phonon formulation' transforms into the traditional description for molecular gases. (orig.)
International Nuclear Information System (INIS)
Erradi, L.; Karouani, K.
1994-01-01
Many multigroup neutron cross section libraries have been processed from basic evaluated nuclear data for use in neutron dosimetry, reactor shielding calculation and in the development of fusion reactors. Most of these libraries have been tested only for fission spectra and were not validated for fusion spectra. Fifteen of these libraries such as DOSCROS84, IRDF85 and ENDFB5 have been used along with the neutron spectra unfolding code SAND II to evaluate about fifteen threshold detector saturated activities. The comparison between these computed activities and the measured ones of a set of foils placed in different places along the axis of a paraffin cylinder and irradiated by 14 MeV neutrons generated by a D-T source, hence giving rise to complex spectra, leads to different types of discrepancies. The analysis of these discrepancies allows to select from these libraries the ones that can be recommended. 1 fig., 4 refs. (author)
Neutron cross-sections of deuterium in the energy range 0.0001eV-15MeV
International Nuclear Information System (INIS)
Bazazyants, N.O.; Zabrodskaya, A.S.; Larina, A.F.; Nikolaev, M.N.
1978-08-01
The paper describes the evaluation of deuterium neutron cross-sections, the spectra of neutrons from the reaction D(n,2n)P and the angular distributions of neutrons from this reaction and of neutrons elastically scattered on deuterium. The evaluation results are presented in the SOCRATOR format. The 26-group system of constants for deuterium is also presented. (author)