共查询到14条相似文献,搜索用时 46 毫秒
1.
ZHANGGuo-Hui LUHan-Lin 《核技术(英文版)》2001,12(3):161-164
The cross sections of the ^75As(n,γ)^76As reaction were measured in the neutron energy range from 0.50 to 1.50 MeV by using the activation technique.Neutrons were produced via the T(p,n)^3He reaction and the cross sections of the ^197Au(n,γ)^198Au reaction were used to determine the absolute neutron flux.Present results are compared with existing measurements and evaluations. 相似文献
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By using a new reaction model for light nuclei, the double-differential cross section of total outgoing neutron with LUNF code for n+^16O reactions at En=14.1 MeV and 18 MeV have been calculated and analyzed. The opened reaction channels, which have contribution to emit the neutrons, are listed in detail. To improve the fitting results the direct inelastic scattering mechanism is involved. The calculated results agree fairly well with the experimental data at En= 14.1 MeV and the deviation from calculated results and 相似文献
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《中国核科技报告》1997,(Z2)
Introduction Both ~(159)Tb and ~(169)Tm are rare-earth elements. Their activation cross sections are a good indicator for nuclear science and technology applications. Precise values of the neutron capture cross section of terbium and thulium also are of practical importance in relation to reactor design since they are the fission product poisons. 相似文献
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The cross sections for the 175Lu(n, α)172Tm, 176Lu(n, α)173Tm and 175Lu(n, p)175m+gYb reactions have been measured in the neutron energy range of 13.5–14.8 MeV using the activation technique. The first data for 175Lu(n, α)172Tm reaction cross sections are presented. In our experiment, the fast neutrons were produced via the 3H(d, n)4He reaction on K-400 Neutron Generator at Chinese Academy of Engineering Physics (CAEP). Induced gamma activities were measured by a high-resolution (1.69 keV at 1332 keV for 60Co) gamma-ray spectrometer with high-purity germanium (HPGe) detector. Measurements were corrected for gamma-ray attenuations, random coincidence (pile-up), dead time and fluctuation of neutron flux. The neutron fluences were determined by the cross section of 93Nb(n, 2n)92mNb or 27Al(n, α)24Na reactions. The neutron energy in the measurement was by the cross section ratios of 90Zr(n, 2n)89m+gZr and 93Nb(n, 2n)92mNb reactions. The results were discussed and compared with experimental data found in the literature and with results of published empirical formulae. 相似文献
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1 INTRODUCTIONThe cross sections of the "As(n,7)"As reaction are boortant in evaluating theradiation damage of the material. EXPerimeats[1-6] and evaluations have been performedto deterAnne the "As(n, 7)"As reaction cross section, but there are large discrepanciesamong them especially in the MeV neutron energy region. Therefore, new eXPerAnent isneeded.2 EXPERIMENT DETAILSThe measuremenis were perfOrmed at the 4.5 MV Van de Grand accelerator of theInstitute Of Heavy Ion Phy… 相似文献
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Kazushi Terada Taro Nakao Shoji Nakamura Kazuhito Mizuyama Nobuyuki Iwamoto 《Journal of Nuclear Science and Technology》2018,55(10):1198-1211
Neutron total and capture cross sections of 241Am have been measured with a new data acquisition system and a new neutron transmission measurement system installed in Accurate Neutron Nucleus Reaction measurement Instrument at Materials and Life Science Experimental Facility of Japan Proton Accelerator Research Complex. The neutron total cross sections of 241Am were determined by using a neutron time-of-flight (TOF) method in the neutron energy region from 4 meV to 2 eV. The thermal total cross section of 241Am was derived with an uncertainty of 2.9%. A pulse-height weighting technique was applied to determine neutron capture yields of 241Am. The neutron capture cross sections were determined by the TOF method in the neutron energy region from the thermal to 100 eV, and the thermal capture cross section was obtained with an uncertainty of 4.1%. The evaluation data of JENDL-4.0 and JEFF-3.2 were compared with the present results. 相似文献
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Kazushi Terada Taihei Matsuhashi Masayuki Igashira Tatsuya Katabuchi 《Journal of Nuclear Science and Technology》2013,50(5):671-680
The neutron capture cross sections and capture gamma-ray spectra of 105Pd were measured in the region from 15 to 100 keV and at 585 keV. A neutron time-of-flight method was utilised with an anti-Compton NaI(Tl) spectrometer and a 1.5-ns pulsed neutron source by the 7Li(p,n)7Be reaction. The capture yields were obtained by applying a pulse-height weighting technique to the observed net capture gamma-ray pulse-height spectra. The capture cross sections of 105Pd were derived with errors less than 5%, using the standard capture cross sections of 197Au. The evaluated capture cross sections of JENDL-4.0 and ENDF/B-VII.1 were compared with the present results. The evaluations of JENDL-4.0 and ENDF/B-VII.1 were larger than the present results by 3%–15% in the region from 15 to 100 keV and at 585 keV. The capture gamma-ray spectra of 105Pd were also derived by unfolding the observed net capture gamma-ray pulse-height spectra. The multiplicities of capture gamma rays of 105Pd were obtained from the capture gamma-ray spectra. 相似文献
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Measurements of the neutron capture cross sections of 107Pd were carried out at the Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). Gamma-rays were detected with an NaI(Tl) spectrometer of the Accurate Neutron–Nucleus Reaction Measurement Instrument (ANNRI). The neutron capture cross sections were determined by the time-of-flight method in the neutron energy region from the thermal to keV energies. 相似文献
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The accuracy of fast reactor core calculation is usually determined by the accuracy of self-shielded few-group cross sections. To further improve the accuracy of cross section generation, a hybrid method is proposed. In the hybrid method, the Monte-Carlo method is used to deal with the resonance effect in both the resolved and unresolved resonance range. The self-shielded ultrafine-group total, fission and elastic scattering cross sections are tallied by the Monte-Carlo method. The scattering transfer matrices are then generated in a synthesis way by using the tallied elastic scattering cross sections and a problem-independent elastic scattering function. The angular flux moments for the group condensation are calculated in an explicit deterministic way. Several tests are done to verify the hybrid method. The results show that the hybrid method avoids the disadvantages of both the traditional deterministic method and the pure Monte-Carlo method. It is a more accurate method to generate the few-group cross sections for fast reactor cores. 相似文献
13.
T. Cai 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(21):3373-3376
The cross sections for the elastic scattering of protons from tritium at 151° and from helium at 155° angles in the laboratory frame, over the energy range of 1.2-3.4 MeV, have been measured in the present work, as a supplement to previous cross section measurements determined at different scattering angles recently. The currently measured cross section data are compared to data available in literature. The cross section enhancement was also investigated for both reactions. It was found that over the whole measured energy range, the elastic cross section for protons on tritium increases linearly with energy and is about 1000 times greater than the Rutherford cross section at 3.4 MeV. On the other hand, in the case of the elastic scattering of protons from helium, the cross section below 2.3 MeV increases almost linearly, and reaches a maximum of about 300 mb/str at the energy of 2.4 MeV for the scattering angle of 165°, and then, after this energy, it keeps oscillating around the maximum. 相似文献
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W.M. Ariyasinghe G. Vilela 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2010,268(13):2217-2220
The total electron scattering cross sections (TCS) of C2H2 and C3H4 have been obtained for 200-4500 eV electrons by measuring the attenuation of the electron beam through a gas cell. An empirical expression is deduced to express the TCS of normal hydrocarbons as a function of the number of atomic constituencies in the hydrocarbon and the electron energy. 相似文献