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Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Takada, Hiroshi; Ikeda, Yujiro
Nuclear Instruments and Methods in Physics Research A, 1000, p.165252_1 - 165252_8, 2021/06
Times Cited Count：2 Percentile：33.7(Instruments & Instrumentation)This study explores high-energy neutron components of the extracted neutron beam at J-PARC pulsed neutron source using the foil activation method with threshold reactions. Foils of aluminum, gold, bismuth, niobium, and thulium were used to cover the neutron energy range from 0.3 MeV to 79.4 MeV. The experiment was performed using neutron beams of BL10 (NOBORU). The foils were irradiated by a neutron beam at 13.4 m from the moderator. To characterize high-energy neutron fields for irradiation applications, reaction rates in three different configurations with and without B
C slit and Pb filter were examined. To compare the experiments with calculations given for the user, reaction rates for corresponding reactions were calculated by the PHITS code with the JENDL-3.2 and the JENDL dosimetry file. Although there was a systematic tendency in C/E (Calculation/Experiment) ratios for different threshold energies, which C/E ratio decreased as threshold energy increased up to 100 MeV, and all C/E ratios were in the range of 1.0
0.2. This indicated that high-energy neutron calculations were adequate for the analysis of experimental data for NOBORU users.
Ishitsuka, Etsuo; Kenzhina, I. E.*; Okumura, Keisuke; Takemoto, Noriyuki; Chikhray, Y.*
JAEA-Technology 2016-022, 35 Pages, 2016/10
JAEA-Technology-2016-022.pdf:3.73MB
As a part of study on the mechanism of tritium release to the primary coolant in research and testing reactors, the calculation methods by PHITS code is studied to evaluate the recoil tritium release rate from beryllium core components. Calculations using neutron and triton sources were compared, and it is clear that the tritium release rates in both cases show similar values. However, the calculation speed for the triton source cases is two orders faster than that for the neutron source case. It is also clear that the calculation up to history number per unit volume of 2
10
(cm
) is necessary to determine the recoil tritium release rate of two effective digits precision. Furthermore, the relationship between the beryllium shape and recoil tritium release rate using the triton sources was studied. Recoil tritium release rate showed linear relation to the surface area per volume of beryllium, and the recoil tritium release rate showed about half of the conventional equation value.
Tamura, Itaru; Aizawa, Kazuya; Harada, Masahide; Shibata, Kaoru; Maekawa, Fujio; Soyama, Kazuhiko; Arai, Masatoshi
JAERI-Research 2003-008, 34 Pages, 2003/03
JAERI-Research-2003-008.pdf:1.62MB
Moderators components of the McStas code have been created for the design of JSNS instruments. Three cryogenic moderators are adopted in JSNS, One is coupled H
moderators for high intensity experiments and other two are decoupled H with poisoned or unpoisoned for high resolution moderators. Since the characteristics of neutron beams generated from moderators make influence on the performance of pulse neutron spectrometers, it is important to perform the Monte Carlo simulation with neutron source component written recisely. The neutron spectrum and time structure were calculated using NMTC/JAERI97 and MCNP4a codes. The simulation parameters, which describe the pulse shape over entire spectrum as a function of time, are optimized. In this paper, the creation of neutron source components for port No.16 viewed to coupled H moderator and for port No.11 viewed to decoupled H moderator of JSNS are reported.
