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Fukushima, Masahiro; Okajima, Shigeaki; Ando, Masaki; Yamane, Tsuyoshi; Kataoka, Masaharu*
JAERI-Research 2005-008, 57 Pages, 2005/03
JAERI-Research-2005-008.pdf:3.49MB
no abstracts in English
Sakurai, Takeshi; *; *; *
Journal of the Physical Society of Japan, 36(8), p.661 - 670, 1999/08
no abstracts in English
U capture to 
Pu fission rate ratios and U capture to 
U fission rate ratios at fast critical assemblySakurai, Takeshi;
JAERI-Research 95-054, 36 Pages, 1995/08
JAERI-Research-95-054.pdf:1.41MB
no abstracts in English
Sakurai, Takeshi; ; Obu, Makoto; ; Kobayashi, Keiji*; Unesaki, Hironobu*
JAERI-M 93-153, 50 Pages, 1993/08
no abstracts in English
Nihon Genshiryoku Gakkai-Shi, 13(2), p.73 - 75, 1971/00
no abstracts in English
Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Takada, Hiroshi; Ikeda, Yujiro
no journal, ,
no abstracts in English
Harada, Masahide; Teshigawara, Makoto; Oi, Motoki; Oikawa, Kenichi; Ikeda, Yujiro
no journal, ,
In a spallation neutron source at Materials and Life Science Facility in J-PARC, 3GeV 1MW proton beam hits a mercury target and produced neutron beam provide to neutron instruments. Not only thermal and cold neutrons, but also high energy neutrons provide to the neutron instruments. The high energy neutrons about 1 MeV are available for a high energy neutron irradiation experiment. Because the high energy neutrons to provide the neutron instruments have been estimated by a simulation code, a validation of the high energy neutrons is necessary. In addition, neutron intensity and distribution at a sample position should be brought out as an irradiation field. Therefore, in NOBORU (BL10), high neutron intensity and distribution were measured with the foil activation method of Au, Al, Bi, In and Nb using threshold reactions in case with and without a thermal neutron filter. And the neutron distribution of the high energy neutrons was measured with an Al foil. The validation with the PHITS code indicates good agreement.
Harada, Masahide; Oikawa, Kenichi; Tsuchikawa, Yusuke; Yamaguchi, Yuji; Haga, Katsuhiro
no journal, ,
In the spallation neutron source at Materials and Life Science Experimental Facility in J-PARC, a 3-GeV and 1-MW proton beam induces into a mercury target and the neutrons beam is provide to neutron instruments. The target vessels are regularly replaced due to pitting damage. The proton beam power is gradually increased to 800 kW as of June 2022, and the optimum proton beam profile is used depending on the beam power. Based on these observations, fixed-point measurements have been periodically carried out to observe the intensity of the neutrons supplied from the spallation neutron source under the same measurement conditions at NOBORU. In the fixed-point measurements, the activation method with gold foils (15x15x0.1mm
) was used to observe the absolute intensity of thermal neutrons with and without cadmium foil. The irradiation time was set to about 10 to 30 minutes in accordance with the proton beam intensity. The gamma-ray from irradiated foil was measured with a germanium detector, and the amount of activation was identified. As a result of the measurement, the thermal neutron intensity was slightly dependent on the proton beam intensity.
Harada, Masahide; Yamaguchi, Yuji; Kawamura, Seiko; Kofu, Maiko; Nirei, Masami; Haga, Katsuhiro; Oku, Takayuki; Matsuura, Masato*; Kusaka, Katsuhiro*; Nakayama, Haruki*
no journal, ,
In the Materials and Life science experimental Facility (MLF) at J-PARC, 3 GeV proton beam is injected into a mercury target to provide neutrons produced by spallation reactions to neutron instruments, and as of June 2023, MLF is operating at 800 kW proton beam output. The intensity of neutrons provided to the neutron instruments is an important factor to characterize the performance of the neutron instruments. So far, neutron intensity measurements have been done with He-3 counters and gold foil activation methods. To measure both spatial distribution and absolute value simultaneously with high accuracy was an issue. To solve this issue, we proposed the large-area gold-foil activation method for thermal neutrons. In this presentation, we will explain the method of the large-area gold foil activation method and report examples of its application to neutron intensity and distribution measurements at BL02, BL03, and BL14.
