Neutron imaging of generated water inside polymer electrolyte fuel cell using newly-developed gas diffusion layer with gas flow channels during power generation

Nasu, Mitsunori*; Yanai, Hiroshi*; Hirayama, Naoki*; Adachi, Hironori*; Kakizawa, Yu*; Shirase, Yuto*; Nishiyama, Hiromichi*; Kawamoto, Teppei*; Inukai, Junji*; Shinohara, Takenao; et al.

Journal of Power Sources, 530, p.231251_1 - 231251_11, 2022/05

https://doi.org/10.1016/j.jpowsour.2022.231251

Shielding experiments of concrete and iron for the 244 MeV and 387 MeV quasi-mono energetic neutrons using a Bonner sphere spectrometer (at RCNP, Osaka Univ.)

Matsumoto, Tetsuro*; Masuda, Akihiko*; Nishiyama, Jun*; Iwase, Hiroshi*; Iwamoto, Yosuke; Satoh, Daiki; Hagiwara, Masayuki*; Yashima, Hiroshi*; Yashima, Hiroshi*; Shima, Tatsushi*; et al.

EPJ Web of Conferences, 153, p.08016_1 - 08016_3, 2017/09

https://doi.org/10.1051/epjconf/201715308016

Neutron energy spectra behind concrete and iron shields were measured for quasi-monoenergetic neutrons above 200 MeV using a Bonner sphere spectrometer (BSS). Quasi-monoenergetic neutrons were produced by the Li(p,xn) reaction with 246-MeV and 389-MeV protons. The response function of BSS was also measured at neutron energies from 100 MeV to 387 MeV. In data analysis, the measured response function was used and the multiple neutron scattering effect between the BSS and the shielding material was considered. The neutron energy spectra behind the concrete and iron shields were obtained by the unfolding method using the MAXED code. Ambient dose equivalents were obtained as a function of a shield thickness successfully. For the case of the 244 MeV neutron incidence, the multiple neutron scattering effect on the effective dose is large under 50 cm thickness of the concrete shield.

Info session on human networking held in Japan-IAEA Joint Nuclear Energy Management School; Aiming to develop human network among nuclear young generation in the world

Nishiyama, Jun*; Ohgama, Kazuya; Sakamoto, Tatsujiro*; Watanabe, Rin*

Nihon Genshiryoku Gakkai-Shi ATOMO, 57(2), p.123 - 125, 2015/02

no abstracts in English

Measurement of neutron energy spectra behind shields for quasi-monoenergetic neutrons generated by 246-MeV and 389-MeV protons using a Bonner sphere spectrometer

Matsumoto, Tetsuro*; Masuda, Akihiko*; Nishiyama, Jun*; Harano, Hideki*; Iwase, Hiroshi*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Yashima, Hiroshi*; Nakane, Yoshihiro; et al.

Progress in Nuclear Science and Technology (Internet), 4, p.332 - 336, 2014/04

http://www.aesj.or.jp/publication/pnst004/data/332_336.pdf

Recently, many high-energy accelerators are used for various fields. Shielding data for high-energy neutrons are therefore very important from the point of view of radiation protection in high energy accelerator facilities. However, the shielding experimental data for high energy neutrons above 100 MeV are very poor both in quality and in quantity. In this study, neutron penetration spectral fluence and ambient dose through iron and concrete shields were measured with a Bonner sphere spectrometer (BSS). Quasi-monoenergetic neutrons were produced by the Li(p,xn) reaction by bombarding a 1-cm thick Li target with 246-MeV and 389-MeV protons in the Research Center for Nuclear Physics (RCNP) of the Osaka University. Shielding materials are iron blocks with a thickness from 10 cm to 100 cm and concrete blocks with a thickness from 25 cm to 300 cm.

Characterisation of quadi-monoenergetic neutron energy spectra using Li(p,n) reactions at 246-389 MeV

Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Iwase, Hiroshi*; Yashima, Hiroshi*; Itoga, Toshiro*; Sato, Tatsuhiko; Nakane, Yoshihiro; Nakashima, Hiroshi; Sakamoto, Yukio; et al.

Proceedings of 10th Meeting of the Task Force on Shielding Aspects of Accelerators, Targets and Irradiation Facilities (SATIF-10), p.53 - 61, 2011/03

The neutron energy spectra penetrating 10 to 100 cm thick iron and 25 to 200 cm thick concrete shields have been measured using 138, 243 and 387 MeV quasi-monoenergetic neutron sources at the Research Center for Nuclear Physics (RCNP) facility, Osaka University. The source neutrons were produced from a 1 cm thick lithium target bombarded with 140, 245 and 388 MeV protons. Two types of NE213 liquid organic scintillators and Bonner ball neutron spectrometers were used for the neutron energy spectrum measurement. The TOF and unfolding methods were applied to estimate the energy spectra behind the shield in the peak energy region and continuous energy region, respectively. We have also measured the neutron energy spectra and angular distribution of the source neutron above 1 MeV in the angular range from 0 to 30 with the TOF method. All measured data were compared with the PHITS Monte Carlo calculations.

and cross sections of the C(,)O reaction at 1.2 MeV using pulsed beams

Makii, Hiroyuki; Ueda, Hitoshi*; Temma, Yasuyuki*; Nagai, Yasuki*; Shima, Tatsushi*; Fujimoto, Shinya*; Segawa, Mariko; Mishima, Kenji*; Nishiyama, Jun*; Igashira, Masayuki*

AIP Conference Proceedings 1269, p.283 - 288, 2010/10

https://doi.org/10.1063/1.3485149

The C(,)O reaction cross section plays an important role in stellar evolution at the stage of helium-burning. However, the cross section at low energy still has a large uncertainty mainly due to the poor determination of the ratio of cross section to one. Hence, we have installed new system to make a precise measurement of the cross section. In this experiment, we used the high efficiency anti-Compton NaI(Tl) spectrometers with a large S/N ratio, an intense pulsed beams, and the monitoring system of target thickness. With use of the system we succeeded in removing a background due to neutron and could clearly detect the -ray from the C(,)O reaction with high statistics. We determined the and cross section down to 1.2 MeV, and thus obtained results are compared to recent theoretical calculations.

Preliminary measurements of Np neutron capture cross section

Mizumoto, Motoharu; Oshima, Masumi; Koizumi, Mitsuo; Toh, Yosuke; Kimura, Atsushi; Harada, Hideo; Furutaka, Kazuyoshi; Kitatani, Fumito; Nakamura, Shoji; Igashira, Masayuki*; et al.

no journal, , 

Neutron capture cross section measurements of minor actinide nuclei have been carried out using a 4 Ge spectrometer. In the meeting, preliminary results of Np capture cross sections measured at the KUR electron linac TOF facility are reported.

Neutron induced reaction and Re/Os chronometer

Segawa, Mariko; Nagai, Yasuki*; Masaki, Tomohiro*; Temma, Yasuyuki*; Shima, Tatsushi*; Makii, Hiroyuki*; Mishima, Kenji*; Ueda, Hitoshi*; Nakayoshi, Akira*; Ota, Takeshi*; et al.

no journal, , 

Re-Os pair is known as the most promising nuclear cosmochronometer with considerable potential. However, there remains non-trivial problems related to an excited neutron capture reaction of Os at a stellar temperature. Firstly, Os is produced and depleted by the slow process nucleosynthesis. Hence, it is necessary to obtain both the production and depletion rates of Os. Secondly, Os is depleted not only by its ground state neutron capture reaction but also by an excited state neutron capture reaction of Os in a stellar temperature. In the present study, we have measured the neutron capture reaction cross sections for Os, Os and Os accurately and neutron inelastic scattering reaction cross section for Os off the ground state of Os to its 9.75-keV first excited statein the neutron energy range from 10 to 100 keV. The measurements of the neutron capture reactions have been carried out by detecting a prompt -ray by means fan anti-Compton NaI(Tl) spectrometer. The (n, n') reaction cross section for Os has been measured with use of four Li-glass scintillation detectors. Based on these new capture cross sections, we reestimate on the basis of a careful reaction cross section calculation the correction factor F for the neutron capture on the 9.75-keV first excited state in Os as a function of stellar temperature, as required to derive the age of the galaxy within the Re-Os chronology.

Neutron spectra and dose measurement in quasi-mono-energetic high-energy neutron fields

Mares, V.*; Pioch, C.*; Rhm, W.*; Iwase, Hiroshi*; Iwamoto, Yosuke; Hagiwara, Masayuki*; Satoh, Daiki; Matsumoto, Tetsuro*; Masuda, Akihiko*; Yashima, Hiroshi*; et al.

no journal, , 

Measurements of neutron spectra and neutron doses were performed in high-energy neutron fields at the Research Center for Nuclear Physics (RCNP), Osaka University, Japan, using two extended Bonner Sphere Spectrometers (BSS), a WENDI-II REM meter, a DARWIN dosimeter, an extended FUJI REM counter, and the time-of-flight (TOF) method employing NE213 liquid organic scintillators. The quasi-mono-energetic neutron fields were generated by the Li(p,n)Be reaction from a Li target, injected by 246 and 389 MeV protons. The BSS and TOF neutron energy spectra were folded with H*(10) fluence-to-dose conversion coefficients and the resulting values for the neutron ambient dose equivalent were compared with those directly measured by various other instruments used in this experiment. Agreement among all H*(10) neutron doses was very reasonable considering the complexity of the experiment.