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Wallerberger, M.*; Badr, S.*; Hoshino, Shintaro*; Huber, S.*; Kakizawa, Fumiya*; Koretsune, Takashi*; Nagai, Yuki; Nogaki, Kosuke*; Nomoto, Takuya*; Mori, Hitoshi*; et al.
Software X (Internet), 21, p.101266_1 - 101266_7, 2023/02
Times Cited Count：8 Percentile：88.45(Computer Science, Software Engineering)no abstracts in English
VAl probed by soft X-ray spectroscopiesNagai, Kodai*; Fujiwara, Hidenori*; Aratani, Hidekazu*; Fujioka, Shuhei*; Yomosa, Hiroshi*; Nakatani, Yasuhiro*; Kiss, Takayuki*; Sekiyama, Akira*; Kuroda, Fumiaki*; Fujii, Hitoshi*; et al.
Physical Review B, 97(3), p.035143_1 - 035143_8, 2018/01
Times Cited Count：21 Percentile：70.17(Materials Science, Multidisciplinary)We have studied the electronic structure of ferrimagnetic MnVAl single crystals by means of soft X-ray absorption spectroscopy (XAS), X-ray absorption magnetic circular dichroism (XMCD), and resonant soft X-ray inelastic scattering (RIXS). We have successfully observed the XMCD signals for all the constituent elements. The Mn L
XAS and XMCD spectra are reproduced by spectral simulations based on density-functional theory, indicating the itinerant character of the Mn 3
states. On the other hand, the V 3 electrons are rather localized since the ionic model can qualitatively explain the V L XAS and XMCD spectra. This picture is consistent with local 
excitations revealed by the V L
RIXS.
Yasuda, Ryo; Nitto, Koichi*; Konagai, Chikara*; Shiozawa, Masahiro*; Takenaka, Nobuyuki*; Asano, Hitoshi*; Murakawa, Hideki*; Sugimoto, Katsumi*; Nojima, Takehiro; Hayashida, Hirotoshi; et al.
Nuclear Instruments and Methods in Physics Research A, 651(1), p.268 - 272, 2011/09
Times Cited Count：7 Percentile：48.91(Instruments & Instrumentation)Neutron radiography is one of useful tools to visualize water behavior in fuel cells under operation. In order to observe the detailed information about the water distribution in MEA and GDL in fuel cells, a high spatial resolution and high sensitivity neutron imaging system are required. We developed an imaging system using the neutron color imaging intensifier and continuously observed water distribution in operating a fuel cell. By using the system, a small type fuel cell under operation was continuously observed at the TNRF in every 20 sec. In the results, the water area was appeared from GDL and MEA, and expanded to the channel of the cathode side. On the other hand, voltage was gradually reduced with the operation time, and steeply dropped. It is considered that voltage drop was caused by blockage of gas flow due to the piling up water in the channel of the cathode side.
and 
cross sections of the 
C(
,
)
O reaction at 
1.2 MeV using pulsed beamsMakii, 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
Times Cited Count：0 Percentile：0.02(Astronomy & Astrophysics)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.
and cross sections of the C
O reaction using pulsed beamsMakii, Hiroyuki; Nagai, Yasuki*; Shima, Tatsushi*; Segawa, Mariko; Mishima, Kenji*; Ueda, Hitoshi*; Igashira, Masayuki*; Osaki, Toshiro*
Physical Review C, 80(6), p.065802_1 - 065802_16, 2009/10
Times Cited Count：32 Percentile：83.95(Physics, Nuclear)We measured the -ray angular distribution from CO to the ground state of O using a pulsed beam at 
and 1.4 MeV. True events of CO were discriminated from background events due to neutrons from 
C(
)O with a time-of-flight method. The obtained -ray spectrum with anti-Compton NaI(Tl) spectrometers showed a characteristic line shape from CO: the Doppler broadening and energy loss of particles in C targets. The astrophysical S factors for and , 
and 
, derived from the present cross sections are in excellent agreement with the values derived by 
-matrix calculation of the 
-delayed spectrum of N, and by using the asymptotic normalization constant in the -matrix fit.
and cross sections of the C(
O reaction at 
1.4 MeV using pulsed beamsMakii, Hiroyuki; Nagai, Yasuki; Mishima, Kenji*; Segawa, Mariko; Shima, Tatsushi*; Ueda, Hitoshi; Igashira, Masayuki*
AIP Conference Proceedings 1016, p.215 - 220, 2008/05
The C(O reaction 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. We have installed a new system to measure the -ray angular distribution of the C(O reaction to accurately determine the 
and 
. In this experiment, we used high efficiency anti-Compton NaI(Tl) spectrometers to detect a -ray from the reaction with a large S/N ratio, intense pulsed beams to discriminate true events from neutron induced background with a time-of-flight method, and the monitoring system of target thickness. We succeeded in removing a background due to neutrons and could clearly detect the -ray from the C(O reaction with high statics.
Rn and its decay products coupled with a mesoscale meteorological model, 1; Model description and validationNishizawa, Masato; Nagai, Haruyasu; Chino, Masamichi; Moriizumi, Jun*; Yoshioka, Katsuhiro*; Okura, Takehisa; Yamazawa, Hiromi*; Iida, Takao*; Mukai, Hitoshi*; Tojima, Yasunori*; et al.
Journal of Nuclear Science and Technology, 44(11), p.1458 - 1466, 2007/11
Times Cited Count：5 Percentile：37.19(Nuclear Science & Technology)A three-dimensional Eulerian numerical model for Rn and its decay products coupled with a mesoscale meteorological model has been developed and applied to the reproduction of the daily and monthly variations of Rn concentration, the monthly variation of 
Pb deposition in Japan and the temporal variation of dose rate after the cold front passage in the coastal area of the Japan Sea for the verification of model capability. The results are as follows: (1) The model reproduced the monthly variation of surface Rn concentration in remote islands, but underestimated inland concentration due to coarse vertical resolution near the surface of the model. (2) The model reproduced the seasonal variation of the observed and the long-term yearly averaged Pb depositions as long as precipitations are predicted precisely. (3) The model reproduced the rise of dose rate in precipitation accompanied with the cold front passage. In particular, Rn decay products in melted snow and graupel contributed the rise of dose rate.
Ge spectrometerKoizumi, Mitsuo; Osa, Akihiko; Toh, Yosuke; Kimura, Atsushi; Mizumoto, Motoharu; Oshima, Masumi; Igashira, Masayuki*; Osaki, Toshiro*; Harada, Hideo*; Furutaka, Kazuyoshi*; et al.
Nuclear Instruments and Methods in Physics Research A, 562(2), p.767 - 770, 2006/06
Times Cited Count：6 Percentile：43.85(Instruments & Instrumentation)In order to measure the neutron capture cross section of minor actinides, we have proposed the use of a 4 Ge spectrometer. A Time-of-Flight neutron beam line for the experiment has been constructed at the KURRI electron LINAC. The assembling of the 4 Ge spectrometer is in progress. We are also developing a new data acquisition system based on a digital processing technique.
Nagai, Takayuki; Kobayashi, Yuichi*; Tanaka, Hitoshi*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(3), p.242 - 248, 2004/00
None
Nagai, Takayuki; Kameshiro, Naoki*; Kobayashi, Yuichi*; Tanaka, Hitoshi*; Tayama, Toshimitsu; Myochin, Munetaka
Nihon Genshiryoku Gakkai Wabun Rombunshi, 2(3), p.269 - 278, 2003/09
None
-rayOkagawa, Seigo; Nagai, Hitoshi*; Abe, Hitoshi*; Tashiro, Shinsuke
JAERI-Tech 2003-068, 17 Pages, 2003/08
JAERI-Tech-2003-068.pdf:0.78MB
To study the release mechanism of iodine from the dissolver solution in the nuclear fuel reprocessing plants to the atmosphere at criticality accidents, the characteristics of redox of iodine species in various solutions must be examined. In the present work, the effect of -ray irradiation on the redox reaction was examined in the nitric acid solution of 1M and 3M. Without irradiation, most of iodine in 1M nitric acid solutions were exist in the form of I
. In 3M nitric acid solutions, iodine was oxidized to I. When the solutions were irradiated by -ray with exposure of more than 4C/kg, I was disappeared regardless of nitric acid concentration. At exposure of 120C/kg, iodine was oxidized to IO. At exposure of 4800C/kg, iodine was exist in the form of IO in 1M nitric acid solution. On the other hand, iodine in 3M nitric acid solution was reduced to I at the same exposure. In the irradiated solution, nitrous acid was found, which would be produced from nitric acid by -ray irradiation.
Abe, Hitoshi; Tashiro, Shinsuke; Nagai, Hitoshi; Koike, Tadao; Okagawa, Seigo; Murata, Mikio
JAERI-Tech 99-067, p.23 - 0, 1999/09
no abstracts in English
Fujine, Sachio; Murata, Mikio; Abe, Hitoshi; Takada, Junichi; Tsukamoto, Michio; Miyata, Teijiro*; Ida, Masaaki*; Watanabe, Makio; Uchiyama, Gunzo; Asakura, Toshihide; et al.
JAERI-Research 99-056, p.278 - 0, 1999/09
JAERI-Research-99-056.pdf:22.73MB
no abstracts in English
and 
of the C(, )O reaction obtained at E
= 1.6 and 1.4 MeVMakii, Hiroyuki; Nagai, Yasuki*; Shima, Tatsushi*; Segawa, Mariko; Ueda, Hitoshi*; Masaki, Tomohiro*; Mishima, Kenji*; Igashira, Masayuki*; Osaki, Toshiro*
no journal, ,
no abstracts in English
Segawa, Mariko; Nagai, Yasuki*; Masaki, Tomohiro*; Shima, Tatsushi*; Makii, Hiroyuki; Mishima, Kenji*; Ueda, Hitoshi*; Temma, Yasuyuki*; Igashira, Masayuki*; Osaki, Toshiro*; et al.
no journal, ,
no abstracts in English
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.
Ijiri, Yuji*; Shindo, Akihisa*; Miura, Hitoshi*; Kamemura, Katsumi*; Tomoe, Naoto*; Nagai, Norihisa*; Abe, Akimasa*; Fujita, Tomoo; Izumi, Atsushi
no journal, ,
no abstracts in English
Yasuda, Ryo; Sakai, Takuro; Nojima, Takehiro; Iikura, Hiroshi; Matsubayashi, Masahito; Nitto, Koichi*; Konagai, Chikara*; Shiozawa, Masahiro*; Murakawa, Hideki*; Sugimoto, Katsumi*; et al.
no journal, ,
Polymer electrolyte fuel cells (PEFC) are expected as one of the clean energy sources in next generation. The water management is one of important subjects for enhance of stability and durability of the PEFC. Neutron radiography is one of useful tools to visualize water behavior in operating fuel cells. In order to observe the detailed information about the water distribution in fuel cells, we developed an imaging system using a neutron color image intensifier which is novel neutron image detector with high spatial resolution and high sensitivity. By using the imaging system, the water distribution in a small sized fuel cell during operation was visualized. In this paper we would report results and discussion about correlation between the water behavior and fuel cell performance.
C(,)O reaction at E = 1.2 and 1.5 MeV using pulsed beamMakii, Hiroyuki; Ueda, Hitoshi*; Nagai, Yasuki*; Segawa, Mariko; Temma, Yasuyuki*; Shima, Tatsushi*; Mishima, Kenji*; Igashira, Masayuki*
no journal, ,
The C(,)O reaction plays an important role in stellar evolution at the stage of He-burning. However the cross section at the stellar temperature still has a large uncertainty mainly due to the poor determination of the cross section ratio, . In order to make a precise measurement of the , we have installed a new measurement system of the -ray angular distributions of the C(,)O reaction. In this experiment, we used high efficiency anti-Compton NaI(Tl) spectrometers to detect -rays from the reaction with a large S/N ratio, an intense pulsed beams, and the monitoring system of the target thickness. With use of the system we succeeded in removing a background due to neutrons and could clearly detect the -ray from the reaction with high statistics. We determined the E1 and E2 cross section down to E = 1.2 MeV, and thus obtained results are compared to recent theoretical calculations.
