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Nakamura, Shoji; Shibahara, Yuji*; Endo, Shunsuke; Kimura, Atsushi
Journal of Nuclear Science and Technology, 59(11), p.1388 - 1398, 2022/11
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)The present study selected Np among radioactive nuclides and aimed to measure the thermal-neutron capture cross-section for
Np in a well-thermalized neutron field by an activation method. A
Np standard solution was used for irradiation samples. A thermal-neutron flux at an irradiation position was measured with neutron flux monitors:
Sc,
Co,
Mo,
Ta and
Au. The
Np sample and flux monitors were irradiated together for 30 minutes in the graphite thermal column equipped with the Kyoto University Research Reactor. The similar irradiation was carried out twice. After the irradiations, the
Np samples were quantified using 312-keV gamma ray emitted from
Pa in a radiation equilibrium with
Np. The reaction rates of
Np were obtained from gamma-ray peak net counts given by
Np, and then the thermal-neutron capture cross-section of
Np was found to be 173.8
4.4 barn by averaging the results obtained by the two irradiations. The present result was in agreement with the reported data given by a time-of-flight method within the limit of uncertainty.
Nakamura, Shoji; Toh, Yosuke; Kimura, Atsushi; Hatsukawa, Yuichi*; Harada, Hideo
Journal of Nuclear Science and Technology, 59(7), p.851 - 865, 2022/07
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)The present study performed integral experiments of I using a fast-neutron source reactor "YAYOI" of the University of Tokyo to validate evaluated nuclear data libraries. The iodine-129 sample and flux monitors were irradiated by fast neutrons in the Glory hole of the YAYOI reactor. Reaction rates of
I were obtained by measurement of decay gamma-rays emitted from
I. The validity of the fast-neutron flux spectrum in the Glory hole was confirmed by the
ratios of the reaction rates of flux monitors. The experimental reaction rate of
I was compared with that calculated with both the fast-neutron flux spectrum and evaluated nuclear data libraries. The present study revealed that the evaluated nuclear data of
I cited in JENDL-4.0 should be reduced as much as 18% in neutron energies ranging from 10 keV to 3 MeV, and supported the reported data by Noguere
below 100 keV.
Nakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*
KURNS Progress Report 2021, P. 93, 2022/07
In terms of nuclear transmutation studies of minor actinides in nuclear wastes, the present work selected Np among them and aimed to measure the thermal-neutron capture cross-section of
Np using a well-thermalized neutron field by a neutron activation method because there have been discrepancies among reported cross-section data. A
Np standard solution was used for irradiation samples. The thermal-neutron flux at an irradiation position was measured with flux monitors:
Sc,
Co,
Mo,
Ta and
Au. The
Np sample was irradiated together with the flux monitors for 30 minutes in the graphite thermal column equipped in the Kyoto University Research Reactor. The similar irradiation was repeated once more to confirm the reproducibility of the results. After irradiation, the
Np samples were quantified using 312-keV gamma-ray emitted from
Pa in radiation equilibrium with
Np. The reaction rates of
Np were obtained from the peak net counts of gamma-rays emitted from generated
Np, and then the thermal-neutron capture cross-section of
Np was found to be 173.8
4.7 barn by averaging the results obtained by the two irradiations. The present result was in agreement with the reported data given by a time-of-flight method within a limit of uncertainty.
Maeda, Makoto; Segawa, Mariko; Toh, Yosuke; Endo, Shunsuke; Nakamura, Shoji; Kimura, Atsushi
Scientific Reports (Internet), 12(1), p.6287_1 - 6287_8, 2022/06
Times Cited Count:1 Percentile:0(Multidisciplinary Sciences)Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*; Sato, Yaoki*; et al.
Journal of Nuclear Science and Technology, 59(5), p.647 - 655, 2022/05
Times Cited Count:1 Percentile:33.13(Nuclear Science & Technology)Segawa, Mariko; Toh, Yosuke; Kai, Tetsuya; Kimura, Atsushi; Nakamura, Shoji
Annals of Nuclear Energy, 167, p.108828_1 - 108828_5, 2022/03
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Endo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Rovira Leveroni, G.; Terada, Kazushi*; Meigo, Shinichiro; Toh, Yosuke; Segawa, Mariko; et al.
Journal of Nuclear Science and Technology, 59(3), p.318 - 333, 2022/03
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Rovira Leveroni, G.; Katabuchi, Tatsuya*; Tosaka, Kenichi*; Matsuura, Shota*; Kodama, Yu*; Nakano, Hideto*; Iwamoto, Osamu; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Nobuyuki
Journal of Nuclear Science and Technology, 59(1), p.110 - 122, 2022/01
Times Cited Count:1 Percentile:33.13(Nuclear Science & Technology)Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Kodama, Yu*; Nakano, Hideto*
Journal of Nuclear Science and Technology, 11 Pages, 2022/00
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Nakamura, Shoji; Hatsukawa, Yuichi*; Kimura, Atsushi; Toh, Yosuke; Harada, Hideo
Journal of Nuclear Science and Technology, 58(12), p.1318 - 1329, 2021/12
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)The present study performed fast-neutron capture cross-section measurement of Tc by an activation method using a fast-neutron source reactor "YAYOI" of the University of Tokyo. Technetium-99 samples were irradiated with reactor neutrons using a pneumatic system. Reaction rates of
Tc were obtained by measuring decay gamma rays emitted from
Tc. The neutron flux at an irradiation position was monitored with gold foils. The fast-neutron capture cross section of
Tc at neutron energy of 85 keV was derived as 0.432
0.023 barn by using the reaction rates of
Tc, evaluated cross-section data and the fast-neutron flux spectrum of the YAYOI reactor. The present study agreed with the evaluated nuclear data library JENDL-4.0.
Kodama, Yu*; Katabuchi, Tatsuya*; Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Nobuyuki; Iwamoto, Osamu; Hori, Junichi*; Shibahara, Yuji*; et al.
Journal of Nuclear Science and Technology, 58(11), p.1159 - 1164, 2021/11
Times Cited Count:2 Percentile:56.5(Nuclear Science & Technology)Nakamura, Shoji; Shibahara, Yuji*; Endo, Shunsuke; Kimura, Atsushi
Journal of Nuclear Science and Technology, 58(10), p.1061 - 1070, 2021/10
Times Cited Count:1 Percentile:33.13(Nuclear Science & Technology)In a well-thermalized neutron field, it is principally possible to drive a thermal-neutron capture cross-section without considering an epithermal neutron component. This was demonstrated by a neutron activation method using the graphite thermal column (TC-Pn) of the Kyoto University Research Reactor. First, in order to confirm that the graphite thermal column was a well-thermalized neutron field, neutron irradiation was performed with neutron flux monitors: Au,
Co,
Sc,
Cu, and
Mo. The TC-Pn was confirmed to be extremely thermalized on the basis of Westcott's convention, because the thermal-neutron flux component took a constant value regardless of the sensitivity of each flux monitor to epithermal neutrons. Next, as a demonstration, the thermal-neutron capture cross section of
Ta(n,
)
Ta reaction was measured using the graphite thermal column, and then derived to be 20.5
0.4 barn, which supported the evaluated value of 20.4
0.3 barn. The
Ta nuclide could be useful as a flux monitor that complements the sensitivity between
Au and
Mo monitors.
Nakamura, Shoji; Endo, Shunsuke; Kimura, Atsushi; Shibahara, Yuji*
KURNS Progress Report 2020, P. 94, 2021/08
The present study selected Np among radioactive nuclides and aimed to converge a contradiction between reported thermal-neutron capture cross sections. Neutron irradiation was carried out using the graphite thermal column equipped with the Kyoto University Research Reactor. A solution equivalent to 950 Bq order of radioactivity was pipetted out of a
Np standard solution and dropped onto a fiber filter, which was then dried with an infrared lamp to prepare a
Np sample. The
Np sample was quantified using 312-keV gamma ray emitted from
Pa in a radiation equilibrium with
Np. To monitor a thermal-neutron flux component at an irradiation position, the
Np sample was irradiated together with several stable nuclides as neutron flux monitors:
Sc,
Co,
Mo,
Ta and
Au. The reaction rate of
Np was obtained from gamma-ray yields given by
Np and
Pa, and then the thermal-neutron capture cross section of
Np was derived.
Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Tsuneyama, Masayuki*; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Ebihara, Mitsuru*
Analytical Chemistry, 93(28), p.9771 - 9777, 2021/07
Times Cited Count:2 Percentile:35(Chemistry, Analytical)Kawase, Shoichiro*; Kimura, Atsushi; Harada, Hideo; Iwamoto, Nobuyuki; Iwamoto, Osamu; Nakamura, Shoji; Segawa, Mariko; Toh, Yosuke
Journal of Nuclear Science and Technology, 58(7), p.764 - 786, 2021/07
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Iwamoto, Osamu; Iwamoto, Nobuyuki; Katabuchi, Tatsuya*; Terada, Kazushi*; Kodama, Yu*; Nakano, Hideto*; et al.
Nuclear Instruments and Methods in Physics Research A, 1003, p.165318_1 - 165318_10, 2021/07
Times Cited Count:3 Percentile:71.19(Instruments & Instrumentation)Hayakawa, Takehito*; Toh, Yosuke; Kimura, Atsushi; Nakamura, Shoji; Shizuma, Toshiyuki*; Iwamoto, Nobuyuki; Chiba, Satoshi*; Kajino, Toshitaka*
Physical Review C, 103(4), p.045801_1 - 045801_5, 2021/04
Times Cited Count:0 Percentile:0.02(Physics, Nuclear)Tsuchikawa, Yusuke; Abe, Yuta; Oishi, Yuji*; Kai, Tetsuya; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto; Kimura, Atsushi; Nakamura, Shoji; Harada, Masahide; et al.
JPS Conference Proceedings (Internet), 33, p.011074_1 - 011074_6, 2021/03
In the decommissioning of the Fukushima-Daiichi (1F) Nuclear Power Plant, it is essential to understand characteristics of the melted core materials. The estimation of boride in the real debris is of great importance to develop safe debris removal plans. Hence, it is required to investigate the amount of boron in the melted core materials with nondestructive methods. Prompt gamma-ray activation analysis (PGAA) is one of the useful techniques to determine the amount of borides by means of the 478 keV prompt gamma-ray from neutron absorption reaction of boron. Moreover, it is well known that the width of the 478 keV gamma-ray peak is typically broadened due to the Doppler effect. The degree of the broadening is affected by coexisting materials, and can be recognized by the width of the prompt gamma-ray peak. As a feasibility study, the prompt gamma-ray from boride samples were measured using the ANNRI, NOBORU, and RADEN beamlines at the Materials and Life Science Experimental Facility (MLF) of Japan Proton Accelerator Complex (J-PARC).
Nakamura, Shoji; Shibahara, Yuji*; Endo, Shunsuke; Kimura, Atsushi
Journal of Nuclear Science and Technology, 58(3), p.259 - 277, 2021/03
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Research and development were made for accuracy improvement of neutron capture cross section data on Am among minor actinides. First, the emission probabilities of decay
rays were obtained with high accuracy, and the amount of the ground state of
Am produced by reactor neutron irradiation of
Am was examined by
-ray measurement. Next, the total amount of isomer and ground states was examined by
-ray measurement. Thermal-neutron capture cross sections and resonance integrals were derived both for the
Am(n,
)
Am and for
Am(n,
)
Am reactions.
Go, Shintaro*; Ideguchi, Eiji*; Yokoyama, Rin*; Aoi, Nori*; Azaiez, F.*; Furutaka, Kazuyoshi; Hatsukawa, Yuichi; Kimura, Atsushi; Kisamori, Keiichi*; Kobayashi, Motoki*; et al.
Physical Review C, 103(3), p.034327_1 - 034327_8, 2021/03
Times Cited Count:3 Percentile:68.98(Physics, Nuclear)