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Hironaka, Kota; Lee, J.; Koizumi, Mitsuo; Ito, Fumiaki*; Hori, Junichi*; Terada, Kazushi*; Sano, Tadafumi*
Nuclear Instruments and Methods in Physics Research A, 1054, p.168467_1 - 168467_5, 2023/09
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)
Sr/Y and 
Cs radioactivityTerasaka, Yuta; Uritani, Akira*
Nuclear Instruments and Methods in Physics Research A, 1049, p.168071_1 - 168071_7, 2023/04
Times Cited Count：0 Percentile：0.02(Instruments & Instrumentation)
TaEndo, Shunsuke; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki; Rovira Leveroni, G.; Toh, Yosuke; Segawa, Mariko; Maeda, Makoto
Nuclear Science and Engineering, 18 Pages, 2023/00
Times Cited Count：1 Percentile：72.91(Nuclear Science & Technology)Collaborative Laboratories for Advanced Decommissioning Science; Nagoya University*
JAEA-Review 2022-033, 80 Pages, 2022/12
JAEA-Review-2022-033.pdf:4.08MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station (1F), Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Measurement methods for the radioactive source distribution inside reactor buildings using a one-dimensional optical fiber radiation sensor" conducted from FY2019 to FY2021. Since the final year of this proposal was FY2021, the results for three fiscal years were summarized. The present study aims to develop an optical fiber type radiation sensor that can measure the radiation distribution one-dimensionally along the fiber under a high radiation field for the decommissioning of 1F. Based on the conventional time-of-flight method, we found several promising sensor candidates for the radiation distribution measurement under high dose rate and many scattered gamma-rays.
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：5 Percentile：65.59(Nuclear Science & Technology)Collaborative Laboratories for Advanced Decommissioning Science; Nagoya University*
JAEA-Review 2021-033, 55 Pages, 2021/12
JAEA-Review-2021-033.pdf:2.9MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2020. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Measurement methods for the radioactive source distribution inside reactor buildings using a one-dimensional optical fiber radiation sensor" conducted in FY2020. We are developing a one-dimensional optical fiber radiation sensor that can estimate the radioactive source distribution "along lines" instead of "at points". To improve the conventional time-of-flight optical fiber radiation sensor for the application under high dose rate environment, basic evaluation tests were conducted using various optical fibers with different diameters and materials.
Collaborative Laboratories for Advanced Decommissioning Science; Nagoya University*
JAEA-Review 2020-063, 44 Pages, 2021/01
JAEA-Review-2020-063.pdf:2.55MB
JAEA/CLADS had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project in FY2019. Among the adopted proposals in FY2019, this report summarizes the research results of the "Measurement methods for the radioactive source distribution inside reactor buildings using a one-dimensional optical fiber radiation sensor" conducted in FY2019.
for a mercury target induced by 3-GeV protonsMatsuda, Hiroki; Iwamoto, Hiroki; Meigo, Shinichiro; Takeshita, Hayato*; Maekawa, Fujio
Nuclear Instruments and Methods in Physics Research B, 483, p.33 - 40, 2020/11
Times Cited Count：3 Percentile：36.4(Instruments & Instrumentation)A thick target neutron yield for a mercury target at an angle of 180 from the incident beam direction is measured with the time-of-flight method using a 3-GeV proton beam at the Japan Proton Accelerator Research Complex (J-PARC). Comparing the experimental result with a Monte Carlo particle transport simulation by the Particle and Heavy Ion Transport code System (PHITS) shows that there are apparent discrepancies. We find that this trend is consistent with an experimental result of neutron-induced re- action rates obtained using indium and niobium activation foils. Comparing proton-induced neutron-production double-differential cross-sections for a lead target at backward directions between the PHITS calculation and experimental data suggests that the dis- crepancies for our experiments would be linked to the neutron production calculation around 3 GeV by the PHITS spallation model and/or the calculation of nonelastic cross-sections around 3 GeV in the particle transport simulation.
Okita, Shoichiro; Tasaki, Seiji*; Abe, Yutaka*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 19(3), p.178 - 184, 2020/09
The Kyoto University Accelerator-based Neutron Source (KUANS) is a compact neutron source that is mainly used for spectrometer and detector development. In addition, it is also suited for experiments to study the neutronic design of moderators owing to the relatively low neutron generation yield by 
Be(p,n). We present a neutronic design of the neutron moderator on a reentrant-hole configuration for KUANS to enhance the neutron emission, and some experiments are conducted at KUANS for verification. A polyethylene moderator on a reentrant-hole configuration is designed by PHITS calculation and is introduced to KUANS to obtain intense oblong neutron beams. The intensity of the pulsed neutron beam is experimentally measured. The results reveal that the intensity becomes approximately 1.9 times stronger than that of the conventional rectangular design. In addition, the ratio of its intensity to the conventional intensity increases to approximately threefold as the neutron wavelength increases. It is interesting to note that the longer the neutron wavelength, the more efficiently they are extracted from the inside of the moderator owing to the existence of the reentrant-hole configuration.
Paradela, C.*; Heyse, J.*; Kopecky, S.*; Schillebeeckx, P.*; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi
EPJ Web of Conferences, 146, p.09002_1 - 09002_4, 2017/09
Times Cited Count：9 Percentile：97.81(Nuclear Science & Technology)
Be(n, 
) reaction at n_TOFCosentino, L.*; Musumarra, A.*; Barbagallo, M.*; Pappalardo, A.*; Harada, Hideo; Kimura, Atsushi; n_TOF Collaboration*; 126 of others*
Nuclear Instruments and Methods in Physics Research A, 830, p.197 - 205, 2016/09
Times Cited Count：19 Percentile：86.84(Instruments & Instrumentation)Wei
, C.*; Chiaveri, E.*; Girod, S.*; Vlachoudis, V.*; Harada, Hideo; Kimura, Atsushi; n_TOF Collaboration*; 126 of others*
Nuclear Instruments and Methods in Physics Research A, 799, p.90 - 98, 2015/11
Times Cited Count：76 Percentile：99.02(Instruments & Instrumentation)Tsuchiya, Harufumi; Koizumi, Mitsuo; Kitatani, Fumito; Kureta, Masatoshi; Harada, Hideo; Seya, Michio; Heyse, J.*; Kopecky, S.*; Mondelaers, W.*; Paradela, C.*; et al.
Proceedings of 37th ESARDA Annual Meeting (Internet), p.846 - 851, 2015/08
One of non-destructive techniques using neutron resonance reaction is neutron resonance transmission analysis (NRTA). We are presently developing a new active neutron non-destructive method including NRTA in order to detect and quantify special nuclear materials (SNMs) in nuclear fuels containing MA. We aim at applying the technique to not only particle-like debris but also other materials in high radiation field. For this aim, we make use of fruitful knowledge of neutron resonance densitometry (NRD) that was developed for particle-like debris in melted fuel. NRTA detects and quantifies SNMs by means of analyzing a neutron transmission spectrum via a resonance shape analysis. In this presentation, we explain the basic of NRTA and its role in the active neutron technique. Then, with knowledge obtained in the development of NRD, we discuss items to be investigated for NRTA in our active neutron technique.
Harada, Hideo; Kimura, Atsushi; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*
Journal of Nuclear Science and Technology, 52(6), p.837 - 843, 2015/06
Times Cited Count：3 Percentile：25.85(Nuclear Science & Technology)Sekiguchi, Tetsuhiro; Baba, Yuji; Shimoyama, Iwao; Wu, G.*; Kitajima, Yoshinori*
Surface Science, 593(1-3), p.310 - 317, 2005/11
Times Cited Count：2 Percentile：11.66(Chemistry, Physical)Using a newly developed rotatable time-of-flight mass spectrometer(R-TOF-MS) and polarized synchrotron radiation, orientation effect on fragmentation and desorption pathways occurring at the top-most layers of molecular solids have been investigated. Reported will be polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed chlorobenzene.
Ikeura, Hiromi*; Sekiguchi, Tetsuhiro; Baba, Yuji; Imamura, Motoyasu*; Matsubayashi, Nobuyuki*; Shimada, Hiromichi*
Surface Science, 593(1-3), p.303 - 309, 2005/11
Times Cited Count：5 Percentile：26.14(Chemistry, Physical)no abstracts in English
W/cm
intensity by focusing wavefront corrected 100 TW, 10 Hz laser pulsesAkahane, Yutaka; Ma, J.; Fukuda, Yuji; Aoyama, Makoto; Kiriyama, Hiromitsu; Inoue, Norihiro*; Tsuji, Koichi*; Nakai, Yoshiki*; Yamamoto, Yoichi*; Sheldakova, J. V.*; et al.
Japanese Journal of Applied Physics, Part 1, 44(8), p.6087 - 6089, 2005/08
Times Cited Count：1 Percentile：4.7(Physics, Applied)An improvement of laser-focused peak intensity has been achieved in a JAERI 100 TW Ti:sapphire chirped-pulse amplifier chain with a feedback-controlled adaptive optics system. Measurements of optical parameters of the laser pulse and an experimental tunneling ionization ratio of a rare gas atom with laser energy scaling have practically confirmed an ultrarelativistic intensity of over 10 W/cm operating at a 10 Hz repetition rate.
Katayama, Atsushi; Furukawa, Katsutoshi; Watanabe, Kazuo
Bunseki Kagaku, 52(6), p.461 - 467, 2003/06
Times Cited Count：0 Percentile：0.01(Chemistry, Analytical)An imaging ion detection system was introduced to a time-of-flight mass spectrometer (TOFMS) in order to increase dynamic range in the isotope ratio measurements. The new detection system utilizes a position sensitive micro channel plate (MCP) with a phosphor plate and a CCD camera which records light spots on the MCP. Mass discriminated ion beams produced by laser resonance ionization were swept on the surface of MCP by a time-depended electric field located in front of the MCP. The resulting light spots were recorded as images by CCD camera. A mass spectrum was obtained from the images. The present method was applied to the isotope analysis of calcium. A dynamic range of more than 5 orders of magnitude was achieved.
Sekiguchi, Tetsuhiro; Ikeura, Hiromi*; Baba, Yuji
Surface Science, 532-535(1-3), p.1079 - 1084, 2003/06
Using a newly developed rotatable time-of-flight mass spectrometer(R-TOF-MS) and polarized synchrotron radiation, we have investigated orientation effect on fragmentation and desorption pathways occurring at the top-most layers of molecular solids. Reported will be polarization-angle dependencies of TOF mass spectra, high-resolution electron- and ion-NEXAFS in condensed formic acid, formamide and benzene. For condensed formamide(HCOND
), marked orientation effect was observed for the enhanced H
-yields following C1s 
*
resonance. Direct photodissociation and charge-neutralization play an important role in the effect. For some fragment species, however, the bond scission showed no polarization dependence when dissociation sites were far from core-excited atoms. This is the case for N-D scission and D-desorption following C1s excitation, suggesting that indirect process governs, where secondary electrons would induce the fragmentation.
Miura, Yukitoshi; Okano, Fuminori; Suzuki, Norio; Mori, Masahiro; Hoshino, Katsumichi; Maeda, Hikosuke; Takizuka, Tomonori; JFT-2M Group; Ito, Sanae*; Ito, Kimitaka
Physical Review Letters, 69(15), p.2216 - 2219, 1992/10
Times Cited Count：28 Percentile：78.66(Physics, Multidisciplinary)no abstracts in English
