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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：1 Percentile：63.33(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：63.33(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.
Iwamoto, Hiroki; Nakano, Keita; Meigo, Shinichiro; Satoh, Daiki; Iwamoto, Yosuke; Ishi, Yoshihiro*; Uesugi, Tomonori*; Kuriyama, Yasutoshi*; Yashima, Hiroshi*; Nishio, Katsuhisa; et al.
JAEA-Conf 2022-001, p.129 - 133, 2022/11
For accurate prediction of neutronic characteristics for accelerator-driven systems (ADS) and a source term of spallation neutrons for reactor physics experiments for the ADS at Kyoto University Critical Assembly (KUCA), we have launched an experimental program to measure nuclear data on ADS using the Fixed Field Alternating Gradient (FFAG) accelerator at Kyoto University. As part of this program, the proton-induced double-differential thick-target neutron-yields (TTNYs) and cross-sections (DDXs) for iron have been measured with the time-of-flight (TOF) method. For each measurement, the target was installed in a vacuum chamber on the beamline and bombarded with 107-MeV proton beams accelerated from the FFAG accelerator. Neutrons produced from the targets were detected with stacked, small-sized neutron detectors composed of the NE213 liquid organic scintillators and photomultiplier tubes, which were connected to a multi-channel digitizer mounted with a field-programmable gate array (FPGA), for several angles from the incident beam direction. The TOF spectra were obtained from the detected signals and the FFAG kicker magnet's logic signals, where gamma-ray events were eliminated by pulse shape discrimination applying the gate integration method to the FPGA. Finally, the TTNYs and DDXs were obtained from the TOF spectra by relativistic kinematics.
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：6 Percentile：69.63(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：35.09(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.
Chiaveri, E.*; Aberle, O.*; Alcayne, V.*; Kimura, Atsushi; 124 of others*
EPJ Web of Conferences, 239, p.17001_1 - 17001_8, 2020/09
Times Cited Count：4 Percentile：94.48(Nuclear Science & Technology)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.
Tsai, P.-E.; Iwamoto, Yosuke; Hagiwara, Masayuki*; Sato, Tatsuhiko; Ogawa, Tatsuhiko; Satoh, Daiki; Abe, Shinichiro; Ito, Masatoshi*; Watabe, Hiroshi*
Proceedings of 2017 IEEE Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC 2017) (Internet), 3 Pages, 2018/11
The energy spectra of primary knock-on atoms (PKAs) are essential for radiation damage assessment in design of accelerator facilities. However up to date the experimental data are still limited, due to the poor mass resolution and the high measurement threshold energies in the conventional setup of nuclear physics experiments using solid state detectors, which are typically above a few MeV/nucleon. In this study, a novel detection system consisting of two time detectors and one dE-E energy detector is proposed and being constructed to measure the PKA spectra. The system and detector design was based on Monte Carlo simulations by using the PHITS code. The PHITS simulations show that the system is able to distinguish the PKA isotopes above 
0.2-0.3 MeV/nucleon for A=2030 amu; the PKA mass identification thresholds decrease to 
0.1 MeV/nucleon for PKAs lighter than 20 amu. The detection system will be tested in the summer of 2017, and the test results will be presented at the conference.
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：10 Percentile：98.13(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：86.42(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：78 Percentile：99.04(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：25.54(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：11.62(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：26.07(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：4.69(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.
