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Terada, Kentaro*; Ninomiya, Kazuhiko*; Sato, Akira*; Tomono, Dai*; Kawashima, Yoshitaka*; Inagaki, Makoto*; Nambu, Akihiro*; Kudo, Takuto*; Osawa, Takahito; Kubo, Kenya*
Journal of Analytical Science and Technology, 15, p.28_1 - 28_7, 2024/05
Times Cited Count：1 Percentile：65.87(Chemistry, Analytical)In Earth and planetary science, Pb isotopic composition is well known to play a key role in deciphering the origin and evolution of materials because they provide unique chronological and/or indigenous regional information as a radiogenic daughter nuclide from U and Th. To determine such an isotopic composition, a mass spectrometer has been widely used over several decades, which requires a destructive treatment such as laser ablation and thermal ionization, so on. Here we first report the non-destructive Pb isotopic measurement of the natural galena (PbS) using an energy-shift of muon-induced characteristic X-rays. The observed Pb isotopic composition of the natural galena is in good agreement with that obtained by conventional mass spectrometry.
Mizuno, Rurie*; Niikura, Megumi*; Saito, Takeshi*; Matsuzaki, Teiichiro*; Sakurai, Hiroyoshi*; Amato, A.*; Asari, Shunsuke*; Biswas, S.*; Chiu, I.-H.; Gianluca, J.*; et al.
Nuclear Instruments and Methods in Physics Research A, 1060, p.169029_1 - 169029_14, 2024/03
Times Cited Count：1 Percentile：35.91(Instruments & Instrumentation)Takayanagi, Tomohiro; Ono, Ayato; Sugita, Moe; Yamamoto, Kazami; Oguri, Hidetomo; Kinsho, Michikazu; Horino, Koki*; Ueno, Tomoaki*; Oda, Kodai*; Tokuchi, Akira*; et al.
Journal of Physics; Conference Series, 2687(8), p.082021_1 - 082021_7, 2024/01
Times Cited Count：0 Percentile：0.00(Physics, Atomic, Molecular & Chemical)A new kicker power supply using SiC-MOSFETs is under development at J-PARC. The base circuit uses an induction voltage superposition circuit of the LTD method, and the semiconductor module circuit consists of a radial symmetry type that achieves low noise. The three main parts of an existing kicker power supply, the thyratron, PFN circuit, and end clipper, can be configured in a single module circuit. The power supply consists of a main circuit module board that forms a trapezoidal pulse and a correction circuit module board that compensates for droop of the flat section. The thirty-two main circuit module boards and twenty correction circuit module boards are connected in series in a hierarchical manner to achieve the waveform specifications required for J-PARC RCS kicker power supplies. In addition, an insulating cylinder for conductors has been developed that suppresses corona discharge and withstands continuous operation for long periods of time.
Koyama, Shinichi; Ikeuchi, Hirotomo; Mitsugi, Takeshi; Maeda, Koji; Sasaki, Shinji; Onishi, Takashi; Tsai, T.-H.; Takano, Masahide; Fukaya, Hiroyuki; Nakamura, Satoshi; et al.
Hairo, Osensui, Shorisui Taisaku Jigyo Jimukyoku Homu Peji (Internet), 216 Pages, 2023/11
In FY 2021 and 2022, JAEA perfomed the subsidy program for "the Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy, Thermal Bahavior Estimation, and Simplified Analysis of Fuel Debris)" started in FY 2021. This presentation material summarized the results of the project, which will be available shortly on the website of Management Office for the Project of Decommissioning, Contaminated Water and Treated Water Management.
Ono, Ayato; Takayanagi, Tomohiro; Fuwa, Yasuhiro; Shinozaki, Shinichi; Ueno, Tomoaki*; Horino, Koki*; Sugita, Moe; Yamamoto, Kazami; Kinsho, Michikazu; Ikoma, Naoya*; et al.
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.871 - 876, 2023/11
In J-PARC, an ignitron is used for the crowbar device of the klystron power supply to excite the RF acceleration voltage in a Linac cavity. Mercury, that is used in the ignitron, would be prohibition of use in the future due to environmental protection. Therefore, we designed a semiconductor crowbar switch for short-circuit protection of klystron using a MOS gate thyristor. We have manufactured an oval-type board module that realizes an operating output of 3kV, 40kA, and 50us per board. Because a high voltage of 120 kV is applied on each board, we adopted a self-power supply method to supply a electricity for the control system. This method can create the electricity from a high-voltage DCDC converter. We confirmed the operating performance on a 1/2 scale (60 kV, 40 kA) of the voltage in the existing ignitron system (120 kV, 40 kA). We also studied a test circuit in a higher voltage range of more than 90 kV. Our latest result is well promising for an alternative system of ignitron.
Takayanagi, Tomohiro; Ono, Ayato; Horino, Koki*; Ueno, Tomoaki*; Sugita, Moe; Kinsho, Michikazu; Tokuchi, Akira*; Ikoma, Naoya*; Nakata, Kyosuke*; Kamezaki, Hiroaki*; et al.
Proceedings of 20th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.235 - 239, 2023/08
The kicker system used for injection and extraction of accelerated beams requires a pulsed power supply with high speed and high repetition rate of short pulses acting only on a specified bunch of beams. We have developed a semiconductor switch power supply with a rated output of 40kV/2kA using SiC-MOSFETs, one of the next-generation power semiconductors. Then, we reconfigured this semiconductor switch power supply into two units with 20kV/2kA output and conducted energization tests using an actual kicker electromagnet. It was also demonstrated with magnetic field waveforms that the flat-top correction function of this power supply can suppress ringing in the waveform by less than half. This achievement enables the reduction of the kick angle difference caused by ringing, which is a factor in beam loss. In the presentation, specifications, test equipment, and evaluation results of the developed SiC semiconductor switch power supply will be reported.
Ono, Ayato; Takayanagi, Tomohiro; Fuwa, Yasuhiro; Shinozaki, Shinichi; Ueno, Tomoaki*; Horino, Koki*; Sugita, Moe; Yamamoto, Kazami; Kinsho, Michikazu; Ikoma, Naoya*; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.395 - 399, 2023/01
At J-PARC, an ignitron is used for the crowbar device of the klystron power supply for high-frequency acceleration of a linear accelerator. Ignitron uses mercury, which is of limited use worldwide, and is expected to be discontinued in the future. Therefore, we designed a semiconductor crowbar switch for short-circuit protection of klystron using a MOS gate thyristor. We have manufactured an oval-type board module that realizes an operating output of 3 kV, 40 kA, and 50 
s per board. For the control power supply to each board module assuming a high voltage of 120 kV, we adopted a self-power supply method that creates a control power supply with a high-voltage DCDC converter from the voltage shared and charged by each board module. It was possible to confirm the operating performance on a 1/2 scale (60 kV, 40 kA) against the voltage of the existing equipment (120 kV, 40 kA) by connecting twenty oval board modules in series. The output test result will be reported.
Oda, Kodai; Takayanagi, Tomohiro; Ono, Ayato; Horino, Koki*; Ueno, Tomoaki*; Sugita, Moe; Morishita, Takatoshi; Iinuma, Hiromi*; Tokuchi, Akira*; Kamezaki, Hiroaki*; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.610 - 614, 2023/01
Kicker system is being used to kick the accelerated 3 GeV beam into the transport lines in RCS of J-PARC. The current kicker power supply applies thyratrons to discharge switches. We are developing a new kicker power supply using next-generation power semiconductors. The timing of the semiconductor switch operation is determined by the input of an external trigger signal. Large timing jitter causes unstable output pulses and beam loss due to beam orbit deviate from reference orbit. Therefore, a low jitter circuit that achieves high repeatability of 2 ns or less will be developed for the new kicker power supply. A prototype trigger generator has been fabricated, and jitter has been evaluated. The results of the evaluation test and the circuit configuration plan for reducing jitter will be reported.
Takayanagi, Tomohiro; Ono, Ayato; Fuwa, Yasuhiro; Shinozaki, Shinichi; Horino, Koki*; Ueno, Tomoaki*; Sugita, Moe; Yamamoto, Kazami; Oguri, Hidetomo; Kinsho, Michikazu; et al.
Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.242 - 246, 2023/01
At J-PARC, semiconductor short pulse power supplies to replace kicker power supplies and semiconductor long pulse power supplies to replace klystron power supply systems are under construction. We have fabricated a 40kV/2kA/1.2s unit power supply that employs a linear transformer drivers (LTD) system for kickers. Currently, we are working on a high voltage insulating cylinder insulator that suppresses corona discharges using only the insulator structure, without using insulating oil. In addition, the MARX system was adopted for klystron power supply system. A main circuit unit for 8kV/60A/830s rectangular pulse output and an 800V/60A correction circuit unit that improves the flat top droop from 10% to 1% were manufactured. Furthermore, a 2.2kV/2.4kW high voltage SiC inverter charger has been fabricated for this MARX power supply. The presentation will report the evaluation results of each test and prospects for semiconductor pulse power supplies.
Walter, H.*; Colonna, M.*; Cozma, D.*; Danielewicz, P.*; Ko, C. M.*; Kumar, R.*; Ono, Akira*; Tsang, M. Y. B*; Xu, J.*; Zhang, Y.-X.*; et al.
Progress in Particle and Nuclear Physics, 125, p.103962_1 - 103962_90, 2022/07
Times Cited Count：76 Percentile：96.00(Physics, Nuclear)Transport models are the main method to obtain physics information on the nuclear equation of state and in-medium properties of particles from low to relativistic-energy heavy-ion collisions. The Transport Model Evaluation Project (TMEP) has been pursued to test the robustness of transport model predictions to reach consistent conclusions from the same type of physical model. To this end, calculations under controlled conditions of physical input and set-up were performed by the various participating codes. These included both calculations of nuclear matter in a periodic box, which test individual ingredients of a transport code, and calculations of complete collisions of heavy ions. Over the years, five studies were performed within this project. They show, on one hand, that in box calculations the differences between the codes can be well understood and a convergence of the results can be reached. These studies also highlight the systematic differences between the two families of transport codes, known under the names of Boltzmann-Uehling-Uhlenbeck (BUU) and Quantum Molecular Dynamics (QMD) type codes. On the other hand, there still exist substantial differences when these codes are applied to real heavy-ion collisions. The results of transport simulations of heavy-ion collisions will have more significance if codes demonstrate that they can verify benchmark calculations such as the ones studied in these evaluations.
Koyama, Shinichi; Nakagiri, Toshio; Osaka, Masahiko; Yoshida, Hiroyuki; Kurata, Masaki; Ikeuchi, Hirotomo; Maeda, Koji; Sasaki, Shinji; Onishi, Takashi; Takano, Masahide; et al.
Hairo, Osensui Taisaku jigyo jimukyoku Homu Peji (Internet), 144 Pages, 2021/08
JAEA performed the subsidy program for the "Project of Decommissioning and Contaminated Water Management (Development of Analysis and Estimation Technology for Characterization of Fuel Debris (Development of Technologies for Enhanced Analysis Accuracy and Thermal Behavior Estimation of Fuel Debris))" in 2020JFY. This presentation summarized briefly the results of the project, which will be available shortly on the website of Management Office for the Project of Decommissioning and Contaminated Water Management.
Takahashi, Atsushi*; Chiba, Mirei*; Tanahara, Akira*; Aida, Jun*; Shimizu, Yoshinaka*; Suzuki, Toshihiko*; Murakami, Shinobu*; Koarai, Kazuma; Ono, Takumi*; Oka, Toshitaka; et al.
Scientific Reports (Internet), 11(1), p.10355_1 - 10355_11, 2021/05
Times Cited Count：9 Percentile：45.21(Multidisciplinary Sciences)Kitazato, Kohei*; Milliken, R. E.*; Iwata, Takahiro*; Abe, Masanao*; Otake, Makiko*; Matsuura, Shuji*; Takagi, Yasuhiko*; Nakamura, Tomoki*; Hiroi, Takahiro*; Matsuoka, Moe*; et al.
Nature Astronomy (Internet), 5(3), p.246 - 250, 2021/03
Times Cited Count：51 Percentile：96.49(Astronomy & Astrophysics)Here we report observations of Ryugu's subsurface material by the Near-Infrared Spectrometer (NIRS3) on the Hayabusa2 spacecraft. Reflectance spectra of excavated material exhibit a hydroxyl (OH) absorption feature that is slightly stronger and peak-shifted compared with that observed for the surface, indicating that space weathering and/or radiative heating have caused subtle spectral changes in the uppermost surface. However, the strength and shape of the OH feature still suggests that the subsurface material experienced heating above 300 
C, similar to the surface. In contrast, thermophysical modeling indicates that radiative heating does not increase the temperature above 200 C at the estimated excavation depth of 1 m, even if the semimajor axis is reduced to 0.344 au. This supports the hypothesis that primary thermal alteration occurred due to radiogenic and/or impact heating on Ryugu's parent body.
molecule adsorption on polar and 
-plane surfaces of GaNSumiya, Masatomo*; Sumita, Masato*; Asai, Yuya*; Tamura, Ryo*; Uedono, Akira*; Yoshigoe, Akitaka
Journal of Physical Chemistry C, 124(46), p.25282 - 25290, 2020/11
Times Cited Count：12 Percentile：47.44(Chemistry, Physical)The initial oxidation of different GaN surfaces [the polar Ga-face (+c) and N-face (-c) and the nonpolar (10
0) ()plane] under O molecular beam irradiation was studied by real-time synchrotron radiation X-ray photoelectron spectroscopy and DFT molecular dynamics calculation. The results predict that triplet O either dissociates or chemisorbs at the bridge position on the +c-surface, while on N-terminated -c-surface the O
2 molecule only undergoes dissociative chemisorption. On the -GaN surface, although the dissociation of O is dominant, the bond length and angle were found to fluctuate from those of O molecules adsorbed on the polar surfaces. The computational model including both the surface spin and polarity of GaN is useful for understanding the interface between GaN and oxide layers in metal-oxide electronic.
Sb
uncovered by soft X-ray magnetic circular dichroismSaito, Yuji; Fujiwara, Hidenori*; Yasui, Akira*; Kadono, Toshiharu*; Sugawara, Hitoshi*; Kikuchi, Daisuke*; Sato, Hideyuki*; Suga, Shigemasa*; Yamasaki, Atsushi*; Sekiyama, Akira*; et al.
Physical Review B, 102(16), p.165152_1 - 165152_8, 2020/10
Times Cited Count：1 Percentile：4.84(Materials Science, Multidisciplinary)Nakayama, Masashi; Saiga, Atsushi; Kimura, Shun; Mochizuki, Akihito; Aoyagi, Kazuhei; Ono, Hirokazu; Miyakawa, Kazuya; Takeda, Masaki; Hayano, Akira; Matsuoka, Toshiyuki; et al.
JAEA-Research 2019-013, 276 Pages, 2020/03
JAEA-Research-2019-013.pdf:18.72MB
The Horonobe Underground Research Laboratory (URL) Project is being pursued by the Japan Atomic Energy Agency (JAEA) to enhance the reliability of relevant disposal technologies for geological disposal of High-level Radioactive Waste through investigations of the deep geological environment within the host sedimentary rock at Horonobe Town in Hokkaido, north Japan. The investigations will be conducted in three phases, namely "Phase 1: Surface based investigations", "Phase 2: Construction phase" (investigations during construction of the underground facilities) and "Phase 3: Operation phase" (research in the underground facilities). According to the research plan described in the 3rd Mid- and Long- term Plan of JAEA, "Near-field performance study", "Demonstration of repository design option", and "Verification of crustal-movement buffering capacity of sedimentary rocks" are important issues of the Horonobe URL Project, and schedule of future research and backfill plans of the project will be decided by the end of 2019 Fiscal Year. The present report summarizes the research and development activities of these 3 important issues carried out during 3rd Medium to Long-term Research Phase.
resonances in a boxOno, Akira*; Xu, J.*; Colonna, M.*; Danielewicz, P.*; Ko, C. M.*; Tsang, M. B.*; Wang, Y,-J.*; Wolter, H.*; Zhang, Y.-X.*; Chen, L.-W.*; et al.
Physical Review C, 100(4), p.044617_1 - 044617_35, 2019/10
Times Cited Count：67 Percentile：98.53(Physics, Nuclear)International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and neutrons were packed in a 20-fm-large cube to calculate the number and energies of collisions during the time evolution. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). This study showed that time step in the calculation is one of the biggest causes of the discrepancies. For example, the calculation by JQMD comprises 1-fm/c time steps, each of which is composed of transport, scattering and decay phases. Therefore a sequence of scattering, and decay followed by another scattering in 1 fm/c cannot be considered. Moreover, in JQMD particles are labeled by sequential numbers and scattering reactions are simulated by the order. Therefore scattering between low ID numbers, that between high ID numbers and that between the first (low ID) pair is overlooked in JQMD. Above indications obtained in this study must be kept in our mind for future JQMD upgrades.
Strasser, P.*; Abe, Mitsushi*; Aoki, Masaharu*; Choi, S.*; Fukao, Yoshinori*; Higashi, Yoshitaka*; Higuchi, Takashi*; Iinuma, Hiromi*; Ikedo, Yutaka*; Ishida, Katsuhiko*; et al.
EPJ Web of Conferences, 198, p.00003_1 - 00003_8, 2019/01
Times Cited Count：13 Percentile：98.52(Quantum Science & Technology)
symmetry in CeCuGe; Soft X-ray absorption and hard X-ray photoemission spectroscopyAratani, Hidekazu*; Nakatani, Yasuhiro*; Fujiwara, Hidenori*; Kawada, Moeki*; Kanai-Nakata, Yuina*; Yamagami, Kohei*; Fujioka, Shuhei*; Hamamoto, Satoru*; Kuga, Kentaro*; Kiss, Takayuki*; et al.
Physical Review B, 98(12), p.121113_1 - 121113_6, 2018/09
Times Cited Count：5 Percentile：23.50(Materials Science, Multidisciplinary)Zhang, Y.-X.*; Wang, Y,-J.*; Colonna, M.*; Danielewicz, P.*; Ono, Akira*; Tsang, M. B.*; Wolter, H.*; Xu, J.*; Chen, L.-W.*; Cozma, D.*; et al.
Physical Review C, 97(3), p.034625_1 - 034625_20, 2018/03
Times Cited Count：110 Percentile：99.02(Physics, Nuclear)International comparison of heavy-ion induced reaction models were discussed in the international conference "Transport2017" held in April 2017. Owing to their importance for safety assessment of heavy-ion accelerators and dosimetry of astronauts, various models to simulate heavy-ion induced reaction models are developed. This study is intended to clarify the difference among them to pinpoint their problems. In the comparison study, 320 protons and 320 neutrons were packed in a 20-fm-large cube to calculate the number of particle-particle collisions as well as the energies of collisions during the time evolution. In addition to the calculation, their algorithms were compared. The author contributed to this study by running calculation using JQMD (JAERI Quantum Molecular Dynamics). The results were compared with those calculated by the other 15 codes from over the world. Algorithm comparison showed that JQMD calculates collision probabilities from protons at first and collisions by neutrons are simulated later, which might be unreasonable. On the other hand, it was clarified that the calculation by JQMD agrees with those by the others. Despite the fact that some codes deviate from the average by a factor of 2, JQMD exhibited stable performance.
