Effects of the longitudinal impedances on non-adiabatic bunch manipulation at flattop of J-PARC MR

Tamura, Fumihiko; Omori, Chihiro*; Yoshii, Masahito*; Tomizawa, Masahito*; Toyama, Takeshi*; Sugiyama, Yasuyuki*; Hasegawa, Katsushi*; Kobayashi, Aine*; Okita, Hidefumi

Proceedings of 19th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.175 - 178, 2023/01

https://www.pasj.jp/web_publish/pasj2022/proceedings/PDF/FROA/FROA06.pdf

J-PARC MR delivers high intensity proton beams to the neutrino experiment. Eight bunches with high peak currents are extracted from the MR by the extraction kicker, therefore the neutrino beam has the similar structure. Intermediate Water Cherenkov Detector (IWCD) will be installed for the future experiments and the IWCD requires a time structure with low peaks. We consider bunch manipulation at flattop of the MR for reducing the peak current. It should be quickly done to avoid the significant loss of the beam power. The beam gap for the kicker rise time must be kept. We propose a non-adiabatic bunch manipulation using the multiharmonic rf voltage. The longitudinal impedance in the MR can affect the beam stability. The feasibility of the manipulation is discussed by using the longitudinal simulations.

Design and actual performance of J-PARC 3 GeV rapid cycling synchrotron for high-intensity operation

Yamamoto, Kazami; Kinsho, Michikazu; Hayashi, Naoki; Saha, P. K.; Tamura, Fumihiko; Yamamoto, Masanobu; Tani, Norio; Takayanagi, Tomohiro; Kamiya, Junichiro; Shobuda, Yoshihiro; et al.

Journal of Nuclear Science and Technology, 59(9), p.1174 - 1205, 2022/09

https://doi.org/10.1080/00223131.2022.2038301

In the Japan Proton Accelerator Research Complex, the purpose of the 3 GeV rapid cycling synchrotron (RCS) is to accelerate a 1 MW, high-intensity proton beam. To achieve beam operation at a repetition rate of 25 Hz at high intensities, the RCS was elaborately designed. After starting the RCS operation, we carefully verified the validity of its design and made certain improvements to establish a reliable operation at higher power as possible. Consequently, we demonstrated beam operation at a high power, namely, 1 MW. We then summarized the design, actual performance, and improvements of the RCS to achieve a 1 MW beam.

Document collection of the Special Committee on HTTR Heat Application Test

Aoki, Takeshi; Shimizu, Atsushi; Iigaki, Kazuhiko; Okita, Shoichiro; Hasegawa, Takeshi; Mizuta, Naoki; Sato, Hiroyuki; Sakaba, Nariaki

JAEA-Review 2022-016, 193 Pages, 2022/08

JAEA-Review-2022-016.pdf:42.06MB

Aiming to realize a massive, cost-effective and carbon-free hydrogen production technology utilizing a high temperature gas cooled reactor (HTGR), Japan Atomic Energy Agency (JAEA) is planning a HTTR heat application test producing hydrogen with High Temperature Engineering Test Reactor (HTTR) achieved 950C of the highest reactor outlet coolant temperature in the world. In the HTTR heat application test, it is required to establish its safety design realizing highly safe connection of a HTGR and a hydrogen production plant by the Nuclear Regulation Authority to obtain the permission of changes to reactor installation. However, installation of a system connecting the hydrogen production plant and a nuclear reactor, and its safety design has not been conducted so far in conventional nuclear power plant including HTTR in the world. A special committee on the HTTR heat application test, established under the HTGR Research and Development Center, considered a safety design philosophy for the HTTR heat application test based on an authorized safety design of HTTR in terms of conformity to the New Regulatory Requirements taking into account new considerable events as a result of the plant modification and connection of the hydrogen production plant. This report provides materials of the special committee such as technical reports, comments provided from committee members, response from JAEA for the comments and minutes of the committee.

Phase transition and domain formation in ferroaxial crystals

Hayashida, Takeshi*; Uemura, Yohei*; Kimura, Kenta*; Matsuoka, Satoshi*; Hagihara, Masato; Hirose, Sakyo*; Morioka, Hitoshi*; Hasegawa, Tatsuo*; Kimura, Tsuyoshi*

Physical Review Materials (Internet), 5(12), p.124409_1 - 124409_10, 2021/12

https://doi.org/10.1103/PhysRevMaterials.5.124409

Reliability of J-PARC accelerator system over the past decade

Yamamoto, Kazami; Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Hayashi, Naoki; Yamazaki, Yoshio; Naito, Fujio*; Yoshii, Masahito*; Toyama, Takeshi*

JPS Conference Proceedings (Internet), 33, p.011016_1 - 011016_7, 2021/03

https://doi.org/10.7566/JPSCP.33.011016

The Japan Proton Accelerator Research Complex (J-PARC) is a multipurpose facility for scientific experiments. The accelerator complex consists of a 400-MeV Linac, a 3-GeV Rapid-Cycling Synchrotron (RCS) and a 30-GeV Main Ring synchrotron (MR). The RCS delivers a proton beam to the neutron target and MR, and the MR delivers the beams to the neutrino target and the Hadron Experimental Facility. The first operation of the neutron experiments began in December 2008. Following this, the user operation has been continued with some accidental suspensions. These suspensions include the recovery work due to the Great East Japan Earthquake in March 2011 and the radiation leak incident at the Hadron Experimental Facility. In this report, we summarize the major causes of suspension, and the statistics of the reliability of J-PARC accelerator system is analyzed. Owing to our efforts to achieve higher reliability, the Mean Time Between Failure (MTBF) has been improved.

Study of identification method by the reaction for a scattering experiment at J-PARC

Sakao, Tamao*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Masaya; Ichikawa, Yudai; Imai, Kenichi*; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; et al.

JPS Conference Proceedings (Internet), 33, p.011133_1 - 011133_6, 2021/03

https://doi.org/10.7566/JPSCP.33.011133

Study on the baryon interaction by hypernuclear spectroscopy with the reaction

Gogami, Toshiyuki*; Fujita, Manami; Hasegawa, Shoichi; Hosomi, Kenji; Imai, Kenichi*; Ichikawa, Yudai; Nanamura, Takuya; Naruki, Megumi; Sako, Hiroyuki; Sato, Susumu; et al.

Journal of Physics; Conference Series, 1643, p.012133_1 - 012133_6, 2020/12

https://doi.org/10.1088/1742-6596/1643/1/012133

Verification of dose estimation of Auger electrons emitted from Cu-64 using a combination of FNTD measurements and Monte Carlo simulations

Kusumoto, Tamon*; Matsuya, Yusuke; Baba, Kentaro*; Ogawara, Ryo*; Akselrod, M. S.*; Harrison, J.*; Fomenko, V.*; Kai, Takeshi; Ishikawa, Masayori*; Hasegawa, Sumitaka*; et al.

Radiation Measurements, 132, p.106256_1 - 106256_4, 2020/03

https://doi.org/10.1016/j.radmeas.2020.106256

Internal radiation therapy with Cu-64 concentrates energy deposition in tumor cells by virtue of released Auger electrons with low energy. In our previous study, we have attached the solutions at the surface of Fluorescent Nuclear Track Detector (FNTD) and succeeded in measuring the absorbed doses of Auger electrons registered in FNTD. However, because there are several types of radiation emitted from the source, i.e., beta rays, positron etc., the contribution degree of Auger electron to energy concentration remain uncertain. In this study, we quantitatively analyzed the spatial dose distribution in the FNTD based on Monte Carlo simulation with PHITS and GEANT4, and evaluated high dose deposited by Auger electrons. The dose distribution calculated by the PHITS code is exactly equivalent to that by Geant4. Also, the simulations are well agreement with experimental results. If the contribution of Auger electrons is ignored, the significantly high absorbed dose proximal to the source is not properly reduced. These findings demonstrate that Auger electrons work very effectively to kill cancer cells proximal to Cu-64 source while minimizing damage effects on normal cells distal to the source.

First -ray spectroscopy of an -shell hypernucleus, F

Yang, S. B.*; Hasegawa, Shoichi; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tamura, Hirokazu*; Tanida, Kiyoshi; et al.

JPS Conference Proceedings (Internet), 26, p.023015_1 - 023015_5, 2019/11

https://doi.org/10.7566/JPSCP.26.023015

Search for excited state of hypernucleus in the J-PARC E13 experiment

Nakagawa, Manami*; Hasegawa, Shoichi; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Tamura, Hirokazu; Tanida, Kiyoshi; et al.

JPS Conference Proceedings (Internet), 26, p.023005_1 - 023005_3, 2019/11

https://doi.org/10.7566/JPSCP.26.023005