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Kondo, Yasuhiro; Kitamura, Ryo; Fuwa, Yasuhiro; Morishita, Takatoshi; Moriya, Katsuhiro; Takayanagi, Tomohiro; Otani, Masashi*; Cicek, E.*; Ego, Hiroyasu*; Fukao, Yoshinori*; et al.
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.636 - 641, 2022/09
The muon linac project for the precise measurement of the muon anomalous magnetic and electric dipole moments, which is currently one of the hottest issues of the elementary particle physics, is in progress at J-PARC. The muons from the J-PARC muon facility are once cooled to room temperature, then accelerated up to 212 MeV with a normalized emittance of 1.5 
mm mrad and a momentum spread of 0.1%. Four types of accelerating structures are adopted to obtain the efficient acceleration with a wide beta range from 0.01 to 0.94. The project is moving into the construction phase. We already demonstrated the re-acceleration scheme of the decelerated muons using a 324-MHz RFQ in 2017. The high-power test of the 324-MHz Interdigital H-mode (IH) DTL using a prototype cavity was performed in 2021. The fabrication of the first module of 14 modules of the 1296-MHz Disk and Washer (DAW) CCL will be done to confirm the production process. Moreover, the final design of the travelling wave accelerating structure for the high beta region is also proceeding. In this paper, the recent progress toward the realization of the world first muon linac will be presented.
Sue, Yuki*; Yotsuzuka, Mai*; Futatsukawa, Kenta*; Hasegawa, Kazuo; Iijima, Toru*; Iinuma, Hiromi*; Inami, Kenji*; Ishida, Katsuhiko*; Kawamura, Naritoshi*; Kitamura, Ryo; et al.
Physical Review Accelerators and Beams (Internet), 23(2), p.022804_1 - 022804_7, 2020/02
Times Cited Count：2 Percentile：20.86(Physics, Nuclear)A destructive monitor to measure the longitudinal bunch width of a low-energy and low-intensity muon beam was developed. This bunch-width monitor (BWM) employed microchannel plates to detect a single muon with high time resolution. In addition, constant-fraction discriminators were adopted to suppress the time-walk effect. The time resolution was measured to be 65 ps in rms using a picosecond-pulsed laser. This resolution satisfied the requirements of the muon linac of the J-PARC E34 experiment. We measured the bunch width of negative-muonium ions accelerated with a radio-frequency quadrupole using the BWM. The bunch width was successfully measured to be 
54 
11 ns, which is consistent with the simulation.
Sue, Yuki*; Iijima, Toru*; Inami, Kenji*; Yotsuzuka, Mai*; Iinuma, Hiromi*; Nakazawa, Yuga*; Otani, Masashi*; Kawamura, Naritoshi*; Shimomura, Koichiro*; Futatsukawa, Kenta*; et al.
Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.55 - 60, 2019/07
The result of bunch size measurement of muon accelerated by RFQ up to 89 keV is presented in this paper. A four-stage muon linac for precise measurement of muon property is under construction in the J-PARC. The demonstration of the first muon RF acceleration with an RFQ linac was conducted and the transverse profile of the accelerated muons was measured in 2017. As one of the remaining issues for the beam diagnostic system, the longitudinal beam profile after the RFQ should be measured to match the profile to the designed acceptance of the subsequent accelerator. For this purpose, the new longitudinal beam monitor using the microchannel plate is under development. The time resolution of the monitor aims to be around 30 to 40 ps corresponding to 1% of a period of an operating frequency of the accelerator, which is 324 MHz. On November 2018, the bunch size of accelerated negative muonium ion of 89 keV with the RFQ was measured using this monitor at the J-PARC MLF. The measured bunch width is 
ns, which is consistent with the simulation.
Shirato, Nobuaki*; Matsui, Hiroya; Morioka, Hiroshi; Hatanaka, Koichiro; Takeuchi, Ryuji; Hatakeyama, Nobuya; Ohara, Hidefumi; Nakajima, Takahiro; Kunitomo, Takahiro
JNC TN5440 2005-001, 412 Pages, 2005/06
JNC-TN5440-2005-001.pdf:20.87MB
We held Horonobe technical review meeting 4 times a year. The first meeting is for the plan of Horonobe underground research laboratory and others. The secound meeting is for geology of Horonobe area and modeling study and data acquisition for safety assessment methodology and others. The third meeting is for ventilation network analyses on URL plan. The fourth meeting is for the remote monitoring system using ACROSS. This report is records of these meetings.
Takeuchi, Koichiro*; Akiyama, Masatsugu*; Hirao, Toshio
Proceedings of the 6th International Workshop on Radiation Effects on Semiconductor Devices for Space Application (RASEDA-6), p.195 - 199, 2004/10
no abstracts in English
Ida, Mizuho*; Nakamura, Hideo; Nakamura, Hiroshi*; Nakamura, Hiroo; Ezato, Koichiro; Takeuchi, Hiroshi
Fusion Engineering and Design, 63-64, p.333 - 342, 2002/12
Times Cited Count：43 Percentile：90.88(Nuclear Science & Technology)no abstracts in English
Ida, Mizuho*; Horiike, Hiroshi*; Akiba, Masato; Ezato, Koichiro; Iida, Toshiyuki*; Inoue, Shoji*; Miyamoto, Seiji*; Muroga, Takeo*; Nakamura, Hideo; Nakamura, Hiroshi*; et al.
Journal of Nuclear Materials, 307-311(Part2), p.1686 - 1690, 2002/12
Times Cited Count：6 Percentile：38.82(Materials Science, Multidisciplinary)no abstracts in English
