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filament arc-driven multi-cusp ion source for iBNCTShibata, Takanori*; Takagi, Akira*; Ikegami, Kiyoshi*; Sugimura, Takashi*; Nammo, Kesao*; Naito, Fujio*; Kobayashi, Hitoshi*; Kurihara, Toshikazu*; Honda, Yosuke*; Sato, Masaharu*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.385 - 387, 2018/10
Kondo, Yasuhiro; Morishita, Takatoshi; Tamura, Jun; Otani, Masashi*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.421 - 424, 2018/10
A muon linac development for a new muon g-2 experiment is now going on at J-PARC. Muons from the muon beam line (H line) at the J-PARC muon science facility are once stopped in a silica-aerogel target, and room temperature muoniums are evaporated from the aerogel. They are dissociated with lasers, then accelerated up to 212 MeV using a linear accelerator. In the current reference design, a 324-MHz radio frequency quadrupole (RFQ) and an interdigital H-mode drift tube linac (IH-DTL) are used for the low beta acceleration. We propose a 1300~MHz (L band) RFQ instead of the 324~MHz RFQ and IH-DTL as an alternative to simplify the configuration of the muon linac. In this paper, the present status of the design and the measurement of a cold model of this world first L-band RFQ is described.
Nakazawa, Yuga*; Iinuma, Hiromi*; Iwata, Yoshiyuki*; Iwashita, Yoshihisa*; Otani, Masashi*; Kawamura, Naritoshi*; Kitamura, Ryo*; Kondo, Yasuhiro; Saito, Naohito; Sue, Yuki*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.904 - 908, 2018/10
We have developed an Interdigital H-mode (IH) Drift-Tube Linac (DTL) design with an Alternative Phase Focusing (APF) scheme for a muon linac, in order to measure the anomalous magnetic moment and Electric Dipole Moment (EDM) of muons at the Japan Proton Accelerator Research Complex (J-PARC). The IH-DTL accelerates muons from beta 0.08 to 0.28 at an operational frequency of 324 MHz. The output beam emittances are calculated as 0.315 
and 0.195 mm mrad in the horizontal and vertical directions, respectively, which satisfies the experimental requirement.
Meigo, Shinichiro; Takei, Hayanori; Matsuda, Hiroki; Yuri, Yosuke*; Yuyama, Takahiro*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1035 - 1039, 2018/08
no abstracts in English
Yamada, Ippei; Ogiwara, Norio*; Hikichi, Yusuke*; Kamiya, Junichiro; Kinsho, Michikazu
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.88 - 92, 2018/08
no abstracts in English
Hotchi, Hideaki; Harada, Hiroyuki
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.371 - 375, 2018/08
no abstracts in English
ion sourceOkoshi, Kiyonori; Shinto, Katsuhiro; Nammo, Kesao*; Shibata, Takanori*; Ikegami, Kiyoshi*; Takagi, Akira*; Ueno, Akira; Namekawa, Yuya*; Oguri, Hidetomo
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.889 - 892, 2018/08
In 2017-2018 campaign, three times of long-time operation more than 2,000 hours of the J-PARC rf-driven negative hydrogen (H) ion source producing H beam with the beam current of 47 mA were successfully achieved without any serious problems. At the final day of this campaign, the ion source produced an H beam with the current of 72 mA in order to demonstrate the beam current of 60 mA at the linac exit. We are also conducting an endurance test of a J-PARC-made antenna at a test bench. Approximately 1,400-hour operation with the antenna was successfully performed.
laser stripping at J-PARC 3-GeV RCSSaha, P. K.; Harada, Hiroyuki; Kinsho, Michikazu; Miura, Akihiko; Yoshimoto, Masahiro; Okabe, Kota; Suganuma, Kazuaki; Yamane, Isao*; Irie, Yoshiro*; Liu, Y.*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.806 - 810, 2018/08
Kamiya, Junichiro; Yamamoto, Kazami; Yanagibashi, Toru*; Sato, Atsushi*; Miki, Nobuharu*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.645 - 648, 2018/08
Surround of the beam injection point in the J-PARC 3 GeV Rapid Cycling Synchrotron is the area where the residual radioactive dose is higher than other areas due to the beam scattering by the charge stripping foil. However, there is very little space to install radiation shields around the vacuum chamber in the beam injection point. Furthermore, the vacuum leak has often occurred due to the heat expansion of the chamber flange due to the induced current by the nearby pulse magnet. To solve such problems for minimizing the radiation exposure of maintenance workers, the vacuum chamber rin the beam injection point was newly designed. The space for the radiation shields was created by lengthening and the changing the cross-sectional shape. The titanium alloy with high mechanical strength was used for the flange material so that the flange was able to be fastened with higher tightening torque.
Takayanagi, Tomohiro; Ueno, Tomoaki*; Horino, Koki*; Yamamoto, Kazami; Kinsho, Michikazu
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.244 - 248, 2018/08
We will present the development of super high voltage short pulse switch power supply aiming at high performance of 3 GeV synchrotron accelerator pulsed electromagnet power supply. We are developing the switch power supply using SiC-MOSFET of the next generation power semiconductor which is higher in breakdown voltage, lower loss, and higher frequency operation than the current mainstream Si power semiconductors. The SiC conversion of semiconductors enables commercialization of thyratron substitute switches and power-saving small size switching power supplies. However, products that satisfy the specification of the thyratron (80kV/4kA) adopted for the J-PARC 3 GeV-RCS kicker power supply with one module have not been developed. Therefore, it is necessary to construct a circuit in which power semiconductors are multiplexed in series and parallel. In addition, the high-speed short pulse waveform required for the kicker power supply is designed with consideration of the circuit impedance such as inductance and stray capacitance separately from the performance improvement of the power semiconductor. Therefore, a circular radially symmetric circuit was constructed in which power semiconductors were concentrically arranged and the impedance of all parallel circuits could be made equal. As a result, waveform distortion caused by the difference in circuit impedance could be suppressed. This structure is adopted in the LTD circuit and it is indispensable for the development of semiconductor new kicker power supply. In this presentation, the results of the preliminary test and the evaluating test are reported.
Hasegawa, Kazuo; Kinsho, Michikazu; Oguri, Hidetomo; Yamamoto, Kazami; Hayashi, Naoki; Yamazaki, Yoshio; Naito, Fujio*; Yoshii, Masahito*; Yamamoto, Noboru*; Koseki, Tadashi*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1317 - 1321, 2018/08
After the summer shutdown in 2017, the J-PARC restarted user operation in late October. The Materials and Life Science Experimental Facility (MLF) used a spare target and the beam power was limited to 150-200kW. The target was replaced with a new one in the summer shutdown. The beam power was for user operation gradually increased from 300 kW to 500 kW. We have successfully demonstrated 1MW 1hour operation in July 2018. The beam power for the neutrino experimental facility (NU) was 440 kW to 470 kW. The beam was delivered to the hadron experimental facility (HD) from January to February in 2018. The repetition rate of the main ring was shortened from 5.52 to 5.20 seconds, the beam power was increased from 44 to 50 kW. From March 2018, we delivered to the NU at 490 kW stably. In the fiscal year of 2017, the availabilities for the MLF, NU and HD are 93%, 89% and 66%, respectively.
Suganuma, Kazuaki; Hiroki, Fumio; Ito, Takashi; Yamazaki, Yoshio
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.309 - 311, 2018/08
It is the report to improve the problem of flow reduction in water cooling system resolved completely in summer, 2017. It is continued the phenomenon decreasing the flow (5,800 L/min) of circulating water cooling in DTL and SDTL about 3% per week. By the flow reduction, the entire operation of J-PARC and operation of the accelerator are stopped and low flow contact of flowmeter installed in cavities. The phenomenon is progressed about 9 years since we confirm it and drastic measures for it are aspired. In this report, the point of interest to solve this problem is written. Similarly, it is suggested that the point we should be careful when we use the water cooling system it is one of the utility of J-PARC accelerator. In last summer, the flow reduction is not occur completely as specification changes and replacement of the pumps. Thanks of that, the entire operation and operation of accelerator of J-PARC is operated safety.
Fujirai, Kosuke; Suganuma, Kazuaki; Yamazaki, Yoshio
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.816 - 818, 2018/08
In order to operate rotating equipment such as a cooling water pump, it is necessary to supply grease suitable for bearings of rotating equipment. The grease replenishment interval has a value recommended by the manufacturer depending on the operation time. However, an abnormal noise occurred earlier than the replenishment cycle. I thought that the current grease replenishment cycle is not suitable for maintenance and management of rotating equipment. Therefore, I tried to search for suitable grease replenishment interval using a vibration sensor installed in the cooling water pump. As a result, it was found that the replenishment interval of grease is too long according to the manufacturer recommended value and should be supplied before the vibration acceleration value increases.
Watanabe, Tamaki*; Imao, Hiroshi*; Kamigaito, Osamu*; Sakamoto, Naruhiko*; Fukunishi, Nobuhisa*; Fujimaki, Masaki*; Yamada, Kazunari*; Watanabe, Yutaka*; Koyama, Ryo*; Toyama, Takeshi*; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.49 - 54, 2018/08
no abstracts in English
Kinsho, Michikazu; Kamiya, Junichiro; Koizumi, Oji*; Nasu, Shogo*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.668 - 670, 2018/08
Crystallinity, crystalline structure and internal force of thin films were measured by Laser Raman spectroscopy for the purpose of analyzing the fracture mechanism of the charge exchange foil due to beam hitting in this study. Thin films were used four types of HBC foil, pure carbon film (C foil) formed by arc discharge method, graphene, and carbon nanotube (CNT foil). As a result of changing the laser output and measuring the Raman peak shift of each foil, the HBC foil and the C foil had large Raman peak shift change, the D-band was negative and the G-band was opposite sign with positive. On the other hand, the graphene and the CNT foil showed small change in Raman peak shift, and both D-band and G-band were negative. From these results, it was found that a large stress occurs in the HBC foil and the C foil due to the heat load by the laser which was used for Raman spectrum measurements.
Kinsho, Michikazu; Kamiya, Junichiro; Abe, Kazuhiko*; Nakamura, Tomaru*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1177 - 1179, 2018/08
Alumina ceramics vacuum Chamber which is used for the RCS in J-PARC is composed of alumina duct, titanium (Ti) flanges and Ti sleeves. Before brazing the alumina duct and the Ti sleeves, the Ti sleeves were treated with Nitric acid-Hydrofluoric acid. The purpose of this study is to clear the effect of this treatment for titanium material. It was cleared that the roughness of the titanium material after the Nitric acid-Hydrofluoric acid treatment becomes big for SEM observation. It was also measured that the thickness of oxide film on surface of the titanium material was 12.7 nm before treatment and 6.0 nm after treatment. As a result of measuring the wettability of the brazing material which was silver brazing filler metal (Ag:72%, Cu:28%) on the Ti surface and the diffusion of the Ti material into the brazing material, it became clear that the vacuum condition of the vacuum heating furnace was important for brazing between alumina ceramics and pure titanium.
Miyao, Tomoaki*; Miura, Akihiko
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1031 - 1034, 2018/08
no abstracts in English
Kitamura, Ryo*; Otani, Masashi*; Fukao, Yoshinori*; Futatsukawa, Kenta*; Kawamura, Naritoshi*; Mibe, Tsutomu*; Miyake, Yasuhiro*; Yamazaki, Takayuki*; Kondo, Yasuhiro; Hasegawa, Kazuo; et al.
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.239 - 243, 2018/08
Muon acceleration is an important technique in exploring the new frontier of physics. A new measurement of the muon dipole moments is planned in J-PARC using the muon linear accelerator. The low-energy (LE) muon source using the thin metal foil target and beam diagnostic system were developed for the world's first muon acceleration. Negative muonium ions from the thin metal foil target as the LE muon source was successfully observed. Also the beam profile of the LE positive muon was measured by the LE-dedicated beam profile monitor. The muon acceleration test using a Radio-Frequency Quadrupole linac (RFQ) is being prepared as the first step of the muon accelerator development. In this paper, the latest status of the first muon acceleration test is described.
ion beam derived from the ultraviolet lightNakazawa, Yuga*; Iinuma, Hiromi*; Otani, Masashi*; Kawamura, Naritoshi*; Kitamura, Ryo*; Kondo, Yasuhiro; Saito, Naohito; Sue, Yuki*; Mibe, Tsutomu*; Yamazaki, Takayuki*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1047 - 1050, 2018/08
A muon LINAC is under research and development for a precise measurement of muon g-2/EDM at J-PARC. We conducted an experiment of a muon RF acceleration on October and December, 2017. The surface muon beam is irradiated to a metal degrader to generate slow negative muonium. The slow muoniums are accelerated to 90 keV with an electrostatic accelerator and an RFQ. Prior to muon RF acceleration, we conducted a commissioning of the diagnostic beam line consisting of two quadrupole magnets and a bending magnet. The ultraviolet light is irradiated to an aluminum foil and forms H ion. It is accelerated with the electrostatic accelerator and can be detected as a pseudo muon beam. This system allowed us to check operation for the diagnostic beam line, which is essential task for transportation and momentum selection of the negative muonium. In this presentation, I would like to report the performance evaluation of the diagnostic beam line by H ions.
Takahashi, Hiroki; Sawabe, Yuki; Suzuki, Yasuo*; Suzuki, Takahiro*; Kawase, Masato*
Proceedings of 15th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1105 - 1108, 2018/08
J-PARC Linac and RCS Profile Monitor and etc. are devices consisting of moving parts and driving part. In these devices, in order to move the movable part to an appropriate position without damaging it, proper control of the stepping motor used for the driving part is important. Many of the control system hardware of these drive units are used since the early days of J-PARC operation, and there is concern about malfunctions due to aging. In addition, since both VME and PLC are used as controllers, it is necessary to prepare spare parts of both control equipment in maintenance and management. Besides, the control logic differs depending on the kind of controller, VME or PLC. Therefore, maintainability of both hardware and software is an important issue. Then, we decided to proceed with updating the drive unit control system which standardized control system hardware and software. In this paper, the standardization of stepping motor control system in Linac and RCS is detailed.
