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Journal Articles

Fabrication status of charge stripper foil for 3 GeV synchrotron of J-PARC

Nakanoya, Takamitsu; Yoshimoto, Masahiro; Yamazaki, Yoshio; Takeda, Osamu*; Saeki, Riuji*; Muto, Masayoshi*

Proceedings of 16th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.545 - 549, 2019/07

In the 3 GeV Rapid Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research complex (J-PARC), we adopted the carbon stripper foil for the multi-turn H- charge exchange injection. The charge exchange foil which use in RCS is fabricated by the arc discharge method with the boron doped carbon electrode. The foil fabricated this method is called HBC foil (Hybrid Boron mixed Carbon stripper foil). HBC foil had been developed at KEK. It has high durability for the beam irradiation damage. In past days, the foil fabrication process was conducted in KEK Tsukuba-site and the foil preparation process was conducted in JAEA Tokai-site. In 2017, the foil deposition apparatus has been relocated from KEK to JAEA, and we started both processes in Tokai-site. We carried out the offline beam irradiation test for the new HBC foil which fabricated in JAEA, and we confirmed that its performance is equivalent to the original HBC foil. Next we tested a new HBC foil with actual beam in RCS and we confirmed it could withstand 1 week beam irradiation. After that, we started user operation with the new HBC foil in 2018. So far we accomplished stable user operation for one year by using the new HBC foil only.

Journal Articles

Improvement of slow purging and slow pumping system on the change exchange system in the J-PARC RCS

Tobita, Norimitsu; Yoshimoto, Masahiro; Takeda, Osamu; Saeki, Riuji; Yamazaki, Yoshio; Kinsho, Michikazu; Muto, Masayoshi*

Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1350 - 1354, 2015/09

no abstracts in English

Journal Articles

Retrievement of the charge stripping foil in J-PARC RCS

Tobita, Norimitsu; Yoshimoto, Masahiro; Yamazaki, Yoshio; Saeki, Riuji; Okabe, Kota; Kinsho, Michikazu; Takeda, Osamu*; Muto, Masayoshi*

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.915 - 919, 2014/06

The charge conversion foil used with a J-PARC 3GeV synchrotron (RCS: Rapid Cycling Synchrotron) is a thin film made from carbon about 1 micrometer thick, and it radioactivates it by continuing being irradiated with a beam. Moreover, generally it is thought that degradation progresses and foil itself breaks easily. However, when dealing with the foil after irradiation, the measure against the danger of the contamination and the contamination in the living body by foil dispersing is one of the subjects. So, in RCS, the foil exchange booth for collecting the radioactivated foil safely and certainly was installed. Even when dispersing foil temporarily, the radioactivated foil can be shut up only in Booth and a worker's contamination and contamination of work area could be prevented. Moreover, when it sees from a viewpoint of the performance gain of foil, analysis and observation of the collected foil are one of the important issues. Then, in order to observe the radioactivated foil after beam irradiation, the transparent protective case which can be sealed with a foil frame simple substance was developed. In this announcement, the equipment developed in order to collect the charge conversion foil after beam irradiation, and the established technique are announced in detail.

Journal Articles

Preperation of the charge stripping foil in J-PARC RCS

Saeki, Riuji; Yoshimoto, Masahiro; Yamazaki, Yoshio; Tobita, Norimitsu; Okabe, Kota; Kinsho, Michikazu; Takeda, Osamu*; Muto, Masayoshi*

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.523 - 526, 2014/06

RCS has loaded with the foil of 15 sheets including a reserve into equipment so that it can exchange in a short time, when foil is damaged also in a beam operating period. It is difficult for foil to be made of a thin film about 1 micrometer thick, and to treat as it is. Then, foil is fixed to the frame which stuck the SiC fiber, and foil is not touched, but only a frame is held, and it enabled it to operate it. The following preparations are needed as new foil exchange work. (1) Exfoliation and recovery of foil which have been vapor-deposited to glass substrate. (2) Dryness and logging of exfoliative foil. (3) Preparation of SiC wire, and attachment on frame. (4) Fix foil to a frame. (5) Although charge on a magazine-rack was performed manually altogether until now, there were many work man days, and the quality of the prepared foil had variation. Then, equipment required in order to secure reproducibility was developed. The technique for working efficiently simultaneously was established. In this announcement, the technique established until now and the developed jigs are announced in detail.

Journal Articles

Present status of klystron power supply systems for J-PARC linac 2013

Kawamura, Masato*; Chishiro, Etsuji; Hori, Toshihiko; Shinozaki, Shinichi; Sato, Fumiaki; Fukui, Yuji*; Futatsukawa, Kenta*; Yamazaki, Masayoshi*; Sagawa, Ryu*; Miyajima, Noriyuki*; et al.

Proceedings of 10th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.605 - 607, 2014/06

This report describes the present status of the klystron power supply systems for the J-PARC linac. The systems for the 181 MeV linac were operated from September to May. A few breakdowns were occurred, and are described in this report. The new systems for the upgrade of the linac from 181MeV to 400 MeV have been installed until now, and the 3 HVDCPSs and the 3 anode modulators of the new systems have been operated. All the systems for 400 MeV linac will be operated in this autumn.

Journal Articles

High power RF test station for RFQII at J-PARC linac

Hori, Toshihiko; Chishiro, Etsuji; Shinozaki, Shinichi; Sato, Fumiaki; Morishita, Takatoshi; Kondo, Yasuhiro; Futatsukawa, Kenta*; Fukui, Yuji*; Kawamura, Masato*; Sugimura, Takashi*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1240 - 1242, 2013/08

no abstracts in English

Journal Articles

Status of J-PARC linac LLRF after the Tohoku Earthquake

Futatsukawa, Kenta*; Anami, Shozo*; Kobayashi, Tetsuya*; Fang, Z.*; Fukui, Yuji*; Michizono, Shinichiro*; Kawamura, Masato*; Sato, Fumiaki; Shinozaki, Shinichi; Chishiro, Etsuji; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.769 - 773, 2013/08

no abstracts in English

Journal Articles

RF control system for the RFQ test station at J-PARC linac

Fukui, Yuji*; Kawamura, Masato*; Kobayashi, Tetsuya*; Fang, Z.*; Futatsukawa, Kenta*; Sato, Fumiaki; Shinozaki, Shinichi; Suzuki, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.762 - 764, 2013/08

no abstracts in English

Journal Articles

Present status of klystron power supply systems for J-PARC linac 2012; Recovery from Earthquake Disaster, HVDCPS breakdown and energy upgrade

Kawamura, Masato*; Chishiro, Etsuji; Hori, Toshihiko; Shinozaki, Shinichi; Sato, Fumiaki; Fukui, Yuji*; Futatsukawa, Kenta*; Yamazaki, Masayoshi*; Sagawa, Ryu*; Yukitake, Mitsuteru*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.1243 - 1247, 2013/08

no abstracts in English

Journal Articles

Beam loss reduction by the beam duct realignment in the J-PARC linac beam transport line

Tamura, Jun; Ao, Hiroyuki; Asano, Hiroyuki; Ikegami, Masanori*; Maruta, Tomofumi; Miura, Akihiko; Morishita, Takatoshi; Oguri, Hidetomo; Ouchi, Nobuo; Sawabe, Yuki*; et al.

Proceedings of 9th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.377 - 380, 2013/08

In the J-PARC linac, almost all the cavities and magnets have been precisely aligned because the accelerator tunnel has been deformed by the 2011 Tohoku Earthquake. In the beam transport line called MEBT2 and A0BT at the downstream of the drift tube linac, the beam duct has been roughly aligned after the precise alignment of the quadruple doublets. During the first beam operation after the earthquake, remarkable beam loss and residual radiation have been recognized at the MEBT2 and A0BT. As the result of the duct position measurement, the misalignement including over 10 mm shift from the beam axis was found. By conducting the beam duct realignment, the beam loss and the residual radiation were successfully decreased. In this paper, the procedure of the beam duct alignment and the beam loss due to the misalignment are described.

Journal Articles

Present status of RF source in J-PARC linac; Recovery from earthquake disaster and energy upgrade

Kawamura, Masato*; Chishiro, Etsuji; Shinozaki, Shinichi; Fang, Z.*; Fukui, Yuji*; Naito, Fujio*; Yamazaki, Masayoshi*; Tsubota, Naoaki; Futatsukawa, Kenta; Sato, Fumiaki; et al.

Proceedings of 8th Annual Meeting of Particle Accelerator Society of Japan (Internet), 3 Pages, 2011/08

We will report about status of linac 400 MeV upgrade program and northeast Japan earthquake restoration. On March 11, the linac suffered serious damage as consequence of the earthquake, and was shuttled down for long term. Linac RF group restores the facilities and is accomplishing 400 MeV upgrade at the same time.

Journal Articles

Power supply system for klystron in J-PARC linac

Kawamura, Masato*; Fukui, Yuji*; Naito, Fujio*; Chishiro, Etsuji; Yamazaki, Masayoshi*; Suzuki, Hiroyuki*; Shinozaki, Shinichi; Hasegawa, Kazuo

Proceedings of 25th International Linear Accelerator Conference (LINAC 2010) (CD-ROM), p.887 - 889, 2010/09

This paper describes the present status, technical specifications, operating experience, and upgrade plane for the power supply system (PS system) for the klystrons in the J-PARC. The PS systems include both the high voltage DC power supplies (DCPSs), which drives one or four modulating-anode klystron each, and the anode-modulators, one per klystron. Currently, the energy output of the J-PARC linac is 181 MeV, which includes the energy necessary to run twenty 324 MHz klystrons. In 2012, the linac will add twenty-five 972 MHz klystrons and upgrade the energy output to 400 MeV.

Journal Articles

Influence of heat treatment on long term creep properties of 9Cr-W-Mo-V-Nb steel

Obara, Satoshi; Wakai, Takashi; Asayama, Tai; Yamada, Yoshiyuki*; Nakazawa, Takanori*; Yamazaki, Masayoshi*; Hongo, Hiromichi*

Tetsu To Hagane, 96(4), p.172 - 181, 2010/04

This paper describes the effect of heat treatment on mechanical properties of 9Cr-W-Mo-V-Nb steel as a part of development of high Cr steel for fast breeder reactor (FBR). The effects of normalizing temperature and tempering temperature and time on creep properties were investigated from the viewpoint of microstructures. Creep strength increased with increase in normalizing temperature from 950$$^{circ}$$C to 1200$$^{circ}$$C. The microstructural factors that improve creep strength are increased amount of MX which precipitated during tempering process and increased dislocation density. In addition, coarsening of prior austenite grain size also contribute to increasing creep strength. Although creep rupture time of 780$$^{circ}$$C-1h tempering specimen was greater than that of 700$$^{circ}$$C-1h and 750$$^{circ}$$C-1h tempering specimen in a long-term region exceeding 20000h at 650$$^{circ}$$C, creep ductility and reduction of area of the former remarkably degraded compared to those of the latter.

Journal Articles

Operating experience of the J-PARC linac

Hasegawa, Kazuo; Asano, Hiroyuki; Chishiro, Etsuji; Hori, Toshihiko; Ito, Takashi; Kobayashi, Tetsuya; Kondo, Yasuhiro; Namekawa, Yuya; Oguri, Hidetomo; Okoshi, Kiyonori; et al.

Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.55 - 57, 2009/00

The beam commissioning of the J-PARC linac started in November 2006 and 181 MeV acceleration was successfully achieved in January 2007. The linac has delivered beams to the 3 GeV Rapid Cycling Synchrotron for its commissioning, and then, the subsequent Main Ring Synchrotron and the neutron target commissioning. The linac uses a Cs-free LaB$$_{6}$$-driven ion source and 20 units of 324 MHz klystrons. As of June 2008, the operation times are about 3,000 and 6,000 hours for the ion source and the RF source, respectively. The operating experience of the linac is described.

Journal Articles

High power test of 972 MHz waveguide systems for J-PARC Linac

Hori, Toshihiko; Yamazaki, Masayoshi; Yamaguchi, Seiya*; Hasegawa, Kazuo; Linac RF Group

NIFS-MEMO-55, p.289 - 292, 2008/03

no abstracts in English

Journal Articles

Present status of RF source operation at J-PARC linac

Yamazaki, Masayoshi; Chishiro, Etsuji; Kobayashi, Tetsuya; Hori, Toshihiko; Suzuki, Hiroyuki; Anami, Shozo*; Kawamura, Masato*; Fukui, Yuji*; Nammo, Kesao*; Fang, Z.*; et al.

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.485 - 487, 2008/00

no abstracts in English

Journal Articles

High power test of the first ACS module for the J-PARC linac

Hirano, Koichiro; Ao, Hiroyuki; Morishita, Takatoshi; Asano, Hiroyuki; Hori, Toshihiko; Yamazaki, Masayoshi; Kobayashi, Tetsuya; Kubota, Chikashi*; Yamazaki, Yoshishige

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.497 - 499, 2008/00

An ACS (Annular Coupled Structure) module has been developing for the 190-MeV to 400-MeV part of the J-PARC Linac. We have conducted the high power test of the first ACS module which consists of two accelerating tanks with 17 cells and a bridge tank with 9 cells. This paper describes results of the high power RF tests. The module achieved an average axial accelerating gradient of E0 = 4.5 MV/m at 1.8 MW RF input power, 0.6 ms pulse width, and 50 Hz repetition rate.

Journal Articles

DATA collection using memory area of PLC touch panel for J-PARC linac RF

Suzuki, Hiroyuki; Chishiro, Etsuji; Kobayashi, Tetsuya; Hori, Toshihiko; Yamazaki, Masayoshi; Anami, Shozo*; Yamaguchi, Seiya*; Kawamura, Masato*; Fukui, Yuji*; Fang, Z.*

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.467 - 469, 2008/00

no abstracts in English

Journal Articles

Present status of the 972 MHz RF test stand for J-PARC 2008

Hori, Toshihiko; Yamazaki, Masayoshi; Chishiro, Etsuji; Suzuki, Hiroyuki; Ao, Hiroyuki; Hirano, Koichiro; Hasegawa, Kazuo; Yamaguchi, Seiya*

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.482 - 484, 2008/00

no abstracts in English

Journal Articles

Performance of J-PARC linac RF system

Kobayashi, Tetsuya; Chishiro, Etsuji; Hori, Toshihiko; Suzuki, Hiroyuki; Yamazaki, Masayoshi; Anami, Shozo*; Fang, Z.*; Fukui, Yuji*; Kawamura, Masato*; Michizono, Shinichiro*; et al.

Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.2128 - 2130, 2007/08

High power operation of all the RF systems of J-PARC linac was started for the cavity conditioning in October 2006. Twenty 324-MHz klystrons have supplied the power to the accelerating cavities successfully, and the beam commissioning was started in November 2006. The RF drive and control systems are working well, and required stability is satisfied.

48 (Records 1-20 displayed on this page)