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Journal Articles

Beam position monitor system of J-PARC RCS

Hayashi, Naoki; Kawase, Masato; Hatakeyama, Shuichiro; Hiroki, Seiji; Saeki, Riuji; Takahashi, Hiroki; Teruyama, Yuzo*; Toyokawa, Ryoji*; Arakawa, Dai*; Hiramatsu, Shigenori*; et al.

Nuclear Instruments and Methods in Physics Research A, 677, p.94 - 106, 2012/06

 Times Cited Count:12 Percentile:66.54(Instruments & Instrumentation)

A beam position monitor (BPM) system at J-PARC RCS is described. The J-PARC RCS is a rapid-cycling proton synchrotron and its designed beam power is 1 MW. A diameter of the BPM detector is larger than 250 mm, however the system has to measure the beam position very accurately. The system should work not only for the high intensity but also for lower intensity. There are 54 BPM around the ring and most of them are placed inside steering magnets because of quite limited space. The BPM detector is an electro static type and it has four electrodes, and a pair of electrode gives a good linear response with diagonal cut shape to detect the charge center precisely. The signal processing unit, which is equipped with 14-bit 40 MSPS ADC and 600 MHz DSP, has been developed. They are controlled via shared memory space and EPICS. It is capable to record full 25 Hz pulse data for averaged mode and it could also store whole waveform data for further analysis, like turn-by-turn position calculation.

Journal Articles

Multi-wire profile monitor for J-PARC 3GeV RCS

Hiroki, Seiji; Hayashi, Naoki; Kawase, Masato; Noda, Fumiaki; Saha, P. K.; Sako, Hiroyuki; Takahashi, Hiroki; Ueno, Akira; Arakida, Yoshio*; Lee, S.*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.1131 - 1133, 2008/06

A set of six multi-wire profile monitors (MWPMs) has been installed in the injection area of the RCS (Rapid-Cycling Synchrotron), and contributed to the initial commissioning for establishing an optimum injection orbit. The Au coated W wires (0.1 mm dia.) for the H$$^{-}$$ beam are fixed to a ceramic wind frame for two directions (horizontal and vertical with 17.7 deg. tilt, typically 51 wires with 2.9 mm or 9.5 mm distance), and the frame can be scanned for horizontal or vertical direction by using a stepping-motor driven actuator. A combination of the 17.7 deg. tilt wires and the precise scan function provides two step measurements, i.e. a rough profile is obtained only at one shot, and a detailed profile is measured for typically 101 shots (10 mm scan at 0.1 mm interval) thereafter. The beam induced charge signals are amplified, integrated and held by using a signal processing circuit. The signals are sequentially retrieved through multiplexers and digitized for obtaining a beam profile.

Journal Articles

Beam instrumentations for the J-PARC RCS commissioning

Hayashi, Naoki; Hiroki, Seiji; Saeki, Riuji; Toyokawa, Ryoji; Yamamoto, Kazami; Yoshimoto, Masahiro; Arakawa, Dai*; Hiramatsu, Shigenori*; Lee, S.*; Sato, Kenichiro*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.1125 - 1127, 2008/06

A 3-GeV Rapid-Cycling Synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC) has been commissioned recently. During its beam commissioning, various beam diagnostic instrumentation has been used. The multi-wire profile monitor (MWPM) is used to establish injection and H0 dump line. The electron catcher confirms that the beam hits a charge exchange carbon foil and the specified current monitor limits the beam current to the H0 dump. Single pass BPMs and ionization profile monitors (IPM) help to check the one pass orbit without circulation of the beam. The beam position monitor (BPM) can measure both COD and turn-by-turn position. Tune monitor system consists of exciter and its own BPM. The exciter shakes the beam and coherent oscillation. Dedicated BPMs, Fast CT (FCT) and Wall Current Monitor (WCM) are used for RF feedback or feedfoward control. It will describe the performance of each instruments and how they are contributed to the successful beam commissioning.

Journal Articles

The Beam position monitor system for the J-PARC RCS

Hayashi, Naoki; Hiroki, Seiji; Saeki, Riuji; Toyokawa, Ryoji*; Yamamoto, Kazami; Arakawa, Dai*; Hiramatsu, Shigenori*; Lee, S.*; Sato, Kenichiro*; Tejima, Masaki*; et al.

Proceedings of 11th European Particle Accelerator Conference (EPAC '08) (CD-ROM), p.1128 - 1130, 2008/06

The Beam Position Monitor (BPM) system of the J-PARC RCS has been fabricated, installed and operated successfully during the beam commissioning. There are 54 BPMs around the ring and most of them are placed inside steering magnets. The BPM is electro static type and it has four electrodes. A pair of electrode gives a linear response with diagonal cut shape and they were calibrated before their installation. The signal processing unit, which is equipped with 14-bit 14MSPS ADC and 600MHz DSP, has been developed for the system. In order to measure small signal, especially during the initial phase of the commissioning, careful design also done for cabling. The paper presents the current performance of the system.

Journal Articles

The Status of the J-PARC RCS beam monitor system

Hayashi, Naoki; Hiroki, Seiji; Saha, P. K.; Saeki, Riuji; Toyokawa, Ryoji*; Yamamoto, Kazami; Yoshimoto, Masahiro; Arakawa, Dai*; Hiramatsu, Shigenori*; Lee, S.*; et al.

Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.243 - 245, 2008/00

The J-PARC RCS has been beam commissioned since fall 2007. During such a short period, the following items have been established. Establishment of the injection orbit, beam circulation, acceleration up to 3GeV, optics parameters measurements and it achieved 50 kW beam power (4$$times$$10$$^{12}$$ ppb). The beam monitor system has an important role for smooth beam commissioning. This paper describes the status of the beam monitor system, BPM, Injection monitors, IPM, current monitor, tune meter and BLM of the RCS.

Journal Articles

The Beam diagnostics system for J-PARC synchrotrons

Hayashi, Naoki; Hiroki, Seiji; Sato, Kenichiro; Toyokawa, Ryoji; Arakawa, Dai*; Lee, S.*; Hashimoto, Yoshinori*; Miura, Takako*; Toyama, Takeshi*

KEK Proceedings 2006-15 (CD-ROM), p.128 - 130, 2007/03

The beam diagnostics system for J-PARC synchrotrons (RCS and MR) will be presented. The design of the system will be described for high current machines. Some test results will be reported.

Journal Articles

Injection and dump line monitor system of J-PARC RCS

Sato, Kenichiro; Hiroki, Seiji; Lee, S.*; Hayashi, Naoki; Yamamoto, Kazami; Hiramatsu, Shigenori*; Toyama, Takeshi*; Arakawa, Dai*; Igarashi, Zenei*; Saeki, Riuji

Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.297 - 299, 2007/00

At the injection and H0 dump line of J-PARC RCS, different beam monitors have been installed. Main purpose of the beam monitors in the injection line is to generate a beam position and profile to adjust the injection trajectory to the RCS ring. To guide the injected beam precisely is, needless to say, required to reduce the beam loss in the ring. Hence the monitor system is one of the most essential to operate the RCS. At the injection point, there are also some beams that are not match the RCS ring, that is negative and neutral proton beam. H0 dump accepts the unsuitable beams through the H0 dump line. The power limitation of the H0 dump is 4 kW. The monitor system in the dump line is to handle the beam and to monitor the dumped beam power. At the conference these monitor systems will be outlined.

Journal Articles

Development of the beam diagnostics system for the J-PARC rapid-cycling synchrotron

Hayashi, Naoki; Hiroki, Seiji; Kishiro, Junichi*; Teruyama, Yuzo*; Toyokawa, Ryoji; Arakawa, Dai*; Lee, S.*; Miura, Takako*; Toyama, Takeshi*

Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.299 - 301, 2005/00

Development of the beam diagnostics system for the J-PARC (Japan Proton Accelerator Research Complex) Rapid-Cycling Synchrotron is described. The system consists of Beam Position Monitor (BPM), Beam Loss Monitor (BLM), Current monitors (DCCT, SCT, MCT, FCT, WCM), Tune meter system, 324MHz-BPM, Profile monitor, and Halo monitor. BPM electrode is electro-static type and its electronics is designed for both COD and turn-by-turn measurements. Five current monitors have different time constants in order to cover wide frequency range. The tune meter is consisted of RFKO and the beam pick-up electrode. For the continuous injected beam monitoring, 324MHz-BPM detects Linac frequency. Two types of profile monitor are multi-wire for low intensity tuning and the residual gas monitor for non-destructive measurement.

Journal Articles

Design of 4-stripline beam position monitors of the J-PARC linac SDTL

Tomisawa, Tetsuo; Kishiro, Junichi; Hiroki, Fumio; Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Nigorikawa, Kazuyuki*; Toyama, Takeshi*

Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.165 - 167, 2004/08

It proceeds with the beam monitor production of the beam diagnosis system with J-PARC. In this paper, the present status of beam position monitors (BPM) for the SDTL is described. The impedance of strip line monitor have been adjusted in the construction of housing and electrodes of the BPM. The 4-stripline BPM has already been examined in the medium energy beam transport (MEBT) line. Preliminary results of beam position measurement for various beam conditions are reported.

Journal Articles

Systematic calibration of beam position monitor at J-PARC LINAC

Sato, Susumu; Tomisawa, Tetsuo; Hiroki, Fumio; Lee, S.*; Igarashi, Zenei*; Ikegami, Masanori*; Ueno, Akira; Kondo, Yasuhiro; Hasegawa, Kazuo; Toyama, Takeshi*; et al.

Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.467 - 469, 2004/08

As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction. For this accelerator, it is required to minimize the beam loss (typically, lower than0.1$$sim$$1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 $$mu$$m. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 stripline pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.

Journal Articles

Systematic calibration of beam position monitor in the high intensity proton accelerator (J-PARC) linac

Sato, Susumu; Igarashi, Zenei*; Lee, S.*; Tomisawa, Tetsuo; Hiroki, Fumio; Kishiro, Junichi; Ikegami, Masanori*; Kondo, Yasuhiro; Hasegawa, Kazuo; Ueno, Akira; et al.

Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.429 - 431, 2004/00

As a joint project of KEK and JAERI, a MW class of high intensity proton accelerator (J-PARC), consisting of Linac, 3 GeV-RCS, 50 GeV-MR, is under construction at Tokai, Japan. For this accelerator, it is required to minimize the beam loss (typically, lower than 0.1$$sim$$1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 micro-meter. The first stage of the acceleration (up to 181 MeV during the first stage of construction) is done by linac. The beam position monitor (BPM) in the linac utilizes 4 strip-line pickups (50 ohm) on the beam transportation chamber. In this paper, systematic calibration of the BPM is described.

Journal Articles

Beam monitor for J-PARC linac accelerator

Tomisawa, Tetsuo; Kishiro, Junichi; Igarashi, Zenei*; Lee, S.*; Hiroki, Fumio

Proceedings of 28th Linear Accelerator Meeting in Japan, p.428 - 430, 2003/08

It is an important factor whether to have a beam loss held how, and the part of the beam diagnosis is important with the accurate beam transport, the occurrence of the high quality beam to accelerate a high intensity proton beam to handle with J-PARC linac accelerator safely. It responds to the purpose, and the beam monitor used for this beam diagnosis has it variously. There are an electric current monitor, a phase monitor, a beam position monitor, a profile monitor, a beam size monitor, a screen monitor, a beam loss monitor, and so on. Report it about these beam monitors in the present condition.

Journal Articles

ITER fuelling, pumping, wall conditioning systems and fuel dynamics analysis

Nakamura, Hiroo; Ladd, P.*; Federici, G.*; Janeschitz, G.*; Schaubel, K. M.*; Sugihara, Masayoshi; Busigin, A.*; Gierszewski, P.*; Hiroki, Seiji; Hurztmeirer, H. S.*; et al.

Fusion Engineering and Design, 39-40, p.883 - 891, 1998/09

 Times Cited Count:5 Percentile:44.27(Nuclear Science & Technology)

no abstracts in English

Journal Articles

Measurement of secondary electron emission coefficient of wall materials using auger electron spectromter

Hiroki, S.; ; ; Murakami, Yoshio

Shinku, 30(1), p.14 - 21, 1987/01

no abstracts in English

Journal Articles

JT-60 divertor pumping system and its initial operation in ohmically heated divertor discharges

Ando, T.; Nakamura, H.; Yoshida, H.; Sunaoshi, H.; Arai, T.; Akino, N.; Hiroki, S.; Yamamoto, Masahiro; Okubo, Minoru; Shimizu, M.*; et al.

Proc. 14th Symp. on Fusion Technology, 1986, Vol.1, p.615 - 620, 1987/00

no abstracts in English

JAEA Reports

Surface Analysis and Secondary Electron Rate of Cu Plating for Vacuum Wave Guide of LHRF Coupler in JT-60

; ; Hiroki, S.; ; ; Saigusa, Mikio; *; ; ; ; et al.

JAERI-M 85-131, 28 Pages, 1985/08

JAERI-M-85-131.pdf:1.07MB

no abstracts in English

JAEA Reports

Measurement of Secondary Electron Emission Coefficient of Wall Materials Using Auger Electron Spectroscopy

Hiroki, S.; ; *; ; Murakami, Yoshio

JAERI-M 85-123, 23 Pages, 1985/08

JAERI-M-85-123.pdf:0.71MB

no abstracts in English

Journal Articles

Development of TiC-coated wall materials for JT-60

; Murakami, Yoshio; ; Hiroki, S.; ; *; *; *

Journal of Nuclear Materials, 133-134, p.754 - 759, 1985/00

 Times Cited Count:16 Percentile:85.3(Materials Science, Multidisciplinary)

no abstracts in English

Journal Articles

Surface cleaning test with RF

Hiroki, S.; *; ; ; ; Murakami, Yoshio

Shinku, 28(5), p.300 - 303, 1985/00

no abstracts in English

JAEA Reports

Performanse Test of Twisted-Wired Titanium Evaporat for In-Situ TiC Deposition

*; ; Hiroki, S.; ; Murakami, Yoshio

JAERI-M 84-105, 51 Pages, 1984/06

JAERI-M-84-105.pdf:2.81MB

no abstracts in English

27 (Records 1-20 displayed on this page)