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Miura, Akihiko; Sako, Hiroyuki; Akikawa, Hisashi*; Ikegami, Masanori*
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.1008 - 1010, 2010/05
A wire scanner monitor (WSM) is one of essential measurement devices for beam commissioning of current accelerators. J-PARC Linac employs a number of WSMs for transverse beam profile. The transverse matching is performed based on the measured beam width. In addition, we have tried to measure halo component with the WSMs. In this paper, we describe the experimental results obtained in a beam study to characterize the operational performance of the WSMs.
Sako, Hiroyuki; Ueno, Akira; Okawa, Tomohiro*; Kondo, Yasuhiro; Morishita, Takatoshi; Ikegami, Masanori*; Akikawa, Hisashi*
Proceedings of 24th International Linear Accelerator Conference (LINAC 2008) (CD-ROM), p.260 - 262, 2009/00
In designed very high intensity proton beam of J-PARC LINAC, precise control of transverse beam dynamics is extremely important for suppression of beam loss. We present results of transverse beam matching and orbit corrections. Excellent matching performance has been achieved with mismatch factor less than 5% at beam current of 5 to 30 mA. Orbit deviations were suppressed within 1mm in horizontal and vertical directions in the whole LINAC.
Sato, Susumu; Igarashi, Zenei*; Tomisawa, Tetsuo; Miura, Akihiko; Ueno, Akira; Sako, Hiroyuki; Morishita, Takatoshi; Kondo, Yasuhiro; Shen, G.; Akikawa, Hisashi*; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.500 - 502, 2008/00
no abstracts in English
Akikawa, Hisashi*; Igarashi, Zenei*; Ikegami, Masanori*; Lee, S.*; Sato, Susumu; Shen, G.; Tomisawa, Tetsuo; Ueno, Akira
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.1472 - 1474, 2007/08
Beam commissioning of J-PARC linac has been performed since November 2006. We have wire scanners in order to measure beam profile and perform transverse matching. Four wire scanners are installed at each matching section. We report the result of measurement of beam profile and matching.
Sato, Susumu; Tomisawa, Tetsuo; Sako, Hiroyuki; Shen, G.; Ueno, Akira; Akikawa, Hisashi*; Igarashi, Zenei*; Lee, S.*; Ikegami, Masanori*; Kamikubota, Norihiko*
Proceedings of 2007 Particle Accelerator Conference (PAC '07) (Internet), p.4072 - 4074, 2007/08
The beam commissioning of J-PARC LINAC has been started in November 2006. Beam Position Monitors (BPM's) which had been calibrated on the bench setup with a scanning wire, take beam-based-calibration method in order to enable the beam to pass at the centre of a quadrupole magnet (Q-magnet). The installed BPM's and their calibration methods are described.
Ikegami, Masanori*; Lee, S.*; Akikawa, Hisashi*; Igarashi, Zenei*; Kondo, Yasuhiro; Okawa, Tomohiro; Ueno, Akira; Sako, Hiroyuki; Ao, Hiroyuki; Sato, Susumu; et al.
KEK Proceedings 2006-15 (CD-ROM), p.347 - 349, 2007/03
We plan to start the beam commissioning of J-PARC linac with reduced energy of 181 MeV in the end of this year. Detailed commissioning strategies for the linac and the succeeding beam transport line, to which we refer as L3BT or Linac-to-3-GeV-synchrotron Beam Transport, will be presented in this talk. The emphasis will be put on the commissioning procedures for two debuncher cavities and a transverse collimator system located in L3BT, because they are key elements in determining the final beam quality at the injection point to the succeeding 3-GeV synchrotron. The unique design and features of the collimator system are also presented.
Sato, Susumu; Tomisawa, Tetsuo; Kondo, Yasuhiro; Ueno, Akira; Akikawa, Hisashi*; Igarashi, Zenei*; Lee, S.*; Kubota, Chikashi*; Ikegami, Masanori*
Proceedings of 23rd International Linear Accelerator Conference (LINAC 2006) (CD-ROM), p.268 - 270, 2007/00
In the J-PARC LINAC, upgrade of beam diagnostics of LEBT and MEBT is taken. Three beam current monitors and two beam phase monitors are added. In the LEBT and MEBT section, large number of accelerator devices are placed. Therefore to save the space, several modifications are needed, for example, additional monitors need to be welded with each other. Those details of the upgrade of beam diagnostics system are described.
Sako, Hiroyuki; Shen, G.; Ueno, Akira; Okawa, Tomohiro; Akikawa, Hisashi*; Ikegami, Masanori*
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.598 - 600, 2007/00
Transverse matching has been performed at J-PARC LINAC for matching sections at DTL-SDTL, S01A-S03B, MEBT2-ACS, and L3BT. Each matching section consists of 4 wire scanners and upstream 4 quadrupole magnets. From r.m.s. of beam profiles measured at 4 wire scanners, transverse Twiss parameters and emittance are fitted with Newton method based on an online model. Field of quadrupole magnets with matching conditions is calculated based on the model. At beam current of 5 mA and 25 mA, matching factors of within 4% were achieved.
Sato, Susumu; Tomisawa, Tetsuo; Ao, Hiroyuki; Ueno, Akira; Akikawa, Hisashi*; Igarashi, Zenei*; Lee, S.*
Proceedings of 10th European Particle Accelerator Conference (EPAC 2006) (CD-ROM), p.1151 - 1153, 2006/00
In the LINAC section of J-PARC, we have several type of sensors of monitor, i.e, Beam Position Monitor, Beam Profile Monitor, Beam Size Monitor, Current Monitor, Beam Phase Monitor, Beam Loss Monitor. Those sensors are being installed currently. The procedures, remarks during the installation, status are described in this paper. As an examle, the beam postion monitors are one of sensors which are taken cared intensively for their positioning on their housing quadrupole magnet, then our cares during their installation are described.
Sato, Susumu; Igarashi, Zenei*; Akikawa, Hisashi*; Tomisawa, Tetsuo; Lee, S.*; Ueno, Akira; Ikegami, Masanori*; Ao, Hiroyuki
Proceedings of 3rd Annual Meeting of Particle Accelerator Society of Japan and 31st Linear Accelerator Meeting in Japan (CD-ROM), p.127 - 129, 2006/00
In J-PARC LINAC section, several types of beam position monitors (BPMs) from 37.7 mm to 120 mm in diameter are allocated. In this paper, background of design and key points for a larger diameter (180 mm) of BPM are reported.
Sato, Susumu; Tomisawa, Tetsuo; Akikawa, Hisashi; Ueno, Akira; Lee, S.*; Igarashi, Zenei*; Ikegami, Masanori*; Toyama, Takeshi*; Kamikubota, Norihiko*
Proceedings of 2005 Particle Accelerator Conference (PAC '05) (CD-ROM), p.2777 - 2779, 2005/00
The J-PARC LINAC requires for fine control of beam position to minimize beam loss. So that BPMs need to be calibrated with the accuracy of about a hundred micro-meters. The accuracy of BPMs are calibrated with the calibration tool and real beam. In this paper, details of these developments around BPMs are to be reported.
beam with Nd:YAG laser in J-PARCTomisawa, Tetsuo; Akikawa, Hisashi; Sato, Susumu; Ueno, Akira; Kondo, Yasuhiro; Oigawa, Hiroyuki; Sasa, Toshinobu; Hasegawa, Kazuo; Lee, S.*; Igarashi, Zenei*; et al.
Proceedings of 7th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators (DIPAC 2005), p.275 - 277, 2005/00
The photo neutralization method with Nd:YAG laser for negative hydrogen ions has been expected as an available candidate for the transverse beam profile measurement. The fraction of photo detached electron can also be used for charge exchange procedure to extract very low power proton beam for Transmutation Experimental Facility in J-PARC. The laser system has advantages of maintenance and radiation hardness in high intensity proton accelerators. In order to establish the low power beam extraction system and beam profile monitor, the photo neutralization efficiency must be surveyed in practical beam line with high intensity H beam. In this paper, an experimental set-up and preliminary results of photo neutralization method for intense H beam in J-PARC MEBT1 are described.
Kondo, Yasuhiro; Akikawa, Hisashi; Anami, Shozo*; Asano, Hiroyuki*; Fukui, Yuji*; Igarashi, Zenei*; Ikegami, Kiyoshi*; Ikegami, Masanori*; Ito, Takashi; Kawamura, Masato*; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.156 - 158, 2004/08
A commissioning of the J-PARC linac DTL1 is now under way at KEK. A 30mA H beam was accelerated to 19.7-MeV, and 100% transmission was obtained with a 20-msec-pulse-width and 12.5-Hz-repetition beam. In this paper, present status of the DTL1 commissioning and preliminary results of the commissioning, such as emittance measurements, are presented.
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
1 W/m at the linac). To achieve the requirement, beam trajectory needs to be controlled with accuracy of some 100 
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.
Ao, Hiroyuki; Akikawa, Hisashi; Ueno, Akira; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*; Noguchi, Shuichi*; Hayashizaki, Noriyosu*; Paramonov, V.*
Proceedings of 22nd International Linear Accelerator Conference (LINAC 2004), p.75 - 77, 2004/00
The J-PARC (Japan Proton Accelerator Research Complex) LINAC will be commissioned with energy of 181-MeV using 50-keV ion source, 3-MeV RFQ, 50-MeV DTL and 181-MeV SDTL (Separated DTL) on September 2006. It is planed to be upgraded by using a 400-MeV ACS (Annular Coupled Structure), which is a high-beta structure most suitable for the J-PARC, in a few years from the commissioning. The first ACS type cavity, which will be used as the first buncher between the SDTL and the ACS, is under fabrication. Detailed design and tuning procedure of ACS cavities has been studied with RF simulation analysis and cold-model measurements. The results of cold-model measurements, fabrication status, and related development items are described in this paper.
Akikawa, Hisashi; Ao, Hiroyuki; Hayashizaki, Noriyosu*
Proceedings of 28th Linear Accelerator Meeting in Japan, p.242 - 243, 2003/08
no abstracts in English
Hayashizaki, Noriyosu*; Ao, Hiroyuki; Akikawa, Hisashi; Hasegawa, Kazuo; Yamazaki, Yoshishige; Ikegami, Masanori*
Proceedings of 28th Linear Accelerator Meeting in Japan, p.75 - 77, 2003/08
no abstracts in English
Ao, Hiroyuki; Akikawa, Hisashi
Proceedings of 28th Linear Accelerator Meeting in Japan, p.239 - 241, 2003/08
This paper shows the design and development status of the bridge coupler for the ACS (Annular Coupled Structure) in the J-PARC Linac. The half-scale models were fabricated, and RF measurement results are compared with numerical analysis.
Ao, Hiroyuki; Akikawa, Hisashi; Hayashizaki, Noriyosu*
Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.365 - 367, 2003/00
The first J-PARC ACS cavity is under fabrication. Aluminum and OFC test cells were fabricated and tested for RF properties. This paper discusses the RF measurement setup, comparing the measurements and analyses, and the outlook for the next step.
