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Miyazawa, Yu*; Ikegami, Masashi*; Miyasaka, Tsutomu*; Oshima, Takeshi; Imaizumi, Mitsuru*; Hirose, Kazuyuki*
Proceedings of 42nd IEEE Photovoltaic Specialists Conference (PVSC-42) (CD-ROM), p.1178 - 1181, 2015/06
Gejo, Tatsuo*; Ikegami, Takeshi*; Homma, Kenji*; Harries, J.; Tamenori, Yusuke*
Journal of Physics B; Atomic, Molecular and Optical Physics, 46(7), p.075102_1 - 075102_9, 2013/04
Times Cited Count：3 Percentile：18.98(Optics)Miura, Akihiko; Sato, Susumu; Tomisawa, Tetsuo; Igarashi, Zenei*; Miyao, Tomoaki*; Ikegami, Masanori*; Toyama, Takeshi*
Proceedings of 10th European Workshop on Beam Diagnostics and Instrumentation for Particle Accelerators (DIPAC 2011) (Internet), p.50 - 52, 2011/08
J-PARC had developed the beam diagnostic devices for the present J-PARC linac and has used them since the operation start. J-PARC linac began the energy upgrade project since 2009 and 21 ACS cavities will be installed. Because the beam parameters are updated due to the project, new beam diagnostic devices are additionally fabricated and the diagnostic devices at the downstream part where the beam energy will be increased up to 400 MeV by ACS cavities should be developed. In this paper, we introduce the development of the beam diagnostic devices for the project and the new developing devices.
Shobuda, Yoshihiro; Chin, Y. H.*; Toyama, Takeshi*; Ikegami, Masanori*
Proceedings of 2009 Particle Accelerator Conference (PAC '09) (DVD-ROM), p.4701 - 4703, 2009/05
The kicker magnet is one of dominant sources of impedances with 3 GeV RCS at J-PARC. It has been considered that this impedance gives us the significant constraint to increase the beam intensity. Recently, the 300 kW beam was accomplished at 3 GeV RCS, while no instability is found. We discuss the space charge effect to stabilize the beam instability.
Nishiuchi, Mamiko; Daito, Izuru; Ikegami, Masahiro; Daido, Hiroyuki; Mori, Michiaki; Orimo, Satoshi; Ogura, Koichi; Sagisaka, Akito; Yogo, Akifumi; Pirozhkov, A. S.; et al.
Applied Physics Letters, 94(6), p.061107_1 - 061107_3, 2009/02
Times Cited Count：59 Percentile：87.41(Physics, Applied)A pair of conventional permanent magnet quadrupoles is used to focus a 2.4 MeV laser-driven proton beam at a 1 Hz repetition rate. The magnetic field strengths are 55 T/m and 60 T/m for the first and second quadrupoles respectively. The proton beam is focused to a spot size (full width at half maximum) of 2.7
8 mm
at a distance of 650 mm from the source. This result is in good agreement with a Monte Carlo particle trajectory simulation.
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
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.
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.
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 0.11 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.
Matsukado, Koji*; Esirkepov, T. Z.; Kinoshita, Kenichi*; Daido, Hiroyuki; Utsumi, Takayuki*; Li, Z.*; Fukumi, Atsushi*; Hayashi, Yukio; Orimo, Satoshi; Nishiuchi, Mamiko; et al.
Physical Review Letters, 91(21), p.215001_1 - 215001_4, 2003/11
Times Cited Count：136 Percentile：95.24(Physics, Multidisciplinary)no abstracts in English
Kunitomi, Kazuhiko; Takeda, Takeshi; Shinozaki, Masayuki; Okubo, Minoru; *; Koikegami, Hajime*
Nihon Genshiryoku Gakkai-Shi, 37(4), p.316 - 326, 1995/00
Times Cited Count：1 Percentile：17.52(Nuclear Science & Technology)no abstracts in English
