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Yokota, Wataru; Nara, Takayuki; Ishibori, Ikuo; Kurashima, Satoshi; Yoshida, Kenichi; Yuyama, Takahiro; Ishizaka, Tomohisa; Agematsu, Takashi; Uno, Sadanori; Chiba, Atsuya; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.22 - 24, 2008/08
no abstracts in English
Yuri, Yosuke; Ishizaka, Tomohisa; Yuyama, Takahiro; Okumura, Susumu; Ishibori, Ikuo
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.397 - 399, 2008/00
no abstracts in English
Sugimoto, Hiroshi*; Okamoto, Hiromi*; Wei, J.*; Yuri, Yosuke; Sessler, A. M.*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.436 - 438, 2008/00
no abstracts in English
Shinto, Katsuhiro; Vermare, C.*; Harami, Taikan*; Sugimoto, Masayoshi; Garin, P.*; Maebara, Sunao; Sakaki, Hironao; Ohira, Shigeru; Okumura, Yoshikazu; Mosnier, A.*; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.255 - 258, 2008/00
Hasegawa, Katsushi; Hara, Keigo*; Nomura, Masahiro; Omori, Chihiro*; Schnase, A.; Tamura, Fumihiko; Toda, Makoto*; Yamamoto, Masanobu; Yoshii, Masahito*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.394 - 396, 2008/00
The RF cavity using Magnetic Alloy (MA) cores has been developed for achieving the high field gradient in J-PARC synchrotron. Because of adopting the quality factor of 26, cut core configuration has been used in Main Ring RF cavities. Electromagnetic simulations of HOM analysis about RF cavity of MA cores, cut core configuration and between the cut core gap were performed. In this paper, a simulation method of MA core and results of HOM analysis for cut core and MA core are presented.
Ueno, Tomoaki; Takayanagi, Tomohiro; Kinsho, Michikazu; Yoshimoto, Masahiro; Kamiya, Junichiro; Watanabe, Masao
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.355 - 357, 2008/00
The injection bump power supply of J-PARC 3GeV RCS is composed of the assemblies that are multiple connection with IGBT choppers, and It can make optionally current wave form. But the high-frequency noise due to the switching of the IGBT choppers has caused the damages to the control system and the monitor system. So the ground wires that connect to each power supply panel and each magnet has been changed to copper sheets. As a result, the noise decreases rapidly and it kept balance controllable.
Kikuzawa, Nobuhiro; Hajima, Ryoichi; Hayakawa, Takehito; Shizuma, Toshiyuki; Toyokawa, Hiroyuki*; Ogaki, Hideaki*; Minehara, Eisuke
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.598 - 600, 2008/00
Laser-Compton-backscattered photons from an energy-recovery linac (ERL) and a high power laser realize a high-efficiency, high-flux and tunable monochromatic 
-ray source. A nondestructive assay method by using the monoenegetic -rays and nuclear resonance fluorescence (NRF) make possible to isotope imaging. The purpose of our work is to demonstrate of the NRF-based isotope imaging system. For this evaluation, we are developing a GEANT4-based Monte Carlo simulation code. In the simulation, we assume metal cubes (4
44 mm) of U238 and lead are contained in a concrete block of 5 cm thickness. The simulation results indicate that the nondestructive spectrometric method can be applicable in the isotope imaging.
Nagai, Ryoji; Sawamura, Masaru; Hajima, Ryoichi; Nishimori, Nobuyuki; Kikuzawa, Nobuhiro; Iijima, Hokuto
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.601 - 603, 2008/00
no abstracts in English
Nishimori, Nobuyuki; Nagai, Ryoji; Iijima, Hokuto; Hajima, Ryoichi; Sawamura, Masaru; Honda, Yosuke*; Muto, Toshiya*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.595 - 597, 2008/00
no abstracts in English
Schnase, A.; Ezura, Eiji*; Hara, Keigo*; Hasegawa, Katsushi; Nomura, Masahiro; Omori, Chihiro*; Shimada, Taihei; Suzuki, Hiromitsu; Takagi, Akira*; Tamura, Fumihiko; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.340 - 342, 2008/00
Hikichi, Yusuke; Ogiwara, Norio
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.343 - 345, 2008/00
no abstracts in English
Mio, Keigo; Ogiwara, Norio; Hikichi, Yusuke; Marushita, Motoharu*; Arai, Hideyuki*; Goto, Keiichi*; Nishizawa, Daiji*; Furukori, Hisayoshi*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.252 - 254, 2008/00
-Ray irradiation tests of vacuum system equipment were carried out to evaluate radiation resistance for J-PARC 3GeV RCS(Rapid-Cycling Synchrotron). Intense of radiation fields will be expected since large intensity proton beam current of RCS. Regarding Steady operation and radiation protection, radiation hardness is required approximately 10MGy to 100MGy. Cable, Feed-through-connector, Cooling-fan, Baking heater, piping Sealants have been tested. All the examination objects were evaluated to have radiation hardness at least 10MGy and expected to operate with stability under radiation field of 3GeV RCS.
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 (410
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.
Tamura, Fumihiko; Schnase, A.; Nomura, Masahiro; Yamamoto, Masanobu; Suzuki, Hiromitsu; Shimada, Taihei; Hasegawa, Katsushi; Yoshii, Masahito*; Omori, Chihiro*; Toda, Makoto*; et al.
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.337 - 339, 2008/00
The beam commissioning of the J-PARC RCS was started in October 2007 and acceleration of 
protons has been successfully achieved in February 2008. Also, the beam commissioning of MR began in May 2008. The RF capture of the beam and the extraction at the injection energy of 3 GeV was successfully performed. In both of the RCS and MR, MA (magnetic alloy) cavities are employed to achieve high accelerating voltages which are necessary to accelerate the high intensity proton beams. We employ full-digital LLRF control systems to realize precise and reproducible control of RF frequencies, voltages and phases. We present the status of the RF acceleration with examples of the beam signals. Also we discuss the future plans.
Suganuma, Kazuaki; Hikichi, Yusuke; Ogiwara, Norio; Sukenobu, Satoru*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.346 - 348, 2008/00
Pure Ti is adopted as a material for ducts and bellows at the proton accelerator 3 GeV-RCS in J-PARC project, because of its small residual radioactivity. We intended to apply vacuum firing to reduce the hydrogen content in the Ti. The firing at temperatures higher than 550
C was effective in reducing the hydrogen content in the Ti. At the same time, we have measured the mechanical properties because grain growth leads to decrease in mechanical strength. Even after treatment at 750C for 8 hr, the decreases in tensile and yield strength were so small (
10%) that we have no anxiety about the reduction of mechanical strength. Based on the above results, to reduce the hydrogen content, the Ti bellows and ducts for the RCS have been vacuum fired at 650C for 8 hr and at 750C for 8 hr, respectively.
Kanazawa, Kenichiro; Ogiwara, Norio; Suganuma, Kazuaki; Inohara, Takashi*; Wada, Kaoru*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.391 - 393, 2008/00
no abstracts in English
Ao, Hiroyuki; Hirano, Koichiro; Morishita, Takatoshi; Asano, Hiroyuki; Naito, Fujio*; Ueno, Akira; Ikegami, Masanori*; Hasegawa, Kazuo; Yamazaki, Yoshishige; Paramonov, V.*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.494 - 496, 2008/00
The J-PARC ACS cavity consists of many cell parts. For the mass production, the ACS requires about 1300 cell parts, so that it is important to reduce the machining time. In the previous ACS model, it took about three hours per one coupling slot. We, therefore, optimized the slot design, the tolerance, and the machining process. As a result, the machining time reduced to forty-five minutes per one slot. The four test cells were fabricated to measure the frequencies and Q-values, and these results were compared with the electromagnetic analysis with the Microwave Studio. Between the analysis and the measurement, the differences are 11.5 MHz and 45 MHz, respectively, for the accelerating mode, and for the coupling mode.
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
Iijima, Hokuto; Nagai, Ryoji; Nishimori, Nobuyuki; Hajima, Ryoichi
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.604 - 606, 2008/00
We report an experimental result of measuring a mid-infrared FEL optical pulse by means of frequency-resolved optical gating (FROG) and a comparison with a numerical simulation result. The measurement was performed at JAEA ERL-FEL with the perfect synchronism condition. The FEL optical pulse was measured to be 0.6 ps of the pulse duration and 4.6 THz of the bandwidth. The simulation results were 0.5 ps and 4.4 THz, respectively. The measurement result was good agreement with the simulation result within a measurement error. The chirp in frequency domain followed a cubic function. This behavior is the so-called "self-chirp", which is not caused by a dispersive material but relation of electron-bunch parameters and FEL-undulator parameters.
Hajima, Ryoichi; Nagai, Ryoji; Iijima, Hokuto; Nishimori, Nobuyuki; Honda, Yosuke*; Muto, Toshiya*
Proceedings of 5th Annual Meeting of Particle Accelerator Society of Japan and 33rd Linear Accelerator Meeting in Japan (CD-ROM), p.607 - 609, 2008/00
We review R&D status of the high-brightness electron gun for future ERL light sources.