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Minehara, Eisuke; Hajima, Ryoichi; Sawamura, Masaru; Nagai, Ryoji; Nishimori, Nobuyuki; Kikuzawa, Nobuhiro; Sugimoto, Masayoshi; Yamauchi, Toshihiko; Hayakawa, Takehito; Shizuma, Toshiyuki
Proceedings of 13th Symposium on Accelerator Science and Technology, p.150 - 154, 2001/10
We need a powerful and efficient free-electron laser(FEL) for industrial uses, for examples, pharmacy, medical, defense, shipbuilding, semiconductor industry, chemical industries, environmental sciences, space-debris, power beaming and so on. In order to realize such a tunable, highly-efficient, high average power, high peak power and ultra-short pulse FEL, the JAERI FEL group and I have successfully demonstrated the efficient and powerful FEL driven by a compact, stand-alone and zero-boil-off super-conducting rf linac with an energy-recovery geometry. Our discussions on the FEL will cover market-requirements for the industrial FELs, some answers from the JAERI compact, stand-alone and zero-boil-off cryostat concept and operational experience over these 8 years, our discovery of the new, highly-efficient, high-power, and ultra-short pulse lasing mode, and the energy-recovery geometry.
Agematsu, Takashi; Kamiya, Tomihiro; Kaneko, Hirohisa; Mizuhashi, Kiyoshi; Saito, Yuichi; Chiba, Atsuya; Fukuda, Mitsuhiro; Arakawa, Kazuo
Proceedings of 13th Symposium on Accelerator Science and Technology, p.467 - 469, 2001/10
A new project aiming a breakthrough in biotechnology and materials science has been proposed at TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities of JAERI. We have started designing a K900 superconducting AVF cyclotron (K900 SCC). The beam transport line for JAERI K900 SCC has been designed preliminary for heavy ion beams with an energy of more than a hundred MeV/n. An achromatic beam transport system has been designed for high transmission efficiency of ion beams and good adjustability of magnet parameters using the computer code “TRANSPORT".
Kurashima, Satoshi; Miyawaki, Nobumasa; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Yokota, Wataru; Okumura, Susumu; Arakawa, Kazuo
Proceedings of 13th Symposium on Accelerator Science and Technology, p.232 - 234, 2001/10
no abstracts in English
Nishimori, Nobuyuki; Hajima, Ryoichi; Nagai, Ryoji; Shizuma, Toshiyuki; Sawamura, Masaru; Kikuzawa, Nobuhiro; Minehara, Eisuke
Proceedings of 13th Symposium on Accelerator Science and Technology, p.458 - 460, 2001/00
Stable and bright electron multi-bunches at 16.5 MeV with a long macro-pulse duration over 0.4 ms, which consists of 4,000 micro-bunches, have been produced at the Japan Atomic Energy Research Institute (JAERI) superconducting linac driven Free-Electron Laser (FEL) facility. The bunch charge is 0.5 nC with peak current higher than 100 A. The bright electron bunch was generated using a RF compression made in two stages in the injector system, and directly led to a quasi-CW kilowatt lasing. In this paper, we describe the bunching system and electron beam performances in JAERI-FEL.
Nishimori, Nobuyuki; Nagai, Ryoji
Proceedings of 13th Symposium on Accelerator Science and Technology, p.95 - 99, 2001/00
We have observed sustained saturation in a Free-Electron Laser (FEL) oscillator at zero detuning of an optical cavity for the first time, and confirmed that the optical pulse length at zero detuning is 250 fs FWHM at wavelength of 22 um. The optical length corresponds to three optical cycles, which is the fewest cycles ever achieved at FELs in the world. The peak FEL power reaches 0.8 GW with the single optical pulse energy of 200 uJ. The sustained lasing at zero detuning is not allowed in conventional FEL oscillator theories and the physical mechanism is under investigation.
Okumura, Susumu; Kurashima, Satoshi; Ishimoto, Takayuki*; Yokota, Wataru; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.
Proceedings of 13th Symposium on Accelerator Science and Technology, p.283 - 285, 2001/00
no abstracts in English
Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Tamura, Hiroyuki; Kurashima, Satoshi; Yokota, Wataru; Okumura, Susumu; Fukuda, Mitsuhiro; Akaiwa, Katsuhiro*; et al.
Proceedings of 13th Symposium on Accelerator Science and Technology, p.193 - 195, 2001/00
The AVF cyclotron system at JAERI Takasaki has been smoothly operated without serious troubles since the first beam extraction in March, 1991. A yearly operation time is about 3200 hours on an average for recent eight years. In last two years, we performed some improvements and developments as followings: stabilization of the cyclotron beam by addition on an exclusive cooling system, designing and investigation of the flat-top system using fifth-harmonic RF, reconstruction of the rotary shutter for radiation shielding and reinforcement of the magnetic channel and its power supply. Furthermore, the renewal of main circulation pump for cooling system, replacement of shunt resistor in the power supplies and re-alignment of the several magnets along the trunk beam transport line were also carried out.
Masuda, Shinichi; Kando, Masaki; Kotaki, Hideyuki; Hosokai, Tomonao*; Kondo, Shuji; Kanazawa, Shuhei; Yokoyama, Takashi*; Matoba, Toru; Nakajima, Kazuhisa
Proceedings of 13th Symposium on Accelerator Science and Technology, 3 Pages, 2001/00
no abstracts in English
Kotaki, Hideyuki; Kando, Masaki; Kondo, Shuji; Masuda, Shinichi; Kanazawa, Shuhei; Yokoyama, Takashi*; Matoba, Toru; Nakajima, Kazuhisa
Proceedings of 13th Symposium on Accelerator Science and Technology, 3 Pages, 2001/00
no abstracts in English
Fukuda, Mitsuhiro; Arakawa, Kazuo; Yokota, Wataru; Okumura, Susumu; Agematsu, Takashi; Kamiya, Tomihiro; Mizuhashi, Kiyoshi; Nara, Takayuki; Saito, Yuichi; Ishii, Yasuyuki; et al.
Proceedings of 13th Symposium on Accelerator Science and Technology, p.71 - 73, 2001/00
A new project bringing about a breakthrough in biotechnology and materials science has been proposed at JAERI (Japan Atomic Energy Research Institute). Heavy ion beams with energy of more than 100 MeV/n are expected to contribute to remarkable progress in breeding of plants and development of new materials. Design studies of a superconducting AVF cyclotron with a K number of 900 has been started to meet requirements for the researches. A four-sector, four-dee cyclotron is being designed to cope with acceleration of both the heavy ions and 300 MeV protons.