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Nakamura, Yoshiteru; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Kurashima, Satoshi; Fukuda, Mitsuhiro; Okumura, Susumu; Yokota, Wataru; Yoshida, Kenichi; Miyawaki, Nobumasa; et al.
Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004), p.157 - 159, 2005/00
The AVF cyclotron system at JAERI Takasaki has been smoothly operated for 13 years since 1991. This system continues to deliver various ion species with very frequent alterations of operational conditions. In order to provide a heavy ion beam with energy spread of 0.02 % required for microbeam production, we have developed a flat-top acceleration system, an additional buncher driven by saw-tooth wave, and improved the central region of the cyclotron. An old gradient corrector of passive type was replaced by a new gradient corrector with an active coil inside to obtain complete matching between the trunk beam line and extraction trajectory from the cyclotron. A compact ion source with a set of movable permanent magnet was designed to produce mainly light ions, which will be replaced the existing multi-cusp ion source in future.
Miyawaki, Nobumasa; Kurashima, Satoshi; Okumura, Susumu; Chiba, Atsuya; Agematsu, Takashi; Kamiya, Tomihiro; Kaneko, Hirohisa; Nara, Takayuki; Saito, Yuichi; Ishii, Yasuyuki; et al.
Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004), p.208 - 210, 2005/00
A project to expand at TIARA (Takasaki Ion Accelerators for Advanced Radiation Application) facilities of JAERI has been proposed to broaden applications in biotechnology and materials science. Heavy ions with energy more than 100 MeV/n are required for remarkable progress in breeding of plant and development of new materials. The magnet of a superconducting AVF cyclotron with a K number of 900 has been designed to cope with acceleration of both 150 MeV/n heavy ions and 300 MeV protons. The lower limit of energies has been investigated to overlap the energy region covered by the JAERI AVF cyclotron, required to increase beam time for present users. We have designed a beam transport system to satisfy requirements of the applications.
Kurashima, Satoshi; Fukuda, Mitsuhiro; Miyawaki, Nobumasa; Okumura, Susumu; Yoshida, Kenichi; Nara, Takayuki; Agematsu, Takashi; Ishibori, Ikuo; Arakawa, Kazuo; Nakamura, Yoshiteru
Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004), p.362 - 364, 2005/00
A flat-top (FT) acceleration system for the JAERI AVF cyclotron has been designed to achieve the energy spread of dE/E = 0.02 % mainly for a microbeam production. The FT acceleration using fundamental and fifth-harmonic frequencies for an acceleration voltage is an excellent technique to reduce the energy spread. The FT waveform was successfully observed at the dee voltage pick-up in a power test at a fundamental frequency of 17.475 MHz. We succeeded in accelerating 260 MeV Ne ions at a fundamental frequency of 17.475 MHz by superimposing the fifth-harmonic voltage on the fundamental one. In the preliminary beam development, single turn extraction has been achieved by the FT acceleration mode.
Okumura, Susumu; Miyawaki, Nobumasa; Kurashima, Satoshi; Yoshida, Kenichi; Fukuda, Mitsuhiro; Ishibori, Ikuo; Agematsu, Takashi; Nara, Takayuki; Nakamura, Yoshiteru; Arakawa, Kazuo
Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004), p.410 - 412, 2005/00
A simple analyzing system has been developed to measure the energy spread of the beam extracted from the JAERI AVF cyclotron with an energy resolution of dE/E = 0.001%. The high analyzing power can be obtained with an existing deflecting magnet system in the transport line by installing three sets of slits with a minimum width of 0.01 mm and a beam intensity monitor with a Faraday cup and semiconductor detectors. These new instruments have been compactly designed to fulfill the geometrical condition of the existing beam diagnostic chambers, which are located at the object and image positions. Installation of the analyzing system was completed and a preliminary test has been carried out. This system will be used for optimization of the flat-top acceleration system to achieve the energy spread of dE/E = 0.02%, required for microbeam production.
Watanabe, Masao; Chiba, Yoshiaki*; Koseki, Tadashi*; Katayama, Takeshi*; Oshiro, Yukimitsu*; Watanabe, Shinichi*
Proceedings of 17th International Conference on Cyclotrons and Their Applications (CYCLOTRONS 2004) (CD-ROM), 3 Pages, 2005/00
A broad-band rf cavity as a buncher of ion beams has been developed. Operating frequencies of the cavity is between 18 and 45 MHz. The cavity was installed in the beam transport line of the Hi-ECR ion source system in CNS for the beam test. Beam structure of 30 MHz was successfully observed for 10 keV proton beam.