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Miyawaki, Nobumasa; Okumura, Susumu; Kurashima, Satoshi; Kashiwagi, Hirotsugu; Yoshida, Kenichi; Yuri, Yosuke; Yuyama, Takahiro; Ishibori, Ikuo; Agematsu, Takashi; Ishizaka, Tomohisa; et al.
Proceedings of 4th Annual Meeting of Particle Accelerator Society of Japan and 32nd Linear Accelerator Meeting in Japan (CD-ROM), p.604 - 606, 2007/00
The main probe of the JAEA AVF cyclotron has been modified to measure a beam phase width in the accelerating region without extracting the beam from the cyclotron, which could cause the beam loss at the extraction device. The main probe consists of a carbon block for a beam current measurement and a plastic scintillator for a beam phase measurement. A correlation between the beam phase width and the position of phase slits was confirmed.
Okumura, Susumu; Arakawa, Kazuo; Fukuda, Mitsuhiro; Nakamura, Yoshiteru; Yokota, Wataru; Ishimoto, Takayuki*; Kurashima, Satoshi; Ishibori, Ikuo; Nara, Takayuki; Agematsu, Takashi; et al.
Review of Scientific Instruments, 76(3), p.033301_1 - 033301_6, 2005/03
Times Cited Count：9 Percentile：42.25(Instruments & Instrumentation)A magnetic field drift, gradual decrease of the order of 10
in several tens of hours, was observed with the beam intensity decrease in an operation of an azimuthally-varying-field (AVF) cyclotron. From our experimental results, we show that the temperature increase of the magnet iron by the heat transfer from the excitation coils can induce such change of the magnetic field as to deteriorate the beam quality. The temperature control of the magnet iron was realized by thermal isolation between the main coil and the yoke and by precise control of the cooling water temperature of the trim coils attached to the pole surfaces in order to prevent temperature change of the magnet iron. The magnetic field stability of 
5
10
and the beam intensity stability of 2% have been achieved by this temperature control.
Fukuda, Mitsuhiro; Okumura, Susumu; Kurashima, Satoshi; Miyawaki, Nobumasa; Ishii, Yasuyuki; Saito, Yuichi; Mizuhashi, Kiyoshi; Agematsu, Takashi; Chiba, Atsuya; Sakai, Takuro; et al.
Proceedings of 1st Annual Meeting of Particle Accelerator Society of Japan and 29th Linear Accelerator Meeting in Japan, p.643 - 645, 2004/08
A superconducting AVF cyclotron with a bending limit of 900 MeV and a focusing limit of 300 MeV is being designed to meet the requirements for the research in materials science and biotechnology at TIARA facility of JAERI. The spiral-sector shape of the cyclotron magnet has been optimized for acceleration of a 300 MeV proton to produce sufficient focusing forces in an extraction region. An energy range of the superconducting AVF cyclotron overlaps with that of the present K110 JAERI AVF cyclotron. Characteristics of a resonator for the superconducting AVF cyclotron have been investigated using the MAFIA code. An acceleration voltage in a frequency range of 24 to 64 MHz can be produced by the resonator with a 
/2 excitation mode.
Fukuda, Mitsuhiro; Okumura, Susumu; Ishii, Yasuyuki; Saito, Yuichi; Miyawaki, Nobumasa; Mizuhashi, Kiyoshi; Agematsu, Takashi; Kurashima, Satoshi; Chiba, Atsuya; Sakai, Takuro; et al.
Dai-14-Kai Kasokuki Kagaku Kenkyu Happyokai Hokokushu, p.302 - 304, 2003/00
no abstracts in English
