title: Operation status of the electron cyclotron resonance ion source at Gunma University.
abstract: An ECR ion source of Gunma University Heavy Ion Medical Center, so-called KeiGM [M. Muramatsu, A. Kitagawa, Y. Sakamoto, S. Sato, Y. Sato, H. Ogawa, S. Yamada, H. Ogawa, Y. Yoshida, and A. G. Drentje, Rev. Sci. Instrum. 76, 113304 (2005)], has been operated for cancer therapy and physical/biological experiment since 2010. KeiGM produces typically 230 μA of 10 keV/u C(4+) ions from CH4 gases. The vacuum pressure is kept between 1.2 × 10(-4) and 1.7 × 10(-4) Pa so as to suppress the pulse-to-pulse current fluctuation within ±10%. The extraction electrode is cleaned every 6-8 months in order to remove deposited carbon, which increases the leak current and discharge. In order to investigate the possibility of long-term operation without such maintenances, oxygen aging for the cleaning of the extraction electrode has been tested in the test bench. The same-designed ion sources at National Institute of Radiological Sciences and SAGA Heavy Ion Medical Accelerator in Tosu (SAGA-HIMAT) are also operated with stable C(4+) current, which are suitable for the continuous operation for cancer therapy.
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-0044, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Souda
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-0044, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Gunma University Heavy Ion Medical Center, Maebashi, Gunma 371-0044, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kanai
authors.affiliation: Kanagawa Cancer Center, Yokohama 241-8515, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Takeshita
authors.affiliation: National Institute of Radiological Sciences, Chiba 263-8555, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Muramatsu
authors.affiliation: National Institute of Radiological Sciences, Chiba 263-8555, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kitagawa
authors.affiliation: SAGA Heavy Ion Medical Accelerator in Tosu, Tosu, Saga 841-0071, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kanazawa
authors.affiliation: Accelerator Engineering Corporation, Chiba 263-0043, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Izumiya
authors.affiliation: Accelerator Engineering Corporation, Chiba 263-0043, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kano
mesh_terms: D017357:Cyclotrons / Q000295:instrumentation*; D004583:Electrons; D014495:Universities