title: High current DC negative ion source for cyclotron.
abstract: A filament driven multi-cusp negative ion source has been developed for proton cyclotrons in medical applications. In Cs-free operation, continuous H(-) beam of 10 mA and D(-) beam of 3.3 mA were obtained stably at an arc-discharge power of 3 kW and 2.4 kW, respectively. In Cs-seeded operation, H(-) beam current reached 22 mA at a lower arc power of 2.6 kW with less co-extracted electron current. The optimum gas flow rate, which gives the highest H(-) current, was 15 sccm in the Cs-free operation, while it decreased to 4 sccm in the Cs-seeded operation. The relationship between H(-) production and the design/operating parameters has been also investigated by a numerical study with KEIO-MARC code, which gives a reasonable explanation to the experimental results of the H(-) current dependence on the arc power.
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Etoh
authors.affiliation: Graduate School of Science and Technology, Keio University, Kanagawa 223-8522, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Onai
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Aoki
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Mitsubori
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Arakawa
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Sakuraba
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kato
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Mitsumoto
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hiasa
authors.affiliation: Sumitomo Heavy Industries, Ltd., Tokyo 141-6025, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Yajima
authors.affiliation: High Energy Accelerator Research Organization (KEK), Ibaraki 305-0801, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shibata
authors.affiliation: Graduate School of Science and Technology, Keio University, Kanagawa 223-8522, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Hatayama
authors.affiliation: Fusion Research and Development Directorate, Japan Atomic Energy Agency, Aomori 039-3212, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Okumura
mesh_terms: D000838:Anions; D002586:Cesium; D017357:Cyclotrons; D003903:Deuterium
chemical_list: D000838:Anions; D002586:Cesium; D003903:Deuterium