title: Charged particle flows in the beam extraction region of a negative ion source for NBI.
abstract: Experiments by a four-pin probe and photodetachment technique were carried out to investigate the charged particle flows in the beam extraction region of a negative hydrogen ion source for neutral beam injector. Electron and positive ion flows were obtained from the polar distribution of the probe saturation current. Negative hydrogen ion flow velocity and temperature were obtained by comparing the recovery times of the photodetachment signals at opposite probe tips. Electron and positive ions flows are dominated by crossed field drift and ambipolar diffusion. Negative hydrogen ion temperature is evaluated to be 0.12 eV.
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Geng
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tsumori
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nakano
authors.affiliation: National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kisaki
authors.affiliation: National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ikeda
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Osakabe
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nagaoka
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takeiri
authors.affiliation: National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Shibuya
authors.affiliation: SOKENDAI (The Graduate University for Advanced Studies), 322-6 Oroshi, Toki, Gifu 509-5292, Japan.
authors.forename: O
authors.initials: O
authors.lastname: Kaneko