title: Time evolution of negative ion profile in a large cesiated negative ion source applicable to fusion reactors.
abstract: To understand the physics of the cesium (Cs) recycling in the large Cs-seeded negative ion sources relevant to ITER and JT-60SA with ion extraction area of 45-60 cm × 110-120 cm, the time evolution of the negative ion profile was precisely measured in JT-60SA where the ion extraction area is longitudinally segmented into 5. The Cs was seeded from the oven at 180 °C to the ion source. After 1 g of Cs input, surface production of the negative ions appeared only in the central segment where a Cs nozzle was located. Up to 2 g of Cs, the negative ion profile was longitudinally expanded over full ion extraction area. The measured time evolution of the negative ion profile has the similar tendency of distribution of the Cs atoms that is calculated. From the results, it is suggested that Cs atom distribution is correlated with the formation of the negative ion profile.
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hanada
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kojima
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kashiwagi
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Umeda
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Hiratsuka
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Ichikawa
authors.affiliation: Japan Atomic Energy Agency, 801-1, Mukoyama, Naka 311-0193, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Watanabe
authors.affiliation: Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA.
authors.forename: L
authors.initials: L
authors.lastname: R Grisham
authors.affiliation: National Institute for Fusion Science, Toki, Gifu 509-5792, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Tsumori
authors.affiliation: National Institute for Fusion Science, Toki, Gifu 509-5792, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kisaki