title: Study of plasma meniscus and beam halo in negative ion sources using three dimension in real space and three dimension in velocity space particle in cell model.
abstract: Our previous study by two dimension in real space and three dimension in velocity space-particle in cell model shows that the curvature of the plasma meniscus causes the beam halo in the negative ion sources. The negative ions extracted from the periphery of the meniscus are over-focused in the extractor due to the electrostatic lens effect, and consequently become the beam halo. The purpose of this study is to verify this mechanism with the full 3D model. It is shown that the above mechanism is essentially unchanged even in the 3D model, while the fraction of the beam halo is significantly reduced to 6%. This value reasonably agrees with the experimental result.
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Nishioka
authors.affiliation: School of Natural and Living Sciences Education, Naruto University of Education, 748 Nakashima, Takashima, Naruto-cho, Naruto-shi, Tokushima 772-8502, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Miyamoto
authors.affiliation: Toshiba, 33 Isogo-chou, Isogo-ku, Yokohama-shi, Kanagawa 235-001, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Okuda
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Goto
authors.affiliation: Graduate School of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Hatayama
authors.affiliation: Toshiba, 33 Isogo-chou, Isogo-ku, Yokohama-shi, Kanagawa 235-001, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Fukano
mesh_terms: D008962:Models, Theoretical; D009688:Nuclear Reactors / Q000295:instrumentation*; D058626:Plasma Gases
chemical_list: D058626:Plasma Gases