title: Influence of H- velocity on H- extraction probability from a negative ion source.
abstract: We investigate influence of H(-) initial transport direction and kinetic energy on H(-) extraction probability with three-dimensional Monte Carlo calculation. As a result, lower energy H(-) ions are strongly trapped by the electrical potential structure, so that initial condition of H(-) transport direction is cancelled by alignment of the electric field; thus, it has lower influence for H(-) extraction probability. Besides, the potential hill induced by the beam extraction voltage more effectively enhances H(-) extraction probability for the lower energy H(-) ions. The correlation between the magnitude of the local plasma potential near the extraction region and the mean velocity of H(-) ions in the region should determine the H(-) extraction probability from the ion source.
authors.affiliation: Tokushima Bunri University, Nishihama, Yamashiro-cho, Tokushima 770-8514, Japan. ymatsumoto@tokushima.bunri-u.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Matsumoto
authors.forename: M
authors.initials: M
authors.lastname: Nishiura
authors.forename: K
authors.initials: K
authors.lastname: Shinto
authors.forename: H
authors.initials: H
authors.lastname: Yamaoka
authors.forename: M
authors.initials: M
authors.lastname: Sasao
authors.forename: M
authors.initials: M
authors.lastname: Wada