title: Formation of multi-charged ion beams by focusing effect of mid-electrode on electron cyclotron resonance ion source.
abstract: We are constructing a tandem type electron cyclotron resonance ion source (ECRIS) and a beam line for extracting ion beams. The ion beam is extracted from the second stage by an accel-decel extraction system with a single-hole and the ion beam current on each electrode is measured. The total ion beam current is measured by a faraday cup downstream the extraction electrodes. We measure these currents as a function of the mid-electrode potential. We also change the gap length between electrodes and perform similar measurement. The behaviors of these currents obtained experimentally against the mid-electrode potential show qualitatively good agreement with a simple theoretical consideration including sheath potential effects. The effect of mid-electrode potential is very useful for decreasing the beam loss for enhancing ion beam current extracted from ECRIS.
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Youta
authors.initials: Y
authors.lastname: Imai
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Daiju
authors.initials: D
authors.lastname: Kimura
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kurisu
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Dai
authors.initials: D
authors.lastname: Nozaki
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yano
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Kumakura
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Fuminobu
authors.initials: F
authors.lastname: Sato
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Yushi
authors.initials: Y
authors.lastname: Kato
authors.affiliation: Division of Electrical, Electronic and Information Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565-0871, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Iida
mesh_terms: D017357:Cyclotrons / Q000295:instrumentation*; D004566:Electrodes; D004583:Electrons