title: Behavior of moving plasma in solenoidal magnetic field in a laser ion source.
abstract: In a laser ion source, a solenoidal magnetic field is useful to guide the plasma and to control the extracted beam current. However, the behavior of the plasma drifting in the magnetic field has not been well understood. Therefore, to investigate the behavior, we measured the plasma ion current and the total charge within a single pulse in the solenoid by changing the distance from the entrance of the solenoid to a detector. We observed that the decrease of the total charge along the distance became smaller as the magnetic field became larger and then the charge became almost constant with a certain magnetic flux density. The results indicate that the transverse spreading speed of the plasma decreased with increasing the field and the plasma was confined transversely with the magnetic flux density. We found that the reason of the confinement was not magnetization of ions but an influence induced by electrons.
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Ikeda
authors.affiliation: Department of Electrical Engineering, Nagaoka University of Technology, Nagaoka, Niigata 940-2137, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Collider-Accelerator Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
authors.forename: M
authors.initials: M
authors.lastname: Okamura
authors.affiliation: Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Kanagawa 226-8502, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Horioka