title: Study of radial potential fluctuations by using a gold neutral beam probe system.
abstract: A study of fluctuation is one of the main issues in fusion plasma researches. The potential and its fluctuation are measured by a gold neutral beam probe (GNBP) in the tandem mirror GAMMA10. Since there is no stable isotope ((197)Au approximately 100%), there are little measurement errors. GNBP system can measure the potential with about +/-30 V of error. The time and spatial resolutions are estimated to be about 3 micros and 5 mm, respectively. During the formation of axial confining potentials, the radial profiles of the potential and its fluctuation were successfully measured in GAMMA10. GNBP is a useful tool for the study of radial potential fluctuation directly in plasmas.
authors.affiliation: Plasma Research Center, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305-8577, Japan. mizuguchi_masanori@prc.tsukuba.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Mizuguchi
authors.forename: M
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Y
authors.initials: Y
authors.lastname: Miyata
authors.forename: S
authors.initials: S
authors.lastname: Goshu
authors.forename: M
authors.initials: M
authors.lastname: Nakada
authors.forename: Y
authors.initials: Y
authors.lastname: Oono
authors.forename: Y
authors.initials: Y
authors.lastname: Nakashima
authors.forename: T
authors.initials: T
authors.lastname: Imai