title: Density fluctuation measurements using beam emission spectroscopy on Heliotron J.
abstract: This paper describes the measurement of the density fluctuation using beam emission spectroscopy in Heliotron J, having the non-symmetrical helical-magnetic-axis configuration. In order to optimize the sightlines, the numerical calculations are carried out to estimate the spatial resolution and the observation location. When a tangential neutral beam is used as diagnostic one, suitable sightlines from the newly installed diagnostic port are selected whose spatial resolution Δρ is less than ± 0.07 over the entire plasma region. Modification of the interference filter and the detection systems enables us to measure the radial profile of the density fluctuation. Each of the three coherent modes due to the fast-ion-driven magnetohydrodynamic instabilities has different radial structure of the density fluctuation.
authors.affiliation: Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan. kobayashi@iae.kyoto-u.ac.jp
authors.forename: S
authors.initials: S
authors.lastname: Kobayashi
authors.forename: S
authors.initials: S
authors.lastname: Kado
authors.forename: T
authors.initials: T
authors.lastname: Oishi
authors.forename: S
authors.initials: S
authors.lastname: Ohshima
authors.forename: T
authors.initials: T
authors.lastname: Kagawa
authors.forename: Y
authors.initials: Y
authors.lastname: Nagae
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Mizuuchi
authors.forename: K
authors.initials: K
authors.lastname: Nagasaki
authors.forename: H
authors.initials: H
authors.lastname: Okada
authors.forename: T
authors.initials: T
authors.lastname: Minami
authors.forename: T
authors.initials: T
authors.lastname: Estrada
authors.forename: S
authors.initials: S
authors.lastname: Murakami
authors.forename: H Y
authors.initials: HY
authors.lastname: Lee
authors.forename: T
authors.initials: T
authors.lastname: Minami
authors.forename: T
authors.initials: T
authors.lastname: Harada
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: S
authors.initials: S
authors.lastname: Konoshima
authors.forename: K
authors.initials: K
authors.lastname: Toushi
authors.forename: F
authors.initials: F
authors.lastname: Sano
mesh_terms: D057446:Hydrodynamics; D060328:Magnetic Phenomena; D055096:Optical Devices; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D013997:Time Factors