title: Demonstration of improvement in the signal-to-noise ratio of Thomson scattering signal obtained by using a multi-pass optical cavity on the Tokyo Spherical Tokamak-2.
abstract: The multi-pass Thomson scattering (TS) scheme enables obtaining many photons by accumulating multiple TS signals. The signal-to-noise ratio (SNR) depends on the accumulation number. In this study, we performed multi-pass TS measurements for ohmically heated plasmas, and the relationship between SNR and the accumulation number was investigated. As a result, improvement of SNR in this experiment indicated similar tendency to that calculated for the background noise dominant situation.
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Togashi
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ejiri
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Hiratsuka
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakamura
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Takase
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Furui
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Imamura
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Inada
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Kakuda
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Nakanishi
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Oosako
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Shinya
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Sonehara
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Tsuda
authors.affiliation: Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Tsujii
authors.affiliation: Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Wakatsuki
authors.affiliation: Research Institute of Applied Mechanics, Kyushu University, Kasuga 816-8580, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Hasegawa
authors.affiliation: Research Institute of Applied Mechanics, Kyushu University, Kasuga 816-8580, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nagashima
authors.affiliation: Research Institute of Applied Mechanics, Kyushu University, Kasuga 816-8580, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Narihara
authors.affiliation: National Institute for Fusion Science, Toki 509-5292, Japan.
authors.forename: I
authors.initials: I
authors.lastname: Yamada
authors.affiliation: Japan Atomic Energy Agency, Naka 311-0193, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Tojo