title: Development of polarization-controlled multi-pass Thomson scattering system in the GAMMA 10 tandem mirror.
abstract: In the GAMMA 10 tandem mirror, the typical electron density is comparable to that of the peripheral plasma of torus-type fusion devices. Therefore, an effective method to increase Thomson scattering (TS) signals is required in order to improve signal quality. In GAMMA 10, the yttrium-aluminum-garnet (YAG)-TS system comprises a laser, incident optics, light collection optics, signal detection electronics, and a data recording system. We have been developing a multi-pass TS method for a polarization-based system based on the GAMMA 10 YAG TS. To evaluate the effectiveness of the polarization-based configuration, the multi-pass system was installed in the GAMMA 10 YAG-TS system, which is capable of double-pass scattering. We carried out a Rayleigh scattering experiment and applied this double-pass scattering system to the GAMMA 10 plasma. The integrated scattering signal was made about twice as large by the double-pass system.
authors.affiliation: Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki, Japan. yosikawa@prc.tsukuba.ac.jp
authors.forename: M
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: R
authors.initials: R
authors.lastname: Yasuhara
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authors.initials: M
authors.lastname: Morimoto
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authors.lastname: Shima
authors.forename: J
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authors.lastname: Kohagura
authors.forename: M
authors.initials: M
authors.lastname: Sakamoto
authors.forename: Y
authors.initials: Y
authors.lastname: Nakashima
authors.forename: T
authors.initials: T
authors.lastname: Imai
authors.forename: I
authors.initials: I
authors.lastname: Yamada
authors.forename: K
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authors.lastname: Kawahata
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authors.lastname: Funaba
authors.forename: T
authors.initials: T
authors.lastname: Minami