Speaker
Dr
Masayuki Yoshikawa
(University of Tsukuba)
Description
In the tandem mirror GAMMA 10/PDX, the yttrium-aluminium-garnet (YAG)- Thomson scattering (TS) system have been constructed for electron temperature and density radial profile measurements. GAMMA 10/PDX is an effectively axisymmetrized minimum-B anchored tandem mirror with thermal barrier at both end-mirrors and a divertor simulation module is installed in the west end cell for divertor simulation experiments. Typical electron density, electron and ion temperatures are about $2\times10^{18}$ m$^{-3}$, 40 eV, and 5 keV, respectively. We can successfully measure the radial profiles of electron temperature and density in the central cell of GAMMA 10/PDX by using the YAG-TS system in a single laser shot. By using the high speed oscilloscopes and their data collection program, we can measure the time dependent electron temperatures and densities every 100 ms in a single plasma shot. Moreover, in order to increase the TS signal intensities, we have constructed a multi-pass TS system of the polarization based system with image relaying optics. The clear multi-pass TS scattering signals from first to eighth passing lasers through the plasma were successfully obtained. The five times larger TS signal intensity were indicated. The multi-pass TS system improves the measurement resolution and time resolution.
Primary author
Dr
Masayuki Yoshikawa
(University of Tsukuba)
Co-authors
Dr
Hisamichi Funaba
(National Institute for Fusion Science)
Dr
Ichihiro Yamada
(National Institute for Fusion Science)
Dr
Junko Kohagura
(University of Tsukuba)
Mr
Koichi Ohta
(University of Tsukuba)
Dr
Makoto Ichimura
(University of Tsukuba)
Mr
Masayuki Chikatsu
(University of Tsukuba)
Dr
Mizuki Sakamoto
(University of Tsukuba)
Dr
Ryo Yasuhara
(National Institute for Fusion Science)
Dr
Ryutaro Minami
(University of Tsukuba)
Dr
Takashi Minami
(Kyoto University)
Dr
Tsuyoshi Imai
(University of Tsukuba)
Ms
Yoriko Shima
(University of Tsukuba)
Dr
Yousuke Nakashima
(University of Tsukuba)
