[Table of Contents]

Plasma and Fusion Research

Volume 5, S2032 (2010)

Regular Articles


Comparison of Hydrogen and Deuterium Plasmas in ECH Start-Up Experiment in the TST-2 Spherical Tokamak
Osamu WATANABE, Akira EJIRI, Hiroki KURASHINA, Takuya OHSAKO, Yoshihiko NAGASHIMA, Takashi YAMAGUCHI, Takuya SAKAMOTO, Byung Il AN, Hiroyuki HAYASHI, Hiroaki KOBAYASHI, Kotaro YAMADA, Hidetoshi KAKUDA, Junichi HIRATSUKA, Kentaro HANASHIMA, Takuma WAKATSUKI and Yuichi TAKASE
The University of Tokyo, Kashiwa 277-8561, Japan
(Received 9 December 2009 / Accepted 7 May 2010 / Published 10 December 2010)

Abstract

In the TST-2 spherical tokamak, non-inductive start-up experiment using electron cyclotron heating (ECH) at 2.45 GHz are performed. Hydrogen and deuterium discharges were compared after sufficient wall cleaning by Ohmic discharges to ensure discharge reproducibility. After the wall cleaning, wall recycling seemed to be reduced, because additional gas puffing was necessary to sustain a discharge. Even in that case, hydrogen emission measurement revealed the existence of finite wall recycling source. A current jump occurred earlier in the deuterium plasma than in the hydrogen plasma. Except for the timing of the jump, the discharge time evolution and various values such as the plasma current were almost the same for the deuterium and hydrogen plasmas.


Keywords

non-inductive start-up, ECH, current jump, wall discharge cleaning

DOI: 10.1585/pfr.5.S2032


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This paper may be cited as follows:

Osamu WATANABE, Akira EJIRI, Hiroki KURASHINA, Takuya OHSAKO, Yoshihiko NAGASHIMA, Takashi YAMAGUCHI, Takuya SAKAMOTO, Byung Il AN, Hiroyuki HAYASHI, Hiroaki KOBAYASHI, Kotaro YAMADA, Hidetoshi KAKUDA, Junichi HIRATSUKA, Kentaro HANASHIMA, Takuma WAKATSUKI and Yuichi TAKASE, Plasma Fusion Res. 5, S2032 (2010).