[Table of Contents]

Plasma and Fusion Research

Volume 5, S2074 (2010)

Regular Articles


Investigation on Optimal Limiter Condition for Stable Sustainment of the Potential Confined Plasma in GAMMA 10
Katsuhiro HOSOI, Yousuke NAKASHIMA, Yuta HIGASHIZONO1), Shinji KOBAYASHI2), Hiroki OZAWA, Ryo YONENAGA, Takashi ISHII, Hisato TAKEDA, Yuusuke YAMAGUCHI, Makoto ICHIMURA and Tsuyoshi IMAI
Plasma Research Center, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
1)
Advanced Fusion Research Center, Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580, Japan
2)
Institute of Advanced Energy, Kyoto University, Gokasho, Uji 611-0011, Japan
(Received 7 December 2009 / Accepted 26 March 2010 / Published 10 December 2010)

Abstract

In GAMMA 10, Electron Cyclotron Heating (ECH) is used for the formation of the axial confining potential (P-ECH) and for the bulk electron heating in central-cell (C-ECH). The paper describes the dependence of the diameter of the iris limiters on the plasma stored energy and the hydrogen recycling. In this experiment, it was observed that the plasma diamagnetism was degraded with the ECH injection and Hα emission was increased near the limiters at the same time. In the case that the diameter of the iris limiters shrunk to 350 mm, the plasma diamagnetism decreased with each ECH by the plasma-limiter interaction. On the other hand, in the case that the diameter of the iris limiters widened to 380 mm, the diamagnetism of the plasma increased with P-ECH, however the plasma collapsed with C-ECH. The above results indicated the close relationship between the iris limiters and the plasma stability. In this paper, we discuss the mechanism of the degradation of the plasma performance and the optimal limiter condition for effective operation of ECH.


Keywords

GAMMA 10, tandem mirror, limiter, hydrogen recycling, Hα, DEGAS, medium-speed camera, ECH

DOI: 10.1585/pfr.5.S2074


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This paper may be cited as follows:

Katsuhiro HOSOI, Yousuke NAKASHIMA, Yuta HIGASHIZONO, Shinji KOBAYASHI, Hiroki OZAWA, Ryo YONENAGA, Takashi ISHII, Hisato TAKEDA, Yuusuke YAMAGUCHI, Makoto ICHIMURA and Tsuyoshi IMAI, Plasma Fusion Res. 5, S2074 (2010).