用偏压限制器控制KT－5C托卡马克等离子体边缘电场的实验研究

在托卡马克ＫＴ－５Ｃ上，我们首次采用可灵活组合的多块限制器进行了施加偏压以控制等离子体边缘电场的实验，结果表明，在本装置上限制器加正偏压优于加负偏压，正偏压改变等离子体边缘电场效果更明显。偏压限制器收集面积、纵场和偏置电压的大小对偏压效果的影响都是敏感的。改变限制器收集面积和偏压导致的边缘电场的变化最终将趋于饱和，另外发现，偏压限制器与等离子体柱的相对位置对等离子体边缘电场的影响也是重要的。

EXPERIMENT FOR CONTROLLING THE PLASMA EDGE ELECTRIC FIELD BY BIASED LIMITERS ON THE KT-5C TOKAMAK

The experiment for controlling the plasma edge radial eletric field using a set of biased limiters which can be easily reconnected has been carried out on the KT-5C tokamak for the first time. It is found that positive biasing is more effective than the negative in modifying the edge electric field. The collecting area of the limiter (perpendicular to the toroidal magnetic field), the strength of toroidal field and the value of the applied biasing voltage can affect the experiment results sensitively. The edge potential will finally be saturated by increasing the collecting area or the biasing vollage (either positively or negatively). It is shown that the relative position of biased limiter to the plasma column can be very important for modifying the edge electric field.