HL-1M装置边缘扰动和流速的实验研究

利用一组马赫探针研究HL-1M装置刮离层和边缘等离子体流在欧姆放电、壁硼化、偏压抽气孔栏、偏压电极、低混杂波电流驱动、电子回旋共振加热、弹丸注入、分子束注入、激光吹气和补充送气等情况下的平行流马赫数、离子饱和电流扰动、平行流速度剪切和极向流速度的分布。实验中发现局部等离子体电位快速变化，改变了电场分布，改变了边缘等离子体的流速和方向。从而改善了等离子体约束性能。

Studies of the Edge Fluctuations and Flow Velocity in the HL-1M Tokamak

The characteristics of the plasma flow on the SOL and at the edges of HL-1M Tokamak were systematically studied with a Mach probe array. The characteristics measured include the parallel-flow-Mach-number, the ion-saturation-current-fluctuation, the parallel-flow-velocity-shear and poloidal-flow-velocity in a variety of realistic situations, such as, in Ohmic discharge, in wall boronization, in LHCD and ECRH, in pellet injection, in molecular beam injection, in laser blow-off and gas puffing, at bias pump limiter, at bias electrode. Our interesting finding is the large, abrupt change in potential of a localized plasma, whieh results in a number of changes, for instance, changes in electric field distribution, changes in velocity and direction of the plasma flow at boundaries of the Tokamak. What is most important is that the plasma confinement can be considerably improved by the abrupt change in localized plasma potential.