New Limiter Concept Using RF Electric Field

研究了一种利用射频电场来保护材料限制器和稳定表面等离子体的新方法，即利用射频场在限制器附近产生的射频势有质动力势垒来保护限制器头部免受等离子体的影响。FR限制器的概念的实验证明，试图使用线性装置（NPX）和螺旋系统（CHS）的等离子体参数，这是比较典型的托卡马克的边缘等离子体。用探针和重中性束探测系统研究了有质动力势垒对边界等离子体势和密度涨落能级的影响。限幅器上的射频功率显著降低了离子密度和波动水平（<10kHz）。限制器边缘上的热点的温度示出通过在CHS中施加RF功率而降低，并且限制器头部上的热通量被证明通过此概念而降低。

A new method to protect a material limiter and stabilize surface plasma by the use of RF electric field has been studied.The limiter head is protected from the plasma by the RF potential ponderomotive force barrier which is produced by the RF the RF field near the limiter. Experimental proof of the FR limiter concept was attempted using the linear device (NPX) and the helical system (CHS) with plasma parameters which are comparable to the edge plasma of typical tokamaks. The effect of the ponderomotive potential barrier on the boundary plasma potential and the density fluctuation level are studied by using probes and heavy neutral beam probing system. The ion density and the fluctuation level (<10kHz) are decreased remarkably by the RF power on the limiter. The temperature of the hot spots on the limiter edge is shown to be decreased by applying RF power in CHS and the heat flux on the limiter head is demonstrated to be reduced by this concept.