New Limiter Concept Using RF Electric Field

研究了一种利用射频电场保护材料限位器和稳定表面等离子体的新方法。限位器头部由靠近限位器的射频场产生的射频电位质动势屏障保护免受等离子体的伤害。利用线性装置（NPX）和螺旋系统（CHS），利用与典型托卡马克边缘等离子体相当的等离子体参数，对FR限制器概念进行了实验验证。利用探针和重中性束探测系统研究了有源势垒对边界等离子体势和密度涨落水平的影响。限制器上的射频功率显著降低了离子密度和<10kHz的波动电平。通过在CHS中施加射频功率，可以降低限制器边缘热点的温度，并且可以降低限制器头部的热流密度。

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.