Improvement of ECH-driven plasma current startup by control of pitch angles of fast tail electrons

实现核聚变电站的问题之一是降低建设成本。虽然小纵横比环形等离子体与细长中心螺线管有望降低成本，但需要非感应式启动等离子体电流的替代方案。在各种无感启动方法中，ECH/ECCD方法因其不需要等离子体附近的结构而具有广阔的应用前景。理论和实验表明，从低场侧注入的斜O波在内壁镜面反射的X波模转换对于大型聚变装置的启动是有用的。在低宽高比环面实验装置的一个小装置中，也表明了电子伯恩斯坦波在上层混合共振层的模式转换对启动等离子体电流是有用的。

One of issues to realize fusion power plant is reduction of the construction cost. While low aspect ratio torus plasma with a slim center solenoid is promising for cost reduction, non-inductive alternative to start up the plasma current is required. Among various methods of non-inductive start up the ECH/ECCD method is promising since it needs no structure in the vicinity of the plasma. It has been theoretically and experimentally shown that X wave mode-converted upon mirror reflection on the inboard wall from the oblique O wave injected from the lower field side is useful for the start up in large fusion devices. It has been also shown in a small device of the Low Aspect ratio Torus Experiment device that Electron Bernstein waves mode-converted at the upper hybrid resonance layer is useful to start up the plasma current.