托卡马克中ECW对LHW耦合特性的影响研究

Research on coupling characteristics of low hybrid wave in the presence of electron cyclotron wave in Tokamak

托卡马克中电子回旋波(ECW)与低杂波(LHW)协同作用的实验发现,在LHW维持的等离子体中注入ECW将引起LHW反射系数的减小.本中从理论上研究了LHW的耦合特性与天线口等离子体密度的关系,以及ECW注入后使得等离子体密度从芯部向边缘输运的pump-out现象.通过本文的研究,给出了pump-out现象的基本规律,证实了ECW所致的pump-out使得LHW天线口的等离子体密度有所提高,从而改善了LHW的耦合.这一结论得到了相关实验的支持.研究还指出,在双波协同驱动实验的研究中,由于ECW的pump-out导致边缘密度发生改变时,当对协同净增电流进行修正.

It is found in the experiments on synergy between low hybrid wave （LHW） and electron cyclotron wave （ECW） that the LHW reflection coefficient decreases with the injection of ECW into plasmas in the presence of LHW. In the present paper, the coupling characteristics of LHW, and the pump-out phenomenon caused by ECW are analyzed theoretically. The analysis shows the law of pump-out and the increase of plasma density in the vicinity of the grill mouth caused by pump-out, there by improving LHW coupling. The conclusion is proved by the experiments. Also, considering the change of the plasma density in the vicinity of the grill mouth caused by pump-out in synergy experiments, the synergy current should be corrected.