High Power Microwave Test System andSimulated Experiments for HT-7

Abstract

In lower hybrid current drive (LHCD) experiments in HT-7, LH wavecoupled to the plasma from 12 klystrons is launched by a phasedmulti-junction grill. High power microwave reflection or arc, whichthreatens the klystrons, the wave-guide ceramic windows and thevacuum of the tokamak, occur sometimes during the experiments. Forthe sake of safety, a high power microwave test system to performsimulations was developed. In the test experiments, the klystron andwindow can be well protected with an optimized microwave monitor anda PIN switch. The layout of the test system and the simulatedexperiments for HT-7 are described in this paper.