High Power Test of Single Mirror Polarizer for 170 GHz ECCD System

A new concept single mirror polarizer was proposed instead of the conventional two mirror polarizers for electron cyclotron current drive (ECCD) system. The four types of deep groove mirrors, which are installed in a miter-bend, have been tested at a frequency range from 140 GHz to 170 GHz. The optimized single mirror polarizer has been tested at RF power up to 386 kW with pulse duration of 200 ms at 170 GHz. The dependence of ohmic loss of the deep groove mirror on the mirror rotation angle is evaluated with the increment in mirror temperature. The maximum increment in temperature at mirror rotation angle of 35° is 3.4 times larger than the minimum one at 0°.