A Mock-Up Test of a Ceramic-Free Antenna Feeder of the Ion Cyclotron Heating System for Next-Generation Tokamaks

We propose a ceramic-free antenna feeder employing a ridged waveguide as a local support in an ion cyclotron range of frequency (ICRF) antenna for next-generation tokamaks. A one-quarter scale mock-up model of the all metal waveguide designed for the ICRF system in the international thermonuclear experimental reactor (ITER) is fabricated, and electrical characteristics of the model, including the coaxial line-to-waveguide converters are measured. Power reflection coefficient of the model including the coax-waveguide converter at the input coaxial line is estimated to be less than 15% when below the cut-off frequency of 107 MHz and less than 3% when above the cut-off frequency. It is found that this ceramic-free antenna support employing a ridged waveguide is suitable for the ICRF antenna for next-generation tokamaks.