Measurement of Antenna S-Parameters and Application to the Analysis of Resonance Loop System for the ICRF Heating of Fusion Plasmas

It is important to accurately measure the ion cyclotron range of frequencies (ICRF) antenna parameters for the estimation of RF power transmission to Korea Superconducting Tokamak Advanced Research (KSTAR) fusion plasmas. Due to the complexity of a four-loop antenna with mutual couplings, it is not easy to measure those parameters directly. In this paper, a method to determine those antenna parameters more precisely by applying the measured S-parameters to a coupled transmission line model is introduced, and the characteristics of the resonance loop of the KSTAR ICRF system for the heating of fusion plasmas are analyzed by using the identified parameters.