During operation of the ASDEX Upgrade (AUG) ion cyclotron radio frequency (ICRF) system, Tungsten (W)-coated poloidal limiters and structures connected along magnetic field lines to the antenna can be sources of W, which is attributed to sputtering by ions accelerated in radio frequency (RF) sheaths. In order to analyze and optimize the ICRF antenna performance, accurate and efficient simulation tools are necessary. TOPICA code was developed for analysis of ICRF antenna systems with plasma loading conditions modeled with ID FELICE code. This paper presents an initial comparative analysis of two AUG ICRF antennas for a set of model plasma density profiles (with varying density gradient and antenna cut-off distance). The antennas are presently installed in AUG and differ in that one was partially optimized using HFSS code to reduce E∥ near fields. Power transferred to plasma and sheath driving RF potentials are computed.
Radio Frequency Power in Plasmas
- Pub Date:
- December 2011
- plasma density;
- Numerical optimization;
- Plasma sheaths;
- Emission absorption and scattering of electromagnetic radiation