Numerical analysis of ICRF antenna array

A numerical code for the calculation of the coupling between an ICRF wave and a plasma by using the variational principle has been extended so that it can be applied to a phased antenna array. The fundamental parameters, such as the self-consistent current distribution in the antenna, the RF fields excited inside the plasma and the antenna impedance can be evaluated by using this code for various types of antenna arrays. In this paper, the antenna impedance dependence on various antenna parameters and the field structure in the various phasing cases are discussed for the ICRF heating in the Experimental Advanced Superconductor Tokamak (EAST).