Modeling in front of a plasma profile of a set of traveling wave antenna sections in view of the ion cyclotron range of frequencies heating of the fusion reactor

Abstract

An upgraded version of the fast semi-analytical code ANTITER-II is used to model the traveling wave antenna (TWA) sections of any arbitrary number of radiating straps facing a low coupling plasma profile with their feeding system. The code computes the Y, Z and S matrices of the antenna array from which the performances of the TWA sections and of their feeding system are deduced as a function of the geometrical parameters of the TWA. The model incorporates the feeding of each section by a resonant ring circuit that re-circulates its output power. The cases of straps grounded at one of their ends (L grounding) or in their center (T grounding) are also compared. This model is extended to a number nB of TWA sections of nstr straps with arbitrary positions in the y, z plane (i.e. machine wall). The full matrices of the resulting array of nstrnB straps are derived and connected to the resonant ring circuits feeding each TWA sections to incorporate the feeding in the model. Examples of toroidal and/or poloidal set of sections with T or L grounding and symmetric or asymmetric k// spectra are analyzed. First conclusions for the design of a set of TWA sections for the reactor are already drawn.