Quasioptical modeling of the electron cyclotron emission diagnostic

Abstract

We report the first applications of the quasioptical (QO) code PARADE (PAraxial RAy DEscription) for modeling the electron cyclotron emission (ECE) diagnostic. Geometrical optics (GO) has been exploited to predict the ECE intensity received by an antenna, but is not sufficient since GO drops the information lying on the transverse cross section of the antenna sensitivity. Hence, we studied a QO model of ECE measurement based on the PARADE code. By introducing a weighting operator Wˆ, induced by the envelope profile of a wave beam virtually injected from an ECE receiving antenna, an integral equation, formally identical to the conventional GO model, is newly derived from the wave-action conservation law. A QO ECE prediction module −E3 is also newly developed, is applied to the JT-60SA tokamak, and shows that radiation temperature is corrected from conventional GO prediction. The −E3 module and the PARADE code are applicable to any fusion plasma devices. By using this ECE prediction package, more realistic calculations of radiation temperature are expected by taking the actual structure of an ECE receiving antenna and plasma parameters as well.