POWER DEPENDENCE OF ECR CD EFFICIENCY AT THE SECOND HARMONIC IN T-10

摘要

Non-linear effects of input microwave power on CD efficiency for second harmonic ECR waves in T-10 experiments are analysed with the aid of the new numerical code OGRAY-1.0. A substantial influence of the spatial profiles of plasma parameters is noted. The maximum dimensionless absorbed power p = T_e(dP/dV)/nT_e on the ray trajectory is used as a measure of non-linearity. Non-linear enhancement of CD efficiency without substantial distortion of the absorption profile is observed for p > 0.01. For p ≈ 1, quasi-linear distortion of the absorption profile occurs. The non-linear gain in CD efficiency grows with the rise of the longitudinal refraction index N_N (or launching angle).