EVALUATION OF ECE SPECTRA IN A TOKAMAK WITH TORUS GEOMETRY AND APPLICATION TO ELECTRON TEMPERATURE MEASUREMENT

The characteristic of ECE spectra in a tokamak has been studied taking account of the torus geometry. Although the structure of the magnetic field (B) in the sight line is different in the cases of changing the angle between the sight line and B, the radiation temperature of ECE are almost same in the low frequency side of 2nd harmonic, electron temperature profile [T_e^th(r)] in low field side can be obtained by changing the angle between the B and sight line. The effect of supra-thermal electron on the radiation temperature is also evaluated in the case of bi-Maxwellian. In the uniform density case of supra-thermal electron (n_e^sp), small amount of supra-thermal affects the radiation temperature. For instance, when the n_e^sp is 0.4% of thermal electron density results in 10% of deviation of electron temperature in the case of T_e^th(0) = 20 keV.