Inversion techniques to obtain local rotation velocity and ion temperature profiles for the x-ray crystal spectrometer on EAST

Inversion techniques are conducted based on the tangential x-ray crystal spectroscopy (TXCS) geometry on EAST to obtain the local profiles of ion temperature (T_i) and toroidal rotation velocity (v_t). Firstly, local emissivity profiles of the impurity argon are obtained using the asymmetrical Abel inversion. Then, the local v_t and T_i profiles are calculated by considering the local emissivity profiles and the TXCS detailed geometry. In addition, how the changes in the v_t profiles affect the accuracy in the T_i profiles is discussed in detail. It is also found that the line-integrated T_i profiles are becoming less accurate with the increase in the radial gradient in the local v_t profiles. Nonetheless, accurate T_i radial profiles are reconstructed after considering the effects of the emissivity and velocity, which are verified by comparing the inverted v_t and T_i profiles with those local profile measurements from the Charge eXchange Recombination Spectroscopy (CXRS) on EAST.