The spectroscopic systems for the study of light impurity particle transport in the HT-7 tokamak

Three spectroscopic systems have been developed for the study of light impurity particle transport in the HT-7 tokamak. A visible multi-channel spectroscopic system ( VIS) is used to obtain the brightness distribution of the line emission from ionized light impurities. The profile of Z(eff) (r) has been obtained from the visible multi-channel bremsstrahlung measurement (VB). The system with a rotating hexahedral mirror for space-time resolved spectroscopy measurement from ultraviolet to visible (UV) can provide the brightness distribution of two different emission lines of the light impurities simultaneously. The emissivities by these multi-channel measurements can be obtained by Abel inversion. The measurement was performed in typical OH discharges in the HT-7 tokamak. The carbon particle transport was analyzed. The feasibility of these diagnostic systems for the impurity particle transport study is clearly demonstrated.