Principle of an in-situ relative calibration method using a double-pass beam for Thomson scattering diagnostics

Tojo, Hiroshi; Hatae, Takaki; Itami, Kiyoshi

This paper presents detailed principles of an in-situ relative calibration method that determine electron temperature () without using optical relative transmissivity and then provide the optical relative transmissivity. The method requires a double-pass scattering system and signal ratio between the two signals from the forward and back scattering in each spectral channel. Statistical simulation results indicates the method suppress a systematic error in without considering chromatic degradation in optical components due to radiation effect. In this new method, scattering angle () and are important parameters to evaluate the feasibility. It is found that the method is useful in a range of at =10 keV. The statistical error tends to decrease in high measurements regime.