An in-situ Relative Calibration Method for Thomson Scattering Diagnostics Using a Double-Pass Scattering System

Abstract

A new method of in-situ relative calibration for Thomson scattering diagnostics using a double-pass scattering system is proposed. The ratio of scattered light signals between the first and second pass depends on electron temperature (T_e), making it possible to evaluate T_e without considering relative transmissivities. The relative transmissivities of each spectral channel can be determined at the same time. The feasibility of the method based on parameters in a JT-60SA Thomson scattering diagnostic is also examined.