Study on the radiative excitation rate coefficient of collisional radiative model

Abstract

Optical diagnostics of plasma by a collisional-radiative model combined with optical emission spectroscopy is simple and has many advantages. However, the radiation trapping effect (RTE) disturbs the spectra of plasma and becomes an obstacle to determine the exact electron temperature and density. In order to take into account RTE, the radiative excitation rate coefficient (RERC) was introduced and the analytical expression of RERC was proposed. The hot filament discharge system was constructed and helium spectra were analyzed by the collisional-radiative model with RERC. The characteristics of RERC were discussed against the discharge power and gas pressure.