Electron Density and Temperature Measurement by Stark Broadening in a Cold Argon Arc-Plasma Jet at Atmospheric Pressure

Abstract

Determination of both the electron density and temperature simultaneously in a cold argon arc-plasma jet by analyzing the Stark broadening of two different emission lines is presented. This method is based on the fact that the Stark broadening of different lines has a different dependence on the electron density and temperature. Therefore, a comparison of two or more line broadenings allows us to diagnose the electron density and temperature simultaneously. In this study we used the first two Balmer series hydrogen lines Hα and Hβ for their large broadening width. For this purpose, a small amount of hydrogen was introduced into the discharge gas. The results of the Gigosos–Cardenoso computational model, considering more relevant processes for the hydrogen Balmer lines, is used to process the experimental data. With this method, we obtained reliable electron density and temperature, 1.88 × 1015 cm−3 and 13000 K, respectively. Possible sources of error were also analyzed.