A SIMPLE SPECTROSCOPIC METHOD FOR DETERMINING THE TEMPERATURE IN H_(2)O-AR THERMAL PLASMA JET

摘要

A simple spectroscopic method has been developed for characterizing atmospheric high temperature plasma jets in gas mixtures containing hydrogen. It is based on the measurement of one spatially resolved spectrum comprising hydrogen H_(beta) line and ionic lines of other plasma species, and the assumption of local thermodynamic equilibrium. A few characteristic spectral quantities from the measured spectra are used to determine both the temperature and the composition simultaneously. The applicability of the method is illustrated for the case of H_(2)O-Ar DC arcjet in a wide range of plasma temperature and mole fractions of plasma species. It is shown that at least in the jet core the assumption of partial LTE appears to be valid. The method is suitable for ready monitoring of industrial plasmas.