Correlating metastable-atom density, reduced electric field, and electron energy distribution in a 1-torr argon discharge

Direct measurement of the intensities of the Ar 420.1nm and 419.8nm spectral lines, independent measurement of meta-stable-atom density, electron density, and electron temperature, inferred measurement of reduced electric field, and assumptions of the shape of the electron energy distribution in a 1-torr argon discharge are correlated within the extended-corona-model framework applied to the late stage of a pulsed discharge-tube plasma to determine the reaction rate constants k_ij¹ that are used to predict the 420.1nm to 419.8nm line ratio¹. The model predicts post-transient metastable density. The diagnostic use of optical emission spectroscopy (OES) to follow experimental conditions from start to end of the transient phase of the pulsed discharge is discussed.