Gas temperature measurement in a dielectric barrier discharge by argon atomic spectral line

We present a method and results for measurement of gas temperature in a sub-atmospheric dielectric barrier discharge by using van der Waals broadening of an atomic spectral line. The Stark shift of argon 696.54 nm is measured by comparing the profiles with an unshifted line emitted from an argon discharge at a pressure less than 10 Pa. It is used to determine the electron density and Stark broadening. An asymmetrical deconvolution procedure is applied to separate Gaussian and Lorentzian profile from the measured spectral line. By subtracting the Stark broadening and partial Lorentzian instrumental broadening from the Lorentzian broadening, the van der Waals broadening is obtained and then the gas temperature is estimated. It is found that the gas temperature in a dielectric barrier discharge increases with the increase of gas pressure.