Density and translational temperature measurements of neutral atoms in a glow discharge using coherent Rayleigh scattering

Abstract

Dual-colour single-shot coherent Rayleigh scattering (CRS) is utilised to simultaneously measure the temperature and relative number density in a weakly ionised DC glow discharge. The discharge is produced using xenon gas at a pressure of 15 Torr. By analysing the lineshapes, both the translational temperature and relative number density of neutral xenon atoms are obtained. Measurements at the centre of the discharge are obtained as a function of discharge current. Additionally, spatially resolved measurements are performed across the discharge at an operating discharge current of 15 mA. The spatial results are compared with a one-dimensional radial fluid model of neutral gas flow informed by a 0D plasma global model of the glow discharge. The comparison shows good agreement, demonstrating the capability of CRS toward diagnostics for weakly ionised, low temperature plasmas.