On the use of two hydrogen bands for spectroscopic temperature measurement in a low-pressure gas discharge

Abstract

We report the results of the optical emission spectroscopy measurements of rotational Trot and translational temperature T tr of hydrogen molecules. The light source was hollow cathode glow discharge with titanium cathode operated in hydrogen at low pressure. The rotational temperature of excited electronic states of H 2 was determined either from the relative line intensities of R branch of the GK → B band or from the P, Q and R-branches of the Fulcher-α diagonal band. The population of excited energy levels, determined from the relative line intensities was used to derive rotational temperature of the ground state of hydrogen molecule.