Relaxation of the electron energy in the post-discharge of an He-N2mixture

Abstract
The electron energy distribution function in the post-discharge of a pulsed RF discharge has been measured by means of a time-resolved Langmuir probe technique, in an He-N2 mixture at 0.2 and 0.5 Torr. Within the limits of the technique, it is shown that the presence of N2 has the effect of slowing the decay of the electron average energy, this being more evident the higher is the N2 content of the mixture. This phenomenon can be ascribed to the presence of long-lived vibrational or electronic states in the afterglow which release their energy to the electron gas.