Relaxation of excited species in He/N₂pulsed RF discharges: kinetics of metastable species

The relaxation in the afterglow of excited species produced in a pulsed parallel plate RF discharge of N 2 and/or He has been investigated. Diagnostic aspects about the measurement of the electron energy distribution function by time-resolved Langmuir probe, of the decay of N 2 (A 3 Sigma u + , V=0,4) and He(2 3 S) metastable by LIF spectroscopy, and of N 2 (C 3 Pi u ,V'), N 2 + (B 2 Sigma u + , V') species by time-resolved emission spectroscopy are examined. The features of the relaxation of such species in the afterglow are reviewed in the light of some elementary electron and metastable kinetics which affect the properties of the afterglow in a millisecond timescale.