A parametric investigation of repetitively pulsed nanosecond duration discharges in argon

This paper presents the results of investigations studying the influence of adjustable parameters in a plate-to-plate repetitively pulsed nanosecond discharge on the temperature and number density characteristics of argon using the absorption characteristics of a metastable transition. Specifically, the effects of pulse energy, pulse repetition frequency and gas pressure on the temperature and number density distributions of metastable argon have been quantified using diode laser absorption spectroscopy. The metastable argon 1s₃ state is optically probed by current scanning a vertical cavity surface emitting laser diode over the 1s₃→2p₄ metastable transition at 794:8176 nm. The importance of the fast detection method used to make time-resolved measurements, the effect of the parameters on the translational temperature and number density of metastable argon and the spatial variation of temperature at three different locations between two at plate electrodes are discussed in this paper. Our measurements show that, for small input pulse energies, the peak temperature of the argon atoms in the 1s3 state can exceed ambient room temperature by up to an order of magnitude.