Stochastic and Relaxation Processes in Argon by Measurements of Dynamic Breakdown Voltages

Abstract

Statistically based measurements of breakdown voltages U b and breakdown delay times t d and their variations in transient regimes of establishment and relaxation of discharges are a convenient method to study stochastic processes of electrical breakdown of gases, as well as relaxation kinetics in afterglow. In this paper the measurements and statistical analysis of the dynamic breakdown voltages U b for linearly rising (ramp) pulses in argon at 1.33 mbar and the rates of voltage rise k up to 800 V s −1 are presented. It was found that electrical breakdowns by linearly rising (ramp) pulses is an inhomogeneous Poisson process caused by primary and secondary ionization coefficients α, γ and electron yield Y variations on the voltage (time). The experimental breakdown voltage distributions were fitted by theoretical distributions by applying approximate analytical and numerical models. The afterglow kinetics in argon was studied based on the dependence of the initial electron yield on the relaxation time Y0 (τ ) derived from fitting of distributions. The space charge decay was explained by the surface recombination of nitrogen atoms present as impurities. The afterglow kinetics and the surface recombination coefficients on the gas tube and cathode were determined from a gas-phase model.

Memory effect and time correlations in breakdown initiation of DC glow discharge in argon and synthetic air

“…Also, in the ramp experiments with linearly rising voltage pulses, the memory effect was observed to influence the determination of the static breakdown voltage U s . In order to determine U s precisely, it is necessary and sufficient that the rate of voltage rise k → 0 and the relaxation time τ → ∞ (residual active particles should vanish down to the cosmic rays and natural radioactivity level) [19,20].…”