On the conditions for contraction of a multielectrode corona discharge in He/Ar, Kr, Xe mixtures

The results of an investigation of the contraction of a corona discharge in “needle-grid” and “needle-plane” electrode systems maintained by a constant negative voltage are presented. The discharge was ignited in working media of infrared lasers on p-d transitions of atoms of heavy inert gases (He/Ar, Kr, Xe mixtures). Investigation of the current-voltage characteristics showed that in the mixtures He/Ar/Kr there is no hysteresis on the rising section of the current-voltage characteristic, while hysteresis does appear for a corona discharge in the mixture He/Xe. For voltages ≥5.5 kV on the needles and ballast resistance R_b≥0.5 MΩ dynamical contraction of a corona discharge together with current pulses with f=3–5 kHz and hysteresis loops were found on the descending section of the curve I=f(U), where I and U are the average current and voltage on the discharge gap. The maximum content of atoms of heavy inert gases for [He]=200–300 kPa is [Ar]≤12, [Kr]≤8, and [Xe]≤4 kPa. Pis’ma Zh. Tekh. Fiz. 25, 90–94 (September 12, 1999)