Dynamics of a nonequilibrium discharge in a converging cylindrical wave under the condition of intensive gas heating

Abstract

The dynamics of a nonequilibrium high-frequency discharge under high pressure in a converging cylindrical wave under the condition of intensive gas heating is investigated. The gas dynamic processes are considered within the framework of the isobaric approximation. It is shown that the space-time evolution of the discharge depends essentially on the amplitude of the wave. At small amplitudes, where the field intensity is only slightly above break-down in the centre, at first the electron temperature Te and density rapidly (explosively) grow up to comparatively high values. The size of the arising plasma formation is much smaller than the wave-length and the skin layer (plasma cord). Later, due to the strong screening by the discharge plasma, the field weakens and ne, Te slowly get smaller (in fact it is the regime of dying plasma cord). At large amplitudes and average gas-heating speed the diminishing of the gas density occurs to be an accompanying factor and the dynamics of the discharge is the same as in the case of nonessential Joule heating.