Fundamental Physics and Engineering of Nanosecond-Pulsed Nonequilibrium Microplasma in Liquid Phase without Bubbles

Abstract : The team has demonstrated the possibility of formation of non-equilibrium microscale plasma in the liquid phase and studied the dynamics of excitation and quenching of non-equilibrium MPD in liquid water: the dynamics of the high-voltage nanosecond and subnanosecond pulsed discharge in water without bubbles was investigated; liquid plasma generation without formation of gas bubbles was demonstrated; up to 5000 km/s propagation velocity was observed for a subnanosecond discharge; electron densities and temperatures were measured; a mechanisms of nanosecond discharge development in liquid phase was developed. It was shown that liquid phase plasma is not limited to water in which it has been first observed, but may be generated in virtually any liquid. It was shown that conventional Townsend and streamer breakdown mechanisms are limited in liquid by short electron mean-free path and consequently not sufficient mean electron energy. Quasi-homogeneous generation of liquid phase plasma by nano- and subnanosecond high voltage pulses can be attributed to a cold leader-type mechanism that is similar to generation.