In order to improve the efficiency of high voltage pulse lithotripsy

we experimentally researched rock breakdown on solid-liquid interface with coaxial electrode. We designed an experimental apparatus based on the principle of high voltage pulse discharging. The coaxial electrodes were placed on the surface of solid dielectric in liquid insulation dielectric. Many eletro-pulse materials destruction experiments were carried out under the conditions of different solid dielectrics in different liquid phase dielectric. We extracted potential parameters in different modes of discharge by comparing and analyzing the data of voltage and current waveform. The results show that the delay time of liquid dielectric breakdown is longer than that of solid dielectric in corresponding environments

and the delay time is negatively correlated with the liquid medium of conductive particles. The breakdown of the resistance variation coefficient of liquid dielectric breakdown resistance is larger than that of solid dielectric breakdown resistance in corresponding environments at least one order of magnitude. According to the analysis

we have achieved that the breakdown delay time and the breakdown of the resistance variation coefficient can be as parameters to discriminate discharge mode.