Kinetic model of initiation of explosion center on cathode under dense plasma

A kinetic one-dimensional spherically symmetric model of heating of microprotrusion (with curvature radius of 1 micrometer) on the cathode under dense plasma was developed. The kinetic model is a model of 1D3V PIC/DSMC type. The model takes into account the main types of elastic and inelastic collisions of particles in the plasma as well as evaporation and thermo-field electron emission from the cathode. The surrounding plasma parameters in the model are fixed on the boundary placed at the certain distance from the microprotrusion. The applied voltage drop is also fixed on the same boundary. The further evolution of the plasma, current, and cathode temperature is calculated selfconsistently taking into account the influence of the plasma generated during the process. Calculations have shown, that under the certain condition the thermal runaway is develops, and cathode surface temperature reaches the critical one. However, this instability is not caused by microprotrusion joule heating, because the current density is comparatively small (<; 10⁸ A/cm²) at that moment.