Influence of space charge effect on thermal instability of cathode microprotrusion

Due to the high density of the prebreakdown current of explosive electron emission, the space charge effect should be considered in the simulation of the initial thermal instability of explosive electron emission. Based on the metallic microprtrusion model of explosive electron emission, a model dealing with the space charge effect is presented. The simulation results show that the space charge effect could greatly lengthen the delay time of explosive electron emission. According to the simulation, the thermal instability process is strongly affected by the space charge effect of prebreakdown current. The space charge effect of prebreakdown current should not be neglected in the analysis of microprotrusion model of explosive electron emission.