Streamer-like pulses initiated by oxide breakdown: mechanism and mode transition in negative silicon needle corona discharge

Abstract In negative corona discharge, silicon needle electrodes exhibit discharge behaviors distinct from their metal counterparts, characterized by the emergence of a ‘streamer-like pulse’ phenomenon with current amplitudes reaching several hundred microamperes. To unveil the underlying physical mechanism, this paper conducts a systematic investigation into negative corona discharge of silicon needle by combining experimental diagnostics and numerical simulations. Experimental results indicate that the generation of streamer-like pulses is closely related to the silicon dioxide (SiO 2 ) oxide layer formed on the silicon needle surface during discharge. The periodic breakdown and recovery of this oxide layer are key to triggering the intermittent streamer-like pulses. Based on this finding, a two-dimensional axisymmetric fluid dynamics model is established, and it successfully simulate the spatiotemporal evolution of particles during the streamer-like pulses. Simulation results demonstrate that upon the breakdown of the oxide layer at the needle tip, the tip potential surges sharply. It leads to a significant increase in the spatial electric field and elevates electron and ion densities by an order of magnitude, which induce the streamer-like pulses. Furthermore, with a negative ion (O 2 − ) dissociation mechanism, the model accurately reproduces the mode transition from pulsed discharge to pulseless glow discharge under high voltage. And it reveals that a dynamic equilibrium in the spatial distribution of charged particles is the foundation for forming stable glow discharge.