Observation of current sheath transition from snowplow to deflagration

Abstract

The measured temporal evolution of the current distribution in a capacitively-driven, coaxial plasma gun discharge is presented. The variation of the delay between admitting a gas puff at the breech of the gun and the discharge of the capacitor bank results in distinct modes of operation. Snowplow occurs for a long time delay or uniform prefill. Deflagration occurs for a short time delay, and is due to the domination of current sheath dynamics by the resistive magnetic field diffusion.