Pulsed Power Plasma Devices Based on Hollow and Super-Emissive Cathodes

摘要

The understanding of emission and transport in the pseudospark is complex becausethese are related to a transition between two fundamentally different modes of electron emission. During the previous year we have conducted probe measurements of plasma parameters. We found that fluctuations related to a glow to arc transition can occur wherein smooth current growth is interrupted by cathode spot formation resulting in very rapid rise in current. These results support a view that quenching observed in the pseudospark is a double layer phenomenon that occurs when emission cannot exceed secondary emission produced by ion bombardment. These results are new in that they provide a new explanation of quenching, and demonstrate a valuable probe method.