Early Stage of Pulsed High Current Discharge with Copper Powder

Abstract

Early phase of powder plasmas powered by a pulsed high current discharge was examined by use of high-speed cameras and a laser shadowgraph and schlieren techniques. Initial electrons created by a pre-ionization discharge collide with both an anode and powder particles, of which surfaces evaporate after then. Evaporation of the particle by electron collision initially occured in the hemisphere surface which is close to cathode side. Since vaporization of the anode far exceeds that of the particles, discharge characteristics is almost similar to that of vacuum sparks in which expanding anode plasmas are observed. In order to suppress the developpment of the anode plasma, reduction of the effective anode area by varying the anode shape was examined.

Formation of Ethanol Filament and Its Pulsed Discharge for Microplasma Generation

“…As long as a spatially isolated small structure is obtainable, any state of matter such as gas, 2) liquid, 3) or solid 4) is applicable for the method. In the case of liquid, one can use a droplet or a filament as the initial material.…”