Positive Short-Pulse Corona Discharge Charging of Aerosol Particles

Abstract

Experiments of charging particles by positive short-pulse corona discharges have been carried out. The experimental results show that the number of negatively charged particles was more than that of positively charged ones. The number ratio of the negatively charged particles to the positively charged ones can reach 2:1. The theoretical analysis demonstrates that the positive short-pulse corona discharges include both streamer and corona discharges. The positive streamer discharges consist of many nonthermal plasma leads (streamers) of the branch type, which have high ionizability and propagate rapidly from anode to cathode with the aid of ionization by light. The streamer discharges are at the prebreakdown stage. The positive corona discharges have a thin ionization layer around the anode and most of the interelectrode space is a positive-ion-charging region. The process of charging particles in positive short-pulse corona discharge can be divided into four stages. The free electron charging, which is produced by positive pulsed streamer discharges, is a significant process for charging particles in positive short-pulse corona discharges.