Discharge domain in dielectric barrier discharges in air at atmospheric pressure

摘要

Lifetime of micro-discharge filaments in dielectric barrier discharge in air at atmospheric pressure is very short and high temporal resolution device is necessary to study time correlation between micro-discharge filaments. In this paper, a simple optical method is introduced to study time correlation between micro-discharge filaments in dielectric barrier discharge in air at atmospheric pressure by photomultiplier tubes. The waveforms of light emission indicate that the discharge burst within each half cycle of applied voltage consists of a series of discharges pulses. This experimental phenomenon shows that the discharges of two or more filaments would overlap in time. By time correlation study, it is found out that discharge filaments can be categorized to some groups according their spatial position. The filaments can volley almost at the same time within neighboring space whose dimension is less than 3 × 3mm~2. A discharge domain is proposed to denote the group of discharge filaments that volley at the same time and exist in a neighboring space. The temporal behavior of filaments belong to one domain is investigated in many applied voltage cycles. The probability distribution function of the intervals for the discharge filaments in a domain is given at last. The delay time between breakdown moments of two filaments in one domain varies within the range of a few ns order. The physical mechanism involved in photo-ionization is presented to interpret the domain formation.