OH density and temperature measurement in coaxial cylinder DBD reactor under atmospheric pressure humid air

摘要

Behaviour of radicals in non-thermal plasma is worth clarifying in order to interpret the chemical reaction processes in the plasma gas treatment. Inside the coaxial cylinder dielectric barrier discharge (DBD) reactor, the spatial distribution of relative density and rotational temperature of OH radicals are measured in pulsed barrier discharge under atmospheric pressure using laser-induced fluorescence (LIF) method. OH radicals are produced in the secondary streamer region. The OH rotational temperature increases within tens-hundreds of microseconds, caused by vibrational energy relaxation. The temperature in the coaxial DBD reactor rises slower and reaches lower than that in needle-plane corona discharge. There is a difference in temperature rising pace between near the anode and center of the discharge gap. It indicates that the acceleration of vibrational energy transfer mainly occurs in the secondary streamers.