Temporal-spatial-resolved spectroscopic study on the formation of an atmospheric pressure microplasma jet

摘要

Temporal-spatial-resolved optical emission spectroscopy was employed to shed light on the dynamic behavior and the propagation mechanism of a plasma, originating from a dielectric barrier discharge in helium inside a quartz tube for microplasma jet formation. The plasma propagated, regardless of the gas flow direction, in an accelerating manner at a high velocity up to 17 km/s, suggesting that the propagation was sustained by photoionization. A theoretical analysis demonstrated that the enhancement of the local electric field ahead of the ionization front was mainly responsible for the acceleration of the plasma near the electrode.