A sinusoidally driven needle-to-plane discharge in flowing helium at atmospheric pressure was
investigated by means of electrical, optical and spectroscopic (VUV, UV and OES) measurements.
‘Bullet-like’ behaviour of the discharge was observed and investigated with special interest towards
velocities and size of the ‘forward bullet’. The influence of the discharge gap and oxygen admixture
on the discharge properties was analysed. The focus of this paper is on experimental results,
showing discharge development within six phases. Among these, four types of bullets are observed
with respect to the direction of the gas flow and applied voltage polarity. Temporally resolved
photography shows the formation of an atmospheric pressure glow discharge subsequent to the
propagation of the ‘forward bullet’. For the greatest gap of 15 mm, the plasma activity was
restricted towards the positive voltage polarity. The discharge development under the oxygen
admixture showed a delayed current pulse for the negative voltage slope, with a steep rising flank.
We conclude that the main movement of the bullets in our setup does not depend on the gas flow but
on the electrical field direction.
Mendeley saves you time finding and organizing research
Choose a citation style from the tabs below