Hits:

Indexed by:期刊论文

Date of Publication:2018-06-01

Journal:PHYSICS OF PLASMAS

Included Journals:SCIE

Volume:25

Issue:6

ISSN No.:1070-664X

Abstract:The time dependence of the spectral emission of atmospheric pressure surface micro-discharge (SMD) in helium has been investigated with a two-dimensional spatial resolution. The time-resolved emission spectra from OH (309 nm), N-2(_)+(391.4 nm), He (706.5 nm), and O (777.4 nm) behave differently. The results indicate that direct electron impact excitation dominates the generation of the plasma emission in the middle part of the rim electrode where the discharge event originates during the initial period. However, the fan-shaped diffusion of the discharge patterns head is principally due to Penning ionization and charge transfer reaction in later phases. Furthermore, the dynamic evolution of SMD emission pattern has a bullet-like structure in the negative half cycle while it looks like a glow in the positive half cycle. It implies that the polarity of applied voltage plays an important role in the dynamics of the SMD emission patterns. Published by AIP Publishing.