Hannover 2016 – wissenschaftliches Programm
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P: Fachverband Plasmaphysik
P 27: Low Temperature Plasmas III
P 27.1: Vortrag
Freitag, 4. März 2016, 11:00–11:15, b305
The breakdown process in an atmospheric pressure parallel-plate nanosecond discharge — •Bang-Dou Huang1,2, Keisuke Takashima3, Xi-Ming Zhu2, and Yi-Kang Pu1 — 1Department of Engineering Physics, Tsinghua University, Beijing 100084, P. R. China — 2Institute for Plasma and Atomic Physics, Ruhr-University Bochum, Bochum 44801, Germany — 3Department of Electronic Engineering, Tohoku University 6-6-05 Aoba Aramaki, Aoba-ku, Sendai, MIYAGI 980-8579, Japan
The breakdown process in an atmospheric pressure nanosecond discharge with parallel-plate electrodes in helium/argon mixture is investigated by temporally and spatially resolved OES. The electric field is obtained from the Stark splitting of the He I 492.1 nm line. Two effective Te, i.e. Te, high and Te, low, are obtained, using the emissions from helium and argon lines and a simple time-resolved collisional-radiative model. Compared with the nominal average electric field (V/d), the field is greatly enhanced at the ionization wave front and is significantly weakened behind the wave front, as predicted by a fluid model. The value of Te, high is much larger than that of Te, low, which indicates that an elevated high energy tail in the EEPF is built up under the strong electric field during the breakdown process. Initially, the spatial distribution of Te follows that of the electric field. However, at the end of the breakdown period, the location of the highest Te is shifted away from that of the strongest electric field (in the cathode sheath). This indicates the existence of non-local effects, which is supported by the result from a simple Monte-Carlo simulation.