Investigation Of Plasma Parameters In Microscale Dielectric Barrier Discharge

Homogeneous slot plasma at atmospheric pressure has been generated by a mircoscale dielectric barrier discharge device, which consists of two parallel water electrodes with a distance-adjusting micrometer. Plasma parameters such as electron temperature, vibrational temperature (Tv), and rotational temperature (TR) in the slot discharge plasma have been investigated by means of optical emission spectroscopy (OES).In order to study the plasma parameters in the slot discharge, the range of optical emission spectra 300-420nm during the discharge are measured. The emission spectrum of the N2 second positive band (C3∏u→B3∏g), in which six spectral lines (370.9nm,375.4nm, 380.4nm,394.2nm,399.7nm 405.8nm) ofΔν=-2 (2-4,1-3,0-2) andΔν=-3 (2-5,1-4, 0-3) are chosen to estimate TV. The rotational spectra of 391.4nm in first negative band (B2Σ+u→X2Σ+g) of N2+are used to estimate TR.It is found that the discharge becomes homogeneous with increasing the applied voltage. Both TV and TR remain unchanged along the slot in the homogenous discharge regime. The trend of the Tv with respect to the applied voltage is opposite from that of TR, while the electron temperature keeps constant with the applied voltage increasing.Besides, the change of electron energy in dielectric barrier discharge in the mixture of air and argon at atmospheric pressure is studied by analyzing the emission spectroscopy. It is found that the discharge modes vary from diffuse mode to filamentary mode. The electron excited temperature Te increases from 6200K to12800K when the air concentration increases from 10% to 60%. And the ratios of spectral line intensity of ArⅡand ArI increase with the air concentration increasing. The above results show that the mean electron energy in discharge increases as the air concentration in the mixture of air and argon increases.