[Measurement of plasma parameters in cluster hexagon pattern discharge by optical emission spectrum].

The cluster hexagon pattern was obtained in a dielectric barrier discharge in air/argon for the first time. Three plasma parameters, i. e. the molecular vibrational temperature, the molecular rotational temperature and the average electron energy of individual cluster in cluster hexagon pattern discharge, were studied by changing the air content. The molecular vibrational temperature and the molecular rotational temperature were calculated using the second positive band system of nitrogen molecules (C 3IIu --> B 3IIg) and the first negative band system of nitrogen molecular ions (B 2Sigma(u)+ --> Chi2 Sigma(g)+). The relative intensities of the first negative system of nitrogen molecular ions (391. 4 nm) and nitrogen molecules emission spectrum line (337.1 nm) were analyzed for studying the variations of the electron energy. It was found that the three plasma parameters of individual cluster in cluster hexagon pattern increase with air content increasing from 16% to 24%.

[Study on plasma parameters in diffuse discharge with semispherical electrod by optical emission spectrum].

The diffuse discharge plasma in air was observed in a dielectric barrier discharge with two semispherical water electrodes. The variations of vibration temperature, rotation temperature, and average electron energy as the function of the applied voltage were studied by emission spectroscopy. The vibration temperature and the rotation temperature were calculated through the second positive band system (C3Pi(u)-->B3Pi(g)) of N2+ and the first negative band system (B2 Sigma(u+)-->Chi2Sigma(g+)) of N(2+) respectively. The average electron energy was studied by intensity ratio of 391.4 and 337.1 nm. It was found that the rotation temperature increases with the applied voltage increasing, while the vibration temperature and the electron energy decrease.

[Spectra line profile and vibrational temperature of bright dot and dark dot discharge in a dielectric barrier discharge].

The emission spectrum line shift and vibrational temperature of the bright dot and dark dot discharges, which are observed in the argon and air dielectric barrier discharge at high temperature for the first time were measured and compared. The line shift of the spectral line of the Ar I (2P2-->1S5) is measured and the vibrational temperature was calculated using by the emission spectral lines of the N2 second positive band system (C3Pi(u)-->B3Pi(g)). The results show that the spectrum line shift of the bright dot discharge channel is larger than that of the dark dot channel, which indicates that the former has higher electron density compared to the latter, and the vibrational temperature of the dark dot discharge channel is higher than that of the bright dot discharge channel.

[Measurement of molecular vibrational temperature of the white-eye pattern in dielectric barrier discharge].

The white-eye pattern, whose cell is composed of a bright dot surrounded by a closed hexagon, was observed in air/ argon dielectric barrier discharge. It was found that the center dot, the vertex of hexagon and the center of hexagon side in a cell have different brightness. By using optical emission spectra, the vibrational temperature in the center dot, the vertex of hexagon and the center of hexagon side was measured, respectively. The variations in the vibrational temperature at these three places as a function of the content of argon in gas mixture were also studied. The vibrational temperature was calculated by emission spectral lines of the N2 second positive band system (C3IIu --> B3IIg). The experimental results show that the vibrational temperature of the center dot, the vertex of hexagon and the center of hexagon side is in the ascending order and decreases with the increase in the content of argon in gas mixture.