AVS 53rd International Symposium
    Plasma Science and Technology Wednesday Sessions
       Session PS2-WeA

Paper PS2-WeA5
Spatially Resolved Gas Temperature Measurements in an Atmospheric Pressure DC Glow Microdischarge with Raman Scattering

Wednesday, November 15, 2006, 3:20 pm, Room 2011

Session: Atmospheric and Microplasmas
Presenter: S.G. Belostotskiy, University of Houston
Authors: S.G. Belostotskiy, University of Houston
Q. Wang, University of Houston
V.M. Donnelly, University of Houston
D.J. Economou, University of Houston
N. Sadeghi, Universite J. Fourier de Grenoble, France
Correspondent: Click to Email
Spatially resolved rotational Raman spectroscopy of ground state nitrogen N@sub 2@(X@super 1@@SIGMA@@sub g@@super +@) was used to measure the gas temperature (T@sub g@) in a nitrogen dc glow microdischarge (gap between electrodes d ~ 500 µm). An original backscattering, confocal optical system was developed for collecting Raman spectra. Stray laser light and Raleigh scattering were blocked by using a triple grating monochromator and spatial filters, designed specifically for these experiments. The optical system provided a spatial resolution of <100 µm. Gas temperatures were determined by matching experimental spectra to model spectra obtained by convolution of theoretical line intensities with the apparatus spectral resolution, with Tg as the adjustable parameter. T@sub g@ was determined as a function of pressure and discharge current density (P = 400 - 760 Torr, j@sub d@ = 200 - 1000 mA/cm@super 2@). Midway between the electrodes, T@sub g@ increased linearly with j@sub d@, reaching 420 K at 1000 mA/cm@super 2@ j@sub d@ for a pressure of 720 Torr. Spatially resolved gas temperature measurements will also be presented and discussed in combination with a mathematical model for gas heating in the microplasma.