Three-dimensional gas temperature measurements in atmospheric pressure microdischarges using Raman scattering

Spatially resolved three-dimensional rotational Raman spectroscopy of ground state nitrogen was used to measure the gas temperature (T-g) in a normal dc glow microdischarge (300 mu m gap between 0.5x0.05 mm(2) parallel electrodes) in pure N-2. An original backscattering confocal optical system with a spatial resolution of similar to 40 mu m was developed for collecting Raman spectra. Gas temperatures were measured at several points across the gap as well as along the axis perpendicular to the discharge plane. T-g peaked near the cathode and was 1200 K in the negative glow of a 500 Torr, 20 mA discharge. (c) 2006 American Institute of Physics.