Interferometer study of radial and axial density evolution and temperature in N2 gas subjected to negative and positive corona discharges

Abstract

In the present paper, we propose to make an optical diagnosis by laser interferometry to determine experimentally the density of neutral particles in a coronal discharge bathing in a gaseous medium N2. We are particularly interested in the measurement of variation of the optical path and therefore of the index of refraction which allows us to highlight the variation of the density of the neutrals in the discharge, and using a computer treatment (Pearce method) the refractive index of the medium is calculated to determine the spatial distribution of density and temperature (radial and axial) at the core of the corona discharge in two different situations (positive and negative). This optical diagnosis also allowed us to quantitatively determine the phenomenon of depopulation of neutral particles. These quantitative and experimental results are interesting because they allow a good correlation between the theoretical results obtained so far