Measurement of temperature and electrons density distribution of atmospheric arc plasma by moiré deflectometry technique

In the present paper, the refractive index, electron density and temperature distribution of atmospheric arc plasmas are measured by moiré deflectometry. The deflection angle of rays passing through the plasma is obtained by moiré fringe analysis. Then by using inverse Abel transform integral for this axisymmetric plasma, the refractive index distribution is obtained in different points of plasma and environment. Considering the relation between plasma temperature and refractive index, the spatial temperature distribution of the arc plasma is evaluated. Also, in contrast to conventional models to obtain electron number density, in which the refractive index of plasmas is approximately assumed equal to the electron refractive index, a model is used for accurate and absolute measurement of the electron density profile. This technique is especially suitable for measuring axially symmetric plasma parameters.

► The refractive index, electron density and temperature distribution of atmospheric electrical arc plasmas are measured by moiré deflectometry.
► By using inverse Abel transform integral, the refractive index distribution is obtained in different points of plasma and environment.
► Considering the relation between plasma temperature and refractive index, the spatial temperature distribution of the arc plasma is evaluated.
► In contrast to conventional models to obtain electron number density, an accurate model is used for absolute measurement of the electron density profile.
► By measurement of the refractive index distribution versus distance and definition of plasma, the plasma region is determined.