Study of demixing in C–F plasma produced in a capillary discharge

Abstract

The spatial distribution of chemical elements in plasma produced by a pulsed discharge in a capillary made of polytetrafluoroethylene has been studied by methods and means of optical spectroscopy. It has been found that the ratio of the molar fractions of fluorine and carbon differs significantly from that in the polymer wall and varies nonmonotonically along the radius of the plasma jet emerging from the capillary. The performed qualitative analysis of the intensity and direction of a number of competing diffusion fluxes involving C, C+, F, and F+ indicates both the possibility of the slowdown in the fluorine and carbon demixing, which start from the peripheral zone, and a change in the direction of some of these fluxes in the central zone of the discharge, which is reflected in the measured mole fraction profiles of these elements.