Determination of Nitrogen Atoms Loss Probabilities on Copper, Aluminium, Alumina, Brass and Nylon Surfaces

Abstract

AbstractSummary: Materials exposure to a flowing post discharge jet can induce a significant rise of materials temperature. This increase is related to the recombination of the atomic species produced in the discharge at the surface of the exposed materials, which is a highly exothermic process. At pressures below 10 Torr, this process is the main loss term for the atoms far away from the discharge. Nevertheless, a very small number of reliable data concerning atomic recombination probabilities, γ, is available in the literature. In this work, such data are obtained for the recombination of the nitrogen atoms on five materials (copper, aluminium, alumina, brass and Nylon) by the adjustment between measured surface temperatures and calculated values obtained by a 3D modelling of the post discharge reactor, which includes the enthalpy deposition at the walls. Results show a general decrease of the γ‐values with increasing pressure, as already mentioned by other authors. The sensitivity of the method is also studied.Evolution with pressure of the N‐atom recombination probability γN for aluminium, copper, brass, alumina and Nylon.imageEvolution with pressure of the N‐atom recombination probability γN for aluminium, copper, brass, alumina and Nylon.