The role of associative ionization reactions in the memory effect of atmospheric pressure Townsend discharges in N <sub>2</sub> with a small O <sub>2</sub> addition
Xi Lin, Clémence Tyl, Nicolas Naudé, Nicolas Ghérardi, Н. А. Попов, Simon Dap
Abstract
Abstract In this work, we investigate the role played by associative ionization reactions in the memory effect of atmospheric pressure Townsend dielectric barrier discharges working in N 2 with a small addition of O 2 . Systematic laser-induced fluorescence measurements are carried out in order to provide the absolute densities of N and O atoms and NO molecules for different oxygen concentrations. The use of these data in a dedicated model allows us, in particular, to estimate the rate of the reaction <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msup> <mml:mtext>N(</mml:mtext> <mml:mtext>2</mml:mtext> </mml:msup> <mml:msup> <mml:mtext>P)+O(</mml:mtext> <mml:mtext>3</mml:mtext> </mml:msup> <mml:mtext>P)</mml:mtext> <mml:mo stretchy="false">→</mml:mo> <mml:msup> <mml:mtext>NO</mml:mtext> <mml:mtext>+</mml:mtext> </mml:msup> <mml:mtext>+</mml:mtext> <mml:mrow> <mml:mrow> <mml:mtext mathvariant="italic">e</mml:mtext> </mml:mrow> </mml:mrow> </mml:math> suspected of playing a significant role. According to the obtained results, this reaction is found responsible for a significant enhancement in the production of seed electrons between two successive discharges at 25 ppm of O 2 , in good agreement with experimental observations. It confirms the importance of this associative ionization reaction in these experimental conditions.