Dissociative recombination exalts molecular growth in N₂/CH₄ plasmas

¹ Laboratoire de Chimie Physique, UMR 8000, CNRS, Univ Paris-Sud, 91405 Orsay, France
² Université de Versailles Saint-Quentin, CNRS/INSU, LATMOS, UMR 8190, 78280 Guyancourt, France
³ Institut Universitaire de France, 103 Bvd. St-Michel, 75005 Paris, France

^a Corresponding author: pascal.pernot@u-psud.fr

Published online: 29 January 2015

Abstract

We present a comparison of the outcomes of two models of N₂/CH₄ VUV plasmas in two sets of conditions representative of a laboratory experiment and of Titan's ionosphere. The “FullDR” model incorporates all available experimental data on dissociative recombination od C_xH_yN_z⁺ ions thanks to the probabilistic tree technique recently developed in our group, whereas the “Hloss” model implements the H-loss pathways used by default in many models. We show that the FullDR model enhances globally the production of neutrals and ions, through the production of C₂H_x fragments. These species are efficient promoters of molecular growth, notably in the higher pressure conditions of the laboratory experiment.