title: Negative ion density fronts during ignition and extinction of plasmas in electronegative gases
abstract: Negative ion density fronts have been shown to occur in electronegative steady-state plasmas with hot electrons. In this Letter, we report theoretical and numerical results on the spatiotemporal evolution of negative ion density fronts during plasma ignition and extinction (afterglow). During plasma ignition, the negative ion fronts are analogous to hydrodynamic shocks. This is not the case during plasma extinction where, although negative ions diffuse freely in the plasma core, the negative ion front propagates towards the chamber walls with a nearly constant velocity.
authors.affiliation: Department of Chemical Engineering, University of Houston, 4800 Calhoun Road, Houston, Texas 77204-4792, USA.
authors.initials: ID
authors.lastname: Kaganovich
authors.initials: DJ
authors.lastname: Economou
authors.initials: BN
authors.lastname: Ramamurthi
authors.initials: V
authors.lastname: Midha