Ionization rate in the presence of runaway electrons

Publisher Website
Google Scholar
Abstract
The role of a fast electron population, produced by the strong electric field driving the axial current in a capillary discharge, can be essential in order to justify the appreciable concentration of highly charged C ions (C5+, C6+) as observed in many experiments with low electron temperature. Under the assumption that a quasistationary state is established during the discharge, the runaway electron distribution function is determined analytically for Zeff>1, following the approximated method developed by Lebedev [A. N. Lebedev, Sov. Phys. JETP 21, 931 (1965)]. The strong enhancement of the ionization rate, due to the presence of an electron tail in the energy range of the ionization potential, is then demonstrated.