Formation of charge-exchange ion flows near the exit from the stationary plasma thruster acceleration channel

Dynamics of ions in the plume of the stationary plasma thruster operating with Krypton

“…3) reveal clearly the presence of fairly significant " radial" and " back" ion flows. As was already noted, the charge exchange of accelerated ions with neutral atoms is the most probable source of " back" ion flows [4].…”

“…In view of the above, research and development works on new krypton SPTs have intensified. Studies of processes in jets of such thrusters are of academic and applied importance: they allow one to examine the efficiency of ionization of propellant particles in an SPT discharge, the formation of accelerated ion flows, and the evolution of secondary processes in jets [3,4]. In the present study, we report the results of investigation of spatial distributions of the plasma parameters and accelerated ion flows in the jet of an experimental krypton SPT-70V thruster model of a new design (with an external accelerating channel diameter of 70 mm and an acceleration zone, within which the greater part of the potential drop is localized, shifted out of the working channel) and " radial" and " back" ion flows and parameters of plasma in the vicinity of the indicated SPT model.…”

“…In view of the above, the examination of the spatial distribution of a flow of accelerated ions and their energy characteristics in the jet of a krypton SPT-70V thruster model was set as one of the goals of the present study. Such data enable one to estimate the influence of the operating thruster jet on structural elements of spacecraft, the influence of incompleteness of the atom flow into ions conversion and the application of a discharge voltage on the acceleration of ions, as well as of the jet divergence, and the velocity spread of ions on thruster efficiency [3,4]. Another goal was to examine the motion directions of ions emerging outside the channel near the exhaust ends of the discharge chamber walls at the boundaries of the primary flow and forming " radial" flows of ions with fairly high energies [3,4] and "…”