Main Physical Features and Processes Determining the Performance of Stationary Plasma Thrusters

Abstract

The main physical features and processes determining stationary plasma thrusters (SPTs) performance levels are considered in this paper, including ionization processes and ion dynamics in the accelerating channel, as well as the results of SPT design optimization, factors determining SPT lifetime, and the possibilities of simulating the plasma particle dynamics in the accelerating channel and in its plume. Nomenclature B, Br, Bopt = magnetic eld induction, its radial component, and the optimum B value, respectively d, bc = accelerating channel mean diameter and its width, respectively E, Ez = electric eld intensity and its z component, respectively e = electron charge F = thrust hc = cycloid height, 22mE /eBz r Id = discharge current Ii = ion current Im = current corresponding to the mass ow rate through the accelerating channel, (mÇ a/M)e jez = z component of electron current density jH = Hall current density j ’ = normal ion current component at surface Ka, , Kh, KwKa9 = numerical factor KM = scaling factor Ks = sputtering yield factor Kl << 1 = numerical factor Kj = surface erosion rate factor La = length of accelerating channel L*a = length of the self-consistent accelerating layer LB = characteristic width of Br(z) distribution l, l0 = magnetic system element sizes M = ion and atom mass m = electron mass mÇ, mÇ a, mÇ i = total mass ow rate in a thruster, mass ow rate through the accelerating channel, and mass ow rate of ions, respectively Na = atom ow rate density, na?Vaz Nd = discharge power, Ud? Id Nsp = speci c power, Nd/Sc na, ni, ne = concentrations of atoms, ions, and electrons, respectively q = ion charge r̄, Dr ̄ = normalized coordinates Sc ’ pd?bc = accelerating channel cross-sectional area SM = magnetic core element cross-sectional area Sv(g, «i) = volumetric sputtering yield