Numerical investigation of the Krypton Large IMpulse Thruster

Abstract

Although xenon has long remained the propellant of choice for Hall effect and ion thrusters, its very high price has motivated the investigation of other noble gases as cost-effective options. The development of a 500 W-class Hall thruster at the Institute of Plasma Physics and Laser Microfusion (IPPLM) aims at demonstrating the possibility of operating with krypton at efficiencies close to that obtained with xenon. However, krypton's lower ionization cross-sections need to be compensated by a significant increase of the mass flow rate in comparison with xenon. The subsequent increase of the thermal load has a large impact on the thermal design of the thruster. In order to assess the operating parameters and the thermal fluxes expected during krypton operation, an extensive parametric study of Krypton Large Impulse Thruster's performance was conducted with the one-dimensional time-dependent hydrodynamic HETMAn solver developed at IPPLM. Comparative computations for xenon and krypton confirm that high efficiencies with krypton are possible, with a predicted maximum efficiency only a few per cent below that of xenon, although at mass flow rates ∼50% higher.