Thermal stability of the krypton Hall effect thruster

The Krypton Large IMpulse Thruster (KLIMT) ESA/PECS project, which has been implemented in the Institute of Plasma Physics and Laser Microfusion (IPPLM) and now is approaching its final phase, was aimed at incremental development of a ~500 W class Hall effect thruster (HET). Xenon, predominantly used as a propellant in the state-of-the-art HETs, is extremely expensive. Krypton has been considered as a cheaper alternative since more than fifteen years; however, to the best knowledge of the authors, there has not been a HET model especially designed for this noble gas. To address this issue, KLIMT has been geared towards operation primarily with krypton. During the project, three subsequent prototype versions of the thruster were designed, manufactured and tested, aimed at gradual improvement of each next exemplar. In the current paper, the heat loads in new engine have been discussed. It has been shown that thermal equilibrium of the thruster is gained within the safety limits of the materials used. Extensive testing with both gases was performed to compare KLIMT’s thermal behaviour when supplied with krypton and xenon propellants.