An Iodine Feeding System for Hall-effect Electric Propulsion

Iodine possesses several features which make it a promising alternative propellant for electric propulsion applications in a xenon-replacement perspective. It has good ionisation properties, it stores as a low pressure solid and it costs a tenth as much as xenon. This paper reviews a selection of the recent research activities carried out by the University of Pisa in collaboration with Sitael S.p.A., in the framework of an ESA TRP project, aimed at the development of an iodine feeding system for a 200 W class Hall-effect thruster. The paper is focussed on the description of a first prototype of iodine feeding system which has been designed, manufactured and tested. The main features of a reduced order model of the system are also described. A gas kinetics approach has been used to model the iodine vapour transport properties (viscosity and thermal conductivity). The model has been validated against experimental data. Despite its simplicity, the model has proved to be a reliable tool for design of new iodine feeding system prototypes and experimental data interpretation.