Design and Set-Up of a Test Equipment for Studies on Iodine-Fed Hollow Cathodes

The use of iodine as a propellant for both ion and Hall type thrusters was proposed in the early 2000s. Thanks to its Xenon-like properties Iodine may be regarded as one of the most promising candidates for replacing noble gas-based propellants. However, due to its corrosive nature, using iodine necessitates additional precautions, especially regarding compatible materials, before its practical utilization. In particular, in cathodes, the high operational temperatures complicate the under standing and prediction of system behavior when exposed to iodine, often resulting in negative outcomes during long-term tests. Also, the necessity to create a compatible cathode feeding system results to be challenging due to issues concerning the compatibility of materials with iodine itself, as well as the need to operate in vacuum with relatively low flow rates. The objective of this work is to design and create an iodine-compatible test equipment composed of a feeding system, a mass flow meter and a hollow cathode, necessary to demonstrate the viability of iodine as an alternative propellant for these devices.