Simulated performance and characterisation of a small ring-cusp gridded ion engine using alternative propellants

Abstract

Nowadays, xenon is the most common propellant used for space applications as a result of its favourable physical and chemical properties. However, it is particularly expensive due to its limited availability and complex extraction process. Therefore, the search for a viable alternative is gaining importance to meet the need for a growing diversification of satellites, missions, and manoeuvres. This aspect has been boosted by the “New Space” revolution, which demands cheaper and simpler systems even at the cost of lower performance.
This thesis refers to the investigation to assess the possibility of replacing xenon as the main propellant for gridded ion engines. Krypton and a mixture of xenon and krypton were identified as possible alternatives. While only limited publications, dating back a few decades, exist for krypton with gridded ion engines and the majority were focused on large size discharge chambers, the literature on mixture of xenon and krypton with this type of thrusters is non-existent.
Two experimental campaigns were carried out to investigate the performance gap between xenon and the two alternative propellants: one with a small ring-cusp gridded ion engine, operated in discharge-only mode, and one with a hollow cathode, operated in diode mode. Both the thruster and the cathode were originally designed for xenon and, therefore, the results of these experiments represent a baseline and worst-case scenario for the alternative propellants. In both setups, the investigation was supported by an array of diagnostics tools (e.g. thermocouples and Langmuir probes) to allow an internal characterisation of the discharge chamber’s phenomena and the measurement of the plasma properties (i.e. electron temperature, and plasma potential and density) with the objective to identify possible areas for improvement and optimisation (e.g. ion optics, operational points, cathode orifice, etc.).

More information

Identifiers

ORCID for Nazareno Fazio: orcid.org/0000-0003-0968-304X

Catalogue record

Export record