Gridded Ion Engine; Radiofrequency Ion Thruster; µRIT3.5; Ion Optics System; Grid Erosion; Lifetime Extension; Propellant Additives; Xenon Propellant; Sputtering; Redeposition; Erosion Characterisation; Pit-and-Groove Erosion; Barrel Erosion; Aperture Geometry; Multi-aperture Grid; SEM; Scanning Electron Microscopy; EDX; Energy-Dispersive X-ray Spectroscopy; Micro-Computed Tomography; CT Imaging; Non-destructive Testing; Quartz Crystal Microbalance; QCM; Endurance Testing; R2D2 Vacuum Facility; Universität der Bundeswehr München; TransMIT GmbH; ESA Contract 4000124912/18/NL/KML; Mars Space Ltd; Thruster Lifetime; Material Transfer; Ion Extraction; Back-sputter; Erosion Modelling; Plasma Diagnostics; Langmuir Probe; Retarding Potential Analyser; IEDF; Beam Optics; RF Generator; Electrodeless Discharge; Inductively Coupled Plasma; High Voltage Grids; Additive-enriched Propellant; Vacuum Chamber Effects; Electric Propulsion; ESA-funded Project     «

Gridded Ion Engine; Radiofrequency Ion Thruster; µRIT3.5; Ion Optics System; Grid Erosion; Lifetime Extension; Propellant Additives; Xenon Propellant; Sputtering; Redeposition; Erosion Characterisation; Pit-and-Groove Erosion; Barrel Erosion; Aperture Geometry; Multi-aperture Grid; SEM; Scanning Electron Microscopy; EDX; Energy-Dispersive X-ray Spectroscopy; Micro-Computed Tomography; CT Imaging; Non-destructive Testing; Quartz Crystal Microbalance; QCM; Endurance Testing...     »

The Lifetime of gridded ion engines is limited by the erosion of the ion optic system. To investigate potential lifetime extension strategies, including those based on propellant additives, a dedicated baseline erosion campaign was initiated. A custom three-grid ion optics set was developed, featuring apertures of varying configurations to resolve different erosion modes, and manufactured from selected materials to allow discrimination of sputtering sources. Erosion characterisation was performed at 0, 100, 500, and 1000 hours of continuous operation using a combination of scanning electron microscopy with energy-dispersive X-ray spectroscopy and, for the first time in this context, micro-computed tomography, enabling non-destructive quantification of grid erosion and alignment without disassembly. Analysis of the ion optics with SEM-EDX showed no detectable redeposition of vacuum chamber materials, including the target, contrary to previous studies. Initial results demonstrate clear trends in erosion profiles between single- and multi-aperture regions and validate the novel CT-based methodology. These findings provide a robust experimental foundation to deepen and extend the current understanding of ion extraction, material transfer within the extraction region and deduce various factors influencing erosion (and re-deposition) inside the ion optic systems. The baseline characterisation experiment continues to run towards 2000h, with subsequent 1000h investigations of propellant additive effects on ion engine lifetime planned.     «

The Lifetime of gridded ion engines is limited by the erosion of the ion optic system. To investigate potential lifetime extension strategies, including those based on propellant additives, a dedicated baseline erosion campaign was initiated. A custom three-grid ion optics set was developed, featuring apertures of varying configurations to resolve different erosion modes, and manufactured from selected materials to allow discrimination of sputtering sources. Erosion characterisation was performe...     »