A long-duration experimental investigation of grid erosion in a gridded radiofrequency ion engine has been conducted up to 2000 h of operation on xenon propellant. A dedicated multi-material ion optics system with variable aperture configurations was employed to resolve erosion mechanisms under controlled conditions. Grid evolution was characterised using a combined diagnostic approach, including scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX) and micro-computed tomography (micro-CT), enabling both surface and volumetric analysis. The results show distinct erosion behaviour across grid types, with progressive aperture widening and pronounced barrel erosion in the acceleration grid. Micro-CT reconstructions reveal a systematic conical evolution of apertures, with outer diameters exceeding inner diameters, indicating directionality in ion-induced erosion. SEM–EDX analysis confirms material transfer between grids, while no significant contribution from vacuum chamber materials is observed. The findings demonstrate that erosion and redeposition processes are strongly coupled and seem to be governed primarily by internal thruster dynamics, providing new insights into ion optics lifetime behaviour.      «

A long-duration experimental investigation of grid erosion in a gridded radiofrequency ion engine has been conducted up to 2000 h of operation on xenon propellant. A dedicated multi-material ion optics system with variable aperture configurations was employed to resolve erosion mechanisms under controlled conditions. Grid evolution was characterised using a combined diagnostic approach, including scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM–EDX) and micro-computed...     »