Grid erosion is a dominating factor limiting the lifetime of gridded ion thrusters. Erosion is mainly driven by charge exchange processes between ions and neutrals of the operating gas (propellant), resulting in a species of slow ions, which have trajectories that do not follow the ion optics design and lead to sputtering of the grid surface by ion impingement. Within this project, neutral densities of xenon and krypton, and of eroded species such as carbon or molybdenum are measured specifically within the inter-grid and near the exit plane of a gridded ion thruster using laserspectroscopic methods. The inter-grid area is identified with the main region from where charge exchange processes contribute to the ion thruster accelerator grid erosion. Besides ion thrusters, the data may be also important for numerical modeling of ion sources in terrestrial applications.

Duration: 2021 – 2024
Funding: 321.659,27 Euro
Funding programme: Bundesministerium für Wirtschaft und Energie (BMWi)