Broad Beam Ion Sources for Electrostatic Space Propulsion and Surface Modification Processes: From Roots to Present Applications

Abstract

AbstractIon thrusters or broad beam ion sources are widely used in electrostatic space propulsion and in high‐end surface modification processes. A short historical review of the roots of electric space propulsion is given. In the following, we introduce the electrostatic ion thrusters and broad beam ion sources based on different plasma excitation principles and describe the similarities as well as the differences briefly. Furthermore, an overview on source plasma and ion beam characterisation methods is presented. Apart from that, a beam profile modelling strategy with the help of numerical trajectory codes as basis for a special grid system design is outlined. This modelling represents the basis for the adaptation of a grid system for required technological demands. Examples of model validation demonstrate their reliability. One of the main challenges in improvement of ion beam technologies is the customisation of the ion beam properties, e.g. the ion current density profile for specific demands. Methods of an ex‐situ and in‐situ beam profile control will be demonstrated. Examples for the use of ion beam technologies in space and on earth – the RIT‐10 rescue mission of ESA's satellite Artemis, the RIT‐22 for BepiColombo mission and the deposition of multilayer stacks for EUVL (Extreme Ultra Violet Lithography) mask blank application are provided in order to illustrate the potential of plasma‐based ion beam sources. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)