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

Abstract

Ion 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.

Integration of a broad beam ion source with a high-temperature x-ray diffraction vacuum chamber

“…Schematic presentation of the Faraday cup designed especially for this equipment with the same size and shape as the sample holder thus the ion current density is axially symmetrical and exhibits only a radial dependency. 18 This axial symmetry was achieved in preliminary experiments by in situ adjustment of the position of the ion source in the chamber, as the direction of the ion beam is coincident with the normal of the sample in its centre when the measured ion current has its maximum value. The construction of the ion source and its attachment to the chamber allows changing of the ion beam direction in a well understandable way.…”

Increased Biocompatibility and Bioactivity after Energetic PVD Surface Treatments

“…This extraction and acceleration result in an ion beam with a small diameter, so that a beam steering and target manipulation system are necessary for large and complex shaped samples, increasing the treatment time and the treatment costs. Using broad beam ion sources without mass separation, simultaneous implantation into large flat surfaces is possible [ 56 ].…”

E‐H Transition in Argon/Oxygen Inductively Coupled RF Plasmas

“…ICPs are more recently being used for plasma etching [3][4][5][6][7][8][9][10][11], sterilization and decontamination of sensitive material surfaces [12][13][14], particle generation [15,16], growth of carbon nano tubes [17], polymerization [18], diamond deposition [19,20] surface modification [21] and vapor deposition [22]. Additionally, ICPs are also used in life science [23], for atomic clocks for the global positioning system (GPS) [24] and they are used for thrusters in electric propulsion [25].…”