Ion beam systems

The reactors considered so far consist of a plasma source which is either spatially connected with the processing chamber (DC reactors and CCP reactors) or partially separated as in the high-density reactors, which are spoken of “downstream”reactors. Spatial separation between plasma source and processing chamber leads to ion beam processing which was initially pushed by NASA at the end of the 1950s when they dreamt of interplanetary missions which chould be made feasible with ion thrusters [303, 304]. For optimized thrust, the fuels should combine high atomic weight with low ionization potential to facilitate high ion densities and high a momentum at the same power input. Simultaneously, corrosion should be kept at low a level. Therefore, most experiments were performed with mercury (instead of cesium). This research remained but a dream, but as a typical spin-off process, these systems were identified as plasma sources for inert gas processing.