Neutralised low energy ion beam generator, method of producing a neutralised low energy ion beam and method of producing a neutralised high energy ion beam

摘要

A neutralised low energy ion beam is produced by forming a plasma between an anode (13) and a cathode (14) and maintaining a grid (16) at a potential slightly more positive than the cathode (14) so that a beam containing positive ions and high energy primary electrons from the plasma passes through the grid (16).;A neutralised high energy ion beam is produced by directing (Fig. 4) a low energy beam containing charged particles of opposite polarity to that of the ions in an unneu- trallsed high energy ion beam across the latter beam. The low energy beam may be one produced by a generator Fig.1) as described above or another ion source and an electron source (21).