ECRIS for highly charged ions−Present status and new developments (invited)(abstract)

Abstract

There are now approximately 40 electron cyclotron resonance ion sources (ECRIS) for highly charged positive ions, either operating or under construction, worldwide. In recent years, the number of operating sources has been doubling about every three years. The present working level for high performance is now a compact, CW 14-GHz source with high magnetic confinement, simplified microwave injection, and a somewhat suppressed first stage. It has become clear that electron injection into the main stage plasma, from electron guns, biased cathodes, or high secondary electron emission surfaces close to the plasma, raises ion extracted currents, and several efforts are under way to understand this phenomena. Much effort has also been devoted to the production of ions from nongaseous materials, with positive ion beams from approximately half the periodic table now having been produced in ECRIS. The afterglow mode may permit intense short pulse beams of highly charged ions for injection into synchrotrons. Present development efforts are centered on understanding the performance scaling with microwave frequency and magnetic confinement, as well as continued development of intense highly charged ions in existing sources and the development of new metallic species.