New Method of Large-Area DC Ion Beam Formation with Multiple Electron Beams, (I)Effect of Ion Density Distribution of Source Plasma on Geometrical Shape of Plasma Boundary

摘要

A study was made of the correlation between the focusing of an ion beam and thespatial distribution of the ion density in the source plasma, which determines thegeometrical shape of the plasma boundary, using a duoplasmatron ion source. It wasrevealed that the focusing of the ion beams extracted from a gaseous plasma through alarge-area single aperture is sensitively influenced by the concavity of the plasmaboundary, which concavity varies with the radial density profile of the plasma ions atthe plasma boundary.