Selection and Primary Focusing of Ions in a Source of Multidischarge Ions

摘要

A report is given on the effective use of plasma focusing when selecting ions from a pulse source of multiply charged ions (pulse length 200 micro sec., repetition rate 2 cps). Gaseous nitrogen was admitted into the source. With optimum selection of the parameters of discharge in the source, potential of the extracting electrode and the geometry of the source gap, the extracting electrode received a 300 ma pulse current of heavy ions accelerated to 35 kv. Half of this current consists of nitrogen ions, the balance of ions of elements making up the material from which the ion source is constructed. The presence of N(+3) - 17 ma, N(+2) - 54 ma, N(+) - 42 ma, F(+2) - 30 ma, F(+2) - 20 ma etc. ions was established in the spectrum. (Author)