Ion extraction characteristics on a barium plasma produced between grounded parallel plate electrodes and a positively biased upper plate electrode

When a barium plasma was suddenly produced between parallel plate electrodes and an upper plate electrode with a higher potential, the ion extraction was investigated in comparison with characteristics of the usual parallel plate electrode configuration. The parameter dependencies of ion extraction time by an external electric field, measured under a variety of experimental conditions, led to the conclusion that the ion extraction time can be expressed as the product of exponents of the applied voltage, plasma width, and ion density as well as the parallel plate electrodes. This scaling relation estimates the ion extraction time with an accuracy of 15% for a given parameter set. Comparison of the scaling relations for the new electrode concept with a highly biased upper plate electrode and the parallel plate electrodes showed that the former improves the ion extraction time by a maximum factor of 2.6.