Systematic investigation of a magnetic ion source for an electromagnetic isotope separator

Abstract

The properties of a magnetic ion source with oscillating electrons are studied. The ion source is operated in connection with an electromagnetic isotope separator. Special interest is devoted to the obtainable ion currents, the resolving power of the instrument, and the efficiency of the ion source. The ion current and the resolving power can be varied within wide limits. However, if the ion source is operated at conditions corresponding to maximum resolving power, it is found that the ion current is limited by space charge in the ion extracting device. By measurements of the parameters of the ion source, performed at maximum resolving power, an investigation of the plasma discharge was possible. It was found that, for maximum resolving power, a constant ion production rate was required, determined only by the extracted ion current. Applying this result the influence of different factors on the efficiency of the ion source was calculated. The efficiency appeared to be proportional to the length of the discharge chamber and to the ionization cross section. This was also verified experimentally. Gothenburg.