Ion energy characteristics of a penning ion source

Simultaneous measurements of the energy spectrum of the ion beam and the discharge and the total currents from a Penning ion source have been carried out under various operating conditions. The width of the energy spectrum increases to a maximum in the transition region between the low pressure mode and the high pressure mode and this is believed to be due to instabilities associated with the mode transition. The ionic composition has also been measured for various gases. (author)