Calculated ionization volumes for batch, continuous, and selective extraction sources of heavy ions

Confinement time and ionization volume calculations have been made for batch, diffusive continuous, and selective extraction types of highly ionized, very heavy atom ion sources. For each source, the results are given for step‐by‐step only ionization by an energetic electron flux (1011 e/cm3 at 10 keV) and for ionization which includes the Auger effect. These are compared for loss conditions which vary from no loss to a loss cross section 0.05 times that of the 0 → 1+ionization cross section. For low loss, the ionization volume is least for the selective extraction source, while for a lossy source, the batch process becomes competitive. Volumes for the diffusive continuous source are the largest in all cases. Introduction of the Auger effect reduces the volumes by a factor of 2–10 in all but the diffusive continuous source. The ionization volumes required for an output of one particle microampere of Xe25+ are calculated for the different types of sources.