Charge state distributions for heavy ions in carbon stripper foils

The authors have extended the database of measured charge state distributions available in the literature through measurements at the SuperHILAC using carbon stripper foils in the energy range 1.2-8.5 MeV/u. By modifying a semiempirical model to include the effect of electronic shells, they are able to correctly predict the mean charge state to within 1/2 a charge state for 6 ≤ Z ≤ 92 and energies from 30 keV/u to 16 MeV/u. Parameters for the widths of the distributions were determined for each electronic shell. For distributions lying across a shell boundary, two Gaussians of different widths were joined to get an asymmetric distribution. Using these modifications, the codes used at the Bevalac for predicting charge state distributions were improved.