Equilibrium charge distributions have been measured for 18 kinds of ions passing through a carbon foil in the energy region of 1–6 MeV/u for light ions and of 0.2–1 MeV/u for heavy ions. By combining the data obtained at present with those reported for other energies or ion species, an attempt is made to find the systematics for charge fraction F(q), mean charge q¯, and distribution width d over the wide range of ion species Z and energy E. Strong correlation has been found between the shell structure of ions and the variation of q¯ or d with Z or E. The analysis for this correlation enables the evaluation of rather reliable values of q¯, d, or F(q) for ion species 4≤Z≤92 in carbon foils from 0.02 to 6 MeV/u.

• Received 10 April 1989

DOI:https://doi.org/10.1103/PhysRevA.40.3557