Charge states of fast heavy ions in solids — target atomic number dependence

Z₂ (target atomic number) dependence of equilibrium charge states of heavy ions has been investigated for 29 and 59 MeV F, 29-109 MeV Si, 24-109 MeV Cl, and 117 MeV Cu ions after passage through 20 kinds of thin foils with different Z₂. Except for the F ions, mean charge states ītq exhibit oscillations of Z₂ for a given collision energy. Such oscillations are closely related to the Z₂ oscillation of electron capture cross sections into the projectile inner shell vacancies. The relationship of the Z₂dependence of ītq and the stopping power is discussed for heavy ions of a few MeV/u.