  The K x-ray spectra of different targets (Cu, Zn, and Ge) induced by 3 to 5
MeV/u Si projectile ions have been measured to determine the K-shell ionization
cross-section. A significant difference is observed between the measurements
and theoretical estimates, where the theoretical ones are about 28-35% of the
experimental results. Such difference is reduced to a good extent 51-56% if
multiple ionization effects are taken into account. Remaining discrepancy may
be attributed to the electron capture contribution.
