Target Thickness Dependence of K X-Ray Production for 55 MeV BR Ions in GE

A large target thickness variation is observed in K x-ray cross sections for 55 MeV Br ions on thin solid Ge targets. An excellent description of the data is obtained using a two component model for the beam traveling through the target. The excited beam component (presumably a 2p vacancy) created in a previous collision has an enhanced cross section for K x-ray production compared to the normal beam with no inner shell vacancies. The enhancement factor is determined to be 5.4. At equilibrium the yield of K x-rays from the two collision process is 4.0 times as large as the yield from the single collision process.