Multiple Electron Capture by 46 MeV/u Pb81+ Ions from Solid Targets

Significant multiple electron capture has been found in collisions of 46 MeV/u Pb81+ ions with thin carbon foils. An increase in the many-electron capture probability has been observed for the thinnest targets, which is contrary to the normally assumed process of subsequent single-electron capture in the bulk. This shows the significant contribution of the surface for multiple electron capture. Further evidence is found for a strongly reduced capture probability from the exit surface as compared to the entrance surface. Absolute yields for electron capture and projectile ionization are presented and discussed within a Monte-Carlo simulation.