Production of Highly Excited States of Fast Ions Emerging from Solid Targets

Abstract
Production of projectile Rydberg states in fast-ion-foil collisions is shown to exhibit a pronounced target-thickness dependence, proving that Rydberg states are not predominantly formed by direct capture of target electrons. Instead, it is proposed that ionized projectile electrons can undergo transition back to Rydberg states when the ion emerges from the foil.