ON THE RADIATIVE STABILIZATION IN SLOW DOUBLE-ELECTRON CAPTURE COLLISIONS OF HIGHLY CHARGED IONS WITH NEUTRAL ATOMS

We have measured the radiative stabilization probability in double-electron capture collisions for the systems 10 keV u-1 Kr(q+) (q = 13-34) and Ar(q+) (q = 6-17) on Ar, and examined its velocity dependence for Ar8+ on Ar. The measured probability exhibits pronounced structures as a function of q. A model incorporating the initial population, the collision velocity, and the core structure of the incoming projectile is proposed, and the gross features are fairly accounted for. The results support the importance of populating asymmetric Rydberg states and reveal the crucial role played by the projectile core structure. The velocity dependence measurements favour a post-collision interaction mechanism for the population of the asymmetric Rydberg states, such as that proposed by Bachau et al.