A Potential Parameter on the Stabilization Ratio of Double-electron Transfer in Slow Highly Charged Ions with Helium Collisions

Key words: 
• double-electron transfer /
• true double capture /
• autoionizing double capture /
• stabilization

Abstract: We borrow the concept of virtual state to characterize the strong interacting feature of the two transferred electrons in slow highly charged ions with helium collisions. Consequently, a potential parameter ! is de ned to distinguish the collision systems and to scale the double-electron transfer processes. The Q-value is taken into account according to the classical over-the-barrier model. Comparing with our previous experimental data, it is clearly shown that the true double capture or the autoionizing double capture dominates when ω>1 or ω> 2, respectively. We clarify that the distinction of the collision systems is essentially the ratio between the average excitation energy and the average binding energy of the two transferred electrons at the scattered ion.