Experimental evidence for projectile electronic structure effects in slow multielectron capture collisions

Abstract

We investigate the role of the electronic structure of the projectile in collisional ionization and fragmentation of CO2 via multielectron capture at 0.31 a.u. impact velocity. Focusing on the CO3+2→O+:C+:O+ break-up channel as a representative channel, we report kinetic energy release distributions (KERDs) for collisions with equivelocity N𝑞+ and O𝑞+ projectiles. We consider two complementary categories of measurements. In the first category, in which different projectiles of the same charge are considered, we find that KERDs obtained with N𝑞+ and O𝑞+ impact (𝑞=4,6) are broadly similar, but they differ significantly from the earlier reported KERD with Ar𝑞+ impact. In the second category, pronounced differences are observed between the KERDs obtained with isoelectronic N𝑞+ and O(𝑞+1)+ (𝑞=3,5,7) projectiles. These results provide clear evidence that projectile electronic structure plays a critical role in multielectron capture collisions.