On the role of transfer excitation in slow Xeq+-He,Xe (15 < or = q < or = 42) collisions

The authors have measured cross sections for single-electron capture, true double-electron capture and transfer ionization in slow (0.1-0.2 au) collisions of Xe q+ (15 < or = q < or = 42) with He and Xe targets. The ratio of two- and one-electron removal from Xe is about twice of that from He for high q. This difference is accounted for quantitatively by assuming an independent-electron transfer-excitation mechanism, which turns out to be effective for two- but not for multiple-electron targets.