Abstract
We report on an experimental and theoretical systematic study of double ionization of helium by ion impact in terms of four-particle Dalitz plots. Several collision systems covering a broad range of perturbation parameters η (projectile charge to speed ratio) were investigated. With increasing η we observe a systematic trend from features, characteristic to correlated double-ionization mechanisms, to signatures of higher-order processes not requiring electron-electron correlations [the mechanism called "two-step-two projectile-electron interaction" (TS-2)]. The data for the largest η can qualitatively be amazingly well described by a simple model only including the TS-2 mechanism.
Original language | English |
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Article number | 062703 |
Journal | Physical Review A - Atomic, Molecular, and Optical Physics |
Volume | 80 |
Issue number | 6 |
DOIs | |
State | Published - 3 Dec 2009 |
Externally published | Yes |