- Conference date: 28 Sep − 2 Oct 1992
- Location: Manhattan, Kansas (USA)
The production of fast electrons in ion‐atom collisions is a well‐known phenomenon resulting from a binary encounter (BE) between the projectile and the target electron. Recently, it has been demonstrated experimentally that BE electron spectra by heavy structured‐ion impact exhibit a high degree of complexity, including bifurcation of the BE peak at certain emission angles, sudden shift of peak positions within a small angular range, and non‐monotonic change of peak intensity as a function of emission angles.
While theoretical models exist for a qualitative explanation, we focus here on two mechanisms for ionization by structured particle impact, with emphasis on the connection between target ionization in the forward direction by heavy ion impact and projectile ionization on a heavy target at backward angles. One mechanism involves the interaction of the ejected electron on one center with a screened core of the other center. It can be approximated in the independent particle model.
In the other mechanism, the electrons on both centers are simultaneously excited or ionized by explicit electron‐electron interaction (correlation). This process is important when the impact speed is high enough so that the relative kinetic energy between the electrons exceeds the ionization potentials of both centers. A two‐step (second order) process, where the ejected electron collides first with a core electron then with the core nucleus, is examined both quantum‐mechanically and classically. Quantal and classical results for a simple system are in accord with each other.
- Ionization mechanisms
- Collision induced ionization
- Electron correlation calculations
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