ELECTRON-EMISSION DURING MULTICHARGED ION-SURFACE INTERACTIONS

[摘要] Recent measurements of electron spectra for slow multicharged N ion-surface collisions are presented. The emphasis is on potential emission, i.e., the electron emission related to the neutralization of the ions. When using N ions that carry a K shell vacancy into the collision, characteristic K Auger electron emission from the projectiles is observed as well as, for specific surfaces, target atom Auger transitions (resulting from vacancy transfer). Measurements of the intensity of these Auger transitions as a function of the time the ions spend above the surface can serve as a useful probe of the timescales characterizing the relevant neutralization processes. This technique is elucidated with the help of some computer simulations. It is shown that neutralization timescales required in the atomic ladder picture, in which neutralization takes place by resonant capture followed by purely intra-atomic Auger transitions, are too long to explain our experimental results. The introduction of additional neutralization/de-excitation mechanisms in the simulations leads to much better agreement with the experiments.

[发布日期] 1991-05-01

[效力级别]  Proceedings Paper