| Autor: |
Sass, C. S., Rabalais, J. W. |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 9/15/1988, Vol. 89 Issue 6, p3870, 7p |
| Abstrakt: |
Scattering of molecular nitrogen ions in the 1.5–4.5 keV range from gold and graphite surfaces results in a small fraction of surviving molecules and molecular ions in addition to atoms and atomic ions resulting from dissociation. The kinetic energy (Ek ) distributions of scattered N+2 and N+ ions have been measured directly by means of an electrostatic sector analyzer (ESA) and the velocity distributions of the scattered N2 and N neutrals plus ions have been measured by time-of-flight (TOF) techniques. Scattered ion fractions were determined from the TOF measurements. The relative Ek distributions of the scattered atomic ions indicate that dissociation from excited repulsive electronic states which are populated during the collision dominate the mechanism, rather than purely vibrational or rotational excitation from the X 2Σ+g ground state of N+2 . The excited dissociative C 2Σ+u and D 2Πu states of N+2 are accessible by Franck–Condon transitions from the X2Σ+g state. The data are consistent with a mechanism in which these two dissociative states contribute their repulsive energy to the large relative Ek distributions of the scattered N+ ions. The electronic excitation occurs via electron promotion during the scattering collision through the Fano–Lichten mechanism. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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