The method of 0°Auger spectroscopy was applied to measure state-selective K-shell excitation in Li-like Ne7+ incident with 170 MeV on H2, He, CH4, Ne, and Ar. The high-resolution technique allows for the separate analysis of the states a2P and b2P whose dominant components are 1s(2s2p 3P)2P and 1s(2s2p 1P)2P, respectively. The results are used to study time-ordering and interference effects in the process of single excitation. For the state 1s(2s2p 3P)2P it is found that the phenomenon of Pauli blocking inhibits the loss of time ordering, whereas dealignment effects diminish interferences between first- and second-order mechanisms. The 1s(2s2p 1P)2P state involves partial loss of time ordering; however, non-spin-flip rules recover sufficient time ordering so that interference effects can be observed. The semiclassical approximation is used up to second order to provide conclusive evidence for the measured interference effects.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics