Sequential electron emission and nuclear dissociation after the O 1 s →(Σ-4u)4 p σ excitation in O2 molecules
Abstract
When an electron is resonantly excited from a core orbital to a Rydberg one in a molecule, complex multi-time-scale multistep processes are triggered. By using a high-resolution energy-resolved coincidence between Auger electron and ions, we identified the sequences of processes following the spectator Auger decays induced by K -shell excitation in O2. The first step of the spectator Auger decay can end up to a few metastable O2+ states which autoionize into stable O22 + . However, the majority of O2+ states are dissociative. They evolve into several dissociation limits with complex crossings between potential-energy curves. After the molecular dissociation is finished, the generated fragments can further decay either by fluorescence emission or by autoionization. Interestingly, some electrons are always emitted after molecular dissociation.
- Publication:
-
Physical Review A
- Pub Date:
- February 2019
- DOI:
- 10.1103/PhysRevA.99.022511
- Bibcode:
- 2019PhRvA..99b2511S