Abstract
Two-photon double ionization (TPDI) of is studied for -eV photons at the Free Electron Laser in Hamburg (FLASH). Based on model calculations, instantaneous and sequential absorption pathways are identified as separated peaks in the measured fragment kinetic energy release (KER) spectra. The instantaneous process appears at high KER, corresponding to ionization at the molecule’s equilibrium distance, in contrast to sequential ionization mainly leading to low-KER contributions. Measured fragment angular distributions are in good agreement with theory.
- Received 12 August 2009
DOI:https://doi.org/10.1103/PhysRevA.81.021401
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