| 1. |
- Hult Roos, Andreas, et al.
(författare)
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Abundance of molecular triple ionization by double Auger decay
- 2018
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Systematic measurements of electron emission following formation of single 1s or 2p core holes in molecules with C, O, F, Si, S and Cl atoms show that overall triple ionization can make up as much as 20% of the decay. The proportion of triple ionization is observed to follow a linear trend correlated to the number of available valence electrons on the atom bearing the initial core hole and on closest neighbouring atoms, where the interatomic distance is assumed to play a large role. The amounts of triple ionization (double Auger decay) after 1s or 2p core hole formation follow the same linear trend, which indicates that the hole identity is not a crucial determining factor in the number of electrons emitted. The observed linear trend for the percentage of double Auger decay follows a predictive line equation of the form DA = 0.415 · Nve + 5.46.
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| 2. |
- Hult Roos, Andreas, et al.
(författare)
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Dissociations of water ions after valence and inner-valence ionization
- 2018
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 149
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Tidskriftsartikel (refereegranskat)abstract
- Energy selected and mass‐resolved electron‐ion coincidence spectra of heavy water have been recorded for ionization energies from 18 to 35 eV. Dissociation from the B2B2 state produces both O+ and D2+ at energies near their thermodynamic thresholds in addition to the known products D+ and OD+. Relative yields of O+, OD+ and D+ in the B2B2 state breakdown diagram are modulated by the vibrational structure of the B‐state population, implying incomplete energy equilibration before fragmentation. Decay from the C‐state produces OD+ in addition to the known O+ and D+. The fragment kinetic energies suggest that O+ and D+ from the C state are products of full atomization of the molecule.
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| 3. |
- Squibb, Richard J., et al.
(författare)
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Acetylacetone photodynamics at a seeded free-electron laser
- 2018
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Thefirst steps in photochemical processes, such as photosynthesis or animal vision, involvechanges in electronic and geometric structure on extremely short time scales. Time-resolvedphotoelectron spectroscopy is a natural way to measure such changes, but has been hinderedhitherto by limitations of available pulsed light sources in the vacuum-ultraviolet and soft X-ray spectral region, which have insufficient resolution in time and energy simultaneously. Theunique combination of intensity, energy resolution, and femtosecond pulse duration of theFERMI-seeded free-electron laser can now provide exceptionally detailed information onphotoexcitation–deexcitation and fragmentation in pump-probe experiments on the 50-femtosecond time scale. For the prototypical system acetylacetone we report here electronspectra measured as a function of time delay with enough spectral and time resolution tofollow several photoexcited species through well-characterized individual steps, interpretedusing state-of-the-art static and dynamics calculations. These results open the way forinvestigations of photochemical processes in unprecedented detail.
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