| 1. |
- Feifel, Raimund, et al.
(författare)
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Cationic double K-hole pre-edge states of CS2 and SF6
- 2017
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in X-ray instrumentation have made it possible to measure the spectra of an essentially unexplored class of electronic states associated with double inner-shell vacancies. Using the technique of single electron spectroscopy, spectra of states in CS2 and SF6 with a double hole in the K-shell and one electron exited to a normally unoccupied orbital have been obtained. The spectra are interpreted with the aid of a high-level theoretical model giving excellent agreement with the experiment. The results shed new light on the important distinction between direct and conjugate shake-up in a molecular context. In particular, systematic similarities and di erences between pre-edge states near single core holes investigated in X-ray absorption spectra and the corresponding states near double core holes studied here are brought out.
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| 2. |
- Goldsztejn, G., et al.
(författare)
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Electronic-state-lifetime interference in the hard-x-ray regime : Argon as a showcase
- 2017
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Ingår i: PHYSICAL REVIEW A. - : AMER PHYSICAL SOC. - 2469-9926. ; 95:1
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Tidskriftsartikel (refereegranskat)abstract
- Electronic-state-lifetime interference is a phenomenon specific for ionization of atoms and molecules in the hard-x-ray regime. Using resonant KL2,3L2,3 Auger decay in argon as a showcase, we present a model that allows extracting the interference terms directly from the cross sections of the final electronic states. The analysis provides fundamental information on the excitation and decay processes such as probabilities of various decay paths and the values of the dipole matrix elements for transitions to the excited states. Our results shed light on the interplay between spectator, shake-down, and shake-up processes in the relaxation of deep core-hole states.
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| 3. |
- Goldsztejn, G., 2017, et al.
(författare)
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Experimental and theoretical study of the double-core-hole hypersatellite Auger spectrum of Ne
- 2017
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Ingår i: Physical Review A. - : AMER PHYSICAL SOC. - 2469-9926 .- 2469-9934. ; 96
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Tidskriftsartikel (refereegranskat)abstract
- We present the hypersatellite Auger spectrum of neon which contains the decay transitions of the K−2, K−2V, K−2L−1, K−2L−1V, and K−1L−1V states. The Auger decays of these types of core-hole states show different line shapes and linewidths which can be distinguished due to the high experimental resolution available for the present experiments. The individual Auger transitions are assigned based on various approaches. Complementary calculations are performed to assign the K−2L−1 → K−1L−3 and the K−2L−1V → K−1L−3V Auger transitions. Based on the obtained results we were able to derive the ratio for the double to single ionization yield.
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| 4. |
- Kukk, E., et al.
(författare)
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Photoelectron recoil in CO in the x-ray region up to 7 keV
- 2017
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Ingår i: PHYSICAL REVIEW A. - 2469-9926. ; 95:4
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Tidskriftsartikel (refereegranskat)abstract
- Carbon 1s photoelectron spectra of CO molecules in gas phase were recorded in the tender x-ray energy range, from 2.3 to 6.9 keV. The intensity ratios of individual peaks from nu = 0 to 3 within the vibrational progression of the C 1s photoelectron spectrum were determined at the various photon energies and are shown to be strongly affected by the photoelectron recoil effect. The experimental vibrational intensity ratios are compared with theoretical predictions at different levels of accuracy. Developments of the recoil model, using generalized Franck-Condon factors, rovibrational coupling, Morse potential energy curves, and accurate angular averaging are presented and applied to the analysis of the experimental results.
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| 5. |
- Marchenko, T., et al.
(författare)
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Potential Energy Surface Reconstruction and Lifetime Determination of Molecular Double-Core-Hole States in the Hard X-Ray Regime
- 2017
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 119:13
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Tidskriftsartikel (refereegranskat)abstract
- A combination of resonant inelastic x-ray scattering and resonant Auger spectroscopy provides complementary information on the dynamic response of resonantly excited molecules. This is exemplified for CH3I, for which we reconstruct the potential energy surface of the dissociative I 3d(-2) double-core-hole state and determine its lifetime. The proposed method holds a strong potential for monitoring the hard x-ray induced electron and nuclear dynamic response of core-excited molecules containing heavy elements, where ab initio calculations of potential energy surfaces and lifetimes remain challenging.
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| 6. |
- Piancastelli, Maria Novella, et al.
(författare)
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New achievements on relaxation dynamics of atoms and molecules photoexcited in the tender x-ray domain at synchrotron SOLEIL
- 2017
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 50:4
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Forskningsöversikt (refereegranskat)abstract
- The so-called 'tender' x-ray domain, from 2 to 13 keV, has recently become available for atomic and molecular studies at the French synchrotron SOLEIL with state-of-the-art photon and electron energy resolution. We investigated a wealth of new phenomena by means of photoelectron and Auger spectroscopy and electron-ion coincidence techniques. The list includes recoil due to the photoelectron's momentum, ultrafast nuclear motion on the femto-and sub-femtosecond time scale, double-core-hole studies, electron recapture effects, exotic Auger decay pathways, deep-edge molecular-frame photoelectron angular distribution studies, and core-hole localization/delocalization phenomena for deep-core vacancies. We demonstrate that the newly accessible extended photon energy range does not simply allow studying more systems with deeper core edges, but opens a totally new horizon in what concerns electron and nuclear dynamics of deep-core-excited and core-ionized isolated species.
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| 7. |
- Puettner, R., et al.
(författare)
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Detailed assignment of normal and resonant Auger spectra of Xe near the L edges
- 2017
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Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - 2469-9926 .- 2469-9934. ; 96:2
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive experimental and theoretical investigation on the LMM, LMN, and LNN normal Auger spectra of xenon, which reveal excellent agreement with theory when core-hole lifetimes of the two-hole final states are taken into account. Generally, the spectra turned out to be highly complex due to a strong overlap of the Auger transitions subsequent to 2s(1/2)(-1), 2p(1/2)(-1), and 2p(3/2)(-1) ionization. This overlap is due to the splitting of the three initial L core holes and the different final M and N core holes being on the same order of magnitude of several hundred eV. The Auger transitions are assigned in detail based on the theoretical results. Most of the MM, MN, and NN final states are described well based on jj coupling. In addition, we present a detailed assignment of the resonant LM45M45 Auger transition subsequent to the 2s -> 6p, 7p and 2p -> 5d, 6d excitations.
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| 8. |
- Travnikova, O., et al.
(författare)
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Subfemtosecond Control of Molecular Fragmentation by Hard X-Ray Photons
- 2017
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Ingår i: Physical Review Letters. - : AMER PHYSICAL SOC. - 0031-9007 .- 1079-7114. ; 118:21
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Tidskriftsartikel (refereegranskat)abstract
- Tuning hard x-ray excitation energy along Cl 1s -> sigma* resonance in gaseous HCl allows manipulating molecular fragmentation in the course of the induced multistep ultrafast dissociation. The observations are supported by theoretical modeling, which shows a strong interplay between the topology of the potential energy curves, involved in the Auger cascades, and the so-called core-hole clock, which determines the time spent by the system in the very first step. The asymmetric profile of the fragmentation ratios reflects different dynamics of nuclear wave packets dependent on the photon energy.
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