After core ionization of an atom or molecule by an x-ray photon, multiply charged ions are produced in the Auger decay process. These ions tend to neutralize their charge when embedded in an ...environment. We demonstrate that, depending on the atom or molecule and its neighbors, electron transfer mediated decay (ETMD) provides a particularly efficient neutralization pathway for the majority of the ions produced by Auger decay. The mechanism is rather general. As a showcase example, we conducted an ab initio study of the NeKr2 cluster after core ionization of the Ne atom. This example has been chosen because it is amenable to both ab initio calculations and coincidence experiments. We find that even for frozen nuclei, the neutralization rate can be as fast as 0.130 ps(-1). We also show that nuclear dynamics may increase the rate by about an order of magnitude. The generality of the mechanism makes this neutralization pathway important in weakly bonded environments.
We introduce and present a theory of interferometric measurement of a normal Auger decay lifetime in molecules. Molecular Auger interferometry is based on the coherent phase control of Auger dynamics ...in a two-color (ω/2ω) laser field. We show that, in contrast to atoms, in oriented molecules of certain point groups the relative ω/2ω phase modulates the total ionization yield. A simple analytical formula is derived for the extraction of the lifetimes of Auger-active states from a molecular Auger interferogram, circumventing the need in either high-resolution or attosecond spectroscopy. We demonstrate the principle of the interferometric Auger lifetime measurement using inner-valence decay in CH_{3}F.
Molecular Auger Interferometry Khokhlova, M; Cooper, B; Ueda, K ...
Journal of physics. Conference series,
01/2020, Letnik:
1412, Številka:
13
Journal Article
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Synopsis We propose a theory of interferometric measurement of a normal Auger decay width in molecules. Molecular Auger interferometry is based on the coherent phase control of Auger dynamics in a ...two-colour (ω/2ω) laser field. We show that, in contrast to atoms, in oriented molecules of certain point groups (e.g. CH3F) the relative ω/2ω phase modulates the total ionisation yield. A simple analytical formula is derived for the extraction of the widths of Auger-active states from a molecular Auger interferogram, avoiding the need of either attosecond or high-resolution spectroscopy.
Synopsis We report on experimental and theoretical study of collective Auger decay of double inner-valence vacancy in fluoromethane, in which two electrons simultaneously fill the vacancies and a ...third electron is ejected to continuum. Calculations predict the respective lifetime of the double vacancy state to be in the femtosecond range, typical for two-electron Auger decay. Measured electron spectra indirectly support this rather surprising result.
Since their theoretical prediction in 1997, interatomic (intermolecular) Coulombic decay (ICD) and related processes have been in the focus of intensive theoretical and experimental research. The ...spectacular progress in this direction has been stimulated both by the fundamental importance of the discovered electronic decay phenomena and by the exciting possibility of their practical application, for example in spectroscopy of interfaces. Interatomic decay phenomena take place in inner-shell-ionized clusters due to electronic correlation between two or more cluster constituents. These processes lead to the decay of inner-shell vacancies by electron emission and often also to disintegration of the resulting multiply ionized cluster. Here we review the recent progress in the study of interatomic decay phenomena in singly and multiply ionized clusters.
We present an improved nonlocal resonance model for electron-HCl collisions. The short-range part of the model is based on ab-initio electron scattering eigenphase sums calculated using the Schwinger ...Multichannel method and the long-range part on the potential curve of the bound HCl− anion. We have calculated cross sections for vibrational excitation and dissociative electron attachment. For all collision processes where quantitative experimental data are available, the new model agrees with experiments better than the previous model.
In this work we present a comprehensive and detailed study of Interatomic Coulombic Decay (ICD) occurring after irradiating argon dimers with XUV-synchrotron radiation. A manifold of different decay ...channels is observed and the corresponding initial and final states are assigned. Additionally, the effect of nuclear dynamics on the ICD electron spectrum is examined for one specific decay channel. The internuclear distance-dependent width Γ(R) of the decay is obtained from the measured kinetic energy release distribution of the ions employing a classical nuclear dynamics model.
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