Many-electron dynamics of atomic processes studied by photon-induced fluorescence spectroscopy

Abstract

The progress and the chronology in understanding the influence of electron correlations on the electronic structure of atoms and the dynamics of atomic processes is reviewed focusing on benchmark rare-gas atoms. The contributions and the chronological development of Photon-Induced Fluorescence Spectroscopy (PIFS), measuring dispersed-fluorescence emission cross sections upon excitation by single photons provided by monochromatized synchrotron radiation is described. Selected experimental results obtained by complementary techniques are also discussed for comparison. The basic suites of computer programs used for the investigation of the many-electron effects in atoms and the obtained results are analyzed. Special attention is paid to the Configuration Interaction Pauli-Fock approximation with Core Polarization (CIPFCP) method used to interpret the PIFS data.

Interatomic and Intermolecular Coulombic Decay

“…This time characteristic enables the in situ comparison of the spectral features of the monomer signal versus cluster signal, that is, apart from spectral shifts between cluster and monomer signal the emission time can be used to distinguish unequivocally the fluorescence emission signal from clusters from the one of the monomers such that condition 1 is fulfilled. For rare gas atoms a variety of absolute values of fluorescence and electron emission cross-sections are known (see review by Sukhorukov et al 380 ) such that for studies on rare gas clusters or mixed clusters with rare gas contributions also condition 2 is fulfilled. To fulfill condition 3, the number of clusters with respect to the number of unclustered monomers has been determined by electron spectrometry using a magnetic bottle spectrometer.…”

Energy-Dependent Relative Cross Sections in Carbon 1s Photoionization: Separation of Direct Shake and Inelastic Scattering Effects in Single Molecules

“…This relatively simple theoretical description of direct shakes is generally reasonable and computationally cost-effective. However, it is incomplete because it does not allow the multielectron excitation effects to be represented, which cannot be described within the one-particle picture and require the consideration of more complex configuration interactions to account for the change in the correlation of the many-electron system. , Further on, we will use “multi-electron correlation satellites” to refer to correlation satellites requiring multiple electron excitations . The probability of multielectron correlation satellites increases with the atomic number Z and already becomes important for atoms possessing 3s electron shells (such as S, Cl, etc.…”

Enhanced polarization transfer to the characteristic $Lα$ x-ray lines near the nonlinear Cooper minimum of two-photon ionization

“…In particular, the photon polarization carries information about the alignment and orientation of an atom, which, in turn, strongly depends on details of the core electron ionization or excitation [13][14][15][16]. The polarization properties of fluorescence light following single photon ionization is a well developed part of atomic spectroscopy [17][18][19][20] in contrast to the nonlinear ionization, which is much less explored. In recent experiments, the total two-photon inner-shell ionization cross sections have been extracted from the subsequent fluorescence yields [8][9][10][11][12].…”