Photoionization of atomic systems

Bennaceur Najjari, C Müller, A B Voitkiv

Modifications of photoionization arising from resonant electron–electron correlations between neighbouring atoms in an atomic sample are studied. The sample contains atomic species A and B , with the ionization potential of A being smaller than the energy of a dipole-allowed transition in B . The atoms are subject to an external radiation field which is near resonant with the dipole transition in B . Photoionization of an atom A may thus proceed via a two-step mechanism: photoexcitation in the subsystem of species B , followed by interatomic Coulombic decay. As a basic atomic configuration, we investigate resonant photoionization in a three-atomic system A – B – B consisting of an atom A and two neighbouring atoms B . It is found that, under suitable conditions, the presence of neighbouring atoms can strongly affect the photoionization process, including its total probability, time development and photoelectron spectra. In particular, comparing our results with those for photoionization of an isolated atom A and a two-atomic system A – B , respectively, we reveal the characteristic impact made by the third atom.

James A. R. Samson, Anthony F. Starace

Hannelore E. Saraph

Bennaceur Najjari, Müller, C., Voitkiv, A.

Modifications of photoionization arising from resonant electron-electron correlations between neighbouring atoms in an atomic sample are studied. The sample contains atomic species A and B, with the ionization potential of A being smaller than the energy of a dipole-allowed transition in B. The atoms are subject to an external radiation field which is near-resonant with the dipole transition in B. Photoionization of an atom A may thus proceed via a two-step mechanism: photoexcitation in the subsystem of species B, followed by interatomic Coulombic decay. As a basic atomic configuration, we investigate resonant photoionization in a three-atomic system A-B-B, consisting of an atom A and two neighbouring atoms B. It is found that, under suitable conditions, the influence of the neighbouring atoms can strongly affect the photoionization process, including its total probabilty, time development and photoelectron spectra. In particular, by comparing our results with those for photoionization of an isolated atom A and a two-atomic system A-B, respectively, we reveal the characteristic impact exerted by the third atom.

Alexander B Voitkiv, Bennaceur Najjari

We consider one-photon ionization in a system consisting of two different atoms, $A$ and $B$, which are well separated in space. In such a case, photoionization of the atom with a lower ionization potential can be very strongly influenced, via two-center electron-electron correlations, by resonant electron dipole transitions induced in the other atom. We present a detailed consideration of this resonant photoionization process and discuss a number of effects that are inherent to it.

M. Ya. Amusia