Atomic MagnetoDipole Photoionization

Volker Wippel, C. Binder, W. Huber +4 more

Summary form only given. Photoionization of cold atoms in their first excited state has been applied to measure the photoionization cross section in rubidium magneto-optical trap (MOT), and cesium MOT. The modifications of the MOT loading rate and of the steady state number of trapped atoms allow one to measure the dependence of the cold atom photoionization cross section on the laser wavelength for absorption from the excited atomic state. We report here on measurements of photoionization cross-sections of both laser-cooled sodium and lithium atoms at various photoionization wavelengths.

Hannelore E. Saraph

Philip George Burke

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.

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