Utilisation combinée des deux sources de rayonnements laser et synchrotron : caractéristiques et résultats

Abstract

The first experiments combining the use of cw dye lasers with synchrotron radiation for inner-shell photoionization in laser-excited atoms, were carried out more than 10 years ago. Since that time, a number of resonant inner-shell photoexcitation processes have been measured. The results of these measurements will be summarized. The use of new synchrotron radiation sources such as the third generation storage ring Super ACO in Orsay or the undulator installed at BESSY, in Berlin, enhanced the photon flux available, making feasible new experiments. At high atomic densities, partial photoionization cross sections or angular distribution of inner-electro ns were measured in laser-excited alkali- and alkaline earth atoms, revealing strong enhan­ cements of the intensity of correlation satellites in inner-shell photoionization of excited atoms. At low atomic densities, synchrotron radiation studies of laser-aligned atoms were started, allowing to demonstrate the influence of the laser polarization on the angular distribution of electrons emitted in the decay of core-excited autoionizing states. These new results will be described. Finally, the perspectives open for present and future uses of third generation storage rings in combination with laser(s) will be discussed.