Double ionization of atoms and ions |
|
| Stephan Fritzsche | |
| GSI Darmstadt & Oulu University | |
| The sequential two-photon double ionization (TPDI) is one of the simplest non-linear processes in extreme ultraviolet region. Its experimental study became feasible with the advent of the free-electron lasers and has attracted much interest since then. In contrast to the direct (non-sequential) process, which becomes possible only due to electronic correlations, the TPDI proceeds via a well-define intermediate. Despite the sequential absorption of two photons, however, the non-linear interaction between the atoms and the radiation field strongly affects the electron emission as well as the subsequent ionization dynamics, if coupled to the (Auger) continuum of even higher charge states.
In this contribution, I present and discuss some recent work on the direct and sequential (photo-induced) ionization of atoms in the gas phase. |