New Frontiers in Atomic, Molecular and Optical Physics at VUV or Soft X-Ray FELs
Joachim Ullrich
Max-Planck-Institut für Kernphysik, Heidelberg
Upcoming 4th generation lights sources, Free Electron Lasers (FEL), will provide, for the first time, intensities, coherence properties, short-time and pump-probe options in the VUV to X-ray regime comparable to those presently realized by intense, ultra-short laser pulses in the visible. At least three completely new fields of research are expected to open up in atomic and molecular physics. First, the huge integrated radiation flux enables to investigate in unprecedented detail dilute samples, as for example positive ions up to the highest charge states, negative atomic ions, negative or positive state-prepared molecular and size-selected cluster ions. Second, the tremendous peak intensities allow investigating, for the first time, fundamental non-linear processes where few photons interact with few electrons in atoms, molecules, clusters or ions. Third, the short-time properties will enable unique pump-probe experiments with any of these targets. In the talk, these novel fields will be highlighted and first results of pioneer experiments at the Free Electron Laser at Hamburg (FLASH) will be discussed in some detail. Future possibilities on ultra-fast pump-probe experiments, Coulomb-explosion imaging, the investigation of strongly correlated plasmas, etc. will be envisioned.
