Many-particle fragmentation processes in atomic and molecular physics. New insight into the world of correlation

Full text: Correlated many-particle dynamics in Coulombic systems, which is one of the unsolved fundamental problems in AMO-physics, can now be experimentally approached with so far unprecedented completeness and precision. The recent development of the COLTRIMS technique (COLd Target Recoil Ion Momentum Spectroscopy) provides a coincident multifragment imaging technique for eV and sub-eV fragment detection. In its completeness it is as powerful as the bubble chamber in high energy physics. In recent benchmark experiments quasi snapshots (duration as short an atto-sec) of the correlated dynamics between electrons and nuclei has been made for atomic and molecular objects. This new imaging technique has opened a powerful observation window into the hidden world of many-particle dynamics. The principle of the new reaction microscope (synonym: COLTRIMS) will be presented. If imaging detectors based on fast delay-line position read-out are used multi-hit detection is possible. Even two particles hitting the detector at the 'same' instant (Δt < 1 ns) can simultaneously be detected. The number of detected multi-hits is practically only limited by the electronics needed to store in event mode all information. Several examples for COLTRIMS data will be shown: double excitation and ionization of He as well as complete differential data in momentum space for many particle fragmentation of molecules by ions and photons. The obtained information on e-e correlation is discussed