Düsseldorf 2007 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 18: Interaction with VUV and X-Ray light
A 18.3: Vortrag
Mittwoch, 21. März 2007, 17:15–17:30, 6G
Investigation of the fragmentation processes in rare gas cluster with a reaction microscope — •Matthias Hoener1, Christioph Bostedt1, Lutz Foucar2, Heiko Thomas1, and Thomas Möller1 — 1Institut für Optik und Atomare Physik, TU Berlin — 2Institut für Kernphysik, Universität Frankfurt
The investigation of ioniziation and fragmentation processes with reaction microscopes based on the Coltrims (cold target recoil ion momentum spectrsoscopy) technique has developed into a vivid field of research in atomic physics. We have applied the momentum resolving Coltrims technique to study the fragmentation dynamics of clusters. The clusters were excited with 80 and 700eV photons. This way different numbers of average charges, 3 and 7 respectively, can be generated on the cluster. The ionic fragments from the reaction were measured in coincidence with the photoelectrons. Depending on the photon energy and thus number on charges the reaction-patterns look significantly different. For small cluster irradiated with 700eV photons the monomers, i.e., singly charged Xe-atoms are the dominant fragments. They exhibit a significant amount of momentum, which they gained during the coulombic repulsion with the other ionic cluster atoms. In contrast, large cluster irradiated by 80eV photons behave completely different. The reduced number of ions in the large cluster leads only to fission into large fragments. The observations that multicharged cluster explode and singly charged cluster break, are consistent with theoretical predictions. We thank the group of H. Schmidt-Böcking and R. Dörner from the Universität Frankfurt for their support.