Berlin 2001 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MO: Molekülphysik
MO 8: Posters Thursday: Dissociation and other Collision Processes
MO 8.18: Poster
Thursday, April 5, 2001, 12:30–15:00, AT3
Dissociative Charge Transfer from Na Rydberg Atoms to Vibrationally Excited Na2 Molecules and the Perspectives of field-free imaging — •O. Kaufmann1, A. Ekers1,2, and Klaas Bergmann1 — 1Fachbereich Physik der Universität Kaiserslautern, Postfach 3049, D-67653 Kaiserslautern — 2University of Latvia, Institute of Atomic Physics and Spectroscopy, Raina bulv. 19, LV-1586 Riga, Latvia
We report the observation of the vibrational dependence of dissociative charge transfer (DCT), Na2(X1Σg+, v″) + Na**(nl) → Na− + Na + Na+, in a single Na/Na2 supersonic beam at low intra-beam collision energies (1.6 meV) using the STIRAP technique for selective vibrational excitation of Na2 in the electronic ground state and time-of-flight mass analysis of the ions. The efficiency of this process increases by about an order of magnitude in the range 13 ≤ v″ ≤ 22. Some perspectives are discussed regarding the implementation of a field-free ion-imaging technique for the detection of ions, that will allow the direct determination of the kinetic energy distributions of product negative ions and thus to distinguish among different possible mechanisms of the DCT process. The results of test experiments on imaging of photodissociation products of Na2(v″) without an extraction field are presented confirming the potential of the new detection concept.