Stuttgart 2012 – scientific programme
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MO: Fachverband Molekülphysik
MO 16: Collisions and Spectroscopy in He-Droplets
MO 16.3: Talk
Thursday, March 15, 2012, 11:00–11:15, V38.02
Transfer ionization in swift D+ on H2 collisions - dependence of the electron emission on the internuclear distance — •Markus Waitz, Hong-Keun Kim, Jasmin Titze, Markus S. Schöffler, Till Jahnke, Achim Czasch, Lothar Ph. H. Schmidt, Horst Schmidt-Böcking, and Reinhard Dörner — Institut für Kernphysik, Goethe-Universität Frankfurt, 60438 Frankfurt, Germany
Transfer ionization in swift (several a.u. velocity) ion helium collisions leads to a rich structure in the momentum distribution of the emitted electron. One part of the electrons is emitted in the forward direction, similar to single ionization. This might be associated with a two step process, where two independent interactions of the projectile with either electron leads to capture of one and ionization of the second one. There is however also a strong distinct peak of backward emitted electrons. The underlying mechanism is single capture accompanied by a shake off of the second electron. Here we report on the first experimental observation of transfer ionization on molecular hydrogen. The momentum distribution of the measured electron shows a clear subdivision into forward and backward emission. In addition, we find a surprising dependence of electron emission on the internuclear distance. The forward part of the electron momentum distribution gives higher values for perpendicular orientation of the molecule with respect to the incident beam direction. The SO part does not show this dependence. As a result, the ratio between forward and backward emission changes with internuclear distance.