Hannover 2013 – scientific programme
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MO: Fachverband Molekülphysik
MO 29: Collisions and Energy Transfer
MO 29.4: Talk
Friday, March 22, 2013, 11:45–12:00, F 107
Coulomb Explosion Imaging of the metastable anion D2− — •P. Herwig1, M. Grieser1, R. Repnow1, R. Golser2, M. Cizek3, D. Schwalm1,4, A. Wolf1, and H. Kreckel1 — 1Max-Planck Institut für Kernphysik, Heidelberg — 2VERA Laboratory, Universität Wien — 3Institute of Theoretical Physics, Charles University Prague, Czech Republic — 4Weizmann Institute of Science, Rehovot., Israel
The negative hydrogen molecular ions H2− and D2− have been challenging theory for more than 50 years. Modern calculations predict these simple anions to be metastable when rotating strongly, with lifetimes ranging from microseconds to milliseconds. While the calculated wave functions of H2− were verified by Coulomb Explosion Imaging (CEI) [1], a photoionization experiment of D2− showed a deviation between theory and experiment [2]. To investigate this discrepancy we have performed a new CEI in 2012 with metastable D2−. The D2− ions are produced in a duoplasmatron ion source, accelerated to a kinetic energy of 1.92 MeV and directed at a diamond like carbon foil. Here the electrons are stripped off within 100 as and the Coulomb explosion is triggered. A 3D detector measures the velocity distribution of the fragments which yields a mirror image of the molecular wave function. A Monte Carlo Simulation of the explosion process is used to compare the experimental results to calculated wave functions.
[1] B.J. Thaden et al., PRL 107, 193003 (2011)
[2] L. Lammich et al., PRA 80, 023413 (2009)