Berlin 2014 – wissenschaftliches Programm
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A: Fachverband Atomphysik
A 18: Interaction with strong or short laser pulses II
A 18.3: Vortrag
Dienstag, 18. März 2014, 14:45–15:00, BEBEL E34
Controlling the strong-field dissociation of aligned C2H2 ions — •Katharina Doblhoff-Dier1,2, Xinhua Xie2, Markus Kitzler2, and Stefanie Gräfe1 — 1Friedrich Schiller Universität, Jena, Deutschland — 2Technische Universität Wien, Wien, Österreich
Intense, short near infra-red laser sources provide novel tools to control molecular reactions, e.g., via the CE phase[1]. Recently, experimental results have shown the possibility to control fragmentation reactions in acetylene by aligning the molecule relative to the laser polarization direction. In our work, we use these results to gain a better insight into the underlying mechanisms and to obtain an interpretation of the rich experimental results. Simplifying the complex, quantum mechanical dissociation process, we discompose the reaction into several interconnected steps, allowing for their separate modelling and analysis. The complexity of the process, however, requires a wealth of different models. Amongst others, we apply time-dependent density functional theory, molecular tunnelling theory, single orbital electron impact ionization, reduced dimensional quantum dynamics calculations modelling field excitation processes, and both quantum mechanical and (semi-)classical estimates. The comparison and synopsis of all sub-processes allows us to confirm and identify not only multi-orbital contributions but also to investigate the influence of different ionization mechanisms (sequential and non-sequential), relevant for the dissociation process. We hope that the classification of different processes will also help to understand laser aided reactions in more complex molecules.
[1] Xie et al., Phys. Rev. Lett. 109, 243001 (2012)