Wed, 30.10.2019  |  10:00
Seminar Room A, 2.01

Monochromized HHG pump NIR probe experiments of Methyl Iodide

Marta Murillo Sánchez | Complutense University of Madrid, Spain

talks about

Ultrashort extreme ultraviolet (XUV) pulses obtained from high harmonic generation (HHG) allow for studies of dynamics in molecular cations. Typical experiments using HHG have excellent time-resolution and can access processes such as charge migration, evolution of vibrational wavepackets, and fast decays through conical intersections. However, in experiments using the full bandwidth of HHG sources, signals from different states are mixed, which makes interpretation often difficult. Here, we employ a time delay compensating XUV monochromator which defines the photon energy and allows to study state-by-state dynamics and also to distinguish processes in cations from those in highly excited neutrals, because the former are present with all harmonics of sufficient energy and the latter are resonant and thus only present for a selected harmonic. In the present contribution we investigate cationic states of the CH3I molecule upon excitation with harmonic 7 (10.9 eV) which produces the CH3I+ cation in its ground state, harmonic 9 (14.0 eV) which additionally populates the first excited state and with harmonic 11 (17.2 eV) which populates higher states. The higher electronic states are purely dissociative.