Photodissociation as a probe of the H$_3^+$ avoided crossing seam
arXiv:1908.03162 · doi:10.1098/rsta.2018.0399
The paper studies how the avoided crossing seam influences the photodissociation of H₃⁺ ions using 3D imaging to measure product energies and branching ratios, and models the wavepacket dynamics on repulsive surfaces.
Abstract
Experiments are conducted to investigate the role of the avoided crossing seam in the photodissociation of H$_3^+$. Three-dimensional imaging of dissociation products is used to determine the kinetic energy release and branching ratio among the fragmentation channels. Vibrational distributions are measured by dissociative charge transfer of H$_2^+$ products. It is found that the photodissociation of hot H$_3^+$ in the near ultraviolet produces cold H$_2^+$, but hot H$_2$. Modelling the wavepacket dynamics along the repulsive potential energy surface accounts for the repopulation of the ground potential energy surface. The role of the avoided crossing seam is emphasized and its importance for the astrophysically relevant charge transfer reactions is underlined.
Contribution to the meeting "Advances in hydrogen molecular ions: H3+ , H5+ and beyond"