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Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Above threshold dissociation of vibrationally cold HD+ molecules
P A Orr1, I D Williams, J B Greenwood
1School of Maths and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom.
Researchers studied molecular dissociation of hydrogen ions (H2+) using intense laser pulses. They observed above threshold dissociation from the ground vibrational state in cooled HD+ ions, with four-photon absorption being dominant at high intensities.
Area of Science:
- Molecular physics
- Quantum chemistry
- Laser-matter interactions
Background:
- Molecular dissociation of ions like H2+ is complex due to varying initial vibrational states.
- Previous studies faced challenges in isolating specific vibrational states for laser interaction experiments.
Purpose of the Study:
- To investigate the molecular dissociation of HD+ ions using intense laser pulses.
- To observe and analyze above threshold dissociation from the ground vibrational state.
Main Methods:
- Utilized an electrostatic storage device for radiative cooling of HD+ ions.
- Employed 40 fs laser pulses at 800 nm to induce dissociation.
- Analyzed dissociation pathways at varying laser intensities.
Main Results:
- Successfully cooled HD+ ions to the ground vibrational state.
- Observed above threshold dissociation, indicating energy absorption beyond the minimum required.
- Identified dissociation via absorption of at least four photons as the dominant process at high laser intensities.
Conclusions:
- Radiative cooling is effective for preparing ions in specific vibrational states for laser dissociation studies.
- Above threshold dissociation in HD+ is significantly influenced by laser intensity.
- Multi-photon absorption plays a crucial role in the dissociation dynamics of molecular ions under intense laser fields.
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