Abstract
Bound and free quantum resonances of molecular hydrogen exhibiting wave-function density at large internuclear separation, (Formula presented.) 4–5 a.u., are excited via multi-step laser spectroscopy. Highly excited vibrational levels of H (Formula presented.) are prepared via two-photon UV-photolysis of H (Formula presented.) S. Subsequent two-photon Doppler-free precision measurements are performed connecting (Formula presented.) levels with (Formula presented.) outer-well levels. Detection and spectroscopic labelling of the quantum states is assisted by further laser excitation into the auto-ionisation continuum employing a third UV-laser. Level energies of high rotational states ((Formula presented.)) in the outer-well state (Formula presented.) are accurately determined. The three-laser study demonstrates a method for probing resonances in the H (Formula presented.) ionisation continuum with wave-function density at large internuclear separation (Formula presented.) 4–5 a.u., large angular momenta J, and energy range 131,100–133,000 cm −1, a hitherto unexplored territory.
Original language | English |
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Pages (from-to) | 2961-2971 |
Number of pages | 11 |
Journal | Molecular Physics |
Volume | 117 |
Issue number | 21 |
Early online date | 29 Mar 2019 |
DOIs | |
Publication status | Published - 2 Nov 2019 |
Keywords
- Molecular hydrogen
- autoionisation
- complex resonance
- laser spectroscopy
- outer-well states