Rayment, Matthew Henry;
(2023)
Experiments with electrostatically trapped NO and N2 molecules in high Rydberg states.
Doctoral thesis (Ph.D), UCL (University College London).
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Abstract
In this thesis, nitric oxide (NO) and nitrogen (N₂) molecules, initially travelling in pulsed supersonic beams, have been laser photoexcited into long-lived Rydberg states in series that converge to selected rotational and vibrational states of the molecular cations. Molecules prepared in these excited states were subsequently guided, decelerated, and trapped, from an initial speed of 800 m s¯¹ in the laboratory-fixed frame of reference, using the travelling electric fields of a cryogenically-cooled chip-based Rydberg-Stark decelerator. Electrostatic trapping was achieved for up to 10 ms, and enabled the study of slow-decay processes of the long-lived Rydberg states these molecules over these previously inaccessible timescales. Measurements of the trap decay time constants, of the total population of trapped molecules, were made after excitation into Rydberg states with principal quantum numbers, n, between 32 and 50. For the experiments with NO, molecules were excited into Rydberg states converging to the N⁺ = 0 to 6 rotational, and v⁺ = 0 and 1 vibrational states of the X⁺ ¹Σ⁺ ground electronic state of the NO⁺ cation. This allowed investigation of the effects of rotational and vibrational excitation on the decay dynamics of the long-lived Rydberg states. Although such rotational state selectivity was not possible in the excitation of the N₂ molecules to Rydberg states, long-lived Rydberg states converging toward the v⁺ = 0 series limit were prepared and trapped in experiments, permitting comparison of the decay dynamics of long-lived Rydberg states of different species.
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Experiments with electrostatically trapped NO and N2 molecules in high Rydberg states |
| Open access status: | An open access version is available from UCL Discovery |
| Language: | English |
| Additional information: | Copyright © The Author 2022. Original content in this thesis is licensed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) Licence (https://creativecommons.org/licenses/by-nc/4.0/). Any third-party copyright material present remains the property of its respective owner(s) and is licensed under its existing terms. Access may initially be restricted at the author’s request. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10181033 |
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