This thesis presents a joint experimental and theoretical study of the state-to-state resolved rotationally inelastic scattering of NO(X) with atoms and homonuclear diatoms. Emphasis is placed on measuring the correlations between the vectors which describe the system: k and k' the initial and final relative velocities, respectively, r the initial NO bond axis orientation, and j' the final rotational angular momentum of NO. Experimentally, the initial f Δ-doublet state of NO(X) is selected using a Hexapole state selector, and the scattered NO detected using (1+1') REMPI. In the first part of this thesis the k-k' correlation in the scattering of NO(X) with O2(X) is presented. A modified onion peeling algorithm is used to extracted the (partially) pair correlated angular distributions from the experimental ion images, as well as the relative populations of O<sub>2</sub> rotational states populated during scattering. Strong similarities are observed between the scattering of NO with Ar and O<sub>2</sub>. The second part of this thesis focuses on steric effects (the r - k - k' correlation); the initial orientation of the NO bond axis is controlled using a static electric field, such that the collision partner approaches either the 'ends' or the 'sides' of the NO molecule. A new quantum mechanical theory is presented to describe the scattering of a symmetric top molecule in the presence of an arbitrarily directed electric field. The scattering of NO(X) with Ar at a collision energy of E<sub>coll</sub> = 651cm<sup>-1</sup> is presented for 'end-on' and 'side-on' scattering on the spin-orbit changing and conserving manifolds, respectively. In both cases good agreement with full quantum mechanical calculations is observed. Scattering resulting in only weak deflection is shown to be very sensitive to the orientation of the NO bond axis prior to collision, and is maximised for collisions at the 'side' of the molecule. The integral steric asymmetry for scattering of NO with N<sub>2</sub>(X) and O<sub>2</sub>(X) is also presented, and information about the potential energy surfaces for such interactions inferred.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:757862 |
| Date | January 2018 |
| Creators | Walpole, Victoria |
| Contributors | Brouard, Mark |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:5352bebb-4210-4e64-89bf-b8bf44caca92 |
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