Table of contents

The nonthermal effect on resonant Compton scattering of photons by the He (1s^{2 1}S) ground state is investigated in Lorentzian astrophysical plasmas using exponential correlated basis functions and with a variational technique. The nonthermal character of the Lorentzian plasma enhances the resonant Compton scattering cross sections.

Low-order (3^rd to 9^th) harmonic generation of a near-infrared driving laser (1064 nm) is reported in a laser ablation plasma of ZnS. Temporal analysis shows two distinct components with respect to the ablation event. The late temporal component exhibits high conversion efficiency for the highest harmonic orders observed. This is attributed to a dramatic modification of the plasma medium with the driving laser.

Ultrafast electron dynamics in the low-femtosecond regime was evaluated for a low band-gap polymer and its blend with fullerene by resonant Auger spectroscopy. Remarkable changes developed by tuning the photon energy along the sulfur and silicon 1s absorption edges. The effect of thermal annealing and molecular orientation on the charge transfer delocalization times were probed and correlated with solar cells performance.

The use of Multivariate Normal Distribution was used to represent the whole spectra as combination of parameters. Fragmentation and ionic dissociation of dimethyl disulfide (CH₃SSCH₃ or DMDS) at 800 eV is studied for single and multiple coincidence. The proposed methodology allows to obtain dissociation parameters when there is an overlap of the ion-ion data spectrum.

We theoretically demonstrate that harmonic emission could be achieved from Rydberg atoms without deteriorating the nanostructures.

Here we describe our use of cells with nm scale thickness ('nanocells') to investigate inter-atomic, atom- light and atom-surface interactions. Such cells allow us to access high density regimes previously unexplored in vapour cell spectroscopy, and to probe the interaction of atoms within the near field of surfaces, where atoms interact with their own virtual image. We also discuss the future fabrication of such cells in Durham.