Studies of Photoinduced Molecular Dynamics Using a Fast Imaging Sensor

The work presented in this thesis involves a number of sophisticated experiments highlighting novel applications of the Pixel Imaging Mass Spectrometry (PImMS) camera in the field of photoinduced molecular dynamics. This approach represents the union of a new enabling technology (a multiple memory register, CMOS-based pixel detector) with several modern chemical physics approaches and represents a significant leap forward in capabilities. Applications demonstrated include three-dimensional imaging of photofragment Newton spheres, simultaneous electron-ion detection using a single sensor, and ion-ion velocity correlation measurements that open the door to novel covariance imaging experiments. When combined with Coulomb explosion imaging, such an approach is demonstrated to allow the measurement of molecular structure and motion on a femtosecond timescale. This is illustrated through the controlled photoexcitation of torsional motion in biphenyl molecules and the subsequent real-time measurement of the torsional angle.

Auteur
Craig holds a first-class master's degree in chemistry and a doctorate in physical chemistry, both from the University of Oxford. Craig's research interests centre around the application of fast imaging sensors to the study of gas phase photochemical dynamics, in particular those processes involving photoinduced Coulomb explosion of polyatomic molecules.

Contenu
Introduction and Motivation.- Experimental Techniques and Methods of Data Analysis.- Three-Dimensional Velocity-Map Imaging.- Pulsed-Field Electron-Ion Imaging.- Principles of Coulomb Explosion Imaging.- Investigations of Coulomb Explosion Dynamics.- Time-resolved Studies of Induced Torsional Motion.