"Electron Impact Ionization Experiments at The University of Manchester", department colloquium, March 23, 2012, 12 noon

Kate Nixon, University of Manchester

Electron collisions resulting in ionization are important in a wide number of areas.  These include: the development of lasers, the chemistry of the Earth's upper atmosphere and the treatment of cancers with radiotherapies.  The research at University of Manchester has three themes all aimed to further understand these important collisions.

The first theme uses atomic targets. High quality data for electron scattering from atomic targets can be compared to predictions from sophisticated quantum mechanical models.  The level of agreement between the experimental and theoretical data shows if the physics of the collisions between electrons and atoms is being modelled accurately. New data has been measured for Ne, Ar, Kr and Xe.

The second research theme is to develop an understanding of electron-molecule collisions. Molecular targets are more complex than atomic target and provide challenges for both experimentalists and theorists. A systematic study of atomic and molecular targets with the same number of electrons has been undertaken using neon, CH4, NH3 and H2O.  Comparison of the results for all of these targets highlight which features of the data are due to the electronic structure or the molecular nature of the target.

One of the major challenges for theorists in modelling electron collisions with molecules is how to account for the random orientation of the molecules within typical experiments. The third theme at the University of Manchester is to align the targets before the electron collision. A new experiment is being developed to measured data from aligned H2.