"Strong-field phenomena involving lasers, ions, atoms, and molecules"

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1) Some of the most advanced experiments on molecule-laser interactions were carried out in NRC laboratories in Ottawa in the past few years. They aim to explain the process where radiation from a laser is absorbed by a simple molecule, such as nitrogen or carbon dioxide. Electrons temporarily ionized by the laser pulse and accelerated to high velocities are driven back onto the ionic molecule. In the recombination process, where the freed electron is captured back, photons of very high energy are emitted. These photons can form a very-short wavelength coherent pulse themselves. Work is proposed to model the role of different electrons responsible for the binding of the molecule in this ionization-recombination process. A better understanding of the mechanisms involved may serve as a guide to create short-pulse lasers that operate in the X-ray regime. 2) Intermediate-energy collisions of ions with water molecules will be modelled. Ion radiation therapy has become an alternative to conventional radiation methods for cancer therapy. Our calculations of fragmentation of water molecules by these ions will provide a better understanding of the fundamental processes. It will eventually lead to improvements in the application of energy deposition by ion beams for radiation therapy. 3) Modelling will be carried out to understand ultra-high precision measurements of simple atoms, such as helium and alkali atoms. This modelling incorporates more physics than is usually done in spectroscopy analysis, particularly the interference of spontaneously emitted radiation. The aim is to support experiments which aim at the determination of fundamental constants with improved accuracy, such that the very foundations of our understanding of electron-photon can be tested more deeply.