Grant: Canada Research Chairs

The study of clusters, i. e. molecular and atomic aggregates, promises to unravel how bulk properties evolve from the microscopic scale. Spectroscopic tools will be used to measure spectra of helium atoms and hydrogen molecules containing clusters to detect indicators of superfluid behaviour. Helium nanodroplets are larger aggregates that contain thousands of helium atoms. Their superfluid nature and low temperature (0.38 K) make them an ideal spectroscopic matrix. These helium droplets will be used to study chemical reactions at low temperatures; the results will shed light on fundamental issues in reaction dynamics, for example the importance of tunnelling through reaction barriers, and will enhance our understanding of chemistry in the interstellar medium. A third aspect of the research program is the design of laser based trace gas sensors, which have applications in atmospheric chemistry, medical diagnostics, and industrial monitoring. For example, a number of molecular species present in exhaled breath can be used as markers for certain pathological conditions.