Seminar: New methods of studying ions and radicals at low temperatures

Join speaker Brianna Heazlewood, of the University of Liverpool, as she discusses new techniques for studying ions and radicals at low temperatures.

Brianna joined Liverpool in 2021 as an EPSRC Early Career Fellow, moving from the Department of Chemistry at the University of Oxford. She obtained her undergraduate and PhD degrees from the University of Sydney, Australia.

Her research uses low temperatures to explore how reactive collisions occur. Cold environments allow her team to control the properties of reactants, providing information about the reaction processes and the underlying potential surfaces. Much of this detail is lost at higher temperatures, where thermal averaging complicates our interpretation of the dynamics at play. In the past few decades, extraordinary progress has been made in the development of techniques that allow us to manipulate cold species. Her team employs a number of these techniques, including laser cooling and the application of external electric and magnetic fields, to investigate reactive collisions between ions and neutral species.

New methods for studying ions and radicals at low temperatures 

J. A. Diprose, R. Pandey, P. Regan, V. Richardson, M. Roman, L. Y. Wu, and B. R. Heazlewood

In spite of their real-world importance, it is difficult to study gas-phase reactions between ions and radicals at low temperatures. Here, I will present our approach for generating beams of velocity- and state-selected radicals with tuneable properties [1-2]. We have recently combined our radical beam source with a cryogenic ion trap, for the study of ion–radical reactions under cold and controlled conditions (see fig. 1, above). Reactions will take place within Coulomb crystals, enabling us to monitor processes with exceptional sensitivity (down to the single-ion level) [3]. The advantages of studying reactions within a Coulomb crystal environment will be discussed, and a new imaging method that enables spatial and temporal detection of ions will be presented.

References

1. J. Toscano, C. J. Rennick, T. P. Softley, and B. R. Heazlewood, “A magnetic guide to purify radical beams” J. Phys. Chem., 149, 174201 (2018). 
2. C. Miossec, L. Y. Wu, P. Bertier, M. Hejduk, and B. R. Heazlewood, “A stand-alone magnetic guide for producing tuneable radical beams” J. Chem. Phys., 153, 104202 (2020). 
3. A. Tsikritea, K. Park, P. Bertier, J. Loreau, T. P. Softley, and B. R. Heazlewood, “Inverse kinetic isotope effects in the charge transfer reactions of ammonia with rare gas ions” Chem. Sci., 12, 10005 (2021).