Research Fellow in Experimental AMO Physics and Physical Chemistry Full-time

Research Fellow In Experimental Amo Physics And Physical Chemistry

The research activity that this position is connected to, within the Atomic, Molecular, Optical and Positron Physics (AMOPP) group of UCL's Physics and Astronomy Department, is related to experimental studies of cold and ultracold gas-phase ion-molecule reactive collisions within supersonic beams – a leading activity of its kind, both in the UK and worldwide.

Gas-phase ion-molecule reactions are fascinating because they can take place even in the limit of absolute zero temperature. They govern the chemistry of the interstellar medium but also present an ideal platform to exert quantum control in laboratory studies. The aim of this project is to study at low collision energies the reactions between the He+ ion and two polar molecules, in supersonic beams produced in a high-vacuum apparatus.

Ion-molecule reaction rate coefficients are strongly dependent on the molecular rotational quantum state at low collision energies. The project will comprise two phases. Phase one will involve designing and implementing an electric-field guide for focusing molecules in selected (not-reactive) rotational states to the reaction observation region, to enable the demonstration of reactivity suppression. In phase two, microwave radiation will be used to transfer the molecules from non-reactive to reactive states in order to probe the rotational-state-dependence of the reaction rate coefficients and effectively demonstrate a reactivity switch.

The successful candidate will also support ongoing research activities in the recently established research group of Dr Valentina Zhelyazkova, supported by the Royal Society University Research Fellowship scheme, and focused on developing an experimental program for studies of a range of ion-molecule reactions in supersonic beams on various energy scales (from the ultracold regime, where quantum effects dominate the reactivity to the higher energies relevant for the astrochemistry of the interstellar medium), advancing the Rydberg atom–ion substitution approach and breaking new ground in ion-molecule reaction studies at low energies.

This position is funded for 2yrs in the first instance.