Mary-Ellen Donnelly

Mary-Ellen is an Associate Scientist within the Strategic Support Group at the Canadian Light Source. She specializes in diffraction techniques and in situ experiments under extreme conditions, supporting researchers in advancing complex materials studies.

Mary-Ellen earned both her MSc. and PhD. in physics from the University of Edinburgh, Scotland, where her research focused on the crystal structures and high-pressure phase transitions of inclusion compounds, such as gas hydrate clathrates. Following her PhD, she held postdoctoral positions investigating the behaviour of hydrogen-rich materials and mixtures under compression using x-ray diffraction, Raman spectroscopy, and neutron scattering.

Before joining CLS in 2024, Mary-Ellen held technical roles at leading neutron user facilities. She served as a Scientific Associate for the VENUS instrument at the Spallation Neutron Source (Oak Ridge National Laboratory) and as an Instrument Operations Engineer for the Test Beamline at the European Spallation Source in Sweden. Drawing on more than a decade of combined experience as both a user and beamline scientist at neutron and x-ray facilities, she now helps new CLS researchers navigate and apply advanced synchrotron techniques to their work.

Outside of the laboratory, Mary-Ellen enjoys hiking, baking bread, and playing board and video games.