Mason Marshall is a postdoctoral researcher in the Ion Storage Group. His work focuses on precision measurement for tests of fundamental physics. Currently, he is working to develop a next-generation optical atomic clock using jointly trapped magnesium and aluminum ions, with the goal of improving clock stability while maintaining the aluminum clock's unparalleled accuracy. A more stable aluminum clock could be used as a reference or probe for spectroscopic tests of physics beyond the standard model, as well as advancing time metrology. Previously, he studied dark matter detection using solid-state quantum sensors in diamond as a postdoctoral fellow at the Harvard-Smithsonian Center for Astrophysics. He received his Ph.D. in physics from Harvard in 2019 for work on the precision comparison of the proton and antiproton magnetic moments.