Thomas is director of the Neutron Data Analysis and Visualization Division in the Neutron Sciences Directorate where he leads researchers in advancing neutron data collection, data analysis, and the integration of computer modeling at multiple steps in data collection and analysis workflow. He has more than 20 years of experience developing and leading neutron research. At ORNL, he served as Diffraction Group Leader over several diffractometers at the Spallation Neutron Source and High Flux Isotope Reactor. At the Lujan Neutron Scattering Center at Los Alamos National Laboratory, he oversaw the upgrade of the center's Neutron Powder Diffractometer in 2002, which has since facilitated more than 130 peer-reviewed papers. Himself an author on more than 160 peer-reviewed papers, he has served on advisory panels or committees for the Neutron Scattering Society of American, the European Spallation Source, and the American Crystallographic Association.