Thomas Bailey successfully defended his Ph.D. thesis on October 21, 2025 entitled “Developing reference standards for ²³⁶U Accelerator Mass Spectrometry capabilities at the University of Notre Dame” advised by Prof. Philippe Collon.

The natural abundance of ²³⁶U in nature varies over a few orders of magnitude between different mine locations and any individual location’s abundance of ²³⁶U has long been considered a unique “fingerprint”-like signature. Thomas’ thesis work to develop a series of ²³⁶U standards will for the very first time ever allow Accelerator Mass Spectrometry (AMS) measurements of this actinide over the overall full range of its natural abundances with appropriate standards. In collaboration with the IAEA these standards will be provided to other laboratories around the world. This work has been the subject of a number of publication and a final publication is being finalized. Under Thomas’ leadership, many new improvements in actinide AMS measurements were made at the NSL and his guidance and mentoring of his fellow group members has allowed them to flourish. Thomas has also participated in a number of AMS measurements at Argonne National Laboratory dedicated to National Ignition Facility (NIF) Physics.