Jonathan Dean is a postdoctoral research fellow in the Quantum Sensors Division of the Physical Measurement Laboratory at NIST in Boulder, CO. He joined NIST in September 2024 after completing his PhD in theoretical atomic physics in Melbourne, Australia. Transitioning from theory to experiment, Jonathan’s postdoctoral work focuses on a novel method for high-precision, SI-traceable X-ray energy measurements. Using a steerable pulsed laser and superconducting cryogenic microcalorimeters, this technique enables parts-per-million level precision measurement of X-ray spectra in semiconductor materials to support the CHIPS Act. Jonathan also collaborates on projects with CERN, NASA, and the Berlin Synchrotron (BESSY II) to install and operate transition-edge sensor (TES) microcalorimeter arrays. Additionally, he supports in-house highly charged ion research within the Quantum Sensors Division.