After 35 years at Argonne National Laboratory and countless contributions to the Photon Sciences (PSC) directorate, the Advanced Photon Source (APS) and the X-ray light source scientific community, Dennis M. Mills, deputy associate laboratory director (DALD) for science and deputy director of the APS, will retire Nov. 6, 2023. 

During his tenure, Denny played an integral role in planning, successfully building – and now upgrading – the APS as a scientific user facility. He also was a founder of the National School on Neutron and X-ray Scattering (NX School), whose purpose is to educate graduate students in the use of major neutron and X-ray facilities. For nearly a decade, Denny also was the main editor of the Journal of Synchrotron Radiation.

Prior to joining the APS, Denny began his career working as a staff scientist at the Cornell High Energy Synchrotron Source (CHESS) after receiving his Ph.D. from Cornell University. In 1987, he was awarded a Guggenheim Fellowship to continue this work and held a visiting scientist post at Argonne and at the Synchrotron Radiation Source at Daresbury Laboratory, Daresbury, U.K. The following year, he joined the staff of the APS as the group leader for X-ray optics and beamlines. With his scientific expertise in the development of synchrotron X-ray optics and related techniques, Denny was responsible for the build-out of beamlines at the APS and the development of X-ray monochromators, phase plates, and timing techniques. He served as a group leader for 11 years before becoming a division director and eventually the DALD for science, a position that he has held since 2002.

Denny’s many accolades include the Advanced Photon Source Arthur H. Compton Award, the University of Chicago Pinnacle of Education Award, and fellow of the American Physical Society.

“Denny has been an integral part of the success of the APS,” said Laurent Chapon, associate laboratory director for Photon Sciences and director of the APS. “His dedication to the facility, its employees, collaborative access team members and users has been unparalleled. His scientific expertise and institutional knowledge of the APS will be greatly missed, but I wish him the very best in this next chapter.”

A search to find Denny’s successor is underway