April 22, 1944 – October 30, 2023

Paul Michael DeLuca Jr. died on October 30, 2023. He was born in 1944 and grew up in Troy NY, the son of Dr. Paul and Dorothy DeLuca. He received his BS in Physics from New York’s Le Moyne College and a Ph.D. in nuclear physics from the University of Notre Dame in 1971. He came to the University of Wisconsin (UW) as a physics postdoctoral fellow immediately after getting his Ph.D. He was soon recruited by Professor John Cameron to join the UW Department of Radiology and began teaching radiation health physics. He researched the radiation biology of neutrons using low-energy deuterium ions interacting in a tritium gas target – the same kind of reaction required for a fusion power reactor – and compared it to Co-60 radiation. His system design was not trivial as it required the accelerator to be in a hard vacuum and the tritium at a reasonable pressure to get sufficient nuclear reactions. He solved this with a series of differential vacuum pumps to create a pressure gradient of six orders of magnitude between the tritium in the reaction vessel and deuteron accelerator. Zooming ahead 40 years, he was advising Wisconsin companies Phoenix Nuclear and Shine Medical Technologies to use the same technology to produce neutrons for imaging, radiation effects testing and production of medical isotopes. His great loves were his wife Florence, and his children Paul M. DeLuca III and Kelly. He greatly enjoyed Italian food, fine red wines, and interesting conversation with friends. But he spent much of his life in complex and difficult leadership to the UW and the ICRU.

Paul joined the inaugural UW Department of Medical Physics when it was formed from groups in Physics and Radiology in 1981 and in 1987 became the Chair of the department which was anchored by an NIH Training grant. He was early to realize the importance of industry collaboration of applied science and was instrumental in enabling landing a General Electric (GE) Medical Master Research agreement that has continued for three decades whereby GE and UW scientists and UW clinicians evaluate their new technology before launching them into general clinical use. He served as department Chair until he was promoted to the Associate Dean for Research and later to the Vice-Dean in the UW School of Medicine and Public Health. In that decade-long capacity, he served several deans and became the steady hand through an extremely rapid growth phase that developed the large modern Wisconsin Institute for Medical Research. As a capstone achievement of his UW career, he became the Provost of the UW for another decade, effectively the Chief Operating Officer of the University. His tenure as Provost led to a nearly complete turnover of the biotechnology research infrastructure on campus as well as the new Wisconsin Institutes for Discovery, a private-public partnership in remarkable research and collaboration space.

Paul DeLuca was a teacher and mentor for many future scientists. He directed, or trained, almost 50 graduate students and postdocs, mostly in Medical Physics and also in Physics and Nuclear Engineering. He was a firm believer in the value of basic science as the foundation of medical physics.

Paul served as a major contributor to the International Commission of Radiation Units and Measurement (ICRU) for nearly 30 years. He began as a Commissioner of the ICRU in 1994. From 1997-2018 was the Vice-Chair of the ICRU except for the period from 2006-2009 when he served as Chair. He continued to serve the ICRU as an Honorary Chair until his death. Professor DeLuca served during an exceptional time for the ICRU as it increased its commitment to the science of radiation medicine while maintaining its role as “guardian” of the metrology of ionizing radiation for radiation protection. Highlights of his tenure include systematic recommendations for radiation sciences that worldwide impact tens of millions of people annually including radiation oncology prescribing, recording, and reporting as well as dosimetry and quality evaluation of medical imaging scanning. His passing truly signals the passing of the era of rapid advances in the radiation sciences. His former students, colleagues and ICRU Commissioners will miss his leadership, wisdom, energy, and wry good humor.

Rock Mackie
María Ester Brandan
Hans Menzel