Community deaths Obituaries of residents from the District, Maryland and Northern Virginia. Thomas McIlrath,
physicist Dr. Thomas McIlrath, 82, a retired physicist who did early research in the use of lasers to explore the structure of atoms and ions while teaching at the University of Maryland’s Institute for Physical Science and Technology, died Dec. 20 at a hospital in Washington. The cause was end-stage Parkinson’s disease, said his daughter Christine Lehnigk. Dr. McIlrath’s scientific discovery of resonant laser ionization led to new insights into the energy levels in ions and had applications in energy research. He taught at the University of Maryland for 22 years until 1995 and served as associate dean for research and graduate studies. He was treasurer and chief financial officer of the American Physical Society for 10 years until 2006, a fellow of the Optical Society, and a former guest researcher and collaborator at the National Institute of Standar