Opaline Calhoun was a laboratory technician at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project. She began working under research assistant Phillip Fineman in the Chemistry Divisions’ Section C-1 on September 24, 1945. Within the Section C-1, Calhoun worked in the Control Analysis and Heavy Isotopes Groups from 1945 to 1946.
For more information about Opaline Calhoun and women of the Manhattan Project, see the following reference: