National Museum of Nuclear Science & History
Harold Evans was an American chemist. Evans was born in 1907 in Brazil, Indiana. He received a B.S. and an M.
Herbert M. Parker (1910-1984) was a British-American medical physicist. He worked at Chicago, Oak Ridge, and Hanford during the Manhattan Project, and is perhaps best known for inventing the rep (a precursor of the rad) and helping develop the rem to measure radiation dosage.
Mary Lou Curtis joined the Manhattan Project in Dayton, Ohio in 1943. Mrs. Curtis worked in the Counting Room at Monsanto’s Unit III facility, where she developed new methods to measure and analyze radioactive materials, such as polonium, which was used as the trigger for the atomic bombs.