Arthur N. Jaffey was an associate chemist at the University of Chicago's Metallurgical Laboratory ("Met Lab") during the Manhattan Project.
In Recollections and Reminiscences at the 25th Anniversary of The First Weighing of Plutonium, Jaffey recalled spending his first month "learning how to shift plutonium ions from the lower to the upper state, and trying to get rid of some of the fission products by precipitating them with lanthanum ions plus hydrofluoric acid (Jaffey, p. 20)
After his training exercises, Jaffey joined the group tasked with large-scale extraction of plutonium from uranium. They received their shipment of uranium nitrate hexahydrate from the University of California, Berkeley, where the uranium had been bombarded cyclotron. According to Jaffey, the first challenge was to concentrate the plutonium from the uranium. Other problems included handling the water phase after an extraction with ether and evaporating the water at the right time (Jaffey, p. 20-25).
Jaffey was instrumental in developing the process for separating uranium, plutonium, and fission products by bromination and distillation. He and Gleen T. Seaborg were later awarded the patent (US 2965704 A) for the process on January 8, 1947.
According to the Journal of Glenn T. Seaborg, Jaffey also worked in the Instruments and Physical Measurements group led by Albert Ghiorso. In this group, he helped develop alpha particle measuring instruments and counters. He became an assistant group leader under Ghiorso in November 1944.
Jaffey briefly served as the Acting Group Leader of Group 2, Control Analysis during July 1945. He was replaced by Kohman. By August 1945, he was working as a research associate in the Heavy Isotopes groups lead by Seaborg.
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