born Dec. 29, 1911, Rüsselsheim, Ger.
died Jan. 28, 1988, E.Ger.
German physicist and spy.
He joined the German Communist Party in 1930 but fled Germany after the Nazi takeover in 1933. He settled in Britain, earned a doctorate at the University of Edinburgh, and became a British citizen in 1942. He worked on the atomic bomb in Britain and the U.S. In 1943 he began passing scientific secrets to the Soviet Union, which accelerated Soviet development of the atomic bomb by at least a year. His activities were detected in 1950, and he was imprisoned until 1959. After his release, he moved to East Germany, where he was appointed deputy director of the Central Institute for Nuclear Research.