Klaus Fuchs, a refugee German physicist, and Communist Party member, was employed by the United Kingdom atomic energy program during World War II, and was sent to work on the Manhattan Project at Los Alamos. Fuchs was a gifted physicist who made major contributions to the Manhattan Project in the theory of gaseous diffusion cascades, and in implosion theory.
He is also the famous "Atom Spy" who transferred to the Soviet Union, via Harry Gold and the Rosenbergs, virtually everything he knew about atomic weapons.
After the war Fuchs was employed in a prominent position by the UK Atomic Energy Authority in weapons development until his discovery and arrest. Evidence of Fuchs spying surfaced from U.S. intelligence intercepts known as Venona, in particular a Soviet consulate massage transmitted in 1944, but not deciphered until 1949. The FBI began a full-scale investigation in September 1949, and on 27 January 1950 he confessed to MI5. This discovery probably accelerated the U.S. hydrogen bomb effort, which had been announced by President Truman only four days after Fuchs' arrest.
After serving 9 years in prison, he was released to East Germany where he became a lecturer in physics.
Above is a picture of Klaus Fuchs in East Germany in 1960.
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