Klaus Fuchs

Today is the birthday of Klaus Fuchs, a nuclear physicist who was convicted of sharing US and British atomic secrets with the Soviet Union. He was born in Rüsselsheim, Germany in 1911. Fuchs fled Germany and the Nazis in 1933 because he was a member of the German Communist Party. He moved to Great Britain, where he earned his PhD and worked under Max Born at the University of Edinburgh. With Born’s support, Fuchs joined the British effort to build an atomic bomb. In 1943 he was part of a group of British scientists sent to New York to study uranium enrichment with the Manhattan Project. The following year he was transferred to Los Alamos, where he witnessed the Trinity nuclear test. After the war Fuchs returned to Britain and led the physics department at the Harwell Atomic Energy Research Establishment. In 1949 the US decrypted communications revealing that Fuchs was a Soviet spy. He was arrested, charged with violating Britain’s Official Secrets Act, and sentenced to 14 years in prison (he ended up serving nine). Fuchs’s espionage is thought to have accelerated the USSR’s atomic bomb program by a year or two, and he also passed on details about the hydrogen bomb. After his release from prison, Fuchs became deputy director of the Central Institute for Nuclear Research in Rossendorf, East Germany. (Photo credit: DEFA-Photo, German Democratic Republic, courtesy AIP Emilio Segrè Visual Archives, Physics Today Collection)

Date in History: 29 December 1911