Fuchs, Klaus b. December 29, 1911; Russelsheim, Hesse d. January 28, 1988; Berlin (East)
German nuclear physicist who participated in the British and American projects to produce an atomic bomb and who spied for the Soviet Union.
Klaus Fuchs came from a Protestant and Social Democratic—oriented family.
His father was the well-known theologian Emil Fuchs. In 1928, Fuchs finished school and began to study physics and mathematics at the University of Kiel. In 1930, he became a member of the Social Democratic Party (SPD) and in 1932 of the Communist Party (CP). After the Reichstag fire in late February 1933, he actively participated in the resistance against the Nazi dictatorship before he left Germany in the summer for Paris. By fall, he had emigrated to England, where he con-tinued his education at the University of Bristol. There he worked with Nevill Mott, the cofounder of modern solid-state physics and later Nobel Prize winner. In 1936, Fuchs defended his doctoral dissertation on the electron theory of metals. Following his supervisor’s recommendation, Fuchs went to the University of Edinburgh to work with Max Born, also a German emigre. In 1939, Fuchs defended his second doctoral dissertation in mathematics. After the outbreak of World War II, he was interned as an enemy alien in Canada. It was in the internment camp that he came again into contact with the CP—a connection he would not give up again.
Thanks to the support of influential colleagues, Fuchs was released from the internment camp early. He became an assistant to Rudolf Peierls at the University of Birmingham. There, Fuchs was introduced to modern nuclear physics. Peierls’s research was the center of the British project to produce an atomic bomb (“Tube Alloy”). After Fuchs went through several background checks and had become a British citizen, he was invited to participate in this project in 1941. Two years later he was sent to the United States, where he worked first in New York and later in Los Alamos for the Manhattan Project.
He was a member of the theoretical group headed by Hans Bethe. Fuchs made essential contributions to the development of the atomic bomb and was given a general overview of the entire project. Furthermore, he participated in the first discussions about a superbomb (the hydrogen bomb). Together with John von Neumann, he invented an important principle for its detonating device. In the summer of 1945, Fuchs witnessed the first successful test of an atomic bomb as well as the dropping of the atomic bomb over Hiroshima and Nagasaki. In the fall of 1945, Fuchs left Los Alamos and returned to England, where he took over the theory department in the newly established nuclear research center Harwell. There, his work focused on the development of mathematical methods for nuclear research.Before he went to the United States in 1941, Fuchs had sought contact with the Soviet secret service. He was convinced that the Soviet Union needed his support in its struggle against Nazi Germany since the Western Allies seemed temporarily unwilling to back the Soviets. Fuchs offered to disclose information about the construction of an atomic bomb acquired during his involvement in the Manhattan Project. It is still not clear how important his knowledge was for the Russian project and how much of his knowledge he transmitted to the Russian side. Nevertheless, the knowledge from the British and American projects helped the Soviet Union to acquire atomic weapons more quickly. In December 1949, the British secret service realized that Fuchs was a spy, and he was sentenced to fourteen years in prison. A year later, he lost his British citizenship. Once released from prison in June 1959, Fuchs left England for the German Democratic Republic (GDR).
In East Germany, Fuchs was warmly welcomed and was able to continue his career as a physicist. He was appointed deputy director of the GDR’s nuclear research center in Rossendorf, near Dresden and in 1972 became a member of the Academy of Science.
In 1967, he became a member of the Central Committee of the Socialist Unity Party (SED)—an honor bestowed on only a very small number of scientists. During his years in East Germany,Fuchs’s research focused on nuclear physics. He was one of the most vocal proponents of the fast-breeder reactor technology, which in the end could not be realized because of economic shortages and political pressure from Moscow.
Dieter Hoffmann
See also Braun, Wernher von; Stalin Note
References and Further Reading
Goodman, Michael S. “The Grandfather of the Hydrogen Bomb? Anglo-American Intelligence and Klaus Fuchs.” Historical Studies in the Physical and Biological Sciences 34, no. 1 (2003): 1—22.
Moss, Norman. Klaus Fuchs: The Man Who Stole the Atom Bomb. London: St. Martin’s Press, 1987.
Tschikow, Wladimir, and Gary Kern. Perseus: Spionage in Los Alamos. Berlin: Verlag Volk und Welt, 1996.
Williams, Robert Chadwell. Klaus Fuchs, Atom Spy. Cambridge: Harvard University Press, 1987.