Operation Epsilon

Frome June to December 1945, ten leading German scientists, variously connected with Atomic Energy research, were detained, incommunicado, at Farm Hall, Godmanchester, near Cambridge, England. The scientists detained were Erich Bagge, Kurt Diebner, Walther Gerlach, Otto Hahn, Paul Harteck, Werner Heisenberg, Horst Korsching, Max von Laue, Carl Friedrich von Weizsacker and Karl Wirtz. Their conversations were secretly recorded by British Intelligence.

Background
Throughout the work on the Manhattan Project directed by Major General Leslie R Groves, those engaged saw themselves as in a race with the Germans who had a head-start since nuclear fission had been discovered by Hahn in Germany at the end of 1938.

The ALSOS mission, under the scientific leadership of Samuel A Goudsmit, was charged with following closely behind the Western Allied invading forces in 1944 to locate and seize personnel, documents and material concerned with the German Atomic Bomb programme. Though the evidence collected by November 1944 was enough to convince Goudsmit that there was no German Atom Bomb in the making, there continued to be many, particularly in America, who would not believe it.

So the mission continued with much the same target, at least for Intelligence purposes. These ten individuals were selected by Goudsmit. Among those picked up, mostly at Hechingen, by an Anglo-American raiding party, which had made its way through a gap in the crumbling German front, under the leadership of Colonel Boris T Pash, the principal military officer of ALSOS. Hechingen is on the Eastern edge of the Black Forest. It was there that the greater part of the Kaiser Wilhelm Institut fur Physik, in particular with its uncompleted nuclear reactor pile, had been relocated after being bombed out from Berlin.

It was R V Jones who pointed out that Farm Hall in England, which belonged to the British Secret Service, would be a suitable place to house them. He also suggested that microphones should be installed there before they arrived. This had become standard practice with senior prisoners-of-war. Experience had shown that their private conversations could be more revealing than interrogation.