Kurt Diebner - German Nuclear Program

German Nuclear Program

On 22 April 1939, after hearing a paper by Wilhelm Hanle on the use of uranium fission in a Uranmaschine (uranium machine, i.e., nuclear reactor), Georg Joos, along with Hanle, notified Wilhelm Dames, at the Reichserziehungsministerium (REM, Reich Ministry of Education), of potential military applications of nuclear energy. Just seven days later, a group, organized by Dames, met at the REM to discuss the potential of a sustained nuclear chain reaction. The group included the physicists Walther Bothe, Robert Döpel, Hans Geiger, Wolfgang Gentner, Wilhelm Hanle, Gerhard Hoffmann, and Joos. After this, informal work began at the Georg-August University of Göttingen, and the group of physicists was known informally as the first Uranverein (Uranium Club) and formally as Arbeitsgemeinschaft für Kernphysik. The second Uranverein began after the Heereswaffenamt (HWA, Army Ordnance Office) squeezed out the Reichsforschungsrat (RFR, Reich Research Council) of the REM and started the formal German nuclear energy project. The second Uranverein had its first meeting on 16 September 1939, which was organized by Kurt Diebner; formally, Diebner was director of the Kernforschungsrat (Nuclear Research Council), under General Carl Heinrich Becker of the HWA. It was then that Kaiser-Wilhelm Institut für Physik (KWIP, after World War II reorganized and renamed the Max Planck Institute for Physics), in Berlin-Dahlem, was placed under HWA authority, with Diebner as the administrative director, and the military control of the nuclear research commenced. Some of the research was carried out at the Versuchsstelle (testing station) of the HWA in Gottow; Diebner, was director of this facility as well as the experimental station of the RFR in Stadtilm. When it was apparent that the nuclear energy project would not make a decisive contribution to ending the war effort in the near term, control of the KWIP was returned to the its umbrella organization, the Kaiser-Wilhelm Gesellschaft (KWG, after World War II renamed the Max-Planck Gesellschaft) in January 1942 and control of the project was relinquished to the RFR that year. However, the HWA did maintain its testing station in Gottow and continue research there under Diebner’s direction until the end of the war. During Diebner’s directorship at the KWIP, considerable personal animosity had developed between Diebner and Werner Heisenberg and his scientific circle, which included Carl Friedrich von Weizsäcker and Karl Wirtz; when Diebner left the KWIP, Heisenberg became the acting director.

It was at the Gottow facility that nuclear fission experiments designated G-I and G-III were conducted. The G-1 experiment had lattices of 6,800 uranium oxide cubes (about 25 tons) in the nuclear moderator paraffin. The work verified Karl Heinz Höcker’s calculations that cubes were better than rods, and rods were better than plates. The G-III experiment was a small-scale design, but it generated an exceptionally high rate of neutron production. The G-III model was superior to nuclear fission chain reaction experiments that had been conducted at the KWIP in Berlin-Dahem, the University of Heidelberg, or the University of Leipzig. Work was also done to explore the initiation of a nuclear reaction through the detonation of explosives.

In the latter part of World War II, in addition to his other responsibilities, Diebner was a Reich Planning Officer.