Robert Döpel

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Georg Robert Döpel (3 December 1895 in Neustadt – 2 December 1982 in Ilmenau) was a German experimental nuclear physicist. He was a participant in a group known as the “first Uranverein,” which was spawned by a meeting conducted by the Reichserziehungsministerium, in April 1939, to discuss the potential of a sustained nuclear reaction. He worked under Werner Heisenberg at the University of Leipzig, and he conducted experiments on spherical layers of uranium oxide surrounded by heavy water. He was a contributor to the German nuclear energy project (Uranverein). In 1945, he was sent to Russia to work on the Soviet atomic bomb project. He returned to Germany in 1957, and he become professor of electrical engineering and director of the Institut für Angewandte Physik at the Hochschule für Elektrotechnik.

Contents 1 Education 2 Career 2.1 In Germany 2.2 In Russia 2.3 Back in Germany 3 Internal Reports 4 Selected Literature 5 Books 6 Bibliography 7 Notes

[edit] Education

From 1919 to 1924, Döpel attended the University of Leipzig, the Friedrich Schiller University of Jena, and the Ludwig Maximilian University of Munich (LMU). He received his doctorate, in 1924, under the Physics Nobel Lauriat Wilhelm Wien at LMU.^[1]

[edit] Career

[edit] In Germany

After receipt of his doctorate, Döpel became Robert W. Pohl’s teaching assistant at the Georg-August University of Göttingen. He also worked with the Physics Nobel Lauriat Johannes Stark on canal rays, at the private laboratory of Rudolf Freihern von Hirsch zu Planegg, just west of Munich.^[2]

In 1929, Döpel became a teaching assistant at the Julius-Maximilians-Universität Würzburg, and in 1932 he became a Privatdozent there.^[3]

In 1939, Döpel became an extraordinarius professor at the University of Leipzig, where he was a colleague of Werner Heisenberg. At some point, Döpel succeeded Fritz Kirchner as professor of radiation physics.^{[4] [5]}

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, Döpel, Hans Geiger, Wolfgang Gentner, Wilhelm Hanle, Gerhard Hoffmann, and Joos. After this, informal work began at the 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 (Army Ordnance Office) squeezed out the Reichsforschungsrat (Reich Research Council) of the Reichserziehungsministerium and started the formal German nuclear energy project. The second Uranverein had its first meeting on 16 September 1939; the meeting was organized by Kurt Diebner and held in Berlin.^{[6] [7] [8]}

In August 1940, Döpel, working in Leipzig, showed the utility of using heavy water as a moderator in a nuclear reactor. He conducted experiments with a spherical geometry (hollow spheres) of uranium surrounded by heavy water. Trial L-I was done in August 1940, and L-II was conducted six months later. Results from trial L-IV, in the summer of 1942, indicated that the spherical geometry, with five metric tons of heavy water and 10 metric tons of metallic uranium, could sustain a fission reaction. The results were set forth in an article by Döpel, Döpel’s wife Klara, and Werner Heisenberg.^[9] The article was published in the Kernphysikalische Forschungsberichte (Research Reports in Nuclear Physics), a classified internal reporting vehicle of the Uranverein. 1942 was the year in which supervision of the Uranverein was transferred from the Heereswaffenamt to the Reichsforschungsrat.^{[10] [11]}

Döpel’s wife Klara was also an experimental physicist, and she worked on the nuclear reactor experiments with him in Leipzig.^[12]

In a letter written in December 1943, Döpel recounted that air raids had destroyed 75% of Leipzig, including his institute. Air raids during that year had also burned down Döpel’s apartment building and Heisenberg’s house in Leipzig. Sixteen months later, on April 6, 1945, just 32 days before the surrender of Germany, Klara was killed in an air raid, while she was working in the physics building.^{[13] [14]}

[edit] In Russia

Near the close of World War II, the Soviet Union sent special search teams into Germany to locate and deport German nuclear scientists or any others who could be of use to the Soviet atomic bomb project. The Russian Alsos teams were headed by NKVD Colonel General A. P. Zavenyagin and staffed with numerous scientists, from their only nuclear laboratory, attired in NKVD officer’s uniforms. The main search team, headed by Colonel General Zavenyagin, arrived in Berlin on 3 May, the day after Russia announced the fall of Berlin to their military forces; it included Colonel General V. A. Makhnjov, and nuclear physicists Yulij Borisovich Khariton, Isaak Konstantinovich Kikoin, and Lev Andreevich Artsimovich. Döpel was sent to the Soviet Union to work on their atomic bomb effort. Döpel worked at the Nauchno-Issledovatel’skij Institut-9 (NII-9, Scientific Research Institute No. 9), in Moscow. There, he worked with Max Volmer on the production of heavy water.^{[15] [16] [17]}

[edit] Back in Germany

Döpel returned to Germany in 1958. He became professor of electrical engineering and director of the Institut für Angewandte Physik (Institute for Applied Physics) at the Hocschule für Elektrotechnik (today the Technische Universität Ilmenau). There, he conducted spectral analysis of the mechanism of electric discharges in gases.^{[18] [19]}

[edit] Internal Reports

The following reports were published in Kernphysikalische Forschungsberichte (Research Reports in Nuclear Physics), an internal publication of the German Uranverein. The reports were classified Top Secret, they had very limited distribution, and the authors were not allowed to keep copies. The reports were confiscated under the Allied Operation Alsos and sent to the United States Atomic Energy Commission for evaluation. In 1971, the reports were declassified and returned to Germany. The reports are available at the Karlsruhe Nuclear Research Center and the American Institute of Physics.^{[20] [21]}

• Robert Döpel, K. Döpel, and Werner Heisenberg Bestimmung der Diffusionslänge thermischer Neutronen in Präparat 38^[22] (5 December 1940). G-22.^[23]

• Robert Döpel, K. Döpel, and Werner Heisenberg Bestimmung der Diffusionslänge thermischer Neutronen in schwerem Wasser (7 August 1940). G-23.^[24]

• Robert Döpel, K. Döpel, and Werner Heisenberg Versuche mit Schichtenanordnungen von D₂O und 38 (28 October 1941). G-75.^[25]

• Robert Döpel Bericht über Unfälle beim Umgang mit Uranmetall (9 July 1942). G-135.^[26]

• Robert Döpel, K. Döpel, and Werner Heisenberg Der experimentelle Nachweis der effektiven Neutronenvermehrung in einem Kugel-Schichten-System aus D₂O und Uran-Metall (July 1942). G-136.^[27]

• Robert Döpel, K. Döpel, and Werner Heisenberg Die Neutronenvermehrung in einem D₂O-38-Metallschichtensystem (March 1942). G-373.^[28]

[edit] Selected Literature

• Robert Döpel Elektromagnetische Analyse von Kanalstrahlen, Annalen der Physik Volume 381, Number 1, 1-28 (1925)

• Robert Döpel Über den selektiven Photoeffekt am Strontium, Zeitschrift für Physik Volume 33, Number 1, 237-245 (December, 1925). The author was identified as being at the I. physikalisches Institut der Universität, Göttingen. The article was received on 3 June 1925.

• Robert Döpel Kernprozesse bei der mittleren Korpuskularenergie von Sternzentren, Naturwissenschaften Volume 24, Number 15, 237- (April, 1936)

[edit] Books

• Robert Döpel Kanalstrahlröhren als Ionenquellen (Akademie-Verlag, 1958)

• Werner Heisenberg, Robert Döpel, Wilhelm Hanle, and Käthe Mitzenheim Werner Heisenberg in Leipzig 1927-1942 (Wiley-VCH, 1993)

[edit] Bibliography

• Hentschel, Klaus (editor) and Ann M. Hentschel (editorial assistant and translator) Physics and National Socialism: An Anthology of Primary Sources (Birkhäuser, 1996) ISBN 0-8176-5312-0

• Kant, Horst Werner Heisenberg and the German Uranium Project / Otto Hahn and the Declarations of Mainau and Göttingen, Preprint 203 (Max-Planck Institut für Wissenschaftsgeschichte, 2002)

• Kruglov, Akadii The History of the Soviet Atomic Industry (Taylor and Francis, 2002)
• Maddrell, Paul Spying on Science: Western Intelligence in Divided Germany 1945–1961 (Oxford, 2006) ISBN 0-19-926750-2

• Macrakis, Kristie Surviving the Swastika: Scientific Research in Nazi Germany (Oxford, 1993)

• Oleynikov, Pavel V. German Scientists in the Soviet Atomic Project, The Nonproliferation Review Volume 7, Number 2, 1 – 30 (2000). The author has been a group leader at the Institute of Technical Physics of the Russian Federal Nuclear Center in Snezhinsk (Chelyabinsk-70).

• Riehl, Nikolaus and Frederick Seitz Stalin’s Captive: Nikolaus Riehl and the Soviet Race for the Bomb (American Chemical Society and the Chemical Heritage Foundations, 1996) ISBN 0-8412-3310-1.

• Walker, Mark German National Socialism and the Quest for Nuclear Power 1939–1949 (Cambridge, 1993) ISBN 0-521-43804-7

[edit] Notes