Operation Epsilon
The operation Epsilon was an intelligence operation within the ALSOS mission towards the end of World War II. The aim of the operation was to provide the American and English allies with knowledge of the state of German nuclear physics research, in particular to clarify the question of how far Germany was able to build an atomic bomb.
As part of Operation Epsilon, ten German physicists were taken into custody shortly before the end of the war and interned for six months at the English country estate of Farm Hall near the village of Godmanchester , where their conversations were listened to and recorded.
prehistory
The German uranium project
In the uranium project , German scientists from various scientific research institutes from the German Reich worked together to research the possibilities of using nuclear energy. The uranium project was initially headed by the Heereswaffenamt and was primarily aimed at researching the possible military uses of this technology. Since 1942 no longer believed in the rapid realization of military use, the project was placed under the administrative direction of the Reich Research Council from May 1942 and the focus of research was shifted to the question of the basic structure of a nuclear reactor. The project was scientifically managed by Werner Heisenberg , the director of the Kaiser Wilhelm Institute for Physics in Berlin-Dahlem , where the large-scale tests for the construction of a uranium reactor were initially carried out in a bunker laboratory.
From the summer of 1943, the Kaiser Wilhelm Institute for Physics was gradually relocated to Hechingen and Haigerloch in what is now Baden-Württemberg, as the Berlin location had become too dangerous due to the threat of bombing. At the same time, the Kaiser Wilhelm Institute for Chemistry, headed by Otto Hahn , was relocated to the neighboring town of Tailfingen . The scientists involved tried to construct the first German nuclear reactor in a rock cellar under the Haigerloch castle church . The imminent success was prevented by the invasion of French troops. Werner Heisenberg had the uranium cubes used buried in a field and the heavy water transferred to the tanks of a former textile factory in order to keep these valuable resources safe from the Allies and to be able to continue to use them after the end of the war. Shortly afterwards, Carl Friedrich von Weizsäcker and Karl Wirtz sank the research documents hidden in a soldered metal canister into the sump behind von Weizsäcker's house.
The ALSOS mission
Operation Epsilon was part of the ALSOS mission as part of the US Secret Service's Manhattan Project . The aim of the mission, carried out from the end of 1943 to the end of 1945, was to enable the Allies to assess the nuclear threat emanating from Germany and then to neutralize it if necessary. The aim was to find out whether there was a German project to build an atomic bomb, which scientists were involved, how far the research had progressed and how its completion could be prevented.
The ALSOS command under the military direction of Colonel Boris Pash had set up a main base in Heidelberg. After the secret service succeeded in identifying the leading scientists involved in the German uranium project and locating their respective whereabouts, they were taken into custody by troops from the ALSOS mission.
The scientists were arrested and interrogated
Most of the scientists were arrested between April 23 and April 25 in Hechingen and Tailfingen by forces from the ALSOS mission and then brought to Heidelberg for the first interrogation.
On May 1, 1945, Carl Friedrich von Weizsäcker, Karl Wirtz, Erich Bagge , Horst Korsching , Otto Hahn and Max von Laue were brought from Heidelberg to France by bus. The bus drove under military escort over Metz, Gravelotte, Verdun and Valmy. In Reims, the scientists, guarded by US soldiers armed with submachine guns, were given a tour of the cathedral . Since the scientists were not members of the military, they were taken into military custody by the US Army, but did not have the status of prisoners of war. The overseers and guards always referred to them as guests .
Werner Heisenberg had already bought the former Petermann house of the painter Lovis Corinth on Walchensee in 1939 , in which his wife and the couple's children lived during the war, in order to avoid the bombing of Leipzig. On the morning of April 20, 1945, Heisenberg left Hechingen to cycle the approx. 270 km long route to his family. He had issued himself the necessary travel permit and marching orders. On May 2, US Colonel Boris Pash , the military head of the ALSOS mission, had Heisenberg's house in Urfeld surrounded with tracked vehicles, tanks and jeeps and Heisenberg captured. After an interrogation by Pash, Heisenberg was brought to Heidelberg the next day, where he was interrogated in detail about the status of the German uranium project by the scientific director of the ALSOS mission, the Dutch atomic physicist Samuel Abraham Goudsmit . During the interrogation, Goudsmit Heisenberg, when asked about the state of American atomic bomb research, deliberately gave the wrong information that the Americans had carried out this project in favor of more practical research, e.g. B. for the development of radar, neglected.
On May 7, 1945, the scientists left Reims by plane and were flown to Versailles via a stopover in Paris . They were housed in the shabby Château du Grand Chesnay in nearby Le Chesnay , which the Americans used as an internment camp.
On May 9, 1945 Werner Heisenberg and Kurt Diebner , who had been brought there in a jeep, arrived at the Château du Grand Chesnay. While Heisenberg was greeted in a friendly manner by his former colleagues and friends von Weizsäcker and Wirtz, the members of the Diebner group disapproved of the fact that they accused him of allowing himself to be taken over by the SS as a consultant for the Army Weapons Office .
The scientists taken into custody and their relation to the uranium project
| Surname | Life dates | function | |
|---|---|---|---|
| Erich Bagge | * May 30, 1912 in Neustadt near Coburg † June 5, 1996 in Kiel |
Bagge was a research fellow in the German uranium project at the Kaiser Wilhelm Institute for Physics. Between 1941 and 1943 he developed the isotope lock for the enrichment of uranium. | |
|
Kurt Diebner | * May 13, 1905 in Obernessa † July 13, 1964 in Oberhausen |
From 1939, Diebner was head of the newly established atomic physics department at the Wa FI (physics) group at the Heereswaffenamt in Kummersdorf. From January 1940 to September 1942 he was managing director of the Kaiser Wilhelm Institute for Physics, which had been partially confiscated by the Army Weapons Office for the uranium project. From 1939 he set up his own research group for atomic physics at the Heeresversuchsstelle Gottow of the Heereswaffenamt. |
|
Walther Gerlach | * August 1, 1889 in Biebrich am Rhein † August 10, 1979 in Munich |
From 1943 Gerlach was head of the physics department and the working group for nuclear physics in the Reich Research Council. From 1944, Hermann Görings was involved in the uranium project as an authorized representative for nuclear physics . |
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|
Otto Hahn | * March 8, 1879 in Frankfurt am Main † July 28, 1968 in Göttingen |
From 1928 Otto Hahn was director of the Kaiser Wilhelm Institute for Chemistry, which was involved in the uranium project. In December 1938, together with his assistant Fritz Strassmann, he discovered the nuclear fission of the heavy element uranium , for which he was awarded the Nobel Prize for Chemistry in 1944 in 1945 . |
|
Paul Harteck | * July 20, 1902 in Vienna † January 22, 1985 in Santa Barbara |
From 1934 Harteck was director of the Institute for Physical Chemistry and professor at the University of Hamburg. With his institute he was involved in the uranium project. |
|
Werner Heisenberg | * December 5, 1901 in Würzburg † February 1, 1976 in Munich |
Heisenberg was director of the Kaiser Wilhelm Institute for Physics and scientific director of the uranium project from 1942 to 1945. The agents of the ALSOS mission considered him a key figure in clearing up their questions. |
| Horst Korsching | * August 12, 1912 in Danzig † March 21, 1998 in Hildesheim |
Korsching worked under the direction of Kurt Diebner and Werner Heisenberg as a research assistant at the Kaiser Wilhelm Institute for Physics on uranium enrichment. He was considered a specialist in isotope separation through thermal diffusion . | |
|
Max von Laue | * October 9, 1879 in Pfaffendorf † April 24, 1960 in West Berlin |
Max von Laue had worked at the Kaiser Wilhelm Institute for Physics since 1919, and from 1922 as deputy director under Albert Einstein , for whom he campaigned during the Nazi era. In 1943 he retired early. |
|
Carl Friedrich Freiherr von Weizsäcker | * June 28, 1912 in Kiel † April 28, 2007 in Söcking (Starnberg) |
After his habilitation, von Weizsäcker worked as a research assistant at the Kaiser Wilhelm Institute for Physics from 1936. From 1940 to 1942 he worked on the German uranium project, from 1942 to 1944 he held the chair for theoretical physics at the Reich University of Strasbourg . |
| Karl Wirtz | * April 24, 1910 in Cologne † February 12, 1994 in Karlsruhe |
From 1937, Karl Wirtz worked in Werner Heisenberg's group at the Kaiser Wilhelm Institute for Physics in Berlin. From 1941 he was a lecturer at the University of Berlin. From 1944 he was head of the experimental department in the German uranium project. |
Staying at Farm Hall
Finally, the physicists were brought from France to the English country estate of Farm Hall near Cambridge. Although the scientists had not been informed of the reason for their arrest and internment, they suspected, based on the fact that all but one of them had been actively involved in the German uranium project, that the reason for the arrest lay in their research.
The interned scientists assumed that they were ahead of the Allies in the field of applied nuclear fission, but this was not the case. They were only allowed to have very limited contact with their families who had stayed behind in Germany, and they were left completely in the dark about the duration and also about the question of whether they would be allowed to return to Germany at all.
A group of eight people, including Peter Ganz , led by Major Th. H. Rittner, was responsible for listening, recording, transcribing and translating (so-called Farm Hall transcripts ). Only relevant technical or political information, around ten percent of all intercepted words, was recorded, transcribed and translated. The recordings were made with six to eight machines on shellac- coated metal discs. After transcription , the discs were erased and reused. The transcripts were sent to Washington Project Leader , General Leslie R. Groves , in the form of 24 reports on more than 250 pages.
Reaction to the atomic bomb drop in Hiroshima
On August 6, 1945, the interned physicists were told that the atomic bomb had been dropped on Hiroshima by their English guards . The scientists didn't believe the guards, and it wasn't until they heard an official statement at 9:00 p.m. that evening that they realized the news was true, which upset them completely. A professional discourse arose between the physicists in which they discussed which physical reaction principle, in particular which quantity of which element the Allies needed to manufacture this bomb and which methods they had successfully used to manufacture it.
Heisenberg was finally asked by his colleagues to give a lecture on this technical problem, which took place on August 14, 1945 and in which he focused primarily on the question of the amount of uranium used, the possible ignition mechanism of the bomb and the effects of the bomb explosion he suspected received.
reception
In 1962, the former head of the American atomic bomb project, General Leslie R. Groves , published his memoir. Only then did it become public that the German scientists interned in Farm Hall had been wiretapped and that copies of the recordings made existed.
Both Groves and Goudsmit expressed the opinion in their publications that the German scientists had not built the atomic bomb because of moral concerns but because of technical inadequacies.
In an appeal to the British Lord Chancellor in November 1991, around twenty renowned scientists demanded the release of the recordings from Farm Hall. The action was initiated by the physicists Nicholas Kurti and Rudolf Peierls and the historian Margaret Gowing . The presidents of the Royal Society and the British Academy were among the signatories . A few months later, the Public Record Office published a 212-page transcript of the sound recordings made in Farm Hall. A short time later, the US National Archives also published a protocol that was more extensive than the British version. However, neither the recordings themselves nor the original German version were published.
In retrospect, the publication made it clear that the physicist Goudsmit must also have known the content of the protocols when he wrote his book on the ALSOS mission in 1947.
In his biography , Groves expressed his conviction that the moral concerns later expressed by Heisenberg and von Weizsäcker , among others , about the construction of an atomic bomb were a post-festum argument , that is, a pretended reason. Heisenberg had incorrectly calculated the amount of critical mass of uranium-235 required for an atomic bomb in the years before in tons instead of kilograms, so that enough material for a bomb could not be produced in time before the end of the war.
The events surrounding the German uranium project, Operation Epsilon and the internment in Farm Hall are dealt with in the two-part television film End of Innocence by director Frank Beyer . The film was shot on various original locations in 1990/91.
See also
literature
- Leslie R. Groves : Now it can be told - The story of the Manhattan Project. Da Capo Press, 1962.
- Paul Lawrence Rose: Heisenberg and the Nazi Atomic bomb project: a study in German culture. University of California Press, Berkeley 1998.
- Jeremy Bernstein , David C. Cassidy : Hitler's Uranium Club: The Secret Recordings at Farm Hall , American Institute of Physics 1996
- David C. Cassidy: Farm Hall and the German atomic bomb project of world war II. A dramatic history , Springer 2017
- Dieter Hoffmann : Operation Epsilon. The Farm Hall Protocols or The Allies Fear of the German Atomic Bomb , Rowohlt 1993, ISBN 3-87134-082-0 (German reverse translation of the protocols by Wilfried Sczepan).
- Dieter Hoffmann Farm Hall tapes: Operation Epsilon: The secret service files on the internment of the German nuclear physicists in Farm Hall in England are open , Physikalische Blätter, Volume 48, 1992, pp. 898–993, doi : 10.1002 / phbl.19920481205
- Mark Walker , Helmut Rechenberg Farm Hall tapes: About the uranium bomb: Werner Heisenberg's listened to lecture on August 14, 1945 in Farm Hall , Physikalische Blätter, Volume 48, 1992, pp. 994-1001, doi : 10.1002 / phbl.19920481206
- Charles Frank (editor, foreword): Operation Epsilon. The Farm Hall Protocols , University of California Press, Institute of Physics , 1993
- Richard von Schirach : The night of the physicists. Heisenberg, Hahn, Weizsäcker and the German bomb . Berenberg Verlag, Berlin 2012
Web links
Individual evidence
- ^ Helmut Rechenberg: Werner Heisenberg and the research program of the Kaiser Wilhelm Institute for Physics (1940-1948) In: Bernhard vom Brocke, Hubert Laitko: The Kaiser Wilhelm / Max Planck Society and its institutes - The Harnack principle . De Gruyter-Verlag, 1996, pp. 245-262
- ↑ a b c After the end - From Haigerloch to Urfeld In: Richard von Schirach: The night of the physicists - Heisenberg, Hahn, Weizsäcker and the German atomic bomb. 5th edition, Berenberg-Verlag, Berlin 2013, ISBN 978-3-937834-54-2 , pp. 15-22
- ↑ a b c d e f g h i Mark Walker: Self-reflection of German atomic physicists - The Farm Hall protocols and the emergence of new legends about the “German atomic bomb” . In: Vierteljahrshefte für Zeitgeschichte, Volume 41, Issue 4 (October 1993), pp. 519–542 ( PDF )
- ↑ a b After the end - interrogation in Heidelberg In: Richard von Schirach: The night of the physicists - Heisenberg, Hahn, Weizsäcker and the German atomic bomb. 5th edition, Berenberg-Verlag, Berlin 2013, ISBN 978-3-937834-54-2 , pp. 23-26
- ↑ Gerhard Oexle: Hahn, Heisenberg and the others: Notes on 'Copenhagen', 'Farm Hall' and 'Göttingen' In: Carola Sachse (Ed.) On behalf of the Presidential Commission of the Max Planck Society for the Promotion of Science. V .: Preprints from the research program “History of the Kaiser Wilhelm Society under National Socialism”, pp. 4–49
- ↑ a b c After the end - ten physicists wander through Europe In: Richard von Schirach: The night of the physicists - Heisenberg, Hahn, Weizsäcker and the German atomic bomb. 5th edition, Berenberg-Verlag, Berlin 2013, ISBN 978-3-937834-54-2 , pp. 26-40
- ↑ Leslie R. Groves: Now I can speak: The story of the first atomic bomb , Cologne, Berlin: Kiepenheuer & Witsch 1965 (Original: Now It Can Be Told: The Story of the Manhattan Project. Paperback, Da Capo Press, 1962, reissue 1983, ISBN 0-306-80189-2 )
- ↑ Samuel Abraham Goudsmit: Alsos. The failure in German science. Sigma Books, London 1947.
- ↑ Cockfight in the laboratory. In: Der Spiegel. 14/1991 of April 1, 1991, pp. 222-224