Walther Bothe Walther Wilhelm Georg Bothe ( 8 January 1891 – 8 February 1957 ) was a German nuclear physicist , who shared the Nobel Prize in Physics in 1954 with Max Born . In 1913 , he joined the newly created Laboratory for Radioactivity at the Reich Physical and Technical Institute ( PTR ) , where he remained until 1930 , the latter few years as the director of the laboratory . He served in the military during World War I from 1914 , and he was a prisoner of war of the Russians , returning to Germany in 1920 . Upon his return to the laboratory , he developed and applied coincidence methods to the study of nuclear reactions , the Compton effect , cosmic rays , and the wave - particle duality of radiation , for which he would receive the Nobel Prize in Physics in 1954 . In 1930 he became a full professor and director of the physics department at the University of Giessen . In 1932 , he became director of the Physical and Radiological Institute at the University of Heidelberg . He was driven out of this position by elements of the " deutsche Physik " movement . To preclude his emigration from Germany , he was appointed director of the Physics Institute of the Kaiser Wilhelm Institute for Medical Research ( KWImF ) in Heidelberg . There , he built the first operational cyclotron in Germany . Furthermore , he became a principal in the German nuclear energy project , also known as the Uranium Club , which was started in 1939 under the supervision of the Army Ordnance Office . In 1946 , in addition to his directorship of the Physics Institute at the KWImf , he was reinstated as a professor at the University of Heidelberg . From 1956 to 1957 , he was a member of the Nuclear Physics Working Group in Germany . In the year after Bothe ' s death , his Physics Institute at the KWImF was elevated to the status of a new institute under the Max Planck Society and it then became the Max Planck Institute for Nuclear Physics . Its main building was later named Bothe laboratory . Education . Bothe was born to Fredrich Bothe and Charlotte Hartung . From 1908 to 1912 , Bothe studied at the " Friedrich - Wilhelms - Universität " ( today , the " Humboldt - Universität zu Berlin " ) . In 1913 , he was Max Planck ' s teaching assistant . He was awarded his doctorate , in 1914 , under Planck . Career . Early years . In 1913 , Bothe joined the Physikalisch - Technische Reichsanstalt ( PTR , Reich Physical and Technical Institute ; today , the " Physikalisch - Technische Bundesanstalt " ) , where he stayed until 1930 . Hans Geiger had been appointed director of the new Laboratory for Radioactivity there in 1912 . At the PTR , Bothe was an assistant to Geiger from 1913 to 1920 , a scientific member of Geiger ' s staff from 1920 to 1927 , and from 1927 to 1930 he succeeded Geiger as director of the Laboratory for Radioactivity . In May 1914 , Bothe volunteered for service in the German cavalry . He was taken prisoner by the Russians and incarcerated in Russia for five years . While there , he learned the Russian language and worked on theoretical physics problems related to his doctoral studies . He returned to Germany in 1920 , with a Russian bride . Upon his return from Russia , Bothe continued his employment at the PTR under Hans Geiger in the Laboratory for Radioactivity there . In 1924 , Bothe published on his coincidence method . Then and in the following years , he applied this method to the experimental study of the nuclear reactions , the Compton effect , and the wave - particle duality of light . Bothe ' s coincidence method and his applications of it earned him the Nobel Prize in Physics in 1954 . In 1925 , while still at the PTR , Bothe became a " Privatdozent " at the University of Berlin , which means that he had completed his Habilitation , and , in 1929 , he became an " ausserordentlicher Professor " ( extraordinarius professor ) there . In 1927 , Bothe began the study of the transmutation of light elements through bombardment with alpha particles . From a joint investigation with H . Fränz and Heinz Pose in 1928 , Bothe and Fränz correlated reaction products of nuclear interactions to nuclear energy levels . In 1929 , in collaboration with Werner Kolhörster and Bruno Rossi who were guests in Bothe ' s laboratory at the PTR , Bothe began the study of cosmic rays . The study of cosmic radiation would be conducted by Bothe for the rest of his life . In 1930 , he became an " ordentlicher Professor " ( ordinarius professor ) and director of the physics department at the " Justus Liebig - Universität Gießen " . That year , working with Herbert Becker , Bothe bombarded beryllium , boron , and lithium with alpha particles from polonium and observed a new form of penetrating radiation . In 1932 , James Chadwick identified this radiation as the neutron . Heidelberg . In 1932 , Bothe had succeeded Philipp Lenard as Director of the " Physikalische und Radiologische Institut " ( Physical and Radiological Institute ) at the University of Heidelberg . It was then that Rudolf Fleischmann became a teaching assistant to Bothe . When Adolf Hitler became Chancellor of Germany on 30 January 1933 , the concept of " Deutsche Physik " took on more favor as well as fervor ; it was anti - Semitic and anti - theoretical physics , especially modern physics , including quantum mechanics and both atomic and nuclear physics . As applied in the university environment , political factors took priority over the historically applied concept of scholarly ability , even though its two most prominent supporters were the Nobel Laureates in Physics Philipp Lenard and Johannes Stark . Supporters of " Deutsche Physik " launched vicious attacks against leading theoretical physicists . While Lenard was retired from the University of Heidelberg , he still had significant influence there . In 1934 , Lenard had managed to get Bothe relieved of his directorship of the Physical and Radiological Institute at the University of Heidelberg , whereupon Bothe was able to become the Director of the " Institut für Physik " ( Institute for Physics ) of the " Kaiser - Wilhelm Institut für medizinische Forschung " ( KWImF , Kaiser Wilhelm Institute for Medical Research ; today , the Max - Planck Institut für medizinische Forschung ) , in Heidelberg , replacing Karl W . Hauser , who had recently died . Ludolf von Krehl , Director of the KWImF , and Max Planck , President of the Kaiser - Wilhelm Gesellschaft ( KWG , Kaiser Wilhelm Society , today the Max Planck Society ) , had offered the directorship to Bothe to ward off the possibility of his emigration . Bothe held the directorship of the Institute for Physics at the KWImF until his death in 1957 . While at the KWImF , Bothe held an honorary professorship at the University of Heidelberg , which he held until 1946 . Fleischmann went with Bothe and worked with him there until 1941 . To his staff , Bothe recruited scientists including Wolfgang Gentner ( 1936 – 1945 ) , Heinz Maier - Leibnitz ( 1936 - ? ) - who had done his doctorate with the Nobel Laureate James Franck and was highly recommend by Robert Pohl and Georg Joos , and Arnold Flammersfeld ( 1939 – 1941 ) . Also included on his staff were Peter Jensen and Erwin Fünfer . In 1938 , Bothe and Gentner published on the energy dependence of the nuclear photo - effect . This was the first clear evidence that nuclear absorption spectra are accumulative and continuous , an effect known as the dipolar giant nuclear resonance . This was explained theoretically a decade later by physicists J . Hans D . Jensen , Helmut Steinwedel , Peter Jensen , Michael Goldhaber , and Edward Teller . Also in 1938 , Maier - Leibniz built a Wilson cloud chamber . Images from the cloud chamber were used by Bothe , Gentner , and Maier - Leibniz to publish , in 1940 , the " Atlas of Typical Cloud Chamber Images " , which became a standard reference for identifying scattered particles . 1st German Cyclotron . By the end of 1937 , the rapid successes Bothe and Gentner had with the building and research uses of a Van de Graaff generator had led them to consider building a cyclotron . By November , a report had already been sent to the President of the " Kaiser - Wilhelm Gesellschaft " ( KWG , Kaiser Wilhelm Society ; today , the Max Planck Society ) , and Bothe began securing funds from the " Helmholtz - Gesellschaft " ( Helmholtz Society ; today , the " Helmholtz Association of German Research Centres " ) , the " Badischen Kultusministerium " ( Baden Ministry of Culture ) , " I . G . Farben " , the KWG , and various other research oriented agencies . Initial promises led to ordering a magnet from " Siemens " in September 1938 , however , further financing then became problematic . In these times , Gentner continued his research on the nuclear photoeffect , with the aid of the Van de Graaff generator , which had been upgraded to produce energies just under 1 MeV . When his line of research was completed with the Li ( p , gamma ) and the B ( p , gamma ) reactions , and on the nuclear isomer Br , Gentner devoted his full effort to the building of the planned cyclotron . In order to facilitate the construction of the cyclotron , at the end of 1938 and into 1939 , with the help of a fellowship from the " Helmholtz - Gesellschaft " , Gentner was sent to Radiation Laboratory of the University of California ( today , the Lawrence Berkeley National Laboratory ) in Berkeley , California . As a result of the visit , Gentner formed a cooperative relationship with Emilio G . Segrè and Donald Cooksey . After the armistice between France and Germany in the summer of 1940 , Bothe and Gentner received orders to inspect the cyclotron Frédéric Joliot - Curie had built in Paris . While it had been built , it was not yet operational . In September 1940 , Gentner received orders to form a group to put the cyclotron into operation . Hermann Dänzer from the University of Frankfurt participated in this effort . While in Paris , Gentner was able to free both Frédéric Joliot - Curie and Paul Langevin , who had been arrested and detained . At the end of the winter of 1941 / 1942 , the cyclotron was operational with a 7 - MeV beam of deuterons . Uranium and thorium were irradiated with the beam , and the byproducts were sent to Otto Hahn at the " Kaiser - Wilhelm Institut für Chemie " ( KWIC , Kaiser Wilhelm Institute for Chemistry , today , the Max Planck Institute for Chemistry ) , in Berlin . In mid - 1942 , Gentner ' s successor in Paris , was Wolfgang Riezler from Bonn . It was during 1941 that Bothe had acquired all the necessary funding to complete construction of the cyclotron . The magnet was delivered in March 1943 , and the first beam of deuteron was emitted in December . The inauguration ceremony for the cyclotron was held on 2 June 1944 . While there had been other cyclotrons under construction , Bothe ' s was the first operational cyclotron in Germany . Uranium Club . The German nuclear energy project , also known as the " Uranverein " ( Uranium Club ) , began in the spring of 1939 under the auspices of the " Reichsforschungsrat " ( RFR , Reich Research Council ) of the " Reichserziehungsministerium " ( REM , Reich Ministry of Education ) . By 1 September , the " Heereswaffenamt " ( HWA , Army Ordnance Office ) squeezed out the RFR and took over the effort . Under the control of the HWA , the " Uranverein " had its first meeting on 16 September . The meeting was organized by Kurt Diebner , advisor to the HWA , and held in Berlin . The invitees included Walther Bothe , Siegfried Flügge , Hans Geiger , Otto Hahn , Paul Harteck , Gerhard Hoffmann , Josef Mattauch , and Georg Stetter . A second meeting was held soon thereafter and included Klaus Clusius , Robert Döpel , Werner Heisenberg , and Carl Friedrich von Weizsäcker . With Bothe being one of the principals , Wolfgang Gentner , Arnold Flammersfeld , Rudolf Fleischmann , Erwin Fünfer , and Peter Jensen were soon drawn into work for the " Uranverein " . Their research was published in the " Kernphysikalische Forschungsberichte " ( " Research Reports in Nuclear Physics " ) ; see below the section " Internal Reports " . For the " Uranverein " , Bothe , and up to 6 members from his staff by 1942 , worked on the experimental determination of atomic constants , the energy distribution of fission fragments , and nuclear cross sections . Bothe ' s experimental results on the absorption of neutrons in graphite were central in the German decision to favor heavy water as a neutron moderator . By late 1941 it was apparent that the nuclear energy project would not make a decisive contribution to ending the war effort in the near term . HWA control of the " Uranverein " was relinquished to the RFR in July 1942 . The nuclear energy project thereafter maintained its " kriegswichtig " ( important for the war ) designation and funding continued from the military . However , the German nuclear power project was then broken down into the following main areas : uranium and heavy water production , uranium isotope separation , and the " Uranmaschine " ( uranium machine , i . e . , nuclear reactor ) . Also , the project was then essentially split up between nine institutes , where the directors dominated the research and set their own research agendas . Bothe ' s " Institut für Physik " was one of the nine institutes . The other eight institutes or facilities were : the Institute for Physical Chemistry at the Ludwig Maximilian University of Munich , the HWA " Versuchsstelle " ( testing station ) in Gottow , the " Kaiser - Wilhelm - Institut für Chemie " , the Physical Chemistry Department of the University of Hamburg , the Kaiser - Wilhelm - Institut für Physik " , the Second Experimental Physics Institute at the Georg - August University of Göttingen , the Auergesellschaft , and the " II . Physikalisches Institut " at the University of Vienna . Post WW II . From 1946 , to 1957 , in addition to his position at the KWImF , Both was an " ordentlicher Professor " ( ordinarius professor ) at the University of Heidelberg . At the end of World War II , the Allies had seized the cyclotron at Heidelberg . In 1949 , its control was returned to Bothe . During 1956 and 1957 , Bothe was a member of the " Arbeitskreis Kernphysik " ( Nuclear Physics Working Group ) of the " Fachkommission II " Forschung und Nachwuchs " " ( Commission II " Research and Growth " ) of the " Deutschen Atomkommission " ( DAtK , German Atomic Energy Commission ) . Other members of the Nuclear Physics Working Group in both 1956 and 1957 were : Werner Heisenberg ( chairman ) , Hans Kopfermann ( vice - chairman ) , Fritz Bopp , Wolfgang Gentner , Otto Haxel , Willibald Jentschke , Heinz Maier - Liebnitz , Josef Mattauch , Wolfgang Riezler , Wilhelm Walcher , and Carl Friedrich von Weizsäcker . Wolfgang Paul was also a member of the group during 1957 . At the end of 1957 , Gentner was in negotiations with Otto Hahn , President of the " Max - Planck Gesellschaft " ( MPG , Max Planck Society , successor of the " Kaiser - Wilhelm Gesellschaft " ) , and with the Senate of the MPG to establish a new institute under their auspices . Essentially , Walther Bothe ' s " Institut für Physik " at the " Max - Planck Institut für medizinische Forschung " , in Heidelberg , was to be spun off to become a full fledged institute of the MPG . The decision to proceed was made in May 1958 . Gentner was named the director of the " Max - Planck Institut für Kernphysik " ( MPIK , Max Planck Institute for Nuclear Physics ) on 1 October , and he also received the position as an " ordentlicher Professor " ( ordinarius professor ) at the University of Heidelberg . Bothe had not lived to see the final establishment of the MPIK , as he had died in February of that year . Bothe was a German patriot who did not give excuses for his work with the " Uranverein " . However , Bothe ' s impatience with National Socialist policies in Germany brought him under suspicion and investigation by the Gestapo . Personal . As a result of his incarceration in Russia during World War I as a prisoner of war , he met Barbara Below , whom he married in 1920 . They had two children . She preceded him in death by some years . Bothe was an accomplished painter and musician ; he played the piano . Honors . Bothe was awarded a number of honors : 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 .