Gerhard Hoffmann

Gerhard Hoffmann

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Gerhard Hoffmann was a German
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 nuclear physicist. During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, he contributed to the German nuclear energy project, also known as the Uranium Club.

Education


Hoffmann studied at the Georg-August-Universität Göttingen, the Universität Leipzig
University of Leipzig
The University of Leipzig , located in Leipzig in the Free State of Saxony, Germany, is one of the oldest universities in the world and the second-oldest university in Germany...

, and the Rheinische Friedrich-Wilhelms-Universität Bonn
University of Bonn
The University of Bonn is a public research university located in Bonn, Germany. Founded in its present form in 1818, as the linear successor of earlier academic institutions, the University of Bonn is today one of the leading universities in Germany. The University of Bonn offers a large number...

. He received his doctorate at Bonn, in 1906, under Walter Kaufmann
Walter Kaufmann (physicist)
Walter Kaufmann was a German physicist. He is most well known for his first experimental proof of the velocity dependence of mass, which was an important contribution to the development of modern physics, including special relativity.-Life:In 1890/91 he studied mechanical engineering at the...

. In 1908, he became Kaufmann’s teaching assistant at the Albertus-Universität Königsberg
University of Königsberg
The University of Königsberg was the university of Königsberg in East Prussia. It was founded in 1544 as second Protestant academy by Duke Albert of Prussia, and was commonly known as the Albertina....

, where he completed his Habilitation
Habilitation
Habilitation is the highest academic qualification a scholar can achieve by his or her own pursuit in several European and Asian countries. Earned after obtaining a research doctorate, such as a PhD, habilitation requires the candidate to write a professorial thesis based on independent...

 in pure and applied physics in 1911.

Career


In 1917, Hoffmann became an ausserordentlicher Professor (extraordinarius professor) and worked on precision measurement of radioactivity and research in cosmic rays. From 1928-1937, as successor to Gustav Hertz, he was ordentlicher Professor (ordinarius professor) at the Martin-Luther-Universität Halle-Wittenberg
University of Halle-Wittenberg
The Martin Luther University of Halle-Wittenberg , also referred to as MLU, is a public, research-oriented university in the cities of Halle and Wittenberg within Saxony-Anhalt, Germany...

. In 1937 he succeeded Peter Debye
Peter Debye
Peter Joseph William Debye FRS was a Dutch physicist and physical chemist, and Nobel laureate in Chemistry.-Early life:...

 and became ordinarius professor of experimental physics at the University of Leipzig, a position he held until his death in 1945.

In December 1938, the German chemists Otto Hahn
Otto Hahn
Otto Hahn FRS was a German chemist and Nobel laureate, a pioneer in the fields of radioactivity and radiochemistry. He is regarded as "the father of nuclear chemistry". Hahn was a courageous opposer of Jewish persecution by the Nazis and after World War II he became a passionate campaigner...

 and Fritz Strassmann
Fritz Strassmann
Friedrich Wilhelm "Fritz" Strassmann was a German chemist who, with Otto Hahn in 1938, identified barium in the residue after bombarding uranium with neutrons, which led to the interpretation of their results as being from nuclear fission...

 sent a manuscript to Naturwissenschaften
Die Naturwissenschaften
Naturwissenschaften is a monthly peer-reviewed scientific journal published by Springer on behalf of several learned societies.- History :...

reporting they had detected the element barium
Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with...

 after bombarding uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

 with neutrons; simultaneously, they communicated these results to Lise Meitner
Lise Meitner
Lise Meitner FRS was an Austrian-born, later Swedish, physicist who worked on radioactivity and nuclear physics. Meitner was part of the team that discovered nuclear fission, an achievement for which her colleague Otto Hahn was awarded the Nobel Prize...

, who had in July of that year fled to The Netherlands and then went to Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

. Meitner, and her nephew Otto Robert Frisch
Otto Robert Frisch
Otto Robert Frisch , Austrian-British physicist. With his collaborator Rudolf Peierls he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940.- Overview :...

, correctly interpreted these results as being nuclear fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

. Frisch confirmed this experimentally on 13 January 1939.

Paul Harteck
Paul Harteck
Paul Karl Maria Harteck was a German physical chemist. He was arrested by the allied British and American Armed Forces and incarcerated at Farm Hall for six months in 1945 under Operation Epsilon.-Education:Harteck studied chemistry at the University of Vienna and the Humboldt University of Berlin...

 was director of the physical chemistry department at the University of Hamburg
University of Hamburg
The University of Hamburg is a university in Hamburg, Germany. It was founded on 28 March 1919 by Wilhelm Stern and others. It grew out of the previous Allgemeines Vorlesungswesen and the Kolonialinstitut as well as the Akademisches Gymnasium. There are around 38,000 students as of the start of...

 and an advisor to the Heereswaffenamt (HWA, Army Ordnance Office). On 24 April 1939, along with his teaching assistant Wilhelm Groth
Wilhelm Groth
Wilhelm Groth was a German physical chemist. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club; his main activity was the development of centrifuges for the enrichment of uranium. After the war, he was a professor of physical chemistry at the...

, Harteck made contact with the Reichskriegsministerium (RKM, Reich Ministry of War) to alert them to the potential of military applications of nuclear chain reactions. Two days earlier, on 22 April 1939, after hearing a colloquium paper by Wilhelm Hanle
Wilhelm Hanle
Wilhelm Hanle was a German experimental physicist. He is known for the Hanle effect. During World War II, he made contributions to the German nuclear energy project, also known as the Uranium Club...

 on the use of uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

 fission
Nuclear fission
In nuclear physics and nuclear chemistry, nuclear fission is a nuclear reaction in which the nucleus of an atom splits into smaller parts , often producing free neutrons and photons , and releasing a tremendous amount of energy...

 in a Uranmaschine (uranium machine, i.e., nuclear reactor
Nuclear reactor
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Most commonly they are used for generating electricity and for the propulsion of ships. Usually heat from nuclear fission is passed to a working fluid , which runs through turbines that power either ship's...

), Georg Joos
Georg Joos
Georg Jakob Christof Joos was a German theoretical physicist. He wrote Lehrbuch der theoretischen Physik, first published in 1932 and one of the most influential theoretical physics textbooks of the 20th Century.-Education:Joos began his higher education in 1912 at the Technische Hochschule...

, along with Hanle, notified Wilhelm Dames, at the Reichserziehungsministerium
Reichserziehungsministerium
The Reichserziehungsministerium was officially known as the Reichsministerium für Wissenschaft, Erziehung und Volksbildung .-Background:...

(REM, Reich Ministry of Education), of potential military applications of nuclear energy. The communication was given to Abraham Esau
Abraham Esau
Robert Abraham Esau was a German physicist.After receipt of his doctorate from the University of Berlin, Esau worked at Telefunken, where he pioneered very high frequency waves used in radar, radio, and television, and he was president of the Deutscher Telefunken Verband...

, head of the physics section of the Reichsforschungsrat
Reichsforschungsrat
The Reichsforschungsrat was created in Germany in 1937 under the Education Ministry for the purpose of centralized planning of all basic and applied research, with the exception of aeronautical research...

(RFR, Reich Research Council) at the REM. On 29 April, a group, organized by Esau, met at the REM to discuss the potential of a sustained nuclear chain reaction
Nuclear chain reaction
A nuclear chain reaction occurs when one nuclear reaction causes an average of one or more nuclear reactions, thus leading to a self-propagating number of these reactions. The specific nuclear reaction may be the fission of heavy isotopes or the fusion of light isotopes...

. The group included the physicists Walther Bothe
Walther Bothe
Walther Wilhelm Georg Bothe was a German nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born....

, Robert Döpel
Robert Döpel
Georg Robert Döpel 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...

, Hans Geiger, Wolfgang Gentner
Wolfgang Gentner
Wolfgang Gentner was a German experimental nuclear physicist.Gentner received his doctorate in 1930 from the University of Frankfurt. From 1932 to 1935 he had a fellowship which allowed him to do postdoctoral research and study at Curie's Radium Institute at the University of Paris...

 (probably sent by Walther Bothe
Walther Bothe
Walther Wilhelm Georg Bothe was a German nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born....

), Wilhelm Hanle
Wilhelm Hanle
Wilhelm Hanle was a German experimental physicist. He is known for the Hanle effect. During World War II, he made contributions to the German nuclear energy project, also known as the Uranium Club...

, Gerhard Hoffmann, and Georg Joos
Georg Joos
Georg Jakob Christof Joos was a German theoretical physicist. He wrote Lehrbuch der theoretischen Physik, first published in 1932 and one of the most influential theoretical physics textbooks of the 20th Century.-Education:Joos began his higher education in 1912 at the Technische Hochschule...

; Peter Debye
Peter Debye
Peter Joseph William Debye FRS was a Dutch physicist and physical chemist, and Nobel laureate in Chemistry.-Early life:...

 was invited, but he did not attend. After this, informal work began at Göttingen by Joos, Hanle, and their colleague Reinhold Mannfopff; the group of physicists was known informally as the first Uranverein (Uranium Club) and formally as Arbeitsgemeinschaft für Kernphysik. The group’s work was discontinued in August 1939, when the three were called to military training.

The second Uranverein began after the HWA squeezed out the RFR of the REM and started the formal German nuclear energy project
German nuclear energy project
The German nuclear energy project, , was an attempted clandestine scientific effort led by Germany to develop and produce the atomic weapons during the events involving the World War II...

 under military auspices. The second Uranverein was formed on 1 September 1939, the day World War II began, and it had its first meeting on 16 September 1939. The meeting was organized by Kurt Diebner
Kurt Diebner
Kurt Diebner was a German nuclear physicist who is well known for directing and administrating the German nuclear energy project, a secretive program aiming to built weapon of mass destruction for the Nazi Germany during the course of World War II...

, former student of Hoffmann at the University of Halle and advisor to the HWA, and held in Berlin. The invitees included Walther Bothe
Walther Bothe
Walther Wilhelm Georg Bothe was a German nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born....

, Siegfried Flügge
Siegfried Flügge
Siegfried Flügge was a German theoretical physicist and made contributions to nuclear physics. He worked at the Kaiser-Wilhelm Institut für Chemie and worked in the German Uranverein...

, Hans Geiger, Otto Hahn
Otto Hahn
Otto Hahn FRS was a German chemist and Nobel laureate, a pioneer in the fields of radioactivity and radiochemistry. He is regarded as "the father of nuclear chemistry". Hahn was a courageous opposer of Jewish persecution by the Nazis and after World War II he became a passionate campaigner...

, Paul Harteck
Paul Harteck
Paul Karl Maria Harteck was a German physical chemist. He was arrested by the allied British and American Armed Forces and incarcerated at Farm Hall for six months in 1945 under Operation Epsilon.-Education:Harteck studied chemistry at the University of Vienna and the Humboldt University of Berlin...

, Gerhard Hoffmann, Josef Mattauch
Josef Mattauch
Josef Mattauch was a German physicist known for his work in the investigation of the isotopic abundances by mass spectrometry. He developed the Mattauch isobar rule in 1934.-Mattauch-Herzog geometry mass spectrometer:...

, and Georg Stetter
Georg Stetter
Georg Stetter was an Austrian-German nuclear physicist. Stetter was Director of the Second Physics Institute of the University of Vienna. He was a principal member of the German nuclear energy project, also known as the Uranium Club. In the latter years of World War II, he was also the Director...

. A second meeting was held soon thereafter and included Klaus Clusius
Klaus Clusius
Klaus Clusius was a German physical chemist from Breslau , Silesia. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club; he worked on isotope separation techniques and heavy water production...

, Robert Döpel
Robert Döpel
Georg Robert Döpel 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...

, Werner Heisenberg
Werner Heisenberg
Werner Karl Heisenberg was a German theoretical physicist who made foundational contributions to quantum mechanics and is best known for asserting the uncertainty principle of quantum theory...

, and Carl Friedrich von Weizsäcker
Carl Friedrich von Weizsäcker
Carl Friedrich Freiherr von Weizsäcker was a German physicist and philosopher. He was the longest-living member of the research team which performed nuclear research in Germany during the Second World War, under Werner Heisenberg's leadership...

. Also at this time, the Kaiser-Wilhelm Institut für Physik (KWIP, Kaiser Wilhelm Institute for Physics, after World War II the Max Planck Institute for Physics
Max Planck Institute for Physics
Max Planck Institute for Physics is a physics institute in Munich, Germany that specializes in High Energy Physics and Astroparticle physics. It is part of the Max-Planck-Gesellschaft and is also known as the Werner Heisenberg Institute, after its first director.It was founded as the Kaiser Wilhelm...

), in Berlin-Dahlem
Dahlem (Berlin)
Dahlem is a locality of the Steglitz-Zehlendorf borough in southwestern Berlin. Until Berlin's 2001 administrative reform it was a part of the former borough of Zehlendorf. Dahlem is one of the most affluent parts of the city and home to the main campus of the Free University of Berlin with the...

, was placed under HWA authority, with Diebner as the administrative director, and the military control of the nuclear research commenced.

Hoffmann made contributions to the Uranverein in the area of cyclotrons as a nuclear research tool. He was among the first in Germany to propose and arrange financing for the construction of a cyclotron. His arrangements in 1937 were through the Reichsforschungsrat
Reichsforschungsrat
The Reichsforschungsrat was created in Germany in 1937 under the Education Ministry for the purpose of centralized planning of all basic and applied research, with the exception of aeronautical research...

; the cyclotron would eventually be installed at the University of Leipzig. Hoffmann had gone to Siemens und Halske AG
Siemens AG
Siemens AG is a German multinational conglomerate company headquartered in Munich, Germany. It is the largest Europe-based electronics and electrical engineering company....

with a proposal on the design of a cyclotron; the project was appealing to Desiderius Flir and Gustav Hertz at Siemens. Walther Bothe
Walther Bothe
Walther Wilhelm Georg Bothe was a German nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born....

, Director of the Institut für Physik at the Kaiser-Wilhelm Institut für medizinische Forschung (Kaiser Wilhelm Institute for Medical Research; today, the Max-Planck Institut für medizinische Forschung
Max Planck Institute for Medical Research
The Max Planck Institute for Medical Research in Heidelberg, Germany, is a facility of the Max Planck Society for basic medical research. Since its foundation, six Nobel Prize laureates worked at the Institute: Otto Fritz Meyerhof , Richard Kuhn , Walther Bothe , André Michel Lwoff , Rudolf...

), in Heidelberg
Heidelberg
-Early history:Between 600,000 and 200,000 years ago, "Heidelberg Man" died at nearby Mauer. His jaw bone was discovered in 1907; with scientific dating, his remains were determined to be the earliest evidence of human life in Europe. In the 5th century BC, a Celtic fortress of refuge and place of...

, was concurrently a competitor for support and took a different design to Siemens. The construction of their cyclotron at Heidelberg was overseen by Wolfgang Gentner
Wolfgang Gentner
Wolfgang Gentner was a German experimental nuclear physicist.Gentner received his doctorate in 1930 from the University of Frankfurt. From 1932 to 1935 he had a fellowship which allowed him to do postdoctoral research and study at Curie's Radium Institute at the University of Paris...

.