Willibald Jentschke
Encyclopedia
Willibald Jentschke was an Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...

n-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...

 experimental nuclear physicist
Nuclear physics
Nuclear physics is the field of physics that studies the building blocks and interactions of atomic nuclei. The most commonly known applications of nuclear physics are nuclear power generation and nuclear weapons technology, but the research has provided application in many fields, including those...

. During World War II, he made contributions to the German nuclear energy project. After World War II, he emigrated to the United States to work at Wright-Patterson Air Force Base, in Ohio, for the Air Force Materiel Command. In 1950, he became a professor at the University of Illinois at Urbana-Champaign, where he became director of the Cyclotron Laboratory there in 1951. In 1956, he became a professor of physics at the University of Hamburg and spearheaded the effort to build the 7.5 GeV electron synchrotron DESY, the foundation of which was in December 1959. He was director of DESY for 10 years. In 1971, he became Director General of CERN Laboratory I for the next five years. He retired from the University of Hamburg in 1980.

Education

Jentschke studied physics at the University of Vienna
University of Vienna
The University of Vienna is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world...

, from 1930 to 1936. He received his doctorate under 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...

 in 1935.

Career

From 1937 to 1942, Jentschke was a teaching assistant to Georg Stetter at the University of Vienna
University of Vienna
The University of Vienna is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world...

. From 1942 to 1945, he was a lecturer at the University of Vienna. During World War II, Jentschke was also (Scientific Assistant) at the II. Physikalisches Institut der Universität, Wien (Second Physics Institute of the University of Vienna
University of Vienna
The University of Vienna is a public university located in Vienna, Austria. It was founded by Duke Rudolph IV in 1365 and is the oldest university in the German-speaking world...

), where Georg Stetter was the director. One of Jentschke’s colleagues there was Josef Schintlmeister
Josef Schintlmeister
Josef Schintlmeister was an Austrian-German nuclear physicist and alpinist from Radstadt. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club. After World War II, he was sent Russia to work on the Soviet atomic bomb project. After he returned to...

. The Institute did research on transuranic elements and measurement of nuclear constants, in collaboration with the Institut für Radiumforschung (Institute for Radium Research
Institute for Radium Research, Vienna
The Institute for Radium Research was an Austrian research institute associated with the Austrian Academy of Sciences, Vienna. The Institute's researchers won multiple Nobel Prizes...

) of the Österreichischen Adademie der Wissenschaften (Austrian Academy of Sciences). This work was done under the 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...

, also known as the Uranverein (Uranium Club); see, for example, the publications cited below under Internal Reports.

In 1939, John Archibald Wheeler
John Archibald Wheeler
John Archibald Wheeler was an American theoretical physicist who was largely responsible for reviving interest in general relativity in the United States after World War II. Wheeler also worked with Niels Bohr in explaining the basic principles behind nuclear fission...

 and Niels Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...

 proposed the liquid drop model of 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...

. Their work suggested that 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...

 235 was responsible for thermal neutron fission. This was borne out by the work of Eugene T. Booth
Eugene T. Booth
Eugene Theodore Booth was an American nuclear physicist. He was a member of the historic Columbia University team which made the first demonstration of nuclear fission in the United States. During the Manhattan Project, he worked on gaseous diffusion for isotope separation...

, John R. Dunning
John R. Dunning
John Ray Dunning was an American physicist who played key roles in the development of the atomic bomb. He specialized in neutron physics and did pioneering work in gaseous diffusion for isotope separation...

, A. V. Grosse, and Alfred O. C. Nier
Alfred O. C. Nier
Alfred Otto Carl Nier was an American physicist who pioneered the development of mass spectrometry and used it in innovative ways to establish some major scientific results.-Early career:...

, which was submitted for publication in the spring of 1940. Jentschke, F. Prankl, and F. Hernegger also substantiated the Bohr-Wheeler claims shortly after the American work by observing the phenomenon in an isotope of thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....

, thorium 230
Isotopes of thorium
Although thorium has 6 naturally occurring isotopes, none of these isotopes are stable; however, one isotope, 232Th, is relatively stable, with a half-life of 14.05 billion years, considerably longer than the age of the earth, and even slightly longer than the generally-accepted age of the...

.

From 1946 to 1947, Jentschke was a lecturer at the University of Innsbruck.

Near the close and after the end of World War II in Europe, the Russians and the Western powers had programs to foster technology transfer and exploit German technical specialists. For example, the U.S. had Operation Paperclip
Operation Paperclip
Operation Paperclip was the Office of Strategic Services program used to recruit the scientists of Nazi Germany for employment by the United States in the aftermath of World War II...

  and the Russians had trophy brigades advancing with their military forces. In the area of atomic technology, the U.S. had Operation Alsos
Operation Alsos
Operation Alsos was an effort at the end of World War II by the Allies , branched off from the Manhattan Project, to investigate the German nuclear energy project, seize German nuclear resources, materials and personnel to further American research and to prevent their capture by the Soviets, and...

 and the Russians had their version. While operational aspects of the Russian operation were modeled after the trophy brigades, a more refined approach was warranted for the exploitation of German atomic related facilities, intellectual materials, and scientific personnel. This was rectified with a decree in late 1944 and the formation of specialize exploitation teams in early 1945 under the Russian Alsos
Russian Alsos
The Russian Alsos was an operation which took place in early 1945 in Germany, Austria, and Czechoslovakia, and whose objectives were the exploitation of German atomic related facilities, intellectual materials, materiel resources, and scientific personnel for the benefit of the Soviet atomic bomb...

, which had broader objectives, which included wholesale relocation of scientific facilities to the Soviet Union.

Jentschke emigrated to the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 under Operation Paperclip
Operation Paperclip
Operation Paperclip was the Office of Strategic Services program used to recruit the scientists of Nazi Germany for employment by the United States in the aftermath of World War II...

, where he worked at the Air Force Materiel Command
Air Force Materiel Command
Air Force Materiel Command is a major command of the United States Air Force. AFMC was created July 1, 1992 through the reorganization of Air Force Logistics Command and Air Force Systems Command....

 (today, the Air Force Logistics Command
Air Force Logistics Command
Air Force Logistics Command was a United States Air Force command. Its headquarters was located at Wright-Patterson Air Force Base, Ohio...

 after merger with the Air Force Systems Command
Air Force Systems Command
Air Force Systems Command is a former United States Air Force command. Its headquarters was located at Andrews Air Force Base, Maryland...

 in 1992), at Wright-Patterson Air Force Base
Wright-Patterson Air Force Base
Wright-Patterson Air Force Base is a United States Air Force base in Greene and Montgomery counties in the state of Ohio. It includes both Wright and Patterson Fields, which were originally Wilbur Wright Field and Fairfield Aviation General Supply Depot. Patterson Field is located approximately...

, Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...

, from 1947 to 1948. On his way to the United States, Jentschke wrote to 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....

 that his reasons for going there was to do real scientific work, which then not possible in Austria and Germany.

In 1950, Jentschke became a resident assistant professor, and in 1955 resident professor, in the Department of Physics at the University of Illinois at Urbana-Champaign
University of Illinois at Urbana-Champaign
The University of Illinois at Urbana–Champaign is a large public research-intensive university in the state of Illinois, United States. It is the flagship campus of the University of Illinois system...

. In 1951, he became director of the Cyclotron Laboratory there.

During 1956 and 1957, Jentschke 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
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...

 (chairman), Hans Kopfermann
Hans Kopfermann
Hans Kopfermann was a German atomic and nuclear physicist. He devoted his entire career to spectroscopic investigations, and he did pioneering work in measuring nuclear spin...

 (vice-chairman), Fritz Bopp, 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....

, 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...

, Otto Haxel
Otto Haxel
Otto Haxel was a German nuclear physicist. During World War II, he worked on the German nuclear energy project. After the war, he was on the staff of the Max Planck Institute for Physics in Göttingen...

, Heinz Maier-Liebnitz, 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:...

, Wolfgang Riezler, Wilhelm Walcher
Wilhelm Walcher
Wilhelm Walcher was a German experimental physicist. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club; he worked on mass spectrometers for isotope separation. After the war, he was director of the Institute of Physics at the University of Marburg...

, 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...

. Wolfgang Paul
Wolfgang Paul
Wolfgang Paul was a German physicist, who co-developed the non-magnetic quadrupole mass filter which laid the foundation for what we now call an ion trap...

 was also a member of the group during 1957.

In 1956, Jentschke became an ordinarius Professor of Physics 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...

. There, he found a positive climate, as well as funding, for his vision of building a new institute around a particle accelerator. An international particle accelerator conference at CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...

 in 1956 was helpful in the decision of which accelerator to build. His vision could not be supported by Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...

 alone, so negotiations took place to bring in support of the Federal Republic of Germany
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...

 and the States of Germany
States of Germany
Germany is made up of sixteen which are partly sovereign constituent states of the Federal Republic of Germany. Land literally translates as "country", and constitutionally speaking, they are constituent countries...

 (Länder). A financial agreement was signed on 18 December 1959, which founded the Deutsches Elektronen-Synchrotron
DESY
The DESY is the biggest German research center for particle physics, with sites in Hamburg and Zeuthen....

(DESY), a 7.5 GeV
Electronvolt
In physics, the electron volt is a unit of energy equal to approximately joule . By definition, it is equal to the amount of kinetic energy gained by a single unbound electron when it accelerates through an electric potential difference of one volt...

 electron synchrotron
Synchrotron
A synchrotron is a particular type of cyclic particle accelerator in which the magnetic field and the electric field are carefully synchronised with the travelling particle beam. The proton synchrotron was originally conceived by Sir Marcus Oliphant...

. Jentschke was chairman of the DESY Board of Directors from 1959 to 1970, and for many years also the director of the Second Institute of Experimental Physics at the University of Hamburg. While at DESY, Jentschke endorsed the electron-positron storage ring scheme for the DORIS accelerator, and promoted the use of synchrotron radiation
Synchrotron radiation
The electromagnetic radiation emitted when charged particles are accelerated radially is called synchrotron radiation. It is produced in synchrotrons using bending magnets, undulators and/or wigglers...

 for research purposes.

In 1971, Jentschke accepted the post as Director General of CERN
CERN
The European Organization for Nuclear Research , known as CERN , is an international organization whose purpose is to operate the world's largest particle physics laboratory, which is situated in the northwest suburbs of Geneva on the Franco–Swiss border...

 Laboratory I (the Meyrin site); John Adams
John Adams (physicist)
Sir John Bertram Adams KBE FRS was a British nuclear physicist and administrator.During World War II, Adams worked in the Radar laboratories of the British Ministry of Aircraft Production where he learned physics and engineering on the job. After the war he moved to Harwell and the Atomic Energy...

 was Director General of the neighboring CERN Laboratory II (Prévessin), where the new SPS proton synchrotron was being constructed. They shared the directorship of CERN until the two laboratories were united in 1976. While Director General, Jentschke oversaw the exploitation of the new research tool, the Intersecting Storage Rings
Intersecting Storage Rings
The ISR was a particle accelerator at CERN. It was the world's first hadron collider, and ran from 1971 to 1984, with a maximum center of mass energy of 62 GeV...

, which began operation in 1971.

Jentschke retired from the University of Hamburg in 1980.

Honors

  • Professor Jentschke was the recipient of a number of honors:

  • Member, Akademie der Wissenschaften und Literatur (In German), Mainz

  • Corresponding Member, Österreichische Akademie der Wissenschaften
    Austrian Academy of Sciences
    The Austrian Academy of Sciences is a legal entity under the special protection of the Federal Republic of Austria. According to the statutes of the Academy its mission is to promote the sciences and humanities in every respect and in every field, particularly in fundamental research...

    , Vienna

  • Honorary Doctor's Degree, University of Illinois

  • Honorary Doctor's Degree, RWTH Aachen
    RWTH Aachen
    RWTH Aachen University is a research university located in Aachen, North Rhine-Westphalia, Germany with roughly 33,000 students enrolled in 101 study programs....

    , 1990

  • John T.Tate Award of the American Institute of Physics
    American Institute of Physics
    The American Institute of Physics promotes science, the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies...

    , 1996

Internal Reports

The following reports were published in Kernphysikalische Forschungsberichte
Kernphysikalische Forschungsberichte
Kernphysikalische Forschungsberichte was an internal publication of the German Uranverein, which was initiated under the Heereswaffenamt in 1939; in 1942, supervision of the Uranverein was turned over to the Reichsforschungsrat under the Reichserziehungsministerium...

(Research Reports in Nuclear Physics), an internal publication of the German Uranverein
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...

. 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
Operation Alsos
Operation Alsos was an effort at the end of World War II by the Allies , branched off from the Manhattan Project, to investigate the German nuclear energy project, seize German nuclear resources, materials and personnel to further American research and to prevent their capture by the Soviets, and...

 and sent to the United States Atomic Energy Commission
United States Atomic Energy Commission
The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S...

 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
American Institute of Physics
The American Institute of Physics promotes science, the profession of physics, publishes physics journals, and produces publications for scientific and engineering societies. The AIP is made up of various member societies...

.
  • Willibald Jentschke and F. Prankl Energien und Massen der Urankernbruchstücke (August 1940) G-44.

  • Willibald Jentschke Energien und Massen der Urankernbrüchstücke bei Bestrahlung mit schnellen (Rn + Be)-Neutronen (16 September 1941) G-99.

Selected Literature

  • Willibald Jentschke, F. Prankl, and F. Hernegger Die Spaltung des Ioniums under Neutronenebestrahlung, Die Naturwissenschaften
    Die Naturwissenschaften
    Naturwissenschaften is a monthly peer-reviewed scientific journal published by Springer on behalf of several learned societies.- History :...

    Volume 28, Issue 20, 315-316 (1940)

  • Willibald Jentschke and Friedlich Prankl Energien und Massen der Urankernbruchstücke bei Bestrahlung mit vorwiegend thermischen Neutronen, Zeitschrift für Physik Volume 119, Numbers 11-12, 696-712 (1942). Received 27 June 1942. Jentschke was identified as being at the II. Physikalisches Institut der Universität Wien, Wien and Prankl was identified as being at the Institut für Radiumforschung, Österreich.

  • Willibald Jentschke Energien und Massen der Urankernbruchstücke bei Bestrahlung mit Neutronen, Zeitschrift für Physik Volume 120, Numbers 3-4, 165-184 (1943). Received 18 September 1942. Jentschke was identified as being a the II. Physikalisches Institut d. Universität, Wien.
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