Peter Herbert Jensen
Encyclopedia
Peter Herbert Jensen was a German
experimental nuclear physicist
. During World War II
, he worked on the German nuclear energy project, known as the Uranverein. After the war, he was a department director in the high-voltage section of the Max Planck Institute for Chemistry, in Mainz, and a supernumerary professor University of Mainz.
. He received his doctorate in 1938, under Georg Joos
at the University of Göttingen.
Institut für Physik at the Kaiser-Wilhelm Institut für medizinische Forschung (KWImF, Kaiser Wilhelm Institute for Medical Research, reorganized and renamed in 1948 the Max-Planck Institut für medizinische Forschung
), in Heidelberg
. He was a teaching assistant there to Walther Bothe
from 1939 to 1946. During this time, Jensen worked on the German nuclear energy project
, also known as the Uranverein (Uranium Club); his work with Walther Bothe
, Arnold Flammersfeld
, and Wolfgang Gentner
appeared as Internal Reports in the Kernphysikalische Forschungsberichte
(Research Reports in Nuclear Physics) . Jensen completed his Habilitation
at the Ruprecht-Karls-Universität Heidelberg in 1943. The subject of his Habilitationsschrift was on nuclear cross sections of neutron scattering experiments conducted at the University of Heidelberg.
In the latter years of World War II, Berlin scientific organizations moved equipment and personnel out of the city to escape effects of Allied air raids. The Kaiser-Wilhelm Institut für Physik (KWIP, Kaiser Wilhelm Institute for Physics) had partly evacuated to Hechingen
and Haigerloch
in southern Germany. The Uranmaschine (nuclear reactor) B 8 (B-VIII) was constructed in Haigerloch. The construction of the reactor utilized 1.5 tons of heavy water
, 1.5 tons of uranium, and 10 tons of graphite. The configuration was uranium in the form of cubes (40 chains of 9 cubes each and 38 chains of 8 cubes each) in heavy water surrounded by graphite. The report on the B 8 experiment was written by Fritz Bopp, Erich Fischer
, Werner Heisenberg
, and Karl Wirtz
from the KWIP and Walther Bothe
, Peter Jensen, and Oskar Ritter
from the KWImF.
From 1946 to 1953, Jensen was Wolfgang Gentner’s teaching assistant at the University of Freiburg; from 1953 to 1954 he was a senior assistant there. From 1947 he was a lecturer, and from 1951 he was a supernumerary professor (nichtplanmäßiger Professor) focusing on the installation of a Van de Graaff generator
for experiments in nuclear physics.
From 1954, he was a department director in the high-voltage section of the Max-Planck Institut für Chemie - Otto Hahn Institut
, in Mainz
, and he was a supernumerary professor at the Johannes Gutenberg-Universität Mainz.
(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
.
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
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 worked on the German nuclear energy project, known as the Uranverein. After the war, he was a department director in the high-voltage section of the Max Planck Institute for Chemistry, in Mainz, and a supernumerary professor University of Mainz.
Education
From 1932 to 1938, Jensen studied at the Universität Göttingen and the Albert-Ludwigs-Universität FreiburgUniversity of Freiburg
The University of Freiburg , sometimes referred to in English as the Albert Ludwig University of Freiburg, is a public research university located in Freiburg im Breisgau, Baden-Württemberg, Germany.The university was founded in 1457 by the Habsburg dynasty as the...
. He received his doctorate in 1938, under 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...
at the University of Göttingen.
Career
In 1938, Jensen was a volunteer in Walther Bothe'sWalther Bothe
Walther Wilhelm Georg Bothe was a German nuclear physicist, who shared the Nobel Prize in Physics in 1954 with Max Born....
Institut für Physik at the Kaiser-Wilhelm Institut für medizinische Forschung (KWImF, Kaiser Wilhelm Institute for Medical Research, reorganized and renamed in 1948 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...
. He was a teaching assistant there 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....
from 1939 to 1946. During this time, Jensen worked on 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); his work with 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....
, Arnold Flammersfeld
Arnold Flammersfeld
Arnold Rudolf Karl Flammersfeld was a German nuclear physicist who worked on the German nuclear energy project during World War II...
, and 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...
appeared as Internal Reports in the 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) . Jensen 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...
at the Ruprecht-Karls-Universität Heidelberg in 1943. The subject of his Habilitationsschrift was on nuclear cross sections of neutron scattering experiments conducted at the University of Heidelberg.
In the latter years of World War II, Berlin scientific organizations moved equipment and personnel out of the city to escape effects of Allied air raids. The Kaiser-Wilhelm Institut für Physik (KWIP, Kaiser Wilhelm Institute for Physics) had partly evacuated to Hechingen
Hechingen
Hechingen is a town in central Baden-Württemberg, Germany. It is situated about south of the state capital of Stuttgart and north of Lake Constance and the Swiss border.- City districts :...
and Haigerloch
Haigerloch
-Geography:-Geographical situation:Haigerloch lies at between 430 and 550 metres elevation in the valley of the Eyach, which forms two loops in a steep shelly limestone valley...
in southern Germany. The Uranmaschine (nuclear reactor) B 8 (B-VIII) was constructed in Haigerloch. The construction of the reactor utilized 1.5 tons of heavy water
Heavy water
Heavy water is water highly enriched in the hydrogen isotope deuterium; e.g., heavy water used in CANDU reactors is 99.75% enriched by hydrogen atom-fraction...
, 1.5 tons of uranium, and 10 tons of graphite. The configuration was uranium in the form of cubes (40 chains of 9 cubes each and 38 chains of 8 cubes each) in heavy water surrounded by graphite. The report on the B 8 experiment was written by Fritz Bopp, Erich Fischer
Erich Fischer
Erich Horst Fischer was a German experimental physicist. He worked at the Kaiser Wilhelm Institute for Physics and contributed to the German nuclear energy project, also known as the Uranium Club...
, 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 Karl Wirtz
Karl Wirtz
Karl Eugen Julius Wirtz was a German nuclear physicist. 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:...
from the KWIP and 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....
, Peter Jensen, and Oskar Ritter
Oskar Ritter
Oskar Ritter was a German physicist. During World War II, he worked on the German nuclear energy project, also known as the Uranium Club.-Education:Ritter studied at the Julius-Maximilians-Universität Würzburg and the Universität Leipzig...
from the KWImF.
From 1946 to 1953, Jensen was Wolfgang Gentner’s teaching assistant at the University of Freiburg; from 1953 to 1954 he was a senior assistant there. From 1947 he was a lecturer, and from 1951 he was a supernumerary professor (nichtplanmäßiger Professor) focusing on the installation of a Van de Graaff generator
Van de Graaff generator
A Van de Graaff generator is an electrostatic generator which uses a moving belt to accumulate very high voltages on a hollow metal globe on the top of the stand. It was invented in 1929 by American physicist Robert J. Van de Graaff. The potential differences achieved in modern Van de Graaff...
for experiments in nuclear physics.
From 1954, he was a department director in the high-voltage section of the Max-Planck Institut für Chemie - Otto Hahn Institut
Max Planck Institute for Chemistry
The Max Planck Institute for Chemistry is a scientific research institute under the Max-Planck-Gesellschaft.Basic research in chemistry and related subjects is carried out at the four departments of the institute. The departments are independently led by their Directors.-The departments:The...
, in Mainz
Mainz
Mainz under the Holy Roman Empire, and previously was a Roman fort city which commanded the west bank of the Rhine and formed part of the northernmost frontier of the Roman Empire...
, and he was a supernumerary professor at the Johannes Gutenberg-Universität Mainz.
Internal Reports
The following reports were published in Kernphysikalische ForschungsberichteKernphysikalische 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...
.
- Arnold FlammersfeldArnold FlammersfeldArnold Rudolf Karl Flammersfeld was a German nuclear physicist who worked on the German nuclear energy project during World War II...
, Peter Jensen, Wolfgang GentnerWolfgang GentnerWolfgang 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...
Die Energietönung der Uranspaltung G-25 (21 May 1940)
- Arnold Flammersfeld, Peter Jensen, Wolfgang Gentner Die Aufteilungsverhältnisse und Energietönung bei der Uranspaltung G-26 (24 September 1940)
- Walther Bothe and Peter Jensen Die Absorption thermischer Neutronen in Elektrogrphit G-71 (20 January 1941)
- Walther Bothe and Peter Jensen Resonanzeinfang an einer Uranoberfläche G-72 (12 May 1941)
- Peter Jensen Eine weitere Bestimmung des Absorptionsquerschnittes von 38 für thermische Neutronen G-98 (28 July 1941)
Selected literature
- W. Bothe and P. Jensen Die Absorption thermischer Neutronen in Kohlenstoff, Zeitschrift für Physik Volume 122, Issues 9-12, 749-755 (1944). Received on 21 January 1944. Institutional affiliation: Institut für Physik am Kaiser Wilhelm-Institut für medizinische Forschung, Heidelberg. (As cited in Hentschel and Hentschel, 1996, 370n43, this paper has a footnote stating that the paper was written in July 1940.)
- Peter Jensen Die Bremsung von Neutronen in Kohlenstoff, Wasser und schwerem Wasser, Zeitschrift für Physik Volume 122, Issues 9-12, 756-768 (1944). Received on 21 January 1944. Institutional affiliation: Institut für Physik am Kaiser Wilhelm-Institut für medizinische Forschung, Heidelberg. (As cited in Hentschel and Hentschel, 1996, 366n24, this paper has a footnote stating that the paper was written in July 1940.)
- Helmut Steinwedel, J. Hans D. JensenJ. Hans D. JensenJohannes Hans Daniel Jensen was a German nuclear physicist. During World War II, he worked on the German nuclear energy project, known as the Uranium Club, in which he made contributions to the separation of uranium isotopes. After the war Jensen was a professor at the University of Heidelberg...
, and Peter Jensen Nuclear Dipole Vibrations, Phys. Rev. Volume 79, Issue 6, 1019 - 1019 (1950). Institutional affiliations: Steinwedel and J. H. D. Jensen - Institut für theoretische Physik, Universität Heidelberg and Peter Jensen - Physikalisches Institut, Universität Freiburg. Received 10 July 1950.