Charles Christian Lauritsen
Encyclopedia
Charles Christian Lauritsen (April 4, 1892–April 13, 1968) was a Danish
-born, American
physicist
.
with his wife Sigrid Henriksen and son Tommy, first to Florida, where the family lived for a time on a houseboat, and later to Boston, where he worked as a draftsman during the Great War
and was a witness to the Boston Molasses Disaster
. By 1921 he was working in Palo Alto on radio for communicating between ship and shore. He became interested in the design of radio receivers, and for a few months in 1922 was in business with two partners building radios. By 1923 he had moved to St. Louis
where he was chief engineer at the Kennedy Corporation, a producer of consumer radio receivers.
In 1926 Lauritsen attended a public lecture by Robert Millikan who, in casual conversation afterwards, invited him to visit Caltech
. Lauritsen and his family soon moved to Pasadena
where he talked his way into graduate study in physics. In 1929 he received his Ph.D.
, and in 1930 he joined the physics department faculty. He spent the remainder of his academic career as Professor of Physics at this institution, finally retiring in 1962.
In 1928 he and Ralph D. Bennett developed X-ray
tubes of exceptionally high voltage. These tubes were then used for radiation therapy of cancer
patients in the Kellogg Radiation Laboratory, built as a treatment clinic in 1931. Sigrid Lauritsen, who was one of the first female graduates of the University of Southern California
medical school, worked in the clinic as a radiologist. In 1932 Lauritsen converted one of his X-ray tubes into an accelerator of protons and helium ions and began to study nuclear reactions. In 1934, Lauritsen and H. Richard Crane used a sample of recently discovered deuterium
, obtained from G.N. Lewis at Berkeley, to generate neutron
s with which they made the first accelerator produced articial radioactivity. He later measured the radiation produced when a positron
and an electron
annihilate each other. One of his most significant discoveries was to show that protons could be captured by a carbon
nucleus
, releasing gamma ray
s. This radiative capture process was applied to the study of the nuclear processes at the heart of a star
, and the production of the heavier elements. In 1939 the laboratory ceased to do medical therapy and concentrated on nuclear physics. (Lauritsen was director of the laboratory from its inception until he retired in 1962.)
In 1937 he invented a radiation detector called the Lauritsen electroscope, widely used as quartz fiber radiation dosimeters.
, Lauritsen began work on weapons and weapons design. His initial work was on the design and development of the proximity fuze, but for most of the war he ran a large program at Caltech that developed and manufactured a variety of rocket weapons, mostly for the Navy. In this connection he helped found the Naval Ordinance Test Station (now the The Naval Air Warfare Center, Weapons Division, China Lake) at Inyokern, California
. In the last months of the war, he helped in the American efforts to design and build an atomic bomb, including development of the "pumpkin bomb
", a high explosive copy of the Fat Man
bomb.
He continued his weapons work in the years following the war, and much of his work was classified. Among the projects in which he participated were Project Hartwell, Project Charles, Project Michael, and Project Vista. During the Korean War
he was at the front lines just after the Inchon landings observing and evaluating American weaponry for the Defense Department. He served as an adviser to the U.S. government and as a member of many committees and other groups.
After a lengthy struggle with cancer, he died on April 13, 1968.
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
-born, American
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
.
Early life and career
Lauritsen was born in Holstebro, Denmark and studied architecture at the Odense Tekniske Skole, graduating in 1911. In 1916 he emigrated to the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
with his wife Sigrid Henriksen and son Tommy, first to Florida, where the family lived for a time on a houseboat, and later to Boston, where he worked as a draftsman during the Great War
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...
and was a witness to the Boston Molasses Disaster
Boston molasses disaster
The Boston Molasses Disaster, also known as the Great Molasses Flood and the Great Boston Molasses Tragedy, occurred on January 15, 1919, in the North End neighborhood of Boston, Massachusetts in the United States. A large molasses storage tank burst, and a wave of molasses rushed through the...
. By 1921 he was working in Palo Alto on radio for communicating between ship and shore. He became interested in the design of radio receivers, and for a few months in 1922 was in business with two partners building radios. By 1923 he had moved to St. Louis
St. Louis, Missouri
St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...
where he was chief engineer at the Kennedy Corporation, a producer of consumer radio receivers.
In 1926 Lauritsen attended a public lecture by Robert Millikan who, in casual conversation afterwards, invited him to visit Caltech
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
. Lauritsen and his family soon moved to Pasadena
Pasadena, California
Pasadena is a city in Los Angeles County, California, United States. Although famous for hosting the annual Rose Bowl football game and Tournament of Roses Parade, Pasadena is the home to many scientific and cultural institutions, including the California Institute of Technology , the Jet...
where he talked his way into graduate study in physics. In 1929 he received his Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
, and in 1930 he joined the physics department faculty. He spent the remainder of his academic career as Professor of Physics at this institution, finally retiring in 1962.
In 1928 he and Ralph D. Bennett developed X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
tubes of exceptionally high voltage. These tubes were then used for radiation therapy of cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
patients in the Kellogg Radiation Laboratory, built as a treatment clinic in 1931. Sigrid Lauritsen, who was one of the first female graduates of the University of Southern California
University of Southern California
The University of Southern California is a private, not-for-profit, nonsectarian, research university located in Los Angeles, California, United States. USC was founded in 1880, making it California's oldest private research university...
medical school, worked in the clinic as a radiologist. In 1932 Lauritsen converted one of his X-ray tubes into an accelerator of protons and helium ions and began to study nuclear reactions. In 1934, Lauritsen and H. Richard Crane used a sample of recently discovered deuterium
Deuterium
Deuterium, also called heavy hydrogen, is one of two stable isotopes of hydrogen. It has a natural abundance in Earth's oceans of about one atom in of hydrogen . Deuterium accounts for approximately 0.0156% of all naturally occurring hydrogen in Earth's oceans, while the most common isotope ...
, obtained from G.N. Lewis at Berkeley, to generate neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
s with which they made the first accelerator produced articial radioactivity. He later measured the radiation produced when a positron
Positron
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has an electric charge of +1e, a spin of ½, and has the same mass as an electron...
and an electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
annihilate each other. One of his most significant discoveries was to show that protons could be captured by a carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
nucleus
Atomic nucleus
The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discovered in 1911, as a result of Ernest Rutherford's interpretation of the famous 1909 Rutherford experiment performed by Hans Geiger and Ernest Marsden, under the direction of Rutherford. The...
, releasing gamma ray
Gamma ray
Gamma radiation, also known as gamma rays or hyphenated as gamma-rays and denoted as γ, is electromagnetic radiation of high frequency . Gamma rays are usually naturally produced on Earth by decay of high energy states in atomic nuclei...
s. This radiative capture process was applied to the study of the nuclear processes at the heart of a star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
, and the production of the heavier elements. In 1939 the laboratory ceased to do medical therapy and concentrated on nuclear physics. (Lauritsen was director of the laboratory from its inception until he retired in 1962.)
In 1937 he invented a radiation detector called the Lauritsen electroscope, widely used as quartz fiber radiation dosimeters.
Weapons development
In 1940, more than a year before the U.S. entered World War IIWorld 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...
, Lauritsen began work on weapons and weapons design. His initial work was on the design and development of the proximity fuze, but for most of the war he ran a large program at Caltech that developed and manufactured a variety of rocket weapons, mostly for the Navy. In this connection he helped found the Naval Ordinance Test Station (now the The Naval Air Warfare Center, Weapons Division, China Lake) at Inyokern, California
Inyokern, California
Inyokern is a census-designated place in Kern County, California, United States. Inyokern is located west of Ridgecrest, at an elevation of 2434 feet . Located in the Indian Wells Valley. The population was 1,099 at the 2010 census, up from 984 at the 2000 census...
. In the last months of the war, he helped in the American efforts to design and build an atomic bomb, including development of the "pumpkin bomb
Pumpkin bomb
Pumpkin bombs were conventional high explosive aerial bombs developed by the Manhattan Project and used by the United States Army Air Forces against Japan during World War II...
", a high explosive copy of the Fat Man
Fat Man
"Fat Man" is the codename for the atomic bomb that was detonated over Nagasaki, Japan, by the United States on August 9, 1945. It was the second of the only two nuclear weapons to be used in warfare to date , and its detonation caused the third man-made nuclear explosion. The name also refers more...
bomb.
He continued his weapons work in the years following the war, and much of his work was classified. Among the projects in which he participated were Project Hartwell, Project Charles, Project Michael, and Project Vista. During the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...
he was at the front lines just after the Inchon landings observing and evaluating American weaponry for the Defense Department. He served as an adviser to the U.S. government and as a member of many committees and other groups.
After a lengthy struggle with cancer, he died on April 13, 1968.
Awards and honors
- Elected to the Royal Danish Academy of Sciences and Letters, 1939.
- Appointed Commander of the Order of Dannebrog, 1953, by the King of DenmarkFrederick IX of DenmarkFrederick IX was King of Denmark from 20 April 1947 until his death on 14 January 1972....
. - President of the American Physical SocietyAmerican Physical SocietyThe American Physical Society is the world's second largest organization of physicists, behind the Deutsche Physikalische Gesellschaft. The Society publishes more than a dozen scientific journals, including the world renowned Physical Review and Physical Review Letters, and organizes more than 20...
, 1951. - Awarded the Tom W. Bonner Prize, 1967.
- Awarded an honorary Doctor of Laws degree by UCLA, 1965.
- The crater LauritsenLauritsen (crater)Lauritsen is a lunar crater that is located just behind the east-southeastern limb of the Moon. While it lies on the far side from the Earth, it is still possible to catch a glimse of this area under favorable conditions of libration and illumination...
on the MoonMoonThe Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
is named after him.
External links
- Guide to the Papers of Charles Christian Lauritsen, 1927-1977 including his biography.
- Target Committee, Los Alamos, May 10-11, 1945