Carl Bjorn Braestrup (April 13, 1897 – August 8, 1982) was an American physicist, engineer and inventor who specialised in

radiation safety Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Expos ...

at the New York Department of Hospitals and

Columbia University Columbia University (also known as Columbia, and officially as Columbia University in the City of New York) is a private research university in New York City. Established in 1754 as King's College on the grounds of Trinity Church in Manhatt ...

Early life

Carl Bjorn Braestrup was born in Copenhagen, Denmark, on April 13, 1897, the son of a Danish naval officer. In 1919 Braestrup emigrated to the United States. He studied at

Carnegie Institute of Technology Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania. One of its predecessors was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools; it became the Carnegie Institute of Technology ...

Pittsburgh Pittsburgh ( ) is a city in the Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County. It is the most populous city in both Allegheny County and Western Pennsylvania, the second-most populous city in Pennsylva ...

and

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a private land-grant research university in Cambridge, Massachusetts. Established in 1861, MIT has played a key role in the development of modern technology and science, and is one of the ...

(MIT), graduating with a

bachelor of science A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University o ...

from MIT in 1922.

Career

After graduation Braestrup worked as an engineer for

Bell Telephone Laboratories Nokia Bell Labs, originally named Bell Telephone Laboratories (1925–1984), then AT&T Bell Laboratories (1984–1996) and Bell Labs Innovations (1996–2007), is an American industrial research and scientific development company owned by mult ...

and Picker X-Ray Company. In 1928 he began working part-time for Columbia University in New York City. From 1929 until 1966 he was director of the physics laboratory of the New York Department of Hospitals. In the early 1930s Braestrup developed one of the first

film badge dosimeter A film badge dosimeter or film badge is a personal dosimeter used for monitoring cumulative radiation dose due to ionizing radiation. The badge consists of two parts: photographic film and a holder. The film emulsion is black and white photographi ...

to detect radiation exposure, a design later adopted by the

Manhattan Project The Manhattan Project was a research and development undertaking during World War II that produced the first nuclear weapons. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project w ...

, the secret project to develop the atomic bomb. Braestrup was part of the team at Columbia University taking part in the Manhattan Project. His work focussed on assessing and minimising the radiation hazard to personnel. His involvement in the atomic weapons program continued after the war, working as a consultant during the nuclear testings at Bikini Atoll. From 1952 to 1963 he worked at

Oak Ridge National Laboratory Oak Ridge National Laboratory (ORNL) is a U.S. multiprogram science and technology national laboratory sponsored by the U.S. Department of Energy (DOE) and administered, managed, and operated by UT–Battelle as a federally funded research an ...

Tennessee Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...

radiation shielding Radiation protection, also known as radiological protection, is defined by the International Atomic Energy Agency (IAEA) as "The protection of people from harmful effects of exposure to ionizing radiation, and the means for achieving this". Exposur ...

and plant inspections. In 1953 Braestrup and D. T. Green patented the Theratron, a machine for irradiating tumours with a focused beam of cobalt radiation which was designed to minimise the exposure to radiation of the health workers applying the treatment. His 1958 book, ''Radiation Protection'', co-authored with Harold Orville Wyckoff, was the first textbook on radiation safety. With Richard T. Mooney, Braestrup investigated x-ray emissions from televisions. Their safety recommendations were adopted by the federal government.

Personal life and death

In 1928 Braestrup married Elsebet Kampmann. They had two children, their son

Peter Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a sur ...

was a correspondent for ''

The New York Times ''The New York Times'' (''the Times'', ''NYT'', or the Gray Lady) is a daily newspaper based in New York City with a worldwide readership reported in 2020 to comprise a declining 840,000 paid print subscribers, and a growing 6 million paid d ...

'' and ''

The Washington Post ''The Washington Post'' (also known as the ''Post'' and, informally, ''WaPo'') is an American daily newspaper published in Washington, D.C. It is the most widely circulated newspaper within the Washington metropolitan area and has a large nati ...

''. Braestrup died on August 8, 1982, aged 85 in Middletown, Connecticut from complications following a stroke.

Books

* *

References

{{DEFAULTSORT:Braestrup, Carl Bjorn 1897 births 1982 deaths Scientists from Copenhagen 20th-century Danish physicists 20th-century American physicists 20th-century Danish engineers 20th-century American engineers 20th-century Danish inventors 20th-century American inventors Carnegie Mellon University alumni Massachusetts Institute of Technology alumni Danish emigrants to the United States Columbia University faculty Manhattan Project people Oak Ridge National Laboratory people Deaths in Connecticut