“Lawrence Marvin Langer”的意思、由来-开放百科全书

Langer was born in New York City on December 22, 1913. He received his B.S. in 1934, M.S. in 1935, and his Ph.D. in 1938 in physics all from New York University. The year that he received his Ph.D., Herman Wells persuaded Alan Mitchell to come to Indiana University to start a modern research program in the physics department, and Langer was one of three additional faculty hired for this purpose. He contributed to the construction of the first Indiana cyclotron, and started a research program applying the beta-gamma coincidence method to the study of nuclear energy level decay schemes^[3]

World War II

As the war approached, Langer was recruited to work in the MIT Radiation Laboratory where he was involved in flight-testing of radar prototypes in fighter planes. He was then called by the Navy to San Diego, where he worked on the development and testing of sonar detectors. In 1943, he was invited to Los Alamos, where he worked on developing the gun mechanism used to set off the atomic bombs.^[1]

50 years after the first atomic bomb was dropped on Hiroshima, Langer was interviewed by the Associated Press. He shared his memories of his help in assembling the bomb on Tinian Island in August, 1945.

Tinian was a South Pacific Island. In 1945 it was the home to the world's largest airfield-six runways each 2 miles long and as wide as a 10 lane highway.^[4]

Hooked into the bomb bay of one of the B-29 Superfortress airplanes nicknamed the Enola Gay, was the 9,700 pound Uranium-235 bomb with the name of Little Boy.

Because planes periodically crashed on takeoff from Tinian, the bomb was not yet armed. Navy Captain William S. "Deak" Parsons was supposed to take care of that once the plane was airborne. Langer had trained Parsons to arm the bomb using a special wrench, and the nervous Parsons kept checking the box on the plane that housed the wrench to make sure it was there.The B-29 and its bomb were guarded by the military police, but Langer was not confident about the security. "My experience with the MPs is that they weren't very reliable so I decided to stay with the bomb and forgo dinner, " Langer said.

As twilight faded into darkness, Longer grew tired. "The only place to stretch out was on top of the bomb so I did and fell asleep," he said.

Langer was awaken by the sound of flashbulbs popping as photographers documented the readying the Enola Gay for its most famous flight. At 2:45 am on August 6, 1945, Colonel Paul Tibbets and his crew lifted off. They dropped Little Boy about 5 hours later^[5]

Indiana University

In 1946 Langer returned to the Indiana University faculty and developed one of the world's major laboratories for the study of beta-ray spectra shapes and other works in nuclear spectroscopy. He was among the earliest physicists to use a shaped-magnetic-field spectrometer to study spectrum shapes, and was a leader in source and detector techniques.

In the late 1940s and early 1950s, Langer and his students worked on confirming the Fermi theory of beta decay for "allowed" transitions. In 1949 he and his student H. Clay Price found the first clear example of a "unique forbidden" shape. In 1952, he and his student R. Douglas Moffat set a significant upper limit on the mass of the neutrino from studies of the beta spectrum of tritium near its end-point. He rcontinued neutrino-related studies, including questions of neutrino-antineutrino identity, a search for neutrino degeneracy, and further studies of neutrino mass. He did some of his work as a consultant, working with collaborators at Los Alamos. Langer and his students also worked on the systematic features of nuclear energy levels, and thus to the confirmation of the nuclear shell and rotational models. His work was influenced by that of his colleague in theoretical physics, Emil Konopinski, and vice versa. Their 1953 "Annual Review" article on what was then known about beta decay was widely cited. Langer supervised 27 students through their Ph.D. work.

He became chair on the Indiana University physics department in 1965 and played a major role in more than doubling the size of the department and introducing new research areas through a National Science Foundation Science Development Program. Simultaneously, he established the innovative Indiana University Cyclotron Facility and Nuclear Theory Center as part of the NSF program.Langer stepped down as chair in 1973, returning to full-time teaching and research. He retired from Indiana in June 1979, as unable to continue research because of complications from multiple sclerosis. He died in Bloomington on January 17, 2000. ^[1]

References

1. ^¹²{{cite journal|url=https://doi.org/10.1063/1.1366080|title=Lawrence Marvin Langer|first1=Guy T.|last1=Emery|first2=Joseph H.|last2=Hamilton|first3=Andrew D.|last3=Bacher|date=1 March 2001|publisher=|journal=Physics Today|volume=54|issue=3|pages=96–98|doi=10.1063/1.1366080}}
2. ^https://doi.org/10.1063.1.1366080 {{Citation not found}}
3. ^webappl.dlib.indiana.edu/bfc/view?docid=B17-2001 {{Citation not found}}
4. ^{{cite web|url=https://www.atomicheritage.org/profile/lawrence-langer|title=Lawrence Langer|publisher=}}
5. ^https://nwtimes.com/uncategorized/iu-scientist-remembers-napping-upon-bomb/article

Early life

World War II

Indiana University

References