Alexander Suss Langsdorf Jr. (May 30, 1912 – May 24, 1996) was an American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

on the team that developed the

atomic bomb A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

and several devices related to nuclear physics. He was a vocal opponent of the use and proliferation of

nuclear weapons A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either nuclear fission, fission (fission or atomic bomb) or a combination of fission and nuclear fusion, fusion reactions (thermonuclear weap ...

.Stout, David (May 26, 1996)
Alexander Langsdorf, 83, Plutonium Pioneer.
''

The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...

Life and career

Langsdorf was born in

St. Louis, Missouri St. Louis ( , sometimes referred to as St. Louis City, Saint Louis or STL) is an Independent city (United States), independent city in the U.S. state of Missouri. It lies near the confluence of the Mississippi River, Mississippi and the Miss ...

. He earned an undergraduate degree from Washington University in St. Louis in 1932 and a doctorate in physics from

Massachusetts Institute of Technology The Massachusetts Institute of Technology (MIT) is a Private university, private research university in Cambridge, Massachusetts, United States. Established in 1861, MIT has played a significant role in the development of many areas of moder ...

in 1937. In this time he developed a continuously sensitive cloud chamber. After a research fellowship at the

University of California at Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a public land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkele ...

, he became a physics instructor at Washington University in St. Louis from 1939 to 1942. Prior to

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, Langsdorf co-developed a

cyclotron A cyclotron is a type of particle accelerator invented by Ernest Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. Lawrence, Ernest O. ''Method and apparatus for the acceleration of ions'', filed: Januar ...

for splitting atomic particles at Washington University in St. Louis . It was designed for use in

medical research Medical research (or biomedical research), also known as health research, refers to the process of using scientific methods with the aim to produce knowledge about human diseases, the prevention and treatment of illness, and the promotion of ...

. During World War II, he worked with

Enrico Fermi Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian and naturalized American physicist, renowned for being the creator of the world's first artificial nuclear reactor, the Chicago Pile-1, and a member of the Manhattan Project ...

at the

University of Chicago The University of Chicago (UChicago, Chicago, or UChi) is a Private university, private research university in Chicago, Illinois, United States. Its main campus is in the Hyde Park, Chicago, Hyde Park neighborhood on Chicago's South Side, Chic ...

on the

Manhattan Project The Manhattan Project was a research and development program undertaken during World War II to produce the first nuclear weapons. It was led by the United States in collaboration with the United Kingdom and Canada. From 1942 to 1946, the ...

. Langsdorf was one of the designers of the first two

nuclear reactor A nuclear reactor is a device used to initiate and control a Nuclear fission, fission nuclear chain reaction. They are used for Nuclear power, commercial electricity, nuclear marine propulsion, marine propulsion, Weapons-grade plutonium, weapons ...

s after Fermi completed the first sustained nuclear chain reaction in 1942. Langsdorf was able to produce a tiny usable sample of

plutonium Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four ...

using his device. That sample was then used in the Trinity nuclear test on July 16, 1945. Langsdorf urged President

Harry S Truman Harry S. Truman (May 8, 1884December 26, 1972) was the 33rd president of the United States, serving from 1945 to 1953. As the 34th Vice president of the United States, vice president in 1945, he assumed the presidency upon the death of Frank ...

not to use the bomb against the Japanese, but a plutonium-based bomb was dropped on

Nagasaki , officially , is the capital and the largest Cities of Japan, city of Nagasaki Prefecture on the island of Kyushu in Japan. Founded by the Portuguese, the port of Portuguese_Nagasaki, Nagasaki became the sole Nanban trade, port used for tr ...

soon after. He continued to urge against expansion of nuclear weapons. He helped found ''

Bulletin of the Atomic Scientists The ''Bulletin of the Atomic Scientists'' is a nonprofit organization concerning science and global security issues resulting from accelerating technological advances that have negative consequences for humanity. The ''Bulletin'' publishes conte ...

'', and his wife Martyl Langsdorf designed the 1947 cover of the publication which debuted the Doomsday Clock. Langsdorf also invented the diffusion cloud chamber and the reactor oscillator. Langsdorf died in

Elmhurst, Illinois Elmhurst is a city in DuPage County, Illinois, DuPage and Cook County, Illinois, Cook counties in the U.S. state of Illinois. It is a western suburb of Chicago. The population was 45,786 at the 2020 United States census, 2020 census. History M ...

, from complications from

hip surgery In vertebrate anatomy, the hip, or coxaLatin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) (: ''coxae'') in medical terminology, refers to either an anatomical region or a joint on t ...

.Staff report (May 25, 1996). Alexander Langsdorf Jr.; Physicist Involved with First Atomic Bomb. '' St Louis Post-Dispatch''

References

External links

1965 Audio Interview with Alexander Langsdorf Jr. by Stephane Groueff
Voices of the Manhattan Project
Alexander Langsdorf Jr. Papers
via Washington University in St. Louis {{DEFAULTSORT:Langsdorf, Alexander Jr. 1912 births 1996 deaths Washington University in St. Louis physicists Manhattan Project people Fellows of the American Physical Society Washington University in St. Louis alumni Massachusetts Institute of Technology alumni University of California, Berkeley fellows