Project Y
The Los Alamos Laboratory, also known as Project Y, was a secret laboratory established by the Manhattan Project and operated by the University of California during World War II. Its mission was to design and build the first atomic bombs. Robert Oppenheimer was its first director, serving from 1943 to December 1945, when he was succeeded by Norris Bradbury. In order to enable scientists to freely discuss their work while preserving security, the laboratory was located on the isolated Pajarito Plateau in Northern New Mexico. The wartime laboratory occupied buildings that had once been part of the Los Alamos Ranch School.
"Los Alamos Laboratory" redirects here. For the present-day laboratory, see Los Alamos National Laboratory.Established
1 January 1943
Classified
$57.88 million
Los Alamos, New Mexico, United States
35°52′50″N 106°18′14″W / 35.88056°N 106.30389°W
Central Ave., Los Alamos, New Mexico
1943
Bungalow/Craftsman, Modern Movement
15 October 1966
The development effort initially focused on a gun-type fission weapon using plutonium called Thin Man. In April 1944, the Los Alamos Laboratory determined that the rate of spontaneous fission in plutonium bred in a nuclear reactor was too great due to the presence of plutonium-240 and would cause a predetonation, a nuclear chain reaction before the core was fully assembled. Oppenheimer then reorganized the laboratory and orchestrated an all-out and ultimately successful effort on an alternative design proposed by John von Neumann, an implosion-type nuclear weapon, which was called Fat Man. A variant of the gun-type design known as Little Boy was developed using uranium-235.
Chemists at the Los Alamos Laboratory developed methods of purifying uranium and plutonium, the latter a metal that only existed in microscopic quantities when Project Y began. Its metallurgists found that plutonium had unexpected properties, but were nonetheless able to cast it into metal spheres. The laboratory built the Water Boiler, an aqueous homogeneous reactor that was the third reactor in the world to become operational. It also researched the Super, a hydrogen bomb that would use a fission bomb to ignite a nuclear fusion reaction in deuterium and tritium.
The Fat Man design was tested in the Trinity nuclear test in July 1945. Project Y personnel formed pit crews and assembly teams for the atomic bombings of Hiroshima and Nagasaki and participated in the bombing as weaponeers and observers. After the war ended, the laboratory supported the Operation Crossroads nuclear tests at Bikini Atoll. A new Z Division was created to control testing, stockpiling and bomb assembly activities, which were concentrated at Sandia Base. The Los Alamos Laboratory became Los Alamos Scientific Laboratory in 1947.
Origins[edit]
Nuclear fission and atomic bombs[edit]
The discovery of the neutron by James Chadwick in 1932,[2] followed by the discovery of nuclear fission by chemists Otto Hahn and Fritz Strassmann in 1938,[3][4] and its explanation (and naming) by physicists Lise Meitner and Otto Frisch soon after,[5][6] opened up the possibility of a controlled nuclear chain reaction using uranium. At the time, few scientists in the United States thought that an atomic bomb was practical,[7] but the possibility that a German atomic bomb project would develop atomic weapons concerned refugee scientists from Nazi Germany and other fascist countries, leading to the drafting of the Einstein–Szilard letter to warn President Franklin D. Roosevelt. This prompted preliminary research in the United States, beginning in late 1939.[8]
Organization[edit]
Military[edit]
Colonel John M. Harman was the first post commander at Los Alamos. He joined the Santa Fe office as a lieutenant colonel on 19 January 1943, and was promoted to colonel on 15 February.[79] Los Alamos officially became a military establishment on 1 April 1943, and he moved to Los Alamos on 19 April.[79][80] He was succeeded by Lieutenant Colonel C. Whitney Ashbridge, a graduate of the Los Alamos Ranch School,[81] in May 1943. In turn, Ashbridge was succeeded by Lieutenant Colonel Gerald R. Tyler in October 1944,[79][82] Colonel Lyle E. Seaman in November 1945, and Colonel Herb C. Gee in September 1946.[79] The post commander was answerable directly to Groves, and was responsible for the township, government property and the military personnel.[83]