Willard Libby

A 1931 chemistry graduate of the University of California, Berkeley, from which he received his doctorate in 1933, he studied radioactive elements and developed sensitive Geiger counters to measure weak natural and artificial radioactivity. During World War II he worked in the Manhattan Project's Substitute Alloy Materials (SAM) Laboratories at Columbia University, developing the gaseous diffusion process for uranium enrichment.


After the war, Libby accepted a professorship at the University of Chicago's Institute for Nuclear Studies, where he developed the technique for dating organic compounds using carbon-14. He also discovered that tritium similarly could be used for dating water, and therefore wine. In 1950, he became a member of the General Advisory Committee (GAC) of the Atomic Energy Commission (AEC). He was appointed a commissioner in 1954, becoming its sole scientist. He sided with Edward Teller on pursuing a crash program to develop the hydrogen bomb, participated in the Atoms for Peace program, and defended the administration's atmospheric nuclear testing.


Libby resigned from the AEC in 1959 to become professor of chemistry at University of California, Los Angeles (UCLA), a position he held until his retirement in 1976. In 1962, he became the director of the University of California statewide Institute of Geophysics and Planetary Physics (IGPP). He started the first Environmental Engineering program at UCLA in 1972, and as a member of the California Air Resources Board, he worked to develop and improve California's air pollution standards.

Manhattan Project[edit]

On December 8, 1941, the day after the Japanese attack on Pearl Harbor brought the United States into World War II, Libby volunteered his services to Nobel Prize laureate Harold Urey. Urey arranged for Libby to be given leave from the University of California, Berkeley and to join him at Columbia University to work on the Manhattan Project, the wartime project to develop atomic bombs,^[1][6] at what became its Substitute Alloy Materials (SAM) Laboratories.^[12] During his time in the New York City area, Libby was a resident of Leonia, New Jersey.^[13]


Over the next three years, Libby worked on the gaseous diffusion process for uranium enrichment.^[4] An atomic bomb required fissile material, and the fissile uranium-235 made up only 0.7 percent of natural uranium. The SAM Laboratories therefore had to find a way of separating kilograms of it from the more abundant uranium-238. Gaseous diffusion worked on the principle that a lighter gas diffuses through a barrier faster than a heavier one at a rate inversely proportional to its molecular weight. But the only known gas containing uranium was the highly corrosive uranium hexafluoride, and a suitable barrier was hard to find.^[14]


Through 1942, Libby and his team studied different barriers and the means to protect them from corrosion from the uranium hexafluoride.^[15] The most promising type was a barrier made of powdered nickel developed by Edward O. Norris of the Jelliff Manufacturing Corporation and Edward Adler from the City College of New York, which became known as the "Norris-Adler" barrier by late 1942.^[16]


In addition to developing a suitable barrier, the SAM Laboratories also had to assist in the design of a gaseous separation plant, which became known as K-25. Libby helped with the engineers from Kellex to produce a workable design for a pilot plant.^[17] Libby conducted a series of tests that indicated that the Norris-Adler barrier would work, and he remained confident that with an all-out effort, the remaining problems with it could be solved. Although doubts remained, construction work began on the K-25 full-scale production plant in September 1943.^[18]


As 1943 gave way to 1944, many problems remained. Tests began on the machinery at K-25 in April 1944 without a barrier. Attention turned to a new process developed by Kellex. Finally, in July 1944, Kellex barriers began to be installed in K-25.^[19] K-25 commenced operation in February 1945, and as cascade after cascade came online, the quality of the product increased. By April 1945, K-25 had attained a 1.1% enrichment.^[20] Uranium partially enriched in K-25 was fed into the calutrons at Y-12 to complete the enrichment process.^[21]


Construction of the upper stages of the K-25 plant was cancelled, and Kellex was directed to instead design and build a 540-stage side feed unit, which became known as K-27.^[22] The last of K-25's 2,892 stages commenced operation in August 1945.^[20] On August 5, K-25 starting producing feed enriched to 23 percent uranium-235.^[23] K-25 and K-27 achieved their full potential only in the early postwar period, when they eclipsed the other production plants and became the prototypes for a new generation of plants.^[20] Enriched uranium was used in the Little Boy bomb employed in the bombing of Hiroshima on August 6, 1945.^[24] Libby brought home a stack of newspapers and told his wife, "This is what I've been doing."^[6]

Awards and honors[edit]

Libby was an elected member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the American Philosophical Society.^[3] In addition to the Nobel Prize, he received numerous honors and awards, including Columbia University's Chandler Medal in 1954,^[37] the Remsen Memorial Lecture Award in 1955, the Bicentennial Lecture Award from the City College of New York and the Nuclear Applications in Chemistry Award in 1956, the Franklin Institute's Elliott Cresson Medal in 1957, the American Chemical Society's Willard Gibbs Award in 1958, the Joseph Priestley Award from Dickinson College and the Albert Einstein Medal in 1959, the Geological Society of America's Arthur L. Day Medal in 1961,^[38] the Golden Plate Award of the American Academy of Achievement in 1961,^[39] the Gold Medal of the American Institute of Chemists in 1970,^[40] and the Lehman Award from the New York Academy of Sciences in 1971. He was elected a member of the National Academy of Sciences in 1950.^[38] Analy High School library has a mural of Libby,^[5] and a Sebastopol city park and a nearby highway are named in his honor.^[41] His 1947 paper on radiocarbon dating was honored by a Citation for Chemical Breakthrough Award from the Division of History of Chemistry of the American Chemical Society presented to the University of Chicago in 2016.^[42][43][29]