CAMERON, ANGUS EWAN

(b. Sylvania, Pennsylvania, 14 October 1906; d. Oak Ridge, Tennessee, 28 September 1981)

physical chemistry, mass spectroscopy.

Cameron was known and highly respected by his colleagues as a physical chemist and mass spectroscopist. His ideas and perceptions, which he did not hold back, strongly influenced associates in the research laboratory and in scientific meetings. He possessed a critical judgment that few ever attain. His specialty and expertise focused on the measurement of isotopic abundance of the elements. He was particularly interested in the determination of lithium and its isotopic variability in the earth’s crust, as well as in the age and origin of the universe. He was a member of Alpha Chi Sigma, Sigma Xi, the American Chemical Society, and the American Society for Mass Spectrometry.

The son of Alexander George Cameron and Jennie Hoover, Cameron received his undergraduate education at Oberlin College, graduating magna cum laude in 1928. He received his doctorate in physical chemistry from the University of Minnesota in 1932. In 1933 he was awarded a one-year National Research Council postdoctoral fellowship to the School of Optics at the University of Rochester (New York). In the same year he married Jane Williams Gray. They had three sons: Allan. Douglas, and Alexander.

Cameron’s first position (1934) was with the Eastman Kodak Company in Rochester, New York. Except for brief employment with other laboratories, he spent the best part of ten years with Eastman Kodak, doing physical chemical research concerned mainly with photographic processing. Cameron transferred to the Manhattan Project at Oak Ridge, Tennessee, in 1943. It was there that the fissionable uranium isotope (U²³⁵) was first separated from normal uranium by an electromagnetic process. The first atomic bombs were made from the product of these separations, Cameron, with Alfred Nier, Roger Hibbs, William Harman. and others, set up the first mass spectroscopy laboratory to measure separated isotopes of uranium. His knowledge of optics and his talents in mass spectroscopy were vital to the success of the electromagnetic separation process and, ultimately, to the whole Manhattan Project.

In 1947 Cameron returned to the Eastman Kodak laboratory, where he did research on high-vacuum distillation techniques. A year later he went back to the Oak Ridge area and settled down to research and administration at the Oak Ridge Gaseous Diffusion Plant (K-25) for the Carbide and Carbon Chemicals Company, the operating contractor, At this site large process buildings were being built to house the new gaseous-diffusion separation units. Thenew method of separation, using UF₆, was much cheaper and easier to scale up than the electromagnetic separation method it was replacing. Cameron’s leadership and knowledge furthered vacuum distillation, mass spectroscopy, and isotope separation technology for six years. With D. F. Eggers, Jr., he made an important contribution to mass spectrometry in 1948 when they developed what Cameron called an “ion velocitron,” a form of the present-day time-of-flight instrument, which displayed the entire mass spectrum at one time.

In 1954 Cameron took a year’s leave of absence to accept a Fulbright fellowship to the Max Planck Institute of Chemistry at Mainz, Germany, There he met and collaborated with such research leaders in mass spectroscopy as Josef Mattauch and Heinrich Hintenberger. During this association he became further engrossed in the measurement of atomic weights of the elements and the age of the universe.

His zeal for the measurement of atomic weights led to Cameron’s participation in and involvement with the Commission on Atomic Weights of the International Union of Pure and Applied Chemistry (IUPAC), on which he served for more than twenty years. He continually prodded his colleagues to report their results when they made isotopic composition measurements on elements that are variable in nature or have large uncertainties, because they could be quite valuable to the scientific community and to the IUPAC as it sought to determine best values.

Cameron returned to Oak Ridge (K-25) in 1955 and a short time later transferred to the Oak Ridge National Laboratory (ORNL), where he served as an assistant director of the Analytical Chemistry Division and headed the mass spectrometry department from 1957 until his retirement in 1971.

After his retirement from ORNL, Cameron did consulting work for ORNL, Oak Ridge Associated Universities, and Litton Systems. While with the latter he was involved with the design and construction of the analytical instrument package for the Mars Viking lander that identified and measured the composition of the atmosphere of Mars in 1975.

Cameron received the Distinguished Alumni Award from the University of Minnesota in 1955, and a certificate of appreciation from the U.S. Department of Energy for his many contributions to the classified work done at the Oak Ridge plants.

BIBLIOGRAPHY

I. Original Works. Cameron wrote more than one hundred technical papers and reports and was awarded three patents for improved components for mass spectrometers. The following articles reflect his research and interests in measurements of atomic weights and isotopic abundances: “An ion Velocitron,” in Review of Scientific Instruments, 19 (1948), 605–607. written with D. F. Eggers. Jr.; “Variation in the Natural Abundance of the Lithium Isotopes,” in Journal of the American Chemical Society. 77 (1955), 2731–2733: “Isotopic Composition of Bromine in Nature,” in Science, 121 (1955), 136–137, written with E. L. Lippert, Jr., “Report of the International Commission on Atomic Weights (1961),” in Journal of the American Chemical Society, 84 (1962), 4175–4197, written with Edward Wichers: and “Mass Spectrometry of Nanogram-Size Samples of Lead,” in Analytical Chemistry, 41 (1969), 425–426, written with D. H. Smith and R. L. Walker.

II. Secondary Literature. See Richard Smyser, “Angus Ewan Cameron,” in The Oak Ridger. 30 September 1981; and Raymond L. Walker, J. A. Carter, and W. H. Christie, “in Memorian of A. L. Cameron.” in International Journal of Mass Spectroscopy and Ion Physics, 42 (1982), 1–2. See also Determination of the Isotopic Composition of Uranium. U.S. Atomic Energy Report. TID-5213 (1950): and Clement J. Rodden. ed., Analysis of Essential Nuclear Reactor Materials (Washington. D.C., 1964), ch. 13

Raymond L. Walker