Siegbahn, Kai 1918–2007

(Kai M. Siegbahn, Kai Manne Börje Siegbahn, Kai Manne Boerje Siegbahn)

OBITUARY NOTICE—

See index for CA sketch: Born April 20, 1918, in Lund, Sweden; died of heart failure, July 20, 2007, in Angelholm, Sweden. Physicist, educator, and author. Siegbahn shared the Nobel Prize in physics in 1981 for his development of high-resolution electron spectroscopy for chemical analysis (or ESCA). It was his own father who had won the same prize more than fifty years earlier for his work on X-ray spectroscopy, but it was the son's technique that proved to be sensitive enough for widespread use as an industrial application. The ESCA technique uses electrons, rather than X-rays or lasers, to test the chemical composition of materials, but it also enables scientists to determine the purity, contamination, or corrosion level of the materials and to identify new chemical elements undetectable by other means. It can be used to analyze a wide range of materials: solid, liquid, gas; organic or inorganic; pure or alloyed; the only excluded elements are helium and hydrogen. ESCA can be applied to identify chemical elements even at the molecular and atomic levels. Siegbahn also made improvements to the spectrometer and other measuring devices to take full advantage of the benefits offered by the ESCA process. Siegbahn had been working on his projects for nearly thirty years. His research began to yield solid results as early as 1954 in his work with sodium chloride, and the first commercially viable electronic spectrometer was produced in 1969. Siegbahn was a researcher at the Nobel Institute of Physics from 1942 to 1951. He was a member of the faculty at the Swedish Royal Institute of Technology when he recorded his initial discoveries. He moved to the University of Uppsala in 1954, where he was a professor of physics and a department head until 1984. Siegbahn was active in many scientific organizations, among them the International Union of Pure and Applied Physics, which he headed in the early 1980s. He was a recipient of many scientific awards in lifetime in addition to the Nobel Prize. Siegbahn's writings include the books ESCA: Atomic, Molecular, and Solid State Structure Studied by Means of Electron Spectroscopy (1967) and ESCA Applied to Free Molecules (1969).

OBITUARIES AND OTHER SOURCES:

PERIODICALS

Chicago Tribune, August 8, 2007, p. 11.

Los Angeles Times, August 8, 2007, p. B8.

New York Times, August 7, 2007, p. C11.

Times (London, England), August 9, 2007, p. 64.

Washington Post, August 6, 2007, p. B5.