Manne Karl Georg Siegbahn (3.12.1886—26.09.1978) — a Swedish experimental physicist, a member of the Royal Swedish Academy of Sciences (1922). Born in Örebro. He graduated from the University of Lund (1911), where he worked (professor from 1920); in 1924—37 he was professor at the University of Uppsala, and in 1937—64 director of the Nobel Institute for Physics.
His research concerned X-ray spectroscopy, of which he is one of the founders, and nuclear physics. He developed new methods of obtaining high-resolution X-ray spectra and carried out precision determinations of the wavelengths of X-rays. He studied the X-ray spectra of practically all the chemical elements and detected a considerable number of new spectral lines. He was the first to detect and measure the dispersion of X-rays, and in 1916 discovered the M series in their spectrum. He made a diffraction grating for the study of soft X-rays and constructed an X-ray vacuum spectrograph. He refined the Wulff—Bragg equation. In 1924 he was awarded the Nobel Prize for his research and discoveries in X-ray spectroscopy.
He founded a school of physicists. A member of a number of academies of sciences and learned societies, in particular a foreign member of the USSR Academy of Sciences (1958). The D. Hughes Medal (1934), the B. Rumford Medal (1940) and others.