Nier, Alfred O. C.

Nier, Alfred O. C. (Otto Carl)

(1911–  ) physicist; born in St. Paul, Minn. He was a fellow at Harvard (1936–38), taught at the University of Minnesota (1938–43), and became a physicist at Kellex Corporation, N.Y., before returning to Minnesota as a professor (1945–80). He developed the high-resolution mass spectrometer to study rare isotopes, and (1940) separated and determined the fissionability of uranium-235.