Clifford Shull, 1915–2001, American physicist, b. Pittsburgh, Pa. Educated at Carnegie Institute of Technology (now Carnegie Mellon University) and New York Univ. (Ph.D., 1941), Shull was on the staff of the Texas Company (1941–46) and the Clinton Laboratories (1946–55; Oak Ridge National Laboratory after 1948) before joining the faculty at the Massachusetts Institute of Technology (1955–86). While at Oak Ridge he showed that a beam of neutrons directed at a sample of a given material is scattered by the atoms in the material, and that a diffraction pattern can be obtained that indicates the positions of the atoms. Determining the locations of the atoms in a material and their interactions with one another is vital to an understanding of the properties of that material. For his work on neutron diffraction Shull shared the 1994 Nobel Prize in Physics with B. N. Brockhouse.