Ernest Omar Wollan

Ernest O. Wollan, pioneer physicist in neutron diffraction, was born at Glenwood, Minnesota, in 1902. Wollan attended Concordia College and the University of Chicago, where he earned his Ph.D. in 1929 under Arthur Compton in studies of X-ray scattering. Early in his career, Wollan taught physics at North Dakota State College and Washington University, and he conducted important research into cosmic rays in the United States, Europe, and South America. In 1942 he returned to Chicago as part of the Manhattan Project research team to establish radiation monitoring procedures for the safety of personnel; he invented the radiation badge that later became universally adopted. Wollan was present at the start-up of the first nuclear reactor at Stagg Field and recorded gamma ray intensities associated with this dramatic event.

In 1944 Wollan joined the Oak Ridge National Laboratory (ORNL), where he became interested in using neutron beams from the Oak Ridge Graphite Reactor for neutron scattering research. He bombarded material with neutrons from this reactor and studied the scattered neutrons with a modified X-ray diffractometer. He and Clifford G. Shull performed pioneering research that established neutron diffraction techniques as an outstanding method for measuring nuclear properties and for determining atomic and magnetic structures of materials.

Wollan was Associate Director of the ORNL physics division from 1948 to 1964, and he retired in 1967. He served as consultant to ORNL until 1977, when he returned to Minnesota, where he died in 1984.