Lawrence, Ernest O.

Lawrence, Ernest O. (Orlando) (1901–58) physicist; born in Canton, S.D. He began his career at Yale (1925–28), then transferred to the University of California: Berkeley (1928–58). His invention of the cyclotron (1929), which accelerates atomic particles to produce artificial radioactivity fundamental to later applications in nuclear physics and medicine, won him the 1939 Nobel Prize. He produced most of the uranium used in the Hiroshima atomic bomb. The element lawrencium is named for him.