Edwin McMillan was a US nuclear physicist who shared with Glen Seaborg the 1951 Nobel Prize in Chemistry for his discovery of the first transuranic element, number 93, neptunium (1940). McMillan worked on the Manhattan Project developing the atom bomb at Los Alamos, New Mexico, then on the cyclotron with Ernest Lawrence at the University of California at Berkeley. Independently, he and the Soviet physicist Vladimir Veksler (1907–1966) developed the synchrotron, from which they shared the 1963 Atoms for Peace award.