Clifford Shull

It’s the birthday of Clifford Shull, who was born 100 years ago in Pittsburgh. Shull earned a PhD in physics from New York University. His first job, during World War II, was to analyze the microstructure of catalysts for oil company Texaco. In 1946 he moved to Oak Ridge National Laboratory, where he developed the use of neutrons produced by nuclear reactors as diffractive probes of condensed matter. Although neutrons are more difficult to produce in abundance than either x rays or electrons, they have two big advantages for diffraction studies: They are neutral and have spin (so they can be used to probe magnetic structure) and they scatter strongly off hydrogen (so they are especially useful for biological samples). Half a century later Shull and fellow neutron scattering pioneer, Bertram Brockhouse, were awarded the Nobel physics prize.

Date in History: 23 September 1915