Robert Lyster Thornton

Who was Robert Lyster Thornton?

Robert Lyster Thornton, was born at Wooton, Bedfordshire, England, the son of a mechanical engineer, Dudley L. Thornton, and his wife Katherine Foster. He was educated in Canada, where his family went in his youth, his father being employed by the Canadian Pacific Railway. He attended McGill University for seven years, earning the B.Sc. degree in 1930 and obtaining the Ph.D. degree in physics, under the sponsorship of Stuart Foster, in 1933. His thesis research was on atomic spectroscopy and the Stark effect, an area successfully cultivated by his mentor.

Thornton came to the Lawrence Radiation Laboratory of the University of California at Berkeley in 1933 and most of his later career was connected with that Laboratory where he worked with Professor Ernest Lawrence, the inventor of the cyclotron. The 1930s were years of intense cyclotron development at Berkeley under Lawrence's leadership and Thornton became a prominent member of his team. Thornton worked initially on the 12-inch and 37-inch cyclotrons at Berkeley and on design of the 60-inch cyclotrons.

Toward the end of the 1930s several universities wanted to acquire a cyclotron and turned to Lawrence who often sent detailed plans to those who wanted to build one and loaned one of his collaborators to help with the work. Lawrence sent Thornton to the University of Michigan in Ann Arbor to lead in the construction of a cyclotron, and where he was also an instructor in Physics from 1936 to 1938. During 1938-1939 he worked with physicist D.R. Colson to show the first cloud chamber picture of uranium fusion.