John Douglas Cockcroft was a British physicist and recipient of the 1951 Nobel Prize in Physics.
He was a member of the Tizard Mission to the United States in the autumn of 1940. He was later appointed Head of the Air Defence Research and Development Establishment. In 1944 he went to Canada to take charge of the Canadian Atomic Energy project and became Director of the Montreal and Chalk River Laboratories.
Cockcroft designed the Cockcroft-Walton generator in 1932, which established the importance of accelerators in nuclear research, technology that would help the Manhattan Project succeed. During World War II, Cockcroft took up a war-time appointment as Assistant Director of Scientific Research in the Ministry of Supply and started to work on the application of radar to coast and air defence problems in 1939.
He was awarded a 1951 Nobel Prize in Physics for his pioneering use of particle accelerators in studying the atom. For information about Cockcroft's scientific achievements, visit the Nobel Prize website.