Sir James Chadwick, F.R.S.

Abstract

SIR JAMES CHADWICK has been pre-elected Master of Gonville and Caius College, Cambridge, of which he has been a fellow and more lately an honorary fellow. Sir James began his scientific work under Rutherford in Manchester ; after studying in the University of Berlin he was interned in Germany during the First World War, and there continued his scientific researches. When Rutherford moved to Manchester, Chadwick joined him and took part in Rutherford‘s classical researches on the disintegration of elements by α-particles. With Bieler and later with Rutherford he studied the scattering of α-particles by hydrogen and heavier nuclei, and from these experiments determined the law of force around atomic nuclei. He became assistant director of research under Rutherford at Cambridge, and as such was responsible for the training of Rutherford‘s young research students and for the satisfaction of their modest needs. Many nuclear physicists will remember the attic of the Cavendish equipped with ancient vacuum pumps, gold-leaf electroscopes and the simple apparatus for counting α-particles which was then the main tool of nuclear research. The discovery of the neutron in 1932, followed by the photodisintegration of the deuteron (with Goldhaber) and the creation of electron pairs by γ-rays (with Blackett and Occhialini), marked the peak of Chadwick‘s experimental work. In 1935 he was appointed Lyon Jones professor of physics in the University of Liverpool, and at once embarked on the construction of a 36-in. cyclotron, completing this just prior to the Second World War.