Birth of the 1935 Nobel Physics laureate,
Sir James Chadwick, English physicist
who won the award for discovering the neutron.
James Chadwick was
born in Cheshire, England, on 20th October, 1891, the son of
John Joseph Chadwick and Anne Mary Knowles. He attended Manchester
High School prior to entering Manchester University in 1908;
he graduated from the Honours School of Physics in 1911 and
spent the next two years under Professor (later Lord) Rutherford
in the Physical Laboratory in Manchester, where he worked on
various radioactivity problems, gaining his M.Sc. degree in
1913 That same year he was awarded the 1851 Exhibition Scholarship
and proceeded to Berlin to work in the Physikalisch Technische
Reichsanstalt at Charlottenburg under Professor H. Geiger.
During World War I, Chadwick
was interned in the Zivilgefangenenlager, Ruhleben. After the
war, in 1919, he returned to England to accept the Wollaston
Studentship at Gonville and Caius College, Cambridge, and to
resume work under Rutherford, who in the meantime had moved
to the Cavendish Laboratory, Cambridge. Rutherford had succeeded
that year in disintegrating atoms by bombarding nitrogen with
alpha particles, with the emission of a proton. This was the
first artificial nuclear transformation. In Cambridge, Chadwick
joined Rutherford in accomplishing the transmutation of other
light elements by bombardment with alpha particles, and in making
studies of the properties and structure of atomic nuclei.
Chadwick was elected Fellow of
Gonville and Caius College (1921-1935) and became Assistant
Director of Research in the Cavendish Laboratory (1923). In
1927 he was elected a Fellow of the Royal Society.
In 1932, Chadwick made a fundamental
discovery in the domain of nuclear science: he proved the existence
of neutrons - elementary particles devoid of any electrical
charge. In contrast with the helium nuclei (alpha rays) which
are charged, and therefore repelled by the considerable electrical
forces present in the nuclei of heavy atoms, this new tool in
atomic disintegration need not overcome any electric barrier
and is capable of penetrating and splitting the nuclei of even
the heaviest elements. Chadwick in this way prepared the way
towards the fission of uranium 235 and towards the creation
of the atomic bomb.
Chadwick remained at Cambridge
until 1935 when he was elected to the Lyon Jones Chair of Physics
in the University of Liverpool. From 1943 to 1946 he worked
in the United States as Head of the British Mission attached
to the Manhattan Project for the development of the atomic bomb.
He returned to England and, in 1948, retired from active physics
and his position at Liverpool on his election as Master of Gonville
and Caius College, Cambridge. He retired from this Mastership
in 1959. From 1957 to 1962 he was a parttime member of the United
Kingdom Atomic Energy Authority.
Chadwick has had many papers
published on the topic of radioactivity and connected problems
and, with Lord Rutherford and C. D. Ellis, he is co-author of
the book Radiations from Radioactive substances (1930).
In 1925, Chadwick married Aileen
Stewart-Brown of Liverpool. They had twin daughters, and lived
at Denbigh, NorthWales. His hobbies included gardening and fishing.
Prof. Chadwick died on 24 July 1974