James Chadwick

Sir James Chadwick
Sir James Chadwick c. 1945
Born	James Chadwick (1891-10-20)October 20, 1891 Cheshire,England
Died	24 July 1974(1974-07-24)(aged 82) Cambridge,England
Nationality	British
Citizenship	United Kingdom
Education	University of Manchester University of Cambridge
Known for	Discovery of the neutron
Awards	Nobel Prize in Physics,1935Nobel Prize in Physics(1935) Franklin Medal(1951)
Scientific career
Fields	Physics
Institutions	Technical University of Berlin University of Liverpool Gonville and Caius College University of Cambridge Manhattan Project
Academic advisors	Ernest Rutherford Hans Geiger
Doctoral students	Maurice Goldhaber Ernest C. Pollard Charles Drummond Ellis

SirJames ChadwickCHFRS,(20 October 1891 – 24 July 1974) was anEnglishphysicistandNobel Prizewinner who is best known for discovering theneutron.

Biography

James Chadwick was born inBollington,Cheshire,England. He went toManchester High School,and studied at the Universities ofManchesterandCambridge. In 1913, Chadwick went toBerlininGermanyto work with the scientistHans Geiger.He also worked withErnest Rutherford.He was still in Germany when World War I broke out and he was interned inRuhleben P.O.W. Campjust outside Berlin. In the camp, which had more than 5,000 detainees (prisoners of war) had been a horseracetrack.There were stables, each with 27 horse boxes. The detainees lived in these boxes. The detainees were allowed to do things to keep themselves busy. Chadwick worked with a young scientist calledCharles Ellis.Together they set up alaboratoryin the stables where they worked on theionisationofphosphorusand also on thephotochemicalreaction ofcarbon monoxideand chlorine.

Career

Research at Cambridge

After the war, Chadwick returned to Cambridge where he worked withErnest Rutherford,studying the emission ofgamma raysfromradioactivematerials. They also studied thetransmutationof elements bybombardingthem withalpha particles,and investigated the nature of theatomic nucleus.

In 1932 Chadwick made a very important discovery: he discovered the particle in the nucleus of an atom that became known as theneutronbecause it has no electric charge. In contrast with theheliumnuclei (alpha particles) which are positively charged, and therefore repelled by the strong electrical forces in the nuclei ofheavy atoms,this new tool inatomic disintegrationneed not overcome any electric barrier and is capable of penetrating and splitting the nuclei of even the heaviest elements. In this way, Chadwick prepared the way towards thefissionofuranium 235and towards the creation of theatomic bomb.For this important discovery he was awarded theHughes Medalof theRoyal Societyin 1932, and later theNobel Prizefor Physics in 1935. He was also nicknamed "Jimmy Neutron"because of his discovery of the neutron.

Liverpool

Chadwick became professor of physics atLiverpool Universityin 1935. He worked on the possibility of anatomic bomb.Later he realized that the nuclear bomb really was going to be made. He found it very frightening that the science he had been working on could lead to such a terrible weapon. He started to take sleeping pills.

He joined theManhattan Projectin the United States, which developed theatomic bombsdropped onHiroshimaandNagasaki.Chadwick wasknightedin 1945.

Return to Cambridge

After the war, Chadwick moved to Cambridge University as master of Gonville and Caius College.

He died inCambridgeon 24 July 1974.

Other websites

• Annotated bibliography for James Chadwick from the Alsos Digital Library for Nuclear IssuesArchived2019-02-17 at theWayback Machine
• Nobel prize Website entry
• The Papers of Sir James Chadwickare held at theChurchill Archives Centrein Cambridge and are accessible to the public.