James Chadwick
Born	October 20, 1891(1891-10-20) Cheshire, England
Died	July 24, 1974 (aged 82) Cambridge, England
Citizenship	United Kingdom
Field	Physics
Institutions	Technical University of Berlin Liverpool University Gonville and Caius College Cambridge University
Alma mater	Victoria University of Manchester University of Cambridge.
Known for	Discovering the neutron and being a member of the Manhattan Project
Notable prizes	Nobel Prize in Physics (1935)

Sir James Chadwick, CH (20 October 1891 – 24 July 1974) was an English physicist and Nobel laureate who is best known for discovering the neutron. Image File history File links No higher resolution available. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... Year 1891 (MDCCCXCI) was a common year starting on Thursday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ... Cheshire (or, archaically, the County of Chester)[1] is a county in North West England. ... For other uses, see England (disambiguation). ... is the 205th day of the year (206th in leap years) in the Gregorian calendar. ... Year 1974 (MCMLXXIV) was a common year starting on Tuesday (link will display full calendar) of the 1974 Gregorian calendar. ... This article is about the city in England. ... For other uses, see England (disambiguation). ... Image File history File links Flag_of_the_United_Kingdom. ... A magnet levitating above a high-temperature superconductor demonstrates the Meissner effect. ... South Side of the main building Main building The Technical University of Berlin (TUB, TU Berlin, German: Technische Universität Berlin) is located in Berlin, Germany. ... The University of Liverpool is a university in the city of Liverpool in the United Kingdom. ... Full name Gonville and Caius College Motto Named after Edmund Gonville & John Caius Previous names Gonville Hall (1348), Gonville & Caius (1557) Established 1348, refounded 1557 Sister College(s) Brasenose College Master Sir Christopher Hum Location Trinity St Undergraduates 468 Postgraduates 291 Homepage Boatclub Gonville and Caius College, Cambridge is a... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the worlds most prestigious universities. ... The Victoria University of Manchester (VUM) was a large university in Manchester in England. ... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the worlds most prestigious universities. ... This article or section does not adequately cite its references or sources. ... The Manhattan Project resulted in the creation of the first nuclear weapons, and the first-ever nuclear detonation, known as the Trinity test of July 16, 1945. ... Image File history File links Nobel_prize_medal. ... Hannes Alfvén (1908–1995) accepting the Nobel Prize for his work on magnetohydrodynamics [1]. List of Nobel Prize laureates in Physics from 1901 to the present day. ... The Order of the Companions of Honour is a British and Commonwealth Order. ... is the 293rd day of the year (294th in leap years) in the Gregorian calendar. ... Year 1891 (MDCCCXCI) was a common year starting on Thursday (link will display the full calendar) of the Gregorian calendar (or a common year starting on Saturday of the 12-day slower Julian calendar). ... is the 205th day of the year (206th in leap years) in the Gregorian calendar. ... Year 1974 (MCMLXXIV) was a common year starting on Tuesday (link will display full calendar) of the 1974 Gregorian calendar. ... Not to be confused with physician, a person who practices medicine. ... The Nobel Prizes (pronounced no-BELL or no-bell) are awarded annually to people who have done outstanding research, invented groundbreaking techniques or equipment, or made outstanding contributions to society. ... This article or section does not adequately cite its references or sources. ...

Biography

James Chadwick was born in Bollington, Cheshire, England on October 20, 1891, the son of John Joseph Chadwick and Anne Mary Knowles. He went to Bollington Cross C of E Primary School, attended Manchester High School, and studied at the Universities of Manchester and Cambridge. In 1913 Chadwick went and worked with Hans Geiger at the Technical University of Berlin. He also worked with Ernest Rutherford. He was in Germany at the start of World War I and would be interned in Ruhleben P.O.W. Camp just outside Berlin. During his internment he had the freedom to set up a laboratory in the stables. With the help of Charles Ellis he worked on the ionization of phosphorus and also on the photo-chemical reaction of carbon monoxide and chlorine.^[1] He spent most of the war years in Ruhleben until Geiger's laboratory interceded for his release. Bollington is a small town [1] in Cheshire, England, north of Macclesfield and east of Prestbury. ... Cheshire (or, archaically, the County of Chester)[1] is a county in North West England. ... The Victoria University of Manchester (VUM) was a large university in Manchester in England. ... The University of Cambridge (often Cambridge University), located in Cambridge, England, is the second-oldest university in the English-speaking world and has a reputation as one of the worlds most prestigious universities. ... Johannes (Hans) Wilhelm Geiger (September 30, 1882 – September 24, 1945) was a German physicist. ... South Side of the main building Main building The Technical University of Berlin (TUB, TU Berlin, German: Technische Universität Berlin) is located in Berlin, Germany. ... Ernest Rutherford, 1st Baron Rutherford of Nelson OM PC FRS (30 August 1871 - 19 October 1937), widely referred to as Lord Rutherford, was a nuclear physicist who became known as the father of nuclear physics. ... Ruhleben P.O.W. Camp was a civilian detention camp during the World War I. It was located in Rubleben, then a village 10 kilometre to the west of Berlin, now a district of the city called Ruhleben-Spandau. ... Sir Charles Drummond Ellis (b. ...

Career

Research at Cambridge

In 1932 Chadwick made a fundamental discovery in the domain of nuclear science: he discovered the particle in the nucleus of an atom that became known as the neutron because it has no electric charge. In contrast with the helium nuclei (alpha particles) which are positively 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. In this way, Chadwick prepared the way towards the fission of uranium 235 and towards the creation of the atomic bomb. For this important discovery he was awarded the Hughes Medal of the Royal Society in 1932, and subsequently the Nobel Prize for Physics in 1935. Later, he found out that a German scientist had discovered the neutron at the same time. But Hans Falkenhagen (Rostock) was afraid of publishing his results. When Chadwick learned of Falkenhagen's discovery, he offered to share the Nobel Prize with him. Falkenhagen, however, modestly refused the honor. The nucleus (atomic nucleus) is the center of an atom. ... This article or section does not adequately cite its references or sources. ... For other uses, see Helium (disambiguation). ... An alpha particle is deflected by a magnetic field Alpha particles or alpha rays are a form of particle radiation which are highly ionizing and have low penetration. ... An induced nuclear fission event. ... Uranium-235 is an isotope of uranium that differs from the elements other common isotope, uranium-238, by its ability to cause a rapidly expanding fission chain reaction, i. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the epicenter. ... The Hughes Medal, named after microphone inventor David Edward Hughes, is one of several medals awarded by the Royal Society, Englands reigning academy of science. ... For other uses, see Royal Society (disambiguation). ... List of Nobel Prize laureates in Physics from 1901 to the present day. ...

Chadwick’s discovery made it possible to create elements heavier than uranium in the laboratory. His discovery particularly inspired Enrico Fermi, Italian physicist and Nobel laureate, to discover nuclear reactions brought by slowed neutrons, and led Otto Hahn and Fritz Strassmann, German radiochemists in Berlin, to the revolutionary discovery of “nuclear fission”, which triggered the development of the atomic bomb. General Name, symbol, number uranium, U, 92 Chemical series actinides Group, period, block n/a, 7, f Appearance silvery gray metallic; corrodes to a spalling black oxide coat in air Standard atomic weight 238. ... Enrico Fermi (September 29, 1901 – November 28, 1954) was an Italian physicist most noted for his work on the development of the first nuclear reactor, and for his contributions to the development of quantum theory, particle physics and statistical mechanics. ... Otto Hahn and Lise Meitner, 1913, at the KWI for Chemistry in Berlin Otto Hahn (March 8, 1879 – July 28, 1968) was a German chemist and received the 1944 Nobel Prize in Chemistry. ... An induced nuclear fission event. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the epicenter. ...

Liverpool

Chadwick became professor of physics at Liverpool University in 1935. As a result of the Frisch-Peierls memorandum in 1940 on the feasibility of an atomic bomb, he was appointed to the MAUD Committee that investigated the matter further. He visited North America as part of the Tizard Mission in 1940 to collaborate with the Americans and Canadians on nuclear research. Returning to England in November 1940, he concluded that nothing would emerge from this research until after the war. In December 1940 Franz Simon, who had been commissioned by MAUD, reported that it was possible to separate the isotope uranium-235. Simon's report included cost estimates and technical specifications for a large uranium enrichment plant. James Chadwick later wrote that it was at that time that he "realised that a nuclear bomb was not only possible, it was inevitable. I had then to start taking sleeping pills. It was the only remedy." The University of Liverpool is a university in the city of Liverpool in the United Kingdom. ... 1935 (MCMXXXV) was a common year starting on Tuesday (link will display full calendar). ... The Frisch-Peierls memorandum was written by Otto Frisch and Rudolf Peierls while they were both working at Birmingham University, England. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the epicenter. ... The Maud Committee was the beginning of the British atomic bomb project, before the United Kingdom joined forces with the United States in the Manhattan Project. ... Sir Henry Tizard, instigator and leader of The Tizard Mission In the late September 1940 during the Battle of Britain in the Second World War, a delegation arrived from the UK in the United States on a mission instigated by Henry Tizard, known as the Tizard Mission. ... Sir Francis Simon was a British scientist and a Fellow of the Royal Society. ... For other uses, see Isotope (disambiguation). ... Uranium-235 is an isotope of uranium that differs from the elements other common isotope, uranium-238, by its ability to cause a rapidly expanding fission chain reaction. ... Enriched uranium is uranium whose uranium-235 content has been increased through the process of isotope separation. ...

He shortly afterward joined the Manhattan Project in the United States, which developed the atomic bombs dropped on Hiroshima and Nagasaki. Chadwick was knighted in 1945. The Manhattan Project resulted in the creation of the first nuclear weapons, and the first-ever nuclear detonation, known as the Trinity test of July 16, 1945. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, 1945, rose some 18 km (11 mi) above the epicenter. ... For other uses, see Hiroshima (disambiguation). ... Nagasaki ) ( ) is the capital and the largest city of Nagasaki Prefecture in Japan. ... The silver Anglia knight, commissioned as a trophy in 1850, intended to represent the Black Prince. ...

Recently discovered documents

In 1940, Chadwick forwarded the work of two French scientists, Hans Von Halban and Lew Kowarski, who worked in Cambridge to the Royal Society. He asked that the papers be held as they were not appropriate for publication during the war. In 2007, the Society discovered the documents during an audit of their archives.^[2] Hans von Halban (Leipzig, 24 January 1908 - Paris, 28 November 1964) was a French physicist, of Austrian-Jewish descent. ... Lew Kowarski was a naturalized French physicist, of Russian descent. ... For other uses, see Royal Society (disambiguation). ...

References

External links

• Chadwick's article in Nature (May 10, 1932: "The Existence of a Neutron")
• Another letter (3 months earlier) from Chadwick to Nature
• Annotated bibliography for Chadwick from the Alsos Digital Library for Nuclear Issues
• Nobel prize Website entry
• Description of Chadwick papers held by Churchill Archives Centre, Cambridge