Christopher Hollis Johnson CBE (18 March 1904 - 9 April 1978) was a British chemist and physicist. He worked in weapons research and was part of the technical committee of Tube Alloys, the UK's secret atomic weapon development programme.
He was born in Reading to Agnes Mary Hollis and Ernest Gladstone Johnson. His father was a hosier, outfitter and haberdasher. In 1930, he married Irene Kathleen Gilbert. [1] [2] [3]
Before World War II, he researched valence theory, polarimetry and related optically active compounds. By 1939, he was a senior lecturer in inorganic chemistry at the University of Birmingham. At the time, concerns had grown about the possibility of the creation of an atomic weapon by an aggressive Nazi Germany. Johnson's Birmingham colleague Mark Oliphant directed Rudolf Peierls and Otto Frisch (refugee physicists also at Birmingham) to investigate if indeed such a weapon was feasible and in March 1940 Frisch, using Peierl's formula, got an alarming result which confirmed that a small mass of uranium-235 could have a devastating effect; the Frisch-Peierls memorandum was circulated secretly by Oliphant and immediate action taken to try and secure supplies of uranium ore. What came to be called the MAUD Technical Committee was created in response to the Frisch-Peierls memorandum. As well as a Policy Committee, a Technical Committee contained scientists and engineers mainly from four British universities, Liverpool, Oxford, Cambridge and Birmingham. At Birmingham, the committee was led by Peierls assisted by Johnson, Nobel Prize winner Norman Haworth and, in 1941, Klaus Fuchs, who was later exposed as a Soviet spy. Haworth led the chemists studying the properties of uranium hexafluoride; Johnson's experiments resulted in a paper describing how it attacked various materials. The research, as part of Tube Alloys, was subsumed into the Manhattan Project. [4] [5] [6] [7] [8] [9] [10]
In 1958, Johnson was awarded a CBE for his research. From 1958 to 1964, he was the Director of the Explosives Research and Development Establishment at Waltham Abbey, part of the Ministry of Aviation, when he retired. He died in 1978, aged 74. [11] [12]
Klaus Emil Julius Fuchs was a German theoretical physicist and atomic spy who supplied information from the American, British and Canadian Manhattan Project to the Soviet Union during and shortly after World War II. While at the Los Alamos National Laboratory, Fuchs was responsible for many significant theoretical calculations relating to the first nuclear weapons and, later, early models of the hydrogen bomb. After his conviction in 1950, he served nine years in prison in the United Kingdom, then migrated to East Germany where he resumed his career as a physicist and scientific leader.
Sir James Chadwick, was an English physicist who was awarded the 1935 Nobel Prize in Physics for his discovery of the neutron in 1932. In 1941, he wrote the final draft of the MAUD Report, which inspired the U.S. government to begin serious atom bomb research efforts. He was the head of the British team that worked on the Manhattan Project during World War II. He was knighted in Britain in 1945 for his achievements in physics.
Sir Marcus Laurence Elwin Oliphant, was an Australian physicist and humanitarian who played an important role in the first experimental demonstration of nuclear fusion and in the development of nuclear weapons.
Sir John Douglas Cockcroft, was a British physicist who shared with Ernest Walton the Nobel Prize in Physics in 1951 for splitting the atomic nucleus, and was instrumental in the development of nuclear power.
Otto Robert Frisch FRS was an Austrian-born British physicist who worked on nuclear physics. With Lise Meitner he advanced the first theoretical explanation of nuclear fission and first experimentally detected the fission by-products. Later, with his collaborator Rudolf Peierls he designed the first theoretical mechanism for the detonation of an atomic bomb in 1940.
Tube Alloys was the research and development programme authorised by the United Kingdom, with participation from Canada, to develop nuclear weapons during the Second World War. Starting before the Manhattan Project in the United States, the British efforts were kept classified, and as such had to be referred to by code even within the highest circles of government.
Sir Rudolf Ernst Peierls, was a German-born British physicist who played a major role in Tube Alloys, Britain's nuclear weapon programme, as well as the subsequent Manhattan Project, the combined Allied nuclear bomb programme. His obituary in Physics Today described him as "a major player in the drama of the eruption of nuclear physics into world affairs".
The Quebec Agreement was a secret agreement between the United Kingdom and the United States outlining the terms for the coordinated development of the science and engineering related to nuclear energy and specifically nuclear weapons. It was signed by Winston Churchill and Franklin D. Roosevelt on 19 August 1943, during World War II, at the First Quebec Conference in Quebec City, Quebec, Canada.
K-25 was the codename given by the Manhattan Project to the program to produce enriched uranium for atomic bombs using the gaseous diffusion method. Originally the codename for the product, over time it came to refer to the project, the production facility located at the Clinton Engineer Works in Oak Ridge, Tennessee, the main gaseous diffusion building, and ultimately the site. When it was built in 1944, the four-story K-25 gaseous diffusion plant was the world's largest building, comprising over 5,264,000 square feet (489,000 m2) of floor space and a volume of 97,500,000 cubic feet (2,760,000 m3).
The Frisch–Peierls memorandum was the first technical exposition of a practical nuclear weapon. It was written by expatriate German-Jewish physicists Otto Frisch and Rudolf Peierls in March 1940 while they were both working for Mark Oliphant at the University of Birmingham in Britain during World War II.
The Manhattan Project was a research and development project that produced the first atomic bombs during World War II. It was led by the United States with the support of the United Kingdom and Canada. From 1942 to 1946, the project was under the direction of Major General Leslie Groves of the US Army Corps of Engineers. The Army component of the project was designated the Manhattan District; "Manhattan" gradually became the codename for the entire project. Along the way, the project absorbed its earlier British counterpart, Tube Alloys. The Manhattan Project began modestly in 1939, but grew to employ more than 130,000 people and cost nearly US$2 billion. Over 90% of the cost was for building factories and producing the fissionable materials, with less than 10% for development and production of the weapons.
The MAUD Committee was a British scientific working group formed during the Second World War. It was established to perform the research required to determine if an atomic bomb was feasible. The name MAUD came from a strange line in a telegram from Danish physicist Niels Bohr referring to his housekeeper, Maud Ray.
The S-1 Executive Committee laid the groundwork for the Manhattan Project by initiating and coordinating the early research efforts in the United States, and liaising with the Tube Alloys Project in Britain.
The S-50 Project was the Manhattan Project's effort to produce enriched uranium by liquid thermal diffusion during World War II. It was one of three technologies for uranium enrichment pursued by the Manhattan Project.
Sir Ernest William Titterton was a British nuclear physicist.
The Gen 75 Committee was a committee of the British cabinet, convened by the Prime Minister, Clement Attlee, on 10 August 1945. It was one of many ad hoc cabinet committees, each of which was convened to handle a single issue, and given a prefix of Gen and a number. The purpose of the Gen 75 committee was to discuss and establish the British government's nuclear policy. Attlee dubbed it the "Atom Bomb Committee". It was replaced by an official ministerial committee, the Atomic Energy Committee, in February 1947.
Niels Janniksen Bjerrum was a Danish chemist.
Britain contributed to the Manhattan Project by helping initiate the effort to build the first atomic bombs in the United States during World War II, and helped carry it through to completion in August 1945 by supplying crucial expertise. Following the discovery of nuclear fission in uranium, scientists Rudolf Peierls and Otto Frisch at the University of Birmingham calculated, in March 1940, that the critical mass of a metallic sphere of pure uranium-235 was as little as 1 to 10 kilograms, and would explode with the power of thousands of tons of dynamite. The Frisch–Peierls memorandum prompted Britain to create an atomic bomb project, known as Tube Alloys. Mark Oliphant, an Australian physicist working in Britain, was instrumental in making the results of the British MAUD Report known in the United States in 1941 by a visit in person. Initially the British project was larger and more advanced, but after the United States entered the war, the American project soon outstripped and dwarfed its British counterpart. The British government then decided to shelve its own nuclear ambitions, and participate in the American project.
High Explosive Research (HER) was the British project to develop atomic bombs independently after the Second World War. This decision was taken by a cabinet sub-committee on 8 January 1947, in response to apprehension of an American return to isolationism, fears that Britain might lose its great power status, and the actions by the United States to withdraw unilaterally from sharing of nuclear technology under the 1943 Quebec Agreement. The decision was publicly announced in the House of Commons on 12 May 1948.
Henry Shull Arms was an American and later British physicist and engineer. He worked in the British and Allied programmes to make a nuclear weapon and later developed civilian nuclear reactors in the UK.