MAUD Committee facts for kids
The MAUD Committee was a group of British scientists who worked together during World War II. Their main job was to figure out if it was possible to build an atomic bomb. The committee got its unusual name, MAUD, from a strange line in a message sent by a famous Danish scientist named Niels Bohr. He mentioned his housekeeper, Maud Ray, in the message, and people thought it was a secret code!
This committee was started because of a very important paper called the Frisch–Peierls memorandum. It was written in March 1940 by two scientists, Rudolf Peierls and Otto Frisch, who had come to Britain from Nazi Germany. They were working at the University of Birmingham. Their paper suggested that a very small amount of a special type of uranium, called uranium-235, could create a huge explosion, like thousands of tons of TNT.
George Thomson was the leader of the MAUD Committee. The research was spread out among four different universities: the University of Birmingham, University of Liverpool, University of Cambridge, and the University of Oxford. Each university had its own research leader. The scientists looked into different ways to get the special uranium (this is called uranium enrichment). They also studied how to design a nuclear reactor, the features of uranium-235, and a new element called plutonium. They also worked on the ideas behind how a nuclear weapon would work.
After 15 months of hard work, the committee finished two big reports. These reports were called "Use of Uranium for a Bomb" and "Use of Uranium as a Source of Power," and together they were known as the MAUD Report. The reports explained that an atomic bomb was possible and important for the war. Because of these findings, Britain started its own secret nuclear weapons project, code-named Tube Alloys. The MAUD Report was also shared with the United States, which helped kick-start their own efforts, leading to the famous Manhattan Project. Even the Soviet Union learned about the report through their atomic spies, which helped them start their own Soviet atomic bomb project.
Contents
How It Started
Discovering Nuclear Fission
The story of the atomic bomb began with a tiny particle called the neutron. James Chadwick discovered it at the University of Cambridge in February 1932. A couple of months later, his colleagues, John Cockcroft and Ernest Walton, managed to split lithium atoms.
Then, in December 1938, Otto Hahn and Fritz Strassmann in Berlin found something amazing. When they hit uranium with neutrons, they discovered a new element, barium. Hahn wrote to his colleague Lise Meitner. She and her nephew, Otto Frisch, then figured out that the uranium nucleus had actually split apart. They published their discovery in the science journal Nature in 1939. This was a completely new type of atomic breakup, much more powerful than anything seen before. Frisch and Meitner calculated that each split released a huge amount of energy. They called this process "nuclear fission" because it was like how biological cells divide.
Niels Bohr and John A. Wheeler helped explain how nuclear fission worked. Bohr realized that splitting uranium at low energies mainly involved uranium-235, which is only a tiny part (0.7%) of natural uranium. Splitting at high energies involved the more common uranium-238. In April 1939, Frédéric Joliot-Curie and his team in Paris suggested that a nuclear chain reaction might be possible. This meant that one split atom could cause others to split, creating a continuous reaction. Many scientists then realized that, in theory, an incredibly powerful explosive could be made. The idea of an "atomic bomb" was already known to the British public from a 1913 novel by H. G. Wells called The World Set Free.
The Frisch–Peierls Memorandum
At the University of Birmingham, Professor Mark Oliphant gave a special task to Frisch and Rudolf Peierls. These two scientists were refugees from Germany and couldn't work on secret radar projects because of security rules. A scientist named Francis Perrin had calculated that a huge amount of uranium, about 40 tons, would be needed to start a chain reaction. Peierls tried to simplify the problem by using fast neutrons. He also thought a very large amount of uranium would be needed.
However, Niels Bohr had suggested that uranium-235 was much more likely to split even with low-energy neutrons. Frisch started trying to get pure uranium-235 using a method called thermal diffusion. It was slow work because they didn't have the right equipment. Frisch then wondered what would happen if he could get a sphere of pure uranium-235. When he used Peierls' math, he got a shocking answer: less than a kilogram would be needed!
In March 1940, Frisch and Peierls wrote their important paper, the Frisch–Peierls memorandum. They reported that a bomb with just five kilograms of uranium-235 could be as powerful as several thousand tons of dynamite. Even a one-kilogram bomb would be very strong. They also worried about the radioactive fallout and wondered if Britain would find such a weapon morally acceptable.
Oliphant showed the memorandum to government officials. They quickly took action. They asked the government to secure uranium supplies so the Germans couldn't get them. British spy agencies were asked to investigate German scientists. They also checked with American scientists, who at the time didn't think military uses were likely.
How the Committee Was Organized
A committee was formed because of the Frisch–Peierls memorandum. Its first meeting was on April 10, 1940, in London. The first members were Thomson, Chadwick, Cockcroft, Oliphant, and Philip Moon. Other scientists joined later. The committee was originally called the Thomson Committee, after its chairman, but they soon changed it to a less obvious name: the MAUD Committee.
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Many people thought MAUD was an acronym, like a secret code word made from the first letters of other words. But it wasn't! The name came from a strange message Niels Bohr sent to Frisch on April 9, 1940, the day Germany invaded Denmark. The message ended with "Tell Cockcroft and Maud Ray Kent." At first, they thought it was a secret code about radium or other atomic secrets. But when Bohr returned to England in 1943, they found out he was just sending a message to John Cockcroft and his housekeeper, Maud Ray, who lived in Kent. So, the committee was named the MAUD Committee. Even though the letters didn't stand for anything, it was officially the MAUD Committee, not just the Maud Committee.
Because the project was top secret, only British-born scientists were allowed on the main committee. Even though Peierls and Frisch had made huge contributions, they couldn't be full members at first because they were from Germany. In September 1940, a Technical Sub-Committee was formed, and Peierls and Frisch were members of that. Later, in March 1941, two new committees replaced the original ones: the MAUD Policy Committee and the MAUD Technical Committee. These new committees had clear rules about what they should do.
The MAUD Policy Committee was a small group that oversaw the research and made recommendations. The MAUD Technical Committee focused on the scientific problems, recommended experiments, and made sure different research groups worked together. George Thomson led both committees.
What They Did
The MAUD Committee's research was divided among four universities in England: the University of Birmingham, the University of Liverpool, the University of Cambridge, and the University of Oxford. At first, the universities paid for the research themselves. But in September 1940, the government started providing money. The government also ordered five kilograms of uranium hexafluoride from a company called ICI. This was a gas needed for separating uranium isotopes.
There was also a shortage of scientists, as many were busy with other war work. The universities had to hire many scientists who were not British citizens. At first, the government worried about security because many of these scientists were from countries that were enemies or had been taken over. But eventually, the government allowed them to work on the project and even helped them get security clearances. This meant that some of the biggest wartime secrets were trusted to scientists who couldn't work on other secret projects.
University of Liverpool
At the University of Liverpool, the MAUD Committee's work was led by James Chadwick. His team included Frisch and others. They focused on separating uranium isotopes using a method called thermal diffusion, which was mentioned in the Frisch–Peierls memorandum.
This method works because when two gases are mixed and heated, the heavier gas moves to the cold side, and the lighter gas moves to the warm side. This was first shown in Germany in 1938. The advantage of this method was that it was simple and had no moving parts. But it took a long time, used a lot of energy, and needed very high temperatures, which could be a problem for uranium hexafluoride.
Another important task at Liverpool was measuring how easily uranium-235 would split when hit by neutrons. Frisch and Peierls' calculations depended on this. They had thought that almost every hit would cause a split. But new information from American scientists suggested it was much harder to split.
Since pure uranium-235 wasn't available, the experiments at Liverpool used natural uranium. The results were not clear, but they seemed to support Frisch and Peierls' ideas. By March 1941, an American scientist named Alfred Nier managed to produce a tiny amount of pure uranium-235. A team in the United States then measured how easily it split. The final result was that it was harder to split than Frisch and Peierls had thought, but the amount needed for a bomb was still only about eight kilograms.
Meanwhile, a scientist named Maurice Pryce studied how long a chain reaction in an atomic bomb would last before the bomb blew itself apart. He calculated that the main part of the chain reaction would be over in a tiny fraction of a second. Even if only 1 to 10 percent of the uranium split, a bomb could release as much energy as 180,000 times its weight in TNT.
University of Oxford
At the University of Oxford, the MAUD Committee's work was led by Franz Simon. He was a German scientist who was allowed to join because Peierls said he had already started research on isotope separation. The Oxford team had many non-British scientists. They focused on separating isotopes using a method called gaseous diffusion.
This method uses a rule that says lighter gas molecules pass through tiny holes faster than heavier ones. So, if you have a mixture of two gases, the gas that comes out through a porous barrier will have more of the lighter molecules. Simon's team experimented with copper mesh as the barrier. They used a mixture of carbon dioxide and water vapor to test it because uranium hexafluoride was hard to get and dangerous to handle.
In December 1940, Simon wrote a report about building a plant to separate uranium. He described a huge factory that could produce one kilogram of 99% pure uranium-235 every day. This plant would need a massive area, weigh 70,000 tons, and use a lot of electricity. He estimated it would take 12 to 18 months to build and cost about £4 million. Simon concluded that the separation could be done and that the project was worth the time, money, and effort.
University of Cambridge
At the University of Cambridge, the MAUD Committee's work was led by Bragg and John Cockcroft. Their team included several French scientists, Hans von Halban and Lew Kowarski, who had brought their valuable supply of heavy water to England after Germany invaded France. The heavy water was first kept in a prison, then secretly stored in the library at Windsor Castle. The French scientists moved to Cambridge and did experiments that clearly showed a nuclear chain reaction could happen in a mix of uranium oxide and heavy water.
Halban and Kowarski also suggested that slow neutrons could be absorbed by uranium-238, which would then turn into uranium-239. An American paper published in June 1940 said that this uranium-239 then changed into a new element, element 93, and then into element 94, which was called plutonium. This new element, plutonium, could also be split by neutrons, just like uranium-235. This was exciting because plutonium could be made from the more common uranium-238 in a nuclear reactor, and it could be separated using chemicals, avoiding the difficult process of isotope separation.
A scientist named Nicholas Kemmer suggested naming element 93 "neptunium" and element 94 "plutonium," following the planets after Uranus (which uranium was named after). Later, Americans independently chose the same names. Other scientists also theorized that another new isotope, uranium-233, could be made from thorium and might also be useful for fission. In addition, Eric Rideal studied isotope separation using centrifugation, a method that spins materials very fast to separate them.
University of Birmingham
At the University of Birmingham, the MAUD Committee's work was led by Rudolf Peierls. His team included chemists who studied the properties of uranium hexafluoride. This gas was good because fluorine only has one isotope, so any weight difference in the gas molecules would be due to different uranium isotopes.
However, uranium hexafluoride was not easy to work with. It became solid at 120 degrees Fahrenheit, was corrosive, and reacted with many things, including water. This made it difficult and dangerous to handle. The chemists couldn't find another uranium gas. So, the government asked ICI to produce uranium hexafluoride on a large scale. Even though it was expensive, the order was placed in December 1940. ICI also looked into ways to produce pure uranium metal.
Peierls and his team worked on the theoretical problems of how a nuclear bomb would work. They were in charge of figuring out the technical details of the bomb. Peierls and Klaus Fuchs also looked at all the experimental data from the other universities. By the end of summer 1940, Peierls thought gaseous diffusion was a better method than thermal diffusion for separating isotopes.
An American scientist, George Kistiakowsky, had suggested that a nuclear weapon wouldn't do much damage because most of its energy would just heat the air. Peierls, Fuchs, and others worked out the physics to show that Kistiakowsky was wrong. They proved that a nuclear explosion would indeed create a powerful blast wave.
The Reports
The MAUD Committee's final report was first written by Thomson in June 1941. It was then shared with the committee members for discussion. After a lot of editing, mainly by Chadwick, it was split into two reports. The first was "Use of Uranium for a Bomb," and the second was "Use of Uranium as a Source of Power." These reports brought together all the research and experiments the MAUD Committee had done.
The first report began by saying:
We started this project with more doubt than belief, but we felt it had to be investigated. As we continued, we became more and more convinced that releasing atomic energy on a large scale is possible and that it could be a very powerful weapon of war. We now believe it will be possible to make an effective uranium bomb. A bomb with about 25 pounds of active material would have the same destructive power as 1,800 tons of TNT. It would also release a lot of radioactive substances, making areas near the explosion dangerous for a long time.
The first report concluded that a bomb was possible. It described the technical details and suggested specific steps for developing it, including how much it would cost. A factory to produce one kilogram of uranium-235 per day was estimated to cost £5 million. It would need many skilled workers, who were also needed for other war efforts. The report said the bomb could be ready in as little as two years. The damage it would cause was compared to the Halifax explosion in 1917, which had destroyed everything within a quarter-mile radius. The report also warned that Germany was interested in heavy water, and even though this wasn't useful for a bomb, Germany might also be working on a bomb.
The second report was shorter. It suggested that Halban and Kowarski should move to the US, where there were plans to make heavy water on a large scale. It also said that plutonium might be better than uranium-235, and that plutonium research should continue in Britain. It concluded that controlling uranium fission could create heat energy for machines and produce large amounts of radioactive materials that could replace radium. Heavy water or graphite could be used to slow down fast neutrons in a reactor. However, the committee felt that while nuclear reactors had a lot of promise for peaceful uses in the future, they weren't worth focusing on during the current war.
What Happened Next
United Kingdom
After the MAUD Committee's report, Britain started its own nuclear weapons program. To manage this effort, a new department was created with a misleading name for security: Tube Alloys. Sir John Anderson became the minister in charge, and Wallace Akers from ICI was appointed its director.
Tube Alloys and the American Manhattan Project shared information, but they didn't fully combine their efforts at first. This was supposedly due to worries about American security. Ironically, it was the British project that had already been spied on by the Soviet Union. One of the most important spies at this time was John Cairncross, who worked for a government minister. Cairncross gave the Soviet spy agency (NKVD) information from the MAUD Committee.
Britain didn't have as many people or resources as the United States. So, even though Tube Alloys had a strong start, it fell behind the American project. The British thought about building an atomic bomb without American help, but it would have been incredibly expensive, would have disrupted other important war projects, and probably wouldn't have been ready in time to affect the war in Europe.
At the Quebec Conference in August 1943, British Prime Minister Winston Churchill and American President Franklin D. Roosevelt signed an agreement that merged the two national projects. This agreement created the Combined Policy Committee to coordinate their efforts. Later, another agreement in 1944 extended their cooperation into the time after the war.
A British team led by Akers helped develop the gaseous diffusion technology in New York. Another team, led by Oliphant, helped with the electromagnetic separation process in California. John Cockcroft became the director of the joint British-Canadian Montreal Laboratory. A British team at the Los Alamos Laboratory, led by Chadwick and later Peierls, included many of Britain's top scientists. Chadwick made sure that British scientists fully participated and worked well with the Americans.
United States
In response to a letter from scientists Albert Einstein and Leo Szilard in 1939, President Franklin D. Roosevelt created an Advisory Committee on Uranium. This committee focused on using slow fission to produce power, but they also became more interested in separating isotopes. In June 1941, Roosevelt created the Office of Scientific Research and Development (OSRD), led by Vannevar Bush, who reported directly to the President. The Uranium Committee became the S-1 Section of the OSRD for security reasons.
Bush asked Arthur Compton, a Nobel Prize winner, and the National Academy of Sciences to study the matter. Their report in May 1941 supported a stronger effort but didn't go into detail about designing a bomb. Information from the MAUD Committee came from British scientists visiting the United States and from American observers at MAUD Committee meetings. Cockcroft reported that the American project was behind the British one and moving too slowly.
Britain was already at war and felt the atomic bomb was urgent, but the US was not yet in the war. It was Mark Oliphant who really pushed the American program into action. He flew to the United States in August 1941, supposedly to talk about radar, but really to find out why the US was ignoring the MAUD Committee's findings. Oliphant discovered that the American committee leader, Lyman Briggs, had put the MAUD reports in his safe and hadn't shown them to his committee members. Oliphant was shocked and upset.
Oliphant met with the S-1 Section. Samuel K. Allison, a new committee member, remembered Oliphant saying "bomb" very clearly. Oliphant told them they had to focus all their efforts on the bomb and nothing else. He said the bomb would cost $25 million, and Britain didn't have the money or people, so it was up to the Americans.
Oliphant then visited his friend Ernest Lawrence, an American Nobel Prize winner, to explain how urgent the situation was. Lawrence contacted Compton and James B. Conant, who received a copy of the final MAUD Report from Thomson in October 1941. Other American scientists were sent to the UK to get more information. In January 1942, the OSRD was given the power to start large engineering projects, not just research. Without the help of the MAUD Committee, the Manhattan Project would have started months later. Instead, they could immediately begin thinking about how to build a bomb, not just whether it was possible. On July 16, 1945, the Manhattan Project set off the first atomic bomb in the Trinity nuclear test.
Soviet Union
The Soviet Union received secret details of British research from its atomic spies, including Klaus Fuchs and John Cairncross. Lavrentiy Beria, the head of the Soviet secret police (NKVD), gave a report to Joseph Stalin, the leader of the Soviet Union, in March 1942. This report included the MAUD reports and other British documents passed by Cairncross. In 1943, the NKVD got another copy of the MAUD Committee's final report. This led Stalin to order the start of a Soviet atomic bomb program, even though it had very limited resources at first. Igor Kurchatov was appointed director of this new program later that year. Six years later, on August 29, 1949, the Soviet Union tested its own atomic bomb.
