The Manhattan Project or more formally, the Manhattan Engineering District, was a research and development project in World War II to develop the first nuclear weapons. The project is being led by the United States with assistance from Great Britain and Canada. His research was orchestrated by the American physicist Julius Robert Oppenheimer, and overall by General Leslie R. Groves after it became clear that weapons based on nuclear fission could be developed and that Nazi Germany was also developing similar weapons.
Although the project involved more than 30 different research and production sites, the Manhattan Project was largely carried out in three classified scientific sites established by eminent domain powers: Hanford, Washington, Los Alamos, New Mexico, and Oak Ridge, Tennessee. The Los Alamos National Laboratory is built on a "mesa" that was previously home to the Los Alamos Ranch School, a private male residential school specializing in outdoors and horses. The Hanford site, which grows to nearly 1,000 square miles (2,600 km²), takes over irrigated rice fields, orchards, railroads and two farming communities, Hanford and White Bluffs. The Oak Ridge facility covers more than 60,000 acres (243 km²) of several farming communities. Some Tennessee families were given two weeks to vacate the family farms they had lived on for generations.
The whereabouts of the Los Alamos, Oak Ridge, and Hanford locations were kept secret until the end of WWII.
The Manhattan Project resulted in the design, production, and detonation of three nuclear bombs in 1945. The first, using plutonium made in Hanford, was tested on July 16 at the Trinity Site, the world's first nuclear test, near Alamogordo, New Mexico. The second, a uranium bomb called Little Boy was detonated on August 6 in the city of Hiroshima, Japan. The third, a plutonium bomb called Fat Man, was detonated on August 9 over the Japanese city of Nagasaki.
Its main locations still exist today as the Hanford Site, Los Alamos National Laboratory, Oak Ridge National Laboratory, National Security Complex and several other factories.
In 1945, the Project employed more than 130,000 people at its peak and cost nearly US $ 2 billion. (20 billion in 2004 dollars under the ICP.
In the period between World War I and World War II, the United States has risen to prominence in nuclear physics, driven by the work of several local immigrants and physicists. These scientists have developed basic tools for nuclear research - cyclotrons and other particle accelerators - and have used these new tools to discover new substances, including radioisotopes such as Carbon-14.
The original idea of nuclear energy
Enrico Fermi recalls the start of the project in a speech given in 1954 when he retired as President of the American Physical Society.
I remember very well the first month, January 1939, when I started working at the Pupin Laboratory because things happened so fast. In that period, Niels Bohr was still teaching at Princeton University and I remember one afternoon Willis Lamb came back very excited and said that Bohr had leaked some big news. The big news is about the discovery of nuclear fission and an outline of its interpretation. Later that month, there were several meetings in Washington where the importance of the new discovery was discussed in "semi-jocular" talks as a possible source of nuclear power.
The nuclear scientists Leó Szilárd, Edward Teller and Eugene Wigner (all Jewish refugees from Hungary because of Hitler) believed that the energy released in nuclear fission could be used in bombs by Germany. They persuaded Albert Einstein, one of the world's most famous scientists and also a Jewish refugee, to warn President Franklin D. Roosevelt of this danger in a letter on August 2, 1939 drafted by Szilárd. In response to this warning Roosevelt pushed for further research into the national security implications of nuclear fission. After the Hiroshima bombing, Einstein later commented "I was able to burn my hand for writing letters to Roosevelt." Ankatan Laut awarded the first atomic energy funding of $ 6,000 for the frafite experiment, which grew into the Manhattan Project under the scientific leadership of J. Robert Oppenheimer and Enrico Fermi.
Roosevelt created the ad hoc Uranium Committee under the chairmanship of National Bureau of Standards chairman Lyman Briggs. He started a small research program in 1939 at the Naval Research Laboratory in Washington, where physicist Philip Abelson examined the separation of uranium isotopes. At Columbia University the Italian-born nuclear physicist Enrico Fermi made a nuclear reactor prototype using various configurations of graphite and uranium. On October 9, 1941 Roosevelt authorized the development of nuclear weapons.
Vannevar Bush, director of the Carnegie Institution Washington, organized the National Defense Research Committee in 1940 to mobilize the scientific resources of the United States to support war.
New laboratories were created, including the Radiation Laboratory at the Massachusetts Institute of Technology, which helped develop the radar, and the Underwater Sound Laboratory in San Diego, which developed sonar.
The National Defense Research Council (NDRC) also took over the uranium project. In 1940, Bush and Roosevelt created the Office of Scientific Research and Development to build on these efforts.
The Uranium project made no progress in the spring of 1941, when word came from a British recount by Otto Frisch and Fritz Peierls. The report, prepared by the MAUD Committee, which is a sub-committee for the “Scientific Survey of Air Warfare” under G.P. Thomson, professor of physics at Imperial College, London, demonstrated that a very small amount of the fissile isotope of uranium, U-235, could produce an explosion equivalent to several hundred thousand tons of TNT.
The National Academy of Sciences proposed a full-fledged effort to build nuclear weapons, Bush created a special committee, the S-1 Committee, to guide the effort. This happened the day before Japan attacked Pearl Harbor, on December 7, 1941, and meant the start of war for the United States.
Scientists in the physics departments of the University of Chicago Metallurgical Laboratory, University of California Radiation Laboratory and Columbia University, are accelerating their work to prepare nuclear material for a weapon. They must learn to separate Uranium 235 from raw uranium ore (mostly from Uranium 238), and they must also be able to how to create plutonium, a very rare element, by bombing natural uranium (U-238) in a reactor with neutrons produced by uranium 235. Beginning in 1942, large plants were created to produce Uranium 235 at the Oak Ridge National Laboratory in Tennessee and to produce plutonium at the Hanford Site outside Richland, Washington.
When the United States entered WWII in December 1941, several projects were under way to investigate the separation of fissable uranium 235 from uranium 238, the manufacture of plutonium, and the possible nuclear stockpile and detonation.
Physicist and Nobel laureate Arthur Holly Compton set up the Metallurgical Laboratory at the University of Chicago in early 1942 to study plutonium and fission deposits. Compton asked Dr. J. Robert Oppenheimer of the University of California to take charge of research in fast neutron counting, essential to the possibility of a nuclear weapon. John Manley, a physicist at the Metallurgical Laboratory at the University of Chicago, was assigned to help Dr. Oppenheimer sought answers by coordinating and contacting several groups of experimental physicists scattered throughout the country.
In the spring of 1942, Oppenheimer and Robert Serber of the University of Illinois worked on the problem of neutron diffusion (how neutrons move in a chain reaction) and hydrodynamics (how explosions produced by chain reactions behave).
To review the results of this work and the general theory of physical reactions, Oppenheimer undertook a summer study at the University of California, Berkeley in June 1942. The Theoretic Hans Bethe, John Van Vleck, Edward Teller, Felix Bloch, Emil Konopinski, Robert Serber, Stanley S. Frankel , and Eldred C. Nelson (the last three were former Oppenheimer students) concluded that a fission bomb could occur. These scientists suggest that the reaction can be initiated by generating a critical mass - a sufficient number of nuclear explosions to withstand it - either by firing two subcritical masses of plutonium or uranium 235 together or by destroying ("imploding") an empty sphere made of the material with a large explosive blanket. (Serber gives Tolman the credit for the initial idea of implotion.) Until the numbers are known, only this can be done.
Teller saw another possibility: By surrounding the fission bomb with deuterium and tritium, a much more powerful "super bomb" could be created. This concept is based on research into energy production in stars made by Bethe before the war. When the detonation waves from a fission bomb travel through a mixture of deuterium and tritium nuclei, they fuse together to produce more energy than fission can produce, in the process of nuclear fusion, such as diffusion in the sun to create light and heat.
Bethe was skeptical, and Teller pushed hard for his "super bomb," and proposed scheme after scheme, Bethe rejected all of them. The idea is to be put aside when the fission bomb, and the war, is over. The "super bomb", or thermonuclear device, was produced after the war and tested in 1952, after the political war between Teller and Oppenheimer, which ended in the defeat of Oppenheimer who lost his official status, and used a method different from Teller's idea, which Bethe was right to reject. )
Teller also raised the possibility that an atomic bomb could "ignite" the atmosphere, due to a hypothetical fusion reaction of nitrogen nuclei. Bethe showed that, according to Serber, theoretically this could not happen; in his book The Road from Los Alamos. Bethe says that a refutation written by Kononpinski, C. Marvin, and Teller in the LA-602 report (disclosed in February 1973), suggests impossible. According to Serber, Oppenheimer informed Arthur Compton, who couldn't keep quiet. Then it goes into a document that goes to Washington "leading to the" never given rest "question. According to Bethe, this chaos came back in 1975 when it appeared in a magazine article by H.C. Dudley, who got this idea from a report by Pearl Buck from an interview he had with Arthur Compton in 1959, in which he didn't fully understand Compton! This anxiety never cleared the minds of some until the Trinity test; even so if Bethe was wrong, we would never know.
The summer conference, the results of which Serber later summarized in "The Los Alamos Primer" (LA-1 online), provided the original theoretical basis for the design of the atomic bomb, which later became a major task at Los Alamos during the war, and the H-bomb idea. , which haunted the Laboratory in the postwar period.
Measurement of the interaction of fast neutrons with the material in a bomb is very important because the number of neutrons produced in the fission of uranium and plutonium must be known, and because the substances surrounding today's nuclear material have the ability to reflect, or scatter, the neutrons back into the chain reaction before they explode in order. to increase the energy produced. Therefore, the neutron dispersion characteristics of the material must be measured in order to find the best reflector.
Estimating the power of an explosion requires knowledge of many other nuclear properties, including the junctions (a measure of the probability of an encounter between particles producing a determined effect) for nuclear neutron processes in uranium and other elements. Fast neutrons could only be produced by particle accelerators, which were still an uncommon tool in the physics department in 1942.
Better coordination is urgently needed. In September 1942, the difficulties involved with conducting preliminary research on nuclear weapons at universities spread across the country indicated the need for a laboratory built for this purpose only. This need is overshadowed by the demand for factories to produce uranium-235 and plutonium - the diffuse materials that provide nuclear explosives.
Vannevar Bush, the civilian chief of the Office of Scientific Research and Development (OSRD), asked President Roosevelt to commission a large-scale operation that was connected with a growing nuclear weapons project for the military. Roosevelt chose the Army to work with OSRD on building a production plant. The Army Corps of Engineers chose Col. James Marshall to oversee the construction of a factory to separate uranium isotopes and the production of plutonium for the bomb.
OSRD scientists have tried several methods for producing plutonium and separating uranium-235 from uranium, but none of these processes are ready for production - only microscopic amounts are provided.
Only one way - electromagnetic separation, which has been developed by Ernest Lawrence at the University of California Radiation Laboratory at the University of California, Berkeley - looks convincing at the time for large-scale production. But scientists cannot stop studying other potential methods of producing fissable materials, because the process is very expensive and because it is so unlikely that it will produce enough material before the war ends.
Marshall and his deputy, Col. Kenneth Nichols, however, struggled to understand both the processes and the scientists they worked with. Suddenly breaking into the new field of nuclear physics, they feel unable to distinguish between technical and personal desires. Although they decided that a site near Knoxville, Tenn., Would be suitable for the first production plant, they had no idea how large the site was and canceled taking it. There are other problems too.
Due to the nature of experimentation, the work of nuclear weapons cannot match the Army's more important duties. The selection of scientist jobs and plant-production construction was often delayed by Marshall's inability to procure critical materials, such as steel, that were also needed in other military production.
Even choosing a name for the AD project was difficult. The name chosen by Jend. Brehon Somerwell, “Substitute Development”, is so imprecise that it seems to reveal too much.
