The Manhattan Project

By: Chris Cruz

Starting the project

It started when German Physicist Albert Einstein sent a letter to US president Franklin D. Roosevelt warning him that uranium could be made into “extremely powerful bombs of a new type”. Over the next 18 months the president’s advisory committee researched the separation of the rare uranium-235. On June 15, 1940, Roosevelt created the National Defense Research Committee, whose chairman, Vannevar Bush, received responsibility over the Uranium Committee.Bush decided that a bold atomic strike was needed. After a meeting with Bush on Oct. 9, 1941, Roosevelt ordered that work on the bomb be "expedited … in every way possible." Determined to keep the project as secret as possible, Roosevelt, with Harold Smith, paid for the project, which cost about $1.9 billion (in 1944 dollars; about $23.6 billion in 2000 dollars).

Creating the atomic bomb

Three months after the US entered World War II, Bush recommended to the president that the United States Army be put in charge of constructing plants to produce enough fissionable materials. Responsibility was given to Army Corps of Engineers, which made the Manhattan Engineer District. A group led by Enrico Fermi built the first nuclear reactor. It was made up of a pile of uranium bricks embedded in uranium metal slugs. On Dec. 2, 1942 plutonium was produced at a constant rate. The government decidedto go ahead with construction of the nuclear facilities. ACE began making a pilot plant using the electromagnetic-separation technique in Oak Ridge, Tennessee. The plant made uranium in explosive quantities by 1945. The efforts to design the atomic bomb were spread among a number of universities. The project movedthe work to Los Alamos, New Mexico. J. Robert Oppenheimer was hired as director of the new laboratory.Oppenheimer began work at Los Alamos in March 1943, scientists and equipment from many universities moved to the laboratory. The work in the new lab included calculations of how fissionable material might be made to explodeand the construction and testing of the devices. Roosevelt was told that the first bombs would be ready to use against Japan in August 1945 and the probability for success was at least 99%.

Exploding the first Atomic bomb

The first atomic bomb was exploded at 5:30 AM on July 16, 1945 at a site called Trinity 120 miles south of Albuquerque, NM. It was detonated on top of a steel tower surrounded by scientific equipment, with remote monitoring taking place in bunkers. The explosion came as a bright light flash, a sudden heat wave, and later a huge roar as the shock wave passed. The bomb made an explosive power equivalent to 20,000 tons of TNT; the tower was completely vaporized and the surrounding desert surface fused to glass. The following month, two other atomic bombs produced by the project, the first using uranium and the second using plutonium, were dropped on Hiroshima and Nagasaki, Japan

Little Boy - Atom Bomb - Hiroshima



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