The Manhattan Project

The Manhattan Project

The Manhattan Project was the code name of the America’s attempt to construct an atomic bomb during World War II. It was named after the Manhattan Engineer District of the U.S. Army Corps of Engineers, because a lot of it’s earlier research was done in New York City. An atomic bomb is a weapon that uses the energy from a nuclear reaction called Fission for its destruction.

The idea that mass could be changed into energy was predicted by Albert Einstein in the earlier part of the 1900’s. John D. Cockcroft and Ernest Walton confirmed this by experiments in 1932. Then in 1938, nuclear fission was discovered by German scientists, and it was feared by many of the U.S. scientists, that Hitler would try to build a fission bomb. Three Hungarian-born physicists, Leo Szilard, Eugene Wigner, and Edward Teller asked Albert Einstein to send a letter to Franklin Roosevelt. Compelled by the letter in late 1939, Roosevelt ordered an effort to obtain an atomic weapon before Germany.

At first, this program was led by Vannevar Bush, head of the National Defense Research committee and the Office of Scientific Research and Development. Then it came under control of Leslie Groves of the Army Corps of Engineers. Groves quickly bought a site in Oak Ridge, Tennessee, as a place for processing the Uranium-235 from the more common Uranium-238. Uranium-235 is used because it is fissionable, it releases many neutrons, and does not capture many. However, 99.3% of uranium in nature is the U-238 isotope, and only .7% is the lighter, more “fissionable” isotope U-235. Next, he gathered and combined research from many East Coast universities under direction of Arthur Compton, at the University of Chicago. He appointed theoretical physicist, J. Robert Oppenheimer as the director of the weapons laboratory, which was built on an isolated mesa located at Los Alamos, New Mexico.

After much work, a porous barrier that could separate the isotopes of uranium was made, and it was installed in the Oak ridge gaseous diffusion plant. In 1945, uranium-235, pure enough for use in a bomb was produce and sent to Los Alamos, where it was made into a gun-type weapon. One small piece of Uranium-235, which was not big enough to hold a chain reaction itself, was fired at another small piece. This was done by means of a explosive charge, inside a cylinder shaped tube, which for...

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...he U.S. built thousands of atomic bombs, and different types of smaller of fission weapons. A much more powerful bomb, the Hydrogen Bomb, became the leader of the U.S. nuclear arsenal.

In general, the Hydrogen Bomb was like an atomic bomb with a Hydrogen fuel. The fuel would fusion (opposite of fission) from the bomb’s fission explosion, which would further strengthen the original fission, causing a much larger chain reaction. The United States was the only nation that had atomic weapons in 1945. Then in 1949, the USSR learned how to make them. Great Britain followed in 1952, France in 1960, the People’s Republic of China in 1964, and India (it was claimed that they were for

peaceful purposes only) in 1974. In 1968, the Nuclear Non-Proliferation Treaty which was signed by the U.S., the USSR, and Britain. It set up precise requirements for any “non-nuclear” nations that want to build nuclear energy industries.

However, several other countries are believed to have some nuclear weapons, like Israel and South Africa. North Korea, Iran , and Pakistan may be on the verge of nuclear discovery. When the Soviet Union broke up it added to risks of the spreading of nuclear power.