Manhattan+Project

The Atomic Bomb

Manhatten Project Study Guide

__**The Manhattan Project**__ The Manhattan Project was one of the best kept secrets of World War II. Einstein sent President Roosevelt a letter about developing a nuclear weapon, and three years later, the first controlled nuclear reaction was performed by **Enrico Fermi**, in his reactor, called CP-1, underneath a squash court at the University of Chicago. On July 6, 1945, the first atomic bomb exploded in Los Alamos. After witnissing the explosion, **J. Robert Oppenheimer**, the lead of the project, quoted a line from the Hindu scripture. He said " Now, I am become Death, the destroyer of worlds". The Manhattan Project produced three bombs: the first bomb was known as "Gadget" and was used as a test model. Due to the enormous expense and slow production rates for explosive material, no further tests were conducted. The Project eventually used two bombs, the same two that were dropped on Hiroshima and Nagasaki. One was a Gun-Triggered Fission Bomb, also known as **Little Boy**, dropped on Hiroshima, which fired a small shell of uranium at the rest of the material, which started the reaction. The other was an Implosion-Triggered Fission Bomb, a.k.a. **Fat Man**, dropped on Nagasaki, which uses a contained explosion to start the nuclear material's explosion. Both types had problems, but they were solved by the team before the use of the bombs. For example, in the Implosion-Triggered Fission Bomb, it was unknown how to direct the shock wave caused by the first explosion uniformly across the entire nuclear mass. The history of the Manhattan Project remained classified for many years. It was so secret that Harry S. Truman, although vice president of the United States, was not made aware of its existence until after the death of Roosevelt in 1945.



[|How Atomic Bombs Work] [|USA Nuclear Weapon History] [|Manhattan Project Rediscovered Video]

