On August 2nd 1939, just before the beginning of World War II, Albert Einstein wrote to then President Franklin D. Roosevelt. Einstein and several other scientists told Roosevelt of efforts in Nazi Germany to purify U-235 with which might in turn be used to build an atomic bomb. It was shortly thereafter that the United States Government began the serious undertaking known only then as the Manhattan Project. Simply put, the Manhattan Project was committed to expedient research and production that would produce a viable atomic bomb.
The most complicated issue to be addressed was the production of ample amounts of ‘enriched’ uranium to sustain a chain reaction. At the time, Uranium-235 was very hard to extract. In fact, the ratio of conversion from Uranium ore to Uranium metal is 500:1. An additional drawback is that the 1 part of Uranium that is finally refined from the ore consists of over 99% Uranium-238, which is practically useless for an atomic bomb. To make it even more difficult, U-235 and U-238 are precisely similar in their chemical makeup. This proved to be as much of a challenge as separating a solution of sucrose from a solution of glucose.
No ordinary chemical extraction could separate the two isotopes. Only mechanical methods could effectively separate U-235 from U-238. Several scientists at Columbia University managed to solve this dilemma. A massive enrichment laboratory/plant was constructed at Oak Ridge, Tennessee. H.C.
Urey, along with his associates and colleagues at Columbia University, devised a system that worked on the principle of gaseous diffusion. Following this process, Ernest O. Lawrence (inventor of the Cyclotron) at the University of California in Berkeley implemented a process involving magnetic separation of the two isotopes. Following the first two processes, a gas centrifuge was used to further separate the lighter U-235 from the heavier non-fissionable U-238 by their mass. Once all of these procedures had been completed, all that needed to be done was to put to the test the entire concept behind atomic fission. For more information on these procedures of refining Uranium, see Section 3.
Over the course of six years, ranging from 1939 to 1945, more than 2 billion dollars were spent on the Manhattan Project. The formulas for refining Uranium and putting together a working bomb were created and seen to their logical ends by some of the greatest minds of our time. Among these people who unleashed the power of the atomic bomb was J. Robert Oppenheimer. Oppenheimer was the major force behind the Manhattan Project. He literally ran the show and saw to it that all of the great minds working on this project made their brainstorms work.
He oversaw the entire project from its conception to its completion. Finally the day came when all at Los Alamos would find out whether or not The Gadget (code-named as such during its development) was either going to be the colossal dud .