The Manhattan Project Essay, Research Paper

Manhattan Project

The Einstein Letter

Leo Szilard, like many other foreign-born physicists in the U.S. who had fled fascism, knew Germany was conducting nuclear research. Having learned the Germans had banned the export of uranium, he believed the Germans were developing an atomic bomb. Fearing what would happen if Germany developed a nuclear weapon, he urged Dr. Albert Einstein to convince the American government to support nuclear research.

On August 2, 1939, a month before Germany invaded Poland, Einstein wrote a letter to President Roosevelt, recommending that the U.S. fund nuclear research, stating that it could result in “extremely powerful bombs” made of uranium. Einstein’s recommendation was based on the research of physicists Leo Szilard and Enrico Fermi. Szilard had developed the theory of nuclear fission. But it was Fermi who was the first to actually produce nuclear fission in the laboratory, which won him the 1938 Nobel Prize for Physics.

Based on Einstein’s letter, President Roosevelt authorized a study, but the decision to devote full energy to the production of the bomb was not made until December 6, 1941: the day before the Japanese attack on Pearl Harbor.

General Leslie Groves

General Groves was chosen to make the atomic bomb a reality, code named the Manhattan Project. He named J. Robert Oppenheimer, a brilliant nuclear physicist from the University of California at Berkeley as director. Together they chose Los Alamos, New Mexico, a remote location not far from Santa Fe, as the site for the design and construction of atomic bombs. Oppenheimer gathered scientists, many of them Nobel Prize winners, from the most prestigious universities in the U.S.: University of California at Berkeley, University of Chicago, Columbia University, as well as several British and Canadian scientists.

The U.S. Army Corps of Engineers built power stations, factories, foundries, blast furnaces, steel works, hospitals, laboratories and housing at Los Alamos. It involved over 200,000 people and cost the U.S. two billion dollars. The Manhattan Project was a collaboration of American science and industry carried out under the direction of the U.S. Army. The Manhattan Project was conducted in complete secrecy not only from the enemy but from the American public. Most of the factory workers were unaware of what they were producing.

Manhattan Project Support Facilities

As part of the Manhattan project, two different facilities were built to produce weapon-grade uranium and plutonium. The Manhattan Project was building two different types of atomic bombs, a uranium bomb and a plutonium bomb, because uranium was difficult to produce in quantities needed. Plutonium, an artificially manufactured element derived from uranium, could be produced in sufficient quantity but it needed a different kind of bomb detonation device.

Uranium Production: Oak Ridge, Tennessee

A huge gas diffusion plant was built to produce weapon-grade uranium. An extremely corrosive uranium hexafluoride gas was pumped through barriers that had millions of tiny holes. The lighter molecules containing the needed uranium-235 were diffused faster than the heavier uranium-238 molecules. After the gas had been cycled through thousands of barriers it was “enriched” to a high concentration, 90 percent, of pure uranium-235.

Plutonium Production: Hanford, Washington

Nuclear reactors were built to provide the neutrons to produce plutonium from uranium. When the plentiful uranium-238 isotope is bombarded with neutrons, it changes into a new element. This new element changes into plutonium-239. Plutonium-239, like uranium-235, undergoes fission and can be used as bomb material. Producing plutonium-239 in large quantities requires an intense source of neutrons.

Trinity Test Site, Alamogordo, New Mexico

The first atomic bomb tested at Trinity on July 16, 1945 proved that the U.S. was in possession of the most destructive weapon ever devised by man. The bomb was powered by the splitting of all the nuclei in several kilograms of plutonium. A sphere of plutonium the size of a baseball produced an explosion equal to 15,000 to 20,000 tons of TNT. When the bomb exploded at Trinity at 5:30 a.m., it vaporized the tower and turned asphalt around the base of the tower to green sand. Suddenly the sky was brighter than several suns. Seconds after the explosion came a huge blast that sent withering heat across the desert.

A massive orange and yellow cloud in the shape of a mushroom surged and billowed upward reaching into the sub-stratosphere up to an elevation of 41,000 feet. A soldier 10,000 feet away was knocked off his feet by the force of the shock wave. The flash of light was seen more than ten miles away, and a soldier five miles away was temporarily blinded. The explosion was heard 50 miles away.

Russian Spy at Los Alamos

A German refugee working on the British team of scientists at Los Alamos, Klaus Fuchs, was a Soviet spy. He and other spies passed information about American nuclear research to the Soviets from 1942 to 1949. This could explain Stalin’s indifferent reaction when Truman told him at the Potsdam Conference that the U.S. had a new weapon. Fuchs was caught and convicted of espionage, and sentenced to 15 years in prison for disclosing nuclear secrets. After his release, he went to East Germany to work in their nuclear research center.