Mahatten Project Essay Research Paper Manhattan Project

Mahatten Project Essay, Research Paper

Manhattan Project and the A-Bomb

Just before the beginning of World War II, Albert Einstein

wrote a letter to President Franklin D. Roosevelt. Urged by

Hungarian-born physicists Leo Szilard, Eugene Wingner, and Edward

Teller, Einstein told Roosevelt about Nazi German efforts to purify

Uranium-235 which might be used to build an atomic bomb. Shortly after

that the United States Government began work on the Manhattan Project.

The Manhattan Project was the code name for the United States effort

to develop the atomic bomb before the Germans did. “The first

successful experiments in splitting a uranium atom had been carried

out in the autumn of 1938 at the Kaiser Wilhelm Institute in

Berlin”(Groueff 9) just after Einstein wrote his letter. So the race

was on. Major General Wilhelm D. Styer called the Manhattan Project

“the most important job in the war . . . an all-out effort to build an

atomic bomb.”(Groueff 5) It turned out to be the biggest development

in warfare and science’s biggest development this century. The most

complicated issue to be addressed by the scientists working on the

Manhattan Project was “the production of ample amounts of ‘enriched’

uranium to sustain a chain reaction.”(Outlaw 2) At the time,

Uranium-235 was hard to extract. Of the Uranium ore mined, only about

1/500 th of it ended up as Uranium metal. Of the Uranium metal, “the

fissionable isotope of Uranium (Uranium- 235) is relatively rare,

occurring in Uranium at a ratio of 1 to 139.”(Szasz 15) Separating the

one part Uranium-235 from the 139 parts Uranium-238 proved to be a

challenge. “No ordinary chemical extraction could separate the two

isotopes. Only mechanical methods could effectively separate U-235

from U-238.”(2) Scientists at Columbia University solved this

difficult problem. A “massive enrichment laboratory/plant”(Outlaw 2)

was built at Oak Ridge, Tennessee. H. C. Urey, his associates, and

colleagues at Columbia University designed a system that “worked on

the principle of gaseous diffusion.”(2) After this process was

completed, “Ernest O. Lawrence (inventor of the Cyclotron) at the

University of California in Berkeley implemented a process involving

magnetic separation of the two isotopes.”(2) Finally, a gas centrifuge

was used to further separate the Uranium-235 from the Uranium-238. The

Uranium-238 is forced to the bottom because it had more mass than the

Uranium-235. “In this manner uranium-235 was enriched from its normal

0.7% to weapons grade of more than 90%.”(Grolier 5) This Uranium was

then transported to “the Los Alamos, N. Mex., laboratory headed by J.

Robert Oppenheimer.”(Grolier 5) “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.”(Outlaw 3) Once the purified Uranium reached New

Mexico, it was made into the components of a gun-type atomic weapon.

“Two pieces of U-235, individually not large enough to sustain a chain

reaction, were brought together rapidly in a gun barrel to form a

supercritical mass that exploded instantaneously.”(Grolier 5) “It was

originally nicknamed ‘Thin Man’(after Roosevelt, but later renamed

‘Little Boy’ (for nobody) when technical changes shortened the

proposed gun barrel.”(Szasz 25) The scientists were so confident that

the gun-type atomic bomb would work “no test was conducted, and it was

first employed in military action over Hiroshima, Japan, on Aug. 6,

1945.”(Grolier 5) Before the Uranium-235 “Little Boy” bomb had been

developed to the “point of seeming assured of success,”(Grolier 5)

another bomb was proposed. The Uranium-238 that had been earlier ruled

out as an option was being looked at. It could capture a free neutron

without fissioning and become Uranium-239. “But the Uranium-239 thus

produced is unstable (radioactive) and decays first to neptunium-239

and then to plutonium-239.”(Grolier 5) This proved to be useful

because the newly created plutonium-239 is fissionable and it can “be

separated from uranium by chemical techniques,”(6) which would be far

simpler than the physical processes to separate the Uranium-235 from

the Uranium-238. Once again the University of Chicago, under Enrico

Fermi’s direction built the first reactor. “This led to the

construction of five large reactors at Hanford, Wash., where U-238 was

irradiated with neutrons and transmuted into plutonium.”(6) The

plutonium was sent to Los Alamos. The problem to overcome in the

development of the plutonium bomb was an isotope of plutonium. The

scientists feared this isotope would cause premature detonation and

most of the plutonium would blow apart before it could al

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