Trinity Site: 1945-1995.
Page: 4

Project in June 1942. The project was given overall responsibility of
designing and building an atomic bomb. At the time it was a race to
beat the Germans who, according to intelligence reports, were building
their own atomic bomb.

Under the Manhattan Project three large facilities were constructed.
At Oak Ridge, Tenn., huge gas diffusion and electromagnetic process
plants were built to separate uranium 235 from its more common form,
uranium 238. Hanford, Wash. became the home for nuclear reactors
which produced a new element called plutonium. Both uranium 235 and
plutonium are fissionable and can be used to produce an atomic
explosion.

Los Alamos was established in northern New Mexico to design and build
the bomb. At Los Alamos many of the greatest scientific minds of the
day labored over the theory and actual construction of the device.
The group was led by Dr. J. Robert Oppenheimer who is credited with
being the driving force behind building a workable bomb by the end of
the war.



The Theory


Los Alamos scientists devised two designs for an atomic bomb--one
using the uranium and another using the plutonium. The uranium bomb
was a simple design and scientists were confident it would work
without testing. The plutonium bomb worked by compressing the
plutonium into a critical mass which sustains a chain reaction. The
compression of the plutonium ball was to be accomplished by
surrounding it with lens-shaped charges of conventional explosives.
They were designed to all explode at the same instant. The force is
directed inward, thus smashing the plutonium from all sides.

In an atomic explosion, a chain reaction picks up speed as atoms
split, releasing neutrons plus great amounts of energy. The escaping
neutrons strike and split more atoms, thus releasing still more
neutrons and energy. In a nuclear explosion this all occurs in a
millionth of a second with billions of atoms being split.

Project leaders decided a test of the plutonium bomb was essential
before it could be used as a weapon of war. From a list of eight
sites in California, Texas, New Mexico and Colorado, Trinity Site was