Project Trinity 1945-1946 | Page 6

guard against the blast and
radiation produced.
1.1 HISTORICAL BACKGROUND OF PROJECT TRINITY
The development of a nuclear weapon was a low priority for the United
States before the outbreak of World War II. However, scientists exiled
from Germany had expressed concern that the Germans were
developing a nuclear weapon. Confirming these fears, in 1939 the
Germans stopped all sales of uranium ore from the mines of occupied
Czechoslovakia. In a letter sponsored by group of concerned scientists,
Albert Einstein informed President Roosevelt that German experiments
had shown that an induced nuclear chain reaction was possible and
could be used to construct extremely powerful bombs (7; 12)*.
* All sources cited in the text are listed alphabetically in the reference
list at the end of this volume. The number given in the text corresponds
to the number of the source document in the reference list.
In response to the potential threat of a German nuclear weapon, the

United States sought a source of uranium to use in determining the
feasibility of a nuclear chain reaction. After Germany occupied
Belgium in May 1940, the Belgians turned over uranium ore from their
holdings in the Belgian Congo to the United States. Then, in March
1941, the element plutonium was isolated, and the plutonium-239
isotope was found to fission as readily as the scarce uranium isotope,
uranium-235. The plutonium, produced in a uranium-fueled nuclear
reactor, provided the United States with an additional source of
material for nuclear weapons (7; 12).
In the summer of 1941, the British Government published a report
written by the Committee for Military Application of Uranium
Detonation (MAUD). This report stated that a nuclear weapon was
possible and concluded that its construction should begin immediately.
The MAUD report, and to a lesser degree the discovery of plutonium,
encouraged American leaders to think more seriously about developing
a nuclear weapon. On 6 December 1941, President Roosevelt appointed
the S-1 Committee to determine if the United States could construct a
nuclear weapon. Six months later, the S-1 Committee gave the
President its report, recommending a fast-paced program that would
cost up to $100 million and that might produce the weapon by July
1944 (12).
The President accepted the S-1 Committee's recommendations. The
effort to construct the weapon was turned over to the War Department,
which assigned the task to the Army Corps of Engineers. In September
1942, the Corps of Engineers established the Manhattan Engineer
District to oversee the development of a nuclear weapon. This effort
was code-named the "Manhattan Project" (12).
Within the next two years, the MED built laboratories and production
plants throughout the United States. The three principal centers of the
Manhattan Project were the Hanford, Washington, Plutonium
Production Plant; the Oak Ridge, Tennessee, U-235 Production Plant;
and the Los Alamos Scientific Laboratory in northern New Mexico. At
LASL, Manhattan Project scientists and technicians, directed by Dr. J.
Robert Oppenheimer,* investigated the theoretical problems that had to

be solved before a nuclear weapon could be developed (12).
* This report identifies by name only those LASL and MED personnel
who are well-known historical figures.
During the first two years of the Manhattan Project, work proceeded at
a slow but steady pace. Significant technical problems had to be solved,
and difficulties in the production of plutonium, particularly the inability
to process large amounts, often frustrated the scientists. Nonetheless,
by 1944 sufficient progress had been made to persuade the scientists
that their efforts might succeed. A test of the plutonium implosion
device was necessary to determine if it would work and what its effects
would be. In addition, the scientists were concerned about the possible
effects if the conventional explosives in a nuclear device, particularly
the more complex implosion-type device, failed to trigger the nuclear
reaction when detonated over enemy territory. Not only would the
psychological impact of the weapon be lost, but the enemy might
recover large amounts of fissionable material.
In March 1944, planning began to test-fire a plutonium-fueled
implosion device. At LASL, an organization designated the X-2 Group
was formed within the Explosives Division. Its duties were "to make
preparations for a field test in which blast, earth shock, neutron and
gamma radiation would be studied and complete photographic records
made of the explosion and any atmospheric phenomena connected with
the explosion" (13). Dr. Oppenheimer chose the name TRINITY for the
project in September 1944 (12).
1.2 THE PROJECT TRINITY SITE
The TRINITY site was chosen by Manhattan Project scientists after
thorough study of eight different sites. The site selected was an area
measuring 29 by 39 kilometers* in the northwest corner of the
Alamogordo Bombing Range. The Alamogordo Bombing Range was
located in a desert in south-central New Mexico called the Jornada del
Muerto ("Journey of Death"). Figure 1-1 shows the location of the
bombing range. The site