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 was chosen for its remote location and good weather
and because it was already owned by the Government. MED obtained
permission to use the site from the Commanding General of the Second
Air Force (Army Air Forces) on 7 September 1944 (12). Figure 1-2
shows the TRINITY site with its major installations.

* Throughout this report, surface distances are given in metric units.
The metric conversion factors include