THE GADGET Nicknamed “The Gadget” lest spies discover information referring to it as a bomb, the device was assembled on the top of a 100-foot tower and had an implosion-type design. This is how it worked: Sphere with plutonium core
The bomb’s core, a sphere of plutonium in the center of a sphere of uranium, is surrounded by explosive charges and detonators.
Plutonium core compressed
Uranium
High-explosive blocks
Time after the explosion +4 hour +3 hours +2 hours
THE TEST SITE After considering locations in California, Texas and Colorado, the Army chose an isolated section of the White Sands Proving Ground in New Mexico.
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Detonating the explosives simultaneously causes the plutonium to be dramatically compressed, increasing its density and initiating an uncontrolled nuclear Explosions reaction.
+1 hour >5 R/hr Radiation levels diminish over time
380
UTAH
0
100
MILES
ARIZ. Los Alamos
COLORADO
Santa Fe
White Sands Proving Ground
Albuquerque
Fallout At ground zero, the radiation was upward of 75 roentgens for the first hour. Over time, the cloud of particles at the Trinity test site dissipated and lost most of its radioactive properties.
Fireball radius
North shelter
300 feet 1.5 miles
Trinity site White Sands Proving Ground
El Paso MEXICO
TEXAS
Ground zero
West shelter South shelter
s ain unt Mo ura Osc
NEW MEXICO
Thermal radiation radius
Shelters
10 miles
All situated in a radius of five miles from ground zero.
20 miles
Explosion The explosion took place at 5:29 a.m. The heat of the blast was 10,000 times greater than is found on the surface of the sun, and the light was so intense that it could be seen from 180 miles away.
Trinitite The explosion left a green, glassy residue on the desert floor. The sand reached temperatures above 2,678 degrees and melted.
Primary blast wave front
THE FIRST 10 SECONDS
According to the official evaluation of the test, Trinity delivered a yield of about 19 kilotons of TNT. The explosion was so powerful that in 10 seconds its blast wave front traveled more than two miles.
Reflected blast wave front
Hot gaseous residue and radiation Fireball
Primary blast wave front
Reflected blast wave front Wind speed: 180 mph
Mach front
Wind speed: 40 mph
Afterwinds
1 second
3 seconds
10 seconds
Trinity created an intensely hot and bright fireball that emitted thermal radiation capable of causing skin burns and igniting flammable material at a considerable distance. After the explosion, a destructive shock wave moved rapidly away from the fireball.
The primary blast wave struck the ground, creating another blast wave by reflection. The two fused to form a single wave called a Mach front.
Trinity’s fireball diminished in brightness, but it was still very hot and rising at a rapid rate, causing air to be drawn inward and upward, somewhat similar to the updraft of a chimney. This produced strong air currents, called afterwinds, that raised dirt and debris from the surface, forming the stem of what would become known as a mushroom cloud. The particles of the cloud, which were highly radioactive, were eventually dispersed by the wind.
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miles
THE WASHINGTON POST