Trinity (nuclear test)

Trinity
Mushroom cloud seconds after detonation of the Gadget
Information
Country	United States
Test site	Trinity Site, New Mexico
Date	July 16, 1945 (79 years ago) (1945-07-16)
Test type	Atmospheric
Device type	Plutonium implosion fission
Yield	25 kt (100 TJ)
Test chronology
Operation Crossroads →

Trinity Site
U.S. National Register of Historic Places
U.S. Historic district
U.S. National Historic Landmark District
NM State Register of Cultural Properties
Trinity Site obelisk
Show map of New Mexico Show map of the United States
Nearest city	Bingham, New Mexico
Coordinates	33°40′38″N 106°28′31″W / 33.67722°N 106.47528°W / 33.67722; -106.47528
Area	36,480 acres (14,760 ha)
Built	1945 (1945)
NRHP reference No.	66000493[1]
NMSRCP No.	30
Significant dates
Date of Nuclear Explosion	July 16, 1945
Added to NRHP	October 15, 1966
Designated NHLD	December 21, 1965[2]
Designated NMSRCP	December 20, 1968

Trinity was the code name of the first detonation of a nuclear weapon, conducted by the United States Army at 5:29 a.m. MWT^[a] (11:29:21 GMT) on July 16, 1945, as part of the Manhattan Project. The test was of an implosion-design plutonium bomb, nicknamed "The Gadget", of the same design as the Fat Man bomb later detonated over Nagasaki, Japan, on August 9, 1945. Concerns about whether the complex Fat Man design would work led to a decision to conduct the first nuclear test. The code name "Trinity" was assigned by J. Robert Oppenheimer, the director of the Los Alamos Laboratory, possibly inspired by the poetry of John Donne.

The test, both planned and directed by Kenneth Bainbridge, was conducted in the Jornada del Muerto desert about 35 miles (56 km) southeast of Socorro, New Mexico, on what was the Alamogordo Bombing and Gunnery Range (renamed the White Sands Proving Ground just before the test). The only structures originally in the immediate vicinity were the McDonald Ranch House and its ancillary buildings, which scientists used as a laboratory for testing bomb components. Fears of a fizzle prompted construction of "Jumbo", a steel containment vessel that could contain the plutonium, allowing it to be recovered; but ultimately Jumbo was not used in the test. On May 7, 1945, a rehearsal was conducted, during which 108 short tons (98 t) of high explosive spiked with radioactive isotopes was detonated.

Some 425 people were present on the weekend of the Trinity test. Observers included Vannevar Bush, James Chadwick, James B. Conant, Thomas Farrell, Enrico Fermi, Hans Bethe, Richard Feynman, Isidor Isaac Rabi, Leslie Groves, Robert Oppenheimer, Frank Oppenheimer, Geoffrey Taylor, Richard Tolman, Edward Teller, and John von Neumann. The Trinity bomb released the explosive energy of 25 kilotons of TNT (100 TJ) ± 2 kilotons of TNT (8.4 TJ), and a large cloud of fallout. Thousands of people lived closer to the test than would have been allowed under guidelines adopted for subsequent tests, but no one living near the test was evacuated before or afterward.

The test site was declared a National Historic Landmark district in 1965 and listed on the National Register of Historic Places the following year.

Cite error: There are <ref group=lower-alpha> tags or {{efn}} templates on this page, but the references will not show without a {{reflist|group=lower-alpha}} template or {{notelist}} template (see the help page).