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Trinity Test

A resource guide created for the 75th anniversary of the Trinity Test near Alamogordo, New Mexico, on July 16, 1945. LA-UR-20-25085.
July 16, 1945:
On this day [...] the US detonated the world's first nuclear weapon, a plutonium-based device, near Alamogordo, New Mexico. Trinity, as the test was known, was successful. Three weeks later, a second successful detonation took place -- over the Japanese city of Hiroshima.
From: Trinity Test. (2015). Physics Today, Physics Today, 2015. DOI: 10.1063/PT.5.031009
 
All photos on this page are courtesy of the National Security Research Center (NSRC).
 
For even more information on the Trinity Test, including a video on the science of Trinity, see LANL's Trinity 75th anniversary webpage.

Trinity Test In Numbers

The exact time and date of the Trinity Test and the detonation of the Gadget test bomb was 5:29:45 July 16, 1945 (from an external LANL article The Trinity Test).

The power from the Gadget’s detonation was equivalent to around 21,000 tons of TNT and its mushroom cloud grew to about 3,280 feet wide, then rose in a column of smoke higher than 40,000 feet (from an internal LANL article).

Notable Trinity Scientists

According to Kenneth Bainbridge's Trinity report, a number of notable scientists took part in the Trinity Test, including:

  • Harold Agnew
  • Luis Alvarez
  • Norris Bradbury
  • Enrico Fermi
  • J. Robert Oppenheimer
  • Emilio Segre
  • Victor Weisskopf

Getting Ready For Trinity

A detailed map of the Trinity Site in New Mexico.

A detailed map of the Trinity Site in New Mexico.

Norris Bradbury sitting atop the Trinity Tower, head resting on hand.

Norris Bradbury sitting atop the Trinity Tower.

A man taking measurements from a wood platform.

Taking measurements during testing.

A device used for the test with a crane dangling overhead.

A device used for the test with a crane dangling overhead.

A group of men pose in front of a transporation vehicle carrying the Gadget.

A group of men pose in front of a transporation vehicle carrying the Gadget.

A group of men, overseen by Oppenheimer, performing the final assembly of the Gadget.

A group of men, overseen by Director Oppenheimer, performing the final assembly of the Gadget.

Trinity Test In Images

A black and white image of the beginning of the Trinity test detonation.
An image of the detonation cloud with the caption,
An image of the detonation cloud with the caption,
An image of the detonation cloud pointing out that the shock wave is faint, the flame front is no longer sharp, the belt is still cooling, the skirt of dust is still quite hot, and the various hot spots on the cloud.
An image of the detonation cloud with the caption,
An image of the detonation cloud with the caption,
A clear black and white shot of the mushroom cloud from the Trinity detonation.

Trinity's Legacy

Additional Resources

These items are available through the LANL Research Library. You can also use services such as WorldCat to check if another library near you has a physical or electronic copy of any of the materials on this guide.

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