This sample of red trinitite, forged during the world's first nuclear bomb test, contains a crystal never seen before on Earth. (Image credit: Luca Bindi and Paul J. Steinhardt.)
 

Newly Discovered Quasicrystal – “Magnificent in Its Complexity” – Was Created by the First Nuclear Explosion at Trinity Site

A newly discovered quasicrystal that was created by the first nuclear explosion at Trinity Site, N.M., on July 16, 1945, could someday help scientists better understand illicit nuclear explosions and curb nuclear proliferation.

 In an instant, a metal-coated plutonium device named "Gadget" imploded, creating a gargantuan fireball that rose high into the sky, vaporizing everything it touched. Sand melted into radioactive glass, and a crater nearly as wide as a football field dented the planet. The test — codenamed Trinity — was a success.

But Trinity didn't just destroy; it also left something strange and new behind.

In a study published in the journal Proceedings of the National Academy of Sciences, researchers have detected otherworldly crystals called "quasicrystals" trapped in the bomb-blasted rocks at the Trinity site. These odd gems, which lack the perfect symmetry of true crystals, are usually only seen in meteorites from the early solar system, and are thought to be forged only in the extreme heat and pressure of the universe's most powerful explosions.

These newfound crystals, embedded in the rubble of the Trinity site, provide scientists with proof that quasicrystals can also result from mankind's most explosive creations, according to the study authors. These crystals give nuclear researchers "a new tool in the toolbox" for analyzing the power and impact of past nuclear explosions, both in the U.S. and abroad, study co-author Terry Wallace, director emeritus of Los Alamos National Laboratory in New Mexico, said in a video accompanying the research.

"Understanding another country's nuclear weapons requires that we have a clear understanding of their nuclear testing programs," Wallace said in a statement. "We typically analyze radioactive debris and gases to understand how the weapons were built or what materials they contained, but those signatures decay. A quasicrystal that is formed at the site of a nuclear blast … [will] exist forever."

When the plutonium Gadget detonated on July 16, the resulting fireball was hotter than Earth's sun, Wallace said. The heat and force of this explosion were so strong that the metal test tower and surrounding sand melted together into a new type of glass, later named trinitite.

Most trinitite samples are green, like a pale glass bottle. But rarer samples are red, presumably because they contain greater amounts of copper and other metals from the test tower and recording equipment at the site. In their new study, Wallace and his colleagues examined a red trinitite specimen under an electron microscope, looking specifically at metallic "blobs" that might contain crystals.

In this sample, the team detected a five-sided quasicrystal with an atomic structure never seen on Earth before. The crystal was made predominantly of silicon from the desert sand, but also contained proportionally high amounts of copper, plus some iron and calcium. The crystal is "magnificent in its complexity," Wallace said — and it's still not clear to his team exactly how or why it formed this way.

One thing is clear, though: This quasicrystal has an "unmistakable" origin, based on its composition, radioactivity and discovery location, the researchers said. It's a unique crystal forged in the fires of America's first nuclear blast, and therefore is the oldest human-made quasicrystal on Earth.

Similar crystals could lurk in the rubble of other nuclear test sites — and studying the unique structures of those crystals could reveal important information about the nature of the bombs that created them, Wallace said. Unlocking that knowledge will require a lot more study — and many more crystal samples — but ultimately, it will be worth it to better understand the cosmic-level explosions that humans have learned to unleash here on Earth. 


The above story is based on materials provided by PNAS.

 
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