Muons, the new x-ray

Want to know if a volcano will explode? How about if a hidden chamber lurks in The Great Pyramid? What if someone is smuggling nuclear material in their cargo?

“Muons” are now being used to answer all these questions.

Cosmic rays collide with the upper atmosphere producing a rain of subatomic particles called muons. When muons pass through dense matter, they scatter. The resulting ‘shadow’ from this scattering can be observed in a similar way that a skeleton casts a shadow on an x-ray film. Muons however are much more penetrative, allowing engineers and scientists to detect voids in difficult to reach places.

In 2017, an international team of scientists discovered a large void above The Great Pyramid of Giza’s Grand Gallery, a possible second Grand Gallery, by detecting muons in the lower chambers using solar cell like panels plastered on the ceiling. The archaeological discovery was huge and impossible to make with any other non-destructive technique. The event was a win for both archaeology and applied particle physics.

Since this demonstration, muography – the practice of detecting muons to create images – has been applied to several new fields. Researchers in Japan have recently been developing the technique to detect lava flows which might one day be used to predict volcanic eruptions, and nuclear engineers are making muon detectors to sense fragments of uranium through solid concrete or steel.

Muon detection has potentially powerful applications across many fields of research and industry, so expect more amazing and innovative uses for these tiny particles.

Read more: Nature / Nature (2) / Scientific American / Science

Image: YouTube – Los Alamos National Lab

This story is taken from the 01 June 2018 edition of The Warren Centre’s Prototype newsletter. Sign up for the Prototype here.