A new handheld muon detector could probe inaccessible buildings.
How do you find out what’s inside a building if you can’t go in? It’s a question that’s surprisingly relevant in areas like disaster relief. In these cases being able to see inside a collapsed structure could mean the difference between life and death.
Seeing the inside
So how exactly do you find out what’s inside a building without going in? By detecting tiny particles called muons. Muons are produced in the upper atmosphere by collisions between air molecules and cosmic rays from the sun and other stars. These muons then make their way down to the ground, where specialised detectors can pick them up.
Muons can usually pass through walls, but sometimes they collide instead. This means a detector will see fewer muons if there are walls or other objects in the way. By measuring how many muons pass through a certain area—like a building—we can figure out exactly how much of that area is solid and how much is empty space.
It’s a technique that’s being used right now to map the debris inside the collapsed reactors at the Fukushima nuclear plant in Japan. It was also recently used to discover a previously unknown chamber in the Great Pyramid of Giza. But there’s one problem: existing muon detectors are large and expensive, which is why a group of physicists at MIT are building a cheaper, portable version.
The handheld muon detector
The detector was built by researchers from MIT’s Laboratory for Nuclear Science. It costs around R1 400 and can be assembled in an afternoon. Currently, MIT is marketing the detector as a learning experience for high school and college students, and its website provides detailed instructions on how to build and operate the device.
This design could be used by researchers looking to probe inaccessible buildings or study ancient monuments. The lower cost means that more teams could have access to this technology. The smaller size means it will be easier to setup and record muon data. Maybe someday, thanks to this research, every first responder will have access to a cheap, handheld muon detector.