Researchers working at the Laboratory for Nuclear Science, Massachusetts Institute of Technology (MIT) have built an affordable, pocket-sized muon detector able to sniff out this elementary subatomic particle in the Earth’s atmosphere. According to researchers, this detector costs just $100 to build, and can be easily created using common electrical parts.
A muon is a subatomic particle with properties similar to an electron but being 207 times heavier than an electron. This particle was first discovered in 1936 by Carl Anderson, a scientist at Caltech. Muon is considered a relatively unstable particle as it lasts for just 2.2 microseconds before decaying into an electron and two neutrinos. Muons are found in almost all layers of the Earth’s atmosphere. They are produced when high-energy cosmic rays—emitted by supernovae or other astrophysical events happening beyond our solar system—collide with the Earth’s atmosphere. This collision causes cosmic rays to decay into muons. A small fraction of these muons reaches the air surrounding us—with some going even deeper into the Earth after penetrating its surface.
The MIT team, led by Spencer Axani, a student in MIT’s Department of Physics, originally designed this new muon detector as an add-on to IceCube—the giant particle detector put deep in the South Pole to detect neutrinos. However, MIT researchers soon realized that their device has a great potential to be used as an educational tool for students. Axani then developed new hardware and software components for the device to let it show the exact count of muons passing through it. According to researchers, this detector can be used in almost any environment to detect muons.
“You get funny looks when you take particle detectors into the subway, but we did that in Boston,” Axani says.
“Since the muon rate will decrease the further down you go, we put the detectors in a subway station to measure how far underground we were.”
The team has now set up a CosmicWatch program to educate students about how they can build this device using some easily accessible electrical parts and then use it to track muons in their surroundings. According to MIT researchers, a high school student can easily build this device within four hours in first attempt.
A student group at Boston University is currently planning to send a muon detector to altitudes of around 100,000 feet through a suborbital rocket.
The project was partly funded by the National Science Foundation.
The details regarding the first version of the muon detector were published in the American Journal of Physics.
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