Russia: Scientists from three major Russian research institutes have made an important breakthrough in the field of muon tomography, by creating tracking devices that will allow geologists to ‘see through’ objects up to thousands of meters in diameter below the earth’s surface.
Researchers from Russia‘s National University of Science and Technology, the Russian Academy of Sciences’ Institute of Physics, and Moscow State University’s Institute of Nuclear Physics have joined their efforts to create a special tracking device which allows geologists to create accurate 3D maps of the environment deep beneath the planet’s surface.
The trackers use a form of muon tomography, the technique using cosmic ray-generated muon particles, to radiograph underground objects and geological structures.
Clarifying how muon tomography works, RIA Novosti explained that as cosmic ray-generated particles find their way into the earth’s atmosphere (40 km and below), they collide with molecules which make up the atmosphere.
This creates new particles, some of which quickly become muons – unstable subatomic particles with a mean lifetime considerably longer than many other subatomic particles. Able to pass through earth’s entire atmosphere in the space of their ‘lifetime’, muons are also able to penetrate up to 8,500 meters below the water, or 2,000 meters into the earth’s surface.
The denser the matter, the faster the muon particles’ presence wanes. With the help of muon tracking detectors, solid objects can be observed to track the passage of muons through its cavities. Three detectors placed around an object are usually sufficient to create a three dimensional map.
Muons are detected with the help of a series of photographic plates layered with silver bromide, used to reveal and match the illuminated areas, building a trajectory of the exposure. The smaller the bromide granules and the more accurate the matching algorithms, the more correct the 3D picture of the object.
Experiments to confirm the workability of the new muon tracking technology have been held in a mine belonging to the Geological Service of the Russian Academy of Sciences in Obninsk, western Russia.