Electron Antineutrinos Detected

Scientists involved in the Borexino experiment managed to recently identify the first traces of geo-neutrinos in their detector, a facility buried under 1.5 kilometers of mountain. Located in Italy, underneath the Gran Sasso mountain, near l'Aquila, the 80-scientist endeavor managed to identify tell-tale signs of electron antineutrinos, which the group believes were formed via the radioactive decay processes going on inside our planet's mantle and crust, PhysOrg reports.

Neutrinos can be best described as very small, very inert, almost-massless elementary particles, with zero electric charge. They originate within the Sun, but can also be produced by cosmic rays slamming into Earth. Analyzing them has been an ongoing effort, mostly because they tend to pass through regular matter as if it wasn't there. These particles can pass through the Earth without as much experiencing the slightest speed variation, and so detecting them is incredibly difficult to accomplish.

But geo-neutrinos are different. They are produced within our planet, through a process involving the radioactive decay of heavy elements such as thorium and uranium. Determining how much of the heat underneath the surface is caused by these particles could lead to a better understanding of how the convection forces driving the magma in the mantle function. These dynamics are extremely important in turn for gaining more insight into the driving forces behind tectonic plate movements, experts say. This movement is also tightly related to earthquakes and volcanism.

In order to detect any type of neutrino, a huge detector has to be used. The reason why the Borexino collaboration is buried so deep is because it needs to shield itself from the influence of cosmic rays, which also travel far underground. Only hydrocarbon materials are used inside the giant detectors, as heavy water would, for example, interfere with the readings. When a geo-neutrino passes through the detector, it may collide with a proton, a reaction that results in the creation of a neutron, a positron (the antimatter particle for an electron), a dual gamma-ray emission, and even small bursts of light.