Ocean Universe

KM3NeT Neutrinos Scanner Test on Mediterranean Sea

Scientists from all over Europe to explore the strange particles that reach the Earth from outer space, with a huge sensor. The first detectors in an experimental field that has a volume of several cubic, have now been installed.

Astro scientists are fascinated by neutrinos, tiny particles that penetrate everything, as if it were non-existent. You flit through people, houses, cars and rock. They rarely react with another atom core. They come from the Sun and cosmic processes and disasters that lie back millions of years. There are nearly two dozen sometimes elaborate experiments worldwide, to explore the neutrinos more closely.

New window to the universe

Now another addition, which is still more expensive than IceCube, a testing ground in the ice of the South Pole. There are 5160 sensors in a volume of one cubic kilometer. The Assembly of KM3NeT has begun that, so the home page of the experiment, opens a new window to our universe. With a size of several cubic, it exceeds the sensor area at the South Pole several times.

Coiled Strings on the spherical part of the installation
Coiled Strings on the spherical part of the installation

The structure is however similar to. In the depths of the Mediterranean, not a beam reach, countless sensors such as a vertical string of pearls are installed. They respond to Cherenkov radiation, which is known as the bluish light of storage pools for spent fuel from nuclear power plants.

Exactly the same light emissions cause clashes of neutrinos with atomic nuclei of elements that can be found in sea water, about sodium and chlorine, which is salt, or the oxygen of the water.

Anchored at a depth of 3500 meters

Each string of pearls known as string, is 700 m long and carries 18 sensors. Before the Assembly they are similar to yarn, coiled on a but shaped frame. The lower end is attached by a remote-controlled underwater robot in the sea floor. Then, a buoy moves up the frame, so that the string will be processed. The buoy will make sure that the string of pearls is always perpendicular to the sea.

Experts on board the installation vessel of Ambrose installed tide the first KM3NeT string at a depth of 3500 m now Southeast of Sicily. The data is transmitted via an underwater optical fiber cable about 100 km distant data center in the Italian Portopalo di Capo Passero.

The first neutrinos are already on record

Marco Circella, technical director of KM3NeT: “the great depth of the sea protects the telescope not only completely against light off, but also largely against particles produced by cosmic rays in the atmosphere.” You are not nearly as powerful as neutrinos. Therefore they are swallowed in the upper layers of the water.

Professor Uli Katz, physics and software Director of KM3NeT and AstroPżhisics at the University of Erlangen in Nuremberg, is already in the early stages of the Assembly completely thrilled: “within a few hours the first particles have been reconstructed already by reactions of cosmic rays in the atmosphere.”

Scientists from more than two dozen European universities are involved, including the in Bamberg, Erlangen-Nürnberg, Würzburg and Tübingen.