Four more detector strings have been added to the KM3NeT neutrino detector in the deep sea off the coast of Toulon. The French section of the particle telescope now has 42 strings.
During an offshore operation, the strings were lowered to a depth of over 2.5 kilometers from a lift vessel and connected to the network using an unmanned submersible. The anchored vertical strings, each containing 18 light sensor units, are now collecting data.
KM3NeT is a detector designed to detect neutrinos from space. Nikhef is one of the main participants in the project, which is steadily expanding. Large sections of the detector are being built at Nikhef’s facility in Science Park in Amsterdam.
KM3NeT consists of two sections: ORCA near Toulon and the larger ARCA near Sicily in Italian waters. ORCA was built to study the properties of neutrinos themselves. ARCA searches for the sources of these particles in the sky.
Once completed, ORCA and ARCA will together monitor one cubic kilometer of dark seawater. Neutrinos very rarely collide with water molecules. When this happens, charged particles are released that leave light trails in the water, which are recorded by the sensors. The trails can be reconstructed from all the signals.
During the deployment operation last weekend, the existing detection units were inspected, and an acoustic beacon was retrieved for maintenance. A number of traps for biological material were also retrieved; these are used to study biological fouling at great depths.
