Institute of Physics Publishing | via Phys.Org | 2016 June 23
Deep-sea array will soak up signals from neutrinos travelling through the cosmos to study the evolution of the universe and to discover more about the fundamental properties of these prized subatomic particles.
KM3NeT - a European collaboration pioneering the deployment of kilometre cubed arrays of neutrino detectors off the Mediterranean coast - has reported in detail on the scientific aims, technology and costs of its proposal in the Journal of Physics G: Nuclear and Particle Physics.
Neutrinos are ideal messengers from the cosmos. These stable, sub-atomic particles can travel long distances without being disturbed by matter or magnetic fields in their path. Their detection is prized by astronomers as neutrino-emitting sources such as the remnants of Super Nova explosions provide important clues to the evolution of our universe. The study of neutrinos could also help in expanding our knowledge of atomic physics. However, there is a catch. ...
It's a big undertaking. To detect neutrinos from the cosmos you need a massive site, which can then be used as a converter target as follows -
Firstly, a neutrino interacts with an atomic nucleus in the target medium to produce relativistic charged particles. Secondly, the passage of these relativistic charged particles through the medium produces so-called Cherenkov light (the typical blue light on pictures of nuclear reactors). And lastly, the Cherenkov light is detected by a 3-dimensional spatial array of incredibly sensitive photo-sensors. ...
The KM3NeT collaboration has developed what it believes is a cost-effective plan for building out this research infrastructure at the bottom of the sea. The phased rolled-out will consist of three so-called building blocks, where each building block comprises 115 strings of 18 optical modules (glass spheres containing 31 outward-facing photomultiplier tubes).
The strings, which can extend for several hundred metres, are anchored on the seabed and kept vertical by the buoyancy of the optical modules and the use of an additional buoy at the very top. These long chains of detectors are important, because they allow the scientists to reconstruct the trajectory of the incoming neutrinos. This data can then be used by researchers to identify the locations of the corresponding sources in outer space. ...
Letter of Intent for KM3NeT2.0 - S. Adrián-Martínez et al
- Journal of Physics G: Nuclear and Particle Physics 43(8):4001 (Aug 2016) DOI: 10.1088/0954-3899/43/8/084001
arXiv.org > astro-ph > arXiv:1601.07459 > 27 Jan 2016