20 November 2020 – The KM3NeT Collaboration has published a new paper in which the details of the innovative deployment method for KM3NeT detection units is described.
The detection unit is different from moorings typically used for oceanography. In the case of KM3NeT, the mooring – the detection unit – the instrumentation is contained in transparent and thus unprotected glass spheres; two thin Dyneema ropes are used as strength members; and a thin delicate backbone tube with fibre-optics and copper wires for data and power transmission, respectively, runs along the full length of the mooring. Compared to other neutrino telescopes such as ANTARES in the Mediterranean Sea and GVD in Lake Baikal, the KM3NeT strings are more slender to minimise the amount of material used for support of the optical sensors. Moreover, deploying hundreds of strings in a period of a few years is demanding and the costly sea operations must be kept to a minimum. For all these reasons, for the installation of the KM3NeT deteciton units, a custom-made, fast deployment method was designed. Despite the length of several hundreds of metres, the slim design of the unit allows it to be compacted into a small, re-usable spherical launching vehicle instead of deploying the mooring weight down from a surface vessel. After being lowered to the seafloor, the detection unit unfurls to its full length with the buoyant launching vehicle rolling along the two ropes. The vehicle was dubbed LOM for Launcher of Optical Modules. The design of the LOM, the loading with a detection unit, and its underwater self-unrolling are detailed in the paper.
Pictures show an impression of the ideas for deployment by @Marijn; the technical design of the KM3NeT detection units that must be installed and the design of the LOM launcher vehicle; the first prototype of the LOM and the final version that is now regularly used for the installation of the detection units of the ARCA and ORCA detectors of the KM3NeT telescope.
Deep-sea deployment of the KM3NeT neutrino telescope detection units by self-unrolling
The KM3NeT Collaboration: S. Aiello et al
2020 JINST 15 P11027
L'articolo New paper: Deep-sea deployment of the KM3NeT neutrino telescope detection units by self-unrolling sembra essere il primo su KM3NeT.