How exactly do you launch a cubic kilometre neutrino telescope in the heart of the Mediterranean sea? That’s the subject of our Image of the Week, and we look at the launch vehicle for KM3NeT. If you want to find out a bit more about what KM3NeT is about, check out our interview with spokesperson Maarten de Jong.
To build the telescope the team is creating a large array of detectors under the sea, but how do you get them there? The answer lies in the team’s clever launch vehicle, pictured below.
The launch vehicle is cleverly designed to host a single string of digital optical modules – 18 in all on one string. The vehicle sinks to the sea floor with the help of its anchor, and once safely connected to the KM3NeT network, the sphere will slowly rise allowing the carefully coiled string to unravel. When the vehicle reaches the surface, it can be recovered and reused. The strings are kept vertical by a submerged buoy, helping to reduce the impact of undersea currents.
Each string will be carefully placed according to the KM3NeT design. There are two parts to this: ARCA (Astroparticle Research with Cosmics in the Abyss) and ORCA (Oscillation Research with Cosmics in the Abyss). The two experiments are at different sites, and although both designs are very similar, the configuration differs to adjust for the physics being sought. This means a different separation of both the strings and the optical modules held by the strings. The ARCA strings/modules will have a wider separation, as they seek to identify the very highest energy astrophysical neutrinos at the TeV scale, whilst ORCA’s will be closer together to target atmospheric neutrinos in the GeV range.
You can read the full details about how the telescope will work and all the physics behind it in JPhysG, with the KM3NeT Letter of Intent (Open Access)
This work is licensed under a Creative Commons Attribution 3.0 Unported License
Image: From KM3NeT Letter of Intent, S Adrián-Martínez et al 2016 J. Phys. G: Nucl. Part. Phys. 43 084001. CC-BY 3.0 as above.