Deep-sea junction box of KM3NeT-Fr redeployed

dscn3374-node4 October 2016 – On 29th of September, the junction box of the deep-sea infrastructure at the KM3NeT-Fr Installation site of the ORCA detector was redeployed. 

After an intensive six day sea campaign, a fault in the electro-optical cable to shore has been repaired and the first of the seafloor network ‘nodes’ successfully reconnected. 

Thanks to the expertise of the Orange Marine team onboard the Raymond Croze ship, a section of the cable was replaced and the cable re-laid along its route on the seafloor 2500 m below. At the end of the 40 km long cable, the node was spliced into the system and gently lowered to its predefined position on the seafloor. After tests of the high-voltage system and verification of the optical fibre links, the onshore team in the control room at the Institut Michel Pacha in La Seyne declared the node fully operational.

 node-on-board node-at-surface node-in-deep-sea

A node is the power and data-communication hub of the deep seafloor network. Eventually up to five nodes will be needed to instrument the full ORCA array at the KM3NeT-Fr site. Already with this first node, more than twenty neutrino detection units along with various sensors for Earth and Sea science studies can be connected into the infrastructure.