Second node of ORCA installed
13 August 2025 – Last week we installed a second submarine node for the ORCA neutrino telescope. It is an important step in preparation of the next deployments of detection units for ORCA.
KM3NeT - ORCA
Tau neutrinos and neutrino mixing with ORCA6
6 February 2025 – We present a new paper with the title ‘A study of tau neutrinos and non-unitary neutrino mixing with the first six detection units of KM3NeT/ORCA‘.
Welcome ARCA33 and ORCA24!
28 October 2024 – The latest sea campaigns at both the KM3NeT’s ARCA and ORCA sites have led to major progress in expanding detector installations and improving calibration systems.
The number of detection units in operation in the deep sea has been increased to 57: 33 in ARCA and 24 in ORCA.
Three more detection units for KM3NeT/ORCA
1 May 2023 – During a two days sea operation, 27-28 April 2023, three detection units were successfully connected to the ORCA detector of KM3NeT in a record time of just over 24 hours. In addition, an acoustic beacon was recovered for battery replacement. The total number of deployed ORCA units is now 18, as visible in the sonar scan above.
KM3NeT@neutrino2022
Fifty years ago, in 1972, the first neutrino conference was held in Hungary, because the organisers were not satisfied with the subdued position of neutrino interactions at the international conferences at that time. Nowadays, the neutrino conference is one of the major conferences in neutrino (astro)particle physics. Neutrino2022 took place in virtual Seoul, 30 May-4 June, 2022 and of course KM3NeT was there to show the results of data taking with the first detection units of ARCA and ORCA.
Welcome, ORCA-10!
22 November 2021 – Four new detection units have been added to ORCA with a 5-day intense and successful sea operation.
Sea campaign completed: 10 detection units in operation at ORCA
22 November 2021 – Excellent progress today, with the work finalized on the two detection units lately deployed: after a confirmation from the tests that both were ok, the unfurling was started of the two units. The launcher vehicles were safely recovered from the Castor; the ROV inspected both units after unfurling, confirming that both are in nominal configuration. A new functionality test was then performed from the shore station to ensure that both detection units work nominally.
News from the ORCA campaign – hard work ongoing, bad weather approaching
21 November 2021 – The weather forecast does not look promising for next days. The main effort today was spent on some tuning of the equipment and preparation to next steps.
Two new detection units added to ORCA… and counting
20 November 2021 – It was night and day again. The work continues around the clock when you are at sea. The second detection unit was also deployed, connected and tested last night. After that, unfurling was performed for the two detection units. A final test was then made from the shore to check that the two units are ok even after unfurling, et… voilà: ORCA is enlarged to 8 detection units.
First day of activity at the ORCA site
19 November 2021 – The first day of activity has gone at the ORCA site. Most efforts today were aimed at getting everything well prepared for the action. The first detection unit was then deployed to the sea bottom, precisely placed on the sea floor and connected to the submarine infrastructure. The tests performed from shore confirm that the dection unit is nicely working, and it now awaits to be “unfurled” to its work configuration. Deployment of the second detection unit has been started in the evening.
