14 June 2022 – The sea campaign for enlarging the KM3NeT/ARCA submarine telescope has been completed with full success!
During the last few days, all detection units loaded on Handin Tide for the second phase of the operation were carefully installed on the sea bottom. This was achieved at a record-breaking speed, with 7 detection units installed, connected and unfurled in less than 48 hours!
As a result of the campaign, the size of ARCA has more than doubled. It now comprises 19 detection units in operation, equipped with more than 10,000 photomultipliers,
We thank the teams which worked tirelessly offshore and onshore to reach this remarkable success. And we can’t forget that this was made possible by the hard work ongoing in the almost 30 integration sites of the Collaboration.
The activities at sea went around the clock during the campaign.
14 June 2022 – The sea campaign for enlarging the KM3NeT/ARCA submarine telescope which was started on June 2, has been completed today with a full success. As a result, data taking with ARCA has been resumed with 19 detection units in operation!
This represents a major step forward for the Collaboration, as this was the first time that a 2-weeks campaign was performed. The scope of the operation in fact was twofold: to upgrade the submarine network, by installing 2 new junction boxes in replacement of the junction box that we had been operating so far, and to install 11 new detection units (DUs). The operation therefore took place in two steps: after the first round of activities for installation of the junction boxes and the first 4 DUs, the ship went back to shore to pick up the remaining set of 7 DUs.
The campaign was performed with Handin Tide, of the FUGRO company, which had already performed the previous sea campaign for KM3NeT ARCA last year, sailing off from Malta.
All planned activities were performed with full success, including ancillary operations such as the replacement of one autonomous acoustic beacon on the sea floor. And a speed record was also established, with 7 detection units installed, connected and unfurled in less than 48 hours!
As a result of the campaign, the size of ARCA has more than doubled: It now comprises 19 detection units in operation, equipped with more than 10,000 photomultipliers,
The KM3NeT Collaboration wishes to thank the Handin Tide crew for their top-level performance, the KM3NeT teams which worked tirelessly offshore and onshore to reach this remarkable success, as well as all teams which work so hard at the almost 30 integration sites of the Collaboration to produce the DUs for building the apparatus.
Below is a gallery of pictures from the campaign. A log of the activities while the operation was ongoing is available on our blog.
Deployment of one of the junction boxes installed in the campaign.
6 June 2022 – The first round of activities of the ongoing sea campaign at ARCA has been completed.
In a summary, in the past week-end:
we installed two submarine junction boxes, one of which in replacement of the temporary junction box that we have used so far
the temporary junction box has been safely recovered
we moved all connections of the detection units already installed on the sea bed onto the new junction boxes
we installed 4 new detection units (where, by installation, one should understand that each detection unit was lowered to the bottom of the sea, carefully placed on the sea bottom, connected to the junction box and unfurled to reach its nominal, upright configuration)
Each of the steps above comprised dedicated tests, requiring careful coordination of the activities of the onshore and offshore teams.
And… the campaign is not yet finished! The ship is now heading back to Malta to load an additional set of detection units to install.
Stay tuned, as there will be more to report in the next days!
The first detection unit installed in this campaign gracefully splashes into the water, to start its journey down to 3,500 m depth.
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.
Aart Heijboer, physics coordinator of KM3NeT, showed the results of one year of data taking with ORCA6 and 100 days with ARCA6. The ‘6’ refers to the number of detection units in a detector used in the data analysis.
The ORCA detector is optimised to measure the oscillation parameters of neutrinos travelling through the Earth. Neutrino oscillation is a quantum mechanical phenomenon in which a neutrino created with a particular flavour – electron, muon or tau neutrino – can be later measured to have changed its flavour. In figure 1 below, it is evident that the data does NOT follow the flat blue horizontal line indicating the absence of neutrino oscillations. In other words, already with only six detection units, the ORCA6 detector ‘sees’ oscillations. In the second figure two oscillation parameters are plotted against each other. Clearly, the contour of ORCA6 is still wider than that of other experiments. More data with more detection units will make it narrower.
Also the ARCA detector, optimised for the search of high energy neutrinos from sources in the Universe, is well underway pushing the limits of the potential to discover sources of neutrinos down towards the expected limits of the full detector.
In the poster sessions KM3NeT physicists presented the details of many analyses being performed with the ARCA and ORCA detectors.
Aart Heijboer concluded at the plenary session that ARCA and ORCA will span eight decades in energy, that there is a rich variety of data analyses going on in the collaboration and that construction of the detectors is ramping up. Promising conclusions.
Very nice to have been invited to share the progress of KM3NeT with the community of neutrino (astro)physicists!
The KM3NeT Collaboration thanks the organisers of Neutrino2022 for an excellent edition of the conference. See you in two years time in Milano.
3 June 2022 – A new sea operation was started yesterday aiming at a significant enlargement of the ARCA neutrino telescope.
This is a major step forward for the Collaboration, as this is the first time ever that we launch a 2-weeks campaign. The scope of the operation in fact is twofold: upgrade the submarine network, by installing 2 brand-new junction boxes in replacement of the junction box that we have been operating so far, and to install new detection units (DUs). The operation will therefore take place in two steps: after the first round of activities for installation of the junction boxes and the first 4 DUs, the ship will come back to shore to pick up an additional set of DUs.
Handin Tide, which has already performed the previous sea campaign for KM3NeT ARCA last year, is the ship which will conduct this operation.
The ship left the port of Malta yesterday afternoon.
Remain connected, as we will be posting news about the operation while the action goes on – on our blog and on our social channels.
22 November 2021 – Four new detection units have been added to ORCA with a 5-day intense and successful sea operation.
The operation has been performed with two ships: the Castor, equipped for deployment and precise installation of the detection units on the sea floor, and Janus, equipped with a remotely operated vehicle used for inspecting and for connecting the new units to the submarine infrastructure.
You can read all details of the operation in the daily reports published in our ORCA-blog.
Data taking with 10 detection units has been started!
One of the new detection units of ORCA outboard of Castor, preparing to its journey to the seafloor, 2,500 m below.
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.
As the sea condition rapidly degraded during the day, it was decided to quit the campaign. The remaining detection units on deck will be saved for next time.
The final outcome of the campaign is: ORCA enlarged from 6 to 10 detection units!
The KM3NeT Collaboration is grateful to the heroic teams who have made such great effort onboard the two ships and in the shore station, as well as to all institutes which contributed to the construction of the detection units. We look forward to the next deployment campaign. Having said that: it’s time to resume data taking with an enlarged ORCA-10 now!
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.
The situation at the sea bottom is: two new detection units have been already added to the ORCA detector; a third one, after installation, connection and test, is awaiting unfurling, and a fourth one is also on the sea floor awaiting to be connected – next step will be to connnect this one.
The video shows the overboarding of the ROV from the Janus – this takes place by means of a so-called A-frame (the structure at the stern of the ship which, rotating, reaches outboard).
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.
The campaign is now continuing with deployment of the next detection units; a third one is already on the sea bottom, connected and tested. A fourth one has been deployed in the evening: we will keep going until the deck is empty or the weather changes (the forecast is not ideal for next week): which of the two will happen first?