KM3NeT - ARCA sea campaigns

Liveblogs during sea campaigns for ARCA

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.

Despite bad weather at the ARCA site, the so-called Phase-1 part of the apparatus was completed, while construction of Phase-2 was started with the installation of two new junction boxes, three detection units (exploiting a new data acquisition architecture), and calibration components. The operations also included important maintenance tasks, such as recovering and replacing acoustic beacons. All optical modules of the deployed strings are fully operational. KM3NeT/ARCA now comprises 33 detection units.

At the ORCA site, a 60-hour calm weather window allowed the team to deploy the Calibration Unit (Calibration Base+Instrumentation Unit) and to install an additional detection unit. After these successful installations, node 1 of ORCA is complete and fully functional, an important milestone in the construction of ORCA. The total number of functional detection units at ORCA has now reached 24.

These recent efforts at both sites underscore KM3NeT’s expanding capability in detecting and studying neutrinos from the sea’s depths. The whole Collaboration extends its gratitude to the offshore and onshore teams whose hard work made these successful operations possible.
A furled detection unit ready for the deployment at the ORCA site
ORCA offshore team on the Castor 02 ship
Components for ARCA on the deck of the Optimus Prime ship: in the foreground is one junction box, behind it there are a couple of spools with the submarine interlink cables and then some detection units
ARCA onshore shift crew at the site of Portopalo

 

 

 

 

 

 

 

 

 

 

 

ATLAS comet visible from the harbour of Portopalo di Capo Passero

 

Sonar scan of the ORCA site taken by the ROV at the end of the operation. The anchors of the detections Units (DUs), the junction box (JB1), the Calibration Base (CB), the Instrumentation Unit (IU) and the Module Instrumentation Interface (MII) are all visible.

ORCA enlarged with four new detection units

15 June 2024 – A new marine operation took place in the last week for enlarging the ORCA deep-sea neutrino telescope.

Taking advantage of a spot of good weather of 48 hours, four new detection units were added to the apparatus.

For each of such units, the following steps were required: installation on the bottom of the sea, connection to the apparatus, functionality check, unfurling from the launcher vehicle, final test to check the functionality post-unfurling and recovery of the launcher vehicle. During the operation one acoustic beacon, which was in need of refurbishment, was recovered from the bottom of the sea.

The campaign was performed with two ships and a deep-sea ROV. A team onshore performed all needed tests on the newly installed detection units.

After the new installations, ORCA now comprises 23 detection units; only one more detection unit is needed for completing all connections on the first of the submarine nodes of the apparatus.

Many thanks to all teams involved for this important step forward!

The deck of Castor-2 of Foselev Marine loaded with the new detection units awaiting deployment, at dawn, while starting up the campaign.

 

A detection unit splashing to start its journey to the bottom of the sea.

 

Into the blue!

 

 

KM3NeT/ARCA enlarged to 28 Detection Units

10 October 2023 – An important two-week marine operation has been successfully carried out at the KM3NeT ARCA site, offshore Capo Passero, Sicily in September.

The campaign was performed with the Optimus Prime, equipped with a FUGRO underwater vehicle (ROV). The ship set sail from Malta on Monday, 11 September and came back to the port at the end of the operation on Thursday, 23 September.

The operation was among the last activities of PACK, a project supported by MUR (the Italian Ministry of University and Research) for the period 2019-2023, aimed at enlarging the deep-sea telescope and at enhancing the KM3NeT facilities in Bari, Caserta and Naples.

Soon after completing the operation, the commissioning of the enlarged ARCA telescope was started.

ARCA now comprises 28 detection units, which are altogether equipped with 504 Digital Optical Modules, with a total of more than 15,000 photomultipliers.

Deployment of a detection unit from Optimus Prime
The start of the unfurling of a detection unit as seen from the ROV control room onboard the Optimus Prime.
Tests of a newly deployed detection unit from the shore station in Portopalo di Capo Passero

Major upgrade of ARCA’s seafloor network

22 November 2022 – After 4 years of  activities carried out by the Italian funding agency INFN and Alcatel Submarine Networks, part of Nokia, the new subsea network for KM3NeT ARCA, funded under the Idmar regional project in Italy, is now complete.

The new system comprises a 100 km long electro-optical cable, equipped with 48 optical fibres for detector control and data communication and two electrical conductors for power distribution, connected to the shore station control and power feeding equipment, that can deliver up to 80 kW offshore. The cable is bifurcated in order to serve the two building blocks foreseen in ARCA.

During a 10 days long sea operation, which ended on November 17th, a cable termination frame (CTF) was installed on the northern branch of the cable. To this purpose the end of the cable, which was deployed already in 2020, was recovered from the sea floor and connected to the CTF onboard the deployment ship – the Ile d’Ouessant of Alcatel Submarine Networks. Then the CTF was carefully deployed to the target position on the sea floor. Extensive tests were done before and after the deployment to ensure its nominal behaviour.

The CTF is a large-size, 12-ton component which is equipped with four medium voltage converters and a total of 16 electrical and optical subsea connectors for connecting a set of submarine junction boxes to which the detection units will be in turn connected.

With this installation the connectivity and power transmission capabilities of the network have been increased by a factor four compared to the first part of the network, used to run the set of junction boxes and the first 30 detection units of ARCA Phase 1. This will allow for the completion of the construction of the first building block of ARCA and prepares the field for the installation of a second CTF on the other branch of the cable for the second building block.

The CTF at the end of the integration.
CTF onboard Ile d’Ouessant.
Overboarding of the CTF.

New sea campaigns at both KM3NeT sites

12 September 2022 – New sea campaigns were performed last week for both ARCA and ORCA. The purpose was to prepare the field for next installation phases of the detectors as well as to deploy new detection units and acoustic beacons – the latter are autonomous calibration devices which run on batteries and need to be replaced after some time.

The number of detection units in operation in the deep sea has been increased to 32 (comprising almost 18,000 photomultipliers): 21 in ARCA and 11 in ORCA.

After installation of a third junction box at the ARCA site, this site is now fully equipped for hosting the so-called Phase-1 of the project, comprising the first 31 detection units and the calibration unit of the apparatus.

The ARCA sea campaign represented the final action of the IDMAR project in Italy, supported by Regione Sicilia.

These operations were made possible by the dedication of hardware teams and the onshore and offshore teams at the two sites – the Collaboration is very grateful to them.

The newly added junction box of ARCA on the sea bottom.
Detection unit deployment at the ORCA site.

Sea campaign for ARCA concluded: welcome, KM3NeT/ARCA19!

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.

The shore station during the campaign – more than 30 people were involved in the onshore team for this campaign.

Activities at sea being resumed at the ARCA site

11 June 2022 – Due to the adverse weather conditions of the last days, the schedule of the sea campaign had to be redefined.

Here is the updated plan:

  • the ship left Malta this afternoon, to be back at the ARCA site tonight
  • the deep sea activities will be started already during the night
  • DU deployments will be started tomorrow
  • end of the operation is foreseen for early next week

Good luck to our offshore and onshore teams!

Empty LOMs (the launcher vehicles used for deployment and unfurling of the detection units) on the dock in the Malta port after the first phase of the sea campaign.
The deck of the Handin Tide loaded with detection units and their cable trays for the second phase of the campaign.
The Handin Tide leaving the port of Malta this afternoon.

Intermediate outcome of the ARCA campaign: 2 junction boxes and 12 detection units operational

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!

Preparation to deployment of the first detection unit to be installed during the campaign. On the right of it is one of the junction boxes awaiting installation, on the left the temporary junction box recovered from the sea floor.

 

The first detection unit installed in this campaign gracefully splashes into the water, to start its journey down to 3,500 m depth.

 

New sea operation started at ARCA

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.

A set of KM3NeT DUs ready for deployment in the port of Malta earlier this week.

 

Loading of a KM3NeT DU onto the Handin Tide.

The Handin Tide sailing off from Malta in the afternoon of yesterday, June 2.

Time to resume data taking in ARCA

15 September 2021 – after the recovery of two old detection units, already left disconnected after previous sea campaigns – the so-called PPM-DU (Pre-Production Model of Detection Unit), a 3-digital optical module unit used for qualification of the project in the sea as early as in 2014, and one of the first prototype full-size detection units deployed in spring 2016, the sea campaign of ARCA has been completed today.

A lot of good work has been done in this intense week – and we are very grateful for that to the onshore and offshore teams. We also thank all the various institutes which contributed to the construction and preparation to deployment of the detection units – in next entries on this blog we will report on these demanding activities.

As a summary, during this sea campaign:

  • the positioning system has been maintained by installing two acoustic beacons and recovering an exhausted one (these are autonomous devices running on batteries which need to be refurbished in due time)
  • five interlink cables were installed on the sea bottom
  • three new detection units were installed, i.e.: deployed to the sea bottom, connected to the submarine infrastructure, unfurled to their nominal shape (standing for almost 700 m above the sea floor) and proved to work
  • the launcher vehicles of the three installed detection units and the cable trays used for deploying the cables were of course recovered, to be reused for next campaigns

After completing this set of operations, Handin Tide safely sailed back to the port of Malta.

Note that it was decided not to install the remaining two detection units which were onboard the ship, due to a mechanical issue that will be solved. These two detection units have been taken back to shore. After adequate refurbishment, they will be added to those already in preparation. Nothing is lost therefore: they will be included in the next sea campaign.

In the end… it’s time to resume detector operation of ARCA now!

The KM3NeT Collaboration is very grateful to the onshore (in the picture) and offshore teams for their hard work, instrumental for the success of this sea campaign – note that the full operation was performed respecting all applicable rules against COVID-19: our onshore team got so close together only for the time of a… “cheese”!