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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.

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!

Approaching the ORCA submarine junction box at 2,500 m depth – in the foreground is the connector that the ROV is preparing to plug on it.

The team onboard the Janus – on one of the screens is the sonar image of the ORCA telescope, showing the nodes and the detection units on the sea floor. Note that the operation was performed respecting all applicable rules for protection against COVID-19 – the team got so close together only for the purpose of the picture.

The team onboard the Castor showing the ’10’ sign in front of a recovered launcher vehicle.

The onshore team. The featured instrument is an Optical Spectrum Analyser, showing the signals of the 10 detection units of ORCA. Note that the operation was performed respecting all applicable rules for protection against COVID-19 – the team got so close together only for the purpose of the picture.

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.

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).

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.

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?

After unfurling of a detection unit, the launcher vehicle on which the unit is installed for deployment reaches the surface and is recovered for next campaigns.

Inspection of a detection unit, after touchdown on the sea floor (~2,500 m depth). The unit featured here is the fourth one which has been deployed in this campaign.

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.

Today was also the last day of our joint ANTARES-KM3NeT online Collaboration meeting, which ended with a cheerful activity to enjoy each other’s company even from a distance – you can read more about the meeting here.

The tho ships in action at the ORCA site: Castor (in the foreground) is equipped for deploying and accurately placing the detection units on the sea floor, while the Janus (in the background) is equipped with a ROV for submarine connections.

The movie shows the overboarding of one of the new detection units of ORCA.

Congratulations to Rebecca Gozzini

The KM3NeT Collaboration congratulates Sara Rebecca Gozzini, who has received a fellowship from the Program to support talented researchers – GenT Plan – of the Generalitat Valenciana (Valencian regional government) in Spain. The fellowship has a duration of 4 (+ 2) years to develop a research project at the Instituto de Física Corpuscular, IFIC, in Valencia and is thought as a tenure-track position promoted by the regional government for the consolidation of young researchers with international projection.

Rebecca joined ANTARES and KM3NeT in 2017. She took charge of different searches for dark matter: search for Galactic Centre WIMPs, search for heavy secluded dark matter, and a combined analysis with IceCube. She currently coordinates the working group ‘Dark Matter and Exotics Physics’ in KM3NeT.

The project presented by Rebecca for her GenT application, “Search for new physics signatures and measurement of fundamental neutrino properties with the KM3NeT telescope”, will have as priority objectives the search for dark matter signatures in KM3NeT, as well as new physics phenomena associated with neutrinos, such as non-standard interactions and others. The grant awarded to Rebecca includes also a budget to hire two PhD students.

The GenT Plan of the Generalitat Valenciana was born in 2017 as a commitment for the recovery, attraction and consolidation of researchers of international excellence in the Valencian research, development and innovation system, in all areas of knowledge to develop their R & D projects in public universities and research centres of the Valencian Community. Paco Salesa and Agustín Sánchez, also members of KM3NeT, are currently working at IFIC thanks to this initiative, too.

Limits on Galactic Centre WIMPs with ANTARES and KM3NeT — Limits from the search for a WIMP signal from the Galactic Centre with ANTARES and KM3NeT (plot presented by Rebecca at the 37th International Cosmic Ray Conference, 2021)

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”!

ARCA enlarged with 3 new detection units!

14 September 2021 – the ARCA telescope is now enlarged with 3 new detection units.

The procedure for installing a detection unit in ARCA is as follows: firstly the detection unit is lowered from the deck of the ship. When it reaches a low level above the sea floor, the ROV (the submarine vehicle operated from the ship) comes in play: it takes a bridle and helps to guide the detection unit to its target position on the sea bottom; it also rotates it so that the panel for connection of the submarine cable faces the direction of the submarine junction box. Only at that point, the detection unit is lowered on the sea floor. After a quick visual check, the ROV detaches the deployment line. The ROV then picks up the cable which had been previously routed on the sea bottom and which is connected to the junction box on the opposite end, and plugs it to the detection unit. Then the onshore team is asked to perform a first round of test to ensure that the detection unit meets its functional requirements. After that, the ROV opens a release mechanism that lets the deployment vehicle on which the detection unit is furled free to go. The vehicle is buoyant and starts coming up; while doing so, it rotates, leaving the detection unit, which is tied to the anchor on the sea floor, upright – a sort of giant, and reversed yo-yo!

After unfurling, the deployment vehicle is recovered from the ship, to be reused for next deployments.

A final test of the newly installed and unfurled detection unit is then performed to confirm that the detection unit works as expected.

This happened three times today!

An optical spectrum analyzer is used in the shore station for a check of the quality of the communications with the detection unit (almost 100 km away, 3,500 m deep). Each signal (in the form of a peak) in the plot corresponds to one of the optical modules of the detection unit. Believe it: when this plot appears on the screen of the instrument, it is a fantastic reward for all the hard work done in the sea campaign and before!

A very busy day, offshore and onshore

13 September 2021 – Still a day packed of activities today!

The status at the moment is that all interlink cables have been layed down on the sea floor and two detection units have been deployed and connected to the junction box. The detection units are still furled on their launcher vehicles; they will be allowed to unfurl tomorrow – since the launcher vehicle has to be recovered from the ship after it reaches the surface, it is better to perform this operation in the daylight.

Pre-unfurling functional tests performed from the onshore control station show that those first two detection units are in good order.

Deployments of the next detection units will continue during the night.

The onshore team in the control station at Portopalo di Capo Passero, Sicily, Italy.

Good progress, despite adverse sea condition

12 September 2021 – there has been good progress in the operation so far!

The two cable reels are also deployed. The cables for connecting four detection units are already layed on the sea bottom and connected to the junction box. There is only one cable left to install.

While proceeding with these activities, however, the weather conditions worsened. The sky was still sunny, but waves mounted high: “We have a lot of sun here, but we are dancing a lot” commented Daniele Vivolo, who is among the KM3NeT team onboard the ship.

In such situation the risks when putting the equipment in water increase significantly. It was therefore decided to put the operation on hold, waiting for an improvement of the sea state.

In late afternoon, the sea had calmed down significantly, and the operations were resumed.

As we write this post, the first detection unit of the set of five included in this campaign is already in water, travelling into the deep, dark sea, down to 3,500 meters depth. There it will meet the ROV (the submarine vehicle operated from the ship), which will take care of the next steps: to assist in carefully positioning the detection unit on the sea bottom and to connect it to the cable already in place. Have a safe trip!

In the movie: the first detection unit is prepared for deployment.

First day of deployments at the ARCA site

11 September 2021 – operations are proceeding smoothly on Handin Tide.

The two new optical beacons of the positioning system are already placed on the sea bottom – these are autonomous devices not requiring a connection to the sea-floor network.

The deployment of the two reels carrying the long interlink cables for the detection units is proceeding. Installation of these cables requires time, because once a reel has reached the sea bottom, each cable has to be spooled off and layed down on the sea floor. These cables will be later used for connecting each detection unit to the submarine junction box which is already at the site (and connected to the 6 detection units already installed).

Once installation of the cables is completed, the deployment of the detection units can start – tomorrow!