lundi 16 décembre 2019

A breakthrough for high luminosity













CERN - European Organization for Nuclear Research logo.

16 December, 2019

The underground structures of the High-Luminosity LHC have been connected to the LHC tunnel 


Image above: On Friday, 13 December, Lucio Rossi, Leader of the HL-LHC project, Frédérick Bordry, Director for Accelerators and Technology, Fabiola Gianotti, CERN Director-General, and Oliver Brüning, Deputy Leader of the HL-LHC project, met in the LHC tunnel to celebrate the breakthrough at the LHC’s Point 1. (Image: CERN).

A handshake 100 metres underground isn’t something you see every day. But on Friday, 13 December, that’s exactly how Fabiola Gianotti, CERN Director-General, Frédérick Bordry, Director for Accelerators and Technology, Lucio Rossi, High-Luminosity LHC project leader, and Oliver Brunning, his deputy, marked the connection of the LHC tunnel with that of its successor, the High-Luminosity LHC. “This is a crucial milestone for the High-Luminosity LHC,” said Lucio Rossi. “These structures will house equipment that is needed to reach high luminosity.”

For the past 18 months, diggers have been at work underground to excavate the structures for the future accelerator. Work is focused on Point 1, where the ATLAS experiment is located, and Point 5, which houses the CMS experiment. Most of the equipment that will be installed in these locations is designed to boost the luminosity – or to put it another way, the number of collisions – at the heart of these two experiments.

A breakthrough for high luminosity

Video above: A short film presenting the milestone moment when the civil engineering teams made the junction that connected the HL-LHC with the LHC tunnel. (Video: CERN).

At each site, the underground constructions consist of a shaft around 80 metres deep, a service cavern, a 300-metre tunnel and four 50-metre tunnels connecting the new structures to the existing LHC tunnel. Around 80% of the excavations on the two sites are now complete: after having dug the shafts, the caverns and almost all of the two longer tunnels, the civil engineering companies are now working on the tunnels that will connect the new structures to the LHC tunnel. And as a result they connected the LHC with its successor, at Point 5 on 11 December and then at Point 1 the following day. “These connection works were completed with almost surgical precision, so as to minimise damage to the tunnel and to protect the LHC as much as possible from the dust produced by cutting through the concrete,” explains Pieter Mattelaer, Project Manager – Civil Engineering, High-Luminosity LHC Project.

A second connection between the new tunnels and the LHC tunnel should be completed before summer 2020. The underground structures will be fully completed by mid-2021, while the surface buildings will be completed by mid-2022.

A new schedule for the LHC and its successor

The LHC will restart in May 2021 and Run 3 will be extended by one year


Image above: The LHC will restart in 2021 after the intensive works of Long Shutdown 2 (Image: CERN).

The CERN Management has presented a new calendar for future accelerator runs to the Council, which met on 12 December. Under the new schedule, the LHC will restart in May 2021, two months after the initially planned date, and Run 3 will be extended by one year, until the end of 2024. All of the equipment needed for the High-Luminosity LHC, the LHC’s successor, and its experiments will be installed during Long Shutdown 3, between 2025 and mid-2027. The High-Luminosity LHC is scheduled to come into operation at the end of 2027.

For the last year, extensive upgrades of CERN’s accelerator complex and experiments in preparation for the next LHC run and the High-Luminosity LHC have been under way. Major work is being carried out on all the machines and infrastructures: the particle accelerator chain is being entirely renovated as part of the LHC Injectors Upgrade (LIU) project, new equipment is being installed in the LHC, where upgrades are also ongoing, and the experiments are replacing numerous components, even entire subdetectors, in order to prepare for high luminosity (read also about upgrades at ALICE, ATLAS, CMS and LHCb).

The High-Luminosity LHC will generate many more collisions than the LHC, accumulating ten times more data than its predecessor throughout its operation. This groundbreaking machine will thus be able to detect extremely rare phenomena and improve the precision of measurements of the infinitesimally small. In order to fully exploit the increased quantity of data, the experiments have embarked upon ambitious detector upgrade programmes. The extra time will enable them to ready themselves for Run 3 and, then, for the High-Luminosity LHC.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related links:

High-Luminosity LHC: https://home.cern/science/accelerators/high-luminosity-lhc

Large Hadron Collider (LHC): https://home.cern/science/accelerators/large-hadron-collider

ALICE: https://home.cern/news/news/experiments/upgrading-alice-whats-store-next-two-years

ATLAS: https://home.cern/news/news/experiments/wheels-motion-whats-planned-atlas-next-two-years

CMS: https://home.cern/news/news/experiments/whats-store-cms-detector-over-next-two-years

LHCb: https://home.cern/news/news/experiments/transforming-lhcb-whats-store-next-two-years

For more information about European Organization for Nuclear Research (CERN), Visit: https://home.cern/

Images (mentioned), Video (mentioned), Text, Credit: European Organization for Nuclear Research (CERN).

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