This year, the Large Hadron Collider (LHC) will restart at the record collision energy of 13 TeV, following a two-year long shutdown (LS1) for planned maintenance. To mark this, today saw the LS1 activities coordinator symbolically handing over the LHC key to the operations team. The team will now perform tests on the machine in preparation for the restart this spring.
After three years of highly successful running, the LHC was shut down for maintenance in 2013. Since then, engineers and technicians have been repairing and strengthening the 27-kilometre accelerator in preparation for its restart at 13 TeV. Some 18 of the 1232 dipole magnets that steer particle beams around the accelerator were replaced, and more than 10,000 electrical interconnections between the magnets were strengthened. The LHC’s vacuum, cryogenics and electronics systems were also consolidated.
"It's important to stress that after the long shutdown, the LHC is essentially a new machine," said CERN Director-General Rolf Heuer in his New Year address at CERN last week.
The collision energy of 13 TeV is a significant increase compared with the initial three-year LHC run, which began at 7 TeV and rose to 8 TeV. In addition, in the run that starts this year, bunches of protons in the accelerator will collide at briefer intervals – 25 nanoseconds(ns) between them instead of 50 ns – and the beams will be more tightly focused. All these factors are aimed at optimising the delivery of particle collisions for physics research.
With collisions at energies never reached in a particle accelerator before, the LHC will open a new window for discovery, allowing further studies of the Higgs boson and the potential to address unsolved mysteries such as dark matter.
The LHC is CERN's flagship machine, but the accelerator complex also provides a broad programme of research that makes many contributions to fundamental physics. The long shutdown has allowed teams throughout CERN to upgrade experiments, detectors, accelerators and equipment.
In addition, the laboratory has continued to nurture its collaborations around the world with involvements in future collider studies, showing CERN’s dedication to the future of particle physics at the very forefront of knowledge.
It will be a busy year ahead, and with so much in store the laboratory looks forward to LHC Season 2 and more!