After three years of maintenance and upgrades, the Large Hadron Collider — one of the most powerful scientific instruments ever built — has whizzed past its own record. In preparation for its third major run of experiments, the particle accelerator has created the most energetic beams of protons ever made by humans. The particles went racing around the 17-mile (27 km) tunnel near Geneva, Switzerland, with an energy of 6.8 trillion electronvolts (TeV).
Today the two #LHC pilot beams of protons were accelerated, for the first time, to the record energy of 6.8 TeV per beam. 🎉— CERN (@CERN) April 25, 2022
After #restartingLHC, this operation is part of the activities to recommission the machine in preparation of #LHCRun3, planned for the summer of 2022. pic.twitter.com/8NZ6nNJSVf
"This, of course, is an important day for us... but it's only the start of a very long commissioning period which [will] bring us to actually collide the two beams for the experiments and provide the highest-energy collisions," says Jörg Wenninger, head of LHC beam operation section and LHC machine coordinator. Beams should start colliding within a couple of months, he says.
This is the latest in a series of new records
The LHC broke its first record (and became the world's most powerful particle accelerator) in 2009, just after it began operation. The beam of protons was accelerated to an energy of just over 1 TeV, beating out Fermilab's Tevatron accelerator near Chicago, Illinois.
"Then one year later, we pushed to 3.5 TeV," Wenninger says. After setting yet another record, LHC was shut down for maintenance and to consolidate some of the magnets that control the proton beams. "This allowed us in 2015 to reach 6.5 TeV, again a new world record," he says. That satisfied the particle physicists who rely on LHC data for three years. During the second long shutdown, which has just ended, researchers and technicians "did further consolidation of the safety system of the magnet." Those tweaks enabled today's new record and brought the team "very close to the designed energy of the LHC, which is 7 TeV," he says.
It's all in preparation for LHC's "Run 3"
This record isn't the only upgrade that scientists at the LHC will be unveiling over the coming weeks. Several of the experiments at the accelerator have significantly increased the amount of data they're capable of collecting, opening the door for new (and perhaps surprising) discoveries.
“The machines and facilities underwent major upgrades during the second long shutdown of CERN’s accelerator complex,” says Mike Lamont, Director for Accelerators and Technology at CERN, the organization that runs the accelerator. “The LHC itself has undergone an extensive consolidation programme and will now operate at an even higher energy and, thanks to major improvements in the injector complex, it will deliver significantly more data to the upgraded LHC experiments.”
During Run 3, each of the collider's two general-purpose detectors — ATLAS and the CMS — will monitor more collisions than they did during the first two runs put together. The capacity of other instruments has increased by as much as a factor of 50. Researchers across the world will use that data to peer deeper than ever into some of the most puzzling and fundamental mysteries in physics.