Scientists overseeing Earth’s largest particle accelerator turned it on for the first time in three years this weekend to solve some of physics’ biggest mysteries.
The Large Hadron Collider (LHC), the powerful particle accelerator located at CERN near Geneva, Switzerland, restarted on Friday (April 22) after a three-year shutdown for maintenance and upgrades. The reactivation kicked off what scientists call Run 3, the LHC’s third science run, which will run experiments until 2024.
“Machines and facilities underwent major upgrades during the second long shutdown of the CERN accelerator complex,” Mike Lamont, CERN’s director of accelerators and technology, said in a statement Friday. “The LHC itself has undergone an extensive consolidation program and will now operate at even greater power and, thanks to major improvements to the injector complex, will provide significantly more data for the updated LHC experiments.” These experiments will build on the findings of the LHC during its run 1 (2009-2013) and run 2 (2015-2018).
Related: Large Hadron Collider will explore the forefront of physics after 3 years of shutdown
For its reactivation, the scientists triggered the LHC’s 27-kilometer ring to inject two beams of protons in opposite directions at an energy level of 450 billion electron volts. This is just an appetizer for even higher energy levels that the LHC will operate once it reaches its 13.6 trillion electron volts target for Run 3, the scientists said.
“These beams circulated in the energy injection and contained a relatively small number of protons. High-intensity, high-energy collisions are a few months away,” Rhodri Jones, who leads the beam department at CERN, said in the statement. represent the successful restart of the throttle after all the hard work of the long shutdown.”
The LHC’s three-year shutdown allowed scientists to make substantial upgrades to four key experiments at the particle accelerator. Its ATLAS and CMS detectors alone will receive more particle collisions than the last two runs combined, according to CERN. ATLAS (short for A Toroidal LHC Apparatus) detects the tiny subatomic fragments of particle collisions and is used to hunt for the Higgs boson, dark matter, and extra dimensions. CMS (short for Compact Muon Solenoid) is a general purpose detector that uses different systems for ATLAS-like observations.
In addition to ATLAS and CMS, the particle accelerator ALICE experiment for heavy ion collisions will be able to detect 50 times more collisions thanks to its upgrade, while another instrument, called LHCb, will see its detection capacity increase by a factor. than three, according to CERN.
“The unprecedented number of collisions will allow international teams of physicists at CERN and around the world to study the Higgs boson in great detail and put the Standard Model of particle physics and its various extensions through the most rigorous tests yet,” they wrote. CERN officials in the statement.
Two new experiments will be activated at the LHC for Run 3. Called the Forward Search Experiment (FASER) and the Scattering and Neutrino Detector at the LHC (SND@LHC), they should explore new physics beyond the Standard Model, measure how often forms of antimatter and explore the physics of cosmic rays and a strange state of matter called quark-gluon plasma.
It will take several weeks of commissioning work before the renovated LHC is ready for real scientific measurements. These science races are expected to start in the summer, CERN officials said.
Once Run 3 is completed in 2024, scientists at CERN will shut it down for another planned review that will include more updates to the massive particle accelerator. Once completed, these updates will allow scientists to rename the LHC the “High Luminosity Large Hadron Collider” once it reopens in 2028.