CERN Began Upgrading Large Hadron Collider Magnets
The research facility has started replacing critical focusing magnets to increase beam luminosity for future particle physics experiments.
Updated on Sept. 27, 2026 in Physics
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CERN has initiated the removal of aging focusing magnets at the Large Hadron Collider to facilitate a significant performance upgrade. This effort marks the beginning of the accelerator's third long shutdown period.
Why it matters
Replacing the nearly two-decade-old hardware increases collision luminosity, allowing the ATLAS and CMS experiments to collect higher volumes of data. This modernization ensures the 27-kilometer machine remains capable of supporting high-energy particle research.
The upgrade replaces 28 existing superconducting magnets with new units capable of 11.3 tesla fields, a 40% increase over the original hardware. The project requires the installation of 16 cryostats and 28 cryo-assemblies along the 27 km circumference of the accelerator.
The players
CERN
The intergovernmental organization that operates the largest particle physics laboratory and the Large Hadron Collider.
ATLAS
A general-purpose particle physics experiment designed to observe phenomena involving highly massive particles.
CMS
A compact muon solenoid particle detector experiment designed to investigate a broad range of physics phenomena.
The details
CERN is disassembling accelerator sections on both sides of the ATLAS and CMS experiments to access the inner triplet magnets. These cryostats — specialized vacuum vessels that maintain temperatures near absolute zero — house the superconducting magnets used to focus particle beams before collision. By replacing the aging inner triplets, the facility will achieve the higher beam intensity required for upcoming experimental runs.
Timeline
Original inner triplet magnets were installed between 2005 and 2007.
Work to take apart the accelerator sections began on September 7, 2026.
The first connection between magnets was cut the week of September 27, 2026.
The first new quadrupole triplet is expected in the tunnel in early 2029.
The Tech Race
This project represents a critical hardware evolution within the Large Hadron Collider third long shutdown, essential for maintaining the facility's global lead in high-energy physics. The upgrade keeps the laboratory's infrastructure competitive with proposed future accelerator designs by maximizing the output of existing tunnel geometry.
The upgrade is a long-term infrastructure project that directly affects the data collection capabilities of international physics research collaborations. While there is no immediate change for the public, the higher luminosity enabled by these magnets will influence the precision of particle physics findings released in the coming decade.
The takeaway
CERN is systematically enhancing the power and focus of its particle beams to push the limits of modern physics. Observers should track the 2029 installation timeline to see if the new 11.3 tesla magnets successfully meet the projected data collection requirements.
What happens next
The installation of the first new quadrupole triplet is scheduled for early 2029, marking the next major technical milestone in the accelerator's upgrade path.
Further reading
For broader context on current high-energy research, see the latest developments in Physics.
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