Final run for the current LHC accelerator (but more to come) - Nikhef

Final run for the current LHC accelerator (but more to come)

Home News Final run for the current LHC accelerator (but more to come)

4 June 2026

At CERN, the detectors at the LHC are conducting their final round of measurements before a three-year shutdown for a major overhaul of the accelerator. The LHC, the world’s largest particle collider, has been in operation since 2008.

Until June 14, the Large Hadron Collider will continue to accelerate lead ions for measurements of quark-gluon plasmas in the specialized ALICE detector, as well as in the other detectors—ATLAS, CMS, and LHCb. The accelerator will then remain in operation for intensity tests, machine tests, and beam stop tests until June 29.

Afterward, the keys to the LHC control room will be symbolically handed over to the project leadership for the High Luminosity LHC project. In the coming years, the accelerator at CERN will undergo extensive modifications to be able to sustain and deliver much more intense proton beams.

On June 11, CERN will host a live video link with the LHC control room to showcase the completion of the measurements and highlight the performance of the machine and its experiments.

The LHC accelerator near Geneva, a 27-kilometer-long underground facility with superconducting magnets and 7 TeV of beam energy, was commissioned at CERN in 2008 as the successor to the LEP electron-positron accelerator in the same tunnel. A key objective was to demonstrate the predicted Higgs mechanism that gives elementary particles their mass.

In 2012, the discovery of the Higgs particle using the LHC by ATLAS and CMS made global headlines. Since then, much of the research involving proton-proton collisions in the LHC has focused on the details of this new and crucial Higgs particle.

The HL-LHC is scheduled to go into operation in 2030 and will then deliver ten times as many proton-proton collisions for experiments over its lifetime as the existing LHC. With much more data, higher precision is possible in studies of the Higgs particle and tests of the Standard Model.

The ion run marks the final stage in the LHC’s history. As early as May 20, the last protons circulated in the 27-kilometer-long underground accelerator ring. For ATLAS, CMS, and LHCb, this brought the Run-3 measurement period to a close. This is now followed by the so-called long shutdown, or LS3, during which no experiments are possible.

The upcoming modifications to the LHC accelerator are very extensive. Parts of the existing accelerator will be replaced with more advanced beam technology, magnet systems will be improved or replaced, and new cooling systems will be installed. In recent years, additional tunnels and systems have already been constructed at several locations in the ring.

The upcoming higher beam intensities also pose a challenge for the detectors in the accelerator ring, as this means many more collisions must be observed and recorded simultaneously. The deluge of collisions and data places higher demands on the sensors and detectors, as well as on the data networks and computing infrastructure of the experiments.

Nikhef is closely involved in upgrading the experiments in which the institute participates. For the ATLAS detector, Nikhef and others are designing and building, among other things, a new internal detector, the ITK. Its assembly takes place in a special cleanroom in Amsterdam. Further upgrades have already been made for ALICE and LHCb, partly with new sensor and data technology.

The arrival of the HL-LHC also requires heavier and faster data connections from CERN to data centers elsewhere. To this end, Nikhef has been conducting tests with ultra-fast data connections for quite some time, sometimes the fastest in the world over such distances.