Low-energy collisions at the LHC

For the first time since the restart of the Large Hadron Collider – the world’s largest and most powerful particle accelerator – low-energy proton collisions have been delivered.

Following two years of maintenance and repairs the Large Hadron Collider (LHC) – run by CERN – delivered proton-proton collisions at energy of 450 gigaelectronvolts per beam to the experiments ALICE, ATLAS, CMS and LHCb.

These collisions – which take place with each beam at an energy level known as injection energy – will enable scientists to tune the LHC detectors. This process will prepare the accelerator to deliver beams at 6.5 teraelectronvolts (TeV) for collisions at 13 TeV.

The LHC team is testing each system, component and algorithm to confirm that everything is fully functional when collisions are delivered at 13 TeV. Meanwhile, the operations team is now halfway through its eight week scheduled beam commissioning work to ensure that beams circulate in a stable way and in the correct orbit.

Before the full physics programme begins, the LHC operations team will check the beam orbit, quality and stability at 13 TeV.