Dig, dig, dig. One hundred metres underground, excavation work is under way for the High-Luminosity Large Hadron Collider project. This next-generation LHC, which will begin operation in 2026, will reach luminosities five to ten times higher than its predecessor. This increased number of collisions will increase the chances of observing rare processes.

The worksites are Point 1 of the LHC in Meyrin (Switzerland), where the ATLAS experiment is located, and Point 5 in Cessy (France), which houses the CMS experiment. Following the excavation of two shafts around sixty metres deep in January, two underground halls and over a kilometre of technical galleries must now be dug. 

At the surface, ten buildings, five on each site, will be built in the coming months, to house electrical, ventilation and cooling equipment. The work began in 2018 and should be completed in 2022.