Accelerator Report: 10 000 LHC fills!

Each LHC machine cycle is assigned a “fill number” to identify it uniquely. This fill number goes up by one for every new LHC cycle. Fill number 1 was attributed to a machine test cycle back in 2007. When the first protons were injected into LHC ring 1 on the evening of 8 August 2008 (just after 8 p.m. on 08/08/08), the fill number had already increased to 818 as a result of the numerous dry tests performed in preparation for the first beams.

On 13 August 2024, the LHC reached fill number 10 000. Unfortunately, fill 10 000 will not be remembered for any other records because it produced collisions for only 4 hours before a disturbance on the electrical network triggered the beam dump.

Of those 10 000 fills, 1816 between May 2010 and today are associated with proton physics fills, i.e. when the mode is switched to stable beams for data taking by the LHC experiments. 223 other fills correspond to ion physics fills, mainly for lead–lead or proton–lead collisions. Physics fills account for only one fifth of the total number: the other fill numbers are associated with dry test cycles, machine commissioning, machine experiments and repeated injection phases.