The High-Luminosity Large Hadron Collider (HiLumi LHC) project aims to transform the LHC in order to increase the potential for discoveries after 2030. The objective is to maximise the performance of the LHC by increasing its integrated luminosity by a factor of 10 compared to its original design value.
Luminosity is an important indicator of the performance of an accelerator: it is proportional to the number of collisions that occur in a given amount of time. The higher the luminosity, the more data the experiments can gather to allow them to observe rare processes.
The HiLumi LHC, which should be operational in mid-2030, will allow physicists to study known mechanisms in greater detail, such as the Higgs boson, and observe rare new phenomena that might reveal themselves.
Its development requires replacing 1.2 kilometres of the LHC with completely innovative components. The first phase of the project began in 2011 and was partly financed by the European Commission’s seventh framework programme (FP7). The construction phase for the project then began at CERN, as well as in industry and at collaborating institutes in 2015. Civil engineering work began in 2018 and the installation in 2023. However, most of the installation will take place during a long shutdown period of the accelerators, beginning in mid-2026. This shutdown will also be used to upgrade CERN’s accelerator complex as well as to completely transform the two general-purpose experiments, ATLAS and CMS, to prepare them for the staggering number of collisions.
The HiLumi LHC project is led by CERN with the support of an international collaboration of nearly 50 institutions in over 20 countries – the vast majority located in Europe. In addition to the funding provided by CERN Member States and Associate Member States, the project received special contributions from Italy, Spain, Sweden, the United Kingdom, Serbia and Pakistan, and from several non-Member States such as the United States, Japan, Canada and China.