The High-Luminosity LHC

The High-Luminosity Large Hadron Collider (HL-LHC) project aims to crank up the performance of the LHC in order to increase the potential for discoveries after 2025. The objective is to increase luminosity by a factor of 10 beyond the LHC’s 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 High-Luminosity LHC, which should be operational by 2025, will allow precise studies of the new particles observed at the LHC, such as the Higgs boson. It will allow the observation of rare processes that are inaccessible at the LHC’s current sensitivity level. For example, the High-Luminosity LHC will produce up to 15 million Higgs bosons per year, compared to the 1.2 million produced in 2011 and 2012.

The High-Luminosity LHC project was announced as the top priority of the European Strategy for Particle Physics in 2013 and its funding is enshrined in CERN’s Medium-Term Plan.

Its development depends on several technological innovations.  The first phase of the project began in 2011 with the “HiLumi LHC” design study, which was partly financed by the European Commission’s seventh framework programme (FP7). This first phase brought together many laboratories from CERN’s Member States, as well as from Russia, Japan and the US. The institutes in the US took part in the project thanks to the support of LARP (US LHC Accelerator Research Program), funded by the US Department of Energy.

The design study came to a close on 31 October 2015 with the publication of a technical design report, marking the start of the construction phase for the project at CERN and in industry.

CERN will devote 950 million CHF of its budget over a period of 10 years to the development of the High-Luminosity LHC.

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Featured updates on this topic

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29 Mar 2017 – CMS high-luminosity LHC upgrade requires new silicon sensors, to better distinguish between particles from multiple collisions

14 Nov 2016 – After having accelerated a beam up to the design energy of 160 MeV, Linac 4 is now entering a new phase of its commissioning


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22 Apr 2018 – After several years of preparatory work, the first crab cavity prototypes have been installed in the SPS tunnel and are ready for testing

5 Mar 2018 – The world’s first Big Science Business Forum gathered 18 of the most advanced big-science organisations together to meet European companies

21 Feb 2018 – The LHC shows its teeth each time protons misbehave

5 Dec 2017 – Before the LHC was shut down for the winter, the operators tested techniques under development for its successor, the High-Luminosity LHC (HL-LHC)

23 Jun 2017 – New magnets designed for the High-Luminosity LHC - the Large Hadron Collider upgrade project – are in the prototype phase

18 Jul 2016 – A new tool for building superconducting magnet coils for High-Luminosity LHC and future particle accelerators arrives at CERN

17 Dec 2015 – In preparation for civil engineering work for the High-Luminosity Large Hadron Collider, vibration measurements have been carried out near the LHC

27 Nov 2015 – CERN test magnet reaches a record-breaking goal of 16.2 tesla field, paving way for future accelerator designs

27 Oct 2015 – Meeting of scientists and engineers from around the world marks end of design phase for High-Luminosity project to upgrade the Large Hadron Collider