The world’s largest and most powerful particle accelerator, the Large Hadron Collider (LHC), is soon to get a major overhaul after 11 years of operation. The impressive 27 km circular structure is found at CERN, near Geneva, Switzerland, and is located 100 m underground. The function of the LHC is to recreate the energy conditions of the early universe by accelerating subatomic particles close to the speed of light and forcing them to collide, in the hope of understanding more about the cosmos at the most fundamental level. The particles are guided around the accelerator by powerful magnetic fields created by superconducting electromagnets, travelling through two tubes maintained at an ultrahigh vacuum to prevent interference. The electromagnets operate in a superconducting state that requires cooling to around -271°C, allowing them to efficiently conduct electricity without losing energy. The machine itself is a piece of revolutionary engineering. However, despite its remarkable design, the LHC is set to close on the 29th of June, 2026 for the next four years to undergo a huge renovation that will transform it into a High-Luminosity Large Hadron Collider (HiLumi LHC).
The HiLumi LHC project aims to maximise the performance of the LHC by increasing a feature known as luminosity by a factor of ten. Luminosity is a measure of how many collisions occur in an accelerator within a given time. To do this, 1.2 km of the current structure needs to be replaced with new advanced components. This project started in 2011, and CERN received partial funding from the European Commission’s Seventh Framework Programme (FP7). Work began in 2023 on the massive matter machine; however, most of the installation process will be done during the four-year shutdown period. During the shutdown, CERN’s accelerator complex will also be improved, and the ATLAS and CMS experiments will be enhanced, allowing them to handle much higher collision rates. Upgrading the LHC will not only improve global research with regards to particle physics but will also drive innovation in technologies such as superconductors, electronics, computing, and engineering. These developments also have a wider benefit for society, including medical applications, sustainable energy solutions, and training the next generation of scientists and engineers, subsequently furthering fundamental knowledge, which is CERN’s primary mission.
It is predicted that the project will require 1.2 billion Swiss francs (approximately £1.1 billion), and this funding will come from CERN Member and Associate Member States. Many countries all over the world have also contributed to the HiLumi LHC, including the UK. This has attracted attention given the ongoing criticism from British physicists regarding funding pressures on UK research facilities. As the LHC prepares for its next chapter, it is also placing the scientific priorities of the UK under the microscope. In December, UK Research and Innovation declared targeted budget reductions and pauses among several research councils. One of those affected was the Science and Technology Facilities Council (STFS), which at the start of 2026, announced budget cuts of up to 30% over the next few years amongst the UK’s astronomy, particle physics, and nuclear physics communities. These cuts would not only affect research grants but would also put hundreds of jobs at risk.
Understandably, questions have been raised among physicists regarding the feasibility of funding external research while British scientific research faces financial challenges. These financial challenges mainly affect early career researchers, and from a recent survey, a majority of them are considering leaving the UK due to significant funding cuts. On Monday, 15th of June, many big names in UK physics, such as Professor Brian Cox and Dr Rebecca Smethhurst, went to Westminster to confront MPs about the current budget cuts, which are discouraging the next generation of physicists.
Professor Brian Cox stated: “The UK has the expertise, heritage and potential to play a leading role in these transformative technologies, but our ability to do so is threatened by these ill-considered cuts, which appear to have been cooked up in haste in response to vague political messages about focusing on government priorities”.
The UK has been a trailblazer in scientific and technological advancements for centuries, yet some of the greatest institutions in the world are facing challenges due to reduced investment and uncertainty in research funding. Without sustainable investment, the momentum of British research risks slowing, and the next generation of physicists risk being accelerated out of the field.
