The Large Hadron Collider (LHC), the world’s most powerful atom smasher, was switched off on Monday night ahead of major upgrades.
After running one last experiment, the particle accelerator has now entered a four-year-long shutdown period.
But the LHC won’t be gone for good, as scientists say it will return in its most powerful form ever.
The collider is expected to fire up again in 2030, having been upgraded to become the High-Luminosity LHC (HiLumi LHC).
This long shutdown period is all in service of increasing the collider’s ‘luminosity’, or how many particle collisions it creates per second in a given area.
Once the upgrade is complete, CERN expects the HiLumi LHC to have 10 times more luminosity and allow scientists to collect around 100 times more data.
The total cost of the upgrade is expected to come in around $1.5 billion (£1.29 bn), paid for by CERN membership fees and in-kind contributions from the US, Japan, Canada, and China.
However, despite the astronomical price tag, scientists believe this investment is key to uncovering the universe’s most fundamental secrets.
The Large Hadron Collider (LHC), the world’s most powerful atom smasher, was switched off on Monday night ahead of major upgrades
The LHC works by accelerating ‘bunches’ of protons around a 16.7-mile (27 km) loop of electromagnets until they reach absurd speeds, and smashing them into one another.
Incredibly sensitive detectors then sort through the wreckage to see what strange and exciting subatomic particles briefly appear.
Over three operational runs, the collider has given scientists an unprecedented view of the fundamental reality of the universe.
Most famously, in 2012, scientists announced the discovery of the so-called ‘God Particle’ or Higgs Boson – the subatomic particle that gives other particles their mass.
The LHC started running in September 2008, and successfully smashed its first protons together in 2009.
However, it is now time for the old version of the collider to retire, and a new one to emerge in its place.
Oliver Brüning, CERN Director for Accelerators and Technology, says: ‘The LHC has exceeded every expectation.
‘For nearly two decades, it has transformed our understanding of the Universe and inspired generations of scientists, engineers and citizens around the world.
The LHC will now be upgraded to the High Luminosity LHC, which could gather up to 100 times more data about fundamental physics
‘Today we say goodbye to the LHC as we have known it, while preparing to welcome its successor: the HiLumi LHC.’
Upgrading the LHC will be no small feat, with over 0.75 miles (1.2 km) of magnets needing to be replaced within the collider tunnels alone.
The new HiLumi LHC will be so much more powerful than its predecessor that almost the entire infrastructure surrounding the collider needs upgrading.
Because the luminosity is much higher, the LHC will create between 140 and 200 proton collisions every time a bunch of particles cross – up from just 60.
That will produce more than five billion collisions per second, creating so much data that it will be physically impossible to store everything.
Instead, the new LHC will have to rely on massively upgraded detectors equipped with AI systems that automatically decide which events are interesting enough to keep.
Jean-Philippe Tock, Head of the LS3 Coordination Team, says: ‘The LS3 represents a huge and complex logistical and engineering undertaking.
‘Components will be removed and replaced with new equipment, and across the whole complex, dozens of projects are planned, involving thousands of engineers, physicists, technicians and support personnel.’
These upgrades are expected to cost around $1.5 billion (£1.29 bn). The newly improved LHC will gradually start operations in 2028 and start creating collisions around 2030
The HiLumi LHC won’t start gradually restarting until at least 2028, and the first collisions aren’t expected until 2030.
In the meantime, thousands of researchers will keep busy poring over the vast data sets collected in the LHC’s first three runs.
However, once testing begins, scientists are hopeful that the collider could crack some of the toughest questions in science.
With a much greater luminosity, the atom smasher could help illuminate the secrets of the subatomic world, antimatter, and the first few seconds of the Universe.
Most importantly, researchers want to probe and find new particles that could help explain the balance between matter, dark matter, and dark energy.
Scientists think that ordinary matter, such as dust, stars, and our bodies, only makes up about five per cent of the mass of the universe.
The rest is composed of invisible materials known as dark matter and energy, with dark matter making up around 27 per cent and dark energy contributing the remaining 68 per cent.
Discovering the Higgs Boson was one step towards unravelling this mystery since it helped explain why any of this matter has mass in the first place, but there is still so much scientists don’t know.
Over 0.75 miles (1.2 km) of magnets need to be replaced within the collider tunnels alone, and the site’s infrastructure will need major changes to handle the more powerful collider
A CERN representative told the Daily Mail: ‘HiLumi upgrade will allow researchers to collect vastly larger datasets, measure the Higgs boson in much greater detail, study extremely rare processes and increase the chances of spotting signs of new physics beyond the Standard Model.
‘Over its lifetime it could produce about 380 million Higgs bosons, compared with roughly 55 million Higgs bosons produced since the start of the LHC.’
According to Dr Nedaa-Alexandra Asbah, a research physicist at CERN’s ATLAS experiment, the real dream would be to create two Higgs bosons at once and see them interact.
Dr Asbah says this may ‘provide clues about how our universe evolved shortly after the Big Bang’.
WHAT IS THE LARGE HADRON COLLIDER?
The Large Hadron Collider (LHC) is the world’s largest and most powerful particle accelerator.
It is located in a 27-kilometer (16.8-mile) tunnel beneath the Swiss-French border.
The LHC started colliding particles in 2010. Inside the 27-km LHC ring, bunches of protons travel at almost the speed of light and collide at four interaction points.
Inside the accelerator, two high-energy particle beams travel at close to the speed of light before they are made to collide. The beams travel in opposite directions in separate beam pipes.
They are guided around the accelerator ring by a strong magnetic field maintained by superconducting electromagnets.
The LHC (pictured) was restarted on April 5th 2015, having been turned off for two years during a major renovation project that cost £100 million
The electromagnets are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy.
These collisions generate new particles, which are measured by detectors surrounding the interaction points.
A view of the LHC’s Compact Muon Solenoid experiment is shown
By analysing these collisions, physicists from all over the world are deepening our understanding of the laws of nature.
While the LHC is able to produce up to 1 billion proton-proton collisions per second, the HL-LHC will increase this number, referred to by physicists as ‘luminosity’, by a factor of between five and seven, allowing about 10 times more data to be accumulated between 2026 and 2036.
This means that physicists will be able to investigate rare phenomena and make more accurate measurements.
For example, the LHC allowed physicists to unearth the Higgs boson in 2012, thereby making great progress in understanding how particles acquire their mass. The subatomic particle had long been theorised but wasn’t confirmed until 2013.
