Scientists today carried out a “heart transplant” on the Large Hadron Collider – world’s largest and most powerful particle accelerator – by replacing a key component inside one of its experiments.
The new pixel detector was installed in a complex and delicate procedure 100 metres underground. The first major upgrade to the LHC may boost the hunt for new sub-atomic particles.
The LHC is a particle accelerator that pushes two particle beams to near the speed of light and smashes them together so that scientists can look for signs of new physics phenomena in the debris – including new sub-atomic particles.
More than 1,200 dipole magnets steer the beam around a 27 kilometres-long circular tunnel under the French-Swiss border. At certain points around the ring, the beams cross, allowing collisions to take place. Large experiments then record the outcomes of these encounters, generating more than 10 million gigabytes of data every year.
The CMS (Compact Muon Solenoid) pixel detector is designed to disentangle and reconstruct the paths of particles emerging from the collision wreckage. “It’s like substituting a 66 megapixel camera for a 124 megapixel camera,” Austin Ball, technical co-ordinator for the CMS experiment, told ‘BBC News’.
CMS and its counterpart Atlas are the two “multi-purpose” experiments at the LHC. Staffed by separate teams of physicists, they provided the crucial evidence that led to the discovery of the elusive Higgs boson, announced in 2012. The Higgs was the last major jigsaw piece in the theory of particle physics known as the Standard Model (SM).
But the hoped-for signs of physical phenomena beyond the Standard Model, such as evidence for dark matter or supersymmetry – a theorised extension to the SM which invokes a range of new sub-atomic particles – have taken longer than expected to reveal themselves at the LHC. The change to CMS should help physicists in that endeavour, said Ball.