The Large Hadron Collider at CERN has restarted delivering physics data to its experiments today, following a two-year pause.
Engineers are waiting for the first stream of new data to start flowing from the underground particle smasher, with high expectations for the future of physics.
The vast machine saw proton beams clattered together at almost double the collision energy of LHC’s first three-year run.
The latest move marks the start of season two at the LHC, which will now run around the clock for the next three years, paving the way for the discovery of new scientific phenomena.
“With the LHC back in the collision-production mode, we celebrate the end of two months of beam commissioning,” said Frédérick Bordry, CERN Director of Accelerators and Technology.
“It is a great accomplishment and a rewarding moment for all of the teams involved in the work performed during the long shutdown of the LHC, in the powering tests and in the beam-commissioning process.”
The particle smasher, operated by CERN, has already carried out test collisions at the energy of 13 trillion electron volts (TeV), up from 8 TeV during the machine’s first run.
Today at 09:40, the LHC operators in Geneva guided two stable beams or proton particles around the machine before smashing them in to one another at preset points along the 27km ring.
Beams are made of 'trains' of proton bunches moving almost at the speed of light and circulate in opposite directions, guided by powerful superconducting magnets.
The LHC was filled with six bunches, each containing around 100 billion protons, a rate that will be progressively increased as the run goes to 2808 bunches per beam, to allow the LHC to produce up to one billion collisions per second.
During the first run of the LHC, the Higgs boson was discovered – the last missing piece of the Standard Model, a theory that explains our physical world and crucially is believed to be responsible for giving mass to all other particles.
The latest increase in energy to the LHC is vital for pushing for further discoveries about the Universe.
“The first three-year run of the LHC, which culminated with a major discovery in July 2012, was only the start of our journey. It is time for new physics,” said Rolf Heuer, CERN Director General.
“We have seen the first data beginning to flow. Let’s see what they will reveal to us about how our universe works.”
The boost to collisions at 13 TeV had been made possible after an extensive two-year programme of repairs and upgrades, including the re-joining of thousands of connections between the LHC’s superconducting magnets after flaws were found.
“The collisions we are seeing today indicate that the work we have done in the past two years to prepare and improve our detector has been successful and marks the beginning of a new era of exploration of the secrets of nature,” said Tiziano Camporesi, CMS spokesperson.