The world's largest particle accelerator has performed its first collisions, and its first beam acceleration.
Progress on the giant experiment has been rapid in the four days since the Large Hadron Collider (LHC) was restarted, Cern director of communications James Gillies told ZDNet UK on Tuesday.
"These collisions are the first in the LHC at all," said Gillies. "We've been going into new territory. It's been going quite remarkably fast."
Gillies told ZDNet UK that not only had scientists recorded the first collisions of protons on Monday, but that overnight one of the beams had been accelerated.
"This was the first acceleration in the LHC," said Gillies. "It's nice to know the LHC is able to work as a particle accelerator."
On Monday night, the beam was accelerated from its initial injection energy of 450 giga-electron-volts (GeV) up to 540 GeV, said Gillies. This followed recorded collisions on Monday.
Cern said in a press statement on Monday that the LHC had circulated two beams simultaneously so operators could test the synchronisation of the beams. These tests were successful, said the statement. "With just one bunch of particles circulating in each direction, the beams can be made to cross in up to two places in the ring," it said. "From early in the afternoon, the beams were made to cross at points 1 and 5, home to the ATLAS and CMS detectors, both of which were on the look-out for collisions. Later, beams crossed at points 2 and 8, ALICE and LHCb."
The spokesperson for LHCb, Andrei Golutvin, said in the statement: "The tracks we're seeing are beautiful. We're all ready for serious data taking in a few days time."
Cern does not expect any new physics to come out of the initial beam collisions, as the beam intensity is not yet powerful enough, said Gillies. The accelerator was off on Tuesday so engineers could tweak the equipment, Gillies added. In the meantime, Cern physicists are analysing results.
In the run-up to Christmas, the beams will be tested at increasing intensities, with the aim of reaching 1.2 tera-electron-volts before the break, said Gillies. Beam collisions will be performed for calibration work, said Gillies, while a programme of systematic measurements of LHC will take place over ten days before Christmas.
The LHC was restarted on Friday after a hiatus of over a year. The giant experiment had to be shut down nine days after it became operational last September, following an explosion caused by a faulty copper splice.
