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The Large Hadron Collider at Cern in Geneva has been fired up for the first time since its high-profile failure last year. The huge particle accelerator successfully powered some protons and lead ions around short sections of its 17-mile ring on Friday, and everything seemed to be working correctly.
Engineers and scientists have been warily putting it through its paces for the first time since its catastrophic breakdown, or “quench”, which happened when two of the LHC’s huge superconducting magnets suffered a short circuit within days of it powering up. The problem ripped the two magnets from their moorings and caused the loss of over a ton of liquid helium coolant, putting the accelerator – the largest ever built – out of use for over a year.
After months of painstaking work, however, the system has been repaired, and the magnets cooled down to just 1.9 degrees above absolute zero (or -456 Farenheit), colder than interstellar space.
Before the LHC can fire up in earnest, however, it needs to be carefully tested, to prevent a similar failure.
The beams of protons and lead ions were fired clockwise through the section of the ring housing the “A Large Ion Collider Experiment” (ALICE) detector, before protons alone were fired anticlockwise through the LHCb detector.
The painstaking approach is necessary, say engineers, because of the infinitesimal calibrations required to make it work correctly.
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