Well, it’s hit Slashdot now, so it won’t take long to make the rounds. The Large Hadron Collider project at CERN suffered something of a setback on Tuesday, when, during a test of one of the quadrupole magnets, which focus the beams down to tiny size at the collision regions, the magnet failed catastrophically. Though saying it like that sounds bad, here is a photo:
The failure occured during a test which simulated what the magnet might experience during a “quench” which is when some part of the superconducting cable inside the magnet suddenly goes “normal” and then resists the flow of the huge current in it. This releases heat, of course, causing the rest of the superconducting material to go normal. Liquid helium boils rapidly, creating large asymmetric pressures inside the magnet cryostat. These pressures can reach 20 bar, and it was during a 20-bar test that this particular magnet failed. No one was in the LHC tunnel when it happened – it must have been quite a sight, and sound, though.
I heard about this on Thursday, as did many of my colleagues, and we waited with trepidataion to hear how bad a problem this was. Yesterday at Fermilab, Steve Holmes, an accelerator physicist, gave a talk at our weekly US CMS meeting, and sounded confident that a solution could be found quickly to the design flaw which gave rise to the problem. The magnets were designed and built at Fermilab, and delivered to CERN and installed last year. CERN is leading the effort to find and implement a fix, with Fermilab’s help. Personally, I have little doubt that these world experts will solve this thing rapidly, and hopefully it won’t affect the LHC schedule much, and perhaps not at all.
You can get more details in Fermilab’s statement.