…when under the influence of extremely high magnetic fields, there is physical motion in the magnet’s wire, leading to friction. The friction generates local heat which transitions a small amount of wire from superconducting to “normal”. The magnets carry such immense currents that the small resistance of the normal wire turns into a large amount of local heat; this in turn *transitions more wires* from superconducting to normal; and the process spreads. It all happens fast, with the risk of explosion.
— Vern Paxson, explaining the risk of explosion in superconducting magnets used in particle physics like the Large Hadron Collider. The LHC will start again in December.
