The LHC leak repair: a short photostory

At 1 a.m. on Monday, 17 July, the LHC beams were dumped due to an electrical perturbation. Approximately 300 milliseconds later, several magnets lost their superconducting state ("quenched"). During a quench, the magnet warms up, which in turn warms and pressurizes the liquid helium that surrounds it.

While not common, this sequence of events is expected to happen to protect the superconducting cable of the magnet when an electrical glitch occurs; the mechanical stress exerted on different parts of the magnet can be quite strong.

Among the magnets that quenched on 17 July were the inner triplet magnets located to the left of Point 8 of the LHC, which play a crucial role in focusing the beams for the LHCb experiment. Unfortunately, this time, the quenches led to a helium leak in these magnets and stopped regular LHC operations.

Scroll through the photo diary below to re-live the ten day race against the clock to successfully repair the leak.