View of the CMS detector in the surface hall at Cessy. Image via CERN

After a 2 year hiatus for updates, the LHC was set to resume work this month. Many were looking forward to the restart, when we would hopefully get some long sought answers to the mysteries of dark matter (and maybe even some clues about extra dimensions). With the new updates, the LHC is twice as powerful. And it was ready to start probing into antimatter, extra dimensions, and exotic particles that might only be exposed through interaction with the Higgs field.

However, scientists encountered some problems. Unfortunately, a it seems that little piece of metal that fell into the system, which created a short circuit in the LHC. And how do you deal with such an event in a 17-mile-round (27-kilometer-round) ring of helium-cooled magnets?

It seems that you just, well, melt the issue.

In a recent status update from CERN,  engineers assert that the glitch is likely due to some scrap metal that made contact with a cable that connects a dipole magnets with a diode box. Yet, the tests, thus far, have not been entirely helpful. In fact, they haven't been helpful at all, really. X-ray scans of the wiring around the suspected fault have been inconclusive. However, CERN is not totally in the dark. They report that measurements that were taken by system experts were able to trace the fault to within 10 cm (which is a pretty small area).

This was accomplished by injecting current locally and using the standard cold mass instrumentation. From here, they have a few different options. Enter (what seems to be the easiest of the proposed scenarios) melting.

Engineers Aline Piguiet and Markus Albert take X-rays of the shorted superconducting dipole in sector 3-4 in the LHC tunnel (Image: Maximilien Brice/CERN)

The operations team is now exploring three main options to fix the short: inject a controlled pulse of current to try to melt the offending object; try to dislodge the object by altering the flow of helium in that region; partially warm up the sector and open the magnet interconnect concerned. Though the third option would allow direct access to the diode box, the warm-up, intervention and subsequent cool-down would take around six weeks.

That said, a full evaluation of the situation is still ongoing. For those of you who want more technical details, you can get them here.


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