Tag Archives: LHC

What happened to the LHC?

Update: The last of the replacement magnets are now underground.

Update: CERN have released another update about the damage. It uses phrases like “internal splice resistance of 100 nano-ohms” and “It has also been a good week for cryostating in SMI2” so it’s really only for those who are particularly interested.

Update: The first images of the damage caused have been released.

The first image shows a magnet that has wrenched itself free from its mountings and the second shows an example of the damage caused when the magnets shifted relative to each other.

Update: CERN’s analysis of the incident is now on-line.

You may have heard that there are problems at CERN and that the Large Hadron Collider has been shut down.

What happened?

The proton beam is steered through the LHC tunnel by more than 1000 superconducting electromagnets. In order to produce the very strong magnetic fields needed to steer and focus the proton beams there must be a very high current flowing through the magnets; if the magnets weren’t superconducting then this would be impossible due to the energy loss involved.

Mr Reid with a superconducting dipole magnet at CERN.

It looks like part of the power “bus” that passes current from one magnet to the next a 12 million volt transformer overheated and melted, releasing about 1000kg 2000kg of liquid helium coolant into the LHC tunnel. Without the helium coolant the magnets heated up beyond their critical temperature and stopped being superconducting – they “quenched” – and this caused them to get really hot, really quickly. This is a Very Bad Thing and resulted in the LHC being shut down.

You can monitor the LHC’s current cryogenic status via CERN’s LHC website.

Update: Lyn Evans, head of the LHC project, has talked about the accident at a CERN meeting. The video is online; Evans begins speaking at about the 9 minute mark.

In The Event That You Have Accidentally Swallowed The Higgs Boson

From The Morning News:

1. Do not panic. Resist the urge to induce vomiting. If the Higgs boson gets stuck in your teeth, [it] could turn into pure light.

2. If space and time have inverted within your body, skip to step 10.

4. If you happen to ingest the Higgs boson in Europe, proceed to the CERN laboratory in Geneva. Don’t take the airport tram, take the special bus from Meyrin. Make sure you are carrying no metallic objects, as the Large Hadron Collider’s magnetic field is 100,000 times more powerful than the average planet’s. If you are not in Europe, proceed to your nearest hospital, preferably one with a particle physics ward.

6. If the Higgs boson begins creating mass in your esophagus or stomach before you reach a hospital, you will need to perform an immediate bosonectomy on yourself. Luckily, surgical knowledge is not necessary. Just choose from the array of probable outcomes that will manifest themselves upon your decision to perform surgery, and make the one most favourable to yourself into reality. Be sensible—do not wait for the outcome in which you successfully remove the boson and win the lottery and grow wings.

7. Do you feel protons decaying? Grand Unification may be occurring near your vital organs. However, this may be caused by far less elegant X bosons—the poor man’s Higgs, as it were. We shall not deal with these “country cousins” here. Still, you must not use electroweak force in this situation. You must at least attempt to curb the force of your nuclei to delay Grand Unification. You would be wise to begin a preventive training regimen for your nuclei right away—Fermion My Wayward Son (Bloomsbury, 1996) contains the internationally accepted techniques.

10. If you have skipped from step 2 to 10, and space and time have truly inverted, this step no longer has a coherent numerical value and has become a non-associative factor; in fact, this could be step 1,072 or step 30-17, or a step that only exists in a parallel universe. For any and all steps existing in a parallel universe, follow as directed and add beard.