Highest energy ever

At this very moment the LHC is busy trying to set a new world record. The goal is to achieve beams circulating at 3.5 TeV, bringing collisions between protons to 3.5+3.5=7 TeV center-of-mass energy. This would be the highest particle energy ever accomplished by humans (nature somehow routinely manages to produce cosmic rays at energies 8 orders of magnitude higher!). This news is hot off the press: we had a talk today by Lyn Evans, and he gave us the latest update. He should know what’s going on, since he’s project leader of the LHC. Evans shared some entertaining anecdotes from the last few years of commissioning, including:
They use superfluid helium to cool the superconducting magnets. One of the many weird properties of this stuff is that it has zero viscosity. Which means that, if there’s any sort of hairline fracture anywhere in the 27 kilometer long tunnel, the stuff comes spewing out, and very, very bad things happen. Every component, every joint, every one of the tens of thousands of tiny connections has to be perfect. It is this sort of failure which brought the machine to its knees shortly after commissioning, over a year ago.
The ...