LHC halted for 2 months

After last week’s transformer failure, a new hardware malfunction has stopped the LHC dead in its tracks. This time, the electrical link between two of the particle accelerator’s massive 30-ton superconducting magnets has failed, causing a magnet quench event. Due to having to warm up the section of the tunnel containing the magnet in order to conduct repairs, and then cool it back down to its -271°C operating temperature, these repairs will take at least two months.

Technical setbacks have plagued the Large Hadron Collider ever since it was started on September the 10th, including a transformer failure which shut down its cooling plant, which was only repaired on Thursday. Immediately afterwards, on Friday, during a test, one of the bus bar connections which linked cables between the magnets failed, and melted thus causing roughly a ton of liquid helium to leak into one of the tunnel sections. The fire brigade had to be called to handle the situation. "It seems to be a badly made connection – but this all has to be confirmed once we have had the chance to take a look at it," said James Gillies, director of communications at CERN.

The rather large dipole magnets that are used to steer protons around the Large Hadron Collider’s circular tract, are superconductive. What this means is that scientists have taken advantage of a property of matter by which its electrical resistance is lowered to naught when cooled very close to absolute zero. This allows much more current to be passed through the magnets, giving them much more force in steering the supercharged particles, which can run at up to 7 terra-electron-volts.

Non-superconductive magnets simply would not be strong enough to handle the proton beams, which would steer off-track, hitting the collider pipe walls. These particles, at such energy levels, can melt through several feet of steel in nanoseconds, so you don’t want those out of control.

Getting the magnets to and out of such low temperatures however – colder than outer space – takes a while however, and were it not required to use superconducting magnets, the repairs would only take a few days. This way, it will at least take two months, dangerously narrowing the window of opportunity in which to conduct the collision tests. This is because the LHC facility shuts down during the winter to save on energy costs. If they don’t get the problem fixed by then, there won’t be any collision until 2009.

CERN physicists are not very worried though, and are calling this an expected setback as the LHC, which is arguably the most complex machine ever built, has been in construction for 20 years and has so far cost more than $8 billion, and such hitches have been very probable since the beginning.

"If you keep an eye on the big picture, we've been building the machine for 20 years. The switch-on was always going to be a long process," said Gillies, who went on to say that "A year or two down the line, this moment will be a distant memory, and we'll be running smoothly."

The LHC’s Gala Inauguration party, set for October 21, will still take place, according to Dr. Gillies.