Little bang knocks out Large Hadron Collider

19 Sep 2008

A 30-tonne power transformer that helps run the massive Large Hadron Collider (LHC) at CERN on the French-Swiss border has malfunctioned, affecting the cooling system on the world’s largest scientific experiment which aims to recreate the Big Bang.

The LHC is a giant machine that traverses a 27-kilometre tunnel between France and Switzerland around which particles will zoom at almost the speed of light before colliding, recreating the events after the Big Bang that produced our universe and life as we know it.

From 300 feet underground, the massive LHC will slam together particles to find the elusive Higgs Boson, or ‘God Particle’.

The US$8.3bn project attracted condemnations from quacks around the world, who predicted a black hole would be created that could eventually suck in the Earth and end the planet.

In a progress report on the first week since the LHC went live, scientists at CERN have described it as a “mixed first week.”

They said that to get the beams around the ring in both directions on the first day exceeded all expectations, and the success continued through the night, with several hundred orbits being achieved.

The next step in the commissioning process was to bring in the radio-frequency (RF) system that keeps the beams bunched, rather than spreading out around the ring, and this will eventually accelerate them to 7 TeV.

The RF system works by ‘capturing’ the beam, speeding up the slower-moving particles and slowing down the faster ones so that the beam remains bunched into fine threads about 11 cm long. Without it, the beam quickly dissipates and cannot be used for physics.

On Thursday, 11 September, beam two – the anti-clockwise beam – was captured and circulated for over half an hour before being safely extracted from the LHC. The next step is to repeat the process for beam one, and that is set to begin this week.

However, the unexpected can occur for even the best-funded and largest concentration of scientists in the world.

The scientists said the past week has been spent recovering cryogenic conditions after the failure of a power transformer on one of the surface points of the LHC, which switched off the main compressors of the cryogenics for two sectors of the machine.

According to CERN: “The transformer, weighing 30 tonnes and with a rating of 12 MVA, was exchanged over the weekend. During this process, the cryogenics system was put into a standby mode with the two sectors kept at around 4.5K.

“Since the beginning of the week the cryogenics team have been busy re-cooling the magnets and preparing for operation with beam, which is currently forecast for today. The next stage of the commissioning will be single-turn studies using beam one, followed by RF capture and circulating beam in both rings.”

Scientists at CERN say they are confident the LHC is still on course for first collisions in a matter of weeks.

By John Kennedy

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years