'Big Bang' machine to be ready by summer

The £4bn "Big Bang" machine, which suffered a catastrophic malfunction soon after being switched on last September, is expected to be restarted in June.

The Large Hadron Collider suffered a catastrophic malfunction soon after being switched on amid a fanfare of publicity last September.

A faulty electrical connection led to a leak of super-cold helium causing damage estimated at £20 million.

As a result, 53 of the magnets used to accelerate sub-atomic particles around the machine's 17-mile underground tunnel have had to be brought to the surface for repair or cleaning.

Engineers have now designed fail-safe protection systems to ensure that a similar accident never happens again.

Electronic monitors will provide early warnings of hazards, and the magnet network will also be fitted with pressure-release valves to confine the damage caused by any future leak.

The LHC, the biggest atom-smashing machine ever built, straddles the borders of France and Switzerland and is operated by Cern, the European particle physics laboratory near Geneva.

It is designed to simulate the "Big Bang", which started the universe 15 billion years ago, by smashing sub-atomic particles together at energies never before achieved.

Scientists hope this will help them find the answers to big questions, such as what causes mass and whether hidden dimensions exist in space.

There is also a possibility of tiny black holes being created in the Collider. Experts insist that if this happens, they will pose no threat.

LHC project leader Lyn Evans said: "We have a lot of work to do over the coming months, but we now have the roadmap, the time and the competence necessary to be ready for physics by summer. We are currently in a scheduled annual shutdown until May, so we're hopeful that not too much time will be lost."

The total cost of repairing and refitting the machine is likely to exceed £30 million.