The Large Hadron Collider (LHC) will start smashing its first protons in October and run through the winter to keep it ahead in the international race to find the elusive “God particle”.

The CERN laboratory’s decision to operate the £4 billion particle accelerator all year round makes it unlikely that the LHC will be beaten to the discovery of the Higgs boson, even after a serious fault forced a year-long shutdown, Lyn Evans, the project’s leader, told The Times.

The delay has raised the prospect that the Tevatron, a less powerful accelerator at Fermilab in Illinois, might be first to find the particle that is believed to give matter its mass. It has recently narrowed down the search and its scientists hope that they might find hints of the boson next year.

The decision to keep the LHC open over the winter, when atom smashers are usually closed down to avoid peak electricity charges, will make up for lost time and put CERN back in pole position, Dr Evans said. “This will give us a shot much earlier,” he said at The Times Cheltenham Science Festival . “I always wish Fermilab good luck, but they will have a hard job now. I’ve no doubt that they will publish more limits for the Higgs, but it’s going to be very hard for them to go much further. That’s a job for the LHC.”

Winter operations, which will cost CERN £13 million, mean physicists will be able to start working on LHC data even if there are further delays. “It would have been terrible if we’d got everything working and then had to shut it down straight away. So we’ve decided to bite the bullet and keep it going. That means if the schedule slips by a week or two, it’s not so bad. Up until this year that was inconceivable.”

The Tevatron and other accelerators have established that the Higgs cannot have a mass greater than 185 gigaelectronvolts (GeV) or lower than 114GeV, and Fermilab announced results in March that rule out values between 160 and 170GeV. Only if the Higgs has a mass in certain parts of the range will the Tevatron be able to find it.

Dr Evans said: “It’s possible they might get a hint of it, but there’s a big difference between a hint and a discovery.”

The LHC “big bang machine”, near Geneva, is being readied for its restart after repairs to the catastrophic fault that shut it down just days after it was switched on last year. The first beams of particles will be fired around its 17-mile (27km) ring in September and the first collisions will follow about a month later, Dr Evans said.

Magnets that will guide particle beams around four of the LHC’s eight sectors have already been cooled to their working temperature of 1.8C above absolute zero (minus 271.3C), and the entire ring will have been chilled by the end of August, Dr Evans said.

“Half the machine is cold and we’ll soon be cooling the other four octaves,” he said.

The breakdown and repairs, Dr Evans said, will be quickly forgotten once the LHC starts providing exciting new insights into the nature of the Universe. “I remind you that the Hubble Space Telescope also hit a problem which was fixed and it’s had a marvellous experience since then,” he said. “We’ll come back in October or November and then we’ll be going for a long time.”

The atom smasher, which will fire particle beams against one another at 99.9999991 per cent of the speed of light, has been fitted with a range of new security features to guard against a fresh fault and to limit the damage should one occur.

Nine days after the LHC was activated — to global acclaim — on September 10 last year, a connection between two magnets failed, causing a huge leak of the helium that cools the ring. This inflicted further damage and the accelerator had to be warmed up and mothballed so that 53 magnets could be replaced. Engineers have since found and replaced two other magnet connections that could have been at risk of causing a repeat of the fault. The magnet network has also been fitted with pressure release valves, so that a problem with one will not cause damage to its neighbours, and an early-warning system has been installed to alert operators to potentially dangerous temperatures rises of as little as 0.01C.

“The important things were to make sure that it doesn’t happen again, and to make sure that, if it does, the collateral damage is contained,” Dr Evans said. “We now believe the entire machine is clean.” Last year’s fault, he said, happened in the only one of the eight sectors that had not been tested at high energy before the LHC was switched on. “It was only by going back through the data that we see a signal that was considered insignificant at the time. A helium valve was opening and that’s because the fault was drawing more and more helium to keep things cool, until it couldn’t any more. The safety system was not good enough to cope.”

The successful experience of threading the accelerator’s beam around the ring will stand the LHC in good stead for the restart. “All the corrections we need to make are now known, so we know what to do,” Dr Evans said.

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