Scientists to start smashing particles as Big Bang machine glitches sorted...

The Hadron Collider, located underneath Switzerland, has been troubled by technical glitches

The Large Hadron Collider (LHC) is poised to start smashing its first particles together early next week, after glitches with the £3.6 billion “big bang machine” were ironed out by engineers.

While scientists had hoped that the successful creation of the particle accelerator’s first beams last Wednesday would clear the way for trial collisions this week, the timetable has had to be delayed because of power failures affecting its cooling system.

The problems were finally resolved today, however, and the LHC team is planning to resume circulating beams of protons around the 17-mile (27km) ring tonight. The success should now allow the two beams to be fired in opposite directions early next week, and then crashed together inside the LHC’s four vast detectors.

Though the energy of these first collisions will be just 6 per cent of the maximum the LHC will eventually achieve, they will be a critical step forward for the project.

Their results will enable scientists to calibrate and test the detectors, before collisions at about 70 per cent of the accelerator’s capacity begin next month. It is then that the LHC will start to provide data that could prove the existence of the Higgs boson, and answer other enduring questions about the nature of the Universe.

Once the two beams had been inserted into the LHC ring last Wednesday, the next task was to “capture” them so that protons are fired in neat pulses or “bunches”.

One of the beams had been captured by Friday, but work was then interrupted by the loss of electrical transformers that power the cryogenic cooling system. The cryogenics chill the LHC’s superconducting magnets to 1.9C above absolute zero.

Laurent Tavian, head of CERN’s cryogenics group, told The Times today that the faults have now been fixed. Engineers can now proceed with “capturing” the second beam, paving the way for collisions within days.

“The plan is now to capture the second beam, and once both beams are ready and captured we can start to do collisions,” Dr Tavian said. “We should now be able to capture the second beam at the end of this week, so we have two beams circulating at the same time. If all goes well, then next week we could have the first collisions in the machine.”

The first collisions will involve beams with an energy of 0.45 teraelectronvolts (TeV), which previous accelerators have been capable of reaching since the 1980s. The goal is to check that the detectors can observe phenomena that are known to occur at such energies, to ensure they are working properly.

The next goal will be to produce beams with energies of 5TeV, which would smash the 1TeV world record, currently held by the US Tevatron, in Batavia, Illinois. This is scheduled to happen by October 12, in time for the LHC’s formal inauguration ceremony on October 21.

Over the winter, the LHC will be shut down for further fine-tuning. Next year, it will be ramped up to its maximum energy of 7 TeV, to produce results that should shed light on some of the most important and enduring questions in physics.

It is a good bet that the CMS and Atlas detectors will find the Higgs boson, though how long that takes depends on the elusive “God particle’s” mass. A heavier boson would actually be easier to find than a light one, because it would decay into larger particles that are simpler to spot. These detectors could also find evidence for extra dimensions or miniature black holes.

The LHCb detector will make discoveries about the balance between matter and antimatter, while the Alice detector will collide lead ions to investigate a mysterious mixture known as quark-gluon plasma. The most exciting discoveries are not expected to be published before 2010, because of the need to sift so much data and ensure against false positives.