A giant magnet is placed underground in the Large Hadron Collider (LHC) at CERN, the European Particle Physics laboratory, on Feb. 28. A set of smaller magnets failed a pressure test on March 27, potentially delaying the collidor's activation. ((Salvatore Di Nolfi/Associated Press))

A key component to the world's largest particle collider failed during a test last week, officials from the U.S. and Europe said Tuesday.

A 13-metre-long magnet, designed to accelerate protons to great speeds, broke on March 27 "with a loud bang and a cloud of dust" during a high-pressure test, officials from Illinois-based Fermilab and the European Organization for Nuclear Research, or CERN.

The magnet was one of a set of three Fermilab manufactured and installed for use at CERN's Large Hadron Collider, a massive particle accelerator and collider that was expected to turn on in November 2007 and be fully functional by 2008.

"It's impossible really to say whether that [schedule] can be maintained at this stage," said James Gillies, spokesman for CERN.

The LHC β€” which runs for 27 kilometres underground beneath the Franco-Swiss border β€”is expected to be the most powerful tool yet for physicists hoping to uncover the secrets behind the laws of the universe, both on the tiny scale of quantum mechanics and the huge areas affected by galaxies and black holes.

The accelerator will push two proton beams through its 27-kilometre-long tunnel at speeds and energies never before reached and collide them into one another to create and detect a host of new particles.

LHC speeds the protons through a series of superconducting magnets, each of which push them through the pipe and impart greater and greater amounts of energy. The protons are then smashed into each other, causing them to break apart into other particles. The higher the energy of the accelerator, the more likely the protons will transform into completely different particles.

The Fermilab-manufactured magnets were designed to focus the protons travelling down one track before they collided with the protons travelling in the opposite direction.

To ensure the magnets transfer as much energy as possible, they are kept at extreme cold temperatures by a surrounding layer of liquid helium. Energy built up in this layer of helium is occasionally released during the operation of the machine, resulting in increased pressure on the magnets. So after assembly of the collider, the magnets were exposed to pressure tests last week.

Fermilab blamed the failure on a support holding the magnet which came apart after it was exposed to 20 times normal atmospheric pressure.

A design flaw in the support of all three magnets means the whole set will have to be replaced.

"We took a pratfall on the world stage," said Pier Oddone, director of Fermilab, which has its own, smaller collider at Batavia, Ill. "We are dumbfounded that we missed some very simple balance of forces."

More than 2,000 researchers will be working at the LHC to interpret the results of its particle collisions.

The detection or lack of detection of these particles could provide evidence that backs up or disproves current theories of the universe.

With files from the Associated Press