Repair work to the world's biggest particle collider may take until early summer and cost at least 25 million Swiss francs, or $25.6 million Cdn, its operator said Monday.

Fixing an electrical failure that shut down the Large Hadron Collider in September is likely to take longer than initial estimates, according to a spokesman for the European Organization for Nuclear Research, known by the French acronym CERN.

Spokesman James Gillies is now estimating the restart of the massive physics experiment will be at the end of June or later.

"If we can do it sooner, all well and good. But I think we can do it realistically (in) early summer," he said.

The collider, which lies in an underground facility near Geneva, Switzerland, is designed to push protons, using a ring of super-cooled magnets, to speeds and energies never before reached under controlled conditions, and crash them into one another to create and detect a host of new particles.

Built at a cost $3.8 billion and with a total expected cost of over $9 billion, it 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 domain of galaxies and black holes.

The ambitious project has been plagued, however, by a number of delays even before its brief running in September.

The collider was shut down after nine days of operation on Sept. 19 when the meltdown of a small electrical connection caused the release of a large amount of liquid helium into the 27-kilometre long tunnel, CERN officials said.

The magnets in the collider are cooled at temperatures near absolute zero to make them superconductive and thus better able to accelerate the particles to high speeds, but this means they must be warmed to normal temperatures before repair work can begin, a process that takes about a month.

Repairs within budget

The facility is also scheduled to shut down in the winter to avoid heavy electricity use at a time when Europe has a higher demand for power. The winter shutdown ends in late March or early April.

Gillies said the cost of the repair work falls within the organization's existing budget. But the further delay is a blow to the physics community, which has been waiting anxiously for the experiment to start producing results to be examined.

One thing in particular they believe they will find is evidence of the Higgs boson, a particle thought to impart mass on most other particles.

The Higgs boson plays a key role in the Standard Model of particle physics, a framework that has helped to explain the interactions of particles like electrons, quarks and photons for over 30 years. So far, however, it has never been found, and there are conflicting theories on what its characteristics, such as its mass, might be.