An electrical failure in the world's biggest particle collider will delay a series of physics experiments until spring 2009, the operators said Tuesday.

The European Organization for Nuclear Research, known by the French acronym CERN, said repairs to the underground facility near Geneva, Switzerland, will run into the lab's normal winter shutdown, leading to a longer shutdown than the two or three months needed to fix the problem.

The delay is a blow for the massive physics experiment, built at a cost of $3.8 billion and with a total expected cost of over $9 billion.

CERN officials said the Large Hadron Collider was shut down after nine days of operation when the meltdown of a small electrical connection caused the release of a large amount of liquid helium into the 27-kilometre long tunnel, near the Franco-Swiss border.

The collider 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.

The magnets in the LHC are cooled at temperatures near absolute zero to make them superconductive and thus better able to accelerate the particles to high speeds. So before any repairs can be made, the tunnels have to be warmed to normal temperatures to allow for a more detailed examination of the problem.

The process to raise the temperature takes about a month, with another month required to lower the temperature back to near absolute zero.

That process will take the facility into its already scheduled winter break, when it will shut down 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.

In its nine days of operation, the collider had sent beams of protons running in opposite directions through the underground circuit, but had yet to collide the particles.

The collider 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.

One thing in particular they believe they will find is 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. But so far it has never been found.