The European Organization for Nuclear Research earlier said an electrical failure Friday, nine days after the collider was first started, released a large amount of liquid helium into the tunnel.
Experts have gone into the 17-mile circular tunnel housing the Large Hadron Collider to check on damage caused when an electrical connection between two magnets apparently melted, said James Gillies, spokesman for the organization, which is known as CERN.
But they have to wait several weeks before the temperature can be raised from near absolute zero so they can actually go inside the equipment and fully assess the damage, Gillies said.
"They're going to have to open up and really investigate what went on there," he said. "So that's going to be two or three weeks before we can put out something that we're sure of."
But he added it is clear at least two months will be needed for the whole procedure, including the rechilling of equipment to obtain the "superconducting" properties needed to send subatomic particles streaming through the collider in beams that can be collided for studies.
That would go past the shutdown already scheduled for CERN's facility to begin its winter break. It usually shuts in mid-November and resumes at the end of March or early April, to avoid its heavy use of electricity during the winter months when Europe has high demand for power.
"We are not going to be done with this before the winter shutdown, so there will be no more beam in the LHC this year," Gillies told The Associated Press. "The winter shutdown will go according to schedule, which means that we start up the accelerator complex in the spring months."
The Large Hadron Collider was built to enable physicists to crash beams of protons into each other to study the tiniest subatomic particles that were first created after the "big bang," which many theorize was the massive explosion that formed all matter.
After the break, operators will restart the "accelerator chain," which creates the beams of protons fired through the machine to collide and create smaller particles that physicists use to study the makeup of matter and the universe.
That "is something that we do every year and it's something we have a lot of experience in doing, so there's no reason to think that that would not go rather quickly," Gillies said. "I suspect that the priority for the restart next year will be to get LHC beams as quickly as possible."
The new collider, launched with great fanfare Sept. 10, had an auspicious beginning, firing beams of protons at the speed of light first in a clockwise direction though a fire-hose-sized tube in the tunnel, then through a counterclockwise tube.
But a transformer failed about 36 hours after startup, forcing a halt in tests. The transformer was relatively easy to fix because it was outside the cold zone and it was ready to go again when the electrical fault occurred.
Scientists expected "teething problems" in getting the huge and extremely complex machine running at full power.
They hope the powerful collider will reveal more about "dark matter," antimatter and possibly hidden dimensions of space and time.
They could also find evidence of a hypothetical particle - the Higgs boson - which is sometimes called the "God particle" because it is believed to give mass to all other particles, and thus to matter that makes up the universe.
Smaller colliders have been used for decades to study the makeup of the atom. Scientists once thought protons and neutrons were the smallest components of an atom's nucleus, but experiments showed those particles are made of even smaller ones, such as quarks and gluons.
Some skeptics have expressed fears the high-energy collision of protons could imperil the Earth by creating micro black holes - subatomic versions of collapsed stars whose gravity is so strong they can suck in planets and other stars.
CERN and leading physicists dismiss the fears and maintain the project is safe.