The world's largest atom smasher near Geneva is expected to be out of action longer than expected and will cost millions of francs to repair.
The Large Hadron Collider, a SFr6 billion ($5.46 billion) machine designed to recreate the earliest moments of the universe, suffered a cooling-system malfunction nine days after scientists started it in September.
James Gillies, spokesman of the European Nuclear Research Organisation (Cern) , pushed the restart date back until early summer and said repairs could cost up to SFr35 million ($29.22 million).
"If we can do it sooner, all well and good," he said, adding that the organisation has the budget to do the repairs.
In order to function properly the machine must run at temperatures colder than outer space. Physicists hope that using it to smash atomic particles together will help explain what happened when the universe was one-trillionth of a second old.