The Large Hadron Collider near Geneva will be out of action for at least two months, the European Organization for Nuclear Research (Cern) says.
Part of the giant physics experiment was turned off for the weekend while engineers probed a magnet failure.
But a Cern spokesman said damage to the 3.6bn ($6.6bn) particle accelerator was worse than anticipated. The LHC is built to smash protons together at huge speeds, recreating conditions moments after the Big Bang. Scientists hope it will shed light on fundamental questions in physics.
On Friday, a failure, known as a quench, caused around 100 of the LHC’s super-cooled magnets to heat up by as much as 100C. The fire brigade were called out after a tonne of liquid helium leaked into the tunnel at Cern, near Geneva. – bbc