The linear accelerator at Stanford University's SLAC National Accelerator Laboratory in California is shut down and two research labs idled after a fire damaged electrical equipment that helps power the accelerator.
SLAC spokesman Andrew Gordon said on Thursday he didn't know when the accelerator would be back up and running. SLAC conducts research in high-energy physics and subatomic particles.
Gordon said the fire was confined to a school locker-sized electrical cabinet in a building above the accelerator, which is underground. The cause is under investigation.
There was some minor smoke damage around the cabinet, but the accelerator itself was not damaged.
Gordon said the fire also did not create any threat to the public.