Collider Operations on Hold Until Next Year

The world’s newest and largest particle accelerator, the Large Hadron Collider, will not begin operations again until April, officials at the European Center for Nuclear Research said Tuesday.

The machine is built to speed the subatomic particles called protons to nearly the speed of light and then smash them together in search of new forms of matter and energy that cannot be produced in smaller machines. Two weeks ago, the center for nuclear research, which is outside Geneva, sent the first beams of protons around the machine’s 17-mile-long underground racetrack.

But last Friday the machine was shut down after an electrical connection between two of the superconducting electromagnets that steer the protons suffered a so-called quench, heating up, melting and leaking helium into the collider tunnel. Liquid helium is used to cool the magnets to superconducting temperatures of only about 3.5 degrees Fahrenheit above absolute zero. Stray heat can cause the magnets to lose their superconductivity with potentially disastrous consequences.

To make repairs, it will be necessary to warm the magnets up and then cool them back down again, which takes at least two months, engineers say. And that leaves scant time to run the collider before it has to shut down for the winter in early December to save money on electricity. - nyt