The giant Large Hadron Collider, the world’s largest and most expensive scientific experiment, will be shut down for at least two months, scientists at the European Center for Nuclear Research, or CERN, in Geneva said today.
The shutdown casts into doubt the hopes of CERN physicists to achieve high-energy collisions of protons in the machine before the end of the year. “It’s too early to say whether we’ll still be having collisions this year,” James Gillies, head of communications for CERN, said in an e-mail message. The laboratory shuts down to save money on electricity during the winter.
A gala inauguration party scheduled for Oct. 21 will still take place, Dr. Gillies said.
The collider is designed to accelerate the subatomic particles known as protons to energies of 7 trillion electron volts, far surpassing any other accelerator on Earth, and bang them together in search of new particles and forces.
After the initial success of threading protons through the machine on Sept. 10, physicists had hoped they could move ahead quickly to low energy collisions at 450 billion electron volts and then 5-trillion-electron volt collisions as early as mid-October.
A series of mishaps, including the failure of a 30-ton electrical transformer, have slowed progress since then. In the worst incident yet, on Friday, one of the giant superconducting magnets that guide the protons failed during a test. A large amount of helium, which is used to cool the magnets to within 3.5 degrees Fahrenheit of absolute zero, leaked into the collider tunnel.
In a terse statement, the lab said that an electrical connection between the magnets had melted due to the high current running through it. In order to fix it, engineers will have to warm up that section of the tunnel, and then cool it all the way down again.
Physicists say that such setbacks are an inevitable part of starting up such a large and complicated machine, which has cost $8 billion and taken 14 years. “This is just an unfortunate fact of life when starting up a machine like the LHC,” Dr. Gillies said.
By DENNIS OVERBYE
Published: September 20, 2008
Source: The New York Times