Accelerator slowdown.Scientists are working overtime to get the Tevatron up to speed.

Particle Accelerator Blues

Particle accelerators often have trouble when they first start up, so it's no surprise that the Tevatron has run into difficulties in the 10 months since its $260 million refit. Scientists are confident they can eventually fix the problems, but "we wanted to be farther along than we are now," says Mike Witherell, director of the Fermi National Accelerator Laboratory (Fermilab) in Batavia, Illinois, the Tevatron's home.

Thanks to problems with magnets and with handling particle beams, the Tevatron has achieved just 1% of its expected near-term goal for integrated luminosity, which, roughly speaking, is a measure of how much data the Tevatron produces. These problems need to be resolved if the Tevatron is to meet many of its scientific goals, such as accurately determining the properties of the top quark and a force carrier known as the W particle. "The performance requirements are quite demanding, especially on precision measurements," says Daniel Froidevaux, a physicist at the CERN accelerator near Geneva, Switzerland.

Unless the machine can be brought up to peak capacity, the Tevatron will be downgraded from a long shot to a noncontender in the race to find the Higgs boson: a huge, undiscovered particle that theory says is the source of mass. Some physicists are hoping that the Higgs boson will be just within the Tevatron's reach, and that the machine can snatch it before CERN's Large Hadron Collider comes online in 2007. "If we push to the limit, and the mass is low, we can get there," says Witherell.

Although scientists are nervous, they still believe that the Tevatron will hit its stride. "I'm sure this thing will take off," says Froidevaux. "I really hope so. I really hope so."

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