Revived collider seeks physics firsts.

The world's highest-energy particle accelerator has fired up again after a 3-year shutdown. Newly completed renovations, which began 8 years ago, are expected to boost by a factor of 10 the number of proton-antiproton collisions produced in the Tevatron at the Fermi National Accelerator Laboratory in Batavia, Ill. (SN: 7/1/95, p. 10).

To upgrade the Tevatron, Fermilab built a new, $260 million, subordinate accelerator, known as the Main Injector, that's 2 miles in circumference. It creates four times as many antiprotons to feed to the main Tevatron ring as did its predecessor accelerator. Energy Secretary Bill Richardson and other dignitaries dedicated the new injector on June 1.

Extensive overhauls of the Tevatron ring's two main detectors--to be completed by early next year--will wring more information from the higher collision rate. Altogether, these upgrades should open up new realms of physics to experimental exploration, Fermilab scientists say.

The improvements will "make us really the world center for physics" until roughly 2006, says Joseph Lykken of Fermilab. That's when the Large Hadron Collider, an accelerator now being built in Switzerland, is slated to start up.

Until then, the renovated Tevatron will have first shot at such prizes as the long-sought Higgs boson and so-called supersymmetric particles, he says. Finding the Higgs particle may solve the mystery of why matter has mass. Supersymmetric particles might reveal hidden links between the particles that carry forces and those that make up matter.