A Little Big Bang; March 1999; Scientific American Magazine; by Mukerjee; 6 Page(s)

The subterranean tunnel curves away in both directions, sweeping its two slender beam tubes quickly out of sight. The inside is softly lit in subtle grays-of concrete, of steel, of shiny insulation. A scent of metal shavings lingers in the cool air, and from a distance comes a muffled rattle, of a machine checking for vacuum leaks within the tubes. As we walk along, the tunnel straightens out, and the slim beam tubes merge into a single fat one. Climbing over a set of crisscrossing pipes, we emerge into a cavernous chamber, glowing yellow in sodium floodlights. In the middle of the floor is painted a black circle with the words "Collision Point."

Just above that point in space, experimenters will create in June matter as hot and dense as in the first microsecond after the big bang. The Relativistic Heavy Ion Collider (RHIC, pronounced "Rick"), just being completed at Brookhaven National Laboratory on Long Island, is designed to accelerate nuclei ranging from hydrogen (a single proton) to gold (197 protons and neutrons). When at rest, a nucleon-that is, a proton or neutron-has a mass or energy of about 1 GeV, or a billion electron volts. RHIC's superconducting magnets will accelerate the nuclei so that, because of relativity, each nucleon within a nucleus will attain any desired mass or energy from 10 to 100 GeV.