Number 146 (Story #4), October 5, 1993 by Phillip F. Schewe and Ben Stein FERMILAB'S CRYOGENIC COOLING SYSTEM has been designated as a Mechanical Engineering Landmark by the American Society of Mechanical Engineers. The cryogenic system, the largest in the world, maintains Fermilab's Tevatron collider at only a few degrees above absolute zero; keeping the machine's magnet coils superconducting permits higher currents, higher magnetic fields, and therefore higher-energy proton beams. The cooling system cycles 5000 liters of liquid helium an hour through the Tevatron magnet network. (Fermilab news release, 27 Sept. 1993.)