The relativistic heavy ion collider (RHIC), presently under construction at
Brookhaven, has two concentric rings 3.8 km in circumference. There are th
ree distinct vacuum systems in RHIC. The design of these three vacuum syste
ms is presented. The measurement of helium travel within the 480 m cold bor
e beam tube and the method of locating helium leaks in the long cryostat ar
e also presented. (C) 1999 Elsevier Science Ltd. All rights reserved.