Magnets for RHIC

The Relativistic Heavy Ion Collider (RHIC) is a proposed research facility at Brookhaven National Laboratory for the study of extreme states of matter. By colliding two beams of ions, up to gold in mass and at energies up to 100 GeV/amu, high energy density will be achieved within the nuclei of the colliding ions, leading to a variety of fundamental effects not heretofore observed. The physics to be explored by this Collider is an overlap between the traditional disciplines of nuclear physics and high energy physics. The machine is proposed for construction in the now-empty tunnel built for the former CBA project. In addition to the tunnel, various other facilities needed for the machine are in place, including experimental halls, a beam transfer tunnel from the AGS, and a refrigerator for providing cryogenic helium. The Collider, including the magnets, is in an advanced state of design. The layout of the basic RHIC regular arc cell is shown. Seventy-two such cells are required to complete one ring. The lattice of magnets chosen in the design reflects the need for strong focussing to maintain a small beam size while coping with the severe intrabeam scattering of heavy ion beams. Each cell is 29.622 m long; it deflects the beam by 77.7 mrad and has a betatron phase advance of 900. The layout of the magnets to bring the beams into collision is shown. The characteristics of the dipole and quadrupole magnets required for the arcs and for the intersection regions are given