Design of the SPEAR 3 Light Source

The venerable SPEAR storage ring will be replaced in 2003 with a modern, low emittance 3 GeV ring optimized for producing high flux and high brightness photon beams at the Stanford Synchrotron Radiation Laboratory. SPEAR 3 will have an emittance of 18 nmrad, reduced from 160 nm-rad, and a 500-mA beam current, increased from 100 mA. A water-cooled copper vacuum chamber will be thermally stable and, together with mode-damped RF cavities, will assure multibunch beam stability. Beam lines will see one to two orders of magnitude increase in beam flux density and brightness after they have been upgraded for the higher beam power. A 6-month ring installation is planned to minimize the impact on the SSRL user program. SPEAR 3 accelerator design and beam properties are reviewed.