Design of a damping ring for the SB-Linear-Collider project at DESY

For the SB-Linear-Collider project (SBLC) at DESY a redesign of the damping ring has been performed, mainly in order to optimise the dynamic aperture. The lattice of the proposed damping ring has a DBA structure, similar to the 3rd generation light sources ESRF, APS and SPRING-8. The damping ring is build up with 6 superperiods. The straight sections between these periods are used for the injection, ejection and rf-cavities. In turn, each superperiod consists of 6 DBA cells. The straight sections of these cells are used for the installation of the wigglers, which are needed for the damping. With the installation of overall 150 m of wigglers (B/sub 0/=2 T and /spl lambda//sub 0/=0.2 m) the equilibrium emittances are /spl epsi//sub x,0/=6.5.10/sup -10/ m.rad and /spl epsi//sub y/,0=1.3.10/sup -11/ m.rad the corresponding normalised emittances are: /spl epsi//sub x,n/=3.8.10/sup -6/ m.rad and /spl epsi//sub y,0/=7.6.10/sup -8/ m.rad. The damping time results in /spl tau//sub y//spl les/3.4 ms. The dynamic acceptance including misalignment and magnet errors is in the range of A/sub x//spl les/72 mm.mrad and A/sub y//spl les/80 mm.mrad.