By the beginning of 1990, three third-generation synchrotron light sources had been successfully commissioned in Grenoble, Berkeley and Trieste (ESRF, ALS and ELETTRA). Each of these new machines reached their target specifications without any significant problems. In parallel, already at that time discussions were underway regarding the next generation, the `diffraction-limited light source (DLSR)', which featured sub-nm rad electron beam emittance, photon beam brilliance exceeding 1022and the potential to emit coherent radiation. Also, at about that time, a first design for a 3 GeV DLSR was developed, based on a modified multiple-bend achromat (MBA) design leading to a lattice with normalized emittance of ∊x= 0.5 nm rad. The novel feature of the MBA lattice was the use of seven vertically focusing bend magnets with different bending angles throughout the achromat cell to keep the radiation integrals and resulting beam emittance low. The baseline design called for a 400 m ring circumference with 12 straight sections of 6 m length. The dynamic aperture behaviour of the DLSR lattice was estimated to produce > 5 h beam lifetime at 100 mA stored beam current.

No abstract

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 0 = 2 T and λ 0 = 0.2 m) the equilibrium emittances are ε x,0 = 6.5 • 10 −10 m • rad and ε y,0 = 1.3 • 10 −11 m • rad (the corresponding normalised emittances are : ε x,n = 3.8 • 10 −6 m • rad and ε y,0 = 7.6 • 10 −8 m • rad. The damping time results in τ y ≤ 3.4 ms. The dynamic acceptance including misalignment and magnet errors is in the range of A x ≤ 72 mm • mrad and A y ≤ 80 mm • mrad.

The pure insertion device (PID) lattice is a novel concept for a sinchrotron light source, where all possible light ports are irradiated by insertion devices. Up to 40% of the ring circumference is available for insertion devices. The lattice has been obtained by giving up the constraint of zero dispersion in the straight sections. However, for many SR experiments, the resulting reduction in brilliance is not of importance. An application of the PID structure for a 3 GeV storage ring is presented and discussed. With 202 m of circumference and an emittance of 14 nm.rad, it has 24 straight sections of over 3m each. Tracking studies show excellent dynamic properties of the lattice

No abstract