Commissioning and performance of the Advanced Light Source

The Advanced Light Source (ALS) at the Lawrence Berkeley Laboratory is the first of the lower energy (1 to 2 GeV) third-generation synchrotron radiation facilities to come into operation. Designed with very small electron beam emittances, to operate with long insertion devices to produce very high brightness beams of synchrotron radiation in the VUV and soft X-ray regions of the spectrum, these facilities are complementary to the higher energy (6 to 9 GeV) facilities designed for harder X-radiation. From the earliest periods of their design it was recognized that the performance of the required low-emittance lattices would be dominated by nonlinear particle dynamics caused by the strong lattice sextupoles required for chromatic correction, the effects of undulators and wigglers, and the requirement for very narrow-gap vacuum vessels. Commissioning of the ALS storage ring began early in 1993. In this paper we will briefly review the main characteristics of the storage ring design, describe our commissioning experiences, and review the present performance and performance limitations of the facility