Status and commissioning-results of BESSY II
The new Storage Ring BESSY II in Berlin Germany is a dedicated third generation synchrotron radiation source for the VUV and soft X-ray spectral range. On April 22/sup nd/, 1998 a 1.7 GeV electron beam was stored for the first time. Despite a relatively short time for commissioning of the synchrotron radiation source, the milestones were met as scheduled. Accelerator parameters that determine the quality of the synchrotron radiation are as designed or the design goals were even exceeded. The only parameter that is still not according to design is the beam lifetime, as the baking of the vacuum system is not completed yet. The regular scientific program started according to plan in January 1999 with experiments. The front-end for 22 additional beamlines are installed and scheduled for use before the end of next year. Thus required shutdown periods will also be used to install additional hardware to improve the performance of the ring.
BESSY II feedback systems
The present status of feedback systems to counteract unwanted beam motion and coupled-bunch beam instabilities in the BESSY II storage ring is reviewed.
Establishment of a model for interpretation and correction tools for BESSY II
From the very beginning of the commissioning of the Synchrotron Radiation facility BESSY II, work has been facilitated by online interpretation and correction procedures that utilise a commonly accessible online model of the storage ring optics. The software covers all linear properties like beta functions, orbit correction, tune variation etc. Initially the model has been set up from construction and alignment data and magnetic bench measurements. All relevant parameters are retrieved from a central reference database. During commissioning, the model has been adjusted in several steps, feeding back results from orbit response measurements. The achieved agreement is demonstrated.