THE SOLEIL BPM AND ORBIT FEEDBACK SYSTEMS

SOLEIL is a third generation light source built in France, near Paris. Its BPM system is important for machine physics studies and for delivering stable beams to the users. A beam stable to 1/10th of the dimensions requires submicron stability in the vertical plane. The monitors anchored either to the girders or to the ground, are fixed points of the vacuum chamber. The electronics design was driven by combined efforts through active communication between accelerator laboratories (SOLEIL at first, later joined by DIAMOND) and Instrumentation Technologies. The result is the "Libera Electron" beam position processor. This paper reports on the performance of this new electronics installed on SOLEIL Storage Ring. It combines a 0.2µm rms resolution and micron level stability for beam delivery with accurate turn-by-turn measurements (3µm resolution at 0.8MHz) for machine commissioning and beam physics studies. It also features position interlock, tune measurement, and post-mortem capabilities. A Slow Orbit Feedback for correcting low frequency drifts (0 to 0.1Hz) is currently in operation. The Fast Orbit Feedback to be implemented soon will suppress higher frequency perturbations up to 100Hz.