LIFETIME, STABILITY AND ACCELERATOR DEVELOPMENTS AT NSLS

In the past two years, the accelerator developments which have had a major impact on operations of the VUV and X-ray storage rings have been twofold. On the VUV ring a fourth harmonic rf cavity lengthens the electron bunch and thereby increases the Touschek limited lifetime. This results in a significant improvement in integrated current over a fill. Secondly, global analog orbit feedbacks, based on an harmonic correction scheme, have been implemented on both the VUV ring and the X-ray ring to reduce beam motion. The stabilization is done in the vertical plane in the VUV ring and in both planes in the X-ray ring. In addition, three local feedbacks are operating for X-ray ring insertion beamlines and three are being commissioned. We discuss orbit stability improvement on both rings, lifetime improvement on the VUV ring, and briefly a few selected projects under way.