• R. Bartolini, C. Christou, J.H. Han, I.P.S. Martin, J. Rowland
  Diamond, Oxfordshire
• D. Angal-Kalinin, D.J. Dunning, F. Jackson, B.D. Muratori, N. Thompson, P.H. Williams
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

We present the progress with the design of the 2.25 GeV superconducting linac for the NLS project. We discuss the performance achieved, the optimisation strategies, the relevance of microbunching instability and the analysis of the effect of various jitter sources

• C. Christou, J.A. Dobbing, R.T. Fielder, I.P.S. Martin, S.J. Singleton
  Diamond, Oxfordshire

Diamond Light Source has delivered beam for users exclusively in top-up mode since the end of October 2008. In this mode, a small number of single bunches are injected into specific buckets of the storage ring every ten minutes in order to maintain a constant beam current and fill pattern. During top-up the storage ring current is held within a window of approximately 1.5mA around the target current, generally 250mA, for a variety of fill patterns, including a two-thirds storage ring fill and a hybrid fill in which an intense single bunch is added to the normal fill pattern. Top-up has run continuously for several days on many occasions, with injection efficiency into the storage ring of typically 60%-95% even with 10 in-vacuum insertion device in operation with a permitted minimum gap of 5 mm. The effect of insertion devices, pulsed magnet stability and storage ring beam optics on top-up reliability and performance is examined, and the development of tools for the control of top-up and storage ring fill is detailed.