• F. Sannibale, K.M. Baptiste, J.N. Corlett, T.M. Huang, S. Kwiatkowski, D. Li, J. Qiang, J.W. Staples, R.P. Wells, L. Yang, A. Zholents
  LBNL, Berkeley, California
• J.W. McKenzie
  STFC/DL/ASTeC, Daresbury, Warrington, Cheshire

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231

A high-brightness high-repetition rate photo-injector based on a normal conducting 187 MHz RF cavity design capable of CW operation is under construction at the Lawrence Berkeley National Laboratory. A cathode field of ~20 MV/m accelerates electron bunches to 750 keV with peak current, energy spread and transverse emittance suitable for FEL and ERL applications. A vacuum load-lock mechanism is included and a 10 picoTorr range vacuum capability allows most types of photocathodes to operate at a MHz repetition rate with present laser technology. The status of the project is presented.

• C. Steier, B.J. Bailey, K.M. Baptiste, W. Barry, A. Biocca, W.E. Byrne, P.W. Casey, M.J. Chin, R.J. Donahue, R.M. Duarte, M.P. Fahmie, J. Gath, S.R. Jacobson, J. Julian, J.-Y. Jung, A.M. Kritscher, S. Kwiatkowski, S. Marks, J.P. McKean, R.S. Müller, H. Nishimura, J.W. ONeill, G.J. Portmann, S. Prestemon, D. Robin, S.L. Rossi, F. Sannibale, T. Scarvie, D. Schlueter, B. Shuman, A.Z. Smith-Baumann, G.D. Stover, CA. Timossi, W. Wan, T. Warwick, J.M. Weber, R.P. Wells, E.C. Williams
  LBNL, Berkeley, California

Funding: This work was supported by the Director, Office of Science, U. S. Department of Energy under Contract No. DE-AC02-05CH11231.

The upgrade of the Advanced Light Source to enable top-off operation has been ongoing for the last four years. Activities over the last year have centered around radiation safety aspects, culminating in a systematic proof that top-off operation is equally safe as decaying beam operation, followed by commissioning and full user operations. Top-off operation at the ALS provides a very large increase in time-averaged brightness to ALS users (by about a factor of 10) as well as improvements in beam stability. The presentation will provide an overview of the radiation safety rationale, commissioning results, as well as experience in user operations.