• 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.

• S. Kwiatkowski, K.M. Baptiste, J. Julian
  LBNL, Berkeley, California

Funding: *Work supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Science and Engineering Division, of the Department of Energy under contract No. DE-AC02-05CH11231.

ALS is the 1.9GeV third generation synchrotron light source which has been operating since 1993 at Berkeley National Lab. Our team is now working on the design of a new RF power source (replacement of the existing 320kW klystron with 4 IOT’s). In the new design the existing conventional crow-bar klystron protection system will be replaced with a fast disconnect switch. The switch will be constructed out of 16 high-voltage IGBT’s connected in series equipped with static and dynamic balancing system. The main advantage of using this new technology is faster action and virtually no stress for the components of the high voltage power supply. This paper will describe the hardware design process and the test results of the prototype switch unit.

• 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.