• A. Madur, S. Marks, S. Prestemon, D. Robin, T. Scarvie, D. Schlueter, C. Steier
  LBNL, Berkeley, California

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

In 2006, the 30mm period In-Vacuum Insertion Device (IVID) was operational for the femtosecond phenomena beamline at the Advanced Light Source (ALS) of Lawrence Berkeley National Laboratory. Since then the IVID has been demonstrating unexpected behaviors especially at small gaps (minimum gap = 5.5mm). The main observations related to these issues are partial or total beam losses as well as sudden pressure increases while operating the IVID gap. This paper is reporting these observations and describes the investigations and the repair attempt performed on this insertion device.

• S. Prestemon, D.R. Dietderich, A. Madur, S. Marks, D. Schlueter
  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.

Superconducting undulators are currently under development at a number of light sources to serve as the next generation of insertion devices, with higher fields providing enhanced spectral range for users. Most of these devices are designed with wire-based technologies appropriate for periods greater than ~10mm. New undulator concepts yielding very short-period, high-field devices with periods of a few millimeters and a K~1 have the potential to significantly reduce the cost and enhance the performance of FEL's. Here we describe a design using high temperature superconductor tapes that are commercially available, and that promise a cost-effective fabrication process using micromachining or lithography. Detailed magnetic and spectral performance analysis will be provided.

• 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.