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SLAC National Accelerator Laboratory

SSRLUO Executive Committee Meeting Minutes

Meeting Notes: May 14, 1999

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Attendees: P. Allen, S. Barrett, B. Clemens, P. Foster, B. Rupp, D. Salt, S. Traina, T. Trainor, J. Wong

Absent: J. Bilello, D. McKay, R. Scott



  • The SPEAR3 scope has expanded and the schedule has been accelerated since the original projections in the Lehman Review. The project will be funded by DOE and NIH. The $14M FY99 funding option agreed to by NIH will allow for a new Rf and the capacity to run at 500mA. The MOU between DOE and NIH is complete and in the process of being signed. Funds should be released with a specified start date of June 1. Asked whether the influx of NIH funds will impact DOE's management status of the lab, Hodgson reported that he didn't anticipate any major shift in management oversight but that this will be something SSRL management will closely monitor in Washington, DC.
  • The increase to 500mA will impact projected beamline upgrade costs by approximately 2.5 times the original estimate. P. Pianetta and T. Rabedeau are heading a task force to modify the original beamline upgrade plan to handle the 2.5X increase in stored current. Future potential beamlines are also being explored.
New Faculty/Programs
  • An appointment for Dr. P. Kuhn as assistant professor in structural molecular biology is in process and expected to be complete for a September 1, 1999 start date
  • Dr. J. Stohr will join the SSRL faculty as a professor in January '00
  • Profs. M. Greven, Z.X. Shen, R. Laughlin and S. Doniach submitted a proposal to DOE under the new initiative materials program which would develop a new research program in correlated materials which would utilize BLs 7-2 and 11-3. The scientific program should help develop a framework for a new material diffraction beamline (possibly BL 12)
Structural Molecular Biology
  • NIH-General Medical Sciences is funding 6 staff members to support the general users of the protein crystallography beamlines, as well as additional advanced instrumentation
  • NIH is interested in developing national or regional synchrotron centers. This could lead to a partnership with ALS and streamlined access to both labs.
Beamline 11
  • 26-pole wiggler exceeds all performance specs and has been mated to vacuum chamber
  • BL 11-2 will be used for XAS studies of toxic and radioactive samples; 3 FTEs will be funded from DOE
  • BL 11-1 will be a joint venture with Stanford University and The Scripps Research Institute (TSRI) for protein crystallography research with 1/3 of the beamtime available for general users; 3 FTEs will be provided by TSRI.
The Linac Coherent Light Source (LCLS)
  • Leone Panel delivered a positive report in Feb '99 that provided the clear justification to initiate an R&D program focussed around LCLS
  • R&D program will involve a multi-laboratory collaboration (SLAC/ANL/LANL/LLNL/UCLA/BNL) with DOE funding beginning in FY99
  • Possible project start date in FY02 or FY03
  • Pierre Capeder will be leaving SSRL this month. Pierre was recognized for many excellent contributions to the growth of the lab over the past 14 years.
  • Suzanne Barrett will depart at the end of July due to her husband's job relocation.
Beamline 4-2
  • After detailed internal discussions, as well as meetings with the SSRLUO and Proposal Review Panel, it was decided to increase the minimum percentage of small angle scattering on BL 4-2 to 75% when BL 11-2 is fully functional.
  • Plan to expand the hutch to accommodate non-SAS users and facilitate the transition between SAS and non-SAS setups. The increased SMB use will be advantageous in securing beamline upgrade funds in the future.


  • Hettel summarized the current status of the SPEAR 3 accelerator upgrade project. He reviewed the differences between the existing magnet lattice and the one for SPEAR 3, which has an order of magnitude less beam emittance and which will produce smaller beam sizes.
  • The reduced emittance and increased beam current (up to 500 mA) will increase photon beam focused flux density and brightness by an order of magnitude on insertion device beam lines, and up to two orders of magnitudes for higher photon energies on bend magnet beam lines.
  • The upgrade involves replacing the accelerator magnets, vacuum chamber, RF system and other components during a single 6-month shutdown, preceded with preparatory work in prior 2-3 month shutdowns.
  • The availability of SLAC personnel seen as big advantage and will reduce the number of new hires for the project.
  • Magnets will be built in China through a collaboration with IHEP (Beijing) with a considerable cost savings. Five engineers from the PRC are due in June, but there are concerns over the current status of US-PRC relations and its impact on the collaboration. Fermilab is a possible alternative magnet fabrication site, but there would be both cost and schedule impacts.
  • The preliminary magnet production schedule spans CY99-01 with installation in April '02.
  • A decision was made to make the vacuum chamber out of copper which will improve its thermal conductivity and make it passively safe for mis-steered dipole radiation. This will reduce the complexity of the orbit interlock system, which now will only have to protect against mis-steered insertion device radiation. The chamber will be built at SLAC.
  • The expected delivery time for SPEAR 3 beam to users is ~Dec '02.


  • Of the 25 functional beamlines 18 are designed for 100mA and 7 for 200mA. The three stations under construction are designed for 500mA. Thus the decision to run SPEAR3 at 500mA will require a comprehensive beamline upgrade program.
  • Benefits of SPEAR3 include increased flux (5-20x), reduced beam size, and improved stability.
  • Upgrade challenges include the increased power density (5-14x), higher optical performance requirements and the aggressive upgrade schedule.
  • Anticipate using LN cooled monochromators for power densities >2W/mm2 and intensively water cooled mono crystals up to 2W/mm2
  • BL 11-2 will have the first LN mono at SSRL; anticipate commissioning this summer
  • Upgrade program includes new single crystal, Si mirrors with side cooling for most high power beamlines
  • Plan to replace existing 9-pole wigglers on beamlines 4 and 7 with 18-pole wigglers which will allow for more flux, a "squarer" fan, and reduced orbit excursion.
  • Beamline upgrade project estimated at $36.7M.
  • Committee was asked to consider whether it would be preferable to migrate SPEAR3 to 500mA as fast as possible (ie., before all bend magnet beam lines were able to accommodate the increased power loading) or raise the ring current in concert with the power rating of the beam line with the lowest safe power rating. In the former case some beam lines would have carbon filters installed to reduce the beam line power to an acceptable level or individual branch lines could be temporarily closed.


S. Barrett reviewed the user demand for the first two-thirds of the FY99 user run which averaged 147% across all beamlines. Beamlines 6-2, 7-2, 9-1, and 10-2 exceed 300% user demand (note: a fully subscribed beamline is equal to 100% user demand). The user community remains relatively pleased with the quality of the beam (83% rating the beam Excellent or Very Good). Overall satisfaction with beamtime was rated Excellent or Very Good by 79% of respondents. When asked about any common themes in user complaints, it was pointed out that the difficult start up in November as well as the RF problem earlier this Spring was a consistent complaint.

The committee was informed that the excess housing that Stanford was trying to secure from Moffet Federal Airfield is no longer an option for inexpensive user accommodations. The housing will be used by Army personnel that have been forced to vacate the Presidio in San Francisco. It was asked whether SSRL could adopt a European-type mode of funding graduate student expenses through scholarships or travel grants. Barrett will look into this and get back to the committee on the feasibility of such a program.

The need to further define the criteria for the submission and evaluation of this year's recipient of the annual Farrel W. Lytle Award was discussed. It was decided that all nominations should be accompanied by a 1-2 page letter outlining the nominee's qualifications or contributions to synchrotron-based research at SSRL. It was agreed that both SSRL staff and the user community are eligible for the award. Specific criteria will be drafted by J. Wong and forwarded to the committee for review. The annual Lytle Award winner will be posted on the SSRL web page and in the annual Activity Report. The evaluation committee will consist of the SSRLUO-EC, Farrel Lytle, and a representative from SSRL.

J. Wong discussed the need to have more formal check-out procedures at the beamline. It often takes the x-ray experimental support group several hours to realign the beam and configure it for the next user group. The process could be simplified if the departing user group was required to document how the beamline was left. Barrett will discuss the proposal with H. Tompkins to determine how bad the problem is and how best to solve it without creating too much of a burden on the users or staff.

It was suggested the web version of the User Support Form be amended to include a text box to add setup details that aren't necessarily called out in the standard form.

The committee felt it was important to improve communication between the Executive Committee and the general SSRL user community. It was agreed the Barrett would send out a brief email to the user community informing them that a SSRLUO-EC meeting had been held including the major topics of discussion and where to find the detailed minutes on the web.

There was some concern about the projected 6-month shutdown for SPEAR 3 and its effect on the user community. Most members felt that as long as users were given sufficient notice to plan their research and grant activities accordingly, as well as to investigate the experimental access procedures at other synchrotron laboratories, the impact could be minimized. The 6-month shutdown is projected to begin April 2002.

Problems encountered when trying to FTP files for the annual Activity Report submission will be looked into with L. Dunn and the computer group. Asked to include a summary computer update during the next meeting.

Questions: with the new SPEAR 3 capabilities will there also be improved experimental support facilities, including more storage space? Can we provide dry ice?

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