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SLAC National Accelerator Laboratory

SSRLUO Executive Committee Meeting Minutes

Meeting Notes: April 28, 1997

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Attendees: P. Allen, S. Barrett, B. de Vos, A. Fischer-Colbrie, J. Johnson, D. McKay, D. Segel, D. Shuh, H. Thompson Absent:, P. O'Day, R. Prince, R. Stevens

Director's Presentation (A. Bienenstock)

The SSRL director opened the meeting with a discussion of the proposed 3.5% budget increase in the President's budget for FY98. Since the last SSRLUO meeting in March the possibility of a 7% increase, as proposed by Senator Gramm and the Senate Science and Technology Caucus, has decreased significantly. Dr. Bienenstock suggested that the SSRLUO prepare a letter for the Chair of the Energy and Environment Subcommittee of the House Appropriations Committee and the Chair of the Energy and Water subcommittee of the Senate Appropriations Committee which recognized the present budget limitations and expressed support for an increased budget in FY98. The SSRLUO was also encouraged to express their appreciation to the OMB and OSTP for overcoming the projected 8% decrease originally called for in the FY98 budget. The President's budget includes a 7.6% increase for NIH and this, too, will recognized by the SSRLUOEC in the form of a letter.

Keith Hodgson informed the SSRLUO-EC members about an on-line survey being conducted by the National Center for Research Resources of NIH. The survey results will be used to update their strategic plan and all structural biology users are encouraged to complete the simple survey at http:\\

Dr. Bienenstock then went on to discuss the latest status of the Birgeneau Committee. The questionnaire has increased from 6 questions to 10. The new questions address how the various synchrotron facilities complement each other, 4th generation light sources, and the impact of a shutdown of one of the existing synchrotron user facilities. K. Hodgson stressed that SSRL should stress niche communities and specialties that are not readily transferable from one facility to another. This will be a difficult aspect to quantify for the committee.

A. Bienenstock finished by saying the science is doing well again on Capitol Hill. In spite of budget cuts science budgets are staying constant or project slight increases. He also stated that the synchrotron radiation community is viewed as a model of resource sharing in its multidisciplinary approach to biotech research.

SPEAR3 Upgrade - The Scientific Case (S. Brennan)

Sean presented a detailed description of what SPEAR3 would mean to users in terms of emittance, brightness, and flux density. There are two competing lattice configurations for SPEAR3. Either version would be a significant improvement in emittance, brighness and flux density. Several waterfall charts compared the focused flux density of SPEAR3 with SPEAR2, NSLS, and APS beamlines. Flux density increases range from 7-12 fold on insertion device beamlines. Bend magnets would see an increase in their critical energy from 4.7 keV to 7.1 keV. This increase, coupled with the reduced source size and doubling of current, would result in flux density increases ranging from ~20 at 1 keV to ~80 at 8 keV to ~150 at 20 keV. It is Sean's contention that for most experiments conducted at SSRL flux density is more important than brightness. The SPEAR3 workshop in May will examine this issue more fully.

SPEAR3 Upgrade - The Lattice (B. Hettel)

Bob Hettel began his presentation with a review of the current booster and injector capabilities, as well as the configuration of the present SPEAR2 lattice. He outlined the goals, design tasks, and future upgrade possibilities of a SPEAR3 lattice. SPEAR2 has a 130 nm-rad emittance, while the SPEAR3 lattice would decrease emittance to 18 nm- rad.

The primary lattice under study has separated function magnets that preserve existing beamline source points. The horizontal and vertical beam sizes in the straight sections would be approximately 0.5 mm and 0.035 mm respectively. Another lattice using combined function magnets will also be studied. This lattice would have horizontal and vertical beam sizes of 0.35 mm and 0.025 mm respectively, and might have longer arc straight sections. However, it is likely that injecting into this lattice would be more difficult than for the separated function lattice; more study is required to determine the practicality of adopting the combined function lattice.

The Linac Coherent Light Source: An X-Ray Free Electron Laser (J. Arthur ):

John Arthur gave a very informative presentation on the LCLS research project. This project promises to deliver a free electron laser operating at hard x-ray wavelengths, a unique source with unique characteristics. This is feasible at SLAC due to a convergence of special circumstances: the availability of the SLAC linac, the accelerator physics expertise at SLAC, and the x-ray physics expertise at SSRL.

John explained that due to the ground-breaking nature of the project, a gradual, phased approach is planned. There presently is no special funding for the project. It is internally supported with the equivalent of 3-4 FTEs and this level of support is anticipated for the next two years. SSRL is seeking $2-$3 million from DOE for R&D work in FY98 and 99. The construction phase of the LCLS would last about 3 years with a total budget in the neighborhood of $70 million. This project has already attracted worldwide interest from x-ray and accelerator scientists. The current R&D work involves collaboration with about 50 scientists at several universities and national laboratories.

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