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Last Updated: | 23 JAN 2002 |
| Content Owner: | L. Dunn | |
| Page Editor: | L. Dunn |
**** **** **** * * * * * * **** **** **** * * * * * * **** **** * * **** HEADLINES - a digital monthly publication
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Contents of This Issue:
1. Science Highlight - Can Sulfur X-ray
Spectroscopy Save the 17th-Century Swedish Warship Vasa?
(contact: Magnus Sandström, magnuss@struc.su.se)
The famous 17th-century Swedish warship Vasa has been on display in the Vasa Museum in Stockholm since 1990. The Vasa sank on its maiden voyage in 1628, and was raised in 1961 after 333 years in the cold brackish water of the Stockholm harbor. After extensive conservation treatment, the oaken Vasa appeared in good condition. However, high acidity and a rapid spread of sulfate salts were recently observed on many wooden surfaces along with signs of deterioration of the wood. A research team led by Prof. Magnus Sandström, University of Stockholm, studied the problem by using X-ray absorption spectroscopy at the sulfur K-edge, with data recorded on SSRL's Beam Line 6-2. They studied wooden core samples from the Vasa to identify the sulfur compounds. The sulfur x-ray spectra, measured on samples extracted at various depths of the cores, unexpectedly revealed large amounts of embedded elemental sulfur (0.2-4 mass%) in the wood together with sulfate and, in minor amounts, several sulfur compounds of intermediate oxidation states. X-ray photoelectron spectroscopy (XPS) was also used to quantify all elements at the same depths. The study shows that in the humid museum atmosphere, sulfur oxidation produces sulfuric acid. This oxidation is catalyzed by iron species in the wood released from the completely corroded original iron bolts, as well as from those remaining in the Vasa is enough to produce more than 5000 kg of sulfuric acid when fully oxidized. Acidic wood hydrolysis is a severe threat to the continued preservation of the Vasa, and pH-raising treatments must be applied to arrest wood degradation.
More information regarding this research, including the reference to
the recent publication in Nature can be found at:
http://www-ssrl.slac.stanford.edu/research/highlights_archive/vasa.html
Another account of the research appeared in the February 21st edition of the Stanford Report.
2. SPEAR3 Shutdown Begins a New Era at SSRL
(April 2003-January 2004)
(contact: Cathy Knotts, knotts@ssrl.slac.stanford.edu)
Preparations for the SPEAR3 upgrade have been underway at SSRL since the project began in June 1999. The major installation of this world-class third generation light source will take approximately 6 months, beginning in April 2003. Technical updates are available on the SSRL SPEAR3 website.
Commissioning of the new storage ring is expected to take an additional 2-3 months, and we expect to resume general user scheduling on many beam lines in January 2004. Some beam lines have already been equipped to make them compatible with SPEAR3, and others are scheduled for upgrades in the near future. Since the beam line upgrade project is resource limited, the project is proceeding on a task priority basis. The first priority is to ensure all front ends are 500 mA capable when SPEAR3 starts up in the Fall 2003. The insertion device beam line upgrades are the second priority. It is anticipated that BLs 5, 6, 9, 10, and 11 will be 500 mA capable by January 2004. The BL7 project should be complete several months later. Resource limitations will delay the BL4 upgrade at least a year from the BL7 schedule (based on current projections of funding availability). Upgrades to the bend magnet beam lines will follow the insertion device beam line upgrades as resources permit. This plan could be accelerated if additional resources become available.
SSRL strongly encourages and seeks user input and is working with the SSRL Users' Organization Executive Committee (SSRLUO-EC) to ensure that users are aware of SSRL activities, including plans for the SPEAR3 shutdown. At the last meeting of the SSRLUO-EC on October 19, 2001, SSRL Director Keith Hodgson suggested that SSRLUO-EC form a small group representing the various fields/techniques that comprise the SSRL user community in order to provide input into user concerns and needs as they relate to the shutdown. (see: meeting minutes)
In response to this call for user input, the SSRLUO-EC has formed a subcommittee to represent users and to suggest ways that SSRL may be able to mitigate the resulting loss of beam time to users during the SPEAR3 shutdown in 2003. The subcommittee consists of Uwe Bergmann, Corwin Booth, Paul Foster, Lipika Basumallick, Ben Bostic, Nicholas Pingitore, and Vittal Yachandra. The agenda for the next SSRLUO-EC meeting includes a presentation from this subcommittee as well as a SPEAR3/beam line development update. All interested SSRL users are invited and encouraged to attend this meeting that will be held on Friday, March 15, 2002 from 10:30 am - 12:30 pm. (see: meeting agenda and location)
3. SSRL Proposal Review Panel Holds 52nd Meeting
(contact: Russ Chianelli, chianell@utep.edu)
The SSRL Proposal Review Panel (PRP) held its 52nd meeting on February 1-2, 2002. The PRP plays an important role in the peer-reviewed proposal process as well as provides strategic advice and guidance on SSRL's programs and long range planning. During this meeting, Keith Hodgson gave an overview of the SSRL scientific program and strategic issues for consideration by the PRP. Jo Stöhr provided an update of the materials science program as well as a plan to expand this area in the future. Tom Elioff gave a technical update on the SPEAR3 project. Tom Rabedeau summarized recent beam line development upgrades in preparation for SPEAR3 as well as the impact of the scheduled shutdown on beam lines. (See Tom's viewgraphs)
Cathy Knotts gave a presentation on user operations. The PRP approved the request to grant a one-year extension to proposals that would lose their access to SSRL during the shutdown (April 2003-January 2004). The PRP subpanels reviewed 59 new proposals and considered a number of proposal extension requests. At the closing session on Saturday, PRP Chair Russ Chianelli (UTEP) recognized the good work being conducted at SSRL, particularly noting the presentations made on the material science program, SPEAR3, and beam line development. The PRP noted that the progress made on the SPEAR3 project, the flexibility in overcoming various unexpected problems, and the fact that the upgrade is proceeding during normal SPEAR2 operations is quite remarkable and deserves special commendation.
Two other advisory meetings were held in conjunction with the PRP. The NIH Structural Molecular Biology Advisory Committee met on Friday morning to review activities and discuss strategies for the future. A meeting of the NIH NCRR Collaboratory Advisory Panel was held on Saturday afternoon; this session included an annual progress report, presentations on collaboratory software architecture and SSRL computing and networking architecture, a remote access demonstration, and a beam line tour.
4. LCLS Science Advisory Committee Meets and LCLS
makes the President's FY2003 budget for Project Engineering and
Design
(Jo Stöhr, stohr@ssrl.slac.stanford.edu)
The President's budget for FY2003 includes proposed funding for project engineering and design (PED) for the LCLS. If appropriated by Congress, this will mark a real transition for the LCLS project, from an R&D phase into the first phase of a construction project. In the proposed schedule, two years of PED would be followed by a three-year construction cycle, with commissioning beginning in the fall of 2007. This exciting information provided an important context for the LCLS SAC meeting.
The LCLS SAC met on February 8, 2002 to formulate a strategy for the experimental program development and discuss the future role of the committee. At the beginning of the meeting, John Galayda (LCLS project manager) gave an overview of the LCLS. In particular, he addressed the new scope of the construction project which enables more accurate definition of cost, the establishment of realistic performance metrics for defining completion of the construction project, and allows for flexibility in defining and funding the science program (since experiments are more than 5 years away). The new scope includes facilities to characterize the LCLS beam and test the ability to filter and focus the beam, synchronize it with a pump laser, split/delay it for pump/probe experiments and monochromatize it. Explicit end-of-line instrumentation for the scientific experiments is not included.
Jerry Hastings informed the SAC about the properties and scientific potential of the proposed sub-picosecond photon source (SPPS) which would use the existing SLAC Linac and could be operated during a 2003/2004 time window. It would not only serve as an important stepping stone toward LCLS, but also as a powerful source that would allow forefront experiments in the area of femtosecond x-ray dynamics by pump/probe methods. It would deliver about 100 femtosecond pulses containing about 107 photons per pulse. The SAC discussed possible funding schemes for this exciting source and expressed its enthusiasm for seeing the experiment move forward.
Using the LCLS timeline provided by John Galayda as input, the SAC then formulated a plan for the development and funding of the experimental facilities on LCLS. For the scientific program, the SAC strongly endorsed the principle of open, peer-reviewed access to LCLS, with a competition for access based on scientific quality and importance. In this general user (not PRT or CAT) model, experimental facilities will be funded through joint user/SSRL proposals to funding agencies. The SAC will play an important role in the selection and coordination of the proposals. In particular, the SAC established the following timeline for the development of proposals:
May 2002: Call for "Letters of Intent" for scientific experiments October 2002: Planning workshop, formation of scientific teams June 2003: Submission of proposals to SAC January 2004: Review of proposals by SAC, clearance for submission to funding agencies March 2004: DOE accepts proposals for instruments October 2004: First funding of instruments
Before May of this year the LCLS SAC will be reconstituted and in the future it will serve as an external advisory and oversight committee. The new SAC will be chaired by Prof. Roger Falcone of UC Berkeley.
5. Plans for an Australian Light Source
(contact: Jeff Corbett, corbett@ssrl.slac.stanford.edu)
Interim Project Director Max Frank and Technical Director John Boldeman visited SSRL on February 14 to present plans for the 3 GeV Australian National Synchrotron Light Source to be constructed at the University of Monash in Melbourne, Australia. To facilitate the project, the Victorian government has committed funds for a 5-year construction time line. One goal is to boost burgeoning economic activity in the biomedical science and mining sectors. Similar to SPEAR3, the storage ring calls for a 12-cell, 200 meter lattice with < 20 nm-radian emittance and up to 200 mA beam current in the initial phase of operation. A complement of 3 undulators, 1 wiggler and 5 dipole beam lines (one experimental station per beam line) is expected to deliver photons for macromolecular crystallography, powder diffraction, x-ray microprobe and XAFS in the late 2007 time frame. At full build out, Boomerang will provide up to 10 ID beam lines and 20 dipole stations.
6. Upcoming Events at SSRL and Elsewhere
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7. User Research Administration Announcements
(contacts: Cathy Knotts,
knotts@slac.stanford.edu,
Lisa Dunn, lisaslac.stanford.edu)
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SSRL Headlines is published electronically monthly to inform SSRL users, sponsors and other interested people about happenings at SSRL. SSRL is a national synchrotron user facility operated by Stanford University for the U.S. Department of Energy Office of Basic Energy Sciences. Additional support for the structural biology program is provided by the DOE Office of Biological and Environmental Research, the NIH National Center for Research Resources and the NIH Institute for General Medical Sciences. Additional information about SSRL and its operation and schedules is available from the SSRL WWW site: http://www-ssrl.slac.stanford.edu/
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