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Last Updated: | 29 SEP 2003 |
| Content Owner: | L. Dunn | |
| Page Editor: | L. Dunn |
**** **** **** * * * * * * **** **** **** * * * * * * **** **** * * **** HEADLINES - a digital monthly publication
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Contents of this Issue:
1. Science Highlight — Synchrotron
Mesodiffraction: A Tool for Understanding Turbine Engine Foreign Object Damage
(contact: Brad Boyce, Sandia Laboratories)
Aircraft turbine engines are prone to ingesting pebbles and other debris that can damage jet engine fan blades, dramatically reducing the longevity of the components - sometimes catastrophically. Failures associated with such "foreign object damage" cost the aerospace industry an estimated $4 billion a year. Studies at SSRL have helped show how and why fan blades - which normally experience significant stresses during flying - fatigue sooner than expected from foreign object damage. Brad Boyce of Sandia National Laboratories, Apurva Mehta of SSRL and their collaborators simulated the damage by firing small steel balls onto a titanium alloy commonly used in fan blades. They examined the resulting damage with the unique abilities of synchrotron mesodiffraction (x-ray diffraction in the sub-millimeter scale, in this case 0.3 mm to match the size scale of the damage).
The team made spatial maps showing the magnitude and distribution of residual stresses from the damage, as well as maps of the corresponding elastic and plastic strains (a measure of the degree of deformation). The measurements also demonstrated the validity and limitations of calculations that engineers have been using to estimate the residual stress state. This new understanding has been incorporated into a mathematical model of failure to help design new blades to prevent failures from foreign object damage. This example illustrates the utility of a synchrotron x-ray source to solve real-world engineering problems.
For more information on this work see:
http://www-ssrl.slac.stanford.edu/research/highlights_archive/fod.html
or http://www-ssrl.slac.stanford.edu/research/highlights_archive/fod.pdf
(see also: SSRL workshop on "Probing Mechanical Deformation and Failure via Synchrotron X-rays" at http://www-ssrl.slac.stanford.edu/conferences/ssrl30/workshops.html)
2. 30th Annual SSRL Users' Meeting and Workshops
-- October 8-10, 2003
There is still time to register for SSRL's Annual Users' Meeting and workshops
to be held on October 8-10, 2003. Meeting sessions will focus on
interdisciplinary applications of small angle x-ray scattering, macromolecular
crystallography, microspectroscopy and diffraction, and surface spectroscopy.
The Users' Meeting provides a forum for the presentation and discussion of
research activities from SSRL and the synchrotron community. Additional
information about the meeting and workshops can be found at:
http://www-ssrl.slac.stanford.edu/conferences/ssrl30/
3. SSRL Faculty Awarded Prestigious Prize
Axel Brunger, professor of SSRL, Molecular & Cellular Physiology, and Neurology & Neurological Sciences at Stanford University was awarded the Gregori Aminoff Prize 2003 during a ceremony in Stockholm on September 10. The Aminoff Prize is awarded annually by the Royal Swedish Academy of Sciences for pioneering work in crystallography, with preference "shown for work evincing elegance in the approach to the problem". Prof. Brunger, who shares this year's award with Prof. T. Alwyn Jones, Uppsala University, Sweden, was cited "for his development of refinement techniques for macromolecules". The award is in memory of Gregori Aminoff, who introduced x-ray crystallography to Sweden and performed early structural studies of minerals.
4. SPEAR3 Installation Nears Completion
On-schedule
(contact: Tom Elioff)
As noted in last month's report, August 27 marked the installation of the last magnet raft assemblies (with associated vacuum chambers) that complete the circle of all major magnets that define the SPEAR3 ring. Work has continued this month to complete the straight sections between these magnet systems. This includes insertion devices (wigglers and undulators) which are the sources of high intensity x-ray beams for experiments. Work is also in progress re-establishing the experimental beam lines and their vacuum connections to the SPEAR ring. Three straight sections contain the special septum and kicker magnets that allow the injected beam from the booster to enter the SPEAR ring; these have been installed. The magnets of the beam channel which transport the injected beam to the septum channel have also been installed. Other diagnostic components and beam stops are near completion. Finally, the installation of bellows which vacuum-connect all of the above systems has been initiated. The cooling systems (LCW and HCW) for magnets, vacuum, and RF components are now complete. Apart from installation of these technical components, the last major contract is now in progress for the installation and connection of power, signal, and control cables for technical components within the ring, the power supply building, and the main control room.
A very successful Accelerator Readiness Review (ARR) was held on September 9-11. The required review serves to insure that all SPEAR3 systems and components meet applicable safety standards, rules, and regulations and that SPEAR3 will be safe to operate.
5. Report on "Future Possibilities of the LCLS"
(contact: Max Cornacchia)
The Task Force on "Future Possibilities of the LCLS", led by Max Cornacchia, reported on its study on Wednesday, September 24, at SLAC. After the initial operation, the capability of the SLAC linac together with the available space and infrastructure of SLAC, will allow for considerable extension of the parameters and flexibility of the baseline design. Future developments could include delivery of x-ray pulses in the one femtosecond regime, extension of the spectral range, increase of the FEL power, exploitation of the spontaneous emission, and a more flexible time structure. As this potential is exploited, the LCLS will remain a world leading instrument for many years beyond its commissioning in FY2008 and operation as the world's first x-ray free-electron laser. A report on these opportunities is being issued.
6. Delegation from the UK Biotechnology and
Biological Sciences Research Council Visits SSRL
(contact: Keith Hodgson)
On Thursday, September 11, SSRL hosted a visiting delegation from the Biotechnology and Biological Sciences Research Council in the UK. The delegation, led by Prof. Julia Goodfellow, Chief Executive, included several members from the Council staff and representatives from the British Consulate. The goal of the visit was to share information on BBSRC's 10-year vision and strategic plan as it related to structural biology and genomics and discuss areas of cooperation. The visit began with a lunch and discussion attended by SSRL faculty and senior management. The group heard an overview presentation of SSRL by Keith Hodgson and a presentation by Ashley Deacon on the structural genomics activities (JCSG) in which SSRL has the lead role for structure determination. The group then had a tour of the experimental hall and SPEAR3, focusing on the macromolecular crystallography beam lines. Afterward, they departed for campus to visit the new Clark Center and discuss the Bio-X program.
7. SSRL Projects Presented at SRI-03
The Eighth International Conference on Synchrotron Radiation Instrumentation (SRI-03) took place in San Francisco on August 25-29. Hosted jointly by the Advanced Light Source and SSRL, the conference attracted more than 750 attendees to discuss the current state-of-the-art of synchrotron experimentation. 56 talks and over 600 posters were presented, covering new sources, new optics, new detectors, and new scientific techniques. The ultrafast x-ray sources being developed by SSRL at SLAC received much attention. Jerry Hastings gave a plenary talk on X-ray Free-Electron Lasers such as the Linac Coherent Light Source (LCLS), and John Arthur gave an invited talk on the recent commissioning of the Sub-Picosecond Pulse Source (SPPS). A related plenary talk by Phil Bucksbaum gave an overview of ultrafast science and techniques using x-rays.
Additional SSRL science was presented by Jan Lüning, who gave an invited talk on coherent resonant x-ray scattering from magnetic domains and by a number of SSRL staff and users who presented posters. The conference proceedings will be published by the American Institute of Physics.
8. SMB Summer School Well Received
(contacts: Hiro Tsuruta; Serena George; Ana Gonzalez)
The third in a series of structural molecular biology (SMB) summer schools was held at SSRL from September 16-19. The school focused on three synchrotron-based techniques: small angle x-ray scattering, x-ray absorption spectroscopy, and macromolecular crystallography, and the application of these techniques to biological problems. The summer school opened with a general introduction to synchrotron radiation given by Keith Hodgson. It was followed by two days of lectures that provided an introduction to each of the three techniques, as well as covering basic theory, experimental considerations, and scientific applications. The lecture portion was followed by a day and a half of rotating practical sessions, giving the students hands-on experience in data collection and analysis. This year's summer school was attended by 19 students (representing 6 U.S. states, Canada, and the U.K.) and was led by a team of 15 tutors (who are internationally recognized experts in their field). It provided a relaxed forum for interaction between the students and tutors and was enthusiastically received by the participants. These summer schools are an important component of the training and dissemination component of the NIH NCRR program grant that supports a significant part of the structural biology user program at SSRL.
9. Free-electron Laser Conference Held in Tsukuba,
Japan
(contact: Max Cornacchia)
The 25th International Free Electron Laser Conference was held in Tsukuba, Japan, and was attended by five representatives from SLAC. The subject matter was very relevant to the development and design on the Linac Coherent Light Source (LCLS). Max Cornacchia gave an "Update on the LCLS", while Dave Dowell talked on 'A two-frequency rf photocathode gun', which was received with considerable interest. Zhirong Huang gave an overview of the several possibilities to generate femtosecond and sub-femtosecond x-ray pulses. Many good ideas were proposed, and some are ripe for experimental investigations. In particular, the SLAC proposal to select a sub-femtosecond slice of an electron bunch for lasing (with consequent creation of a sub-femtosecond FEL pulse) was very well received by several participants. Patrick Krejcik reported on the initial results of the Sub-Picosecond-Photon-Source (SPPS).
The Free-Electron Lasers Conference Organizing Committee confirmed the choice of SLAC as the conference site in 2005. In 2004, the meeting will be held in Trieste.
10. Plan Ahead for Beam Time in 2004
A Call for Proposals is being distributed inviting users to submit proposals
for X-ray and VUV experiments before November 1, 2003, and for Macromolecular
Crystallography before December 1, 2003. Beam time eligibility for new
X-ray/VUV proposals begins in April 2004 and March 2004 for macromolecular
crystallography proposals. For more information on proposal submission see:
http://www-ssrl.slac.stanford.edu/users/user_admin/guide.html
We expect that beam will be available for regular user scheduling on most beam lines in March 2004. Users with existing proposals who wish to request beam during this time frame (including the possibility of some commissioning time in February), can submit a beam time request by November 17, 2003 for X-ray/VUV beam lines or by January 21, 2003 for Macromolecular Crystallography beam lines. Please note that these projections are dependent upon completion of upgrade activities and radiation shielding, and that beam stability early in the run will be difficult to predict.
11. SSRL-Related User Publications Requested
Let us know whenever SSRL-related work is published in a scientific journal or conference proceedings, a Ph.D. thesis is completed, or a patent based on work done at SSRL is received. Updated information on all SSRL-related publications is extremely important to us as publications are a key measure of productivity and a metric that impacts our facility's funding. If you are not sure if we have listed your recent publications, check out the listings on our website: http://www-ssrl.slac.stanford.edu/pubs/.
To add publications, please contact Lisa Dunn or fill out the web form: http://smb.slac.stanford.edu/admin/form_publication.html
Also, you may have noticed that each month we feature user science in this electronic newsletter, and archives of past scientific highlights are listed on our website. Many of these stories have been included in reports to funding agencies and have been picked up by other media, so we encourage users to remember to keep us in the loop when exciting results are about to be published. We can work with users and the SLAC Office of Communication to develop the story and ensure that the authors have the opportunity to review the drafts. Most importantly, we want to work with users to communicate their research findings and accomplishments to a much broader audience.
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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 S ciences. Additional information about SSRL and its operation and schedules is available from the SSRL WWW site.
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