Vol. 14, No. 5 - November/December 2013
From the Director
We've reached the end of another exciting year at SSRL and are getting ready for the winter break. The 2013 run was very successful with an excellent average uptime, and at a 500 mA current in SPEAR3 beginning early in the calendar year. I would like to offer my thanks to the outstanding SSRL staff for their hard work in continuing to keep SSRL at the forefront, and our users for performing such excellent science using our very diverse beam line facilities. Thanks also goes to our funding agencies for their support in enabling SSRL to serve the science community. As we look forward to 2014, we will be laying the foundations for more exciting developments, both for the accelerator, and for new beam lines.
Best wishes for a wonderful holiday filled with joy, peace and prosperity in the New Year.
Percolation Explains How Earth’s Iron Core Formed – Contact: Wendy Mao, Stanford University
Earth’s inner structure is organized into layers. The outermost crust overlays the mantle, which, in turn, surrounds our planet’s core. The crust and mantle are mainly composed of silicate rocks. In contrast, Earth’s core is metallic, containing predominantly iron. But how did iron separate from the silicates in order to form the metallic core during Earth’s evolution? Researchers have recently provided evidence that the percolation of liquid iron alloys through a solid silicate matrix can explain the formation of Earth’s core. Read more...
Using r-Space Phase Information in EXAFS to Characterize Possible Off-center Displacements in PbTe – Contact: Frank Bridges, University of California Santa Cruz
Lead telluride, PbTe, is a well-known material used for its thermoelectric characteristics. In 2010, a research study suggested a new property: At temperatures above 100 K, the Pb atoms may become displaced from their usual locations in the crystal lattice (0.2 Å at 300 K), inducing Pb-Te electric dipoles in the material. The proposal came as a surprise because temperature-induced electric dipoles, which may cause ferroelectricity in materials, are known to only form at low temperatures but not upon heating. Researchers have now set the record straight. In a recent x-ray study they found no evidence of high-temperature-induced dipoles, challenging earlier suggestions. Read more...
Direct Observation of the Oxygenated Species during Oxygen Reduction on a Platinum Fuel Cell Cathode – Contact: Hirohito Ogasawara, Stanford Synchrotron Radiation Laboratory
Polymer-electrolyte-membrane (PEM) fuel cells are potential candidates for the environmentally friendly and cost-efficient production of renewable energy from hydrogen and oxygen. At the fuel cell’s anode, hydrogen gas is split into protons, which subsequently combine with oxygen gas at the cathode to produce water. However, current PEM fuel cells are limited in their efficiency by the occurrence of several competing oxygenated intermediates at the cathode. A research team has now shed light on the interplay between different oxygenated species and fuel-cell performance. Read more...
Updates and Announcements
New Undulators Prep SSRL for Powerful Beam Lines
New equipment installed during our recent 3-month shutdown has set the stage for two powerful new beam lines, and enabled a third beam line to return to full strength.
In addition to various upgrades, fixes and general maintenance projects, SSRL staff installed new undulators for Beam Lines 5 and 15. An undulator is a carefully configured series of magnets; when electrons orbiting the SPEAR3 storage ring go through an undulator, they zig-zag between the magnets and emit bright, high-quality x-rays for specialized experiments.
One new undulator will produce elliptically polarized x-rays for Beam Line 5-2, which is under construction and scheduled to be available to users soon. Donghui Lu, who heads the soft x-ray group in SSRL's Material Sciences division, explained the new capabilities it will provide.
"It gives us full control of the polarization of the x-rays," he said. This means the x-ray light waves sent to the BL5-2 end station can be polarized in a specific direction – for example, the waves all line up horizontally or vertically – or they can be polarized with a specific "handedness," traveling in clockwise or counter-clockwise circles. Using these polarized x-rays with a technique called angle-resolved photoemission spectroscopy, or ARPES, researchers can learn about properties of complex materials.
"One type of material we'll use BL5-2 to study is high-temperature superconductors," Lu said. These materials, which conduct electricity without resistance at temperatures considerably above absolute zero, are a major focus of research because of their promise for improving energy efficiency, but how they do it is still a puzzle. Read more...
We'd like to thank Stosh Kozimor from the Los Alamos National Laboratory for agreeing to serve as Vice-Chair on SSRL's Users' Organization Executive Committee this year. As Vice-Chair he will serve on the organizing committee and co-chair our next Annual Users' Meeting along with SSRL scientist Joanna Nelson Weker and two representatives for the LCLS. Initial planning for the 2014 Users' Meeting begins with setting the best dates for the user community. Your input is appreciated and we have set up a poll for users to indicate their date preferences.
New Traffic Training Requirement for Staff and Users
All badged staff at SLAC – employees, contractors, users, etc., are now required to take new SLAC Traffic Safety Training (course 154) by January 15, 2014. This training is provided to ensure driver responsibilities and traffic safety information is being consistently provided and to eliminate currently required forms. Traffic safety, access gate use information and site driving requirements have been removed from orientation courses and are now consolidated into this short online course. SSRL users please log into the SLAC web-based training site to take this training. Please contact User Admin if you require login information. Read more...
Getting through Gate 17
Automated access is now in operation 24/7 at Gate 17 and the Sector 30 Gate. Avoid delays by contacting us before arriving and allowing extra time for badging/check-in. Initially, the process is likely to take longer as we make the transition to the new system.
If you have current safety training and an activated proximity card, your card will open the automated gate. Proceed to User Research Administration (URA) in Building 120 for check-in. If you have already been issued a badge with a proximity access chip, please contact User Administration if your access needs to be extended for your next scheduled set of shifts.
However, you will need to first stop at SLAC Security IF you are a first-time user, don't have a proximity ID card, have incomplete or expired safety training. After showing the guard your photo ID at the Main Gate, turn right and then make another immediate right to enter the SLAC Security Office (Building 235). Security will issue a temporary card after confirming that your training is current and that you are listed on a scheduled proposal. Use the temporary card to enter Gate 17 and proceed to URA in Building 120 for check-in.
New Temporary Food Service
The SLAC Cafe, auditorium and visitor center have been closed and will be replaced with a new Science and User Support Building (SUSB). During this construction (2013-2015), temporary food service will be provided by the Cardinal Chef Mobile Gourmet food trucks, 11am - 2pm in front of SLAC Building 27. Lunch menus are posted online.
User Research Administration
AAAS Symposium: U.S. National User Facilities, a Major Force for Discovery and Innovation (February 15, 2014)
The National User Facility Organization (NUFO) is partnering with the DOE Office of Science and the National Science Foundation (NSF) to sponsor a symposium at the 2014 AAAS meeting in Chicago. The symposium, America's National User Facilities, a Major Force for Discovery and Innovation, will be held 8:30-11:30 am on Saturday, February 15, 2 014 in the Hyatt Regency Hotel. Please inform your colleagues and plan to participate to help raise awareness about the benefits of using our facilities.
America's national scientific user facilities provide unique capabilities, instrumentation, and expertise annually to approximately 50,000 scientists and engineers from academia, government, and industry. For many of these individuals, a user facility is their laboratory—their primary platform for experimental research—and they gain access to these unique tools through peer-reviewed proposals. Much of the research is basic (discovery) research, but the rich interdisciplinary environment promotes interactions among scientists from diverse fields, institutional types, and countries to facilitate the translation of these discovery findings into solutions to real-world problems. This symposium will provide an overview of the capabilities offered by these national facilities, and will highlight outstanding recent examples of discovery and innovation stemming from work at these user facilities, including the development of energy-harvesting “solar shingles,” the discovery of the structure of key biological molecules, the development of new drugs, and the discovery and the contributions to our understanding of fundamental science.
The symposium will conclude with presentations by the major federal sponsors of the user facilities with reserved time for discussion of the policy challenges facing this key facet of America's scientific enterprise now and into the future. The speakers are Eric Isaacs (Director Argonne National Laboratory and soon-to-be Provost of The University of Chicago), Roger Falcone (Director Advanced Light Source at LBNL), Stephen Wasserman (Senior Research Fellow, Eli Lilly and Company), Eric Gawiser (Associate Professor, Department of Physics and Astronomy, Rutgers University), Patricia Dehmer (Deputy Director for Science Programs, Office of Science, DOE), and F. Fleming Crim (Assistant Director for Mathematics and Physical Sciences, NSF).
The Stanford Synchrotron Radiation Lightsource (SSRL) is a third-generation light source producing extremely bright x-rays for basic and applied research. SSRL attracts and supports scientists from around the world who use its state-of-the-art capabilities to make discoveries that benefit society. SSRL, a U.S. DOE Office of Science national user facility, is a Directorate of SLAC National Accelerator Laboratory, operated by Stanford University for the U.S. Department of Energy Office of Science. The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research, and by the National Institutes of Health, National Institute of General Medical Sciences. For more information about SSRL science, operations and schedules, visit http://www-ssrl.slac.stanford.edu.
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Questions? Comments? Contact Lisa Dunn