Contents of this Issue:
1. Science Highlight — Imaging of Biochemical Transformation of Arsenic in Plants
(contacts: I.J. Pickering, email@example.com; G.N. George, firstname.lastname@example.org)
The toxicity of arsenic is widely known, but perhaps less widely appreciated is that its level of toxicity critically depends on the chemical form. The fern Pteris vittata is one of a small group of plants that actively accumulates arsenic to a startling degree - an arsenic hyperaccumulator. P. vittata absorbs arsenic from soil, typically present as the relatively benign arsenate, and changes its chemical form to arsenite, which is one of the more toxic kinds of arsenic. The plant thrives on this toxic regimen, and it most likely does this to defend itself from hungry herbivores. The ability of P. vittata to take up arsenic has generated much excitement because of potential applications for environmental cleanup of drinking water and of contaminated sites.
2. Science Highlight — Shedding Light on Cheaper Communication
(contact: J.P. Chang, email@example.com)
By doping 8 atom% ionic Er into yttrium oxide (Y2O3) thin films by atomic layer deposition, the Er ions remain sufficiently distant from each other to retain their photoluminescent properties. This percentage also assures that enough Er is incorporated into the thin film to have a strong amplifying effect.
The results of this study are published in Journal of Applied Physics. (T.T.
Van, Bargar, J.R., and Chang, J.P. (2006) Structural investigation of Er
coordination in Y2O3. J. Applied Physics
100, 023115). To learn more about this research see the full technical
3. Vote for the 2007 SSRLUO Executive Committee, Participate in SSRL33, and Attend the Next SSRLUOEC Meeting on October 13
(contacts: J. Andrews, SSRLUOEC Chair, firstname.lastname@example.org; C. Kim, SSRLUOEC Vice-Chair, email@example.com)
Voting to fill five open positions on the SSRL Users' Organization Executive
Committee (SSRLUOEC) is now underway. Having a full and engaged committee is
essential in a time of considerable change, continued funding concerns, and an
increased desire on the part of SSRL for user feedback in defining its future
vision and direction. So, please take a few minutes before noon on October 12
to cast your ballot. SSRLUOEC representatives will be elected by the SSRL user
community by majority vote, and the results will be announced during the SSRL
Users' Meeting Awards Dinner on October 12. Vote at:
Several joint SSRL-ALS workshops are being held on October 11 in conjunction with the meeting, including:
4. Adrian Cavalieri and David Fritz Share 2006 W.E. Spicer Young Investigator Award
The Stanford Synchrotron Radiation Laboratory (SSRL) and the SSRL Users'
Organization are pleased to announce that Adrian L. Cavalieri and David M.
Fritz have been chosen to receive the 2006 William E. Spicer Young Investigator
Award. The joint award, which consists of a plaque plus the shared $1,000
prize, will be presented at the 33rd Annual SSRL Users' Meeting awards dinner
on Thursday, October 12, 2006. The following day, during the Young
Investigators' Session, Drs. Cavalieri and Fritz will deliver presentations
about their work: Clocking Femtosecond X-rays (A. Cavalieri) and Mapping the
Excited State Potential Energy Surface of Bismuth (D. Fritz).
Although they have just begun their professional careers, Adrian Cavalieri and David Fritz have contributed greatly to synchrotron research. They have worked on many revolutionary experiments and have authored or co-authored several peer-reviewed publications in prestigious journals.
5. SSRL and Rocky Flats Plutonium Remediation
(contact: D.L. Clark, LANL)
The Rocky Flats Environmental Technology Site (RFETS) is an environmental cleanup site located about 16 miles northwest of downtown Denver. Soils at RFETS are contaminated with actinide elements (Uranium, Plutonium, Americium) from improper storage of contaminated solvents and site operations. Until December 1989, the Rocky Flats Plant made components for nuclear weapons using various radioactive and hazardous materials, including plutonium, uranium and beryllium. In 1995 the site was designated an EPA Superfund cleanup site.
The DOE originally estimated site clean-up would cost $37 billion and take nearly 70 years. Independent contractor Kaiser-Hill and the DOE, working in close coordination with Rocky Flats stakeholders, devised an aggressive plan to complete the cleanup and closure of Rocky Flats by 2006 at an estimated cost between $6 billion and $8 billion.
6. JCSG Deposits 300th Protein Structure
(contact: (contact: A. Deacon, firstname.lastname@example.org)
The JCSG is a collaboration between researchers at the University of California San Diego, the Burnham Institute, The Scripps Research Institute, the Genomics Institute of the Novartis Research Foundation and Stanford Synchrotron Radiation Laboratory (see http://www.jcsg.org for more details).
7. BL 5-1/2: SSRL's Newest Soft X-ray Beam Line Now Open for Users
(contact for BL5-1: H. Ogasawara, email@example.com;
contact for BL5-2: J. Luning, firstname.lastname@example.org)
A new, state-of-the-art spherical grating monochromator, covering the photon energy range from 150 eV to 1,200 eV, is now operational at Beam Line 5 using the existing 26-period elliptically polarizing undulator as source. This monochromator serves two branch lines, which are equipped with dedicated end stations for soft x-ray spectroscopy (BL 5-1) and soft x-ray small angle scattering (BL 5-2).
The spectroscopy branch line (5-1) uses K-B mirrors to focus the beam to a vertical spot size of 10 microns rms and horizontally to 75 microns rms. The end station is designed for surface and solid state experiments with ultra-high vacuum compatible samples up to 10 mm in diameter. The main chamber has an electron spectrometer (SES-100, VG-Scienta) for photoemission spectroscopy and partial electron yield detector for X-ray absorption spectroscopy. A horizontally mounted manipulator is provided for experiments with a minimum sample temperature of about 40 K. The manipulator transfers samples between the preparation chamber and the main chamber. Sputtering facilities, mass spectrometer and LEED optics are available in the preparation chamber. Gas dosing facilities and ports for evaporation sources are also available. Evaporation sources can be replaced without venting the preparation chamber. A second manipulator is also mounted vertically on the main chamber for transferring samples from a second preparation chamber with more limited facilities.
The second branch line (5-2) is tailored for resonant scattering of soft x-rays to study order phenomena on the nanometer length scale and their dynamics like chemical segregation in polymer blends or spin dynamics in magnetic nanostructures. Possible experimental techniques include 'small' angle scattering in transmission (theta < 20°) or reflection geometry (2 theta < 20°), scattering of coherent x-rays for lensless microscopy, x-ray photon correlation spectroscopy, and time resolved scattering by synchronizing an external pump with SPEAR3's bunch structure. The main detector is an in-vacuum direct illumination CCD with 1300x1340 pixels from Princeton Instruments, which can be replaced with a position sensitive multi-channel plate detector from Quantar Technologies. The beam line optics demagnify the source by about 3:1, yielding a divergence of 400 µrad in both, the horizontal and vertical plane. The inherent transverse coherence length of the x-ray beam is a few micrometers, which can be increased to several tens of micrometers by reducing the source divergence with apertures.
Users interested in submitting proposals for experiments on the new beam lines
are reminded that the deadline is November 1.
8. BL 2-3 Hard X-ray Microprobe Ready for Users
(contact: S. Webb, email@example.com)
We are pleased to announce the availability of a new microprobe system for SSRL users on BL2-3. Ongoing commissioning of the equipment progressed over the last year, with successful data collected by user commissioning runs at the end of July 2006. The facility produces a 2 micron spot having 5x107 to 108 photons/sec. Experimental capabilities include x-ray fluorescence mapping and micro x-ray absorption spectroscopy. This facility is optimized for the energy range 15 to 23 keV, but it can be used at lower energies as well. Additional equipment (new fluorescence detectors, CCD diffraction area detector, cryogenic sample stage) will be installed and commissioned during the 2007 run. User requests for beam time at the hard x-ray microprobe will be scheduled in consecutive blocks.
If you are interested in submitting new proposals for microprobe experiments at BL2-3, remember that new X-ray/VUV proposals are due by November 1. Users with active proposals can request microprobe beam time for the next scheduling period by submitting a beam time request by the December 1 deadline (be sure to denote the microprobe setup in your equipment request). Contact Sam Webb with questions about the microprobe equipment, sample preparation, or data analysis. http://www-ssrl.slac.stanford.edu/users/user_admin/deadlines.html
9. New Text Book on Magnetism by SSRL Authors Highlights the Use of X-rays
The synchrotron radiation community is well familiar with the dramatic developments in x-ray sources and science over the last fifteen years or so. Similarly, one of the oldest fields of physics, magnetism, has seen a spectacular recent advance. The giant magnetoresistance effect, discovered in 1988, is now used in every computer hard drive and has ushered in the age of "spintronics"- the use of the electron spin to sense, carry or manipulate information. This revolution forms the backdrop for the newly published textbook by SSRL physicists J. Stöhr and H. C. Siegmann. The book, "Magnetism, from Fundamentals to Nanoscale Dynamics," published by Springer Verlag as Volume152 in its Series in Solid State Sciences, grew from a proposed 400-page manuscript to an 820-page textbook. Written over five years, "Magnetism" is intended for late undergraduate and graduate students, academics, and scientists in research laboratories.
More generally, the book gives a comprehensive account of magnetism's historical development, its physical foundations and the continuing research in the field. It covers both the classical and quantum mechanical aspects of magnetism as well as novel experimental techniques. It also highlights the scientific paradigm shift and technological revolution based on "spintronics" and ultrafast magnetization dynamics and how these developments are applied to magnetic storage and memory.
The authors would like to acknowledge weekly meetings and brainstorming sessions with SSRL and ALS scientists, input from industrial colleagues and support from the Office of Basic Energy Sciences of DOE.
Magnetism: From Fundamentals to Nanoscale Dynamics
Springer Series in Solid-State Sciences 152
Joachim Stöhr and Hans Christoph Siegmann
820 pages, 325 illustrations, hardcover
10. SSRL Footage Included in History Channel Special on Ink
"Invented by the Chinese in about 3000 BC, it spread the word of God and war. It set us free and spelled out our rights. It tells stories, sells products and solves crimes. It's ink and it's everywhere! From squid to soybeans, from ancient text to awesome tattoos, join us as we dip into the well for the scoop on ink." - History Channel
This upcoming feature, airing on Wednesday, October 4 (6 pm/10 pm) includes footage of work on the Archimedes Palimpsest experiment in late July on BL6-2. (http://www-ssrl.slac.stanford.edu/research/archimedes_summary.html) Check your local listings for the exact time in your area for this Modern Marvels documentary on ink.
11. Important Upcoming Deadlines
(contacts: C. Knotts, firstname.lastname@example.org; L. Dunn, email@example.com)
A number of positions are currently available at the LCLS, LUSI and SSRL.
Please refer to the Photon Science Job Openings page for more information about
these job opportunities.
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.
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