April 2009 Archives

The Advanced Photon Source (APS) and APS Users Organization has announced that the 2009 Arthur H. Compton Award has been presented jointly to Simon Mochrie, Mark Sutton, and Gerhard Grubel for their pioneering efforts in X-ray photon correlation spectroscopy (XPCS), which exploits the coherent properties of synchrotron X-rays to study the slow dynamics of condensed matter at short length scales. For more information on their pioneering work, see the paper, "Observation of speckle by diffraction with coherent X-rays", M. Sutton, S. G. J. Mochrie, T. Greytak, S. E. Nagler, L. E. Berman, G. A. Held, and G. B. Stephenson, Nature 352, 608-610 (1991). Former recipients of this award are: Andrzej Joachimiak and Gerold Rosenbaum (2007); Gunter Schmahl and Janos Kirz (2005); Martin Blume, Doon Gibbs, Kazumichi Namikawa, Denis McWhan (2003); Wayne A. Hendrickson (2001); Sunil K. Sinha (2000); Donald H. Bilderback, Andreas K. Freund, Gordon S. Knapp, Dennis M. Mills (1998); Philip M. Platzman, Peter M. Eisenberger (1997); Nikolai Vinokurov, Klaus Halbach (1995).

Spider silk is a tough yet light material, but recently it has been found that it becomes three times stronger by adding small amounts of metal such as Zn, Ti and Al. The idea was inspired by research which established that trace metals are frequently found in the toughest parts of some insect bodies. Bio-materials scientists think that such metals could be incorporated in the protein structures and lead to unusual mechanical properties. Dr. M. Knez (Max Planck Institute of Microstructure Physics, Halle, Germany) and his colleagues have succeeded in infiltrating Zn, Ti and Al by the application of atomic layer deposition technique. X-ray fluorescence spectra provided the evidence for them. For more information, see the paper, "Greatly Increased Toughness of Infiltrated Spider Silk", S-Mo Lee et al., Science, 324, 488-492 (2009).

Xradia, Inc., a developer and manufacturer of ultra-high-resolution 3D X-ray imaging systems, has announced that its scanner was used by researchers at The University of Texas at Austin in the examination of fossil Lucy, the world's most famous ancient human ancestor fossil that dates back 3.2 million years. The company's Xradia MicroXCT^TM scanner, a 3D X-ray computed tomography system with sub-micron resolution, was used to scan selected pieces of the fossil, and the resulting data will assist in their studies to learn how Lucy's skeleton supported her movement and posture, and how it compares to modern humans and apes. Lucy is currently on loan from the Ethiopian Government and on tour in the U.S. as part of a world premiere exhibit organized by the Houston Museum of Natural Science. For further information, visit the web page, http://xradia.com

At the U.S. Department of Energy's SLAC National Accelerator Laboratory, scientists have observed the first beam generated by the hard X-ray laser. The Linac Coherent Light Source (LCLS) now supplies 1.5 Å wavelength coherent hard X-ray ultra short pulses with 100 femtosecond duration. Unlike conventional lasers, which use mirrored cavities to amplify light, the LCLS is a free-electron laser, creating light using free-flying electrons in a vacuum. The LCLS uses the final third of SLAC's two-mile linear accelerator to drive electrons to high energy and through an array of undulator magnets that steer the electrons rapidly back and forth, generating a brilliant beam of coordinated X-rays. LCLS scientists used only 12 of an eventual 33 undulator magnets to generate the facility's first laser light. It is the first time that an X-ray laser has operated at such short wavelengths in the truly hard X-ray region, with such brightness and short pulses. The laser paves the way to a new way of looking at not only the structure of matter but also its dynamics. By using laser pulses of less than 100 femtosecond duration, the dynamics of chemical reactions can be caught in process, and even single molecules can be imaged. For further information, see the facility's Web page, http://home.slac.stanford.edu/pressreleases/2009/20090421.htm In Science Now Daily News, Adrian Cho wrote a comprehensive article, http://sciencenow.sciencemag.org/cgi/content/full/2009/421/2

In Issue 4, vol. 8 (2009) of Nature Materials, the Insight section features a compilation of articles on recent electron and X-ray microscopy. The aim is to illustrate what are the most outstanding capabilities of modern imaging techniques based on electrons and X-ray photons, which have been often treated separately. The 6 articles in the compilation are as follows: "Is science prepared for atomic-resolution electron microscopy?", Knut W. Urban (p.260-262); "Structure and bonding at the atomic scale by scanning transmission electron microscopy", David A. Muller (p.263-270); "Electron tomography and holography in materials science", Paul A. Midgley & Rafal E. Dunin-Borkowski (p.271-280); "Near-edge X-ray absorption fine-structure microscopy of organic and magnetic materials", Harald Ade & Herman Stoll (p.281-290); "Coherent X-ray diffraction imaging of strain at the nanoscale" Ian Robinson & Ross Harder (p.291-298); "X-ray imaging beyond the limits", Henry N. Chapman (p.299-301). Visit the Web page to download the full Insight as PDF file (4.77MB), http://www.nature.com/nmat/journal/v8/n4/pdf/nmat-insight-microscopy.pdf