As of May 31, 2010

for international journal X-Ray Spectrometry (John Wiley & Sons Ltd.)

Laser-based femtosecond X-ray pulse source (May 27, 2010)

A Chinese group led by Professor J. Zhang (President of Shanghai Jiao Tong University) recently published a report on the generation of X-ray pulses of around 3 keV by using an Ar clustering gas jet target (~3mm dia.) and a Ti:sapphire laser (power 800 mJ, pulse width 28 fs, wavelength 800 nm, frequency 10 Hz).  The intensity of the Ar K-shell emissions in the forward direction was found to be around 10⁴ photons/mrad²/pulse.  The group emphasized the significance of laser contrast, which is a ratio of the main pulse and pre-pulse, and found that X-ray flux is reduced by 2 orders of magnitude if the laser pulse contrast decreases from 10⁹ to 10⁷ with constant laser pulse energy. For more information, see the paper, "Intense High-Contrast Femtosecond K-Shell X-Ray Source from Laser-Driven Ar Clusters", L. M. Chen et al., Phys. Rev. Lett. 104, 215004 (2010).

Synchrotron X-ray fluorescence imaging of a 150 million year old dinobird (May 18, 2010)

An international team of paleontologists, geochemists and physicists led by Dr. R. A. Wogelius (University of Manchester, UK) recently employed X-ray fluorescence imaging to analyze a 150 million year old fossil of Archaeopteryx, which had dinosaur-like teeth and bird-like feathers.  For many years, it was believed that the fossil contained nothing but bone and rock.  However, the use of a brilliant synchrotron X-ray beam enabled the detection of chemical elements hidden within.  It was found that the fossil still had elemental compositions that were completely different from the embedding geological matrix.  The researchers completed the chemical map of the dinobird for 12 elements for the first time.  Some phosphor and sulfur were found in soft tissue, as well as trace zinc and copper in bone.  The experiment was done at wiggler beam line 6-2 at Stanford Synchrotron Radiation Lightsource (SSRL, California, USA).  For more information, see the paper, "Archaeopteryx feathers and bone chemistry fully revealed via synchrotron imaging", U. Bergmann et al., Proc. Nat. Aca. Sci., 107, 9060 (2010).

X-ray studies on surface ordering in cold liquids (May 17, 2010)

Professor P. Dutta (University of Chicago) and his colleagues recently clarified that the surface density profile acquires layered structures at 0.2 T_c; T_c is the liquid-gas critical temperature.  The present research was for dielectric liquids, pentaphenyl trimethyl trisiloxane, and pentavinyl pentamethyl cyclopentasiloxane. The X-ray reflectivity technique was employed to determine the surface profile experimentally.  The research group had previously found similar phenomena for other liquid dielectric liquids as well as liquid metals.  The present studies could strengthen their series of work.  For more information, see the paper, "Surface order in cold liquids: X-ray reflectivity studies of dielectric liquids and comparison to liquid metals", S. Chattopadhyay et al., Phys. Rev, B81, 184206 (2010).
 

Atomic-resolution element mapping by combination of energy-dispersive X-ray detector and aberration-correction electron microscope (May 11, 2010)

Dr. C. H. Chen (National Taiwan University, Taiwan) and his colleagues recently published a report on ultra high resolution element mapping.  The research group employed a scanning transmission electron microscope (STEM) with specially enhanced spherical aberration correction.  The beam size was nearly 1 Å.  A silicon drift detector (Bruker XFlash-5030) was employed and set with a solid angle of 0.13 steradian.  The group studied InGaAs/InAlAs superlattices, and discussed the 1.47 Å dumbbell structure using both structural imaging and mapping of characteristic X-rays (In L, Ga K and As K).  For more information, see the paper, "Emergent Chemical Mapping at Atomic-Column Resolution by Energy-Dispersive X-Ray Spectroscopy in an Aberration-Corrected Electron Microscope", M.-W. Chu et al., Phys. Rev. Lett. 104, 196101 (2010).
 

Efficient XRD analysis of combinatorial libraries (May 5, 2010)

Combinatorial materials synthesis is a promising new way of developing and finding novel functional materials.  By the use of sophisticated thin film technology, it is possible to create compositionally graded samples on the same single substrate.  To analyze this combinatorial library, some novel technique is required.  A UK research group led by Professor K. D. Rogers (Cranfield University, UK) recently reported on high-throughput data collection and analysis using an X-ray diffraction (XRD) probe.  In the research, an extended X-ray beam was used to illuminate the libraries, and a large area detector was used to collect the data.  A new algorithm was employed to analyze the collected data and extract the crystallographic information.  For more information, see the paper, "High Throughput X-ray Diffraction Analysis of Combinatorial Polycrystalline Thin Film Libraries", S. Roncallo et al., Anal. Chem., 82, 4564 (2010).
 

Coherent X-ray diffraction imaging of weak phase object by using a high aspect ratio aperture (April 27, 2010)

Coherent X-ray diffraction imaging is one of the hottest research topics in advanced X-ray physics.  The method reconstructs a real-space image from an oversampled diffraction signal by using computer algorithms instead of lenses.  So far, its application has been limited to fairly strong phase objects, mainly due to parasitic scattering from the optics used for limiting the beam.  Korean researchers recently published an interesting report on its application to a nonisolated weak phase object, a one-dimensional trench structure fabricated on a Si substrate.  In their discussion, the authors reported that such work was enabled by employing a special aperture with a very high aspect ratio of nearly 100 made of tantalum (1.7 μm × 2.2 μm aperture with a thickness of 130 μm).  For more information, see the paper, "Coherent hard x-ray diffractive imaging of nonisolated objects confined by an aperture", S. Kim et al., Phys. Rev. B81, 165437 (2010).
 

Hard X-ray full-field microscopy with computer tomography capability (April 20, 2010)

A group led by Professor Ch. David (Paul Scherrer Institute, Switzerland) recently developed a synchrotron-based full-field microscope, which can work with hard X-rays, typically 10 keV.  The instrument supports tomographic absorption and phase contrast imaging with a spatial resolution of 144 nm.  The researchers demonstrated phase-contrast 3D imaging of a melanocortin-3 preosteoblast cell.  For more information, see the paper, "Phase-contrast tomography at the nanoscale using hard x rays", M. Stampanoni et al., Phys. Rev. B 81, 140105(R) (2010).
 

Bragg X-ray Fourier transform holography (April 19, 2010)

Lens-less microscopy is now widely acknowledged to be an elegant solution to the so-called phase problem in X-ray crystallography.  The method is based on the digital retrieval of the phase from the object’s coherently diffracted intensity patterns, with the inversion being achieved through the use of time-consuming iterative algorithms.  Fourier transform holography is a similar technique, but is essentially very quick and straightforward.  Dr. V. Chamard (IM2NP, CNRS, Aix-Marseille Universite, France) and her colleagues recently demonstrated 3D imaging of a SiGe nanocrystal with Fourier transform holography.  One unique point of the research is that they employed Bragg geometry, rather than forward scattering geometry, to obtain full 3D information.  The technique requires that a reference crystal is placed near the object crystal to be imaged, and that the two crystals need to have comparable lattice parameters.  They were successful in determining the electron density and the displacement field in 3D without suffering convergence problems, which are often the case with lens-less imaging iterative algorithms.  For more information, see the paper, "Three-Dimensional X-Ray Fourier Transform Holography: The Bragg Case", V. Chamard et al., Phys. Rev. Lett. 104, 165501 (2010).

 

DOE approves upgrade of Advanced Photon Source, Argonne (May 3, 2010)

The Advanced Photon Source has received approval from the U.S. Department of Energy (DOE) for the first stage of an upgrade to the facility.  Details of the upgrade program can be found in a downloadable movie, http://www.aps.anl.gov/Upgrade/CDR
 

Nature Materials interviews CEO of Diamond Light Source (May 1, 2010)

In the May 2010 issue of Nature Materials, Joerg Heber interviewed Professor G. Materlik, CEO of the Diamond Light Source, UK.  The article features his answers to 7 wide-ranging questions that would be of particular interest to readers, such as "What is the future of synchrotrons?", "How about free-electron lasers?" and "Are you worried about the general science budget in the UK and about Diamond's funding?"  For more information, see the article, "Coherence comes full circle", Nature Materials 9, 375 (2010).
 

"What are X-rays?" exhibition at Kyoto University, Japan (April 28, 2010)

Kyoto University Museum is staging a special exhibition called "What are X-rays?" from April 28 to August 29.  For more than 100 years, X-rays have contributed significantly to many sciences and technologies including medicine, astronomy, archaeology and even forensic science.  The exhibition presents a full history of X-rays and their wide variety of applications, as well the future outlook, in a comprehensive manner that is aimed at non-specialists.  Some interesting X-ray images are displayed, such as scans of a 400-year-old picture of so-called hidden Christians (who continued to practice Christianity in secret despite suppression by the government of Japan at that time) and the mummy of a bird (Crested Ibis) from ancient Egypt.  During this special event, 4 lectures will be given.  The museum’s web page is http://www.museum.kyoto-u.ac.jp/index_e.htm

 

Thermo’s new WDXRF spectrometer (May 20, 2010)

Thermo Fisher Scientific Inc., has announced a new addition to its ARL 9900 IntelliPower series of X-ray spectrometers.  For further information, visit the web page, http://www.thermoscientific.com/xray/
 

e2V detector for Japanese satellite en route to Venus (May 20, 2010)

The e2v CCD47-20 was selected as the ultraviolet imager for the Japan Aerospace Exploration Agency’s (JAXA) Venus Climate Orbiter “Akatsuki” (formally known as PLANET-C) to study the planet Venus.  This sensor is a frame transfer CCD, with 1024 × 1024 pixels, each 13μm square. The device is back-illuminated, with optimised processing and coatings for performance in the 280-365nm wavelength range. For further information, visit the web page, http://www.e2v.com/

 

Agilent Technologies acquires Varian (May 14, 2010)

Agilent Technologies Inc. has announced the acquisition of Varian, Inc. for US$1.5 billion.  For further information, visit the web page, http://www.agilent.com/
 

Oxford Instruments receives Queen’s award (April 21, 2010)

Oxford Instruments NanoScience has been awarded The Queen’s Award for Enterprise: Innovation.  For further information, visit the web page, http://www.oxford-instruments.com/

SpectroscopyNow.com

For additional news about X-ray analysis and other spectroscopy sciences, browse the Wiley website.

Kenji Sakurai
Director, X-Ray Physics Group, National Institute for
Materials Science (NIMS)
and Professor, Doctoral Program in Materials Science and
Engineering, Graduate School of Pure and Applied Sciences,
 University of Tsukuba
1-2-1, Sengen, Tsukuba, Ibaraki 305-0047 Japan
Phone : +81-29-859-2821, Fax : +81-29-859-2801
sakurai@yuhgiri.nims.go.jp
http://www.nims.go.jp/xray/lab/