NIMS X-RAY LABORATORY directed by Kenji Sakurai

Since 2004, NASA's Mars Exploration Rovers Opportunity and Spirit have continued to transmit a wealth of exciting images and extremely valuable analytical data on the surface of Mars, including several pieces of evidence pointing to the existence of water in sedimentary rock.  Unfortunately, Spirit recently got stuck in a sand trap, from which it was helpless to extricate itself because two of its six wheels are not working any more.  Scientists hope that, even in its marooned state, Spirit will be able to measure Martian gravity to determine if the planet is solid or liquid at its core.  For further information, visit the Web page, http://www.nasa.gov/rovers

So far, it has been understood that the only way to realize hard-X-ray mirrors with near 100% reflectivity is the use of total external reflection at grazing incidence to a surface.  Dr. Y. V. Shvyd'ko (Argonne National Lab, USA) and his colleagues have recently proposed to use Bragg reflections from synthetic diamond crystal.  They discussed how it shows an unprecedented reflecting power at normal incidence with meV order narrow bandwidths for hard X-rays.  The optics might be a good candidate for X-ray free-electron laser oscillators (X-FELO).  For more information, see the paper, "High-reflectivity high-resolution X-ray crystal optics with diamonds", Y. V. Shvyd'ko et al., Nature Physics, doi:10.1038/nphys1506; published online, 17 January 2010.

A research group led by Professors Y. Takanishi (Kyoto University, Japan) and A. Iida (Photon Factory, KEK, Japan) has recently published its successful investigation into the local layer structure of bent-core liquid crystal, 4-Br-14-O-PIMB, which includes Br atoms.  The group employed a monochromatic X-ray microbeam (3 μm × 4 μm), and observed X-ray scattering from the cell near the Br K absorption edge.  They were able to discover some satellite peaks reflecting the superlattices.  For more information, see the paper, "Microbeam resonant x-ray scattering from bromine-substituted bent-core liquid crystals", Y. Takanishi et al., Phys. Rev. E81, 011701 (2010).

X-ray Photon Correlation Spectroscopy (XPCS) is a novel technique which reveals the slow dynamics of equilibrium and non-equilibrium processes in condensed matter systems.  A group led by Professor N. P. Balsara (University of California, Berkeley, USA) has recently published research on a polystyrene-polyisoprene block copolymer melt in the vicinity of the order-disorder transition.  The group combined several techniques in addition to XPCS; time-resolved small angle X-ray scattering and rheology.  During their studies of ordering kinetics, it was found that two qualitatively different regimes exist, i.e., shallow and deep quench regimes, respectively.  For more information, see the paper, "Dynamic signatures of microphase separation in a block copolymer melt determined by X-ray photon correlation spectroscopy and rheology", A. J. Patel et al., Macromolecules, Article ASAP (DOI: 10.1021/ma902343m).

The UK Science and Technology Facilities Council (STFC) has announced its withdrawal from the European XFEL project.  Due to financial restrictions, the Council had to reprioritise its budget of ca. 2.7 billion Euro over the next five years.  For more information, visit the UK's science programme prioritisation 2010-2015 web page,

http://www.scitech.ac.uk/About/Stats/Rev/intro.aspx

Dr. G. J. Havrilla (Los Alamos National Lab., USA; one of the associate editors of X-Ray Spectrometry journal) and his colleague recently published a very interesting report on the analysis of picoliter droplets, which can be now accurately prepared using Hewlett-Packard's extremely sophisticated technology.  The research targets application to analytical science, although the instrument is basically designed for inkjet printing and other similar purposes.  It has been shown that dried deposits of single and multielemental solutions generated in picoliter volumes are able to be used as references for micro X-ray fluorescence.  Evaporation can have a strong influence on extremely small amounts at the picoliter level, but the research group successfully devised the optimal instrumental conditions by monitoring X-ray fluorescence intensity.   For more information, see the paper, "Picoliter droplet deposition using a prototype picoliter pipette: Control parameters and application in micro X-ray fluorescence", U. E. A. Fittschen et al., Anal. Chem., 82, 297 (2010).

For many years, substantial effort has been devoted to developing a good mirror for preparing a small X-ray beam.  Professor K. Yamauchi (Osaka University, Japan) and his colleagues have recently reported the breaking of the 10 nm barrier for hard X-rays.  They employed a combination of two mirrors; the surface of the first mirror is deformable, in order to compensate for figure error of the second mirror.  By such an adaptive optical system, the research group attained a beam size of 7 nm at 20 keV.  The experiments were done at BL29XUL, SPring-8.  For more information, see the papers, "Breaking the 10 nm barrier in hard-X-ray focusing", H. Mimura et al., Nature Physics doi:10.1038/nphys1457; published online: 22 November 2009; corrected online: 2 December 2009.

Foamlike, cellular structures of the monolayer of organic capped nanoparticles can sometimes be observed on liquid surfaces.  Professor M. K. Sanyal (Saha Institute of Nuclear Physics, India) and his lab members studied the time evolution in the structure and morphology of transferred monolayers of gold-thiol nanoparticles, formed at the air-water interface at different surface pressure, on to a silicon surface.  The research group employed two complementary techniques, X-ray reflectivity and atomic force microscopy (AFM), to see the whole drying-mediated self-assembly of nanoparticles.  For more information, see the paper, "Nanopattern formation in self-assembled monolayers of thiol-capped Au nanocrystals", R. Banerjee et al., Phys. Rev. E80, 056204 (2009).

From right to left: A. Hokura, T. Shiraiwa, S. Ikeda, H. Wakita and H. Hayashi.

So far, X-ray microscopy with many types of lens has achieved great success in the observation of biological cells.  In order to extend the limits of spatial resolution and efficiency, X-ray diffraction microscopy (also called coherent X-ray diffraction imaging), which uses coherent X-rays and some image reconstruction algorithms instead of an optical lens system, is now considered as a promising procedure to see whole cells at once and pick out much smaller features, down to around 10 nm or even less.  A research group led by Professor C. Jacobsen (Stony Brook University, USA) recently reported the results for yeast cells with 520 eV soft X-rays at the Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory, USA.  Dr. A. Madsen (European Synchrotron Radiation Facility (ESRF), Grenoble, France) and his colleagues observed the cells of the bacteria D. radioduran with 8 keV X-rays.  The advantage of using hard X-rays is the ease of sample handling, and the validity of thin sample approximation for future 3D reconstructions through phasing a diffraction volume.  In both cases, a rapid freezing technique (instead of previously used freeze-drying) was used to avoid the effects of radiation damage from synchrotron X-ray photons.  The Stony Brook group plunged cells in their natural wet state into liquid ethane and maintained them at below -170 ^oC, leading to the reduction of artifacts due to damage from dehydration, ice crystallization, and radiation.  In the ESRF setup, as absorption in air of 8 keV X rays is small, a nonvacuum environment was implemented for ease of sample handling.  Similar to the system for macromolecular crystallography applications, they based the samples in a continuous cryogenic nitrogen gas jet at around -165 ^oC.  The spatial resolution was 25 nm and 30-50 nm, for soft and hard X-rays cases, respectively.  For more information, see the papers, "Soft X-ray diffraction microscopy of a frozen hydrated yeast cell", X. Huang et al., Phys. Rev. Lett., 103, 198101 (2009), and "Cryogenic X-ray diffraction microscopy for biological samples", E. Lima et al., Phys. Rev. Lett., 103, 198102 (2009)

The discovery of X-rays was named the most important modern scientific achievement in a poll conducted for the Science Museum London, beating the Apollo spacecraft and DNA.  Nearly 50,000 members of the public voted in the museum or online.  The emblem of the London museum's centenary is now an X-ray machine.  For further information, visit the museum's Web page, http://www.sciencemuseum.org.uk/

X-ray absorption microscopy is simple, but has low sensitivity in biological samples that are made of light elements.  X-ray phase contrast imaging can provide contrast that is 3 orders of magnitude greater than X-ray absorption.  However, phase contrast imaging has not been that widely used so far mainly because of the unusual requirements of the experimental setup.  Dr. W. Yashiro (The University of Tokyo, Japan) and his colleagues have recently proposed a novel setup that is feasible.  The research group simply added a transmission grating to the setup for conventional X-ray absorption microscopy with a Fresnel Zone Plate (FZP) objective lens.  Because of the self-imaging phenomenon in Talbot effects, a phase difference image can be produced by the transmission grating placed at the downstream of the back focus of the FZP.  The experiment was done at beamline BL20XU, SPring-8.  For more information, see the paper, "Hard-X-Ray Phase-Difference Microscopy Using a Fresnel Zone Plate and a Transmission Grating", W. Yashiro et al., Phys. Rev. Lett. 103, 180801 (2009).

A recent edition of Nature News featured the international race to build X-ray free electron laser facilities. At the Linac Coherent Light Source (LCLS), Stanford, USA, scientists have succeeded in lasing 8 keV X-rays and started to use them in their research since April, this year (2009).  Meanwhile, soft X-ray laser FLASH, which is a pilot facility for XFEL at the European X-Ray Free-Electron Laser (XFEL), Hamburg, Germany, has been open for scientific use since 2005, and the main XFEL will be completed in 2014.  Nature News interviewed various people both in Stanford (Joachim Stohr, Jerome Hastings and John Bozek) and Hamburg (Heinz Graafsma, Helmut Dosch and Massimo Altarelli).  For more information, see the article, "X-ray free-electron lasers fire up", Eric Hand, Nature 461, 708-709 (2009).

At Stanford's linac coherent light source (LCLS), a great deal of effort has been devoted since April this year to initial scientific tests of an X-ray laser.  In September, scientists attempted to strip all ten electrons from an atom of neon.  They were able to adjust the proportion of different neon species, from non-ionized Ne (no missing electrons) to Ne¹⁰⁺ (lacking all 10 electrons), by fine-tuning the powerful LCLS X-ray beam.  For more information, visit the Web page, http://today.slac.stanford.edu/

It is known that sulfide sometimes play a significant role in the geochemistry of arsenic under reducing conditions.  So far, it has been assumed that sulfide primarily reduced the solubility and mobility of arsenic by precipitation of arsenic-sulfide minerals, As₂S₃, but recent studies indicate that under certain conditions, significant concentrations of soluble As-S compounds can exist in sulfidic waters.  Thus, the question is whether they are As(III)-S species ("thioarsenites") or As(V)-S species ("thioarsenates").  A research group led by Dr. B. Planer-Friedrich (University of Bayreuth, Germany) has recently reported that use of X-ray absorption spectroscopy (XANES and EXAFS) can determine the concentration ratio of each species.  The experiment was done at beamline BM20, ESRF.  For more information, see the paper, "Discrimination of Thioarsenites and Thioarsenates by X-ray Absorption Spectroscopy", E. Suess et al., Anal. Chem., Article ASAP (2009), DOI: 10.1021/ac901094b

Dr. C. T. Chanter and his colleagues have published a paper on the unresolved quantitative discrepancies between experimental and theoretical Cu Kα spectra.  For more information, see the paper, "Theoretical Determination of Characteristic X-Ray Lines and the Copper Kα Spectrum", C. T. Chantler et al., Phys. Rev. Lett. 103, 123002 (2009).

Nearly $19 million in funding through the American Recovery and Reinvestment Act is supporting the Cornell High Energy Synchrotron Source (CHESS), Cornell Electron Storage Ring (CESR) and ongoing efforts to plan and build a new linear accelerator, the Energy Recovery Linac (ERL).  So far, Cornell has received more than 90 ARRA grants, totally about $76 million.  For more information, visit the Web page, http://www.news.cornell.edu/

Japan is celebrating the 1,300th anniversary of Kohfukuji Temple in Nara.  The temple's sculpture of Ashura, one of the greatest treasures of the early to mid-7th century, is on exhibition at Kyushu National Museum in September. The exhibition features some X-ray imaging results of non-destructive observation of the interior of the sculpture. The images establish that the sculpture is still in good condition and also give a lot of information on the materials and methods used in its creation.  Information on Ashura is available at the following Web page, http://en.wikipedia.org/wiki/Asura_(Buddhism)

So far, diffusion in solids has been investigated by profiling the depth dependence of tracer atoms diffused into the sample.  Although one can obtain the diffusion constant from this, the question is how diffusion takes place on the atomic scale, rather than on the micron scale.  Sometimes quasielastic neutron scattering as well as Mobauer spectroscopy can be used in a very limited number of fortunate cases.  A research group led by Professor G. Vogl (University of Vienna, Austria) recently reported the use of X-ray photon correlation spectroscopy (XPCS) to observe the dynamics of diffusing atoms.  The research was done for intermetallic alloy Cu₉₀Au₁₀, at temperatures of around 540 K, where the system is a substitutional solid solution, that is, the Au atoms statistically occupy sites in the Cu fcc lattice.  The research gives the dynamical behavior of single atoms as a function of their neighborhood, and confirms quantitatively that Au atoms have a tendency to locally order on a certain set of sites in the crystal.  Photon correlation spectroscopy is based on analysis of 'speckle' patterns, which are fine-scale diffraction patterns that appear in the scattering of coherent light from a disordered system.  Speckle patterns are sensitive to the exact spatial arrangement of the disorder.  By observing the intensity fluctuations in the speckle pattern, the characteristic times of fluctuations in the system can be determined.  For more information, see the paper, "Atomic diffusion studied with coherent X-rays", M. Leitner et al., Nature Materials,8, 717 (2009).

Chandrayaan-1 was a lunar probe launched by the Indian Space Research Organization (ISRO).  It was equipped with advanced X-ray spectrometers for investigation.  After suffering from several technical problems including failure of the star sensors and insufficient thermal shielding, Chandrayaan stopped sending radio signals on August 29, 2009 shortly after which the ISRO officially declared the mission over.  Chandrayaan operated for 312 days from October 2008.  For more information, visit the Web page,http://www.isro.org/Chandrayaan/htmls/home.htm

When a strong laser beam hits the surface of a material, plasma is produced there, subsequently leading to the emission of a short burst of X-rays.  It is believed that the electrons in the surface plasma are accelerated by the strong electric field of the laser and then penetrate the solid behind. There, they knock out electrons from inner electronic shells, which subsequently undergo inner-shell recombination, leading to characteristic line emissions such as Kα and Kβ spectra.  A research group led by Professor U. Teubner (University of Applied Sciences, Emden, Germany) has reported detailed experimental results on copper and titanium K X-rays.  Particular attention has  been paid to the interplay between the angle of incidence of the laser beam on the target, as well as the influence of prepulses.  For more information, see the paper, "Optimized K x-ray flashes from femtosecond-laser-irradiated foils", W. Lu et al., Phys. Rev. E 80, 026404 (2009).

In X-ray diffraction experiments, one measures the intensity (amplitude) of the diffracted X-rays as a function of position in the reciprocal space, and the information on the phase is always missing.  For many years, this so-called phase problem has been thought as one of the biggest problems in X-ray crystallography.  Professor E. Wolf (University of Rochester, New York) has recently published a very interesting and inspirational paper.  He is famous for several important textbooks on optics and also for his presidency of the Optical Society of America.  The present paper is theoretical, and starts with a criticism of basic understanding of the problem. The author says that trying to measure the phase is rather meaningless.  Almost all scientists assume that the incident X-ray beam is monochromatic in the data analysis, but the author points out that a monochromatic beam is not possible in reality.  Any beam that can be produced in a laboratory is, at best, quasimonochromatic and, therefore, even if both the amplitudes and the phases are given, it is still not possible to solve the problem.  Alternatively, the author proposes the measurement of certain correlation functions, with the use of spatially coherent beams.  While it is extremely important to think about a future strategy regarding the final solution of the phase problem as discussed in the paper, the author makes no mention of the recent significant strides in coherent X-ray scattering.  For more information, see the paper, "Solution of the Phase Problem in the Theory of Structure Determination of Crystals from X-Ray Diffraction Experimentst", E. Wolf, Phys. Rev. Lett. 103, 075501 (2009).

X-ray phase-contrast imaging is extremely powerful for visualizing internal structures with low-Z matrices, which are most likely in bio-medical specimens.  The use of an X-ray interferometer is one of the most promising ways forward for this imaging technology, but resolution has been limited to the micrometer scale so far.  A research group led by Dr. A. Snigirev (European Synchrotron Radiation Facility, Grenoble, France) has recently developed a novel type of X-ray interferometer employing a bilens system with two parallel arrays of compound refractive lenses, each of which creates a diffraction limited beam under coherent illumination.  The energy of the X-rays is 10-20 keV and the material used in the refractive lenses is silicon.  When the two beams overlap, they produce an interference pattern with fringe spacing ranging from tens of nanometers to tens of micrometers.  Readers may notice that the system is similar to the model of a Billet split lens in classical optics (See Fig.7.8, page 263 in "Principle of Optics", M. Born and E. Wolf, 6^th Ed, Pergamon Press (1988)).  The use of a modern synchrotron source and this novel optical device thus opens up a new field and could revive old theorems.  Coherent moiré imaging or radiography are promising straightforward applications.  For more information, see the paper, "X-Ray Nanointerferometer Based on Si Refractive Bilenses", A. Snigirev et al., Phys. Rev. Lett., 103, 064801 (2009).

The following awards were presented during the plenary session of the 58th Annual Denver X-Ray Conference:

The 2009 Barrett Award was presented to Robert Von Dreele, Argonne National Laboratory, Argonne, IL.

The 2009 Jenkins Award was presented to Tim Fawcett, International Centre for Diffraction Data, Newtown Square, PA.

There was no winner for the 2009 Jerome B. Cohen Student Award.

A recent edition of Nature News featured the successful application of a carbon nanotube (CNT)-based X-ray source to medical imaging.  A group led by Professor O. Zhou (University of North Carolina in Chapel Hill, USA) has developed a micro 3D CT system.  The main idea behind such very rapid scanning is simply electronic switching of 3D arrayed CNT X-ray sources, rather than mechanical motion.  For more information, see the article, "Nanotubes sharpen X-ray vision", Zeeya Merali, Nature News, doi:10.1038/news.2009.744  The original research papers were published in April 2009 ("A dynamic micro-CT scanner based on a carbon nanotube field emission X-ray source", G Cao et al Phys. Med. Biol. 54, 2323 (2009))

It is well known that the physical properties of semiconductor nanostructures, which have been grown in most cases by the Stranski-Krastanow (SK) mechanism, depend on their size, shape, strain and composition.  In the case of the growth of Ge on Si(001), where the 2D-3D transition is driven by the 4.16% lattice mismatch between Ge and Si, the increase of Ge coverage above a critical thickness of around 4 ML can make coherent islands.  First, square pyramids appear, and then dome-shaped islands are formed.  At about 9 ML, the misfit strain can no longer be accommodated coherently and larger islands called superdomes are present. This raises detailed questions as to dependence on the growth rate, temperature etc.  To provide answers to such questions, in-situ X-ray studies are extremely important.  Professor G. Bauer (Institute of Semiconductor and Solid State Physics, Johannes Kepler University in Linz, Austria) and his colleagues recently performed grazing-incidence small angle X-ray scattering (GISAXS) and diffraction (GID) experiments with a UHV-MBE chamber.  They clarified the kinetics of the growth of Ge superdomes and their facets on Si(001) surfaces, as a function of deposited Ge thickness for different growth temperatures at a low growth rate, by in situ grazing-incidence small-angle x-ray scattering in combination with in situ grazing-incidence x-ray diffraction. At a low growth rate, intermixing is found to be enhanced and superdomes are formed already at lower coverages than previously reported. In addition, the research team observed that at the dome-to-superdome transition, a large amount of material is transferred into dislocated islands, either by dome coalescence or by anomalous coarsening. Once dislocated islands are formed, island coalescence is a rare event and introduction of dislocations is preferred. The superdome growth is thus stabilized by the insertion of dislocations during growth.  For more information, see the paper,   "In situ X-ray scattering study on the evolution of Ge island morphology and relaxation for low growth rate: Advanced transition to superdomes", M.-I. Richard et al., Phys. Rev. B 80, 045313 (2009).

Since 1984, laboratory-scale X-ray lasers have been extensively studied.  The shortest wavelength achieved so far is 3.6 nm, with a weak intensity.  On the other hand, X-ray free-electron lasers (XFEL) based on self-amplified spontaneous emission (SASE) from a long undulator in the linear electron accelerator will be available in near future.  The next idea is the use of XFEL to pump a photoionization inner-shell X-ray laser in an atomic gas.  Dr. R. London (Lawrence Livermore National Lab) and a colleague have recently published their theoretical calculations.  For more information, see the paper, "Atomic inner-shell X-ray laser pumped by an x-ray free-electron laser", N. Rohringer et al., Phys. Rev. A 80, 013809 (2009).

The 2009 workshop on 'buried' interface science with X-rays and neutrons was held at Akihabara campus, Tsukuba University, Japan, on July 13-14, 2009.  The workshop was the latest in a series held since 2001; Tsukuba (December 2001), Niigata (September 2002), Nagoya (July 2003), Tsukuba (July 2004), Saitama (March 2005), Yokohama (July 2006), Kusatsu (August 2006), Tokyo (December 2006), Sendai (July 2007), Sapporo (September 2007), Tokyo (December 2007) and Tsukuba (March 2009).  There are increasing demands for sophisticated metrology in order to observe multilayered materials with nano-structures (dots, wires, etc), which are finding applications in electronic, magnetic, optical and other devices.  X-ray and neutron analysis is known for its ability to observe in a non-destructive manner even 'buried' function interfaces as well as the surface.  In addition to such inherent advantages, recent remarkable advances in micro analysis and quick time-resolved analysis in X-ray reflectometry are extremely important.  The present workshop gathered together those with different research backgrounds, i.e., from semiconductor electronics to chemical bio materials, and even theoretical groups were invited to give insights into unsolved problems on buried interfaces.  The workshop proceedings will be published in Transactions of the Materials Research Society of Japan, no later than the end of 2009.   

Kyushu University has recently constructed its own new beamline at the SAGA Light Source, which is one of Japan's compact synchrotron facilities. For more information, visit the Web page, http://www.saga-ls.jp/

Imaging individual objects of several nanometer resolution in space and several femtosecond resolution in time, is now one of the most exciting experiments in X-ray physics.  Over the past decade, coherent X-ray diffraction has overcome a lot of limits in imaging noncrystalline objects at a resolution in the order of X-ray wavelength.  So far, X-ray free electron lasers (or, in the mean time, 3^rd generation synchrotron sources) have been considered as a promising source, but the table-top source is no doubt extremely important for many new sciences.  Recently, Dr. H. Merdji (CEA Saclay, France) and his colleagues reported the feasibility of a laser-driven soft X-ray source, which uses the 25^th harmonics (32 nm wavelength, 20 fs pulse width) of a Ti:sapphire laser.  They succeeded in observing diffraction patterns from isolated nano-objects with a single 20 fs pulse.  Images were reconstructed with a spatial resolution of 119 nm from the single shot and 62 nm from multiple shots.  For more information, see the paper, "Single-Shot Diffractive Imaging with a Table-Top Femtosecond Soft X-Ray Laser-Harmonics Source", A. Ravasio et al., Phys. Rev. Lett. 103, 028104 (2009).

Dr. P. Glatzel (European Synchrotron Radiation Facility (ESRF), Grenoble, France) and his colleagues recently published an interesting paper reporting systematic studies on both X-ray absorption and Kα emission spectra from sulfur compounds.  The compounds' spectra were compared with quantum chemical calculations using density functional, multiple-scattering, and atomic multiplet theory.  It was found that the near-edge absorption spectra are mainly determined by the geometry of the first coordination sphere in the case of the sulfates and sulfite, while strong orbital hybridization in the case of sulfides results in a much more complex analysis.  On the other hand, the spectral shape of the Kα fluorescence lines shows little influence of the chemical environment, but its energy position is correlated with the valence-shell electron population.  The experiments were done at beamline ID26, ESRF.  The spectrometer used for Kα emission is a combination of a Johansson Si(111) crystal and a CCD camera.  The energy resolution was 0.44 eV for S Kα.  For more information, see the paper, "Electronic Structure of Sulfur Studied by X-ray Absorption and Emission Spectroscopy", R. A. Mori et al., Anal. Chem., Article ASAP, DOI: 10.1021/ac900970z

In January 2006, NASA's Stardust spacecraft brought comet coma particles and interstellar grains from Comet 81P/Wild2.  Synchrotron facilities all over the world have been used for extensive analysis of the chemical composition and crystal structures of the matter.  Recently, Professor L. Vincze (X-ray Microspectroscopy and Imaging Group, Ghent University, Belgium) and his colleagues reported the results of 3D X-ray imaging based on X-ray fluorescence (XRF) tomography.  In the present research, a 200 nm beam was employed, because the typical size of the particles from space was 2 microns.  The measurement consisted of 2D scanning XRF maps for each rotation angle of the sample.  In the XRF spectra, many peaks were found; Ca, Cr, Mn, Fe, Cu, Se etc. For more information, see the paper, "X-ray Fluorescence Nanotomography on Cometary Matter from Comet 81P/Wild2 Returned by Stardust", G. Silversmit et al., Anal. Chem., Article ASAP, DOI: 10.1021/ac900507x  For related work on the same 'star dust' by other groups, for example, see "Chondrulelike Objects in Short-Period Comet 81P/Wild 2", Tomoki Nakamura et al., Science, 321, 1664-1667 (2008) and "Mixing Fraction of Inner Solar System Material in Comet 81P/Wild2", A. J. Westphal et al, The Astrophysical Journal, 694, 18-28 (2009).

As reported here previously, in April this year, the first 1.5 Å wavelength laser light was generated at Stanford, USA.  An interesting account of the hard X-ray laser was published in Nature Photonics.  See the article, "Free electron lasers: First light from hard X-ray laser", B. McNeil, Nature Photonics, 3, 375-377 (2009).

Confocal X-ray micro fluorescence is a method of 3D analysis, and uses the formation of confocal volume (probing microvolume) defined through the intersection of a focused excitation beam and the sensitive volume of a polycapillary lens placed in front of the detector.  Because of increasing demands, the technique has been widely used at both synchrotron and laboratory sources.  However, some essential problems in quantitative analysis have remained so far.  Dr. A-G. Karydas (Institute of Nuclear Physics, N.C.S.R. "Demokritos", Greece) and his colleagues recently published a paper on the influence of the secondary fluorescence enhancement in this technique.  For more information, see the paper, "Secondary Fluorescence Enhancement in Confocal X-ray Microscopy Analysis", D. Sokaras et al., Anal. Chem., Article ASAP, DOI: 10.1021/ac900688n

Demand for learning analytical techniques for surfaces and interfaces appears to be on the increase.  At Tsukuba in Japan, the 3rd tutorial course on the analysis of thin films and multilayers by X-ray reflectivity was held on May 22.  The first Japanese textbook that serves as an introduction to X-ray reflectivity was published in February, and the 7 authors gave lectures as part of the course.  Further information is available at http://www.nims.go.jp/xray/ref/ (in Japanese only).

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

From right to left: Mr. Matthias Muller (PTB, Ph.D. student, X-ray Spectrometry group), Prof. Mathias Richter (PTB, Head of Department, X-ray Metrology using Synchrotron Radiation), Dr. Burkhard Beckhoff (PTB, Head of X-Ray Spectrometry group), Dr. Kenji Sakurai (NIMS, Group Leader, Quantum Beam Center).

The Chemical Heritage Foundation (CHF) has announced that Dr. Alfred Bader (Cofounder of Aldrich Chemical Company, former chairman of Sigma-Aldrich Corporation) has received the 2009 annual Pittcon Heritage Award.  Jointly sponsored by the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy (Pittcon) and CHF, this award recognizes outstanding individuals whose entrepreneurial careers have shaped the instrumentation community, inspired achievement, promoted public understanding of the modern instrumentation sciences, and highlighted the role of analytical chemistry in world economies.  Dr. Bader founded the Aldrich Chemical Company, a fine chemicals company that later would become the Sigma-Aldrich Corporation, the 80^th largest chemical company in the United States.  In 1995, he published his autobiography, "Adventures of a Chemist Collector", which details his experiences from Nazi-era refugee to chemist magnate to fine arts connoisseur.  In 2008, the second autobiography has been published, "Chemistry & Art: Further Adventures of a Chemist Collector".

The use of short pulses of extremely bright synchrotron X-rays has opened up a new world.  In Japan, Dr. S. Adachi (KEK, Tsukuba Japan) and his colleagues recently succeeded in recording movies during changes in the molecule structures of myoglobin.  The samples used are frozen myoglobin crystals that had CO (carbon monoxide) stored inside before the start of the experiments.  Even at 100K, irradiating pulsed laser light gave the trigger for the migration of CO molecules.  To see changes in atomic scale, time-resolved X-ray diffraction measurements were performed.  The obtained movie tells us that the CO molecules penetrate into a number of cavities in the crystal and even expand their size.  The research group has obtained an important result suggesting some self-opening mechanism in the ligand migration channel.  For more information, see the paper, "Visualizing breathing motion of internal cavities in concert with ligand migration in myoglobin", A. Tomita et al., Proceedings of National Academy of Science, 106, 2612-2616 (2009) Published online before print February 9, 2009, doi: 10.1073/pnas.0807774106

An international symposium on micro and trace X-ray analysis was held in Osaka, Japan, on February 12-14, with financial aid from the Japan Science and Technology Agency (JST).  Professor K. Tsuji (Osaka City Univ.) organized the symposium, which had 102 participants including 12 scientists from outside Japan.  In addition to highly sophisticated analytical experiments with brilliant synchrotron radiation, recent progress regarding the instrumentation and applications of laboratory/mobile X-ray sources was extensively discussed.  The speakers were as follows; P. Wobrauschek (Atominstitut, TU Wien), K. Janssens (Antwerp Univ.), A. Hokura (Tokyo Univ. of Sci.), K. Nakano (Osaka City Univ.), A. von Bohlen (ISAS Institute for Anal. Sci.), S. Maeo (Osaka Electro-Comm. Univ.), Y. Kataoka (Rigaku), G. Havrilla (Los Alamos National Lab), C. Numako (Tokushima Univ.), K. Hayashi (Tohoku Univ.), T. Sakae (Nihon Univ.), K. Sakurai (National Inst. for Materials Sci.), S. Hayakawa (Hiroshima Univ.), K. Tsuji (Osaka City Univ.), S. B. Dabagov (INFN, Frascati), N. Gao (X-Ray Optical Systems, Inc.), H. Soejima (Shimadzu), K. Taniguchi (Inst. of X-ray Tech. Co., Ltd), J. E. Fernandez (Bologna Univ.),  H. Kumagai (Osaka City Univ.), A. Bando (Horiba Ltd.), K. Yamauchi (Osaka Univ.), B. De Samber (Ghent Univ.), Y. Kagoshima (Hyogo Univ.), C. Streli (Atominstitut, TU Wien), P. Pianetta (SLAC, Stanford), S. Shimoyama (Kibi International Univ.), R. Van Grieken (Antwerp Univ.).  The proceedings booklet is available from the organizer, Phone/Fax: +81-6-6605-3080, tsuji@a-chem.eng.osaka-cu.ac.jp

In classical metallurgy, there exists a very famous rule known as Hume-Rothery's rule, which describes the conditions necessary for the formation of a solid solution from two independent metals.  In order to have a substitutional crystalline solid solution in which the atoms of one element randomly substitute for atoms of another element in a crystal structure, the components must have an atomic size within 15% and electronegativity within 0.4 of each other.  According to this rule, a Ce-Al solid solution cannot be obtained.  Recently, a research team led by Professor H.K. Mao (Carnegie Institution of Washington) and Professor R. Ahuja (Uppsala University) found during high pressure research on the intermetallic compound of Ce₃Al that a solid solution is formed in a Ce-Al system.  The differences in radii and electronegativity of Ce and Al were diminished by applying pressure.  Both synchrotron X-ray studies (XRD and X-ray absorption spectroscopy) and ab initio calculations showed the same cause for bringing the two elements closer in radii and electronegativity, resulting in the new alloy phase.  Even after the release of pressure, this substitutional alloy remained.  During in-situ X-ray absorption measurements at the Ce LIII edge, conspicuous changes in the sharpness of the absorption, correlated to delocalization of 4f electrons, were observed.  For more information, see the paper, "Substitutional alloy of Ce and Al", Q-S.Zeng et al., Proceedings of National Academy of Science, 106, 2515-2518 (2009) Published online before print February 2, 2009, doi: 10.1073/pnas.0813328106

Eu is one of the most interesting lanthanides, compounds of which often exhibit remarkable optical, electrical, and magnetic properties.  Therefore, it is extremely important to develop a technique for chemical state analysis.  The X-ray emission spectra of Eu had not been thought to exhibit significant chemical effects.  A research group led by Professor H. Hayashi (Japan Women's Univ) firstly found a large chemical shift (~5 eV) in Eu Lγ₄ emission line, depending on the valence state.  They discussed the feasibility of using this as a probe for spin- and valence-selective X-ray absorption fine structure spectroscopy.  For more information, see the paper, "Probe for spin- and valence-selective X-ray absorption fine structure spectroscopy: EuLγ₄ emission", H. Hayashi et al., Anal. Chem., 81, 1522 (2009).

X-ray absorption spectroscopy is one of the most powerful probes of molecular structures.  So far, applications have been limited to the steady state and/or quite slowly changing systems.  Recently, Professor M. Chergui (Ecole Polytechnique Federale de Lausanne, (EPFL), Switzerland) and his colleagues reported a very impressive ultrafast X-ray absorption experiment.  There is a large class of Fe(II)-based molecular complexes that show two electronic states closely spaced in energy: a low-spin (LS) singlet and a high-spin (HS) quintet state. They therefore exhibit spin crossover (SCO) behavior, wherein conversion from a LS ground state to a HS excited state (or the reverse) can be induced by small changes in temperature and pressure or by light absorption.  The studies were done for an aqueous solution of [Fe^II(bpy)₃]²⁺, which serves as a model system for the family of Fe(II)-based SCO complexes.  A 100-mm-thick free-flowing liquid jet of an aqueous solution of 50 mM [Fe^II(bpy)₃]²⁺ was excited by an intense 400-nm laser pulse (115-fs pulse width, repetition rate 1 kHz), and a tunable femtosecond hard X-ray pulse from the slicing source was used to probe the system in transmission mode at 2 kHz.  The X-ray flux was about 10 photons/pulse at 7 keV.  The time resolution was under 250 fs.  By recording the intensity of a characteristic near edge absorption spectral feature as a function of laser pump/X-ray probe time delay, the very early stages of photo excitation in Fe(II)-based complexes were clarified.  For more information, see the paper, "Femtosecond XANES Study of the Light-Induced Spin Crossover Dynamics in an Iron(II) Complex", Ch. Bressler et al., Science, 323, 489 (2009).

The Science and Technology Foundation of Japan has announced that two US scientists have been named as laureates of the 2009 (25th) Japan Prize.  Dr. Dennis L. Meadows, 66, Professor Emeritus of Systems Policy, University of New Hampshire and one of the authors of the report, "The Limits to Growth," for the Club of Rome in 1972, has received the prize in this year's category of "Transformation towards a sustainable society in harmony with nature".  Dr. David E. Kuhl, 79, Professor of Radiology, University of Michigan Medical School, was selected in the other prize category of "Technological integration of medical science and engineering".  They will receive certificates of merit, and commemorative medals.  There is also a cash award of fifty million Japanese yen for each prize category.  The presentation ceremony is scheduled to be held in Tokyo at the National Theatre on Wednesday 23rd April, 2009.  The prize categories for the 2010 (26th) Japan Prize will be "Industrial Production and Production Technology" and "Biological Production and Environment".  For further information, visit the Web page, http://www.japanprize.jp/en/index.html

The U.S. Department of Energy (DOE) has granted "Critical Decision 3" (CD-3) status to the National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory, approving the start of construction in fiscal year (FY) 2009 and scheduling completion in FY 2015.  A total project cost for NSLS-II of $912 million has been approved.  NSLS-II is expected to be the world's first storage-ring-based synchrotron light source that combines nanometer spatial resolution with high brightness, coherence, and beam stability, enabling nanometer-scale characterization of materials, with powerful applications in nanotechnology and biotechnology.  For more information about the NSLS-II project, visit the website at http://www.bnl.gov/nsls2/

Laser generation in the X-ray region has become realistic because of the construction of free electron laser facilities, which will be available in the near future (Linac Coherent Light Source (LCLS) at Stanford in 2009; European XFEL in 2014).  Another significant route is the extension of existing laser technologies such as high-order harmonic generation (HOHG), particularly from relativistically oscillating plasma mirror-like surfaces.  Professor M. Zepf (Queens University Belfast, UK) and his colleagues recently published an interesting paper showing that it is possible to achieve a near-diffraction-limited focal spot size that is also controllable.  For more information, see the paper, "Diffraction-limited performance and focusing of high harmonics from relativistic plasmas", B. Drome et al., Nature Physics, advanced online publication doi:10.1038/nphys1158

Professor T. Rayment (School of Chemistry, University of Birmingham, UK) and his colleagues have developed a channel-flow cell to study electrochemical reactions on electrodes by time-resolved X-ray absorption spectroscopy.  During the studies with the model system, it was found that a flowing solution is essential to remove any products of beam damage.  For more information, see the paper, "Channel-Flow Cell for X-ray Absorption Spectroelectrochemistry", R. J. K. Wiltshire et al., J. Phys. Chem., C 113, 308 (2009)

Lyncean Technologies, Inc., which was founded in Palo Alto, California, in 2001 by Stanford Professor Ronald Ruth's group, recently announced that its Compact Light Source (CLS) successfully performed hard X-ray phase contrast imaging.  Some results appear on the cover of the January 2009 issue of the Journal of Synchrotron Radiation.  The CLS is a miniature synchrotron which uses inverse Compton scattering to produce high-intensity, tunable, quasi-monochromatic X-ray beams.  For more information, visit the Web page, http://www.lynceantech.com  Their first scientific results are published in the paper, "Hard X-ray phase-contrast imaging with the Compact Light Source based on inverse Compton X-rays", M. Bech et al., J. Synchrotron Rad. 16, 43 (2009).

Toshihisa Horiuchi, the co-author of the first total-reflection X-ray fluorescence (TXRF) paper, has died from colorectal cancer at the age of 66 at a hospital in Fukuoka, Japan, where his son is a doctor.  Horiuchi was a student at Kurume National College of Technology. Immediately after finishing school, he started work as a technical staffer at Professor Y. Yoneda's lab, Kyushu University. He became convinced that the use of a new detector would be crucial for opening up new opportunities in X-ray spectroscopy, and he eagerly proposed that his supervisor purchase Si(Li) and Ge detectors, although they were too expensive for the university lab at that time.  One of the most important applications for the then new detectors was TXRF. The paper, "Optical Flats for Use in X-Ray Spectrochemical Microanalysis", Rev. Sci. Instrum. 42, 1069 (1971) is a very famous work. This reported the first successful results of TXRF. Horiuchi was aware of the significance of trace analysis of bio-medical specimens such as blood etc, and he wanted to employ TXRF for such applications. After the death of Professor Yoneda, he moved to another lab and worked in the field of organic thin films for electronic devices.  He contributed substantially to both research and teaching students.  On February 14, 2009 at Osaka City University, Japan, Professor K. Matsushige (Kyoto University), who had supervised Horiuchi for more than 18 years, gave a memorial speech, taking advantage of the opportunity of the international symposium on micro and trace X-ray analysis.  The participants offered a silent prayer for Horiuchi.

Diffractive imaging is a technique for so-called lens-less microscopy, and uses diffraction intensity (image) and phase retrieval calculations rather than focusing systems such as lenses, which are not free from aberrations.  The spatial resolution is basically limited only by the amount of high-angle scattering.  Therefore, the technique has been considered as having the potential to achieve atomic resolution for hard X-rays or other short-wavelength particle beams.  However, so far, the reported results have been still at the level of several nanometers.  Recently, a research group at the University of Illinois, USA proposed a method of improving the resolution.  One of the biggest technical reasons limiting the spatial resolution of diffractive imaging is the difficulty of recording weak coherent scattering signals.  The research group proposes the combined use of low-resolution imaging, which provides the starting phase, real-space constraint, missing information in the central beam and essential marks for aligning the diffraction pattern.  The group used an electron microscope to see a single CdS quantum dot with sub-angstrom resolution and noted that it is possible to use the same procedure in the case of coherent X-ray scattering.  For more information, see the paper, "Sub-angstrom-resolution diffractive imaging of single nanocrystals", W. J. Huang et al., Nature Physics, advanced online publication doi:10.1038/nphys1161

Eugene P. Bertin, author of the most famous XRF textbooks and a very popular instructor in XRF courses, has died at the age of 86, in his apartment in Harrison, NJ, USA.  Dr. Bertin was a student at the University of Illinois, in Urbana and received his B.S., M.S., and finally PhD in 1952, in Analytical/Inorganic Chemistry.  He worked at the RCA Research Center in Princeton, NJ for many years.  Dr. Bertin made many contributions to X-ray spectroscopy.  He was the principle lecturer at the "Short summer course in X-ray spectrometry" (organized by Professor Henry Chessin, State University of New York at Albany), and also at ICDD XRF courses.  His textbooks, "Principles and Practice of X-Ray Spectrometric Analysis" (Plenum, 1970 (first edition), 1975 (second edition)) and "Introduction to X-Ray Spectrometric Analysis" (Kluwer Academic Pub, 1978) were recognized as the best in the world and were hallmark texts used by thousands of people all over the world.  Reviews of these books have been published in X-Ray Spectrometry journal (See, 1, 45 (1972), 4, A18 (1975), 8, v (1979)).  Another interesting review is found in J. Appl. Cryst., 5, 387 (1972).  Dr. Bertin was a recipient of the Birks Award at the 1988 Denver Conference.  One of his best friends, Dr. V. E. Buhrke has posted an article, "Testimonial and Obituary - in honor of Dr. Eugene P. Bertin, PhD" to the XRF-L mailing list, which can be also read at (http://listserv.syr.edu/scripts/wa.exe?A2=ind0812&L=xrf-l&T=0&F=&S=&P=1003).

Professor L. Natarajan (University of Mumbai, India) recently published a paper calculating the energies and electric dipole rates of X-rays from the empty K shells of atoms in the range of Z=12 to 56.  For more information, see the paper, "Relativistic fluorescence yields for hollow atoms in the range 12<Z<56", L. Natarajan, Phys. Rev. A78, 052505 (2008).

Our lab signed a Memorandum of Understanding (MOU) for research collaboration on the "nanotechnology-driven advanced materials metrology research, X-ray physics and its industrial metrology applications, nanoscale materials characterizations" with Center for Measurement Standards (CMS), Industrial Technology Research Institute (ITRI), Taiwan. The two institutions agreed to promote exchanges of researchers, information, publication of the results of the research and/or the implementation of cooperative research. Both sides are interested in developing and establishing novel advanced metrology as well as the international standardization in Asia-Pacific region.

The significance of the collaboration between NIMS and ITRI was first discussed during the 2007 APEC Nanoscale Measurement Technology Forum, held in Taipei, September, 2007. Dr. Kenji Sakurai (NIMS, Group Leader, Quantum Beam Center) gave an invited lecture on X-ray metrology for nanotechnologies there.