NIMS X-RAY LABORATORY directed by Kenji Sakurai

Mars Rover Spirit loses battle to escape from sand trap

2010-01-25T17:39:20Z

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

MD simulation aids the analysis of local dynamics by EXAFS

2010-01-21T17:39:00Z

Extended X-ray absorption fine-structure (EXAFS) is a powerful tool for the analysis of atomic-scale structure around specific atoms. In addition to the determination of the atomic distance for the nearest neighboring atoms, it can give some information on the local dynamical properties of crystals. Recently, Dr. A. Sanson (Universita degli Studi di Verona, Italy) has published the results of the molecular dynamics (MD) simulation in the case of crystalline germanium. By comparing experimental EXAFS data, he could discuss the radial distribution functions of the first six coordination shells, as well as their parallel and perpendicular mean-square relative displacements as a function of temperature. For more information, see the paper, "Local dynamical properties of crystalline germanium and their effects in extended x-ray absorption fine structure", A. Sanson, Phys. Rev. B81, 012304 (2010).

Micro XRF analysis of industrial waste

2010-01-20T17:39:34Z

Professor M. A. Castro (Instituto de Ciencia de los Materiales de Sevilla, CSIC-Universidad de Sevilla, Spain) and his colleagues are proposing to employ micro X-ray fluorescence as a feasible and efficient solution to classify waste and also to survey the problems in the production process. For more information, see the paper, "Application of micro-X-ray fluorescence analysis for the characterization of industrial wastes", M. D. Alba et al., Ind. Eng. Chem. Res., Article ASAP (DOI: 10.1021/ie901716w).

Kβ satellites in EPMA

2010-01-18T17:39:57Z

Argentinian scientists have recently published a paper on the emission of X-rays in the Kβ region of Mg, Al, Si, Sc, Ti, Cr, Fe, Ni, and Zn induced by electron bombardment. The research includes the Kβ^III and Kβ^IV spectator hole transitions, the 1s→3s quadrupole decay, the Kβ₂ and Kβ₅ diagram transitions, the structures related to radiative Auger processes, and the Kβ' and Kβ" lines. For more information, see the paper, "Kβ satellite and forbidden transitions in elements with 12A81, 012504 (2010).

Diamond as a promising candidate for normal-incidence X-ray optics

2010-01-16T17:39:34Z

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.

Resonant X-ray scattering with microbeam to explore liquid crystal

2010-01-11T17:39:13Z

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).

Possibility of downsizing X-ray free electron laser

2010-01-11T17:39:02Z

Laser sources in the hard X-ray region have already become a reality at some free electron laser (FEL) facilities. However, typical hard X-ray FELs use an accelerator that is several km long to generate a ~10 GeV electron beam with ~kA peak current to drive the FEL. Dr. D. Xiang (SLAC National Accelerator Laboratory, USA) is proposing an alternative technique to generate an electron beam. He discusses the possibility of downsizing an X-ray FEL by this method. In his calculation, a 1.5 Å X-ray FEL with a saturation length within 30 m using a 3.8 GeV electron beam could be feasible. For more information, see the paper, "Laser assisted emittance exchange: Downsizing the x-ray free electron laser", D. Xiang, Phys. Rev. ST Accel. Beams 13, 010701 (2010).

X-ray studies on dynamics of micro phase separation in a block copolymer melt

2010-01-06T17:39:43Z

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).

UK withdraws from European XFEL project

2009-12-15T17:39:03Z

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

Picoliter droplets as reference samples for quantitative micro X-ray fluorescence

2009-11-24T17:39:25Z

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).

Ultimate hard X-ray focusing

2009-11-21T17:39:31Z

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.

Kβ/Kα intensity ratio in Cr, Fe and Ni

2009-11-09T16:39:00Z

Dr. I. Han (Ağrı İbrahim Çeçen University, Turkey) and his colleagues have published a paper on the relationship between the Kβ/Kα X-ray fluorescence intensity ratio and valence-electron configurations. For more information, see the paper, "Valence-electron configuration of Fe, Cr, and Ni in binary and ternary alloys from Kβ-to-Kα X-ray intensity ratios", I. Han et al., Phys. Rev. A80, 052503 (2009).

X-ray reflectivity analysis of self assembled nano patterns

2009-11-08T16:39:00Z

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).

The 4th Asada award and the special award 2009

2009-11-04T16:39:00Z

The recipient of the 4th Asada Award, which is presented in memory of the late Professor Ei-ichi Asada (1924-2005) to promising young scientists in X-ray analysis fields in Japan, is Dr. Akiko Hokura (Tokyo Denki Univ., "Study on accumulation of heavy metals in phytoremediation plant by synchrotron radiation micro XRF imaging and XAFS analysis"). From this year, the Discussion Group of X-ray Analysis, the Japan Society for Analytical Chemistry decided to establish the special award to recognize scientists who exhibit outstanding achievement and make a substantial contribution to the advancement of the X-ray analysis field. The recipient of the special award 2009 is Dr. Toshio Shiraiwa, who contributed greatly in the early days of X-ray absorption spectroscopy by means of his short-range order theory ("The theory of the fine structure of the X-ray absorption spectrum", J. Phys. Soc. Jpn. 13, 847 (1958)) and also provided the basis of the fundamental parameter method in X-ray fluorescence by Fujino-Shiraiwa's formula ("Theoretical calculation of fluorescent X-ray intensities in fluorescent X-ray spectrochemical analysis", Jpn. J. Appl. Phys. 5, 886 (1966)) The ceremony was held during the 45th Annual Conference on X-Ray Chemical Analysis, Japan, at Osaka City University, Osaka.

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

A method for evaluating the spatial coherence of an X-ray beam

2009-11-04T16:39:00Z

Professors T. Narayanan (ESRF, Grenoble, France), M. Giglio (XFEL, Hamburg, Germany) and their collaborators have recently published an interesting paper on a novel method to map the two-dimensional transverse coherence of an X-ray beam. The technique uses the dynamical near-field speckles formed by scattering from colloidal particles, which are executing Brownian motions. It is possible to measure the change of the interference fringes, and consequently the fluctuation of speckles. It was found that the coherence properties of synchrotron radiation from an undulator source are obtained with high accuracy. For more information, see the paper, "Probing the transverse coherence of an undulator X-ray beam using Brownian particles", M. D. Alaimo et al., Phys. Rev. Lett., 103, 194805 (2009).