A team led by Dr. T. Jach (NIST, USA) and Dr. W. T. Elam (University of Washington, USA) has recently published an interesting theoretical paper discussing the broadening of N K absorption and emission spectra of NH4NO3 and NH4Cl. The authors studied many-body lifetime effects in valence-band X-ray emission. For more information, see the paper, "Origins of extreme broadening mechanisms in near-edge x-ray spectra of nitrogen compounds", J. Vinson et al., Phys. Rev. B90, 205207 (2014).
The recipient of the 9th Asada Award, which is presented by the Discussion Group of X-ray Analysis, Japan, in memory of the late Professor Ei-ichi Asada (1924-2005) to promising young scientists in X-ray analysis fields in Japan, is Dr. Susumu Imashuku (Kyoto Univ.), "Portable electron probe microanalyzer using pyroelectric crystal". The ceremony was held during the 50th Annual Conference on X-Ray Chemical Analysis, at Tohoku University, Sendai.
So far, monochromatic X-rays have been used for 3D micro X-ray fluorescence analysis based on confocal geometry. Dr. P. Wrobel (AGH University of Science and Technology, Poland) and his colleagues have recently discussed the feasibility of polychromatic excitation. The research group described the full theoretical expression of matrix effects and geometrical effects for polychromatic X-ray photons in confocal arrangement. It was demonstrated that the introduction of effective energy approximation works well. For more information, see the paper, "Depth Profiling of Element Concentrations in Stratified Materials by Confocal Microbeam X-ray Fluorescence Spectrometry with Polychromatic Excitation", P. Wrobel et al., Anal. Chem., 86, 11275 (2014).
Professor L. Vincze (Ghent University, Belgium) and his colleagues have reported on the latest fluorescence mode XANES imaging using the SLcam, which is an energy dispersive pnCCD detector. At BM26A, ESRF, the measurements were done for iron foil with some oxides and geological standard samples. The typical detection limit and measuring time were 0.5 wt% and 15 h, respectively. Readers might think that energy-resolution can be sacrificed near the absorption edges of interest in order to shorten the measuring time in the same way as ordinary XANES measurement by means of X-ray fluorescence. Although the use of ordinary X-ray CCD in accumulation mode for a very similar experiment was published 10 years ago (for example, M. Mizusawa et al, J. Synchrotron Rad. 11, 209 (2004)), the present system has the advantage of being able to reduce the background from the major light elements contained in the sample. For more information, see the paper, "Full-Field Fluorescence Mode Micro-XANES Imaging Using a Unique Energy Dispersive CCD Detector", P. Tack et al, Anal. Chem., 86, 8791(2014).
Most X-ray experiments can be done at high quality with ease in an ordinary laboratory. Some experiments, however, have to be done in the field. It is hard to imagine a more extreme definition of "in the field" than the planet of Mars, which is why exciting times have come about since NASA's Mars rover "Curiosity" landed on Mars in August 2012. It has since recorded and sent back a large number of datasets including X-ray fluorescence (XRF) and X-ray diffraction (XRD) data. Naturally, the scientists involved with the projects have been speaking globally since. During EXRS 2014 (June, Bologna, Italy), Professor J. L. Campbell (University of Guelph, Canada) gave a keynote lecture entitled "XRF and PIXE on the Mars Science LAB Curiosity Rover". At the Denver X-ray conference (July, Big Sky, Montana), the Plenary Session was "X-rays on Mars", and 3 scientists gave lectures. Professor D. L. Bish (Indiana University) gave a talk entitled "The First X-ray Diffraction Results From Mars". Professor J. L. Campbell's talk on "XRF Combines with PIXE in Curiosity's Alpha Particle X-ray Spectrometer" was the extension on his talk at EXRS 2014, and further detailed and specific discussion was done there. Professor S.M. Clegg talked about "Exploring Mars with ChemCam on the Curiosity Rover" (ChemCam enables quick element determination by the laser-induced plasma emission spectroscopy). In August, at Montreal, during the International Union of Crystallography's congress, Professor D. L. Bish gave a talk entitled "The First X-ray Powder Diffraction Measurements on Mars". These talks highlighted many interesting technological aspects of the measurements: XRF analysis is done first by the same CCD camera, which works as an energy-dispersive 2D X-ray detector, even when the main aim of the measurement is obtaining the XRD pattern. In the analysis of unknown samples, generally both chemical composition and the crystal structure are indispensable. Another reason is that XRF helps the systematic use of single photon counting mode of the CCD camera to get a good quality XRD pattern. Secondly, the samples are vibrated all the time to ensure a smooth and continuous Debye ring. The rover furthermore contains a series of standard samples to check the reliability and reproducibility of the measurements. The readers might be interested in such a compact X-ray analyzer, which combined both XRD and XRF machine. Very similar system is now commercially available. For further information on the scientific activity on Mars, visit the Web page, http://mars.jpl.nasa.gov/msl/
Professor J. Wang (University of California San Diego, USA) and his colleagues have applied X-ray fluorescence to the analysis of gunshot residue, which has been usually detected based on the analysis trace amounts of metallic and organic species deposited on the hands, face, hair, and clothing of the shooter. The researchers tried to couple square-wave stripping voltammetry (SWSV) and scanning electron microscopy (SEM) plus energy dispersive X-ray spectroscopy (EDX). The former method can be used as a rapid screening tool, while the latter contributes to confirmation of the presence of the characteristic morphology and metal composition of gunshot residue particles. For more information, see the paper, "Orthogonal Identification of Gunshot Residue with Complementary Detection Principles of Voltammetry, Scanning Electron Microscopy, and Energy-Dispersive X-ray Spectroscopy: Sample, Screen, and Confirm", A. M. O'Mahony et al., Anal. Chem., 86, 8031 (2014).
During the plenary session of the 65th Annual Denver X-Ray Conference, two awards were presented. The 2014 Birks Award was presented to George Havrilla, Los Alamos National Laboratory for his many contributions to microXRF, especially the development of the confocal XRF microscope. Dr. Havrilla has been a leader in the field of analytical XRF; including 19 years on the Denver X-ray Conference Organizing Committee; nine years as North American Editor of X-ray Spectrometry; and six years as Co-Editor-in-Chief for Advances in X-ray Analysis. The ICDD Fellow Award was presented to John Getty, Instructor in Geophysical Engineering and Principal Investigator in the Proppant Research Group at Montana Tech. John has played a key role in the planning and execution of the Denver X-ray Conference for more than 30 years. For further information, visit the Web page, http://www.dxcicdd.com/
It is now known that X-ray free-electron lasers can produce ultrafast X-ray pulses as short as 3 fs in FWHM. Scientists at the Linac Coherent Light Source (LCLS), Stanford are trying to reduce delay time errors in optical-pump & X-ray probe measurements to the 1 fs level, by 2D spectrogram measurement of the relative X-ray/optical delay. For more information, see the paper, "Sub-femtosecond precision measurement of relative X-ray arrival time for free-electron lasers", N. Hartmann et al., Nature Photonics, 8, 706 (2014).
Dr. V-D. Hodoroaba (BAM, Berlin, Germany) and his colleague have published a report on the feasibility of quantitative X-ray fluorescence (XRF) analysis using coherent (Rayleigh) and incoherent (Compton) X-ray scattering. They have evaluated the ratio of the Compton-to-Rayleigh intensity observed in XRF spectra and also have discussed its relation to the average atomic number. In so-called reference-free XRF analysis, which uses only fundamental parameters and a theoretical formula and does not rely on the calibration curve, there still exist many difficulties, particularly for matrices of lower mean atomic numbers. The analysis presented in this research has sufficiently high sensitivity to distinguish the average atomic number of specimens even within the 0.1 difference. For more information, see the paper, "Gaining Improved Chemical Composition by Exploitation of Compton-to-Rayleigh Intensity Ratio in XRF Analysis", V-D. Hodoroaba et al., Anal. Chem., 86, 6858 (2014).
far, laser combs in visible light wavelength have been known as an extremely
precise measure of dimensions. What
would happen if they move into the X-ray region? The advent of an X-ray free electron laser
(XFEL) may realize an X-ray frequency comb in the near future. Dr. S. M. Cavalettobe (Max-Planck-Institut
Lecture Date: Tuesday May 27, 2014. Dr. Johanna Nelson Weker, SLAC, delivered the SLAC public lecture, "X-rays Reveal Secret Life of Batteries" (https://www.youtube.com/watch?v=V8lSTLRkKEk)
The use of X-ray free-electrons has enabled plenty of fascinating science, such as watching non-equilibrium excited-state dynamics in complexes of 3d transition metals. Scientists at LCLS, Stanford have performed femtosecond resolution X-ray fluorescence spectroscopy, with its sensitivity to spin state, elucidating the spin crossover dynamics of [Fe(2, 2ˈ-bipyridine)3]2+ on photoinduced metal-to-ligand charge transfer excitation. For more information, see the paper, "Tracking excited-state charge and spin dynamics in iron coordination complexes", W. Zhang et al., Nature, 509, 345 (2014).
K. Binnemans (KU Leuven,
An interesting and useful tutorial on X-ray analytical methods for newcomers is now available in the Materials Today Podcast. Dr. Ravi Yellepeddi (Thermo Fisher Scientific) explains the principle of X-ray fluorescence, recent progress in instruments, and the variety of applications in industry and research laboratories. The talk is around 30 min. Visit the following Web site,
application of confocal micro-X-ray fluorescence has been reported by Dr. Tianxi
Union of Crystallography (IUCr) has announced that Professors A. Janner and T. W.
J. M. Janssen (both from the Institute for Theoretical Physics, University of
Nijmegen, The Netherlands) have been awarded the tenth Ewald prize for the
development of superspace crystallography and its application to the analysis
of aperiodic crystals. The presentation
of the Ewald Prize will be made during the Montreal Congress Opening Ceremony
on 5 August 2014. The Ewald prize
consists of a medal, a certificate and an award of USD 30,000. Former recipients are E. Dodson (UK), C.
Giacovazzo (Italy), G. M. Sheldric (Germany) in 2011, D. Sayre (
Lecture Date: Tuesday October 1, 2013. Jennifer Mass of the Winterthur Museum in Wilmington, Delaware, delivered the SLAC public lecture, "Don't Fade Away: Saving the Vivid Yellows of Matisse and Van Gogh." (https://www.youtube.com/watch?v=RiASAbniQYw)
recipient of the 8th Asada Award, which is presented by the Discussion Group of
the plenary session of the 63rd Annual Denver X-Ray Conference, three
awards were presented. The 2013 Barrett
Award was presented to Vaclav Petricek of the Institute of Physics, Academy of
Sciences of the Czech Republic, Praha, Czech Republic, for developing the
theory of incommensurate/modulated/composite crystal structures and its
implementation in the computing system Jana2006 (the most widely-used system
for solving and refining aperiodic structures), and for making possible the
correct archival of such structures in the Powder Diffraction FileTM". The 2013 Jenkins Award was presented to Rene
Van Grieken of the
The Advanced Photon Source (APS) and APS Users Organization have announced that the 2013 Arthur H. Compton Award has been presented jointly to David E. Moncton, John N. Galayda, Michael Borland, and Louis Emery. The award recognizes the recipients' visionary leadership and technical ingenuity in introducing "top-up" operation to the synchrotron radiation community. The award consists of a plaque and $2500. Former recipients of this award are: Edward Stern, Farrel Lytle, Dale Sayers (posthumously), John Rehr (2011); Simon Mochrie, Mark Sutton, Gerhard Grubel (2009); Andrzej Joachimiak, 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).
The construction of Brookhaven's National Synchrotron Light Source II is approaching its final stage. Recently the last of 150 magnet girders was installed in the storage ring. Magnets traveled from across the globe, supplied by ring magnet vendors based in six countries: Buckley Systems Ltd (New Zealand), Budker Institute of Nuclear Physics (Russia), Danfysik (Denmark), Everson Tesla Incorporated (U.S.), Institute of High Energy Physics (China), and Tesla Engineering (U.K.). In the experimental hall, meanwhile, 17 hutches have been delivered and constructed for seven beamlines; CSX1 and CSX2 (two branches of Coherent Soft X-ray Scattering and Polarization), CHX (Coherent Hard X-ray Scattering), IXS (Inelastic X-ray Scattering), HXN (Hard X-ray Nanoprobe), SRX (Submicron Resolution X-ray Spectroscopy) and XPD (X-ray Powder Diffraction). For further information, visit the Web page, http://www.bnl.gov/ps/news/news.php?a=23725
An explanation of the CSX beamline construction can be viewed on You Tube.
Dr. B. Kanngießer (Technische Universität
The extremely high peak power of an X-ray free electron laser pulse can be an attractive tool for clarifying the core-level excitation and relaxation process. Recently, Dr. B. Rudek and his colleagues have reported their time-of-flight ion spectroscopy studies on sequential inner-shell multiple ionization of krypton at photon energies at 2 keV and 1.5 keV, which are higher than the LI (~1.92 keV) and lower than the LIII (~1.67 keV) edges for ordinary neutral krypton, respectively. The experiments were done with two X-ray pulse widths (5 and 80 fs) and various pulse energies (from 0.07 to 2.6 mJ), at the Linac Coherent Light Source (LCLS), Stanford,
In spite of the recent advent of few fs pulse X-ray free-electron laser sources, so far, synchronization between optical lasers and X-ray pulses has been challenging, and the jitter, typically, 100~200 fs r.m.s., has limited the time-resolution of the measurement. At the Linac Coherent Light Source (LCLS), Stanford, scientists have recently solved this problem by introducing a "measure-and-sort" approach, which records all single-shot data with time information to ensure resorting of the data. In the beamline, the same optical laser beam is split into three beams: with the first, the relative delay between laser and X-ray is encoded into wavelength by using a broadband chirped supercontinuum; in the second, the temporal delay is spatially encoded; in the third, pump-probe experiments are performed with time-sorting tools. It was concluded that the error in the delay time between optical and X-ray pulses can be substantially improved to 6 fs r.m.s., leading to time-resolved measurement with only a few fs resolution. For more information, see the paper, "Achieving few-femtosecond time-sorting at hard X-ray free-electron lasers", M. Harmand et al., Nature Photonics, doi:10.1038/nphoton.2013.11; published online, February 17, 2013.
One promising application of laser-matter interactions is generating hot suprathermal electrons with keV-MeV energy, which enables excitation of the K shell of the target material. Recently, Dr. G. Cristoforetti (Intense Laser Irradiation Laboratory,
Coherent X-ray diffractive imaging has made remarkable progress over the past 15 years. The technique basically reconstructs real space microscopic images with the spatial resolution of nm without the use of lenses, mainly because of the ability to retrieve phases. However, it relies on the degree of high coherence of the available X-ray photon beam, and, until now, almost all experimental studies have been subject to some limits. It is not very easy to satisfy the ideal conditions, mainly because of the partial coherence of the beam itself and some decoherence caused by imperfect detection as well as the dynamic motions of the sample. Dr. P. Thibaut (Technische Universität München,
The Science and Technology Foundation of Japan has announced that three
some readers already know Dr. Ken Lea's synchrotron song, but now it is
available on YouTube. The song is about synchrotron radiation and many
scientific studies, which have been done at The Synchrotron Radiation Source
(SRS), Daresbury Laboratory in
In Japan, a research team led by Professor K. Yamauchi (Osaka University) and Professor T. Ishikawa (Riken, Harima, Japan) has recently succeeded in focusing ultra short X-ray laser pulses from the SPring-8 Angstrom Compact free electron LAser (SACLA). With reflective optics comprising elliptically figured mirrors with nm accuracy to preserve a coherent wavefront, they have obtained a focused small beam of 0.95 × 1.20 μm2 at 10 keV. The estimated achievable power density at the sample position is 6 × 1017 W/cm2. For more information, see the paper, "Focusing of X-ray free-electron laser pulses with reflective optics", H. Yumoto et al., Nature Photonics, 7, 43 (2013).