TY - JOUR A1 - Bjeoumikhov, A. A1 - Arkadiev, V. A1 - Eggert, F. A1 - Hodoroaba, Vasile-Dan A1 - Langhoff, N. A1 - Procop, Mathias A1 - Rabe, J. A1 - Wedell, R. T1 - A new microfocus x-ray source, iMOXS, for highly sensitive XRF analysis in scanning electron microscopes JF - X-ray spectrometry N2 - Scanning electron microscopes are usually equipped with energy-dispersive X-ray detectors for electron probe microanalysis. This widespread analytical method allows investigators to determine the elemental composition of specimens with a spatial resolution of about 1 µm. However, owing to the electron-specimen interaction, the emitted spectra reveal, in addition to characteristic lines, also a high level of continuous bremsstrahlung background. As a result, elements with low concentrations cannot be identified. The minimum detection limit can be diminished by two orders of magnitude if the characteristic lines are excited as fluorescence by an additional x-ray source. In this case, the emergence of bremsstrahlung is considerably reduced. Combining a high-brilliance microfocus x-ray tube with efficient polycapillary optics enables one to realize an experimental arrangement for performing local fluorescence analysis at the same point where the electron beam hits the sample. The polycapillary optics under consideration focuses the emitted x-radiation onto focal spots between 30 and 100 µm in diameter. Count rates of several thousands cps have been achieved. Elemental maps have been obtained by means of the motorized specimen stage of the microscope. Copyright © 2005 John Wiley & Sons, Ltd. KW - Micro-XRF KW - Microfocus x-ray source KW - EPMA KW - SEM PY - 2005 DO - https://doi.org/10.1002/xrs.872 SN - 0049-8246 VL - 34 IS - 6 SP - 493 EP - 497 PB - Wiley CY - Chichester AN - OPUS4-11228 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Bjeoumikhov, A. T1 - Calculation of X-ray spectra for a side window tube JF - Microscopy and microanalysis T2 - Microscopy and Microanalysis CY - Chicago, IL, United States of America DA - 2006-07-30 KW - X-ray spectroscopy KW - X-ray tube KW - Microanalysis KW - XRF PY - 2006 DO - https://doi.org/10.1017/S143192760606123X SN - 1431-9276 SN - 1435-8115 VL - 12 IS - Supplement 2 PB - Cambridge University Press CY - New York, NY AN - OPUS4-12667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, Zemfira A1 - Riesemeier, Heinrich A1 - Radtke, Martin A1 - Wedell, R. T1 - Propagation of synchrotron radiation through nanocapillary structures JF - Physics letters A N2 - The propagation of synchrotron radiation through nanocapillary structures with channel sizes of 200 nm and periods in the micrometer size has been studied experimentally. It was shown that the propagation through individual capillary channels has a mode formation character. Furthermore it was shown that during the propagation through capillary channels the coherence of synchrotron radiation is partially conserved. Interference of beams propagating through different capillary channels is observed which leads to a periodically modulated distribution of the radiation intensity in a plane far from the exit of the structure. These investigations are of high relevance for the understanding of X-ray transmission through nanocapillaries and the appearance of wave properties at this size scale. KW - Polycapillary structure KW - Nanocapillary KW - X-ray optics KW - Wave properties KW - Synchrotron radiation KW - X-ray diffraction PY - 2007 DO - https://doi.org/10.1016/j.physleta.2007.01.092 SN - 0031-9163 SN - 0375-9601 VL - 366 IS - 4-5 SP - 283 EP - 288 PB - North-Holland Publ. Co. CY - Amsterdam AN - OPUS4-20580 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Snigirev, A. A1 - Bjeoumikhov, A. A1 - Erko, a. A1 - Snigireva, I. A1 - Grigoriev, M. A1 - Yunkin, V. A1 - Erko, M. A1 - Bjeoumikhova, Zemfira T1 - Submicrometer hard X-ray focusing using a single-bounce ellipsoidal capillary combined with a Fresnel zone plate JF - Journal of synchrotron radiation N2 - A single-bounce capillary with an ellipsoidal shape has been used for two-step focusing in combination with a Fresnel zone plate (FZP). The FZP serves as a first microfocusing element and produces a demagnified micrometer image of the source, before the elliptical capillary makes a last final compression of the beam. With 15 keV X-rays from the European Synchrotron Radiation Facility BM5 bending magnet, the two-step demagnification system produced a focus of about 250 nm with a gain of more than 1000. The use of an ellipsoidal capillary as a micro-mirror under off-axis illumination using micro-prefocusing optics might open up new opportunities in nanofocusing developments. KW - Hard X-ray focusing KW - Single-bounce capillary KW - Fresnel zone plate PY - 2007 DO - https://doi.org/10.1107/S0909049507004050 SN - 0909-0495 SN - 1600-5775 VL - 14 IS - 2 SP - 227 EP - 228 PB - Blackwell Publishing CY - Oxford AN - OPUS4-20581 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bjeoumikhov, A. A1 - Erko, M. A1 - Bjeoumikhova, Zemfira A1 - Erko, A. A1 - Snigireva, I. A1 - Snigirev, A. A1 - Wolff, Timo A1 - Mantouvalou, I. A1 - Malzer, W. A1 - Kanngießer, B. T1 - Capillary µFocus X-ray lenses with parabolic and elliptic profile JF - Nuclear instruments and methods in physics research A KW - Synchrotron radiation KW - Capillary optics KW - Beamline optics PY - 2008 DO - https://doi.org/10.1016/j.nima.2008.01.087 SN - 0168-9002 SN - 0167-5087 VL - 587 IS - 2-3 SP - 458 EP - 463 PB - North-Holland CY - Amsterdam AN - OPUS4-18922 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Procop, Mathias A1 - Hodoroaba, Vasile-Dan A1 - Bjeoumikhov, A. A1 - Wedell, R. A1 - Warrikhoff, A. T1 - Improvements of the low-energy performance of a micro-focus x-ray source for XRF analysis with the SEM JF - X-ray spectrometry N2 - X-ray Fluorescence (XRF) with a scanning electron microscope (SEM) is a valuable completion of the analytical capabilities of SEMs. Small and compact micro-focus x-ray sources are mounted to the microscope chamber, and the x-ray spectra are monitored with conventional EDS systems. Up to now the x-ray tubes used for the micro-focus x-ray sources are equipped with beryllium windows about 100 µm thick. The poly-capillary x-ray lenses have their transmission maximum at photon energies around 10 keV. It drops down in both low- and high-energy ranges. Hence, L-radiation from an Mo or Rh target will be strongly attenuated, and the excitation of fluorescence in the soft x-ray range becomes very ineffective. A new micro-focus x-ray source was developed. It is characterised by a lower self-absorption in the tube target, thin beryllium windows and an x-ray optics having a large distance between its foci and the maximum of transmission at about 5 keV. Thus K line fluorescence of light elements becomes effectively excited by the L-radiation from Mo or Rh tube targets. The detection limit for sodium oxide in glass was found to be below 1 mass%. KW - Micro-focus-XRF KW - X-ray tube KW - X-ray optics KW - SEM PY - 2009 DO - https://doi.org/10.1002/xrs.1159 SN - 0049-8246 VL - 38 IS - 4 SP - 308 EP - 311 PB - Wiley CY - Chichester AN - OPUS4-19583 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ordavo, I. A1 - Ihle, S. A1 - Arkadiev, V. A1 - Scharf, Oliver A1 - Soltau, H. A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, S. A1 - Buzanich, Günter A1 - Gubzhokov, R. A1 - Günther, A. A1 - Hartmann, R. A1 - Holl, P. A1 - Kimmel, N. A1 - Kühbacher, M. A1 - Lang, M. A1 - Langhoff, N. A1 - Liebel, A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Schaller, G. A1 - Schopper, F. A1 - Strüder, L. A1 - Thamm, C. A1 - Wedell, R. T1 - A new pnCCD-based color X-ray camera for fast spatial and energy-resolved measurements JF - Nuclear instruments and methods in physics research A N2 - We present a new high resolution X-ray imager based on a pnCCD detector and a polycapillary optics. The properties of the pnCCD like high quantum efficiency, high energy resolution and radiation hardness are maintained, while color corrected polycapillary lenses are used to direct the fluorescence photons from every spot on a sample to a corresponding pixel on the detector. The camera is sensitive to photons from 3 to 40 keV with still 30% quantum efficiency at 20 keV. The pnCCD is operated in split frame mode allowing a high frame rate of 400 Hz with an energy resolution of 152 eV for Mn Kα (5.9 keV) at 450 kcps. In single-photon counting mode (SPC), the time, energy and position of every fluorescence photon is recorded for every frame. A dedicated software enables the visualization of the elements distribution in real time without the need of post-processing the data. A description of the key components including detector, X-ray optics and camera is given. First experiments show the capability of the camera to perform fast full-field X-Ray Fluorescence (FF-XRF) for element analysis. The imaging performance with a magnifying optics (3×) has also been successfully tested. KW - X-ray CCD camera KW - pnCCD KW - Fast X-ray imaging KW - XRF KW - Full-field X-ray fluorescence KW - Elemental analysis KW - High quantum efficiency KW - High energy resolution KW - Polycapillary optics PY - 2011 DO - https://doi.org/10.1016/j.nima.2011.05.080 SN - 0168-9002 SN - 0167-5087 VL - 654 SP - 250 EP - 257 PB - North-Holland CY - Amsterdam AN - OPUS4-24370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ostermann, Markus A1 - Kühn, Andreas A1 - Bjeoumikhov, A. A1 - Wedell, R. T1 - Einsatz der Röntgenfluoreszenzanalyse in der Prozessanalytik JF - Technisches Messen N2 - Elementanalyse mit Röntgenfluoreszenzspektrometrie direkt am Materialstrom in Produktionsprozessen gewinnt zunehmend an Bedeutung. Die Röntgenfluoreszenzspektrometrie kann aufgrund der technischen Entwicklung mittlerweile ohne aufwändige Probenvorbereitung als aussagekräftige Informationsquelle für Stoffparameter im industriellen Prozess eingesetzt werden. Der Einsatz von online Röntgenfluoreszenzanalyse zahlt sich sowohl finanziell als auch zeitlich schnell aus, da sie sowohl für den ökonomischen Einsatz von Rohmaterialien, als auch z. B. im Materialrecycling zu gebrauchen ist. In diesem Beitrag werden vier unterschiedliche Einsatzmöglichkeiten beschrieben. N2 - Elemental analysis directly at the material stream of production processes using X-ray fluorescence spectrometry is gathering importance. Thanks to technical developments, X-ray fluorescence analysis can be used as information source in the elemental analysis of material in industrial processes without tedious sample preparation steps. The employment of online X-ray fluorescence analysis pays off both in financial as well in time aspects, since it can be used for the economic application of raw materials or e. g. for recycling. This paper describes four different applications of X-ray fluorescence spectroscopy. KW - Röntgenfluoreszenzspektrometrie KW - Stoffparameter KW - Materialanalyse KW - X-ray fluorescence spectrometry KW - Elemental analysis KW - Material analysis PY - 2011 DO - https://doi.org/10.1524/teme.2011.0162 SN - 0340-837X SN - 0178-2312 SN - 0171-8096 VL - 78 IS - 12 SP - 559 EP - 568 PB - Oldenbourg CY - München AN - OPUS4-24973 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Scharf, Oliver A1 - Ihle, S. A1 - Ordavo, I. A1 - Arkadiev, V. A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, S. A1 - Buzanich, Günter A1 - Gubzhokov, R. A1 - Günther, A. A1 - Hartmann, R. A1 - Kühbacher, M. A1 - Lang, M. A1 - Langhoff, N. A1 - Liebel, A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Soltau, H. A1 - Strüder, L. A1 - Thünemann, Andreas A1 - Wedell, R. T1 - Compact pnCCD-based X-ray camera with high spatial and energy resolution: a color X-ray camera JF - Analytical chemistry N2 - For many applications there is a requirement for nondestructive analytical investigation of the elemental distribution in a sample. With the improvement of X-ray optics and spectroscopic X-ray imagers, full field X-ray fluorescence (FF-XRF) methods are feasible. A new device for high-resolution X-ray imaging, an energy and spatial resolving X-ray camera, is presented. The basic idea behind this so-called 'color X-ray camera' (CXC) is to combine an energy dispersive array detector for X-rays, in this case a pnCCD, with polycapillary optics. Imaging is achieved using multiframe recording of the energy and the point of impact of single photons. The camera was tested using a laboratory 30 µm microfocus X-ray tube and synchrotron radiation from BESSY II at the BAMline facility. These experiments demonstrate the suitability of the camera for X-ray fluorescence analytics. The camera simultaneously records 69696 spectra with an energy resolution of 152 eV for manganese Kα with a spatial resolution of 50 µm over an imaging area of 12.7 × 12.7 mm². It is sensitive to photons in the energy region between 3 and 40 keV, limited by a 50 µm beryllium window, and the sensitive thickness of 450 µm of the chip. Online preview of the sample is possible as the software updates the sums of the counts for certain energy channel ranges during the measurement and displays 2-D false-color maps as well as spectra of selected regions. The complete data cube of 264 × 264 spectra is saved for further qualitative and quantitative processing. KW - Color X-ray camera KW - X-ray fluorescence KW - pnCCD KW - Polycapillary optic KW - Synchrotron radiation PY - 2011 DO - https://doi.org/10.1021/ac102811p SN - 0003-2700 SN - 1520-6882 VL - 83 IS - 7 SP - 2532 EP - 2538 PB - American Chemical Society CY - Washington, DC AN - OPUS4-23948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Reiche, I. A1 - Muller, K. A1 - Alberic, M. A1 - Scharf, O. A1 - Wahning, A. A1 - Bjeoumikhov, A. A1 - Radtke, Martin A1 - Simon, R. T1 - Discovering vanished paints and naturally formed gold nanoparticles on 2800 years old Phoenician ivories using SR-FF-microXRF with the color X-ray camera JF - Analytical chemistry N2 - Phoenician ivory objects (8th century B.C., Syria) from the collections of the Badisches Landesmuseum, Karlsruhe, Germany, have been studied with full field X-ray fluorescence microimaging, using synchrotron radiation (SR-FF-microXRF). The innovative Color X-ray Camera (CXC), a full-field detection device (SLcam), was used at the X-ray fluorescence beamline of the ANKA synchrotron facility (ANKA-FLUO, KIT, Karlsruhe, Germany) to noninvasively study trace metal distributions at the surface of the archeological ivory objects. The outstanding strength of the imaging technique with the CXC is the capability to record the full XRF spectrum with a spatial resolution of 48 µm on a zone of a size of 11.9 × 12.3 mm² (264 × 264 pixels). For each analyzed region, 69696 spectra were simultaneously recorded. The principal elements detected are P, Ca, and Sr, coming from the ivory material itself; Cu, characteristic of pigments; Fe and Pb, representing sediments or pigments; Mn, revealing deposited soil minerals; Ti, indicating restoration processes or correlated with Fe sediment traces; and Au, linked to a former gilding. This provides essential information for the assessment of the original appearance of the ivory carvings. The determined elemental maps specific of possible pigments are superimposed on one another to visualize their respective distributions and reconstruct the original polychromy and gilding. Reliable hypotheses for the reconstruction of the original polychromy of the carved ivories are postulated on this basis. KW - SR-FF-microXRF KW - Elemental imaging KW - Ivory KW - Paints KW - Au NPs KW - Egyptian blue KW - Fe PY - 2013 DO - https://doi.org/10.1021/ac4006167 SN - 0003-2700 SN - 1520-6882 VL - 85 IS - 12 SP - 5857 EP - 5866 PB - American Chemical Society CY - Washington, DC AN - OPUS4-30222 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -