TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Radtke, Martin A1 - Vincze, L. A1 - Rackwitz, Vanessa A1 - Reuter, Dirk T1 - X-ray scattering in X-ray fluorescence spectra with X-ray tube excitation - Modelling, experiment, and Monte-Carlo simulation N2 - X-ray scattering may contribute significantly to the spectral background of X-ray fluorescence (XRF) spectra. Based on metrological measurements carried out with a scanning electron microscope (SEM) having attached a well characterised X-ray source (polychromatic X-ray tube) and a calibrated energy dispersive X-ray spectrometer (EDS) the accuracy of a physical model for X-ray scattering is systematically evaluated for representative samples. The knowledge of the X-ray spectrometer efficiency, but also of the spectrometer response functions makes it possible to define a physical spectral background of XRF spectra. Background subtraction relying on purely mathematical procedures is state-of-the-art. The results produced by the analytical model are at least as reliable as those obtained by Monte-Carlo simulations, even without considering the very challenging contribution of multiple scattering. Special attention has been paid to Compton broadening. Relevant applications of the implementation of the analytical model presented in this paper are the prediction of the limits of detection for particular cases or the determination of the transmission of X-ray polycapillary lenses. KW - X-ray scattering KW - X-ray fluorescence KW - Spectral background KW - Modelling KW - Monte-Carlo simulation PY - 2010 U6 - https://doi.org/10.1016/j.nimb.2010.09.017 SN - 0168-583X SN - 1872-9584 VL - 268 IS - 24 SP - 3568 EP - 3575 PB - Elsevier CY - Amsterdam AN - OPUS4-22357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rakotondrajoa, Andrianiaina A1 - Buzanich, Günter A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vincze, L. A1 - Raboanary, R. T1 - Improvement of PLS regression-based XRF spectroscopy quantification using multiple step procedure and Monte Carlo simulation N2 - Partial least squares (PLS) regression-based methods have been proven to be a good alternative for quantification in X-ray fluorescence spectroscopy. These methods are fast and easy to use though giving satisfactory results under certain conditions. One of these conditions is the necessity of having a great number of spectra to build the model (training set). The choice of the constituent concentration range in the training set has a big influence on the accuracy of the model. Better accuracy is obtained if the model is built in relatively narrow regions containing (or close to) the real concentration value. In the present work, Monte Carlo (MC) simulated spectra are used to form the training set. The advantage to use MC generated training spectra is the unlimited availability of perfect standards. This paper aims to improve the accuracy of the method by introducing a multiple step procedure in order to build the PLS model using narrow concentration range close to (or containing) the real concentration values in the samples to be measured. This approach consists of an initial guess of the constituents' concentrations and a preliminary PLS model before building the final model. The prediction of ten MC simulated alloy standard samples containing Ti, Mn, Fe, Co, Cu, Zn, Sr, Zr, and Mo using this method allowed to have average relative prediction errors less than 5% for elements with narrow concentration ranges. KW - SR-microXRF KW - Quantification KW - PLS KW - Monte Carlo PY - 2013 U6 - https://doi.org/10.1002/xrs.2479 SN - 0049-8246 VL - 42 IS - 4 SP - 183 EP - 188 PB - Wiley CY - Chichester AN - OPUS4-30225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radtke, Martin A1 - Vincze, L. A1 - Görner, Wolf T1 - Quantification of energy dispersive SRXRF for the certification of reference materials at BAMline N2 - The certification of reference materials (CRMs) is one of the main tasks of the BAM Federal Institute for Materials Research and Testing. In this context CRMs for analytical chemistry play the dominant role. Traditionally, energy dispersive X-ray fluorescence (EDXRF) has been excluded from the final certification scheme. It has lacked the proof to be reliable enough due to peak overlapping and risks of incorrect background subtraction leading to unacceptable uncertainty and bias of the results. The development described aims at enabling ED-SRXRF to really contribute to certification by the aid of synchrotron radiation. This has been partly shown for macrocontents and has been successfully demonstrated for trace elements and thin layers. The method is based on a combination of measurements of pure elements or stoichiometric compounds as comparator materials and Monte Carlo simulations. Measurements have been performed at the BAMline, the hard X-ray beam line of the BAM at the synchrotron BESSY II in Berlin. KW - SyXRF Quantifizierung KW - Monte Carlo Simulation KW - Referenzmaterialien PY - 2010 U6 - https://doi.org/10.1039/b926596a SN - 0267-9477 SN - 1364-5544 VL - 25 IS - 5 SP - 631 EP - 634 PB - Royal Society of Chemistry CY - London AN - OPUS4-22895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hodoroaba, Vasile-Dan A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Riesemeier, Heinrich A1 - Vincze, L. A1 - Reuter, Dirk T1 - X-ray scattering in X-ray fluorescence spectra with X-ray monochromatic, polarised excitation - modelling, experiment, and Monte-Carlo simulation N2 - A systematic series of measurements has been carried out with monochromatic X-ray excitation with synchrotron radiation in order to check a physical model on X-ray scattering. The model has recently been successfully tested for the case of polychromatic, unpolarised excitation emitted by an X-ray tube. Our main purpose is the modelling of a physical background in X-ray fluorescence spectra, so that improved quantitative results can be achieved especially for strongly scattering specimens. The model includes single Rayleigh and Compton scattering in the specimen, the effect of bound electrons, the challenging Compton broadening and the polarisation degree. Representative specimens, measurement geometries and excitation energies have been selected with synchrotron monochromatic light at BAMline/BESSY II. Monte-Carlo simulations have been also carried out in order to evaluate the quality of the results achieved with the model. KW - X-ray scattering KW - Monochromatic excitation KW - Polarisation KW - Modelling KW - Monte-Carlo simulation PY - 2011 U6 - https://doi.org/10.1016/j.nimb.2011.04.009 SN - 0168-583X SN - 1872-9584 VL - 269 IS - 13 SP - 1493 EP - 1498 PB - Elsevier CY - Amsterdam AN - OPUS4-23765 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - De Samber, B. A1 - Scharf, Oliver A1 - Buzanich, Günter A1 - Garrevoet, J. A1 - Tack, P. A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Reinholz, Uwe A1 - Evens, R. A1 - De Schamphelaere, K. A1 - Falkenberg, G. A1 - Janssen, C. A1 - Vincze, L. T1 - Three-dimensional X-ray fluorescence imaging modes for biological specimens using a full-field energy dispersive CCD camera N2 - Besides conventional scanning X-ray fluorescence imaging at synchrotron sources, full-field X-ray fluorescence (FF-XRF) imaging techniques that do not implicitly require spatial scanning of the sample have become available. FF-XRF has become achievable thanks to the development of a new type of energy dispersive CCD-based 2D detector, also referred to as a 'color X-ray camera (CXC)' or 'SLcam'. We report on different imaging schemes for biological samples using FF-XRF imaging: (a) 2D 'zoom' imaging with pinhole optics using the 'camera obscura' principle; (b) 2D 'fixed magnification' imaging using magnifying polycapillary optics; and (c) 3D-FF-XRF imaging using an X-ray sheet beam or computed tomography (CT). The different FF-XRF imaging modes are illustrated using the crustacean Daphnia magna, a model organism for investigating the effects of metals on organism/ecosystem health, and foraminifera, a class of amoeboid protist. Detailed analytical characterization of the set-up is performed through analyzing various reference materials in order to determine limits of detection (LODs) and sensitivities. Experiments were performed using the BAMline at the BESSY synchrotron (Berlin, Germany) and using the P06 Hard X-ray Microprobe at the PETRAIII synchrotron (Hamburg, Germany). KW - CXC KW - BAMline KW - Maia detector KW - Synchrotron PY - 2019 U6 - https://doi.org/10.1039/c9ja00198k VL - 34 IS - 10 SP - 2083 EP - 2093 PB - Royal Society of Chemistry CY - Cambridge, United Kingdom AN - OPUS4-49359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schoonjans, Tom A1 - Brunetti, A. A1 - Golosio, B. A1 - Sanchez del Rio, M. A1 - Solé, V. A. A1 - Ferrero, C. A1 - Vincze, L. T1 - xraylib 3.1.0 N2 - Quantitative estimate of elemental composition by spectroscopic and imaging techniques using X-ray fluorescence requires the availability of accurate data of X-ray interaction with matter. Although a wide number of computer codes and data sets are reported in literature, none of them is presented in the form of freely available library functions which can be easily included in software applications for X-ray fluorescence. This work presents a compilation of data sets from different published works and an xraylib interface in the form of callable functions. Although the target applications are on X-ray fluorescence, cross sections of interactions like photoionization, coherent scattering and Compton scattering, as well as form factors and anomalous scattering functions, are also available. xraylib provides access to some of the most respected databases of physical data in the field of x-rays. The core of xraylib is a library, written in ANSI C, containing over 40 functions to be used to retrieve data from these databases. This C library can be directly linked with any program written in C, C++ or Objective-C. Furthermore, the xraylib package contains bindings to several popular programming languages: Fortran 2003, Perl, Python, Java, IDL, Lua, Ruby, PHP and .NET, as well as a command-line utility which can be used as a pocket-calculator. Although not officially supported, xraylib has been reported to be useable from within Matlab and LabView. The source code is known to compile and run on the following platforms: Linux, Mac OS X, Solaris, FreeBSD and Windows. Development occurs on Github: http://github.com/tschoonj/xraylib Downloads are hosted by the X-ray Micro-spectroscopy and Imaging research group of Ghent University: http://lvserver.ugent.be/xraylib Version 3.1.0 release notes: - Database of commonly used radionuclides for X-ray sources added (new API: GetRadioNuclideDataByName, GetRadioNuclideDataByIndex, GetRadioNuclideDataList and FreeRadioNuclideData) - numpy Python bindings added, generated with Cython. Performance basically the same as the core C library. (suggested by Matt Newville) - docstring support added to Python bindings (suggested by Matt Newville) - Windows SDKs now have support for Python 3.4. - Windows 64-bit SDK now comes with IDL bindings - Confirmed support for LabView (thanks to Dariush Hampai!) - Universal Intel 32/64 bit Framework built for Mac OS X - Perl support for Debian/Ubuntu - Several bugfixes: thanks to those that reported them! KW - Quantitative estimation KW - Elemental composition KW - Spectroscopic techniques KW - Imaging techniques PY - 2014 U6 - https://doi.org/10.5281/zenodo.12378 PB - Zenodo CY - Geneva AN - OPUS4-51924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Schoonjans, Tom A1 - Vincze, L. A1 - Solé, V. A. A1 - Sanchez del Rio, M. A1 - Brondeel, P. A1 - Silversmit, G. A1 - Appel, K. A1 - Ferrero, C. T1 - XMI-MSIM 5.0 N2 - XMI-MSIM is an open source tool designed for predicting the spectral response of energy-dispersive X-ray fluorescence spectrometers using Monte-Carlo simulations. It comes with a fully functional graphical user interface in order to make it as user friendly as possible. Considerable effort has been taken to ensure easy installation on all major platforms. Development of this package was part of my PhD thesis. The algorithms were inspired by the work of my promotor Prof. Laszlo Vincze of Ghent University. Links to his and my own publications can be found in our manual. A manuscript has been published in Spectrochimica Acta Part B that covers the algorithms that power XMI-MSIM. Please include a reference to this publication in your own work if you decide to use XMI-MSIM for academic purposes. A second manuscript was published that covers our XMI-MSIM based quantification plug-in for PyMca. Soon information on using this plug-in will be added to the manual. XMI-MSIM is released under the terms of the GPLv3. Development occurs at Github: http://github.com/tschoonj/xmimsim Downloads are hosted by the X-ray Micro-spectroscopy and Imaging research group of Ghent University: http://lvserver.ugent.be/xmi-msim Version 5.0 release notes: Changes: 1. Custom detector response function: build a own plug-in containing your own detector response function and load it at run-time to override the builtin routines. Instructions can be found in the manual. 2. Escape peak improvements: new algorithm is used to calculate the escape peak ratios based on a combined brute-force and variance-reduction approach. Ensures high accuracy even at high incoming photon energies and thin detector crystals. Downside: it's slower… 3. Removed maximum convolution energy option. Was a bit confusing anyway. 4. Number of channels: moved from simulation controls into input-file 5. Radionuclide support added: Now you can select one or more commonly used radionuclide sources from the X-ray sources widget. 6. Advanced Compton scattering simulation: a new alternative implementation of the Compton scattering has been implemented based on the work of Fernandez and Scot (http://dx.doi.org/10.1016/j.nimb.2007.04.203), which takes into account unpopulated atomic orbitals. Provides an improved simulation of the Compton profile, as well as fluorescence contributions due to Compton effect (extremely low!), but slows the code down considerably. Advanced users only. Default: OFF 7. Plot spectra before convolution in results 8. Windows: new Inno Setup installers. Contains the headers and import libraries 9. Windows: compilers changed to GCC 4.8.1 (TDM-GCC) 10. Windows: rand_s used to generate seeds on 64-bit version (requires Vista or later) 11. Windows: new gtk runtime for the 64-bit version (see also https://github.com/tschoonj/GTK-for-Windows-Runtime-Environment-Installer) 12. Mac OS X: compilers changed to clang 5.1 (Xcode) and gfortran 4.9.1 (MacPorts) 13. Original input-files from our 2012 publication (http://dx.doi.org/10.1016/j.sab.2012.03.011) added to examples 14. Updater performs checksum verification after download 15. X-ray sources last used values stored in preferences.ini 16. xmimsimdata.h5 modified: even bigger now... Bugfixes: 1. Windows: support for usernames with unicode characters. Fixed using customized builds of HDF5. Thanks to Takashi Omori of Techno-X for the report! 2. Spectrum import from file fixes. Was never properly tested apparently Note: For those that compiled XMI-MSIM from source: you will need to regenerate the xmimsimdata.h5 file with xmimsim-db. Old versions of this file will not work with XMI-MSIM 5.0. KW - Spectral response KW - Energy-dispersive X-ray fluorescence spectrometers KW - Monte-Carlo simulations PY - 2014 U6 - https://doi.org/10.5281/zenodo.12381 PB - Zenodo CY - Geneva AN - OPUS4-51925 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -