TY - CONF A1 - Radtke, Martin A1 - Berger, Achim T1 - Tragbare RFA an Gläsern: Ergebnisse und Grenzen N2 - Vorstellung der Ergebnisse der Messungen an Gläsern von Goethes Prismen. T2 - 3. Goethe/Ritter-Workshop CY - Berlin, Germany DA - 25.05.2018 KW - Goethe KW - Farbenlehre KW - Prisma KW - Handheld KW - XRF PY - 2018 AN - OPUS4-46369 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witte, Steffen A1 - Kulow, Anicó A1 - Seeberg, D. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Grunewald, Christian A1 - Riesemeier, Heinrich A1 - Wohlrab, S. T1 - S2XAFS@work: Customization for the Characterization of VOx based Catalysts N2 - X-ray absorption fine structure spectroscopy (XAFS) is a frequently employed technique in order to investigate structural composition and change of chemical compounds such as catalytic species. These structural properties are essential (i) to understand underlying reaction mechanism and (ii) to further improve the design of efficient catalysts. This investigation is based on a newly developed XAFS setup comprising both time- and lateral-resolved XAFS information simultaneously in a single-shot (S2XAFS). The primary broadband beam is generated by a filter/X-ray-mirror combination (bandpass). The transmitted beam through the sample is diffracted by a convexly bent Si (111) crystal, producing a divergent beam. This, in turn, is collected by an area sensitive detector with a theta to 2 theta geometry. This facile, stable and scanningless setup was tested at the BAMline @ BESSY-II (Berlin, Germany). This contribution focuses on further experimental optimizations allowing the characterization of supported vanadium oxide (VOx) based catalysts at the lower hard X-ray regime (5 to 6 keV). First S2XAFS measurements of these catalysts are presented herein. Supported VOx catalysts show promising results in the oxidation of methane to formaldehyde. S2XAFS allows determining the structural composition of the metal (i.e. vanadium) based on a fast and smart setup. It is therefore an ideal tool to identify crucial roles of chemical compounds in catalytic reactions. T2 - XAFS 2018 CY - Cracow, Poland DA - 22.07.2018 KW - XANES KW - XAFS KW - BAMline KW - Synchrotron PY - 2018 AN - OPUS4-46362 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulow, Anicó A1 - de Oliveira Guilherme Buzanich, Ana A1 - Reinholz, Uwe A1 - Radtke, Martin A1 - Riesemeier, Heinrich A1 - Streli, C. T1 - Time- and lateral-resolved X-ray absorption fine structure spectroscopy N2 - We developed a setup for time- and lateral-resolved X-ray absorption fine structure (XAFS) spectroscopy. A dispersive element is placed behind the sample to investigate. The broadband incoming beam transmits the sample, is then dispersed and finally collected by a position sensitive detector. This allows the recording of a whole X-ray absorption near edge structure (XANES) or extended X-ray absorption fine structure (EXAFS) spectrum in a single shot. The dispersive element is a Si(111) crystal, bent by means of a so called wafer bender, developed in house. Our setup is very flexible, easy to adjust and allows a time resolution down to one second which can be used to follow chemical reactions with dynamics on this time scale. T2 - SXR2019 CY - Berlin, Germany DA - 16.09.2019 KW - Spectroscopy KW - X-ray KW - Absorption KW - Synchrotron PY - 2019 AN - OPUS4-49045 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kulow, Anicó A1 - Reinholz, Uwe A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Streli, C. A1 - Radtke, Martin T1 - X-ray fluorescence imaging with coded apertures N2 - We developed a new method for full field X-ray fluorescence imaging at the BAMline @ BESSY II. We combined an energy dispersive array detector for X-rays with a coded aperture to get high resolution images. In coded aperture imaging, an object is projected through a mask, producing many overlapping images on the detector. To get the information about the investigated object out of the projected image, a decoding step is necessary. The first part of our project was to develop the decoding algorithms. We tested the reported reconstruction with an antimask and compared the results with the performance of self-written reconstruction programs based on an iterative and a genetic algorithm. First tests were performed with raytracing simulations. The next step was the collection of experimental data at the BAMline @ BESSY II (HZB). A test objects could be successfully reconstructed with our newly developed algorithm. T2 - PRORA 2019 CY - Berlin, Germany DA - 28.11.2019 KW - X-ray KW - Imaging KW - Fluorescence KW - Coded apertures PY - 2019 AN - OPUS4-49963 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Witte, Steffen A1 - de Oliveira Guilherme Buzanich, Ana A1 - Fittschen, U.E.A. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Wobrauschek, P. A1 - Streli, C. T1 - TXRF-XANES: a unique experimental setup for chemical speciation of traces down to pg range N2 - Description of the set-up and first results for TXRF-XANES at BAMline T2 - XAFS 2018 CY - Cracow, Poland DA - 22.07.2018 KW - TXRF KW - XANES KW - Synchrotron KW - BAMline PY - 2018 AN - OPUS4-46363 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - From Egypt to Hiddensee – Analysis of Gold with Synchrotron Radiation IV N2 - Gold is one of the seven metals already known in antiquity and was used from time immemorial as a medium of exchange and for the production of jewelry because of its luster and rarity. In addition, it is easy to work and largely resistant to chemical influences. Investigations of gold using synchrotron radiation excited X-ray fluorescence analysis are non-destructive and provide information about the chemical elements present in the sample under investigation. The investigations presented here at BAMline focus on questions such as the origin, manufacturing process, and association of gold findings. The different questions are explained by a number of examples ranging from the Viking treasure from Hiddensee to the Nebra Sky Disk and finds from Egypt. The find from Bernstorf is discussed in detail. A Bayesian treatment of the authenticity is shown. T2 - Ringvorlesung Einführung in die Archäometrie CY - Berlin, Germany DA - 04.11.2022 KW - Synchrotron KW - BAMline KW - Bayesian Statistics KW - Gold KW - Röntgenfluoreszenz PY - 2022 AN - OPUS4-56252 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Automation in Computational Materials Science N2 - The talk „Automation in computational materials science“ deals with the current state of automation in the field of computational materials science. It illustrates how automation can, for example, be used to speed up the search for new ferroelectric materials and spintronic materials. Furthermore, it lists current tools for automation and challenges in the field. T2 - SALSA School 2021 CY - Online meeting DA - 16.09.2021 KW - Automation KW - High-throughput PY - 2021 AN - OPUS4-53483 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - News from the BAMline N2 - A presentation of recent measurements at the BAMline with focus on AI and ML applications T2 - Seminar: Strahlenphysikalische Anwendungen in Technik und Medizin CY - Vienna, Austria DA - 18.05.2022 KW - Synchrotron KW - BAMline KW - Bayesian Statistics KW - Gold KW - X-ray fluorescence PY - 2022 AN - OPUS4-56253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Data-Driven Chemical Understanding N2 - This talk presents my research on data-driven chemical understanding to graduate students in chemistry at the Graduate School Chemistry in Paris. T2 - Workshop : Practical applications of Machine Learning in chemistry: perspectives and pitfalls CY - Paris, France DA - 13.07.2022 KW - Chemical Understanding KW - Automation KW - Bonding Analysis PY - 2022 UR - https://gs-chem13.sciencesconf.org/ AN - OPUS4-55410 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - George, Janine T1 - Accelerated materials discovery with data analysis and machine learning N2 - Talk on my research on machine-learning and automation for students of TU Berlin T2 - TU Berlin Seminar CY - Online meeting DA - 24.01.2022 KW - Automation KW - High-throughput KW - DFT PY - 2022 AN - OPUS4-54686 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Cakir, Cafer Tufan A1 - de Oliveira Guilherme Buzanich, Ana T1 - Getting more efficient – The use of Bayesian optimization and Gaussian processes at the BAMline N2 - For more than 20 years, BAM is operating the BAMline at the synchrotron BESSY II in Berlin Adlershof. During this time, the complexity of the setup and the amount of data generated have multiplied. To increase the effectiveness and in preparation for BESSY III, algorithms from the field of machine learning are increasingly used. In this paper, several examples in the areas of beamline alignment and measurement time optimization based on Bayesian optimization (BO) with Gaussian processes (GP) are presented. BO is a method for finding the global optimum of a function using a probabilistic model represented by a GP. The advantage of this method is that it can handle high-dimensional problems, does not depend on the initial estimate, and also provides uncertainty estimates. After a short introduction to BO and GP, the first example is the automatic alignment of our double multilayer monochromator (DMM). To achieve optimal performance, up to three linear and two angular motor positions have to be optimized. To achieve this with a grid scan, at least 100^5 measurement points would be required. Assuming that all positions can be aligned independently, 100*5 points are still necessary. We show that with BO and GP less than 100 points are sufficient to achieve equal or better results. The second example is the optimization of measurement time in XRF scanning. Here we will show the advantage of the BO GP approach over point-by-point scanning. As can be seen in Fig. 1, the number of points required and thus the measurement time can be reduced by a factor of 50, while the loss in image quality is acceptable. The advantages and limitations of this approach will be discussed. T2 - European Conference on X-ray Spectrometry 2022 CY - Bruges, Belgium DA - 26.06.2022 KW - Artificial Inelligence KW - Machine Learning KW - Bayesian Statistics KW - Gaussian process KW - Neural network KW - BAMline KW - Synchrotron PY - 2022 AN - OPUS4-56251 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin A1 - Cakir, Cafer Tufan A1 - de Oliveira Guilherme Buzanich, Ana T1 - Getting more efficient – The use of Bayesian optimization and Gaussian processes at the BAMline N2 - For more than 20 years, BAM is operating the BAMline at the synchrotron BESSY II in Berlin Adlershof. During this time, the complexity of the setup and the amount of data generated have multiplied. To increase the effectiveness and in preparation for BESSY III, algorithms from the field of machine learning are increasingly used. After a short introduction to BO and GP, the first example is the automatic alignment of our double multilayer monochromator (DMM). The second example is the optimization of measurement time in XRF scanning. T2 - SNI2022 conference CY - Berlin, Germany DA - 05.09.2022 KW - Artificial Inelligence KW - Machine Learning KW - Bayesian Statistics KW - Gaussian process KW - X-ray fluorescence KW - BAMline PY - 2022 AN - OPUS4-56255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -