TY - CONF A1 - Radtke, Martin T1 - From Egypt to Hiddensee – Analysis of Gold with Synchrotron Radiation V 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 - 01.11.2024 KW - Gold KW - Synchrotron KW - XRF KW - BAMline KW - Bayes PY - 2024 AN - OPUS4-61699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Getting more efficient – The use of Bayesian optimization and Gaussian processes at the BAMline N2 - The BAMline, a beamline for material science research at BESSY II, has been operated by the Bundesanstalt für Materialforschung und -prüfung for over two decades. In the last few years, Bayesian optimization (BO) with Gaussian processes (GP) has been introduced as a transformative method in this setting. This contribution highlights the integration and impact of BO and GP in refining BAMline operations. We will explore the impact of integrating Bayesian methods, especially when combined with Gaussian processes, on the operational efficiency of the BAMline. Our discussion commences with an overview of the fundamental concepts of active learning and optimization. This is followed by an in-depth analysis of specific case studies, drawing on our direct experience with these innovative methods. For this our focus is on three key applications: Alignment of Optical Elements (DCM and DMM): The implementation of Bayesian optimization using Gaussian processes has revolutionized the alignment process for the Double Crystal Monochromator (DCM) and the Double Multilayer Monochromator (DMM). This approach greatly reduced manual effort and enhanced the efficiency and effectiveness of the alignment procedure. Optimal Spot Selection for Spatial Mapping in XRF Studies: In X-ray fluorescence (XRF) experiments, determining the most informative sampling spots is crucial. The introduction of BO, informed by GP, has significantly improved the selection process, especially in large or heterogeneous samples. This methodology ensures maximum information gain, optimizing the balance between comprehensive mapping and resource management. Selection of Optimal Energies for XANES Measurements in GEXANES Geometry: In the specific context of X-ray Absorption Near Edge Structure (XANES) studies using Grazing Exit (GEXANES) geometry, the Bayesian approach with Gaussian processes is now utilized to identify the most effective energy settings. This results in detailed spectral data acquired in a much shorter time. We also address challenges and limitations encountered during implementation. Additionally, the versatility of this approach in addressing a range of different research questions will be demonstrated. T2 - Machine Learning Conference for X-Ray and Neutron-Based Experiments CY - Garching bei München, Germany DA - 08.04.2024 KW - BAMline KW - Synchrotron KW - XRF KW - Bayes PY - 2024 AN - OPUS4-61703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radtke, Martin T1 - Insights into materials with hard x-rays: capabilities of the bamline N2 - This contribution provides an overview of the BAMline synchrotron radiation beamline, which specializes in hard X-ray spectroscopy techniques for materials research. The BAMline offers X-ray absorption spectroscopy (XAS), x-ray fluorescence spectroscopy (XRF), and tomography to study materials' electronic structure, chemical composition, and structure. Key capabilities include standard and dispersive XAS for electronic structure, micro-XRF for elemental mapping, coded aperture imaging, and depth-resolved grazing exit XAS. The BAMline enables in situ characterization during materials synthesis and functions for energy, catalysis, corrosion, biology, and cultural heritage applications. Ongoing developments like the implementation of machine learning techniques for experiment optimization and data analysis will be discussed. For instance, Bayesian optimization is being used to improve beamline alignment and scanning. An outlook to the future, where the BAMline will continue pioneering dynamic and multi-scale characterization, aided by advanced data science methods, to provide unique insights into materials research, will be given. T2 - μ-XRF at Elettra 2.0: challenges and opportunities CY - Trieste, Italy DA - 11.09.2023 KW - Synchrotron KW - XRF KW - XANES KW - Bayes PY - 2023 AN - OPUS4-58607 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -