TY - JOUR A1 - Nowak, S.H. A1 - Bjeoumikhov, A. A1 - Von Borany, J. A1 - Buchriegler, J. A1 - Munnik, F. A1 - Petric, M. A1 - Radtke, Martin A1 - Renno, A.D. A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Wedell, R. T1 - Sub-pixel resolution with a color X-ray camera N2 - The color X-ray camera SLcam® is a full-field, single photon detector providing scanning-free, energy and spatially resolved X-ray imaging. Spatial resolution is achieved with the use of polycapillary optics guiding X-ray photons from small regions on a sample to distinct energy dispersive pixels on a charged-coupled device detector. Applying sub-pixel resolution, signals from individual capillary channels can be distinguished. Therefore, the SLcam® spatial resolution, which is normally limited to the pixel size of the charge-coupled device, can be improved to the size of individual polycapillary channels. In this work a new approach to a sub-pixel resolution algorithm comprising photon events also from the pixel centers is proposed. The details of the employed numerical method and several sub-pixel resolution examples are presented and discussed. KW - Color X-ray camera KW - Sub pixel analysis PY - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-334948 SN - 0267-9477 SN - 1364-5544 SP - 1890 EP - 1897 PB - Royal Society of Chemistry CY - London AN - OPUS4-33494 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Nowak, S. H. A1 - Petric, M. A1 - Buchriegler, J. A1 - Bjeoumikhov, A. A1 - Bjeoumikhova, Z. A1 - von Borany, J. A1 - Munnik, F. A1 - Radtke, Martin A1 - Renno, A. D. A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Tilgner, J. A1 - Wedell, R. T1 - Road to micron resolution with a color X-ray camera – polycapillary optics characterization N2 - In a color X-ray camera spatial resolution is achieved by means of a polycapillary optic conducting X-ray photons from small regions on a sample to distinct energy dispersive pixels on a CCD matrix. At present, the resolution limit of color X-ray camera systems can go down to several microns and is mainly restricted by Pixel dimensions. The recent development of an efficient subpixel resolution algorithm allows a release from pixel size, limiting the resolution only to the quality of theoptics. In this work polycapillary properties that influence the spatial resolution are systematized and assessed both theoretically and experimentally. It is demonstrated that with the current technological Level reaching one micron resolution is challenging, but possible. KW - Color X-ray camera KW - Polycapillary optics PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-404404 UR - https://arxiv.org/abs/1705.08939 SN - 2331-8422 SP - 1 EP - 11 PB - Cornell University CY - Ithaca, NY AN - OPUS4-40440 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nowak, S.H. A1 - Bjeoumikhov, A. A1 - Von Borany, J. A1 - Buchriegler, J. A1 - Munnik, F. A1 - Petric, M. A1 - Renno, A.D. A1 - Radtke, Martin A1 - Reinholz, Uwe A1 - Scharf, O. A1 - Strüder, L. A1 - Wedell, R. A1 - Ziegenrücker, R. T1 - Examples of XRF and PIXE imaging with few microns resolution using SLcam® a color X-ray camera N2 - We present results of recent development of the color X-ray camera, type SLcam®, allowing detection of X-ray images with few microns resolution. Such spectral resolution is achieved with the use of high-quality polycapillary optics combined with sub-pixel resolution. Imaging of Siemens star resolution test chart reveals that the resolution limit of SLcam® can go down to nearly 5µm. Several real sample examples of measurements carried out at the laboratory, synchrotron, and particle-induced X-ray emission beamlines are shown. This is the first time SLcam® is used as particle-induced X-ray emission detector. KW - X-ray KW - Color X-ray camera KW - CXC KW - Synchrotron radiation KW - BESSY KW - BAMline PY - 2015 U6 - https://doi.org/10.1002/xrs.2590 SN - 0049-8246 VL - 44 IS - 3 SP - 135 EP - 140 PB - Wiley & Sons, Ltd. CY - Chichester AN - OPUS4-33170 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 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 U6 - 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 -