TY - GEN A1 - Hashemi, Seyedreza A1 - Zscherpel, Uwe T1 - Measurement of Focal Spots of X-ray Tubes Using a CT Reconstruction Approach on Edge Images of Large Holes and Comparison to Pinhole Imaging N2 - The first Non-destructive testing (NDT) method which evolved in the industrial age was radiographic testing (RT). Among all NDT methods, RT is no exception, so there are still many issues for optimizations even today. One of them is the measurement of the focal spot of X-ray tubes. The size of the focal spot is critical for imaging, because it determines the spatial resolution in the X-ray image. The classical way to evaluate focal spots of X-ray tubes is by pinhole imaging using a camera obscura. But this method has a natural lower limit, which is defined by the diameter of the pinhole used (today min. 10 µm). Therefore, focal spot sizes lower than 50 µm diameter cannot be imaged and measured correctly. An alternative approach, which permits this, was investigated here using the edge unsharpness of holes much larger than the focal spot size. The results of both methods were compared using 3 different X-ray tubes. KW - Reconstruction method KW - Radiographic testing (RT) using X-rays KW - Focal spot measurement KW - Edge unsharpness KW - X-ray tubes KW - Pinhole imaging KW - Computed Tomography (CT) KW - Focal Spot (FS) PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-608646 DO - https://doi.org/10.58286/29556 SN - 2941-4989 SP - 1 EP - 9 PB - NDT.net CY - Berlin, Germany AN - OPUS4-60864 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Bernd R. A1 - Lange, Axel A1 - Harwardt, Marco A1 - Hentschel, Manfred P. A1 - Illerhaus, Bernhard A1 - Goebbels, Jürgen T1 - Synchrotron Refraction CT and Synchrotron Bragg Magnification CT for NDE T2 - International Symposium on Digital industrial Radiology and Computed Tomography (DIR 2007) CY - Lyon, France DA - 2007-06-25 KW - X-ray Refraction KW - Diffraction Enhanced Imaging (DEI) KW - Bragg Magnification KW - Synchrotron Radiation KW - Computed Tomography (CT) KW - Metal Matrix Composites (MMC) KW - Lightweight Materials KW - Aerospace PY - 2007 IS - CD-ROM SP - 1 EP - 8 CY - Lyon, France AN - OPUS4-16366 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -