TY  - THES
AB  - The pnCCD is a special type of a charge coupled devices developed for spectroscopy and imaging of X-rays. Different from other CCD concepts, pnCCD is a four-dimensional detector, in which the data volume is spanned over two spatial, one energy, and one time coordinates, with fast frame rates up to 1000 images/sec, high energy resolution, low electronic noise and an excellent quantum efficiency at soft X-ray energy range. Considering these parameters, the pnCCD has been used for single crystal structure analysis in the soft X-ray energy range (5-35 keV) so far. In this thesis we demonstrate single grain analysis of a polycrystalline sample by means of an energy-dispersive Laue diffraction (EDLD) using white X-ray radiation in the hard energy range (35-130 keV). In particular we investigate the deformation behavior of individual grains under tensile loading. In addition to many other advantages of the pnCCD in material science applications, the use of hard X-ray radiation penetrates deeply inside the samples and examine a largest possible number of grains within the specimen. However, the detection of the high energetic photons by silicon-based detectors is limited by the detector quantum efficiency. This drawback can be overcome by combining a columnar scintillator with a pixelated silicon-based pnCCD detector. In this thesis we report on the characterization of a low noise, fully depleted pnCCD coupled to a columnar structure CsI(Tl) scintillator in hard X-ray range. The performance of the detection system in the energy range between 40 keV to 130 keV was tested by means of a Laue type X-ray diffraction experiment. Realized at the EDDI beamline of the BESSY II synchrotron we recorded Laue pattern of a set of several GaAs single crystals irradiated by white synchrotron radiation. The first application of this new system in crystallography is demonstrated by a crystal structure analysis of a tetragonal SrLaAlO4 crystal in which the lattice parameters and the cell orientation has been determined with an accuracy better than 0.7%. In addition, the structure factors moduli have been determined from the intensities of the Laue spots with a standard deviation of less than 2.5%.
AU  - Shokr, Mohammad
DA  - 2019
KW  - CCD-Sensor
KW  - Festkörperphysik
KW  - pnCCD
KW  - Materialwissenschaften
KW  - Solid state physics
KW  - X-ray
KW  - Material science
LA  - eng
PY  - 2019
TI  - From pnCCD to pnCCD + CsI(Tl) scintillator: characterizations and applications
UR  - https://nbn-resolving.org/urn:nbn:de:hbz:467-14814
Y2  - 2024-12-26T22:26:44
ER  -