Methods of angular scanning in imaging and topography
In an imaging experiment using the topography or phase contrast techniques, generally, the result is a single image, which represents the internal structure of the object. However, identification of the features of the observed structure is a challenge. In these methods, an important parameter is the scattering angle, and methods of using its variation are being actively developed [1,2], making possible to obtain a scattering curve for each local region of a sample. The report discusses the results of applying the methods of the angular scanning experiments in the synchrotron topography and analyzer based imaging. The curved silicon single crystals are currently used at the big accelerators (LHC etc) as deflectors for the extraction and collimation of the proton beams. Using the method of topography with angular scanning at synchrotron radiation such a deflector was studied, the curvature of its elements was measured and its performance at the passage of the proton beam was understood. A wide range of objects was studied with the help of analyzer based imaging with angular scanning. Several samples of opals of natural and artificial origin were investigated. Images of all the samples were obtained in a wide angular range from the peak of crystal reflection to the distant tail at about 102 of FWHM. The majority of the samples displayed the inhomogeneous structure with regions that changed their brightness, relative to adjacent regions, during the rotation of the analyzer crystal. Another kind of a sample was an ancient parchment, where the features of its structure on tens micrometers scale can provide a valuable information of the parchment manufacturing technology.
- A. A. Kaloyan, E. S. Kovalenko, and K. M. Podurets, Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques, 2014, Vol. 8, No. 3, pp. 429–432.
- Lübbert D., Baumbach T., Härtwig J., Boller E., Pernot E. Nucl. Instrum. Meth. 2000 B160 521