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Cesar Cusatis

Publications and source records attributed to Cesar Cusatis.

3 recordsLinked to original sources

Quantitative and qualitative studies on high-contrast X-ray radiography with an asymmetrical crystal set-up at Elettra.

An analyzer-based X-ray phase contrast imaging (ABI) system with an asymmetrical crystal set-up was mounted at Elettra's SYRMEP beamline. It was the first time that this set-up was implemented at Elettra. Advantages and disadvantages of such a set-up were exploited with quantitative and qualitative studies. For quantitative studies a simple hollow tube and strands were used as samples. Qualitative studies were developed using this technique with ox brain tissue, which has never been previously examined in this manner. Minute details were found in the ABIs and in the diffraction enhanced images. This could indicate the possibility of using these techniques with computerized tomography in the future as an auxiliary method in diagnosing brain illnesses such as Alzheimer and Creutzfeldt-Jacob disease. Propagation-based X-ray phase contrast imaging was also qualitatively exploited and compared with ABI using a Loxosceles gaucho spider as a sample.

Animals↗

Diamond thermal expansion measurement using transmitted X-ray back-diffraction.

The linear thermal expansion coefficient of diamond has been measured using forward-diffracted profiles in X-ray backscattering. This experimental technique is presented as an alternative way of measuring thermal expansion coefficients of solids in the high-resolution Bragg backscattering geometry without the intrinsic difficulty of detecting the reflected beam. The temperature dependence of the lattice parameter is obtained from the high sensitivity of the transmitted profiles to the Bragg angle variation with temperature. The large angular width of the backscattering profiles allows the application of this technique to mosaic crystals with high resolution. As an application of this technique the thermal expansion coefficient of a synthetic type-Ib diamond (110) single crystal was measured from 10 to 300 K. Extremely low values (of the order of 1 x 10(-7) +/- 5 x 10(-7)) for the linear thermal expansion coefficient in the temperature range from 30 to 90 K are in good agreement with other reported measurements.

Journal Article↗

Three exit beams from a single (hkl) X-ray diffraction plane.

An unusual case of three diffracted beams from a single incoming monochromatic X-ray beam and from the same Bragg plane is reported. Extremely asymmetric diffraction in a thin Si perfect crystal with a cleaved lateral face was experimentally studied. Two of the beams emerge grazing the front and back faces and the third beam emerges from the lateral face.

Journal Article↗