Speakers
Description
The distance between crystallographic planes is of the same order as the X-ray wavelength. For this reason, crystals act as diffraction gratings for X-ray [1]. This interaction is referred as diffraction of real photons. On the other hand, Parametric X-ray Radiation (PXR) has been described as the diffraction of the charged particle Coulomb field in the crystal. This mechanism is referred as diffraction of pseudo, virtual or equivalent photons [2].
This experimental work presents the measurements of signals produced during the interaction of both 7 MeV electrons and X-rays with tungsten powders. The measurements correspond to the diffraction of virtual and real photons respectively. Tungsten powders were chosen because in the energy region between 2 and 7 keV the diffracted peaks from five crystallographic planes can be analysed without the influence of background peaks. The characteristics of both diffraction processes are analysed and compared. Parameters such diffraction peak yield, peak FWHM and peak to background ratio are discussed.
The work was supported by scholarship of the President of the Russian Federation for young scientists and graduate students SP-765.2019.2 and by project PIJ-16-03 of the Escuela Politécnica Nacional.
References
[1] R. James. The Optical Principles of the Diffraction of X-rays. (1948).
[2] X. Artru, P. Rullhusen. Nucl. Inst. Meth. B 145 (1998) 1-7.