Moir  images simulation of strains in x-ray interferometry

Abstract

The mechanisms of the x-ray Moiré images formation was investigated for the strain fields created by point forces in the analyser plate of a three-crystal LLL-interferometer. The size of the area of the effective interaction between two series of Moiré fringes—the Moiré fringes caused by a stationary phase shift of the interfering waves and strain Moiré fringes—depends on the crystal thickness and on the force. The largest transformations of Moiré patterns are observed in the case of a force acting on the crystal-analyser entrance (with respect to the incident x-ray beam) surface.

Optical parameters of CaF2, LiF, NaCl and KCl single crystals in the X-ray spectral range

“…As a result, the accuracy for those parameters is greatly reduced (down to 7-10% [3][4][5]). On the contrary, this study employs the pendulum fringe and the X-ray interferometry methods [8][9][10][11][12] related to interference pattern geometry, rather than measuring the energy parameters themselves, and so they enable n and ∆f' to be measured with much higher accuracy (~ 0.1-0.5%).…”

“…In this work, the methods of pendulum fringes and X-ray interferometry [8][9][10][11][12] have been used in order to measure structural (F hkl ) and atomic (f a ) dispersion amplitudes, as well as dispersion corrections ( f ′ ∆ ) and single decrements (α) of refractive indices. Our studies have been performed using single crystals of CaF 2 , LiF, NaCl, and KCl grown from a melt along [100] direction.…”

“…It is a high structural perfection of our CaF 2 , LiF, NaCl and KCl single crystals that has allowed us to apply, for the first time, interferometry-precision research methods. So, the pendulum fringe method enables measuring the F hkl , f a and f ′ ∆ values with the errors of 0.1-1.0%, while the X-ray interferometry yields the f ′ ∆ and α values for any amorphous, polycrystalline or single-crystalline material, being characterised with the errors as low as 0.1-0.5% [8][9][10][11][12].…”

Multiple-wave diffraction in x-ray interferometers

“…Analysis of diffraction geometry shows that even in the case of three-wave diffraction and using the simplest types of interferometers it is possible to combine in one device several schemes of typical two-wave interferometers and multi-beam interferometry [8][9][10][11][12][13][14][15][16] .…”

Interferometric study of deformation fields arising at laser treatment of Si surface

“…The energy of packing defects in Si, deformations around the dislocation clusters, defects of interface and stress relaxation in epitaxial systems Si-Si, Ge-Si, GaP-Si, as well as the effect of ultrasonic deformations on moiré patterns were determined in [10][11][12][13][14] . Formation of moire patterns of deformation fields arising under the effect of point forces on the interferometric analyzer are detailed in 15,16 .…”