<title>Solution of x-ray diffraction inverse problems in optics</title>

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

“…The pendulum fringe method [12] makes it possible to determine F hkl and f a without measuring the energy dispersion parameters. According to bidirectional approximation for dynamic scattering of X-rays, there are two coherent waves propagating towards each of reciprocal lattice nodes 0 and m, with the interference period [3][4][5] equal to…”

“…From the standpoint of Xray diffraction, the above crystals are traditionally referred to typical representatives of ideally mosaic crystals [3][4][5][6][7]. However, advances in the technology of single crystal growth and X-ray topography methods have changed the conventional point of view.…”

“…the methods of integral intensities of X-ray dispersion, deviation from the Bragg's law, and total external reflection. However, the corresponding measurement errors have been high enough (7-10% [3][4][5]). 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.…”

“…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].…”

“…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.…”