J. Synchrotron Rad.
X-ray focusing by the system of refractive lens(es) placed
inside asymmetric channel-cut crystals
Arshak H. Grigoryan, Minas K. Balyan and Albert H. Toneyan
The current work shows the calculation and study of an X-ray one-dimensionally focusing system composed of Bragg double-asymmetric-reflecting two-crystal plane parallel plates and a double-concave cylindrical parabolic lens placed in the gap between the plates. The focusing distance is calculated, intensity distribution curves are given in the focusing plane and on the focusing line, and the intensity at the focus point and the longitudinal and transverse sizes of the focus are defined.
Keywords: X-ray dynamical diffraction; X-ray refraction; X-ray optics; X-ray imaging; X-ray astronomy.
A three-block X-ray monolite resonator
Ruben T. Gabrielyan and Albert H. Toneyan
Results of an experimental and theoretical analysis are presented, concerning the six-beam (220/242/044/-224/-202) diffrac
tion of X-rays in thick perfect Ge crystals, under the conditions when a part of the diffracted beams is Bragg reflected.
Three cases are considered, when one, three, or all five diffracted beams are Bragg reflected. It is shown theoretically t
hat an enhancement of anomalous transmission for the Laue beams takes place in all these cases. Experimentally this effect
is observed in the third case on the incident beam topogram, when the two-beam Borrmann effect corresponds to Bragg refle
ction and is more weakly revealed than in the Laue case. Experimentally as well as theoretically an unusual behaviour of t
he integral intensity for the (044) beam is observed, when the number of Bragg beams varied from one to five.
Keywords: X-ray resonator; diffraction; monochromator.
On the theory of six-beam X-ray spherical-wave diffraction
V. G. Kohn and Albert H. Toneyan
Synopsis: A general formula is obtined for intensity distribution in the film behind a single crystal in the case of spherical-wave X-ray multiple diffraction.
The theory takes into account the phase shift of wavws not only inside crystal but also in the vacuum before and after the crystal along the wave path.
Phys. Stat. Sol.
Six-Beam X-Ray Diffraction in Ge Single Crystals
Petros A. Besirganyan, Ruben. Ts. Gabrielyan (a), V. G. Kohn (b),
and Albert H. Toneyan (a)