Journal of Technology & Science
May 30, 2010
ELECTROMAGNETIC RESEARCH;
Study results from Yerevan State University broaden understanding of
electromagnetic research
According to recent research published in the Journal of Synchrotron
Radiation, “An X-ray one-dimensionally focusing system, a
refracting-diffracting lens (RDL), 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 is described. It is shown that the focal length of the RDL
is equal to the focal distance of the separate lens multiplied by the
square of the asymmetry factor.”
“One can obtain RDLs with different focal lengths for certain
applications. Using the point-source function of dynamic diffraction,
as well as the Green function in a vacuum with parabolic
approximation, an expression for the double-diffracted beam amplitude
for an arbitrary incident wave is presented. Focusing of the plane
incident wave and imaging of a point source are studied. The cases of
non-absorptive and absorptive lenses are discussed. The intensity
distribution in the focusing plane and on the focusing line, and its
dependence on wavelength, deviation from the Bragg angle and
magnification is studied. Geometrical optical considerations are also
given. RDLs can be applied to focus radiation from both laboratory and
synchrotron X-ray sources, for X-ray imaging of objects, and for
obtaining high-intensity beams,” wrote A.H. Grigoryan and colleagues,
Yerevan State University.
The researchers concluded: “RDLs can also be applied in X-ray astronomy.”
Grigoryan and colleagues published their study in the Journal of
Synchrotron Radiation (X-ray focusing by the system of refractive
lens(Es) placed inside asymmetric channel-cut crystals. Journal of
Synchrotron Radiation, 2010;17(Part 3):332-347).
For additional information, contact M.K. Balyan, Yerevan State
University, Solid State Physics Research Laboratory, Dept. of Solid
State Physics, Faculty Physics, Yerevan, Armenia.
The publisher’s contact information for the Journal of Synchrotron
Radiation is: Wiley-Blackwell Publishing, Inc., Commerce Place, 350
Main St., Malden 02148, MA, USA.
From: A. Papazian