Open AccessThe theoretical analysis of the hard X-ray block-structure supermirror
Author(s) -
Youwei Yao,
H. Kunieda,
Zhanshan Wang
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.008638
Subject(s) - optics , block (permutation group theory) , function (biology) , physics , materials science , geometry , mathematics , evolutionary biology , biology
We present an analytical study to provide guide lines to design a block structure hard X-ray supermirror. The block structure supermirror is a kind of layered structure consisting of several "blocks" of multilayer of different d-spacing to obtain broad energy bandwidth response. This structure has been widely applied in X-ray telescopes because it is easy to fabricate. To examine the propagation of X-rays in a supermirror structure, further simplified approximation of Kozhevnikov's theory has been developed. The supermirror structure is described by a structure function. The spectral function of the structure, which is the Laplace transformation of the structure function, turns out to be proportional to the reflectivity profile against X-ray energy. By analyzing the expression of the spectral function, we found the reflectivity of the supermirror could be smooth due to the box-car shaped spectral function if the d-spacing and layer number of each block is arranged with appropriate constraints.