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http://dx.doi.org/10.7742/jksr.2018.12.1.101

Analysis of Reflectivity for Interfacial Roughness of Depth-Graded W/Si Multilayer Mirror  

Chon, Kwon Su (Department of Radiological Science, Daegu Catholic University)
Publication Information
Journal of the Korean Society of Radiology / v.12, no.1, 2018 , pp. 101-106 More about this Journal
Abstract
Multilayer mirrors have widely been used for monochromatization of X-ray with high reflection efficiency. The reflected X-ray energy or wavelength is determined by the d-spacing of a multilayer mirror and the incidence angle. The reflectivity critically depends on the number of bilayers and surface roughness on each interface. The multilayer mirror has a structure of alternative deposition of high and low Z-elements on the substrate. Each interface should be considered in the calculation of reflectivity. In this paper, we examine the degradation of reflectivity by the inter-diffusion combined with surface roughness on each interface for a W/Si multilayer mirror. In the depth-graded W/Si multilayer mirror, the FWHMs for angle and energy were larger than them of the uniform multilayer mirror. Inter-diffusion considerable gave rise to the degradation of reflectivity. To obtain measured reflectivity closed to the expected reflectivity, the inter-diffusion on W-Si and Si-W interfaces should be considered.
Keywords
X-ray Optics; Multilayer Mirror; Reflectivity; Inter-diffusion;
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