Design of soft x-ray laminar-type gratings coated with supermirror-type multilayer to enhance diffraction efficiency in a region of 2-4 keV

M Koike; T Hatano; A S Pirozhkov; Y Ueno; M Terauchi

doi:10.1063/5.0148908

Design of soft x-ray laminar-type gratings coated with supermirror-type multilayer to enhance diffraction efficiency in a region of 2-4 keV

Rev Sci Instrum. 2023 Apr 1;94(4):045109. doi: 10.1063/5.0148908.

Authors

M Koike^{1

2

3}, T Hatano², A S Pirozhkov¹, Y Ueno⁴, M Terauchi²

Affiliations

¹ Kansai Photon Science Institute, Quantum Basic Sciences Directorate, National Institutes for Quantum Science and Technology, Kyoto 619-0215, Japan.
² Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan.
³ Department of Chemical Biology, Graduate School of Engineering, Osaka Metropolitan University, Sumiyoshi-ku, Osaka 558-8585, Japan.
⁴ Technology Research Laboratory, Shimadzu Corp., Seika-chou, Kyoto 619-0237, Japan.

PMID: 38081245
DOI: 10.1063/5.0148908

Abstract

Soft x-ray diffraction gratings coated with a supermirror-type multilayer were designed to enhance diffraction efficiency in the energy range of 2-4 keV by means of numerical calculations. The optimized groove depth and incidence angle are 2.05 nm and 88.65°, respectively, for the grating having a groove density of 3200 grooves/mm. Regarding the multilayer structure, the optimum number of B4C/W layers pair was 11 and the thickness of B4C was increased from bottom to top, while that of W was kept constant. The replacement of the top layer of W by either Co, Cr, or Ni was an effective means of obtaining uniform diffraction efficiency. In the region of 2-4 keV, the calculated diffraction efficiency of the designed gratings was up to ∼5.3%, on average, and almost eight times larger than that of ∼0.7% of an Au coated grating.