High efficiency and low absorption Fresnel compound zone plates for hard X-ray focusing

TL;DR

This paper reports the fabrication and testing of high-efficiency, low-absorption Fresnel compound zone plates on silicon for 8 keV X-ray focusing, achieving small focused spots and high diffraction efficiency.

Contribution

It introduces novel compound zone plates with multiple diffraction orders fabricated on silicon, demonstrating improved focusing performance for hard X-ray applications.

Findings

Focused spot size of 0.5 micrometers

Diffraction efficiency of 39% in the first order

Successful testing at synchrotron sources

Abstract

Circular and linear zone plates have been fabricated on the surface of silicon crystals for the energy of 8 keV by electron beam lithography and deep ion plasma etching methods. Various variants of compound zone plates with first, second, third diffraction orders have been made. The zone relief height is about 10 mkm, the outermost zone width of the zone plate is 0.4 mkm. The experimental testing of the zone plates has been conducted on SPring-8 and ESRF synchrotron radiation sources. A focused spot size and diffraction efficiency measured by knife-edge scanning are accordingly 0.5 mkm and 39% for the first order circular zone plate.