X-ray zoom lens allows for energy scans in X-ray microscopy.

E Kornemann,T Zhou,T U Schülli,A Last,A Opolka,O Márkus,J Mohr

doi:10.1364/oe.27.000185

E Kornemann, T Zhou + Show 5 more

Open Access

https://doi.org/10.1364/oe.27.000185

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Abstract

We introduce a new design and development of a compound refractive X-ray zoom lens for energy scans in X-ray microscopy. Energy scans are, in principle, equivalent to radial scans in the reciprocal space for X-ray diffraction. Thanks to the absence of sample or detector motions, energy scans are better suited for microscopy, which requires high stability. In addition, close to the absorption edge of an element, energy scans can yield chemical information when coupled with resonant effects in full field diffraction X-ray microscopy (FFDXM) or X-ray absorption near edge structure (XANES) microscopy. Here, we demonstrate the concept by using a customized compound refractive X-ray zoom lens for 11 keV near the Ge Kα-edge. The working distance and magnification were kept constant during the energy scans by adapting the lens composition on switchable zoom lens fingers. This alleviates the need to reposition the lens while changing the energy and makes quantitative analysis more convenient for FFDXM. The fabricated zoom lens was characterized and proven suitable for the proposed measurement.

Highlights

Plenty new experimental ideas can become possible if one overcomes the chromatic nature of compound refractive lenses (CRLs) with the development of adaptive optics
The X-ray zoom lens, which consists of SU-8 lenses fabricated by deep X-ray lithography, has been tested and characterized at ID01, European Synchrotron Radiation Facility (ESRF)
There is no sample, objective or detector motion involved during energy scans, the images are kept sharp in microscopy mode and the magnification constant in shadow projection mode

Summary

Introduction

Plenty new experimental ideas can become possible if one overcomes the chromatic nature of compound refractive lenses (CRLs) with the development of adaptive optics. Note that while the X-ray zoom lens can be optimized to achieve a constant effective focal length fzl (i.e., the distance from the back principle plane H’ to the back focal point F’ [Fig. 2]), in the microscopy setup, the goal is to achieve a constant magnification factor M.

Fabrication of customized X-ray zoom lens

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Findings

Conclusion