Diffractive X-Ray Telescopes

<table>The critical Fresnel number, <svg height="12.9125" id="M78" style="vertical-align:-2.92279pt" version="1.1" viewbox="0 0 17.575001 12.9125" width="17.575001" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,12.9125)">
<g transform="translate(72,-61.67)">
<text transform="matrix(1,0,0,-1,-71.95,64.63)">
<tspan style="font-size: 11.21px; " x="0" y="0">𝑁</tspan>
</text>
<text transform="matrix(1,0,0,-1,-62.41,61.83)">
<tspan style="font-size: 7.85px; " x="0" y="0">0</tspan>
</text>
</g>
</g>
</svg>, for some example materials. Numbers, colors, and materials as in Figure <a href="../fig2/">2</a>.</table>

X-Ray Optics and Instrumentation

Diffractive X-Ray Telescopes

Figure 3