Focusing Polycapillary Optics and Their Applications

<table>The spot size is enlarged from the channel diameter <svg height="6.4625001" id="M40" style="vertical-align:-0.12375pt" version="1.1" viewbox="0 0 6.6374998 6.4625001" width="6.6374998" xmlns="http://www.w3.org/2000/svg">
<g transform="matrix(1.25,0,0,-1.25,0,6.4625)">
<g transform="translate(72,-66.83)">
<text transform="matrix(1,0,0,-1,-71.95,67.01)">
<tspan style="font-size: 11.21px; " x="0" y="0">𝑐</tspan>
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</g>
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</svg> because of the local divergence which arises from reflections at angles up to the critical angle.</table>

X-Ray Optics and Instrumentation

fig18

Figure 18

Figure 18: Focusing Polycapillary Optics and Their Applications 