Fig. 12.

Adorym reconstruction of a tomographic X-ray fluorescence and ptychography dataset of a frozen hydrated alga cell Chlamydomonas reinhardtii acquired using 5.5 keV X rays [77]. The phosphorus $K$ fluorescence projection (a) at $0^{\circ }$ through the 3D volume highlights polyphosphate bodies, which are also seen at somewhat lower resolution in the ${90}^{\circ }$ projection through the reconstruction due to the limited tomographic tilt range of ${\mathrm{-68}}^{\circ }$ to ${\mathrm{+56}}^{\circ }$. As in a previously-reported reconstruction of this dataset [77], this phosphorus reconstruction used refinement of the tomographic tilt angles, leading to angular corrections about all three axes as shown in (c). These refined angles were then employed in a subsequent ptychotomography reconstruction, yielding a 3D volume rendered in (d). Sub-images in (e) show optical sections from the reconstructed volume cut at indicated $z$-positions after it is rotated about the $y$-axis by ${30}^{\circ }$. In (f), the power spectra of the reconstructions in the $x$-, $y$-, and $z$-direction are shown. For each case, two lines with the same color are fitted respectively using datapoints with spatial frequency in the range of 0.008–0.31$f_{\text{Ny}}$ and 0.47–1.0$f_{\text{Ny}}$. As the latter fits the noise plateau, the intersection between both lines (marked by dotted vertical lines) provides a measure of spatial resolution.