Now the ante has been upped by two (somewhat related) groups, having combined 3D scattering pattern reconstruction with computed tomography. This gives you spatially resolved three-dimensional scattering patterns, i.e. a 3D scattering pattern for each three-dimensional voxel in space. <\/p>\n
The papers are the following:<\/p>\n
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- Marianne Liebi et al.: “Nanostructure surveys of macroscopic specimens by small-angle scattering tensor tomography”<\/a> [who was also the winner of the SAS2015 Kratky Prize<\/a>]<\/li>\n
- Florian Schaff et al.: “Six-dimensional real and reciprocal space small-angle X-ray scattering tomography<\/a>” [note that Marianne Liebi also co-authored this paper]<\/li>\n<\/ul>\n
In the same issue, a “news & views” article<\/a> can be found by Peter Fratzl, who previously also worked on 3D pattern reconstruction. This article adds some more context and a more gentle introduction to their findings.<\/p>\n
![\"The](\"http:\/\/www.lookingatnothing.com\/wp-content\/uploads\/2015\/11\/nature16056-f3-300x171.png\")
<\/a>The reconstructed bone segment of Liebi et al.. Reproduced with permission from http:\/\/dx.doi.org\/10.1038\/nature16056, Copyright \u00a9 2015, Rights Managed by Nature Publishing Group<\/figcaption><\/figure>\n ![\"nature16060-f3\"](\"http:\/\/www.lookingatnothing.com\/wp-content\/uploads\/2015\/11\/nature16060-f3-300x170.png\")
<\/a>The reconstructed tooth segment of Schaff et al.. Reproduced with permission from http:\/\/dx.doi.org\/10.1038\/nature16060, Copyright \u00a9 2015, Rights Managed by Nature Publishing Group<\/figcaption><\/figure>\n The approaches of the two groups differ slightly, with the Liebi work using spherical harmonics to describe the 3D scattering patterns, whereas Schaff did not. In my non-expert view, the use of spherical harmonics may be more resilient to reconstruction artifacts appearing in the scattering patterns, but I may be wrong about this.<\/p>\n
Both groups managed to calculate their solutions on more-or-less commercially available computer systems, making this approach more achievable by normal laboratories. Total reconstruction times were reported to be on the order of a week. Both groups used biological samples, which, as indicated in the SI of Schaff, may suffer from radiation damage in these long experiments (40h for Schaff, 36 h for Liebi). In fact, it is hard to think of samples that would not be damaged by such exposures. Bonus points to the group of Schaff for using Kieffer & co.’s pyFAI <\/a>for their initial azimuthal averaging, surely helping enormously in the reduction of the scale of the optimization problem.<\/p>\n
The obtained data looks amazing from both, and the technique is set to add much value for (not-so-nondestructive) nanostructural investigations of many hierarchical materials. With this, we may finally have a good use for those newfangled bright synchrotron sources!<\/p>\n
<\/p>\n","protected":false},"excerpt":{"rendered":"
- Florian Schaff et al.: “Six-dimensional real and reciprocal space small-angle X-ray scattering tomography<\/a>” [note that Marianne Liebi also co-authored this paper]<\/li>\n<\/ul>\n