The x-ray interferometer is not a joke. In about 1974, Gerd Materlik built one
for his thesis and inserted it in front of my beamline at the DESY synchrotron.
The beam splitters and "mirrors" were all carved out of a single block of
perfect single crystal silicon. He inserted a wedge of plastic
Hi Murpholino and Eddie,
I looked up what we found in our study of the decay of thaumatin crystals at 3
energies (Acta Cryst. (2015). D71, 772-778).
Figure 2 shows the unit cell parameter a vs. dose for 5 crystals (all from the
same batch). One crystal shows a fairly linear expansion of +0.06% p
