Simulation of the thermoelastic behavior of an LLL x-ray interferometer

In order to achieve the strictest tolerances required in the manufacturing of an x-ray interferometer of the triple Laue type (LLL) to be used in the accurate determination of the silicon lattice parameter, a new shape of the analyzer crystal is considered. The simulation of its behavior proves that , if specified elastic and thermal load upper limits are satisfied, the lat tice plane deformations are compatible with a measurement uncertainty of a few parts in 10(9). (C) 2000 American Institute of Physics. [S0034-6748(00) 02004-9].