Mechanical Stretching of a Perfect Single Crystal: a Routeway to a D-Spacing Tunable X-ray Monochromator

The feasibility of using traction forces to produce mechanical stretching/shrinkage in a perfect Si 400 single crystal is explored theoretically (by finite element analysis and dynamical theory of X-ray diffraction) and experimentally in order to use it as an angular static interplanar-distance (d-spacing) tunable monochromator, in the Bragg case. It is shown that, with traction forces of ∼100 N and an appropriate pre-load, it is possible to scan, with a linear response and reproducibility of ∼5%, a 30 eV bandwidth, which corresponds to a d-spacing scan of 7 × 10−3 Å.