Effects of analyser deformation in scanning x-ray interferometry

摘要

Measurement of the (220) Bragg-plane spacing of Si using combined x-ray and optical interferometry with an uncertainty lower than 10-8 requires the study of influence factors not considered in the past. In this paper the Bragg-plane spacing definition itself is re-examined and the influence of a constant strain gradient is studied by means of Takagi's equations. Their analytical and numerical solutions indicate that, contrary to our previous assumption, the period of the travelling fringes is affected by the Si atom spacing at the analyser entrance surface.