Contrast investigations of surface acoustic waves by stroboscopic topography. 2

When imaging a surface acoustic wave by stroboscopic X-ray topography a contrast contribution exists which can be related to the deviation of X-ray beams in the deformation field of the acoustic wave. With narrow entrance slits this contribution can be separated from the surface reflected waves. Using a beam path theory of Bonse the beam trajectories inside the crystal and the intensity profiles at the surface are calculated. It is also demonstrated that this contrast which has two nearly equal peaks within the acoustic period turns to the orientation contrast with one peak per period when increasing the distance between sample and film. (author)