Testing of a `hard' X-ray interferometer for experimental investigations.

A `hard' X-ray LLL interferometer is tested for experimental investigations. The interferometer has both a base and a `ceiling', which are rigidly connected through columns. As a result, the interferometer does not have uncontrollable preliminary moiré. The intensity distribution is uniform in the interfering beams. It is shown that the interferometer is very sensitive to minor mechanical stresses. As a result, the interferometer must be freely placed on the goniometer head. Constant-thickness fringes are obtained using a wedge with a vertically placed apex. The volumes available for specimen placement are limited due to the existence of the ceiling. These difficulties can be overcome. The hard interferometer can be used for object and deformation investigations.