Sliced linear zone plates for hard X-ray radiation

Linear zone plates for hard ($E >$ 10 keV) X rays are considered. The technology of the plates includes cutting magnetron-sputtered W$_5$Si$_3$/Si multilayer coatings. The results of numerical computation suggest that this pair of materials provides a high efficiency in the first and second diffraction orders. It is found experimentally that good multilayer structures consisting of several hundreds of layers can be synthesized on silicon and glass substrates. It is shown that they can be cut by ion etching the multilayer coating through a mask.