NUCLEAR DIFFRACTION EXPERIMENTS WITH GRAZING-INCIDENCE ANTIREFLECTIONFILMS

The energy dependent reflectivity of grazing incidence antireflection (GIAR) films containing the Mossbauer isotope Fe-57 has been measured with recoilless 14.4 keV radiation from a radioactive source. The refl ectivity is influenced by oxide layers on the surface. Assisted by Mos sbauer spectroscopy in transmission geometry and X-ray reflectivity me asurements the hyperfine interaction parameters in the layers could be determined. In a nuclear diffraction experiment with synchrotron radi ation a GIAR-film has been used as a filter, The diffracted beam was a nalysed by the (002) reflection of Yttrium Iron Garnet (YIG). The eval uation of the observed quantum beat pattern yielded the energy differe ntial reflectivity of the GIAR-film in agreement with the results from the Mossbauer measurements.