X-ray phase plate for energy-dispersive and mononchromatic experiments

Diamond crystals are excellent phase plates for the forward diffracted X-rays in the Bragg geometry. The phase-shift between the (sigma) and (pi) components of the transmitted wave varies with the incident angular offset from the center of the reflection profile and can be adjusted to any desired value. Due to the low absorption coefficient of diamond, rather thick crystals (about 1 mm thick) can be used and operated in a region where the variation of the phase-shift with the angle of incidence is not too strong. This property was exploited to obtain a high degree of circular polarization in an energy dispersive absorption spectrometer at LURE (Orsay) where the source is rather broad.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.