journal menu
research papers
The instrumental window of a double crystal spectrometer in the dispersive (1, +1) position has been determined experimentally with a Mössbauer source and compared with theoretical predictions. The experiment was done at a wavelength of 0.86 Å* with the 14.4 keV γ ray that follows the 57Co→57Fe decay. The crystals employed were quartz (10
1), silicon (111), germanium (111), and calcite (211) (104), where the indices refer to the structural cells. The theoretical expression for the double-crystal window was calculated as the convolution of the appropriate single-crystal monochromatic profiles predicted by the Darwin–Prins dynamical theory of X-ray diffraction. The agreement between theory and experiment was good and clearly shows the necessity for crystal asymmetry corrections to precision wavelength determinations in certain cases.
1), silicon (111), germanium (111), and calcite (211) (104), where the indices refer to the structural cells. The theoretical expression for the double-crystal window was calculated as the convolution of the appropriate single-crystal monochromatic profiles predicted by the Darwin–Prins dynamical theory of X-ray diffraction. The agreement between theory and experiment was good and clearly shows the necessity for crystal asymmetry corrections to precision wavelength determinations in certain cases.
