Connection of segmented intensity data measured with a multiple-detector system for powder diffractometry

A Fourier method to connect segmented intensity data measured with a multiple-detector system (MDS) for powder diffractometry has been developed. Differences in sensitivity, slight shifts in peak positions and asymmetric instrumental broadening for different detectors are simultaneously adjusted by a Fourier-based deconvolution/convolution method. The Fourier transform of the adjustment function is evaluated as the ratio of the Fourier transforms of the intensity data sets in the overlapped region measured with the adjacent detectors. Even and odd polynomial functions with maximum order of 10 are separately fitted to the real and imaginary parts of the experimentally evaluated Fourier-transformed adjustment by a least-squares method applying an appropriate weighting for the Fourier-transformed data. The complex of the optimized polynomials is used to adjust the data measured with a detector in order to connect them with the data measured with an adjacent detector. The method is applied to connect the powder diffraction data of ZnO powder measured with the MDS on beamline BL4B₂ at the Photon Factory in Tsukuba. Slight differences in line width, asymmetry and sharpness detected in the observed diffraction peak profiles measured with the different detectors have successfully been removed by the Fourier-based adjustment procedures.