7-element analyzer for emission spectroscopy in IDD


To improve collection efficiency in x-ray emission spectroscopy (XES) experiments, we have designed and commissioned a seven-element analyzer XES spectrometer at 16 ID-D of HPCAT. The spectrometer has seven 4-inch spherical bent analyzers arranged in a hexagonal pattern to make it compact and accommodate the opening of the most used 2-inch symmetric diamond anvil cells. Fluorescence from the sample is spectrally analyzed and reflected to a Pilatus 100K position sensitive detector by these analyzers. An emission spectrum is obtained by rotating the analyzer Δϑ, tracked by the corresponding 2Δϑ rotation of the detector. Bending radius of all analyzers is one-meter, with seven analyzers, the spectrometer covers a solid angle of ~56msr. This new spectrometer collects a similar solid angle compared to miniXES and polycapillary lens spectrometer and still keeps an energy resolution of ~1eV. We currently have six different silicon analyzer indexes to cover varieties of emission lines (4.5-22keV). With the new seven-analyzer XES spectrometer, the collection efficiency can be improved ~4-30 times depending on the measured emission lines. A comparison between the XES spectra of Fe Kβ1,3 of ferropericlase at 90 GPa measured with one-analyzer and seven-analyzer XES spectrometers shows an efficient increase of 22 times. (Key personnel: Yuming Xiao, Paul Chow)