Ge pixel array detector for high throughput X-ray spectroscopy

For high throughput/energy-resolution fluorescence X-ray detection in X-ray absorption spectroscopy (XAS), a novel Ge pixel array detector (PAD) with 100 segments has been developed. Using a monolithic approach, a high packing density (88%) with nearly perfect commission rate (99%) were achieved, resulting in a dramatic improvement in packing density compared to the close-packed multi-element detector (57%). Two types of PAD was built with the pixel thickness of 7.5 and 10 mm. Each segment has an active area of 22 mm2. The average energy resolution at 5.9 keV was ca. 220 eV (6 μs shaping time) and 240 eV (0.5 μs shaping time). High efficiency in X-ray detection in a wide energy range (5–60 keV) was confirmed. The present data acquisition system, CAMAC-based hybrid electronics, is capable of independent energy-analysis and recording all channels with a maximum 100 kcps per channel or 10 MHz in total. Elimination of elastic and inelastic scattering improved the systematic error in XAS, as demonstrated by an XAS application to a photo-induced phase transition.