Ge pixel array detector for high throughput X-ray spectroscopy

Abstract 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 mm 2 . 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.