Ge pixel array detector for high throughput x-ray absorption spectroscopy: Performance and unconventional applications

For high throughput and energy-resolution florescence X-ray absorption spectroscopy (XAS), a novel Ge pixel array detector (PAD) with 100 segments has been developed. Two sets of PAD having different thickness values, i.e., 10 mm (#1) and 7.5mm (#2), were constructed and installed at Spring-8 (BL10XU) and Photon Factory (BL13B). Using a monolithic approach, a nearly perfect packing fraction (>88%) and commission rate (99%) were achieved, resulting in a significant improvement over a previous Ge multi-element detector. In the present PAD design, each segment is square-shaped having an active area of 22mm(2). The average energy resolution at 5.9 keV was 220 eV (6 mu s shaping time) and 240 eV (0.5 mu s) in a high throughput mode. High efficiency X-ray detection over a wide energy range (5-60 keV) was confirmed. The present electronics-limited throughput maximum is 100 kcps per channel or 10 MHz in total. We will describe unconventional applications in fluorescence XAS demonstrating the capability of PAD. The recent in-situ XAS study under laser light required a small amount of specimen (less than 10(-3) g).