Noise analysis of low noise, high count rate, PIN diode X-ray detectors

In a noise analysis for a planned p-i-n diode X-ray detector array, we particularly included process dependent 1/f and 1/f² terms, and explored the effect of input transistor parameters and peaking time t_p on energy resolution ΔE. We find that, for t_p<1 μs and careful processing, both 1/f and 1/f² terms are negligible and the usual approaches for minimum noise (reduce capacitances and shorten gate lengths) remain valid. We present a concrete example to see just how good performance may be. Thus a 0.1 pF detector, at 300 K with 0.5 μm gate length transistors, produces a ΔE of 52 eV for a t_p of 180 ns