Microstrip electrode readout noise for load-dominated long shaping-time systems

In cases such as that of the proposed International Linear Collider (ILC), for which the beam-delivery and detector-occupancy characteristics permit a long shaping-time readout of the microstrip sensors, it is possible to envision long ( ∼ 1 meter) daisy-chained ‘ladders’ of fine-pitch sensors read out by a single front-end amplifier. In this study, a long shaping-time ( ∼ 2 μ sec ) front-end amplifier has been used to measure readout noise as a function of detector load. Comparing measured noise to that expected from lumped and distributed models of the load network, it is seen that network effects significantly mitigate the amount of readout noise contributed by the detector load. Further reduction in noise is demonstrated for the case that the sensor load is read out from its center rather than its end.