A Position-Sensitive Microstrip Detector using Amorphous Selenium Photoconductor

A novel amorphous selenium multilayer detector was previously proposed for single photon emission computed tomography with a high spatial resolution and a cost-effective manufacturing process. However, the complexity of reading out multi-layer detector arrays was an impediment. In this research, we examine using a microstrip detector readout scheme with amorphous selenium photoconductor for the first time. Microstrip readout schemes can simplify detector readout implementation, because the signal is read simultaneously at both ends of a resistive electrode. The charge induced on the readout electrode undergoes charge division along the electrode and is proportional to the physical location of absorbed photons, enabling position sensitivity. A 1 mm collimated blue LED, with a wavelength of 470 nm, is employed to illuminate the electrode that has a resistivity of 205 kΩ. Although the measured currents from the two ends of the electrode show a slightly non-linear behavior, position sensitive photon detection was confirmed.