Monolithic arrays of silicon drift detectors for medical imaging applications and related CMOS readout electronics

Monolithic arrays of Silicon Drift Detectors (SDDs) have been recently proposed to be used with scintillators for high-position-resolution γ-ray imaging applications. Thanks to the low electronics noise due to the small value of the output capacitance, the SDD offers better performances with respect to conventional photodiodes of the same geometry. We show the results achieved with a small monolithic array of SDDs, each one with a front-end JFET integrated at its center, used as photodetector in a first prototype of Anger Camera. An intrinsic resolution better than 200 μm has been achieved with this prototype. Moreover, we describe a new monolithic array of SDDs composed of 77 single hexagonal units, each one with an active area of 8.7 mm2, for a total active area of the device of 6.7 cm2. Finally, the basic principles and the first results of the CMOS readout chip specifically designed for the readout of the signals from SDDs arrays are presented.