Gamma-ray imaging detectors based on silicon drift detectors arrays coupled to a single scintillator

Arrays of Silicon Drift Detectors (SDDs) coupled to a single scintillator, according to the Anger Camera scheme, can be successfully employed in gamma-ray imaging. The low value of output capacitance of a SDD allows to reach a lower electronics noise with respect to conventional silicon photodiodes used in scintillation detection. A small prototype of gamma camera with sub-millimeter resolution has been realized by using a monolithic array of small SDDs (5 mm2 each unit) with on-chip JFET. For the realization of gamma cameras of larger areas based on single units assembled in array, SDDs of 30 mm2 of area with external JFET have been also experimented.