SEMICONDUCTOR DRIFT DETECTORS FOR HIGH-RESOLUTION X-RAY SPECTROSCOPY

The properties and performances of silicon drift detectors for X-ray spectroscopy applications are presented. The peculiar characteristic of these detectors is the transport along the detector of the charge generated by the radiation toward a small collecting anode, whose capacitance can be as low as 60 fF, irrespective of the sensitive area. This feature is the key of the extremely high resolution available from this class of devices. Recent experimental results showing an energy resolution at room temperature down to 110 electrons rms with a detector of 1 cm2 active area and external electronics are reported. Detectors with different topologies especially designed to improve the resolution in the X-ray energy range are presented. The status of the activity on direct integration of the electronics in the detector itself is also reported.