Characterization of Large-Area Silicon Drift Detectors at High Count Rates

Abstract

Silicon Drift Detectors (SDD) are being developed for analytical x-ray spectrometry having large active area, high-energy resolution and capability of operating at high counting rates. The development derives from the charged coupled device (CCD) for light-signal imaging, utilizing the extremely low capacitance of the detector and readout electronics and subsequent developments of silicon drift detectors for high-energy physics applications and more recently, x-ray spectroscopy applications. The now well-known advantage of the drift detector design is that, unlike traditional planar detectors, it allows for relatively large active area while still maintaining a very low anode capacitance (60 fF). This low value of detector capacitance results in a lowering of the series-noise component and hence the overall inherent electronic noise. Additionally, the reduction of the series noise leads to faster optimal shaping time, and as a consequence this provides for extremely high count rates.