Multiple-pulse readout of linear Silicon Drift Detectors for fast imaging applications

We discuss the imaging properties of Controlled-Drift Detectors at high photon occupancy that is when the analog waveform at the anode to be readout contains several pulses that may even be partially overlapping. This condition is encountered when the detector is operated in integrate-readout mode at high count rates like in synchrotron experiments. The imaging information, i.e. the incident photon distribution along the column, is still preserved in the waveform and it can be reconstructed by means of a suitable multiple-pulse signal processing. We evaluated multiple-pulse processing based on the weighted least square algorithm in the most relevant operating conditions to assess the achievable resolution of pulse amplitude and position. This analysis allows definition of achievable performances and limitations of Controlled Drift Detectors in high-rate single-photon spectroscopic imaging of X-rays.