High-speed high-resolution signal processing for multicell silicon drift detectors

A data acquisition system is presented for X-ray spectroscopic and imaging applications. It has the capability to process the signals of up to 120 silicon drift detector channels in parallel. The signal processing comprises a 12-bit digitization at 1 MSps per detector channel, an optical readout at 2.488 Gbit/s, and an online histogramming with a counting depth of 32 bits per energy class and channel. The user gains full system control and VMEbus-based data access by an additional bidirectional optical link and a commercial VME controller, respectively. The system's performance tests show that the integral nonlinearity and the rms noise do not exceed /spl plusmn/0.4 LSB and 0.58 LSB, respectively. The mean rms noise over all channels amounts to 0.55 LSB. The modular system's setup assures an upgradability to 1860 detector channels in steps of 120.