Application of a Capacitive Charge-Sharing Circuit for Reducing the Number of Readout Channels of Multichannel Semiconductor Detectors with p–n Junctions

The article considers an electronic circuit that, in some cases, makes it possible to significantly reduce the number of readout channels in a silicon coordinate detector based on a matrix of p–i–n structures (strip- or pad-type) without a loss in the coordinate measurement accuracy. The electronic circuit is a chain of external capacitors that connect the structures of the detector. When one of the structures is hit, a signal propagates along the chain of capacitors of the capacitive divider to the nearest readout channels and it is possible to determine the original number of the hit structure by the change in the signal value. The proposed circuit was mathematically simulated for typical parameters of the detector and readout electronics. The mathematical model allowed us to optimize the circuit parameters depending on the parameters of the detector and readout electronics. The simulation results are confirmed by experimental measurements on several prototypes of the device. It is shown that, in certain application cases, when a detector signal is high enough, e.g., when nuclei with Z > 6 are registered, one can achieve, by using standard low-noise operational amplifiers, the accurate recovery of the number of the hit structure in the chain consisting of at least 30 structures by reading only two extreme structures.