Multithreshold Pattern Recognition Algorithm for Charge Sharing Compensation in Hybrid Pixel Detectors

Abstract

Single photon counting pixel detectors offer an excellent position resolution and allow X-ray photons selection according to their energy. However, for small pixel sizes a charge sharing effect can significantly distort a measured energy spectrum of incoming photons. An on-chip implementation of a sophisticated algorithm using inter-pixel communication is required to overcome this limitation. In this paper we analyze different algorithms implemented in integrated circuits to eliminate the effect of charge sharing and we propose a new architecture to solve this problem. The proposed algorithm is simulated extensively in the wide energy range of X-ray photons (used e.g. in medical imaging), taking into account realistic detector parameters, noise of readout electronics and the problem of mismatch in a pixel matrix.