A new approach to deal with non-linearities in Si detector response

Abstract

A model is proposed to understand the non-linear response of Si detectors to high Z particles, which are responsible for the pulse height defect (PHD). In this phenomenon, inefficient charge collection due to charge carrier recombination is related to high energy density regions in the vicinity of the particle track, while contributions from non-ionizing atomic collisions are also estimated from the radial distribution of scattered lattice ions. These model calculations successfully reproduce published PHD data, while predicting unexpected effects in silicon-based semiconductor detection of high (relativistic) energy heavy ions. This is used to explain what seemed as intriguing features of silicon-tracker data from the Alpha Magnetic Spectrometer space project. The present model is proposed to obtain reliable ion energy measurements using silicon detectors.