Model of the SCT detectors and electronics for the ATLAS simulation using Geant4

This note presents a model that describes how the SCT detectors and electronics respond to ionization deposited by particles. The model is intended for the digitization of the SCT hits in the future ATLAS simulation using Geant4 and written in C++. The current implementation is limited to barrel modules. A comparison with beam test data is presented. By tuning the model to the data we find that the calibration scale is accurate within 5% for two barrel modules that were both tested in beam and simulated. The tuned model is able to reproduce the SCT beam test data with sufficient accuracy.