Geant4 Model for the Stopping Power of Low Energy Negatively Charged Hadrons

An original model is presented for the simulation of the energy loss of negatively charged hadrons. It calculates the stopping power by regarding the target atoms as an ensemble of quantum harmonic oscillators; this approach allows to account for charge dependent effects in the stopping power, which are relevant at energies below a few MeV. The resulting antiproton stopping powers for different elements are shown to be in satisfactory agreement with experimental data. The model described in this paper is implemented in the Low Energy Electromagnetic package of the Geant4 Toolkit; it represents a significant improvement for the accurate simulation of low energy negative hadrons with respect to previously available models.