A Geant4 based study of the response of surface barrier detector for alpha-particles

This study presents a Geant4 based comprehensive characterization of a silicon Surface Barrier Detector (SBD) for charged particle spectroscopy, with a specific focus on alpha particle detection. This work investigates the fundamental properties governing detector response, including the Bragg curve, Range and absolute detection efficiency. The Geant4 simulated Bragg curves have been found in good agreement with the corresponding TCAD-SRIM based data. For the 1–10 MeV domain of energy values of α-Particles, the Range in Silicon is found to exhibit a quadratic behavior. The Geant4 simulated absolute efficiency of SBD in parallel, coaxial source–detector configuration has been found in agreement with the corresponding experimental data. The Geant4 simulated absolute efficiency data has also been found in good agreement with the corresponding numerical/theoretical values for various values of source dimensions and for various values of source-to-detector axial distances. The Geant4 based absolute efficiency values show a gradual decrease with increasing radial displacement for fixed value of axial distance.