Electron scattering in solid state detectors: Geant 4 simulations Original Research Article

All plasmas in the magnetosphere and interplanetary space contain non-thermal populations. Critical information on their acceleration mechanisms is provided by the slope of their energy spectra. The measurement of how energetic (non-thermal) electron spectra evolve in time provides fundamental information on how their acceleration processes develop. In an effort to characterize the response of current energetic particle instruments to energetic electrons we have taken advantage of the Geometry and Tracking toolkit (GEANT4) to provide the framework for an instrument model and a simulation environment. The results of these simulations match very well with data collected during various instrument calibration tests and give us confidence that GEANT4 handles electron interactions with matter in a reasonable fashion. The results of a specific Monte Carlo simulation (the response of the ACE/EPAM instrument to near-relativistic solar electron events) will be discussed. Given the usefulness of these simulations the GEANT4 toolkit has become an integral part of current and future energetic particle instrument development efforts.