Monte Carlo simulation was performed on a Poshwich detector for measuring radioactivity of β particles in radioactive aerosol.The detector model consists of plastic scintillator and BGO crystal
with aluminum foil in the front to stop α particles and considerations to prevent the γ-rays from affecting the β-ray detection.Code Geant4 was used to calculate the energy deposition in the scintillators and their attenuation coefficient
The size and the structure of the detector ware determined based on the simulation.