Monte-Carlo Calculation of the γ-Ray Dose Distribution Inside a Wall of a Building and in Air

The Monte Carlo method is used to calculate the coefficients used to convert from the measured (using retrospective luminescence dosimetry) γ-ray dose inside the wall of a building to the dose in air. The γ-ray dose distributions in the wall and in air were calculated simultaneously. The calculations were performed for a γ-ray sources located in air, on the surface of soil, and in a 0–5 cm thick top layer of soil. The γ-ray spectra in air and inside a wall are calculated and it is shown that the spectrum depends strongly on the type of source – the average energy of the spectrum is 0.25 MeV for a source located on a soil surface, 0.39 MeV for a source located inside the soil, and 0.53 MeV for a source located in air.