Mathematical Models of External Gamma Radiation and Congruence of Measurements

Abstract

Gamma rays emitted from walls of buildings contribute significantly to the external radiation exposure of the population. Although the activities of building materials are measurable before a room is built, the dose rates in the room, or in different organs of a human body standing in the room can be measured only after the room has been built. In this paper the most important calculational methods are reviewed that can be used to predict the dose rates once the activities of the building materials are known. The discussion starts from those relatively simple methods that lead to correct results for free-in-air doses and ends up at a short description of Monte Carlo calculations whose use enables phantom organ doses and spectra of photons to be determined. Comparisons of measured and calculated results are presented and discussed.