Calculating teletherapy room shielding using albedos: a method of predicting exposure rates at, and shielding required in, maze-protected doors

Abstract

The exposure rate at the maze-protected door of a therapy room can be computed easily using the concept of gamma -ray albedo and a digital computer, if the exposure rate in the useful beam at some distance, the amount of leakage radiation and the room dimensions are known. The results of computer calculation show attenuation factors of 150-1000 for typical therapy rooms with maze walls and for gamma -ray energies of 200 keV to 1.25 MeV.