Estimation of Argon-41 concentrations in the vicinity of a high-energy medical accelerator

摘要

This study presents the estimation of Ar-41 concentrations using the neutron activation method. The distribution of thermal neutron flux in a 15 MV medical accelerator (linac) treatment room was determined and contoured by measuring the radioactivities of indium foils irradiated by thermal neutrons. The Ar-41 concentrations were calculated based on the spatial distribution of thermal neutrons. The evolution of Ar-41 concentration with time in the treatment room was predicted and the corresponding radiation dose associated with Ar-41 was derived and shown to be insignificant for both patients and workers, being below the regulatory level. Indium foil activation method showed high detection sensitivity for estimating the low-level Ar-41 in the vicinity of medical accelerators, yielding a minimum detectable concentration of less than 10 Bq m(-3). (C) 2007 Elsevier Ltd. All rights reserved.