Evaluation of efficiency for in situ gamma spectrometer based upon cerium-doped lanthanum bromide detector dedicated for environmental radiation monitoring

摘要

Nuclear power plants that are planned to be constructed in various countries, including Poland, require to setup an environmental radiation monitoring system. Localization of the installation has to be preceded by the studies determining the level of natural background radiation. Presently the in situ gamma spectrometry is widely used for monitoring the natural as well as artificial radionuclides. An analysis and evaluation of parameters of the spectrometric system equipped with scintillation detector made of cerium-doped lanthanum bromide crystal are both the subject of the paper. The main question of the application of any gamma spectrometry system for the radiation monitoring purpose is how its efficiency looks like. Based on the numerical characteristics of the detector the absolute full energy peak efficiency was calculated. The three dimensions characteristics of gamma ray registration efficiency as the function of its energy and considered contaminated area diameter has been also performed. The study of numerical modeling based on MCNP code was performed by the ISOCS/LabSOCS software tool.