Modelling of Pulse Height Spectra of Gamma Detectors for Simplified Models of a Radioactive Cloud

Abstract

The paper considers the issues of determining the pulse height spectra of gamma detector from a radioactive cloud. This task is of interest from the point of view of possible improvement of existing systems for monitoring the radiation situation around nuclear power plants and nuclear industry enterprises due to the wider use of gamma-spectrometric equipment. Modeling of pulse height spectra will allow conducting research on the capabilities of monitoring system posts for detecting radionuclides in the radioactive cloud. A general approach to modeling pulse height spectra using division of the radioactive cloud into elementary gamma sources is developed. The pulse height spectra of scintillator NaI ∅63×63 mm are calculated for simplified models of the radioactive cloud in the form of a linear gamma source and a semi-infinite space. The obtained data can be used for rapid estimates of pulse height spectra, while the formulated approach to spectra modeling also allows for more time-consuming calculations for an arbitraryshaped radioactive cloud with an arbitrary radionuclide composition.