Attempt to estimate the background pulse height spectrum of the CeBr3 scintillation spectrometer due to terrestrial gamma ray components: Application in environmental radiation monitoring

This article describes an attempt to estimate the background (BG) pulse height spectrum (PHS) of the CeBr3 scintillation spectrometer due to terrestrial gamma ray components. In radiological emergencies, there are some cases which the prior measurement of the background components can't be made. By subtracting the BG components from the measured gross PHS, timely and accurate information about the artificial radionuclides involved in the emergencies would be effectively drawn to protect the member of the public and first responders. A Monte Carlo calculation was conducted to simulate the PHS by gamma rays from natural radionuclides uniformly distributed in the ground. The calculated PHS were verified to be consistent with measured PHS. Derived dose equivalent rate from the calculated PHS were compared with reference value and found to be in good agreement with each other. The study revealed that applying the calculated PHS to the in-situ gamma ray spectrometry components hardly affected the determination of surface deposition density on soil for radioactive cesium. •The authors demonstrate the simulation of the pulse height spectrum (PHS) obtained by the CeBr3 scintillation spectrometer used for emergency radiation monitoring. During radiological emergencies, timely and reliable radiological information such as dose equivalent rate, H*(10) and surface contamination densities on soil in affected areas should be measured.•The synthesized PHS were in quite good agreement with measured PHS. The inherent component due to self-contamination of the CeBr3 spectrometer is found to be appropriately accounted for estimation.•The MDAs of surface contamination density on soil for 134Cs and 137Cs were also derived from the synthesized PHS obtained from the MC calculation. The MDAs for each radioactive Cs estimated from measured and simulated PHS were in good agreement with each other.