Experimental and Simulated Spectral Gamma-Ray Response of a NaI(Tl) Scintillation Detector used in Airborne Gamma-Ray Spectrometry
OPEN ACCESS
Loading...
Author / Producer
Date
2022
Publication Type
Journal Article
ETH Bibliography
yes
Citations
Altmetric
OPEN ACCESS
Data
Rights / License
Abstract
The objective of this work is to simulate the spectral gamma-ray response of NaI(Tl) scintillation detectors for airborne gamma-ray spectrometry (AGRS) using the state-of-the-art multi-purpose Monte Carlo code FLUKA. The study is based on a commercial airborne gamma-ray spectrometry detector system with four individual NaI(Tl) scintillation crystals and a total volume of 16.8 L.
To validate the developed model, radiation measurements were conducted using 57Co, 60Co, 88Y, 109Cd, 133Ba, 137Cs and 152Eu calibration point sources with known activities and source-detector geometries under laboratory conditions. In addition, empirical calibration and resolution functions were derived from these measurements combined with additional radiation measurements adopting natural uranium, thorium and potassium volume sources.
The simulation results show superior accuracy and precision compared to previous AGRS simulation models with a median relative spectral error < 10 % for most of the radiation sources. Moreover, the implementation of a lower level discriminator model and detailed modelling of the laboratory result in a significant improvement in model accuracy for spectral energies < 100 keV compared to previous studies. Yet thorough statistical analysis incorporating statistical and systematic uncertainty estimates revealed statistically significant deviations between the simulated and measured spectra in the spectral region around the Compton edge, which could be attributed to the scintillator non-proportionality.
These findings imply that the linear energy deposition model applied in this and previously developed AGRS simulation models should be revised and considered to be replaced by more accurate non-proportional models.
Permanent link
Publication status
published
External links
Editor
Book title
Journal / series
Volume
57
Pages / Article No.
89 - 107
Publisher
Copernicus
Event
Edition / version
Methods
Software
Geographic location
Date collected
Date created
Subject
Organisational unit
03864 - Kirch, Klaus / Kirch, Klaus
Notes
Funding
Related publications and datasets
Is supplemented by: