Radiation source position measurement system using radiation spectroscopy detectors with maximum likelihood position estimation

초록

A system for measuring the position of a radiation source using a radiation spectroscopy detector and maximum likelihood position estimation (MLPE) was designed. Three radiation spectroscopy detectors were used to detect gamma-rays generated from radiation sources at each position, and a look-up table was prepared by converting them into ratios. The look-up table was created more precisely through interpolation. The accuracy of measuring the position of the radiation source was evaluated by applying the prepared look-up table and the ratio of gamma-rays generated from each radiation source position to MLPE. This approach was then compared with the method of measuring the position by calculating the number of radiation detected in the radiation spectroscopy developed in the previous study. For this comparison, Geant4 Application of Tomographic Emission (GATE), which enables simulation of interaction between radiation and materials, was used. When MLPE was used, the overall average error rate was 1.71 +/- 5.16%. When the position was measured through calculation, the overall average error rate was found to be 5.82 +/- 7.67%. When measuring the position of the radiation source, it was found that the error rate increases as the distance on the Y-axis increases. However, it was confirmed that the corresponding error rate increased significantly when using the calculation method, and showed a relatively small increase rate when MLPE was used. Using a system that applies MLPE to the radiation spectroscopy detector, the method of measuring the position of the radiation source will be enhanced further.

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