Department of Physics, Carleton University, Ottawa, Ontario, Canada; Canadian Hazards Information Service, Natural Resources Canada, Ottawa, Ontario, Canada; Ionizing Radiation Standards, Metrology Research Centre, National Research Council, Canada; Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta, Canada.
Department of Physics, Carleton University, Ottawa, Ontario, Canada; Ionizing Radiation Standards, Metrology Research Centre, National Research Council, Canada.
J Environ Radioact. 2024 Sep;278:107491. doi: 10.1016/j.jenvrad.2024.107491. Epub 2024 Jul 14.
An advanced spatial-unfolding technique capable of reconstructing the activity distribution within an exclusion zone from Compton gamma imager measurements taken outside of it is introduced. Although the method is generally applicable to extended sources, we demonstrate it here on a calibrated Cs-137 point source through Monte Carlo simulation studies as well as with measurements made using a Silicon Compton Telescope for Safety and Security (SCoTSS) gamma imager. For synthetic data the method accurately reconstructs the total activity contained within the mapped zone of interest, even when the size of the basis elements used to reconstruct the activity distribution is larger than the source itself. For experimental data, the method reliably located the source but underestimated its activity by up to 17%. This is accurate enough for real-world security applications. The underestimation is likely due to effects not yet included in the simulated response of the detector. The method has widespread applicability in the radiological/nuclear safety and security field, particularly for scenarios in which a threat material or contaminated area lies within a no-entry or no-fly zone.
介绍了一种先进的空间展开技术，能够根据在禁区外测量的康普顿伽马成像仪数据，重建禁区内的活动分布。虽然该方法通常适用于扩展源，但我们通过蒙特卡罗模拟研究以及使用安全和保障用硅康普顿望远镜伽马成像仪进行的测量，在此将其应用于校准的 Cs-137 点源。对于合成数据，该方法可以准确地重建映射感兴趣区域内的总活动，即使用于重建活动分布的基础元素的大小大于源本身。对于实验数据，该方法可靠地定位了源，但活动估计值低估了多达 17%。这对于现实世界中的安全应用来说已经足够准确了。这种低估可能是由于探测器的模拟响应中尚未包含的影响。该方法在放射性/核安全和保障领域具有广泛的适用性，特别是在威胁物质或污染区域位于禁入或禁飞区的情况下。
