Hellfeld Daniel, Bandstra Mark S, Vavrek Jayson R, Gunter Donald L, Curtis Joseph C, Salathe Marco, Pavlovsky Ryan, Negut Victor, Barton Paul J, Cates Joshua W, Quiter Brian J, Cooper Reynold J, Vetter Kai, Joshi Tenzing H Y
Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
Gunter Physics, Inc., Lisle, IL, 60532, USA.
Sci Rep. 2021 Oct 15;11(1):20515. doi: 10.1038/s41598-021-99588-z.
The ability to map and estimate the activity of radiological source distributions in unknown three-dimensional environments has applications in the prevention and response to radiological accidents or threats as well as the enforcement and verification of international nuclear non-proliferation agreements. Such a capability requires well-characterized detector response functions, accurate time-dependent detector position and orientation data, a digitized representation of the surrounding 3D environment, and appropriate image reconstruction and uncertainty quantification methods. We have previously demonstrated 3D mapping of gamma-ray emitters with free-moving detector systems on a relative intensity scale using a technique called Scene Data Fusion (SDF). Here we characterize the detector response of a multi-element gamma-ray imaging system using experimentally benchmarked Monte Carlo simulations and perform 3D mapping on an absolute intensity scale. We present experimental reconstruction results from hand-carried and airborne measurements with point-like and distributed sources in known configurations, demonstrating quantitative SDF in complex 3D environments.
在未知三维环境中绘制和估计放射源分布活动的能力，在预防和应对放射性事故或威胁以及执行和核查国际核不扩散协议方面具有应用价值。这种能力需要具备特征明确的探测器响应函数、精确的随时间变化的探测器位置和方向数据、周围三维环境的数字化表示，以及合适的图像重建和不确定性量化方法。我们之前已经使用一种称为场景数据融合（SDF）的技术，在相对强度尺度上用自由移动探测器系统演示了伽马射线发射体的三维映射。在此，我们使用经过实验基准测试的蒙特卡罗模拟来表征多元素伽马射线成像系统的探测器响应，并在绝对强度尺度上进行三维映射。我们展示了在已知配置下，使用点状和分布式源进行手持和机载测量的实验重建结果，证明了在复杂三维环境中的定量SDF。
