福岛核电站附近污染物的首次现场真实Gamma-Ray成像光谱
First On-Site True Gamma-Ray Imaging-Spectroscopy of Contamination near Fukushima Plant
摘要：
我们研制了一台电子跟踪康普顿照相机（ETCC），它通过将每个γ射线的方向重建为一个点，提供了一个定义良好的点扩散函数（PSF），并首次实现了MeV γ射线亮度和光谱的同时测量。在这里，我们介绍了我们的现场试点伽玛成像光谱与ETCC在三个污染的位置在日本福岛第一核电站附近的2014年的结果。利用遥感观测得到的亮度（或发射率）分布被明确地转换成剂量分布。我们确认，剂量分布是一致的，通过传统的映射测量与剂量计物理放置在每个网格点。此外，它的成像光谱学，由康普顿边缘自由光谱增强，揭示了复杂的放射性特征，在定量的方式在每个单独的目标点在背景占主导地位的环境。值得注意的是，我们成功地确定了残留铯污染的“微热点”，即使在已经净化的区域。这些结果表明，ETCC的性能完全符合几何光学的预测，在现场辐射测量中显示了其多功能性，并揭示了在许多领域的应用潜力，包括核工业，医学领域和天文学。
英文摘要：
We have developed an Electron Tracking Compton Camera (ETCC), which provides a well-defined Point Spread Function (PSF) by reconstructing a direction of each gamma as a point and realizes simultaneous measurement of brightness and spectrum of MeV gamma-rays for the first time. Here, we present the results of our on-site pilot gamma-imaging-spectroscopy with ETCC at three contaminated locations in the vicinity of the Fukushima Daiichi Nuclear Power Plants in Japan in 2014. The obtained distribution of brightness (or emissivity) with remote-sensing observations is unambiguously converted into the dose distribution. We confirm that the dose distribution is consistent with the one taken by conventional mapping measurements with a dosimeter physically placed at each grid point. Furthermore, its imaging spectroscopy, boosted by Compton-edge-free spectra, reveals complex radioactive features in a quantitative manner around each individual target point in the background-dominated environment. Notably, we successfully identify a "micro hot spot" of residual caesium contamination even in an already decontaminated area. These results show that the ETCC performs exactly as the geometrical optics predicts, demonstrates its versatility in the field radiation measurement, and reveals potentials for application in many fields, including the nuclear industry, medical field, and astronomy.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
