Kong Lingteng, Scott Thomas Bligh, Day John Charles Clifford, Megson-Smith David Andrew
HH Wills Physics Laboratory, Interface Analysis Centre, School of Physics, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK.
Sensors (Basel). 2024 Aug 18;24(16):5345. doi: 10.3390/s24165345.
Alpha emitters like plutonium pose severe health risks when ingested, damaging DNA and potentially causing cancer. Traditional detection methods require proximity within millimeters of the contamination source, presenting safety risks and operational inefficiencies. Long-range detection through alpha radioluminescence (RL) offers a promising alternative. However, most of the previous experiments have been carried out under controlled conditions that preclude the overwhelming effect of ambient light. This study demonstrates the successful detection of a 3 MBq alpha emitter in an open environment using a compact alpha camera. This camera incorporates a deep-cooled CCD and a low f-number lens system designed to minimize the blue shift effects of filters. Night-time imaging was achieved with a dual-filter system using a sandwich filter assembly centered at 337 nm and 343 nm for capturing alpha RL and subtracting background light, respectively. At night, the alpha source was detected from 1 m away within one minute, and the lowest detection limit can be calculated as 75 kBq. The system was also evaluated under simulated urban lighting conditions. For daytime imaging, a stack of tilted 276 nm short pass filters minimized sunlight interference, enabling the detection of the alpha source at 70 cm within 10 min under indirect sunlight. This research highlights the viability of long-range optical detection of alpha emitters for environmental monitoring in real-world settings.
像钚这样的α发射体在摄入时会带来严重的健康风险，会损害DNA并有可能引发癌症。传统的检测方法需要在距离污染源几毫米的范围内进行，存在安全风险且操作效率低下。通过α放射性发光（RL）进行远程检测提供了一种很有前景的替代方案。然而，之前的大多数实验都是在受控条件下进行的，排除了环境光的压倒性影响。本研究展示了使用紧凑型α相机在开放环境中成功检测到一个3兆贝可的α发射体。该相机集成了一个深度冷却的电荷耦合器件（CCD）和一个低f数镜头系统，旨在将滤光片的蓝移效应降至最低。夜间成像通过一个双滤光片系统实现，该系统使用一个以337纳米和343纳米为中心的三明治滤光片组件，分别用于捕捉α放射性发光和减去背景光。在夜间，一分钟内就能从1米外检测到α源，最低检测限可计算为75千贝可。该系统还在模拟城市照明条件下进行了评估。对于白天成像，一堆倾斜的276纳米短波通滤光片可将阳光干扰降至最低，在间接阳光下10分钟内就能在70厘米处检测到α源。这项研究突出了在现实环境中对α发射体进行远程光学检测以用于环境监测的可行性。
