Specht Aaron J, Weisskopf Marc G, Nie Linda Huiling
Purdue University, School of Health and Human Sciences, West Lafayette, IN, United States of America. Harvard University, T.H. Chan School of Public Health, Boston, MA, United States of America.
Physiol Meas. 2017 Mar;38(3):575-585. doi: 10.1088/1361-6579/aa5efe. Epub 2017 Feb 7.
K-shell x-ray fluorescence (KXRF) techniques have been used to identify health effects resulting from exposure to metals for decades, but the equipment is bulky and requires significant maintenance and licensing procedures. A portable x-ray fluorescence (XRF) device was developed to overcome these disadvantages, but introduced a measurement dependency on soft tissue thickness. With recent advances to detector technology, an XRF device utilizing the advantages of both systems should be feasible.
In this study, we used Monte Carlo simulations to test the feasibility of an XRF device with a high-energy x-ray tube and detector operable at room temperature.
We first validated the use of Monte Carlo N-particle transport code (MCNP) for x-ray tube simulations, and found good agreement between experimental and simulated results. Then, we optimized x-ray tube settings and found the detection limit of the high-energy x-ray tube based XRF device for bone lead measurements to be 6.91 µg g bone mineral using a cadmium zinc telluride detector.
In conclusion, this study validated the use of MCNP in simulations of x-ray tube physics and XRF applications, and demonstrated the feasibility of a high-energy x-ray tube based XRF for metal exposure assessment.
几十年来，K 壳层 X 射线荧光（KXRF）技术一直被用于识别金属暴露对健康产生的影响，但该设备体积庞大，需要大量维护且有繁琐的许可程序。一种便携式 X 射线荧光（XRF）设备被开发出来以克服这些缺点，但引入了对软组织厚度的测量依赖性。随着探测器技术的最新进展，一种兼具两种系统优点的 XRF 设备应该是可行的。
在本研究中，我们使用蒙特卡罗模拟来测试一种配备高能 X 射线管且探测器可在室温下运行的 XRF 设备的可行性。
我们首先验证了蒙特卡罗 N 粒子输运代码（MCNP）用于 X 射线管模拟的有效性，并发现实验结果与模拟结果吻合良好。然后，我们优化了 X 射线管设置，发现使用碲化镉锌探测器的基于高能 X 射线管的 XRF 设备对骨铅测量的检测限为 6.91 µg/g 骨矿物质。
总之，本研究验证了 MCNP 在 X 射线管物理模拟和 XRF 应用中的有效性，并证明了基于高能 X 射线管的 XRF 在金属暴露评估中的可行性。
