Mobile radiation detection systems are used widely in remediation and nuclear security. However, their detection efficiency and thus their minimum detectable activity is not completely understood. It is recognized that the detector's velocity will affect its detection efficiency. At lower speeds, detection efficiency will be higher than a detector moving at higher speeds. The relationship describing how speed and efficiency are related was only recently quantified using a modified four-parameter logistic function (M4PL). The current research verifies the M4PL function in a controlled laboratory setting using a 5.08 cm × 5.08 cm sodium iodide detector at speeds between 20-120 cm s-1. As expected, the M4PL function indicates a detection system's highest efficiency at low speeds and its lowest efficiency at higher speed. In between is a transition region of decreasing detector efficiency. This decrease is gradual within initial speeds but quickly steepens and then approaches a minimum at higher detector speeds. This general shape was observed in the experimental data and validated the M4PL function as a predictive tool. To conclude this research and to demonstrate the function's usefulness, a relationship between speed and minimum detectable activity (MDA) was developed. Using this function and the methods described in this research, planners can now optimize surveys by controlling velocity to maintain MDA. It is also possible to use this technique to accelerate surveys while having the ability to predict the reduction in MDA. This foundational relationship between detector speed and detection efficiency has the potential to improve detector performance in various applications for both the academic and operational fields.

中文翻译：

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验证将最小可检测活动与检测器速度相关联的方法。

移动辐射探测系统广泛用于修复和核安全。然而，它们的检测效率以及它们的最小可检测活性尚未完全了解。人们认识到探测器的速度会影响其探测效率。在较低速度下，检测效率将高于以较高速度移动的检测器。描述速度和效率之间关系的关系最近才使用改进的四参数逻辑函数 (M4PL) 进行量化。目前的研究在受控实验室环境中使用 5.08 cm × 5.08 cm 碘化钠探测器以 20-120 cm s-1 的速度验证了 M4PL 功能。正如预期的那样，M4PL 函数表明检测系统在低速时效率最高，在高速时效率最低。其间是检测器效率降低的过渡区域。这种下降在初始速度内是逐渐的，但很快就会变陡，然后在较高的探测器速度下接近最小值。在实验数据中观察到了这种一般形状，并验证了 M4PL 函数作为预测工具的效果。为了总结这项研究并证明该功能的实用性，建立了速度和最小可检测活性 (MDA) 之间的关系。使用此功能和本研究中描述的方法，规划人员现在可以通过控制速度来维持 MDA 来优化调查。还可以使用该技术来加速调查，同时能够预测 MDA 的减少。探测器速度和探测效率之间的这种基本关系有可能提高探测器在学术和操作领域的各种应用中的性能。