Soil Moisture and Air Humidity Dependence of the Above-Ground Cosmic-Ray Neutron Intensity
Soil Moisture and Air Humidity Dependence of the Above-Ground Cosmic-Ray Neutron Intensity
复制标题
土壤湿度和空气湿度对地面宇宙线中子强度的依赖性
DOI：
10.3389/frwa.2020.544847
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发表时间：
2021
影响因子：
6.3
通讯作者：
U. Schmidt
中科院分区：
文献类型：
--
作者：
M. Köhli;J. Weimar;M. Schrön;R. Baatz;U. Schmidt
通过蒙特卡罗模拟对中子在空气和土壤中的传输进行了研究，从而在精确解释测量结果方面取得了重大进展;它们特别提高了对宇宙射线中子足迹的理解。到目前为止，土壤湿度到可探测中子计数率的转换主要依赖于Desilets和Zreda在2010年提出的方程。虽然一般来说，双曲线表达式可以从理论上推导出来，但由于两个原因，它们的经验参数化需要修改。首先，严格的数学处理表明，四个参数的值是模糊的，因为它们的值不是独立的。我们发现了一个三参数方程的参数值是明确的，这是等价的，在任何其他方面的四参数方程。其次，高分辨率的蒙特-卡罗模拟揭示了一个系统的偏差的计数率土壤水分的关系，特别是在极端干燥的条件下，以及非常潮湿的条件。这暗示了对强度的较小贡献被传统方法遗忘或没有得到充分处理。通过广泛的蒙特-卡罗模拟活动调查地面上的中子通量揭示了对该信号的不同贡献的更详细的理解，特别是针对空气湿度校正。软件包MCNP和URANOS被用来推导出一个函数，能够描述各自的依赖关系，包括不同的氢池和检测器特定的响应函数的效果。新的关系已经在两个典型的测量站点进行了测试，其卓越的性能允许在未来更全面的数据质量的一个充满希望的前景。
Investigations of neutron transport through air and soil by Monte Carlo simulations led to major advancements toward a precise interpretation of measurements; they particularly improved the understanding of the cosmic-ray neutron footprint. Up to now, the conversion of soil moisture to a detectable neutron count rate has relied mainly on the equation presented by Desilets and Zreda in 2010. While in general a hyperbolic expression can be derived from theoretical considerations, their empiric parameterization needs to be revised for two reasons. Firstly, a rigorous mathematical treatment reveals that the values of the four parameters are ambiguous because their values are not independent. We found a three-parameter equation with unambiguous values of the parameters that is equivalent in any other respect to the four-parameter equation. Secondly, high-resolution Monte-Carlo simulations revealed a systematic deviation of the count rate to soil moisture relation especially for extremely dry conditions as well as very humid conditions. That is a hint that a smaller contribution to the intensity was forgotten or not adequately treated by the conventional approach. Investigating the above-ground neutron flux through a broadly based Monte-Carlo simulation campaign revealed a more detailed understanding of different contributions to this signal, especially targeting air humidity corrections. The packages MCNP and URANOS were used to derive a function able to describe the respective dependencies, including the effect of different hydrogen pools and the detector-specific response function. The new relationship has been tested at two exemplary measurement sites, and its remarkable performance allows for a promising prospect of more comprehensive data quality in the future.
影响因子：
5.4
作者：
Bogena, H. R.;Huisman, J. A.;Vereecken, H.
通讯作者：
Vereecken, H.
影响因子：
5.4
作者：
Baatz, R.;Bogena, H. R.;Vereecken, H.
通讯作者：
Vereecken, H.