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

Blog Article

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 lorenametaute.com 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 ds durga hand soap 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.