A neutron scattering soil moisture measurement system with a linear response.

A prototype moisture measurement system was designed and constructed, based on neutron scattering, for preforming measurements in the laboratory. The system consisted of a rectangular soil container, an 241Am/Be neutron source and two parallel 10BF3 detectors (one near the source and the other far from it). Neutrons from the source are moderated and backscattered within the soil sample before being detected by two parallel counters, whose count ratios are shown to be linearly related to the soil moisture even within short measurement times. The system's performance was demonstrated using the Monte Carlo simulations, and a series of measurements on soil samples made of clay (40 wt%) and sand (60 wt%), mixed with different percentages of water. The results showed that the detectors response ratio is linear, up to about 25% of water content.

[1]  Shenglu Zhou,et al.  Monitoring and prediction of soil moisture spatial–temporal variations from a hydropedological perspective: a review , 2012 .

[2]  E. Bakker,et al.  Estimating soil organic carbon through loss on ignition: effects of ignition conditions and structural water loss , 2015 .

[3]  M. Baghini,et al.  A critical review of soil moisture measurement , 2014 .

[4]  N. Elsheikh.  Multi-parameter optimization of a (3He-252Cf-3He) neutron backscattering sensor for landmine detection , 2017 .

[5]  N. M. Larson,et al.  ENDF/B-VII.1 Nuclear Data for Science and Technology: Cross Sections, Covariances, Fission Product Yields and Decay Data , 2011 .

[6]  J. Dietrich,et al.  Evaluation of SWAT simulated soil moisture at catchment scale by field measurements and Landsat derived indices , 2017 .

[7]  H. Vega-Carrillo,et al.  Few groups neutron spectra, and dosimetric features, of isotopic neutron sources. , 2016, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[8]  C. V. van Eijk,et al.  Landmine detection with the neutron backscattering method , 2000, 2000 IEEE Nuclear Science Symposium. Conference Record (Cat. No.00CH37149).

[9]  Richard T. Pagh,et al.  Compendium of Material Composition Data for Radiation Transport Modeling , 2011 .

[10]  G. Nebbia,et al.  A novel detector assembly for detecting thermal neutrons, fast neutrons and gamma rays , 2016 .

[11]  J. Novak,et al.  Non-invasive Field Measurements of Soil Water Content Using a Pulsed 14 MeV Neutron Generator , 2012 .

[12]  G. Knoll.  Radiation detection and measurement , 1979 .

[13]  C.W.E. van Eijk,et al.  Experimental results and Monte Carlo simulations of a landmine localization device using the neutron backscattering method , 2002 .

[14]  Effective crop evapotranspiration measurement using time-domain reflectometry technique in a sub-humid region , 2017, Theoretical and Applied Climatology.

[15]  R. K. Crawford,et al.  Position-sensitive detection of slow neutrons: survey of fundamental principles , 1993, Optics & Photonics.

[16]  Johan Alexander Huisman,et al.  Emerging methods for noninvasive sensing of soil moisture dynamics from field to catchment scale: a review , 2015 .