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一、原理中子法测定土壤含水量,是应用快中子源所放出的快中子被土壤中氢原子慢化后,用慢中子探测器所测到的慢中子流强度来求得。由中子散射理论,氢原子核是快中子最强的慢化体,而土壤中几乎所有的氢都存在于水分中,所以土壤中快中子的慢化能力与土壤含水量有密切的关系。快中子与原子核作用的基本过程是散射,其俘获截面只有散射截面的几十分之一、几百分之一、或更小。快中子在减速过
First, the principle Neutron method for the determination of soil moisture, is the application of fast neutron emitted by the neutron source is slowed by the hydrogen atoms in the soil, slow neutron detector measured by slow neutron flux intensity to obtain . According to the theory of neutron scattering, hydrogen nuclei are the most fast moderators of fast neutrons, and almost all of the hydrogen in the soil exists in the water, so the moderating ability of fast neutrons in the soil is closely related to the soil moisture content . The basic process of fast neutron-nucleus interaction is scattering. The capture cross section is only a fraction of the scattering cross section, a few hundredths, or less. Fast neutrons are slowing down