Measurement of the Radiation-Induced Conductivity of Soil

The transient, radiation-induced conductivity (RIC) of a variety of types of soils has been measured using an electron beam from the AURORA simulator. The coefficient of RIC, K¿, was found to be between 1 and 3×10-16 (S/cm)/(rad/s) for most samples at a dose rate of ¿ = 2×1013 rad/s, although there were variations due to sample type and water content. A model was formulated in which all samples are described by a three component system of: dielectric grains, water, and air pores. The conductivity of dry soil is found to be dominated by the air component, and K¿ is expected to decrease with ¿ in agreement with the data. An expected decrease of the RIC for increased water content in a given type of soil was not consistently demonstrated.