Fluence Evaluations for Applications of In situ Gamma-Ray Spectrometry in Non-211 Flat Terrain

摘要

Evaluations of gamma-ray fluence are made for source geometries that depart from211u001ethe flat ground geometry that is used in standard applications of in situ 211u001espectrometry. Geometries considered include uniform source distributions for soil 211u001emounds on top of flat terrain, cylindrical wells, and rectangular trenches. The 211u001eresults indicate that scaling the standard fluence values for flat terrain by the 211u001eratio of solid angle subtended by the soil to 2B leads to fluence estimates that 211u001eare accurate to within a few percent. Practical applications of in situ 211u001espectrometry in non-flat terrain also appears to be simplified by the fact that 211u001ethe angular correction factor for a typical co-axial detector in these geometries 211u001emay typically be about the same as that computed for flat ground.