A MATHEMATICAL DERIVATION OF CONTOUR LINES FOR CONSTANT ALBEDO OF GAMMA RAYS ON CONCRETE,

The differential dose albedo of gamma rays on concrete depends on the energy of the incident gamma radiation, the polar angle of incidence, and the polar and azimuthal angles of backscatter. A mathematical method is developed to derive iso-albedic contours, i.e., contour lines on the surface of a hemisphere where backscattered radiation dose will be constant, when the angle of incidence is fixed and the point at which scattering occurs is at the center of the hemisphere. Graphs are presented showing iso-albedic contours for gamma radiation from Co-60 and Cs-137, incident at polar angles with cosines 1.00, 0.75, 0.50, 0.25, and 0.10. Author