ANGULAR DIFFERENTIAL DOSE ALBEDO MEASUREMENTS FOR 0.66-Mev γ's INCIDENT ON CONCRETE, IRON, AND LEAD

Abstract

The angular dependence of the scattered dose produced by 0.66-Mev γ's incident on concrete, iron, and lead was measured for angles of incidence of 0°, 30°, and 60°. The angular distributions from these materials were dependent both on the angle of incidence and on the angle of scatter to a detector and could not be related to each other by simple multiplicative factors. As the angle of incidence increased, the scattering in the forward directions became increasingly anisotropic for each material. For iron exposed at normal incidence the effect of the scatterer thickness on the angular distribution of the scattered dose was measured also.A Monte Carlo program was used to study the distribution of distances between the point of incidence and the point at which a backscattered γ emerged and indicated that scatter from the "shadow" zone could be significant in some shielding studies. The program was used also to study the distribution of depths of the point at which a backscattered γ had its last scattering interaction.