Gamma backscattering experiments were performed on metal foils varying some geometric parameters of the assembly. A collimated beam from a 22Na source impinges on aluminum sheets of dimensions 33.3×20.4×1.0 cm3 and iron sheets of (33.2×20.4×0.2) cm3. The backscattered photons are detected by a 3″×3″ CsI scintillator detector placed at 90° to the incident beam. The experimental results show that thickness of metalic samples can be determined with a very small uncertainty.
