A Mössbauer backscatter system has been designed which is capable of 130% resonance effect for a rolled foil stainless-steel sample having an elliptical-shaped scatter area of 6.46 in.2. This effect is a function of the surface area of the sample and the energy of the detected photon. For a sample surface area greater than 0.5 in.2, the 14.4-keV γ ray is the most efficient. This system is significant for nondestructive testing because sampling times are decreased to minutes. © 1969 The American Institute of Physics.