Design aspects of a gamma-ray energy-spectral Compton-scatter nondestructive testing method

Methods for resolving the direction of scattering from the gamma-ray energy spectrum in Compton-scatter nondestructive testing are examined. With good source collimation and a well-confined detectorʹs field-of-view, it is shown that scattering angles can be directly determined from the energy-calibrated pulse-height distribution, without numerical unfolding. Factors affecting this process are studied and system-design guidelines are outlined. The application of the technique for the detection of multiple collinear flaws, as well as to inspect a multilayered structure, is successfully demonstrated.