Measurements of Ultrasonic Scattering from Bulk Flaws of Complex Shape

The report summarizes the design and early results of scattering experiments on fl aw.s of complex shape. In close collaboration with the varied theoretical groups representing different inversion algorithms, a unique set of diffusion bonded samples have been designed. These samples contain a variety of irregular and multiple flaws whose scattering characteristics will be obtained in order to guide and evaluate developments of theoretical approaches and test specific theoretical predictions. The majority of these samples have been received an.d the measurements have begun. Results on selected samples are presented an.d compared with scattering from ellipsoidal voids. The measurements will include angular, frequency and time domain variations of the scattered signals made possible with a new ultrasonic data acquisition system