A random matrix approach to detect defects in a strongly scattering polycrystal: how the memory effect can help overcome multiple scattering

Sharfine Shahjahan; Alexandre Aubry; Fabienne Rupin; Bertrand Chassignole; Arnaud Derode

doi:10.1063/1.4882421

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arXiv · 1405.6526

A random matrix approach to detect defects in a strongly scattering polycrystal: how the memory effect can help overcome multiple scattering

Sharfine Shahjahan·Alexandre Aubry·Fabienne Rupin·Bertrand Chassignole·Arnaud Derode

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Abstract

We report on ultrasonic imaging in a random heterogeneous medium. The goal is to detect flaws embedded deeply into a polycrystalline material. A 64-element array of piezoelectric transmitters/receivers at a central frequency of 5 MHz is used to capture the Green's matrix in a backscattering configuration. Because of multiple scattering, conventional imaging completely fails to detect the deepest flaws. We utilize a random matrix approach, taking advantage of the deterministic coherence of the backscattered wave-field which is characteristic of single scattering and related to the memory effect. This allows us to separate single and multiple scattering contributions. As a consequence, we show that flaws are detected beyond the conventional limit, as if multiple scattering had been overcome.

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Sharfine Shahjahan, Alexandre Aubry, Fabienne Rupin, Bertrand Chassignole, Arnaud Derode. 2014-05-26. A random matrix approach to detect defects in a strongly scattering polycrystal: how the memory effect can help overcome multiple scattering. https://doi.org/10.1063/1.4882421

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