Near-Field Linear Sampling Method forAxisymmetric Eddy Current Tomography

TL;DR

This paper extends the Linear Sampling Method to Eddy-Current testing for nondestructive shape identification of deposits in conductive materials, demonstrating its effectiveness with limited coil data and backscattering measurements.

Contribution

The paper develops a theoretical and practical adaptation of the LSM for EC tomography, enabling shape detection with fewer coils and in more realistic scenarios.

Findings

Effective shape identification with limited coil data

Successful application to backscattering measurements

Theoretical foundation for EC LSM adaptation

Abstract

This paper is concerned with Eddy-Current (EC) nondestructive testing of conductive materials and focuses, in particular, on extending the well-known LinearSampling Method (LSM) to the case of EC equations. We first present the theoretical foundation of the LSM in the present context and in the case of point sources. We then explain how this method can be adapted to a realistic setting of EC probes. In the case of identifying the shape of external deposits from impedance measurements taken from inside of the tube (steam generator), we show how the method can be applied to measurements obtained from a sweeping set of coils. Numerical experiments suggest that good results can be achieved using only a few coils and even in the limiting case of backscattering data.