Experimental and numerical results of electromagnetic nondestructive testing with HTcSQUIDs

We present here recent results on detection of surface and subsurface artif icial features in Al-Ti planar structures, to show current performance of o ur eddy-current nondestructive evaluation system based on HTc SQUIDs. The a nomalous magnetic fields generated by flaws with known electromagnetic char acteristics have been modeled by three-dimensional codes based on Finite El ement Method and Volume Integral Formulation and developed for the investig ated problem. Both numerical solutions have correctly predicted the shape o f the complicated magnetic field response which is mainly the results of th e shape of the defect, the geometry of the inducing coil and the characteri stics of the SQUID gradiometer.