Eddy current technique with high temperature SQUID for non-destructive evaluation of non-magnetic metallic structures

For the first time, a laboratory test system for non-destructive evaluation of metals using the eddy current technique in conjunction with a high temperature superconductor (HTS) SQUID gradiometer has been developed and set up in a magnetically unshielded laboratory environment. The first preliminary experiments prove the advantages of the technique with respect to low frequency sensitivity (large penetration depths), thus showing the potential of HTS SQUID eddy current systems.