EDDY-CURRENT TECHNIQUE WITH HIGH-TEMPERATURE SQUID FOR NONDESTRUCTIVEEVALUATION OF NONMAGNETIC METALLIC STRUCTURES

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