Abstract: According to one embodiment, an apparatus comprises a magnet assembly to produce a static magnetic field and a set of high-Tc flux transformers to detect a flux change from an item when the item is subjected to the static magnetic field produced by the magnet assembly and to produce a current based on the flux change. Additionally, the apparatus comprises a set of magnetoresistive sensors to detect a field produced by a current produced in the set of high-Tc flux transformers and a scanning mechanism to produce cyclic relative motion between the apparatus and the item. Furthermore, the apparatus comprises a magnetic shield to shield the magnetoresistive sensors, where the shield is an open ended cylinder made from mu-metal, where mu-metal is a very high magnetic permeability iron-nickel alloy. The apparatus additionally comprises a water interface mechanism to fill a gap between the apparatus and the item with water.

Abstract: According to one embodiment, an apparatus comprises a magnet assembly to produce a static magnetic field and a set of high-Tc flux transformers to detect a flux change from an item when the item is subjected to the static magnetic field produced by the magnet assembly and to produce a current based on the flux change. Additionally, the apparatus comprises a set of magnetoresistive sensors to detect a field produced by a current produced in the set of high-Tc flux transformers and a scanning mechanism to produce cyclic relative motion between the apparatus and the item. Furthermore, the apparatus comprises a magnetic shield to shield the magnetoresistive sensors, where the shield is an open ended cylinder made from mu-metal, where mu-metal is a very high magnetic permeability iron-nickel alloy. The apparatus additionally comprises a water interface mechanism to fill a gap between the apparatus and the item with water.