Imaging characteristics of a new magnetic microprobe with spatial differentiation property

Abstract

AbstractA new type of magnetic microprobe by which surface anomalies of magnetic or conductive materials can be detected with enhanced spatial resolution and sensitivity is presented. The probe is fabricated using a pair of thin amorphous wires bent in a U‐shape, on each of which two identical copper wire coils are wound. Four identical coils are connected so as to make a bridge circuit, in which two positively coupled coils on the same wire core are placed on opposite sides of the bridge circuit (with positive mutual coupling). The characteristics of the new probe, including the point spread function (PSF), spatial resolution, and sensitivity, are compared with those of a Dahle microprobe having the same assembly but with the connections of the four coils changed. © 2001 Scripta Technica, Electr Eng Jpn, 135(2): 9–16, 2001