A Magnetic Flux Guide for a SQUID Microscope

Abstract

The characteristics of magnetic flux transmission from the measurement point of a specimen to the SQUID through it magnetic flux guide are analyzed based on the experimentally-obtained magnetic field strength at each part of the flux guide. this analysis identifies the parameters that affect the performance of eddy current measurement systems based on a magnetic flux guide and a SQUID. With the parameters, a relationship is derived to calculate the sensitivity of the magnetic flux guide in the eddy current measurement system. The relationship will used to optimize the configurations of the sensing part of the system in design stage. It is also experimentally shown that shielding the magnetic flux guide will help to increase the spatial resolution in the system.