Effect of sample and magnetometer dimensions on the flux detected by a SQUID magnetometer

Abstract

From the Green’s function for the magnetic scalar potential inside an infinitely long superconducting shield, an expression is obtained for the flux within a circular pickup coil due to a cylindrical sample of arbitrary dimensions. Using this expression, the dependence of SQUID output on sample dimensions and pickup coil and shield radii is derived. The predictions are found to be in good agreement with experimental measurements.