LTS Gradiometers Based-On Superconducting Imaging Surface Design

Abstract

Gradiometer-like devices can be built using a superconducting imaging surface design. Such devices behave similarly to conventional wire-wound gradiometers for nearby magnetic sources. A large gradiometer array can be built by placing SQUID magnetometers close to the surface of a large superconducting plane. The most attractive advantage of such a gradiometer array is the ability to change a baseline for all channels simultaneously by mechanically moving the superconducting imaging surface relative to the sensor array. This can easily be accomplished even when the gradiometer array is cold. We built, experimentally tested, and simulated both first- and second-order gradiometer-like devices with adjustable baseline using the superconducting imaging surface design. First-order radial gradiometer sensors were made by placing planar magnetometers parallel to and near the superconducting imaging surface. A second-order electronic gradiometer was realized by subtracting the output from two of the first-order gradiometers described above