Patent ID: 6665552
Filing Date: 2003-12-16
Classification: G01R

Abstract:
A gradiometer integrated with pickup coils comprising:a first and a second pickup coils fabricated of a thin film on a substrate; and a differential SQUID fabricated of a thin film on said substrate and magnetically coupled to said first and second pickup coils, said differential SQUID including a first and a second superconducting loops connected in series or in parallel, wherein a first segment resulting from projecting a segment connecting the center of said first pickup coil with the center of said second pickup coil perpendicularly onto the surface of said substrate overlaps a second segment resulting from projecting a segment connecting the center of said first superconducting loop with the center of said second superconducting loop perpendicularly onto the surface of said substrate, wherein a midpoint of said first segment matches a midpoint of said second segment, and wherein said gradiometer integrated with pickup coils detects a field gradient in a z-direction with respect to an x-direction or a y-direction parallel with the surface of said substrate and perpendicular to the z-direction perpendicular to the surface of said substrate.