Weak magnetic field measurement appts. with SQUID and superconducting transformer circuit - has array of parallel-connected loops arranged on detector surface and coupled to current conductors

摘要

The measuring appts. includes a SQUID and a transformer circuit comprising an arrangement of detector loops for determining weak, changing magnetic fields from a biomagnetic field source. The signals from the detector loops are inductively coupled to the SQUID by coupling coils. The detection loops form at least one detection surface (F, F'), formed from an array of at least four elemental loops (29a-d, 30a-d). The transformer circuit pref. includes a detector loop arrangement forming a gradiometer of first order with parallel-connected elemental loops. USE/ADVANTAGE - For measuring biomagnetic fields e.g. from human heart or brain. Optimised flux transfer; reduced inductance of coupling coils.