A flip-chip-type gradiometer has been constructed with a 10 mm × 5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YB-CO* /YBCO/CeO2/YSZ multilayer on...A flip-chip-type gradiometer has been constructed with a 10 mm × 5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YB-CO* /YBCO/CeO2/YSZ multilayer on a φ50.8 mm Si wafer. The coupling coefficient between the flux transformer and the planar gradiometer is 0.18. The transformer increases effectively the resolution of the gradiometer. A magnetic field gradient resolution of 73 fT·cm-1·Hz-1/2 in the white region and 596 fT·cm-1Hz-1/2 at 1 Hz has been obtained. High quality magnetocardiogram signals have been successfully measured by using this flip-chip-type gradiometer in an unshielded environment.展开更多
文摘A flip-chip-type gradiometer has been constructed with a 10 mm × 5 mm planar DC-SQUID gradiometer fabricated on a SrTiO3 bicrystal substrate and a flux transformer made from a YB-CO* /YBCO/CeO2/YSZ multilayer on a φ50.8 mm Si wafer. The coupling coefficient between the flux transformer and the planar gradiometer is 0.18. The transformer increases effectively the resolution of the gradiometer. A magnetic field gradient resolution of 73 fT·cm-1·Hz-1/2 in the white region and 596 fT·cm-1Hz-1/2 at 1 Hz has been obtained. High quality magnetocardiogram signals have been successfully measured by using this flip-chip-type gradiometer in an unshielded environment.
