Design and performance of integrated DC SQUID gradiometers
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Integration of thin film gradiometers with a dc superconducting quantum interference device (SQUID) is described. A parallel first-order gradiometer has been realized with an overall size of 17 mm × 12 mm and a sensitivity of typically 3 × 10-12Tm-1Hz-1/2. An intrinsic balance of 300 ppm is easily achieved. Its usefulness for measuring biomagnetic signals is shown. A novel design for a second order gradiometer consisting of eight second order loops in parallel is presented. The design is based on a sensitivity of 3 × 10-10Tm-2Hz-1/2with a size of 17mm × 17mm and a SQUID inductance of 1nH.
[1] J. E. Zimmerman,et al. Sensitivity Enhancement of Superconducting Quantum Interference Devices through the Use of Fractional‐Turn Loops , 1971 .
[2] J. Bruines,et al. Comment on: “Dc SQUID: Noise and optimization” by Tesche and Clarke , 1982 .
[3] John Clarke,et al. Superconducting thin‐film gradiometer , 1978 .
[4] John Clarke,et al. dc SQUID: Noise and optimization , 1977 .
[5] J. Mooij,et al. Very low noise all-niobium DC SQUIDs , 1981 .