Thin-film dc squid gradiometer

Journal Article · Fri Dec 31 23:00:00 EST 1976 · IEEE Trans. Magn.; (United States)

DOI:https://doi.org/10.1109/TMAG.1977.1059485· OSTI ID:6887388

Ketchen, M B ^[1]; Goubau, W M; Clarke, J; Donaldson, G B

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1. Univ. of California, Berkeley

A thin-film dc SQUID gradiometer has been fabricated on a single planar substrate. The superconducting pick-up loops consist of a lead strip in the form of a 48 x 16 mm rectangle with a niobium strip bisecting the rectangle. A tunnel junction dc SQUID is symmetrically located on the niobium strip. If there is a spatial gradient in the magnetic field applied to the gradiometer so that the magnetic fluxes threading the two pick-up loops differ, a supercurrent is induced in the niobium strip that is detected by the SQUID. The noise power spectrum of the SQUID is white down to a frequency of about 5 x 10/sup -2/ Hz with a rms flux noise of 8 x 10/sup -5/ phi/sub 0/ Hz/sup -//sup /sup 1///sub 2/, corresponding to a gradient sensitivity of 2 x 10/sup -10/G cm/sup -1/ Hz/sup -//sup /sup 1///sub 2/.

• OSTI ID: 6887388
• Journal Information: IEEE Trans. Magn.; (United States), Journal Name: IEEE Trans. Magn.; (United States) Vol. MAG-13:1; ISSN IEMGA
• Country of Publication: United States
• Language: English

Related Subjects

420201* -- Engineering-- Cryogenic Equipment & Devices
440300 -- Miscellaneous Instruments-- (-1989)
47 OTHER INSTRUMENTATION
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
DESIGN
ELECTRONIC EQUIPMENT
FLUXMETERS
MAGNETOMETERS
MEASURING INSTRUMENTS
MICROWAVE EQUIPMENT
PERFORMANCE
SQUID DEVICES
SUPERCONDUCTING DEVICES