High-temperature superconducting quantum interference device with cooled LC resonant circuit for measuring alternating magnetic fields with improved signal-to-noise ratio
- Institute of Bio- and Nanosystem (IBN-2), Research Center Juelich, D-52425 Juelich (Germany) and Pohl Institute of Solid State Physics, Tongji University, Shanghai 200092 (China)
Certain applications of superconducting quantum interference devices (SQUIDs) require a magnetic field measurement only in a very narrow frequency range. In order to selectively improve the alternating-current (ac) magnetic field sensitivity of a high-temperature superconductor SQUID for a distinct frequency, a single-coil LC resonant circuit has been used. Within the liquid nitrogen bath, the coil surrounds the SQUID and couples to it inductively. Copper coils with different numbers of windings were used to cover the frequency range from <1 to nearly 100 kHz. A superconducting coil made of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} tape conductor was also tested. With the LC circuit, the signal-to-noise ratio of measurements could be improved typically by one order of magnitude or more in a narrow frequency band around the resonance frequency exceeding a few kilohertz. The best attained equivalent magnetic field resolution was 2.5 fT/{radical}Hz at 88 kHz. The experimental findings are in good agreement with mathematical analysis of the circuit with copper coil.
- OSTI ID:
- 20953454
- Journal Information:
- Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 5 Vol. 78; ISSN 0034-6748; ISSN RSINAK
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALTERNATING CURRENT
BARIUM COMPOUNDS
COPPER
HIGH-TC SUPERCONDUCTORS
KHZ RANGE 01-100
LIQUIDS
MAGNETIC FIELDS
MAGNETOMETERS
NITROGEN
RESOLUTION
SIGNAL-TO-NOISE RATIO
SQUID DEVICES
SUPERCONDUCTING COILS
TEMPERATURE RANGE 0400-1000 K
YTTRIUM COMPOUNDS