论文信息 - Coupling considerations for SQUID devices

Coupling considerations for SQUID devices

Most applications of superconducting quantum interference devices (SQUID’s) involve use of a coupling coil. There are two classes of such applications: magnetometry (magnetic field, field gradient) and voltage or current measurements. We have analyzed the factors which determine the ultimate sensitivity, and present a guide for optimization of signal/noise in each of the two cases. It is found that a single figure of merit, involving both the equivalent input noise of the SQUID and the effectiveness of the coupling to the coil, is applicable to either type of measurement. We propose that this figure of merit be used in evaluating the performance of new SQUID designs.

J. Claassen

[1] A. Davidson,et al. An ultra‐low‐noise preamplifier using superconducting quantum devices , 1974 .

[2] J. Kurkijärvi. Noise in the superconducting quantum flux detector , 1973 .

[3] W. Webb. Superconducting quantum magnetometers , 1972 .

[4] R. A. Webb,et al. Principles and methods of low-frequency electric and magnetic measurements using an rf-biased point-contact superconducting device , 1972 .

[5] J. E. Zimmerman,et al. Sensitivity Enhancement of Superconducting Quantum Interference Devices through the Use of Fractional‐Turn Loops , 1971 .

[6] J. Goodkind,et al. The Superconducting Magnetic Flux Detector , 1970 .

[7] J. Zimmerman,et al. Design and Operation of Stable rf‐Biased Superconducting Point‐Contact Quantum Devices, and a Note on the Properties of Perfectly Clean Metal Contacts , 1970 .

[8] V. L. Newhouse,et al. An ultrasensitive linear cryotron amplifier , 1964 .

[9] W. L. Goodman,et al. Superconducting instrument systems , 1973 .

[10] J. Clarke,et al. Low-frequency applications of superconducting quantum interference devices , 1973 .

[11] V. Newhouse,et al. Noise Analysis for Amplifiers with Superconducting Input , 1971 .

[12] W. Webb,et al. Versatile Superconducting Femtovolt Amplifier and Multimeter , 1971 .

[13] J. Clarke,et al. A superconducting galvanometer employing Josephson tunnelling , 1966 .