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Title: Low-noise SQUID

Abstract

The present invention comprises a high-transition-temperature superconducting device having low-magnitude low-frequency noise-characteristics in magnetic fields comprising superconducting films wherein the films have a width that is less than or equal to a critical width, w.sub.C, which depends on an ambient magnetic field. For operation in the Earth's magnetic field, the critical width is about 6 micrometers (.mu.m). When made with film widths of about 4 .mu.m an inventive high transition-temperature, superconducting quantum interference device (SQUID) excluded magnetic flux vortices up to a threshold ambient magnetic field of about 100 microTesla (.mu.T). SQUIDs were fabricated having several different film strip patterns. When the film strip width was kept at about 4 .mu.m, the SQUIDs exhibited essentially no increase in low-frequency noise, even when cooled in static magnetic fields of magnitude up to 100 .mu.T. Furthermore, the mutual inductance between the inventive devices and a seven-turn spiral coil was at least 85% of that for inductive coupling to a conventional SQUID.

Inventors:
 [1];  [2]
  1. Torrance, CA
  2. Berkeley, CA
Issue Date:
Research Org.:
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
OSTI Identifier:
872850
Patent Number(s):
6023161
Assignee:
Regents of University of California (Oakland, CA)
Patent Classifications (CPCs):
G - PHYSICS G01 - MEASURING G01R - MEASURING ELECTRIC VARIABLES
Y - NEW / CROSS SECTIONAL TECHNOLOGIES Y10 - TECHNICAL SUBJECTS COVERED BY FORMER USPC Y10S - TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
low-noise; squid; comprises; high-transition-temperature; superconducting; device; low-magnitude; low-frequency; noise-characteristics; magnetic; fields; comprising; films; width; equal; critical; depends; ambient; field; operation; earth; micrometers; film; widths; inventive; transition-temperature; quantum; interference; excluded; flux; vortices; threshold; 100; microtesla; squids; fabricated; strip; patterns; kept; exhibited; essentially; increase; noise; cooled; static; magnitude; furthermore; mutual; inductance; devices; seven-turn; spiral; coil; 85; inductive; coupling; conventional; ambient magnetic; superconducting film; quantum interference; magnetic flux; magnetic field; magnetic fields; temperature superconducting; static magnetic; superconducting quantum; interference device; superconducting device; mutual inductance; frequency noise; superconducting films; conducting films; inductive coupling; comprising superconducting; film strip; conducting film; transition-temperature superconducting; high-transition-temperature superconducting; low-noise squid; /324/505/

Citation Formats

Dantsker, Eugene, and Clarke, John. Low-noise SQUID. United States: N. p., 2000. Web.
Dantsker, Eugene, & Clarke, John. Low-noise SQUID. United States.
Dantsker, Eugene, and Clarke, John. Sat . "Low-noise SQUID". United States. https://www.osti.gov/servlets/purl/872850.
@article{osti_872850,
title = {Low-noise SQUID},
author = {Dantsker, Eugene and Clarke, John},
abstractNote = {The present invention comprises a high-transition-temperature superconducting device having low-magnitude low-frequency noise-characteristics in magnetic fields comprising superconducting films wherein the films have a width that is less than or equal to a critical width, w.sub.C, which depends on an ambient magnetic field. For operation in the Earth's magnetic field, the critical width is about 6 micrometers (.mu.m). When made with film widths of about 4 .mu.m an inventive high transition-temperature, superconducting quantum interference device (SQUID) excluded magnetic flux vortices up to a threshold ambient magnetic field of about 100 microTesla (.mu.T). SQUIDs were fabricated having several different film strip patterns. When the film strip width was kept at about 4 .mu.m, the SQUIDs exhibited essentially no increase in low-frequency noise, even when cooled in static magnetic fields of magnitude up to 100 .mu.T. Furthermore, the mutual inductance between the inventive devices and a seven-turn spiral coil was at least 85% of that for inductive coupling to a conventional SQUID.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}

Works referenced in this record:

Integrated YBa 2 Cu 3 O 7− x magnetometer for biomagnetic measurements
journal, March 1996


High-Tc super conducting quantum interference devices with slots or holes: Low 1/f noise in ambient magnetic fields
journal, April 1997


Low-noise, single-layer YBa/sub 2/Cu/sub 3/O/sub 7-x/ DC SQUID magnetometers at 77 K
journal, June 1995