The Leading Edge; January 2008; v. 27; no. 1;
p. 70-74; DOI: 10.1190/1.2831682
© 2008 Society of Exploration Geophysicists
Application of high-temperature superconductor SQUIDs for ground-based TEM
K. E. Leslie,
R. A. Binks,
S. K. H. Lam,
P. A. Sullivan,
D. L. Tilbrook,
R. G. Thorn and
C. P. Foley
CSIRO, Sydney, Australia
Corresponding author: Keith.Leslie{at}csiro.au
Superconducting quantum interference devices (SQUIDs) are intrinsically very sensitive detectors of magnetic flux. Flux sensitivities of one millionth of a flux quantum per root Hz (1µ
0/
Hz) may typically be realized in low-temperature superconductor (LTS) materials, while sensitivities of
5µ
0/
Hz may be realized in high-temperature superconductor (HTS) materials. LTS devices are typically cooled with liquid helium (4 K) while HTS devices are typically cooled with liquid nitrogen (77 K). Coupling the magnetic field into a SQUID via a flux-transformer can result in a very sensitive magnetometer with, depending on the type of superconducting material used and the effective area of the flux-coupling transformer, achievable magnetic field sensitivities ranging from fT/
Hz to pT/
Hz over typical bandwidths that span hundreds of kHz. SQUID applications include NDE, biomagnetism and magnetic microscopes.
Copyright © 2008 by Society of Exploration Geophysicists