Unshielded use of thin-film Nb dc superconducting quantum interference devices and integrated asymmetric gradiometers for nondestructive evaluation

Walker, M.E.; Nakane, Hideaki; Cochran, A.; Weston, R. G.; Klein, U.; Pegrum, C.M.; Donaldson, G.B.

doi:10.1063/1.119450

Cited by 3 publications

(2 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At present, HTS single layer gradiometers are designed to be as symmetric as possible. Pickup loops of differing areas allow the device response to be tailored to a specific source configuration (LTS asymmetric gradiometers [6] already exist). Furthermore, recent work on an asymmetric flux transformer inductively coupled to an HTS directly coupled magnetometer shows promise [7].…”

Section: Device Design and Fabricationmentioning

confidence: 99%

High-temperature superconducting YBCO dc SQUID gradiometers fabricated on STO bicrystal substrates

Carr

Eulenburg

Romans

et al. 1998

Supercond. Sci. Technol.

View full text Add to dashboard Cite

HTS dc gradiometers have been fabricated with slots and flux dams in their SQUID washers. Using a single layer of YBCO, the gradient sensitivity is limited by the sensing magnetometer in the centre of the structure. The spatial response of such devices has been measured experimentally indicating that single layer devices, in terms of gradient sensitivity, have characteristics that deviate slightly from idealized first order gradiometers. The flux noise of these devices is discussed with particular emphasis on their unshielded low frequency noise properties. We also discuss the effect of different cooldown procedures on the flux noise.

show abstract

Section: Device Design and Fabricationmentioning

confidence: 99%

High-temperature superconducting YBCO dc SQUID gradiometers fabricated on STO bicrystal substrates

Carr

Eulenburg

Romans

et al. 1998

Supercond. Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…The intrinsic noise power spectral density of the bare SQUID is 4 goo Hz-'12 above 5 Hz [5]. The integrated planar gradiometer is an asymmetrical one fabricated with an all-niobium process on the same Si substrate of the SQUID [5] [6]. The precision with which this can be done means that very high intrinsic balance and excellent device to device repeatability are possible.…”

Section: Methodsmentioning

confidence: 99%

Non Destructive Testing using the SQUID with Integrated Gradiometer

et al. 1998

Self Cite

View full text Add to dashboard Cite

SummaryWe have used the integrated SQUID gradiometer in an unshielded environment to make eddy current nondestructive testing measurement on a multi-layer aluminum structure. The sensor consists of a niobium dc superconducting quantum interference device (SQUID) and a first-order gradiometer pick up coil on the same substrate. As a demonstration of their capabilities, subsurface defects in a multilayer aluminum structure have been located and mapped using eddy current with no magnetic shielding around the specimen or cryostat.

show abstract