Single layer YBaCuO-gradiometer

Daalmans, G.; Bär, L.; Kühnl, Michael; Uhl, D.; Selent, M.; Ramos, J.

doi:10.1109/77.403250

Cited by 20 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This configuration has the disadvantage that large supercurrents are induced around the perimeter when the device is rotated in an ambient field. Knappe et al (1992), Zakosarenko et al (1994), Daalmans et al (1995), Schultze, Stolz et al (1997), have all made single-layer, first-derivative gradiometers of this kind, using dc SQUIDs with either step-edge or bicrystal junctions. The baselines are limited by the size of the substrate to about 5 mm, and the best gradient sensitivities are about 50 pT m Ϫ1 Hz Ϫ1/2 .…”

Section: B Gradiometric Flux Transformersmentioning

confidence: 99%

High-transition-temperature superconducting quantum interference devices

et al. 1999

View full text Add to dashboard Cite

Section: B Gradiometric Flux Transformersmentioning

confidence: 99%

High-transition-temperature superconducting quantum interference devices

et al. 1999

View full text Add to dashboard Cite

“…The easiest and most common way to realize an integrated gradiometer with HTS material is by using the directly coupled SQUID [1][2][3], because it can be realized with one single superconducting layer. Due to the magnetometer SQUID, which reads out the signal from the gradiometer pick-up loop, the balance of the complete gradiometer is limited to the order of 100.…”

Section: State Of the Artmentioning

confidence: 99%

Highly balanced single-layer high-temperature superconductor SQUID gradiometer freely movable within the Earth s magnetic field

Schultze¹,

IJsselsteijn²,

May³

et al. 2003

Supercond. Sci. Technol.

View full text Add to dashboard Cite

We developed a gradiometer system based on a single-layer high-temperature superconductor dc superconducting quantum interference device (SQUID), which can be freely moved within the Earth's magnetic field during measurement. The problem of circumferential shielding currents in the parallel gradiometer pick-up loop is solved by the use of an appropriately designed magnetometer SQUID integrated on the gradiometer chip. The magnetometer's feedback coil of the flux-locked loop is laid out as a small Helmholtz coil pair, thus keeping the homogeneous magnetic field constant for both the magnetometer and the gradiometer. Therefore, the balance of the directly coupled gradiometer SQUID is enhanced from 100 up to 3800. The noise limited magnetic field gradient resolution of 45 pT m −1 Hz −1/2 is preserved down to frequencies of several Hz even after strong motion in the Earth's magnetic field.

show abstract

“…To reduce external interference by electrical compensation two schemes, both applying reference channels, were used [3]. In one mode, labelled • 1 in figure 2, the reference SQUID output signal was fed back inductively to the antenna of the signal channel.…”

Section: Read Out Electronicsmentioning

confidence: 99%

A niobium planar SQUID gradiometer operating in an unshielded environment

Bär¹,

Daalmans²,

Uhl³

et al. 1996

Supercond. Sci. Technol.

View full text Add to dashboard Cite

We present an integrated thin-film gradiometric SQUID sensor in Nb-Al/Al 2 O 3 -Nb technology. The dc-SQUID converter is designed as a parallel inductance double-washer SQUID. It is inductively coupled to a planar parallel inductance gradiometer antenna with 15 mm baseline by two series input coils with eight turns each. The field gradient sensitivity is 0.5 nT cm −1 −1 0 . The intrinsic field gradient resolution down to 1 Hz is 5 fT cm −1 Hz −1/2 , measured in a shielded environment.The sensor can be operated reliably without any magnetic shielding. Under these conditions the transfer function dV /d is decreased by about a factor of three, resulting in a field gradient resolution of 15 fT cm −1 Hz −1 in the white noise region.Coherent noise sources produced by a power line and railway were suppressed by means of electronic subtraction using a reference channel and selective filtering. The resolution of the system is demonstrated by MCG measurements without any shielding.

show abstract

Single layer YBaCuO-gradiometer

Cited by 20 publications

References 7 publications

High-transition-temperature superconducting quantum interference devices

High-transition-temperature superconducting quantum interference devices

Highly balanced single-layer high-temperature superconductor SQUID gradiometer freely movable within the Earth s magnetic field

A niobium planar SQUID gradiometer operating in an unshielded environment

Contact Info

Product

Resources

About