Substrate resonator for HTS rf SQUID operation

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Abstract-We have demonstrated and verified the basic feasibility of performing magnetocardiographic (MCG) measurements without magnetic shielding when using a first-order electronic gradiometer with our novel dielectric substrate resonator rf SQUID's. The setup at the operation site involved adjustment of the gradiometer's baseline length and adaptive balancing. Our experimental portable system was tested in three environments differing in the level of electromagnetic interference.

Section: Substrate Resonator Conceptmentioning

confidence: 96%

“…R ECENTLY, we developed a first-order electronic gradiometer incorporating our novel dielectric substrate resonator rf SQUID's having high sensitivity [1]. In this work, we report on experimental verification that the system is well suited for performing MCG measurements in unshielded environment.…”

Section: Introductionmentioning

confidence: 99%

HTS SQUID gradiometer using substrate resonators operating in an unshielded environment - A portable MCG system

Zhang

Wolters

Schubert

et al. 2003

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“…may be safely detected, the limit of safe detection at an arbitrary position in the functional orifice is . As SQUID sensors, HTS rf SQUID magnetometers with 3.5 mm YBCO washers, loop and step-edge junctions were used in conjunction with 10 mm 10 mm substrate resonators (effective area 0.65 ) [7]. In order to attain a robust industry-grade setup satisfying the strict rules of pharmacological and food industry, a cryostat made of stainless steel was manufactured (Juelicher SQUID GmbH).…”

Section: System Design and Setupmentioning

confidence: 99%

Detection of Magnetic Contaminations in Industrial Products Using HTS SQUIDs

Krause

Panaitov

Wolters

et al. 2005

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Abstract-Many products in the pharmaceutical and food industry are packaged in metallized wrappings. With standard high-frequency search coil metal detectors, they can only be tested for metal contaminations before they are wrapped. However, a key requirement of industrial quality control is the inspection of the products at the end of the production line. We have developed an inspection system for detecting the magnetic remanence of the contaminants. The system utilizes two HTS rf SQUID magnetometers with step edge junctions immersed in liquid nitrogen. The SQUIDs are arranged such that they cover the product channel in a rotated planar electronic gradiometer configuration. In order to suppress the low-frequency magnetic disturbances typically found in industrial environment, the product channel and the SQUID system were mounted inside a coaxial three-layer Mumetal shield. In combination with the gradiometric suppression, homogeneous low-frequency disturbance fields were attenuated by a factor of 400,000. The sensitivity of the system for small magnetic particles was determined experimentally, using numerous steel balls and splinters. A stainless steel particle of 3 g, corresponding to a sphere diameter of 0.09 mm, was detected with and without aluminized wrapping.

“…As rf-tank circuit, we used a SrTiO substrate resonator, which resonates at about 600 MHz. Details of the rf-SQUID with substrate resonator we have used, can be found in [11]. The inductive coupling between SQUID and flux transformer was changed by a fine mechanical variation of the distance between two substrates.…”

Section: B Gradiometer Arrangementmentioning

confidence: 99%

Long baseline hardware gradiometer based on HTS rf-SQUIDs with substrate resonators

Panaitov

Zhang

Krause

et al. 2003

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Abstract-We have developed an asymmetric thin film first order gradiometer based on an HTS rf-SQUID. A coupling scheme uses an SrTiO 3 substrate resonator as an rf-tank circuit which simplifies the gradiometer balancing. Advantage of the technique is that gradiometers with very long baseline can be fabricated. The performance of 13 mm and 33 mm baseline SQUID gradiometers is presented. The gradiometers have been successfully used in applications for nondestructive evaluation of materials.