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High-T(sub c) squid application in medicine and geophysicsIn the Laboratory a high-T(sub c) one-hole squid was built from Y1Ba2Cu3O(7-x) ceramics obtained by a standard procedure of solid state reaction. The ceramics with critical current density J(sub c) is greater than 100 A/sq cm was selected. In the middle of 10 x 10 x 2 mm ceramics pellet a 0.8 mm hole was drilled in which superconducting loop of the squid was located. Between the hole and the edge of the pellet a cut was mechanically filed out with a bridge inside it connecting the superconducting ring. A scheme of the magnetometer is presented. The resonant frequency shift of the tank circuit, the connection of the squid with this circuit, and the squid inductance are evaluated. One of the most interesting fields of the squid-based magnetometer application is biomagnetism, particularly, the human heart magnetocardiogram measuring. The low-temperature squids were used in this area and many interesting and important scientific results have been obtained. The observations have shown that the main noise contribution was not due to the squid but to the Earth's magnetic field variations, industrial inductions, and mainly to the vibrations caused by liquid nitrogen boiling and by vibrations of the box. Further attempts are needed to reduce the magnetic noise inductions. Nevertheless, the estimations promise the maximum signal/noise relation of the high-T(sub c) squid-magnetocardiometer to be not less than 10:1 in a bandwidth of 60 Hz. Apparently, such resolution would be enough not only for steady cardiogram reading but even for thin structure investigation at average technique application.
Document ID
19900018490
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Polushkin, V. N.
(Joint Inst. for Nuclear Research Dubna, Ussr)
Uchaikin, S. V.
(Joint Inst. for Nuclear Research Dubna, Ussr)
Vasiliev, B. V.
(Joint Inst. for Nuclear Research Dubna, Ussr)
Date Acquired
September 6, 2013
Publication Date
April 1, 1990
Publication Information
Publication: NASA, Goddard Space Flight Center, AMSAHTS 1990: Advances in Materials Science and Applications of High Temperature Superconductors
Subject Category
Nonmetallic Materials
Accession Number
90N27806
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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