High sensitive magnetometers and gradiometers based on dc SQUIDs with flux focuser
- Institute of Radio Engineering and Electronics, USSR Academy of Sciences, Marx Avenue 18, Moscow GSP-3 (SU)
This paper reports on high sensitive dc SQUID magnetometers and gradiometers with flux focusers instead of traditional coupling coils designed and experimentally tested. All refractory material DC SQUIDs with shunted Nb---AlO{sub x}---Nb tunnel junctions were used. The outer dimension of the square washer electrode was 2.5 mm, the inner one was 70{mu}m. A wide superconducting washer concentrates the magnetic flux by twenty times and the flux sensitivity about 20 nT/{phi}{sub 0} can be realized without any input coil. The application of the additional 14 mm diameter flux focuser has increased the flux concentration by four times more. As a result the magnetic field resolution 10 fT/square root Hz has been achieved; this figure corresponds to the flux resolution about 2 {center dot} 10{sup {minus}6}{phi}{sub 0}/square root Hz. Connecting the additional flux focuser to the placed apart compensation coils one can create gradiometers of both the first and higher orders.
- OSTI ID:
- 6089215
- Report Number(s):
- CONF-900944-; CODEN: IEMGA
- Journal Information:
- IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States), Vol. 27:2; Conference: 1990 applied superconductivity conference, Snowmass, CO (United States), 24-28 Sep 1990; ISSN 0018-9464
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
47 OTHER INSTRUMENTATION
42 ENGINEERING
ELECTROMAGNETIC PULSES
MULTI-CHANNEL ANALYZERS
MAGNETOMETERS
FABRICATION
SQUID DEVICES
ALUMINIUM OXIDES
BEAM OPTICS
CALCULATION METHODS
DESIGN
EDDY CURRENT TESTING
FOCUSING
MAGNETIC FLUX
NIOBIUM
SENSITIVITY
SUPERCONDUCTING JUNCTIONS
TUNNEL EFFECT
ALUMINIUM COMPOUNDS
CHALCOGENIDES
ELECTROMAGNETIC RADIATION
ELECTROMAGNETIC TESTING
ELECTRONIC EQUIPMENT
ELEMENTS
EQUIPMENT
FLUXMETERS
JUNCTIONS
MATERIALS TESTING
MEASURING INSTRUMENTS
METALS
MICROWAVE EQUIPMENT
NONDESTRUCTIVE TESTING
OXIDES
OXYGEN COMPOUNDS
PULSE ANALYZERS
PULSES
RADIATIONS
SUPERCONDUCTING DEVICES
TESTING
TRANSITION ELEMENTS
665412* - Superconducting Devices- (1992-)
440800 - Miscellaneous Instrumentation- (1990-)
420500 - Engineering- Materials Testing