A modular low noise 7-channel SQUID-magnetometer

Conference · Fri Mar 01 04:00:00 EST 1991 · IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:5921491

Dossel, O; David, B; Fuchs, M; Kullmann, W H; Ludeke, K M ^[1]

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1. Philips GmbH, Forshchungslaboratorium Hamburg, Postfach 54 08 40, 2000 Hamburg 54 (DE)

This paper reports on a modular low noise 7-channel SQUID-magnetometer for biomagnetic measurements. The DC-SQUIDs are prepared by thin film technology based on the materials NbN-MgO-NbN and show a flux noise below 10{mu}{phi}{sub 0}/square root of Hz. The signal is picked up with first order wirewound gradiometers of 2cm diameter and coupled to the SQUIDs by integrated coupling coils. Individual channels can be replaced from the system and various gradiometers can be used giving a flexible modular system. The electronics are based on the flux locked loop method extended by a new bias modulation technique to reduce 1/f noise. The overall system noise is below 20 ft. square root Hz. Biomagnetic measurements on auditory evoked fields have been carried out.

• OSTI ID: 5921491
• Report Number(s): CONF-900944--
• Conference Information: Journal Name: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States) Journal Volume: 27:2
• Country of Publication: United States
• Language: English

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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COUPLING
ELECTRONIC CIRCUITS
ELECTRONIC EQUIPMENT
EQUIPMENT
FABRICATION
FILMS
FLUXMETERS
INTEGRATED CIRCUITS
MAGNETIC FLUX
MAGNETOMETERS
MEASURING INSTRUMENTS
MICROELECTRONIC CIRCUITS
MICROELECTRONICS
MICROWAVE EQUIPMENT
MODE LOCKING
NIOBIUM COMPOUNDS
NIOBIUM NITRIDES
NITRIDES
NITROGEN COMPOUNDS
NOISE
PNICTIDES
REFRACTORY METAL COMPOUNDS
SQUID DEVICES
SUBSTRATES
SUPERCONDUCTING DEVICES
SUPERCONDUCTING FILMS
TEMPERATURE NOISE
TRANSITION ELEMENT COMPOUNDS