Title :
DC-SQUID sensor system for multichannel neuromagnetometry
Author :
Houwman, E.P. ; Veldhuis, D. ; Flokstra, J. ; ter Brake, H.J.M. ; Jaszczuk, W. ; Martinez, A. ; Rogalla, H.
Author_Institution :
Fac. of Appl. Phys., Twente Univ., Enschede, Netherlands
fDate :
3/1/1991 12:00:00 AM
Abstract :
Various DC SQUID sensor configurations were developed for use in a 19-channel neuromagnetometer. Apart from the standard type, resistively and inductively shunted SQUIDs were made, allowing for a large screening factor β (>1). In this way, signal coupling from the pickup coil to the SQUID is facilitated and can be decreased. The number of turns of the input coil is decreased further by allowing for an inductance mismatch in the input circuit. Although theoretically both measures give rise to an increased field noise of the sensor, they may lead to a reduction of the excess noise and the noise balance may become positive
Keywords :
SQUIDs; biomagnetism; biomedical equipment; biomedical measurement; electric sensing devices; magnetic field measurement; magnetometers; DC SQUID sensor configurations; excess noise; field noise; inductance mismatch; inductively shunted; input coil; multichannel neuromagnetometry; noise balance; pickup coil; resistively shunted; screening factor; signal coupling; Circuit noise; Coils; Coupling circuits; Inductance; Magnetic field measurement; Magnetic noise; SQUIDs; Sensor systems; Stripline; Voltage;
Journal_Title :
Magnetics, IEEE Transactions on
