Title :
Pulsed operation of a superconductive electromagnetic gradiometer
Author :
Czipott, P.V. ; Podney, W.N.
Author_Institution :
SQM Technol. Inc., La Jolla, CA, USA
fDate :
3/1/1991 12:00:00 AM
Abstract :
An electromagnetic gradiometer (EMG) combines a superconducting quantum interference device (SQUID) gradiometer with an active magnetic source for use as an ultrasensitive metal detector. A report on performance tests of an EMG configuration using a pulsed source is presented. Eddy currents persist in metallic targets between pulses and thus make them visible to the receiver. Because the receiver only looks between pulses, when the source is off, it is immune to noise from source interference. Performance tests validate an analytical model that predicts a detection range of 20 m to a target 25 cm in radius for a prototype pulsed EMG producing pulses 10-ms long separated by 10-ms intervals, with a peak moment of 2×104 A-m2
Keywords :
SQUIDs; eddy currents; magnetometers; EMG configuration; active magnetic source; detection range; eddy currents; peak moment; pulsed source; source interference; superconducting quantum interference device; superconductive electromagnetic gradiometer; ultrasensitive metal detector; EMP radiation effects; Electromagnetic devices; Electromagnetic interference; Electromyography; Magnetic devices; Magnetic separation; SQUIDs; Superconducting devices; Superconductivity; Testing;
Journal_Title :
Magnetics, IEEE Transactions on
