Evaluation of Drung-type magnetometers for multi-channel systems

Abstract

The properties of a prototype Drung-type SQUID with single-digit or smaller dynamic resistance, decreased using asymmetric bias current injection, are examined. Magnetic field resolution of 2.2 fT Hz-1/2 at 1 kHz and high sensitivity are obtained. A highly reliable ceramic package is developed for multi-channel applications. A prototype 256-channel system for biomagnetic application using mass-produced SQUIDS is built, and the successful operation of 206 channels is verified.