Developments of a 3×3-matrix ROS magnetometer

摘要

We have developed a SQUID magnetometer with a configuration of a 3×3-matrix using relaxation oscillation SQUIDs (ROSs) with direct voltage readout. The size of a ROS is 2.5×2.5 mm{sup}2. The distance between the two ROSs is 4 mm and the whole size of the matrix is within 19 mm φ. With this system, we demonstrated measurements of the magnetic signals due to the action potential propagating through the peripheral nerve under the stimulus of the median nerve.