Magnetic noise reducing device for a squid magnetometer.

摘要

A magnetic noise reducing device can effectively produce a practically noiseless space that can reduce environmental magnetic noise harmful for measuring biomagnetism with a high magnetism damping factor in low frequency range. The magnetic noise reducing device comprises a Superconducting Quantum Interference Devices (SQUID) flux meter 1 and a pair of noise cancelling coils 2 as minimum components, the feedback current I produced by the SQUID flux meter 1 being supplied to the noise cancelling coils 2, the magnetic flux detecting coil of the SQUID flux meter being arranged within a specific central space 4 defined by the noise cancelling coils 2 for effective reduction of magnetic noise within that space.