SQUID SENSOR USING AUXILIARY SENSOR

摘要

PURPOSE: A SQUID(Superconducting QUantum Interference Device) sensor using an auxiliary sensor is provided to reduce the noise by generating the offset magnetic field having the noise of higher level than the self-noise of the SQUID sensor. CONSTITUTION: A SQUID sensor portion(10) is formed with a feedback coil for generating the magnetic field of a SQUID and the magnetic field around the SQUID. An auxiliary magnetic sensor portion(20) is formed with a low magnetic sensitivity and large operation range. A SQUID driving portion(40) and an auxiliary sensor driving portion(30) operate the SQUID sensor portion(10) and the auxiliary sensor portion(20) in order to signals of SQUID. The first combination portion(50) combines the magnetic filed of the SQUID driving portion(40) with the magnetic field of the auxiliary sensor driving portion(30) in order to supply the offset magnetic field to the SQUID sensor portion(10). The second combination portion(60) adds the output of SQUID sensor portion(10) to the output of the auxiliary magnetic sensor portion(20) in order to output a noiseless final resultant.