Mobile HTS RF SQUID magnetometer

Using a simple compensation method, we developed a mobile HTS RF SQUID magnetometer. The dc and low frequency (below 20 Hz) magnetic field could be compensated very well. With the compensation, the HTS RF SQUID magnetometer remained locked while being swung at large angles in the Earth's field. For frequencies greater than 20 Hz, there was no increase in the flux noise observed after moving the SQUID system in the Earth's field. Using the mobile HTS RF SQUID magnetometer, we constructed an eddy current NDE system, which demonstrated the possibility of detecting defects in ferromagnetic materials.