Magnetic Shielding Simulation of Superconducting Film Magnetic Shield Covering Directly Coupled HTS dc-SQUID Magnetometer

An HTS SQUID magnetometer is a highly sensitive magnetic sensor. The SQUID magnetometer is, however, susceptible to magnetic noise. Hence, to enhance the robustness of the SQUID magnetometer with respect to magnetic noise, a cover with a superconducting film magnetic shield has been proposed. The superconducting film magnetic shield improves the robustness with respect to magnetic noise and widens the effective area of the SQUID sensor. It was also confirmed that the shape of the superconducting film magnetic shield affected the effectiveness in the magnetic shield in experiments. In our research, we have carried out a magnetic shielding simulation of the SQUID magnetometer covered with the superconducting film magnetic shield by using a 3D edge finite element method. To clarify the influence of the shape of the superconducting film magnetic shield on the effective area of the SQUID sensor, the simulation concerning a few shapes of the superconducting film magnetic shield was carried out. In order to evaluate the effectiveness of the superconducting film magnetic shield, the supercurrent inside the SQUID magnetometer and the superconducting film magnetic shield are simulated. From the simulation results, it is confirmed that the effective area of the SQUID sensor is widened by attaching the superconducting film magnetic shield over the SQUID ring.