A novel system for measuring effectiveness of magnetic shields in a liquid helium Dewar with a fluxgate magnetometer

Abstract A novel system which is specially designed for measuring effectiveness of small-scale magnetic shields in a liquid helium Dewar introduced this paper. This mainly applied to test the shielding performance multilayer structure used field single-flux-quantum (SFQ) electronics testing at temperature. allows using fluxgate magnetometer measure flux instead superconducting quantum interference device (SQUID) method. The can be put into through circular channel connected with ambient environment. Thus, both and absolute obtained by system. In addition, environmental field, improves measurement accuracy. By utilizing system, shield four-layer manufactured low-temperature permalloy material was measured. experimental results shows that axial (SE) 58.3 dB. comparison between theoretical verified