High-symmetry DC SQUID based on the Nb/AlOx/Nb Josephson junctions for nondestructive evaluation

Abstract

Topology of high-symmetry thin-film SQUIDs based on the Nb/AlO_x/Nb tunneling junctions is developed and optimized. The devices exhibit relatively low sensitivity to static external field and electric interference. An experimentally implemented SQUID sensor with an integrated input coil with a sensitivity of 0.26 μA/Ф₀ exhibits an intrinsic noise with respect to magnetic flux of less than \(5\mu {\Phi _0}/\sqrt {Hz} \). A system for encapsulation of sensors is developed for applications in multichannel systems for nondestructive evaluation of materials and alternative diagnostic systems.