High Sensitivity Magnetometers and Gradiometers Based on Nano-Josephson Junction SQUIDs

In this SBIR Phase I, HYPRES and University of California Riverside will demonstrate the feasibility of low cost, high sensitivity magnetometers and gradiometers utilizing direct-write, high temperature superconducting (HTS) nano-Josephson junction SQUIDs. This fabrication technology is based on direct-write technique using helium focused ion beam (FIB). In this project, we will capitalize on the already achieved results showing SQUIDs with much lower flux noise than typical HTS SQUIDs. We will investigate the effects of non-uniformity and dimension on linearity, dynamic range and noise. We will simulate and design magnetometer and gradiometer circuits integrating a helium ion beam HTS SQUID and a flux concentrator to substantially increase sensitivity. Designs comprising both planar washer type direct-inject and multilayer SQUID input coils will be simulated, designed and evaluated. In Phase II, we plan to develop a compact, portable prototype magnetometers and gradiometers . These sensors will be characterized in a flux-locked loop to determine their sensitivity, bandwidth and dynamic range. Devices will be operated in a micro-dewar and/or on compact cryocoolers to determine practical size and weight requirements, noise properties and other capabilities. In Phase III, we will produce and market magnetometers and gradiometers for biomedical and non-destructive evaluation instrumentation.