Superconducting digital logic using niobium and operating at 4 K is a breakthrough technology with the potential to use 100x less energy than conventional CMOS. This technology has applications in supercomputing, artificial intelligence, and qubit control and readout. Because the information carrier for these circuits is the magnetic flux quantum, they are highly susceptible to their local magnetic environment, particularly to spurious fluxons penetrating ground planes. The primary goal of this project is to utilize a scanning SQUID microscope (SSM) to image active superconducting circuits. This research will help enable more robust flux mitigation techniques such as “moats,” drive the investigation of new materials, and facilitate failure analysis on novel computing architectures. Major tasks will include operating the SSM, developing and improving control hardware and software, enhancing overall microscope performance, and potentially designing and fabricating new sensor topologies utilizing the state-of-the-art NIST cleanroom facilities.