Continuous Diagnostics for Powered Superconducting Circuits

Monitoring the electrical properties of superconducting devices in their unpowered state has proven essential for commissioning and fault diagnosis during LHC machine operation. Furthermore, continuous diagnostics of powered superconducting circuits in an operational or test environment has the potential to further improve the understanding of existing and possibly ageing facilities. In this paper, we demonstrate that the injection of a very low power and arbitrary stimulus allows continuous monitoring of the electrical properties of a superconducting magnet through all phases of powering. We compare the performance of this novel measurement system in three different states of a superconducting magnet: unpowered, during current ramping, and at a steady operating current. In addition, we compare the new method with the currently used diagnostics of the LHC superconducting magnets for the unpowered devices. Our results indicate that the presented method provides comparable results to the reference system, while allowing continuous probing of the energized superconducting device over extended periods of time.