A Quench Detection and Monitoring System for Superconducting Magnets at Fermilab

Abstract

A quench detection system was developed for protecting and monitoring the superconducting (SC) solenoids for the Muon-to-Electron Conversion Experiment (Mu2e) at Fermilab. The quench system was designed for a high level of dependability and long-term continuous operation. It is based on three tiers: Tier-1, FPGA-based Digital Quench Detection (DQD); Tier-2, Analog Quench Detection (AQD); and Tier-3, the quench controls and data management system. The Tier-1 and Tier-2 systems are completely independent and fully redundant. The Tier-3 system is based on National Instruments (NI) cRIO and provides the user interface for quench controls and data management. It is independent from Tiers 1 & 2. The DQD provides both quench detection and quench characterization (monitoring) capability. Both DQD and AQD have built-in high voltage isolation and user programmable gains and attenuations. The DQD and AQD also includes user configured current dependent thresholding and validation times. A 1 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">st</sup> article of the three-tier system was fully implemented on the new Fermilab magnet test stand for the HL-LHC Accelerator Upgrade Project (AUP). It successfully provided quench protection and monitoring (QPM) for a cold superconducting bus test in November 2020. The Mu2e quench detection design has since been implemented for production testing of the AUP magnets. A detailed description of the system along with results from the AUP superconducting bus test will be presented.