Quench Propagation in Helium-Gas-Cooled MgB₂Cables

Abstract

The Superconducting Link project at CERN aims at developing helium-gas-cooled high-current electrical transfer lines for the powering of the superconducting magnets, which are being developed in the framework of the High-Luminosity upgrade of the Large Hadron Collider. A candidate conductor for the cables is magnesium diboride (MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) round wire operated at temperatures of up to 25 K. One of the most important factors to be taken into account during the design phase is quench protection. In this work, we investigate the quench behavior of high-current cables made of MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> . The wires were produced by Columbus Superconductors. The cables are operated in the Superconducting Link Test Station at CERN, which are cooled by helium gas at temperatures between 10 and 30 K. The propagation of the quench front is monitored by means of voltage and temperature sensors installed on the cables. Results of the measurements are compared to numerical simulations, in order to validate the models and quantify the parameters related to quench propagation and protection. The ultimate goal is to devise a quench protection strategy suitable for the safe and reliable operation of the Superconducting Link circuits.