Thermo-hydraulic Quench Back in a Copper CICC Coil cooled by He II

The MADMAX project aims at detecting axion dark matter in the mass range of 100 μeV. To do so, a dipole detector magnet producing 100 T²m² is needed. In the framework of an innovation partnership with the Max Planck Institute, CEA Paris-Saclay designed this large-scale magnet producing 9 T in a 1.35 m bore. The magnet is made of a cable in-conduit conductor (CICC), operating at 1.8 K. One of the main challenges of this novel design is to guarantee the magnet safety towards quench management. In order to validate the magnet and conductor designs, a mock-up coil with a quench behavior scalable to MADMAX was designed, manufactured and cold tested. The paper gives an overview of the main guidelines followed to design the prototype fully representative of the MADMAX quench behavior. The experimental facility, instrumentation and protocol are presented. The main experimental results are given and extensively analyzed with empirical, analytical and numerical approaches. This paper presents the first experimental observation of the existence of the THQB phenomena in stagnant superfluid helium.