Quench Behavior of a Superconducting Dipole Magnet Protected by a Scheme With the Adjustable Quench-Back

The dynamic quench behavior is investigated for a superconducting dipole magnet wound with the six-round-one superconducting cables (six NbTi/Cu wires and one center copper wire), which is protected by a recently developed protection scheme based on the quench-back effect triggered by the center copper wire automatically. The quench transients were measured based on the real-time data acquisition system and also calculated by our previously developed quench model. During the energy discharge of the magnet, the featuring points can be observed on the evolution curves of coil current, induced current, and voltage, which indicates the occurrence of a quench-back. By comparing the results for the cases with and without quench-back effect, the role of the quench-back on the quench protection is analyzed further. Meanwhile, the adjustable resistor can be utilized to control the quench-back effect to satisfy the quench protection requirements.