When a quench occurs in a high field no-insulation (NI) high temperature superconductor (HTS) magnet that consists of a stack of double-pancake (DP) coils, a large amount of current is often induced in an NI DP coil that is electromagnetically coupled with neighbor DP coils. Depending on the strength of external magnetic field, the large induced current leads to an excessive magnetic stress and occasionally damages the magnet. In this paper, we propose a new quench protection concept to reduce the amount of induced current in an NI HTS magnet. The key idea is to use resistive copper within the magnet windings in order to absorb a portion of electromagnetic energy that is initially stored in the magnet before the quench. We tentatively name these resistive coils or plates as a “magnetic dam”, as they may slow down the electromagnetic quench propagation speed among the NI DP coils, which may be beneficial to avoid the mechanical damage by the large over-current.
This work was supported by Samsung Research Funding & Incubation Center of Samsung Electronics under Project Number SRFC-IT1801-09.