Analysis of the Self-Protection Characteristics of a 1.5T Bitter-Like HTS Magnet Operated at 65K

We present a conceptual configuration of a high-temperature superconducting (HTS) magnet made from REBCO (Re=Rare Earth, B=Barium, C=Copper, O=Oxide) annular plates, called a Bitter-like HTS magnet, which can operate in persistent current mode without joint resistance and can be excited by a flux pump and without current leads and a persistent power supply. An REBCO annular magnet which can generate 1.5 T corresponding to the operating current density 80% of critical current density of the magnet at an operating temperature of 65 K is conceptually designed. Then the thermal stability of the magnet is numerically simulated by Comsol software. When a piece of REBCO annular plate quenches, the maximum released energy is its stored energy because each REBCO annular plate in the Bitter-like magnet is in parallel. To calculate the stored energy in the REBCO annular plate, the inductance of every annular plate, including self-inductance and mutual inductance, is calculated. Compared with the minimum quench energy (MQE) and stored energy in one REBCO annular plate, the stored energy in one REBCO annular plate is always smaller than the MQE, and the REBCO annular plate will not be damaged even though the stored energy in the REBCO annular plate is fully released, which indicates that this 1.5 T Bitter-like magnet has the property of self-protection.