Thermal-electrical coupling analysis based on solid-liquid phase transition theory of single-turn coil

Single-turn coil (STC) is a destructive pulse magnet aiming at a 100-300 T ultra-high magnetic field. A thermal-electrical coupling model, in which the solid-liquid phase transition process is considered, is proposed. The effects of solid-liquid phase transition on pressure, temperature, and electrical conductivity are investigated. The results show that the compressed and stretched regions coexist simultaneously, and the distribution of both regions changes with time during discharging. Moreover, the region with the highest current density is inside the conductor, since the phase transition reduces the electrical conductivity of the region near the inner surface of STCs. By comparison, the simulation results are highly consistent with the measured data, and the necessity of considering the phase transition process is validated. The results obtained in this work are helpful for understanding the thermodynamic process of STCs during discharge.