Quench Analysis and Improvement of a Semi-Open Split NbTi Superconducting Magnet With Large Inductance

A versatile facility was constructed at Lanzhou University to investigate the field-dependent and mechanical properties of superconducting wires and tapes. In this facility, a high-inductance superconducting magnet cooled by a helium recondensation system is used to generate a 5 T transverse background field. However, the earliest manufactured magnets were burned by high voltage during quenching. Immediate quenching analysis of the damaged magnets was performed using the 3-D OPERA-quench simulation software, and magnets with different structures were optimized using magnetic field and force analysis. The temperature and voltage results during quenching and the peak voltages of several magnet structures under different currents are presented in this article. Finally, the magnets were redesigned and remanufactured, and the magnetic field and force during quenching were optimized. Three quench tests were performed on the optimized structure, and no damage was detected.