Electrical Breakdown Characteristics in High-Vacuum Conditions for the Design of Superconducting Coils

In recent years, the utilization of high-temperature superconductors (HTS) in medical devices, such as magnetic resonance imaging (MRI) and particle accelerators for cancer treatment, has seen significant growth. This study focuses on the electrical insulation design of fast-ramping HTS saddle magnets, pivotal in reducing the volume and consequent operational costs of particle accelerators. Generally, these HTS magnets are operated under high-vacuum conditions to deter external heat intrusion and optimize thermal efficiency. However, their intricate geometries can inadvertently result in areas of localized vacuum degradation, undermining their electrical insulation capabilities, especially in environments with pressures less than 0.001 Pa. Further, this research delves into the influence of vacuum degree and insulator surface roughness on the electrical breakdown properties. The focus is…