Design and 3D printing of porous cavity insulation structure for ultra‐high electrical withstanding capability

Vacuum-dielectric interface is the most vulnerable part of vacuum insulation systems where surface electrical breakdown prone to happen, hence severely restricts development advanced electro-vacuum devices with large capacity and its miniaturisation. Generally, a direct effective way improve alleviate initiation multipactor phenomena. Inspired by this approach, authors report 3D-printed structure designed millimetre-scale cavity covered periodic through-pore array via stereolithography, exhibiting remarkable suppression flashover threshold improvement, well outperforming conventional mitigation strategies. Experiments simulations demonstrate that electrons in region pass through-pores are unlikely escape from cavity, no longer participate above-surface process, eventually threshold. The proposed approach provides new inspiration for design insulators featuring ultra-high withstanding capability brings up insight into pertinent industrial applications.