Research progress of multilayer high gradient insulator technology

In order to satisfy application demand for high performance and miniaturization of pulsed power system, multilayer high gradient insulators (HGI) were designed and fabricated. Using high temperature laminated method; we developed two types of HGI which were fabricated from interleaved layers of brass and polyimide (PI), stainless steel and fluorinated ethylene propylene (FEP). Small samples and large insulation rings of HGI were obtained. The surface state and vacuum out-gassing characteristics of HGI samples were respectively detected. Based on the vacuum experimental platform of nanosecond (10 ns/30 ns) pulse source with Marx generator and single coaxial pulse-forming line, the vacuum surface flashover characteristics of HGI samples were tested. The flashover characteristics of conventional insulation materials were also measured in same test platform. The results show that flashover takes place in the rising period of voltage, and the maximal vacuum flashover field intensity of HGI samples is close to 180 kV/cm.