Analysis of the PTS vacuum insulator stack

The paper discussed the relationship between the structure of VIS, especially the thickness of single insulator ring, and working performances of VIS. Utilized combined analysis method with circuit simulation, MFI criterion calculation and flashover probability analysis, obtained the effects of MFI on effective pulse width t_eff and on flashover probability F(t) of whole stack. The t_eff will decrease and the curve of F(t) will move rightward if MFI criterion is considered. The calculation results of flashover probability on ±20 percent change of thickness of single ring are given. The curve of F(t) will move leftward if the thickness of level D decrease 20 percent. So there is possibility of compact design of the PTS VIS, in other words, the original designed VIS can working on higher voltage with same flashover probability level. In designing of z-pinch device with higher current, the MFI criterion must be considered to increase the vacuum-insulator power flow density.