Estimation of pulse electric strength of vacuum insulation

Computational modeling of emitter heating by thermo field emission current has been used for the estimation of electric strength of vacuum insulation. The distribution of temperature for tungsten, molybdenum, copper, iron and aluminum emitters has been received upon influence of rectangular and oblique-angled voltage pulses in the range of electric field intensity from 6.6times10⁹ V/m up to 1.4times10¹⁰ V/m. It is shown that for square voltage pulse the breakdown delay time decreases on nine orders of magnitude from 5times10^-3 s down to 10^-12 s with twice growth of electric field intensity from 6.6times10⁹ V/m up to 1.4times10¹⁰ V/m. For the conditioning of electrodes by pulses with duration equal to breakdown delay time, t_p=t_d, the electric strength increases on three orders of magnitude from 10⁷ V/m to 10¹⁰ V/m at the decrease of duration on seven orders from 10^-4 s to 10^-11 s.