Pulsed Electric Strength of Vacuum Gaps

To plot unified dependences of breakdown voltage and electric strength on gap spacing, known experimental data for breakdown delay time in vacuum are analyzed and generalized. Analysis and generalization are realized from positions of the cathode- initiated breakdown. The data, which correspond to optimal modes of conditioning and are received at different experimental conditions for pulses of different shapes and durations in electric fields with a different degree of heterogeneity, are resulted in unified conditions for uniform field and rectangular pulse with given duration. Dependences of breakdown voltage U_br(d) and electric strength E_0br(d) on gap spacing d for copper electrodes in range 3times10^-3 les d les 2times10² mm are plotted. At plotting curves U_br(d) and E_0br(d), the total voltage effect is considered. At pulses duration of t_p = 0.5 mus, the breakdown voltage makes up 2.5 kV for d = 3 mum and rises with interelectrode distance by three orders of magnitude up to 5 MV for d = 20 cm. The electric strength increases ~ 30 times from 2.5times10⁷ V/m for d = 20 cm up to 7.5 times 10⁸ V/m for d = 3 mum with decrease in gap spacing.