Analysis of a forced extinction of a diffuse vacuum arc for digital modelling purposes

The decay time of electron current in the post-arc phase after a forced interruption of a diffuse vacuum arc were measured experimentally. Arc current of amplitude 400 A was switched-off using counter-pulse currents with failing rates from 3 A/μs u to 30 A/μs. The decay process of electron current was observed using a Langmuir probe. The decay times of electrons of mean values from 4.5 μs up to 6 μs were measured Considering the flying times from the contact edge to the probe at current zero, the decay times of electrons can be estimated in the, range from 0, 5 us up to 3 μs. These values are proposed as electron deceleration time in modelling of post-arc phenomena for low voltage vacuum switches.