Abstract: After interruption of a high-frequency (hf) current by a vacuum arc, two distinct types of reignition can be observed. The first type follows immediately after interruption, the second type tends to allow a currentless pause of a few tenths of a microsecond. The post-arc current that flows after hf-current interruption has been measured and has a peak of several A and a decay time of a several hundreds of ns. A dynamic sheath model for the decaying plasma after hf current interruption has been used successfully to model the measured post-arc current waveshapes. The first type of reignition may be attributed to thermal stress during the period in which no ion sheath has been formed yet, the second type to high electric fields, either due to the ion sheath, or due to the TRV, the weight of each depending on gaplength and di/dt.!7
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