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arXiv · 1208.3998

Inception and propagation of positive streamers in high-purity nitrogen: effects of the voltage rise-rate

T. T. J. Clevis·S Nijdam·U Ebert
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Abstract

Controlling streamer morphology is important for numerous applications. Up to now, the effect of the voltage rise rate was only studied across a wide range. Here we show that even slight variations in the voltage rise can have significant effects. We have studied positive streamer discharges in a 16 cm point-plane gap in high-purity nitrogen 6.0, created by 25 kV pulses with a duration of 130 ns. The voltage rise varies by a rise rate from 1.9 kV/ns to 2.7 kV/ns and by the first peak voltage of 22 to 28 kV. A structural link is found between smaller discharges with a larger inception cloud caused by a faster rising voltage. This relation is explained by the greater stability of the inception cloud due to a faster voltage rise, causing a delay in the destabilisation. Time-resolved measurements show that the inception cloud propagates slower than an earlier destabilised, more filamentary discharge. This explains that the discharge with a faster rising voltage pulse ends up to be shorter. Furthermore, the effect of remaining background ionisation in a pulse sequence has been studied, showing that channel thickness and branching rate are locally affected, depending on the covered volume of the previous discharge.

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T. T. J. Clevis, S Nijdam, U Ebert. 2012-08-20. Inception and propagation of positive streamers in high-purity nitrogen: effects of the voltage rise-rate. https://doi.org/10.1088/0022-3727%2F46%2F4%2F045202

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