No abstract

Change in time for the shape of the discharge current pulses of the pulsed negative corona in oxygen with cop-per and stainless steel cathodes has been studied for two discharge modes. The change lies in the decrease of the pulse amplitude and duration at half maximum. It is shown that for stainless steel cathodes, the amount of electric charge transferred in one pulse of the discharge current is 15% greater than for copper cathodes. It is also shown that under the maximum load mode, the amount of charge transferred in one pulse of the discharge current is de-creased with time by 10% for both types of cathodes. It is shown that ozone synthesis in the electrode system with copper cathodes is 25% more efficient.

The numerical simulations of negative corona discharge in Trichel pulse mode are carried out with the calculation of evolution of azimuthal perturbations. It is found the azimuthal instability with increment corresponding to avalanche development. This instability is suppressed at the nonlinear stage and does not lead to the process branching. The result is also applicable to the azimuthal instability of the cathode directed streamer, found earlier. The difference in their increments is followed from the difference in courses of the processess, which is discuss.

The numerical simulations of the cathode directed streamer propagation in the discharge gap, with the streamer going out to cathode, are carried out. The processes are found, which take place near anode and contribute to the formation of the first of two maxima of total current time dependence. The factors are considered, which determine the propagation of the ionization process at the final stage, when the streamer approaches the cathode, and the ionization wave is propagating along the cathode surface.

The influence of combined supply voltage parameters (bias voltage and voltage pulse amplitude) on efficiency of ozone synthesis in the negative pulsed corona discharge in oxygen was obtained. Pulse overvoltage led to intensification of discharge processes. Bias voltage applied during the discharge channel relaxation essentially increased the efficiency of ozone synthesis. It was established that the “optimal” bias voltage which provides maximum ozone generation doesn’t depend on voltage pulse amplitude, but depends on input oxygen concentration and generated ozone concentration.