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Breakdowns generated with pulsed DC systems between large and fixed Cu electrodes are typically highly localized near the edge of the electrodes. The effect is especially strong on BDs which are generated after the electrode has been conditioned, i.e. when the electric field is near the maximum level. Understanding the reason for this phenomenon can be a key factor in hindering the breakdown rate on a given voltage.
Recent studies hint that the effect is related to the power flow across the electrode surface. Between the contact surfaces of the anode and the cathode, the power travelling from the perimeter to the center is at its highest near the edges, and slightly decreases as it reaches the center point. Limiting the magnitude of this power flow promises to also limit the BD creation.
A straightforward solution to the problem is to consume the power in high-power resistors, inserted in series in between the pulse generator and the anode. The first results show an 18 % increase in the average breakdown field after adding a 5.7 kΩ resistor in the system.