Measurement of electron avalanche current in a point-plane geometry stressed with negative voltage

The measurement of corona discharge currents in simple gaps is very essential in many investigations. Practical measurements have indicated that the associated current pulses have rise times measurable in nanoseconds. As the corona discharge occurs primarily outside the electrodes, it will be of fundamental interest to seek correlation between the basic avalanche process and the measurable current pulse. The intended exercise requires an elaborative full wave solution with a detailed voltage source modeling. As such work in this direction is rather scarce and further most of the available literature is limited to quasi-static approximation. In order address at least partially this lacunae, the present work is taken up. It basically aims to relate the avalanche process to the resulting current pulse in simple needle-plane geometry stressed with negative voltage. The analytical expression, derived in our recent work for the total field due to an isolated avalanche is employed with method of images to calculate the incident field. The induced current is then evaluated by numerically solving the electric field integral equation. Sample cases are considered to show the differences between the actual avalanche current and that measurable in the loop.