Simulating the inception of pulsed discharges around needle electrodes

When a positive voltage pulse is applied to a sharp electrode, an inception cloud can form around the electrode tip. This is an almost spherically expanding ionized region. As recently demonstrated in experiments by S. Chen, L. Heijmans and S. Nijdam, the properties of these inception clouds depend on the gas mixture and on the voltage pulse. We present a 3D particle model to simulate the initial stage of pulsed discharges near needle electrodes. With this model, we investigate how the properties of inception clouds (growth velocity, maximum size, time of destabilization) depend on the gas mixture and voltage pulse, and we compare with the experiments mentioned above.