Features of spherical particle dynamics near a plane electrode of vacuum gap in an increasing electric field

The paper reports on numerical simulation of dynamics of a spherical particle escaped from one of the electrodes of a vacuum gap at an increasing electric field. It is shown that at a sufficiently high rate of rise of the electric field strength, the particle can be held for a time at the electrode by electrostatic force. During this time, the particle makes small jumps which involve spikes of local field strength (up to 3 - 4 GV/m) and field emission current in the space between the particle and the electrode. The possibility of activation of emission sites and initiation of vacuum breakdown on particle detachment from the electrode is discussed.