On the Features of Ambipolar Plasma Diffusion of a Spark Discharge Developing over the Surface of a Dielectric in a Vacuum

In this work, plasma separation into discrete clumps flying perpendicular to the surface of the dielectric was observed at the leading edge of a plasma flare in a vacuum spark discharge along the surface of the dielectric. It is shown that this is the result of spatial separation of the ionic component by the multiplicity of the ion charge. It can be caused both by the acceleration of ions in the potential well of the virtual cathode, which occurs at the front of the cathode flare of a vacuum discharge, and, additionally, by the nature of ambipolar plasma diffusion for this type of spark discharge.