Abstract
A strange and peculiar phenomenon was found in which pulse discharge inception voltage of a small gap decreased considerably by using an electrode with a dielectric. The dielectric was contact with an edge of the electrode which position was far isolated from the gap.
The discharge inception voltage decreased with increasing permittivity of the dielectric and with reducing distance between the discharge position and the electrode edge with the dielectric. Residual charge on the dielectric was observed after application of high pulse voltage enough to discharge the gap. Potential of the dielectric was adjusted by resistive connection between conductive paint on the dielectric surface and the electrode, and was shown to influence the discharge inception voltage of the gap. A light shield between the electrode edge with the dielectric and the gap also influenced the discharge inception voltage of the gap definitely.
These phenomena can be explained by pre-ionized self-triggering discharge. A peculiar point is that this electrode has no adjacent third electrode for triggering the discharge. The discharge is concluded to be triggered by UV ray from pre-ionization at a far isolated edge of its own electrode, stress of which is enhanced by adding a dielectric.
