Yasunori Miyoshi

Pulseless Corona in Negative Point to Plane Gap

The pulseless corona of a negative point to a plane gap in air was examined. At high pressures it behaves as a kind of abnormal glow discharge. By increasing the corona current, the reduced current density on the cathode surface increases from 267 µA/(cmTorr)2 at the onset to 490 µA/(cmTorr)2just before the spark breakdown. The gas temperature of the negative glow shows also an increase in the range of 1050~1170 K with increasing corona current. The current distributions on the plane electrode are similar for different values of the gap length. In the space gap near the plane electrode, at the moment of transition is equal to or greater than the electron attachment coefficient. This result can be used as a criterion for the occurrence of a transition from the negative pulseless corona to spark breakdown.

The formation of a positive corona in air

An investigation has been made of the photon pulses and the associated current pulses in the pre-onset stage of a positive point corona in air at atmospheric pressure. The transition from burst pulses to streamer pulses is discussed.

The Statistical Distribution of Sparking Time-Lag

The statistical distribution of the sparking time lag is studied theoretically. Especially the effects of the electrons remaining in the space near the cathode under over voltage to a continuously illuminated gap are discussed in detail.

The statistical distribution of carrier number in electron avalanches in gases

Theoretical investigations are given on the statistical distribution functions of the number of electrons in a series of electron avalanches initiated by a high‐energy particle at an applied voltage below the sparking voltage. The distribution functions are derived for the electron avalanches started by initial electrons generated at the cathode, using the Poisson and geometric distributions for the initial electrons. Furthermore, the distribution function is obtained for the electron avalanches started by a single initial electron generated at any place in a discharge gap.