It is well known that when corona discharge takes place, the discharge device produces a wind.
The wind is a flow of electrically neutral gas particles, created when they collide with ionic particles drifting along the electric field — thus it is called “corona wind” or “ion wind” though it consists of electrically neutral particles.
Now, we have found that corona wind exerts a great influence upon the properties of zinc oxide-resin layer, ie., the corona wind (1) quickens recovery of memory effect in zinc oxide-resin layer, (2) reduces the sensitivity of the layer when exposed to light, and (3) deteriorates the layer.
As the results, we came to a conclusion that, as regards the phenomena (1) and (2), corona wind comprises some species which have fairly large capture cross-sections for free electrons compared with that of molecular oxygen. The deterioration (3) is resulting from the chemical action by ozone molecules in corona wind.

View full abstract

The Q-V characteristic curves of a ZnO-binder layer obtained from the measurement with an ordinary turn-table equipment are greatly dependent on the intensity of corona charger current. This is because of the leakage current through the layer during the intermittent charging by corona current. In this paper, some experiments and analyses are reported on the above phenomenon and the theory and mechanism of corona charging.
The V-I characteristic curve of corona charger can be obtained from the measurement of corona current flowing to a metal plate having various values of bias voltage. It is proved that a corona charger can be expressed neary by a constant current source Io having a parallel internal conductance G₀.
The V-I characteristic curves of ZnO-binder layers can be obtained from the measurement of saturation surface voltage of the sample for various values of corona current. These curves are generally composed of three ranges; increasing current range, saturation current range and avalanche or secondary corona range.
The process and mechanism of corona charging can be understood clearly by the utilization of these two V-I curves of charger and sample, and the saturation state in corona charging is given by the cross-point of these curves. Detailed discussions on the secondary corona, and current waveform are also given.
The true Q-V curves of samples were obtained by the exclusion of leakage charge component from the measured values of Q. The values of dielectric constant and donor density can be determined more correctly from such a corrected Q-V curve than those from original Q-V curve.

View full abstract