In the manuscript, as a result of comparing experimental and calculated kerrograms, it is shown that during electro-optical measurements in nitrobenzene using the Kerr effect, a strong electric field and absorption of radiation from a probing laser affect the properties of the medium under study. An estimate of such influence on the value of the Kerr constant is made. It is found that in the tip-plane system when using a ruby laser, the Kerr constant near the tip changes. The established dependence of the Kerr constant on the distance to the tip made it possible to obtain a calculated kerrogram that coincides with the experimental one. Thus, it is shown that the measuring instruments can influence the results obtained, that is, under certain conditions, the electro-optical research method is invasive. This fact should be taken into account when processing experimental kerrograms.

In this paper, we continue the analysis of electrooptical studies of the prebreakdown stage in water in the submicrosecond range. We consider a cathode streamer developing in a system of the spherical electrodes. Computer simulation of electric showed that at a constant e = 80, the field strength at the head of the cathode streamer should not exceed E = 1.9 MV/cm. Taking into account the nonlinearity of the permittivity e = e(E) made it possible to estimate this field strength as E ~ 2.4-3.1 MV/cm. It is shown that even with some excess of the strength over the threshold value (ES ~ 3 MV/cm), at which the state of dipole saturation is possible; its consideration does not lead to a noticeable change in the result. Thus, a significant decrease in the field strength near the cathode streamer compared to the anode streamer was confirmed.

The paper deals with the processing and analysis of the results of electro-optical studies of the pre-breakdown stage of an electric discharge in water using the Kerr effect. For this, the first chronogram was selected, obtained in the process of electro-optical chronographic research of water breakdown. In this work, it was possible to explain not only the features of the chronogram but also to obtain an estimate of the intensity of the appearance of the anode streamer in water E ~ 40-50 MV/cm. Using the method of computer simulation in the point-plane system near the anode point, the distributions of the electric field strength and the phase difference were constructed. The calculations were carried out both at a constant relative permittivity and its nonlinear dependence on the electric field strength. It turned out that dipole saturation is observed near the tip. As a result, the Kerr bands become denser and, at a spatial resolution of the recording equipment of 30 μm, in the pre-measuring zone, they are not recorded on the chronogram.