ac surface discharge on dielectric materials observed by advanced Pockels effect technique

Abstract

Techniques for visualization and quantification of the latent electric charge image on dielectric materials have been developed using Pockels effect of a BSO (Bi12SiO20) single crystal, a charge coupled device camera recording system, and a computer image processing technique. The Pockels device of the BSO single crystal was used as a transducer to transfer the surface charge density to retard the transmitted light beam. The basic principle of advanced electro-optical surface charge measurement is described and typical surface charge distributions of positive and negative discharge streamers produced by an ac (50 Hz) high voltage are demonstrated. The measured surface charge images are shown on a computer monitor as three-dimensional figures.

Imaging electrostatic fingerprints with implications for a forensic timeline

“…By contrast the method proposed in this paper relies on contact electrification, which is widely accepted to be almost independent of both the subject and the transfer method [10]. The decay of the resulting surface charge is a function of the physical properties of the material and the environmental conditions prevailing [11]. Clearly the material may easily be characterised using a known test charge, leaving The electrical charge deposited by contact electrification due to a finger touching a thin insulating surface is imaged using an electric field microscopy system.…”

Progress in Japan of electrical field measurement technology for liquid dielectrics

“…For example, the Pockels effect has been used to measure the electric field in space [19, 201, to measure high voltage [21], and to observe surface discharge patterns [22,23,24]; the Kerr effect has been used to measure the electric field inside liquid dielectrics as described in this paper; and the photoelastic effect has been used to measure residual mechanical stress distribution in the plastic plate of a compact disk. By introducing recently advanced electronic techniques, new fields of application of dielectric anisotropy are expected to be added to engineering measurement.…”

Gap-dependent arrangements of dielectric barrier discharges in open air

“…10,11,14,15 It is generally believed that the locations of the filamentary discharges are affected by the memory effect of the surface charges. 10,[16][17][18] Although the localized discharges do not synchronously appear and are not real particles as in granular systems and in dusty plasma systems, the localized pattern shows similar properties such as the defect pairs and the moving trajectories.…”