Abstract
The pulsed electro-acoustic (PEA) method is widely used to measure the space charge distribution through the thickness of solid dielectric materials. One of the well-known phenomena obtained by space charge measurement is the `packet charge' that is injected from one electrode and travels as a bulk to the other electrode. It has been observed as a bulk charge that moves inside the specimen, using a normal PEA system. We have developed a two-dimensional PEA system that can measure space charge profiles in a section of the specimen. By using this new two-dimensional PEA system, it was revealed that the `packet charge' is not homogeneous, and internal space charge behavior is more complicated than those described for bulk charge.
