An oscillation phenomenon in charging/discharging of small solid insulators

An oscillation phenomenon of charging/discharging in insulators is observed using the scanning electron microscope (SEM) mirror-image technique. After implanting electrons in an insulating material, bright rings are observed on the insulator surface in SEM images. Traces of flashover from the rings are also found. These observations suggest that charge is distributed or oscillated in rings. The mechanism of this oscillation behavior is discussed.