Investigation of 2-dimensional charge distribution on dielectric surface in vacuum by real-time measurement technique

For the establishment of the vacuum insulation technique, the electrical insulation characteristics under the existence of the solid insulator need to be given attention. In particular, a study of a charging mechanism on the solid surface in vacuum is very important. For this reason, we measured a 2-dimensional surface charge distribution using a real-time measurement technique. Under electron beam irradiation to the dielectric surface, we measured the time-transition of surface charge accumulation by electrostatic probes. By varying the electron beam current and the beam energy, we investigated the dependence of such parameters on the charging process. From the measurement results, we clarified that such a measurement technique allowed us to obtain the time varying 2D charging characteristics, which resulted in the clarification of the charging mechanism caused by electron irradiation in vacuum.