Charging characteristics on dielectric surface by different charging process in vacuum

This paper describes the charging characteristics on a dielectric surface in a vacuum by different types of charging process: electron irradiation by electron beam; and field emission by triple junction under negative DC high voltage application. The authors measured the 2-dimensional distribution of electrostatic charging on the dielectric surface in-situ. Experimental results revealed that the negative charge distribution by the electron beam had a conical shape all over the surface. On the other hand, for the triple junction, it was an acute distribution around the triple junction. Moreover, they quantitatively investigated the difference of the 2-dimensional charging distribution using some shape parameters between above mentioned two charging processes. In addition, the authors examined the time decay characteristics of the surface potential on the dielectrics in vacuum