Charging characteristics on dielectric surface by different charging process in vacuum

Abstract

This paper describes the charging characteristics on a dielectric surface in vacuum by different types of charging process; electron irradiation by electron beam and field emission by triple junction under negative dc high voltage ap pl i c a t i on. We measured 2-d i men s ional 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 triple junction, it was an acute distribution around the triple junction. Moreover, we quantitatively investigated the difference of the 2-dimensional charging distribution using some shape parameters between above mentioned two charging processes. In addition, we examined the time decay characteristics of the surface potential on the dielectrics in vacuum.