Charging solid microparticles in the chamber of the injector of an electrostatic accelerator

Some questions on the theory of charging particles in the charging chamber of an injector are considered. Two mechanisms (contact and contactless) for charging conducting particles in the region of the charging needle of an injector and the processes of charging microparticles by dark currents are considered. The value of the particle charge that is formed upon the occurrence of a microdischarge between the particle surface and the charging needle is evaluated. The results of the experimental study of the injector operation are presented: the plots that describe the dependence of the particle-escape frequency on the voltage at the charging electrode and the particle flow as a function of the diameter of the injector output aperture.