Secondary Electron Emission from an Organic Layer with a Surface Charge

Using secondary electron emission (SEE) techniques, conditions for the traveling of electrons near a charged surface were studied. A simple analytical expression was found to relate the effective coefficient of secondary electron emission from the charged surface of an organic liquid layer with the primary-electron current. At low currents, the relationship is close to a root law, the pattern of the dependence does not change with the varying conductivity of the liquid, its thickness, and the charge spot area. This finding suggests that the effective secondary electron emission coefficient and, hence, the conditions of electron motion near a surface charge depend on the only parameter, the current density of incident electrons. According to the estimates of the dielectric permittivity of a liquid, its resistivity, and ion mobility, the effective SEE coefficient at low charging currents is formed in the ohmic mode of current flow through the liquid.