An experimental approach for measuring surface potential and second crossover energy in insulators

The goal of this work is to first measure the second crossover energy E2S under stationary electron irradiation (charging conditions) and then to show that the charge balance occurs at this beam energy and not at E2C, the energy deduced from non-charging conditions (short pulse irradiation) as commonly assumed. The experimental procedure is based on simultaneous time dependent measurements of surface potential, leakage and displacement currents. The study is illustrated by the estimate of the real landing energy of primary electrons EL and the second crossover energy E2S for soda-lime glass