Comparison of candidate secondary electron emission materials

Secondary electron emission (SEE) yields obtained with empirical models deviate significantly from experiment. Therefore they cannot be used to predict the SEE data for various materials. The angular dependencies of SEE in empirical models are also drastically different and inconvenient for comparison. SEE coefficients were calculated by a theoretical method that uses Monte Carlo simulation, empirical theories, and close comparison to experiment, in order to parameterize the SEE yields of highly emissive materials. We have successfully applied this method to bulk Al2O3, a highly emissive material for micro-channel plates, as well as to thinly deposited films of Al2O3. The simulation results will be used in the selection of an emissive material, and if the emission yield of the material is small, as a resistive material for the deposition and characterization experiments that will be conducted by a large-area fast detector project at Argonne National Laboratory.