Simulation studies of the distribution of field-enhancement factors for individual cone emitter

It has been demonstrated by Spindt et al. using simulation method that the field on the cap surface of a cone is constant when the polar angle changed from 0° to 30°. In this work, a three-dimensional simulation method CST was used to investigate the electric field distribution on the same cone. It can be found that the field on the cap surface decreases with the increase of polar angle, and this has good agreement with the theoretical analysis. It can be believed that the difference between the two simulation results should be contributed to the better computer performance and more accurate simulation method today. Therefore, it is essential to reconsider the conclusions obtained by simulation in early days.