Development of Advanced Models for 3D Photocathode PIC Simulations

Codes for simulating photocathode electron guns invariably assume the emission of an idealized electron distribution from the cathode, regardless of the particular particle emission model that is implemented. The output of such simulations, a relatively clean and smooth distribution with very little variation as a function of the azimuthal angle, is inconsistent with the highly irregular and asymmetric electron bunches seen in experimental diagnostics. To address this problem, we have implemented a recently proposed theoretical model [1] that takes into account detailed solid-state physics of photocathode materials in the VORPAL particle-in-cell code [2]. Initial results from 3D simulations with this model and future research directions are presented and discussed.