Software for Modeling and Design of Diamond Amplifier Cathodes

The successful operation of the Department of Energy (DOE) next generation X-ray light sources, free electron laser (FEL), and accelerator facilities depends on developing reliable photo- cathodes with long lifetime for production of low emittance, high-brightness, high-average current electron beams. Experiments in the Brookhaven National Lab (BNL) have already demonstrated the potential to generate amplified electron beams with peak current density greater than 400 mA/mm2 and average current density larger than 100 mA/mm2 but the emission of electrons from rough diamond surfaces with negative electron affinity is still to be understood. Physics based simulations of diamond amplifiers can offer valuable insight into their operation, provide guidance to experimental approaches and help their design optimization, however, there are currently no available codes that offer these capabilities. Generation of secondary electrons and charge transport in bulk diamond can now be simulated with the three dimensional, particle-in-cell (PIC) code VORPAL. However, it lacks algorithms for high-fidelity modeling of surface effects and electron emission from diamond amplifier cathodes. We will develop and implement algorithms for accurate modeling, including quantum mechanical effects, of surface physics phenomena and electron emission from diamond with negative electron affinity within VORPAL to enable end-to-end simulations of diamond-amplified photocathodes cou- pled to electron guns. Commercial Applications and Other Benefits: The proposed code for high-fidelity simulations of diamond amplifier cathodes will aid re- searchers in developing electron sources that meet or exceed the desired operational parameters for future DOE facilities. This project will produce commercial quality software, including a state- of-the-art graphical user interface (GUI), and will allow the VORPAL code (already a successful commercial product) to increase its potential for generating further commercial revenue