CLASSE Seminar - Dimitre Dimitrov

Thursday, March 1 at 1:00pm to 2:00pm

Wilson Synchrotron Lab, 3rd Floor Wilson Commons

The CLASSE Seminar is pleased to sponsor the upcoming talk by Dimitre Dimitrov of Tech-X

Title: "Modeling and Simulations of Charge Carrier Effects in Diamond and GaAs for Cathode Applications"

Abstract: High-fidelity modeling and simulations of electron emission physics are needed to better understand and address cathode-related issues. I will review work we have done to develop and implement algorithms in the VORPAL three-dimensional particle-in-cell code for modeling charge gain, transport, and emission from diamon-amplified cathodes. Emission of electrons in diamond experiments based on the promising diamond-amplifier concept was recently demonstrated. However, these emission experiments indicate that surface effects should be understood in detail to build cathodes with optimal properties. Transmission mode experiments have shown the potential to realize over two orders of magnitude charge amplification. We have made progress in understanding secondary electron generation and charge transport in diamond transmission-mode experiments with models we implemented in VORPAL. We have started to investigate algorithms for surface effects (band bending and electron affinity), charge trapping, and electron emission from diamond. I will present and discuss results from 3D VORPAL diamond-vacuum simulations with the integrated capabilities on generating electrons and holes, charge transport, and then emission of electrons from diamond into vacuum. Recently, we have also started to add capabilities for simulation of charge transport in a three-band GaAs. Results from GaAs simulations with these capabilities will also be presented and their relevance to cathode-related experiments will be discussed.