Simulation of Gas-Filled Diodes With the VORPAL Code

摘要

Researchers are interested in rapid switching high-current diodes for applications including accelerators, microwave sources, and flat panel displays. Gas-filled diodes, such as the pseudospark, are one class of candidates for such high-current applications. To yield a better understanding of their operation, numerical simulations of these devices must include a number of physical processes: gas ionization, secondary electron emission and ion-induced electron emission, and radiation. We are enhancing the VORPAL code to model these physical effects, and we present here electromagnetic particle- in-cell (PIC) simulation results for a generic one-dimensional diode. These simulations include models of some of the processes mentioned above, as well as the effects of the self-consistent electro-magnetic fields of the particle beams. We discuss the numerical models used, including techniques to allow users to use these models from a variety of languages, including Java and C++. We examine the case of the planar diode for a variety of conditions and discuss the several physical regimes obtained in terms of analytical models. This study provides an excellent test-bed for verification and validation of both numerical and physical models.