Upgrading of PIC Codes for HPM Tube Design

The primary objective of this proposal is to develop an understanding from first principles of the macroscopic particle force equation arising from the microscopic particle and field interaction dynamics and to incorporate those effects in a self-consistent state-space (rate equation) PIC calculation. Effective current and charge density time-domain equation models will be developed from this generalized Lorentz force model. The project will develop the numerical modeling techniques that will allow the self-consistent coupling of the particle motions and the evolution of the electromagnetic fields in the presence of complex electromagnetic scatterers. The resulting simulators will be applied to a variety of HPM source configurations.Specific tasks will include:(1) developing a generalized Lorentz force equation and its equivalent current and charge rate equations directly in the space-time domain;(2) developing the plc tools and techniques for modeling the interaction of intense electromagnetic fields with one and several particles in one and two and three space dimensions and time;(3) applying the resulting simulators to study the generation of microwaves in a HPM source cavity, particularly by predicting any additional microscopically-derived force effects on a large number of charged particles;(4) applying the resulting simulators to study a many-particle plasma system typically found in HPM sources.