Multi-Scale Physics Issues in the Development of a Virtual Laboratory for Advanced X-Ray Sources

Abstract

Summary form only given. The state-of-the-art in first principles physics software has greatly advanced in the last few years though the advent of highly efficient, scalable parallel software and ubiquitous Beowulf-class clusters. In the arena of high power microwave and X-ray sources, it is not unusual to simulate multi-dimensional (2- and 3-D), fully electromagnetic situations with fidelity sufficient to fully design experiments on the computer using the particle-in-cell (PIC) framework. Despite these advances, there are a number of situations where dense plasma formation and critical atomic physics issues result in multiple time scales where the simulations are simply too complex to run in a meaningful time period, even with parallel computers. This effort focuses on the potential to couple magneto-hydrodynamics (MHD) and atomic physics software packages together with the PIC framework to alleviate these time-scale issues. We will report on simulations of electron beam emission off moving cathode plasmas, dense anode plasma formation, insulator breakdown, secondary electron production, and anode heating in the context of a bremsstrahlung diode PIC simulation. These calculations show clear evidence of improvement possible through coupling the PIC framework to MHD and atomic physics software as well as potential areas where improvement of the PIC software can bring nearly as much benefit