VSim

Simulations can be set up in the VSimComposer setup panel. Shapes can be imported or constructed, materials can be assigned to shapes, fields, and particles can be added, and algorithms can be chosen. VSimComposer then writes out an input file suitable for use by the Vorpal computational engine. The input file can also be written directly. Here, the user has complete control over the physical quantities to include in the simulation, including low-level control over algorithms and solvers. The user can specify the dynamics of the particles as fully relativistic, non-relativistic, unmagnetized, or other. Additional collisions between electrons, ions, and neutral gases (neutral gases being represented by either fluids or particles) are available in the input file, including self-splitting and self-combining operations. Field ionization can also be included. Advanced surface interactions can be modeled, including user-defined secondary electron emission, sputtering, and surface charging. Parallel decompositioning can also be specified manually for high performance applications. == Engine execution ==

VSim can be run from its VSimComposer GUI interface or invoked from the command line. The parallel version of VSim runs on systems that support the Message Passing Interface (MPI). Input to VSim is made via XML-like files used to create simulation objects. A Python-based macro-preprocessor, txpp.py, can be used to generate input files allowing users to set up their simulations with math functions, variable substitutions, macros, and loops. == Data analysis ==

Generated data can be analyzed using any of the built-in analyzers, or users can write their own analyzers in any language. Built-in analyzers output data in VizSchema form for immediate visualization in the VSimComposer visualization pane. For analyzers written in Python, VSim provides the VsH5 package, which facilitates writing output in VizSchema. == Visualization ==

Vorpal output files can be visualized within VSimComposer. Plots include those for particle data, field data, and simulation geometry, with line-outs for inspecting critical variations. The visualization within VSimComposer is accomplished by embedding the powerful VisIt tool, which users can download for more specific visualizations. Use of the VsH5 package along with popular Python tools like matplotlib allows creation of high-quality publication ready plots. == References ==