VORPAL is a computational plasma framework that can predict the dynamics of electromagnetic systems, plasmas, and rarefied as well as dense gases. VORPAL is used for modeling vacuum electronics, photonic devices, laser wake-field acceleration, plasma thrusters, fusion plasmas, and multipactor effects in Superconducting RF cavities. Originally developed by the Plasma and Beam Physics Group at the University of Colorado, VORPAL is currently developed and marketed by Tech-X Corporation.
VORPAL is highly flexible. It is arbitrary dimensional, meaning that it can be run in one, two, or three dimensions. Plasmas in VORPAL can be represented by a fluid or kinetically using the PIC algorithm (with a continuum/Vlasov representation in development). It can be run in full electromagnetic mode, using the FDTD algorithm, or with an electrostatically computed field. The fields and particles can be bounded by arbitrarily shaped structures, including conductors, particle absorbers, reflectors, and many more. The computational domain can be periodic or mimic boundaries at infinity via PML (Perfectly Matched Layer) boundary conditions.
The implementations for the basic collisional processes are provided by the TxPhysics cross-platform library of computational modules. These include models for impact ionization of neutral gases by electrons and ions and field-induced tunneling ionization of atoms. VORPAL can also, through use of TxPhysics, include the ion range and stopping power in solids, ion-induced electron yield from solids, and secondary electron yields.
VORPAL can be run from its GUI interface or from the command line. The parallel version of VORPAL runs on systems that support the Message Passing Interface (MPI). Input to VORPAL is made via XML-like files used to create simulation objects. A Python macro-preprocessor, txpp.py, can be used to generate input files allowing users to set up their simulations with math functions, variable substitutions, and macros.
VORPAL outputs data in HDF5 (Hierarchical Data Format) that is VizSchema compliant. VORPAL output files can be viewed via VorpalView, the GUI tool for visualizing plots of particle data, field data, and simulation geometry that is included in VORPAL. VorpalView is written in IDL and runs on the free IDL virtual machine (versions 7.0.3 or greater). VORPAL output files may also be viewed with other visualization tools such as VisIt.