Architecture and computing philosophy of the QUICKSILVER, 3D, electromagnetic, particle-in-cell code

Charged-particle simulations in three dimensions are now performed routinely in the Pulsed Power Sciences Directorate at Sandia with the QUICKSILVER suite of codes. QUICKSILVER is a multitasked, finite-difference, three-dimensional, fully relativistic, electromagnetic, particle-in-cell code developed at Sandia. It is targeted for use on current and near-term supercomputers, such as the Cray X-MP/416, which are characterized by large, shared central memories and multiple processors. QUICKSILVER has already been used to simulate ion diodes, magnetically insulated transmission lines, microwave devices, and electron beam propagation. QUICKSILVER is actually a suite of codes; in addition to the main simulation code there are several support codes. The problem geometry is generated with a preprocessor and the simulation results are examined with one or more postprocessors. The MERCURY preprocessor assists the user in defining the mesh, boundary conditions, and other input parameters. The FLASH and AVS postprocessors are used to examine a wide variety of simulation output, including 3D rendering of particle positions, conductor surfaces, and scalar and vector quantities. The PLOTPFF postprocessor displays 2D slices and 1D pencils derived from 3D scalar and vector quantities. Additionally, time histories of various simulation quantities can be examined and manipulated with the IDR postprocessor. Each code in the QUICKSILVER suite may be run on hardware platform for which it is best suited. Currently, QUICKSILVER is run on a Cray X-MP/416, FLASH and AVS on a Stardent 3D graphics workstation, and MERCURY, IDR, and PLOTPFF on a VAX computer. A robust and functional computer network then ties the suite together. All codes in the suite adhere to standards as much as possible in order to ease porting to different hardware platforms