WinGraphics: An Optimized Windowing Environment for Interactive Real-Time Simulations

We have developed a customized windowing environment, Win Graphics, which provides particle simulation codes with an interactive user interface. The environment supports real-time animation of the simulation, displaying multiple diagnostics as they evolve in time. In addition, keyboard and printer (PostScript and dot matrix) support is provided. This paper describes this environment

Progress in Parallelizing XOOPIC

X11-based Unix computers) is presently a serial 2d 3v particle-in-cell plasma simulation. This effort focuses on using parallel and distributed processing to optimize the simulation for large problems. The benefits include increased capacity for memory intensive problems, and improved performance for processor-intensive problems. The MPI library enables the parallel version to be easily ported to massively parallel, SMP, and distributed computers. The philosophy employed here is to spatially decompose the system into computational regions separated by “virtual boundaries”, objects which contain the local data and algorithms to perform the local field solve and particle communication between regions. This implementation reduces the impact of the parallel extension on the balance of the code. Specific implementation details such as the hiding of communication latency behind local computation will also be discussed, as well as code features and capabilities. 1 GOALS FOR PARALLEL XOOPIC XOOPIC has been successful as a single-processor code, and is able to simulate many interesting devices including relativistic klystron oscillators, electron guns, DC discharges with gas chemistry, plasma display panel cells, and highly relativistic beams in accelerators. However, particle-in-cell simulations are very computationally intensive, and on a single processor, some problems may take months to complete. The goals, therefore, for parallel XOOPIC are: Reduce run-times for large, complex simulations from weeks to days. Distribute memory demands across machines, allowing larger simulations than possible otherwise. Cross platform portability (networks of workstations, massively parallel machines, and SMP machines). Identical usage and feature set for parallel and nonparallel versions of XOOPIC, and largely shared source code. Complete source code availability to the general public

S-PARMOS - a method for simulating single charged particle motion in external magnetic and electric fields

In this paper we present a new software package for computational simulation of single particle motion in the presence of static external electric and magnetic fields. This seemingly simple problem is in fact very complicated one. Namely, while analytic formulations of this problem are unambiguous, it is very difficult to predict even qualitatively a charged particle trajectory for an arbitrary combination of field parameters, except in simplified cases. Instead, one might perform a single particle motion simulation. Our software package represents a unique tool for this problem. A special new feature of our approach is constructing the instant Larmor Center Trajectory. For the case of slowly changing fields, the Larmor center trajectory reduces to the less general guiding center trajectory approximation. The possibilities for further investigating these two approaches by using our software might be of great interest for both educational and engineering purposes, especially in the areas of gaseous electronics and laboratory, fusion and space plasmas

Similarity-based scaling networks for capacitive radio frequency discharge plasmas

We demonstrate similarity-based scaling networks for capacitive radio frequency (RF) plasmas, which extensively correlate discharge characteristics under varied conditions, incorporating the transition from original to similarity states. Based on fully kinetic particle-in-cell simulations, similar RF discharges in argon are demonstrated with three external control parameters (gas pressure, gap distance, and driving frequency) simultaneously tuned. A complete set of scaling pathways regarding fundamental discharge parameters is obtained, from which each plasma state finds its neighboring node with only one control parameter tuned. The results from this study provide a promising strategy for plasma multi-parameter mapping, enabling effective cross-comparisons, prediction, and manipulation of RF discharge plasmas

Modeling beam-driven and laser-driven plasma Wakefield accelerators with XOOPIC

We present 2-D particle-in-cell simulations of both beam-driven and laser-driven plasma wakefield accelerators, using the object-oriented code XOOPIC, which is time explicit, fully electromagnetic, and capable of running on massively parallel supercomputers. Simulations of laser-driven wakefields with low ({approximately} 10{sup 16} W/cm{sup 2}) and high ({approximately} 10{sup 18} W/cm{sup 2}) peak intensity laser pulses are conducted in slab geometry, showing agreement with theory. Simulations of the E-157 beam wakefield experiment at the Stanford Linear Accelerator Center, in which a 30 GeV electron beam passes through 1 m of preionized lithium plasma, are conducted in cylindrical geometry, obtaining good agreement with previous work. We briefly describe some of the more significant modifications to XOOPIC required by this work, and summarize the issues relevant to modeling electron-neutral collisions in a particle-in-cell code