Vector Particle-In-Cell (VPIC) Project
VPIC is a general purpose particle-in-cell simulation code for modeling kinetic plasmas in one, two, or three spatial dimensions. It employs a second-order, explicit, leapfrog algorithm to update charged particle positions and velocities in order to solve the relativistic kinetic equation for each species in the plasma, along with a full Maxwell description for the electric and magnetic fields evolved via a second- order finite-difference-time-domain (FDTD) solve. The VPIC code has been optimized for modern computing architectures and uses Message Passing Interface (MPI) calls for multi-node application as well as data parallelism using pthreads. VPIC employs a variety of short-vector, single-instruction-multiple-data (SIMD) intrinsics for high performance and has been designed so that the data structures align with cache boundaries. The current feature set for VPIC includes a flexible input deck format capable of treating a wide variety of problems. These include: the ability to treat electromagnetic materials (scalar and tensor dielectric, conductivity, and diamagnetic material properties); multiple emission models, including user-configurable models; arbitrary, user-configurable boundary conditions for particles and fields; user- definable simulation units; a suite of "standard" diagnostics, as well as user-configurable diagnostics; a Monte-Carlo treatment of collisional processes capable of treating binary and unary collisions and secondary particle generation; and, flexible checkpoint-restart semantics enabling VPIC checkpoint files to be read as input for subsequent simulations. VPIC has a native I/O format that interfaces with the high-performance visualization software Ensight and Paraview. While the common use cases for VPIC employ low-order particles on rectilinear meshes, a framework exists to treat higher-order particles and curvilinear meshes, as well as more advanced field solvers.
Researchers who use the VPIC code for scientific research are asked to cite the papers by Kevin Bowers listed below.
Bowers, K. J., B. J. Albright, B. Bergen, L. Yin, K. J. Barker and D. J. Kerbyson, "0.374 Pflop/s Trillion-Particle Kinetic Modeling of Laser Plasma Interaction on Road-runner," Proc. 2008 ACM/IEEE Conf. Supercomputing (Gordon Bell Prize Finalist Paper). http://dl.acm.org/citation.cfm?id=1413435
K.J. Bowers, B.J. Albright, B. Bergen and T.J.T. Kwan, Ultrahigh performance three-dimensional electromagnetic relativistic kinetic plasma simulation, Phys. Plasmas 15, 055703 (2008); http://dx.doi.org/10.1063/1.2840133
K.J. Bowers, B.J. Albright, L. Yin, W. Daughton, V. Roytershteyn, B. Bergen and T.J.T Kwan, Advances in petascale kinetic simulations with VPIC and Roadrunner, Journal of Physics: Conference Series 180, 012055, 2009
Getting the Code
VPIC uses nested submodules. This requires the addition of the --recursive flag when cloning the repository:
% git clone https://github.com/lanl/vpic.git
This command will check out the VPIC source code.
The primary requirement to build VPIC is a C++11 capable compiler and an up-to-date version of MPI.
% cd vpic
VPIC uses the CMake build system. To configure a build, do the following from the top-level source directory:
% mkdir build % cd build
Then call the curses version of CMake:
% ccmake ..
./arch directory also contains various cmake scripts (including specific build options) which can help with building
They can be invoked using something like:
GCC users should ensure the
-fno-strict-aliasing compiler flag is set (as shown in
After configuration, simply type 'make'.
Building an example input deck
After you have successfully built VPIC, you should have an executable in the bin directory called vpic. To build an executable from one of the sample input decks, simply run:
% bin/vpic input_deck
where input_deck is the name of your sample deck. For example, to build the harris input deck in the sample subdirectory (assuming that your build directory is located in the top-level source directory):
% bin/vpic ../sample/harris
Beginners are advised to read the harris deck thoroughly, as it provides many examples of common uses cases.
Command Line Arguments
Note: Historic VPIC users should note that the format of command line arguments was changed in the first open source release. The equals symbol is no longer accepted, and two dashes are mandatory.
In general, command line arguments take the form
--command value, in which two dashes are followed by a keyword, with a space delimiting the command and the value.
The following specific syntax is available to the users:
Threading (per MPI rank) can be enabled using the following syntax:
./binary.Linux --tpp n
Where n specifies the number of threads
mpirun -n 2 ./binary.Linux --tpp 2
To run with VPIC with two threads per MPI rank.
VPIC can restart from a checkpoint dump file, using the following syntax:
./binary.Linux --restore <path to file>
./binary.Linux --restore ./restart/restart0
To restart VPIC using the restart file
Feedback, comments, or issues can be raised through GitHub issues
This software has been approved for open source release and has been assigned LA-CC-15-109.
Copyright (c) 2016, Los Alamos National Security, LLC All rights reserved.
Copyright 2016. Los Alamos National Security, LLC. This software was produced under U.S. Government contract DE-AC52-06NA25396 for Los Alamos National Laboratory (LANL), which is operated by Los Alamos National Security, LLC for the U.S. Department of Energy. The U.S. Government has rights to use, reproduce, and distribute this software. NEITHER THE GOVERNMENT NOR LOS ALAMOS NATIONAL SECURITY, LLC MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY LIABILITY FOR THE USE OF THIS SOFTWARE. If software is modified to produce derivative works, such modified software should be clearly marked, so as not to confuse it with the version available from LANL.
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