WAND-PIC

(This is the alpha release of WAND-PIC, some parts are not completely developed and still under testing. Please report an issue if you see errors, and any resulting instability. Thanks!)

Wakefield AcceleratioN and Direct-laser acceleration — Particle in Cell Simulation.

WAND-PIC is a 3D parallel quasi-static particle-in-cell simulation code. Developed by Tianhong Wang in 2019, at Dr. Gennady Shvets’ Group, Cornell University.

You are welcome to clone or download this repository. Please also send an email to the author Tianhong Wang(tw474@cornell.edu). We’d like to keep track of user numbers and affiliations.

Features

• 2D partitioning of the transverse domain.
• Adaptive longitudinal mesh refinement according to the speed of plasma trajectories.
• Advanced quasi-static equations, there is no need of “predictor-corrector” scheme.
• In-house parallel Multigrid Solver. One for all equations.
• Sub-cycling of macro beam particles, captures sophisticated wave-particle resonant interaction.
• Parallel output and reload.

Structure

Prerequisites

• A MPI Library

  impi or mpich

• A Parallel NetCDF Library

  pnetcdf

• A Good Weather.

• A Working Computer and Electricity.

Compiling

A simple & working Makefile is included Makefile. The ‘make’ should work on most machines, and your are welcome to write your own one.

Tested Environment

WAND-PIC has been tested on four different server/supercomputers, from few cores to over 4000 cores, including:

• TACC STAMPEDE2: SKX Nodes [Intel Xeon Platinum 8160 (“Skylake”)]

  intel/18.0.2; impi/18.0.2; pnetcdf/1.11.0

• TACC STAMPEDE2: KNL Nodes [Intel Xeon Phi 7250 (“Knights Landing”)]

  intel/18.0.2; impi/18.0.2; pnetcdf/1.11.0

• TACC LONESTAR5: Nodes [Intel Xeon E5-2690 v3 (“Haswell”)]

  intel/18.0.2; cray_mpich/7.7.3; pnetcdf/1.8.0

• Small Server: Nodes [Intel Xeon(R) E7-4830 v4]

  intel/18.0.2; impi/18.0.2; pnetcdf/1.11.0

(** when running with pnetcdf older than 1.10.0??, parallel output may not work properly. This happens on Lonestar5 occasionally for unknown reasons.)

Benchmarking

Running

Example: running on a server with 36 cores

mpiexec -n 36 ./WAND

Simulation Example

Intense Laser Pulse Propagates in the Tenuous Plasma

Long Electron Beam Propagates in the Tenuous Plasma (Hosing Instability)

Developing

I started to work on this project in early 2019 and I am currently the only author of this project. Due to the lack of workforce and limited energy & time, I may improve and update the code slowly in the future. Hidden bugs are waiting to be found, and many functions/modules need to be added.
This version of WAND-PIC is the first version I finished recently (around July-2019) and it’s already been used in several research. During the development of WAND-PIC, I am trying to keep as less dependency as possible and the pnetcdf is the only lib I use. Some part of the code are still under developing, for example, the Multigrid class, it needs further testing and improving.
Suggestions and feedback are welcome.

Task Lists

• Periodic Boundary Condition (finished, need test and upload)..
• A Reduced, Simplified Radiation Module (Classical)..
• Pipeline in Longitudinal Direction and Load Balance..
• More and Better MG Solver Smoother..
• High-order Pondermotive Potential..
• OpenMP..

Author

• Tianhong Wang (Cornell University)(tw474@cornell.edu)

License

This project is licensed under the MIT License - see the LICENSE.md file for details.

Acknowledgments

• The author of WAND-PIC would like to thank all members in Dr. Gennady Shvets’ Plasma Group at Cornell University.
• Thank Dr. Vladimir N. Khudik for his help in deriving related equations.
• Thank Dr. Roopendra Singh Rajawat for inventing the name “WAND-PIC”.

Reference

About some of the algorithms

About DLA_1; DLA_2

About our group

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||--  (W)akefield (A)cceleration a(n)d (D)LA - (P)article (i)n (C)ell Simulation  --||
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||---Author-----------           : Tianhong Wang                --------------------||
||---Starting---------           : Jan-11-2019                  --------------------||
||---Email------------           : tw474@cornell.edu            --------------------||
||---Group------------           : Dr. Gennady Shvets' Group    --------------------||
||---Copyright--------           : (C) 2019 by Tianhong Wang    --------------------||
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