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([email protected]). 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)([email protected])

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------------           : [email protected]            --------------------||
||---Group------------           : Dr. Gennady Shvets' Group    --------------------||
||---Copyright--------           : (C) 2019 by Tianhong Wang    --------------------||
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