Merzbild.jl

Merzbild.jl is a Direct Simulation Monte Carlo (DSMC) code written purely in Julia. It provides all the necessary building blocks for building a DSMC simulation, i.e. particle indexing, collisions, file I/O. Combining these blocks together is left up to the user; examples can be found in the simulations directory. It supports variable-weight DSMC simulations and ionized flow simulations, PIC and Stochastic Fokker-Planck capabilities are in development.

The goals are to provide a modular, thoroughly tested, easy-to-read and easy-to-extend code for quick implementation and testing of new ideas.

Brief overview of capabilities

Currently the code supports spatially homogeneous (0D) and 1D uniform grid simulations. The table below lists support for the fixed- and variable-weight versions of the code, with different supported particle merging algorithms listed for the different simulation types.

A more detailed overview of the capabilities is given on the Overview of capabilities page.

The output format is NetCDF4.

Installation

For now, Merzbild.jl needs to be cloned to be run. Once cloned, navigate to the directory, run

julia --project=.

and in the Julia interpreter run

using Pkg; Pkg.resolve(); Pkg.instantiate();

to install the required packages. Running Pkg.test() afterwards will install the test environment dependencies and run the tests.

Usage

Currently, the way to use the code is to

1. clone it
2. create a new file in the simulations directory
3. add include("path/to/src/merzbild.jl") and using ..Merzbild to the file.

Documentation

The documentation assumes a certain level of pre-existing knowledge of the DSMC approach. Basic building blocks and operations (particle indexing, sampling, collisions, I/O) are covered in the Getting Started section.

More specific examples (ionizing collisions, specific merging algorithms) will be published later in a Tutorials section.

Finally, a full API reference is present, split into the Merzbild.jl public API reference and Merzbild.jl internal API reference.

Citing

You can for now cite the repository as

@misc{oblapenko2024merzbild,
  title={{M}erzbild.jl: A {J}ulia {DSMC} code},
  author={Oblapenko, Georgii},
  year={2024},
  month={12},
  howpublished={\url{https://github.com/merzbild/Merzbild.jl}},
  doi={10.5281/zenodo.14503197}
}

Depending on the functionality used, other citations may be warranted, please look at the Overview of capabilities page to see which algorithms and models have been implemented in Merzbild.