LoKI-B C++: An open-source Boltzmann solver for reproducible electron Boltzmann calculations*

Boltzmann solvers are essential for low-temperature plasma simulation, as they calculate the (non-Maxwellian) electron energy distribution function (EEDF). They use electron scattering cross sections as input and produce swarm parameters as output, which can be used for further plasma modeling. The Lisbon KInetics Boltzmann solver (LoKI-B) [1] (https://github.com/IST-Lisbon/LoKI), was developed to handle complex molecular gas mixtures and offer a transparent alternative to existing solutions. Originally written in Matlab, LoKI-B is now extended to a C++ version, incorporating additional features.

LoKI-B C++ (https://github.com/LoKI-Suite/LoKI-B) focuses on sound open-source practices like test-driven development, code coverage metrics, and continuous integration and deployment. This work presents benchmarks, numerical improvements; such as exploratory work on a nonuniform discretization of the electron energy, and data management enhancements. Usability is improved by providing a free, fully-featured instance of LoKI-B C++ in the browser via compilation to WebAssembly. Combined with the recent LXCat3 [2] developments (https://github.com/LXCat-project/LXCat), it enables transparent, reproducible electron Boltzmann computations. A live demo will be available at the poster.

[1] Tejero-del-caz et al: 2019, Plasma Sources Sci. Technol. 28 043001, https://doi.org/10.1088/1361-6595/ab0537

[2] Carbone E.A.D. et al.: 2021, Atoms 9, 16, https://doi.org/10.3390/atoms9010016