MCPlas, a MATLAB toolbox for reproducible plasma modelling with COMSOL

TL;DR

MCPlas addresses reproducibility and interoperability in fluid-Poisson modelling of non-thermal plasmas by encoding all model data in JSON schemas aligned with LXCat and Plasma-MDS, and by automating COMSOL model generation via LiveLink for MATLAB. It offers multiple geometries and electron-transport descriptions, notably the DDAn scheme, and provides stabilisation and boundary-treatment enhancements to improve robustness. The toolbox is validated against the COMSOL Plasma Module for DC and RF argon discharges, and demonstrates the ability to reuse complex RKMs (e.g., 23-species) across different simulation tools (PLASIMO, FEDM), illustrating FAIR data principles in practice. Overall, MCPlas provides a transparent, reusable, and cross-platform framework that lowers barriers to reproducible plasma modelling while enabling detailed chemistry and boundary physics to be explored with consistent input data.

Abstract

The MCPlas toolbox represents a collection of MATLAB functions for the automated generation of an equation-based fluid-Poisson model for non-thermal plasmas in the multiphysics simulation software COMSOL. Following the development of the new generation of the LXCat platform, all input data are prepared in a structured and interoperable JSON format and can be supplied and validated using existing JSON schemas. The toolbox includes fully transparent, editable MATLAB source code and offers an advanced description of electron transport in addition to commonly used approaches in the plasma modelling community. It supports one-dimensional and two-dimensional modelling geometries employing Cartesian, polar and cylindrical coordinate systems. MCPlas is tested on two reference cases: DC- and RF-driven low-pressure glow discharges in argon. Comparison of MCPlas results with results obtained by employing COMSOL's Plasma Module verifies the reliability of the plasma model implemented by MCPlas and demonstrates the significance of electron transport treatment and boundary conditions applied in the toolbox. Using the same examples, the easy handling of complex reaction kinetic models in MCPlas and the reusability of its JSON input data across different modelling platforms are illustrated. This demonstrates that MCPlas provides a transparent and reproducible workflow for the simulation of non-thermal plasmas using COMSOL.

Figures (17)

• Figure 1: Modelling geometries supported by MCPlas toolbox ($d$ - discharge gap, $\Delta_\mathrm{d}$ - dielectric thickness, $L_\mathrm{e}$ - electrode length and $R_\mathrm{e}$ - electrode radius).
• Figure 2: Illustration of the MCPlas workflows including the provision of input data (1), the processing (2), (3) and the implemented plasma model in COMSOL (4).
• Figure 3: Schematic representation of the top-level structure of an LXCat JSON document for LTP input data.
• Figure 4: Example of a JSON object representing a reference, as defined by the CSL-JSON schema.
• Figure 5: Example of a key-value pair from the states property. The JSON object defines the argon $\mathrm{1s5}$ metastable state using the $\mathrm{J_1L_2}$ coupling scheme. The info property stores an array of different data related to the species, some possible options are Mass, Energy, Mobility, and DiffusionCoefficient. The Ar[1s5] key can be used to reference this state in other parts of the document.