Erlangen 2026 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

P: Fachverband Plasmaphysik

P 16: Poster Session Plasma Physics

P 16.32: Poster

Thursday, March 19, 2026, 13:45–15:45, Redoutensaal

Microphysical boundary condition for the electron Boltzmann equation of a plasma — Felix Willert¹, •Clemens Hoyer¹, Gordon K. Grubert², and Franz X. Bronold¹ — ¹Institut für Physik, Universität Greifswald, 17489 Greifswald, Germany — ²Universitätsrechenzentrum, Universität Greifswald, 17489 Greifswald, Germany

We set up an energy- and angle-dependent boundary condition for the electron Boltzmann equation containing the electron microphysics inside the wall [1]. At low energies the boundary condition is based entirely on a computed electron surface scattering kernel [2], while at higher energies measured emission yields are, in addition, fed into the microscopic model to obtain plausible data also in this energy range. We incorporate the kernel within the expansion approach of solving the electron Boltzmann equation, expanding the electron distribution function in Legendre polynomials and linking the expansion coefficients to the moments of the electron flux at the plasma-wall interface, but it can be also implemented in a PIC-MCC simulation of the plasma’s electron kinetics. Numerical results for argon, helium, and oxygen plasmas in contact with Si and SiO₂ surfaces are presented, showing in particular the significance of the inelasticity of the microphysics-based boundary condition compared to an energy- and angle independent phenomenological one. [1] F. Willert et al., arXiv:2511.20346 (2025). [2] F.X. Bronold and F. Willert, Phys. Rev. E 110, 035207 (2024). F.X.B. and F.W. acknowledge support by Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)–495729137.

Keywords: Boltzmann equation; Legendre expansion; secondary electron emission; plasma-wall interaction