Plasmonic effects in the neutralization of slow ions at a metallic surface

Secondary electron emission is an important process that plays a significant role in several plasma-related applications. As measuring the secondary electron yield experimentally is very challenging, quantitative modelling of this process to obtain reliable yield data is critical as input for higher-scale simulations. Here, we build upon our previous work combining density functional theory calculations with a model originally developed by Hagstrum to extend its application to metallic surfaces. As plasmonic effects play a much more important role in the secondary electron emission mechanism for metals, we introduce an approach based on Poisson point processes to include both surface and bulk plasmon excitations to the process. The resulting model is able to reproduce the yield spectra of several available experimental results quite well but requires the introduction of global fitting parameters, which describe the strength of the plasmon interactions. Finally, we use an in-house developed workflow to calculate the electron yield for a list of elemental surfaces spanning the periodic table to produce an extensive data set for the community and compare our results with more simplified approaches from the literature.

Automated summary

Secondary electron emission is an important process in plasma-related applications and its quantification is challenging. This study combines density functional theory calculations with a modified Hagstrum model to simulate the mechanism of secondary electron emission on metallic surfaces. By introducing plasmonic effects, the model successfully reproduces experimental results. Additionally, the researchers calculate electron yields for various elemental surfaces and compare their results with simplified approaches from literature.