O Collision Cross Sections for Plasma Modelling*

Although water is omnipresent in many plasma applications, often it is not taken into account in plasma

modelling, partially due to the lack of reliable and accessible cross sections. Electron-neutral collision cross

sections are optimised by the electron swarm method assuming isotropic inelastic collisions, yielding a complete

cross section set that is consistent with experiments [1] for use in space-homogeneous codes like common

two-term Boltzmann solvers [2]. The set is made available in the IST-Lisbon database on LXCat [3], giving the

community the immediate tools to develop more sophisticated plasma kinetics and chemistry models.

From there, the study is extended to anisotropic rotational collisions [4] and the set is benchmarked for use in

other codes like those considering electron density gradients or Monte Carlo simulations. In conclusion, the set

can be recommended based on a thorough quantitative analysis to improve plasma models and the understanding

of experiments.

References

[1] M. Budde, T. C. Dias, L. Vialetto, N. Pinhão, V. Guerra and T. Silva 2022 J. Phys. D: Appl. Phys. submitted

for publication

[2] A. Tejero-del-Caz, V. Guerra, D. Gonçalves, M. Lino da Silva, L. Marques, N. Pinhão, C. D. Pintassilgo

and L. L. Alves 2019 Plasma Sources Sci. Technol. 28 043001

[3] L. L. Alves 2014 J. Phys.: Conf. Ser. 565 012007

[4] L. Vialetto, A. Ben Moussa, J. van Dijk, S. Longo, P. Diomede, V. Guerra and L. L. Alves 2021 Plasma

Sources Sci. Technol. 30 075001