Electron kinetics in fast-pulsed discharges*

This work presents a comparative study of the electron kinetics in fast-pulsed discharges produced in dry air (80{\%} N$_{\mathrm{2}}$ - 20{\%} O$_{\mathrm{2}})$, considering a quasi-stationary and a time-dependent solution of the electron Boltzmann equation (EBE), written under the classical two-term approximation. The simulations were performed using the open-source LisbOn KInetics Boltzmann solver (LoKI-B) [1,2], which handles simulations in any atomic / molecular gas mixture, considering first and second kind collisions with any target state (electronic, vibrational and rotational), characterized by any user-prescribed population. The original capabilities of LoKI-B have been extended in order to obtain the time-dependent solution of the EBE for a pulsed electric field. Noticeable deviations, between the quasi-stationary and the time-dependent calculations of the electron energy distribution function and related macroscopic coefficients, are observed below the microsecond scale, for a pulse peaking at 45 Td with rise and fall times of \textasciitilde 1$\mu $s and \textasciitilde 10$\mu $s, respectively. \newline [1] A. Tejero-del-Caz \textit{et al}, Plasmas Sources Sci. Technol. \textbf{28} (2019) 043001 \newline [2] \underline {https://github.com/IST-Lisbon/LoKI}