Two-dimensional kinetic modeling of a hollow cathode

Hollow cathodes are efficient sources of plasma, which have found extensive applications in various fields such as electric propulsion, surface processing, and plasma-material interac8on studies. In state-of-the-art fluid models [1,2], electrons are assumed to thermalize quickly, and ionization occurs in the bulk. In this work, we find that under certain operating conditions, electrons can display a non-Maxwellian energy distribution function (EEDF), which affects the ionization processes and temperature. We derive subsequent analytical models in the channel and in the plume to describe the plasma dynamics. We use the explicit Particle-In-Cell code EDIPIC-2D (hRps://github.com/PrincetonUniversity/EDIPIC-2D) to conduct our inves8ga8on.

1 G. Sary, L. Garrigues, and J.-P. Boeuf, “Hollow cathode modeling: I. A coupled plasma thermal two-dimensional model,” Plasma Sources Sci. Technol. 26(5), 055007 (2017).

2 D.M. Goebel, G. Becatti, I.G. Mikellides, and A. Lopez Ortega, “Plasma hollow cathodes,” Journal of Applied Physics 130(5), 050902 (2021).