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DEVELOPMENT A MATHEMATICAL MODEL OF PROCESSES INSIDE RF HOLLOW CATHODE TAKING VISCOSITY INTO ACCOUNT IN ELECTRON DYNAMICS

Technology Audit and Production Reserves | 2026

Paper Details

Authors: Roshanpour S.

DOI: 10.15587/2706-5448.2026.356937

Journal: Technology Audit and Production Reserves

Year: 2026

Publisher: Technology Center

Document Type: Article

Open Access: All Open Access; Gold Open Access

Cited by: 0

Abstract

The object of research is high-frequency hollow cathode as electron sources in plasma-ion thrusters and Hall effect thrusters with relatively low-power. Publications devoted to high-frequency (helicon) thrusters consider Trivelpiece-Gould waves, helicon waves, as well as ion-cyclotron and electron-cyclotron resonance, as mechanisms for absorbing electromagnetic energy. In this case, electron scattering by atoms and ions within the thruster channel is considered a factor in plasma thermalization. The discharge conditions and the dimensions of the low-power cathode cavity virtually eliminate the occurrence of these effects, while significantly enhancing the relaxation of electron momentum due to non-mirror reflection from the potential barrier in the boundary bipolar layer. The parameters describing the results of this reflection within the cavity volume are the axial-azimuth and radial-azimuth components of the electron viscosity tensor, corresponding to the electron momentum flux in the direction of zero mass flow. It is shown that viscous electron momentum transport facilitates magnetic field penetration deeper into the plasma than is predicted by classical skin-layer theory, which considers the relaxation of electrons motion only because of collisions in the volume. Conditions under which rotation-cyclotron resonance is possible are identified. The input of viscosity into electrons thermalization process is shown. The results obtained in the work can be used in predicting operating parameters and narrowing the range of parameter variations when developing laboratory models. © The Author(s) 2026.

Keywords

bipolar layer; high-frequency cathode; potential barrier; skin-layer; viscosity tensor