Numerical simulation study on the influence of channel geometry on discharge characteristics of low-power magnetically shielded Hall thrusters

Ma, Dezhu; Zeng, Demai; Wang, Lei; Ding, Yongjie; Wei, Liqiu; Li, Hong; Yu, Daren

doi:10.1016/j.vacuum.2020.109547

Cited by 14 publications

(5 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In order to relax these severe numerical constraints on the length and time scales, and speed-up the simulation, an augmentation factor, f D > 1 is introduced, which defines an augmented permittivity ε = ε 0 f 2 D , with ε 0 the physical vacuum permittivity, yielding ω −1 pe , λ D ∝ f D . Values of f D ∼ 12−40 have been used in other previous axial-radial PIC studies [31,[40][41][42]. An augmented Debye length smooths the potential profiles in the Debye sheaths and should not generate major distortions in the discharge as long as λ D remains the smallest length scale of the problem.…”

Section: Considerations On Timestep and Cell Sizementioning

confidence: 99%

Non-Maxwellian electron effects on the macroscopic response of a Hall thruster discharge from an axial–radial kinetic model

Marín-Cebrián,

Bello-Benítez,

Domínguez-Vázquez

et al. 2024

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

A 2D axial-radial particle-in-cell (PIC) model of a Hall thruster discharge has been developed to analyze (mainly) the fluid equations satisfied by the azimuthally-averaged slow dynamics of electrons. Their weak collisionality together with a strong interaction with the thruster walls lead to a non-Maxwellian velocity distribution function (VDF). Consequently, the resulting macroscopic response differs from a conventional collisional fluid. First, the gyrotropic (diagonal) part of the pressure tensor is anisotropic. Second, its gyroviscous part, although small, is relevant in the azimuthal momentum balance, where the dominant contributions are orders of magnitude lower than in the axial momentum balance. Third, the heat flux vector does not satisfy simple laws, although convective and conductive behaviors can be identified for the parallel and perpendicular components, respectively. And fourth, the electron wall interaction parameters can differ largely from the classical sheath theory, based on near Maxwellian VDF. Furthermore, these effects behave differently in the near-anode and near-exit regions of the channel. Still, the profiles of basic plasma magnitudes agree well with those of 1D axial fluid models. To facilitate the interpretation of the plasma response, a quasiplanar geometry, a purely-radial magnetic field, and a simple empirical model of cross-field transport were used; but realistic configurations and a more elaborated anomalous diffusion formulation can be incorporated. Computational time was controlled by using an augmented vacuum permittivity and a stationary depletion law for neutrals.

show abstract

Section: Considerations On Timestep and Cell Sizementioning

confidence: 99%

Non-Maxwellian electron effects on the macroscopic response of a Hall thruster discharge from an axial–radial kinetic model

Marín-Cebrián,

Bello-Benítez,

Domínguez-Vázquez

et al. 2024

Plasma Sources Sci. Technol.

View full text Add to dashboard Cite

show abstract

“…Overall, for minimum divergence angle, the middle coil should be as close as possible to the rightmost coil, and hence, we take the spacing ratio as 0.73 considering the practicality for designing the setup. The tuning of divergence angle through the radial and axial components of the magnetic field has important application in magnetically shielded Hall thrusters also [33], where the axial variation of the radial component plays a vital role.…”

Section: Three-coil Setup For Magnetic Nozzlementioning

confidence: 99%

A Three-Coil Setup for Controlled Divergence in Magnetic Nozzle

Malik

Kumar

Singh

2021

IEEE Trans. Plasma Sci.

View full text Add to dashboard Cite

Magnetic nozzles with their contactless feature have opened new grounds for long-distance space travels. For quicker mission completions along with improving system reliability, it becomes necessary to design robust systems that exhibit the ability to confine thrust. A semianalytical numerical method is proposed for rapid and assumption-less calculations of the magnetic field because of a thick coil with rectangular cross section. The method is extended for the proposal of a three-coil setup, where divergence angle of the magnetic field lines is readily controlled in-flight to provide the flexibility to modify the output magnetic thrust and the nozzle's efficiency.

show abstract

“…The ratio of the mean free path of the xenon atom to the channel characteristic length in the Hall thruster is greater than 10, which satisfies the condition that the Knudsen coefficient exceeds 10. Therefore, the free molecular flow model can be used to simulate anode distribution [35]. The atom density distributions of the channel centerline in the steady-state for the different cases are shown in figure 10.…”

Section: Discharge Characteristicsmentioning

confidence: 99%

Matching characteristics of magnetic field configuration and chamfered channel wall in a magnetically shielded Hall thruster

Wang

Zhong

et al. 2021

Plasma Sci. Technol.

Self Cite

View full text Add to dashboard Cite

To date, the selection of the magnetic field line used to match the chamfered inner and outer channel walls in a magnetically shielded Hall thruster has not been quantitatively studied. Hence, an experimental study was conducted on a 1.35 kW magnetically shielded Hall thruster with a xenon propellant. Different magnetic field lines were chosen, and corresponding tangentially matched channel walls were manufactured and utilized. The results demonstrate that high performance and a qualified anti-sputtering effect cannot be achieved simultaneously. When the magnetic field lines that match the chamfered wall have a strength at the channel centerline of less than 12% of the maximum field strength, the channel wall can be adequately protected from ion sputtering. When the magnetic field lines have a strength ratio of 12%-20%, the thruster performance is high. These findings provide the first significant quantitative design reference for the match between the magnetic field line and chamfered channel wall in magnetically shielded Hall thrusters.

show abstract

Numerical simulation study on the influence of channel geometry on discharge characteristics of low-power magnetically shielded Hall thrusters

Cited by 14 publications

References 18 publications

Non-Maxwellian electron effects on the macroscopic response of a Hall thruster discharge from an axial–radial kinetic model

Non-Maxwellian electron effects on the macroscopic response of a Hall thruster discharge from an axial–radial kinetic model

A Three-Coil Setup for Controlled Divergence in Magnetic Nozzle

Matching characteristics of magnetic field configuration and chamfered channel wall in a magnetically shielded Hall thruster

Contact Info

Product

Resources

About