Simulation study of influence of exit magnetic separatrix angle on plume divergence control

Liu, Hui; Niu, Xiang; Li, Xin; Yu, Daren

doi:10.1140/epjd/e2020-100595-0

Cited by 6 publications

(3 citation statements)

References 23 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

“…As the thruster is an axisymmetric structure, in this work we use a 2D axisymmetric simulation. This model has been used to study Hall thrusters [24,25], multi-cusped field thrusters [26,27], near-wall conductivity [28], and power deposition on the wall and erosion [29]. The simulation area includes the channel and near field plume area.…”

Section: D Calculation Modelmentioning

confidence: 99%

Influence of neutral gas supply position on wall erosion of Hall thruster studied by particle-in-cell simulation

Cao¹,

Xia²,

Liu³

et al. 2023

Plasma Sci. Technol.

Self Cite

View full text Add to dashboard Cite

In this work, we have carried out the simulation study on the discharge process of Hall thruster under the conditions of different neutral gas radial supply positions based on particle-in-cell method (PIC) and Monte Carlo collision method (MCC). This paper compares the two-dimensional (2D) distributions of neutral gas, plasma and the distributions of wall erosion related parameters under different neutral gas supply positions. The comparison results show that the change of the neutral gas supply position will affect the radial distribution uniformity of the neutral gas and plasma in the channel. From the comparison of the density peaks, it can be found that the neutral gas density and the plasma density peak under the upper gas supply condition are relatively low, and the plasma density peak is 22.49% lower than the density peak under the middle gas supply condition. Meanwhile, as the radial position of the gas supply moves from the lower gas supply to the upper gas supply, the position of the ionization zone also gradually moves toward the anode. The comparison results of erosion related parameter distribution show that the change of gas supply location has obvious influence on erosion rate and erosion range. In terms of erosion rate, the wall erosion rate is relatively low under the upper gas supply condition, and the peak erosion rates of inner and outer walls are 33.3% and 29.9% lower than those under the other two conditions. In terms of erosion range, the gas supply position moves from the lower gas supply position to the upper gas supply position, the erosion range gradually increases from 5 to 7.5 mm.

show abstract

“…This demonstrates that the ion density peak location does not correlate well with the cathode position. It is generally accepted that the outgoing angle of the ion flux is highly correlated with the last separatrix in a cusped field thruster [27]. Even though the migration path of the source electrons impacts the ion current density at small angles, the inherent magnetic topology of the thruster is dominant over the peak location.…”

Section: On Propellant Ionizationmentioning

confidence: 99%

Cathode position effects on microwave discharge cusped field thruster

Zeng¹,

Liu²,

Chen³

et al. 2023

Plasma Sci. Technol.

Self Cite

View full text Add to dashboard Cite

The microwave discharge cusped field thruster is a novel concept of electric micro propulsion device, which operates μN level thrust in low mass flow rate conditions, making use of a coaxial transmission line resonator (CTLR). With the advantages of low thrust noise and high thrust resolution over a wide range of thrust, the thruster becomes a candidate thruster for the Gravitational Wave detection mission. The cathode effects commonly exist in many kinds of electric propulsions, and they are typically significant in micro propulsions. In order to find out the cathode position effects on microwave discharge cusped field thruster, a thermionic cathode is mounted on a cross-slider for the coupling. With cathode position varies, the plume is analyzed by a Faraday probe and an RPA to analyze the performance and discharge characteristics. The results show that the magnetic mirror effect leads to significant degradation of anode current and an increase in low-energy ion ratio as the cathode moves away from the thruster exit. The electron conduction route also significantly impacts anode current efficiency, related to the cathode-exit distance and the thruster magnetic topology.

show abstract

Simulation study of influence of exit magnetic separatrix angle on plume divergence control

Cited by 6 publications

References 23 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

Influence of neutral gas supply position on wall erosion of Hall thruster studied by particle-in-cell simulation

Cathode position effects on microwave discharge cusped field thruster

Contact Info

Product

Resources

About