A one-dimensional with three-dimensional velocity space hybrid-PIC model of the discharge plasma in a Hall thruster

Abstract

According to present knowledge, countless numerical simulations of the discharge plasma in Hall thrusters were conducted. However, on the one hand, adequate two-dimensional (2D) models require a lot of time to carry out numerical research of the breathing mode oscillations or the discharge structure. On the other hand, existing one-dimensional (1D) models are usually too simplistic and do not take into consideration such important phenomena as neutral-wall collisions, magnetic field induced by Hall current and double, secondary, and stepwise ionizations together. In this paper a one-dimensional with three-dimensional velocity space (1D3V) hybrid-PIC model is presented. The model is able to incorporate all the phenomena mentioned above. A new method of neutral-wall collisions simulation in described space was developed and validated. Simulation results obtained for KM-88 and KM-60 thrusters are in a good agreement with experimental data. The Bohm collision coefficient was the same for both thrusters. Neutral-wall collisions, doubly charged ions, and induced magnetic field were proved to stabilize the breathing mode oscillations in a Hall thruster under some circumstances.

Numerical study of viscosity and heat flux role in heavy species dynamics in Hall thruster discharge

“…In the case where > z z , 6 the conductivity coefficient becomes constant = a f . 6 The coefficients z j and f j were calculated in the 1D3V hybrid model [9,54] using the adjustment of the anomalous conductivity profile to experimentally measure the operating parameters described in detail in [55]. Figure 4 shows the anomalous collision frequency profile in comparison with classical collision frequencies and the electron cyclotron frequency.…”

“…The first criterion is the number of dimensions of modeling. The models could be one-dimensional (1D) (axial (Z) [1][2][3][4][5][6][7][8][9], radial (R) [10,11] and azimuthal (q) [12][13][14][15]), two-dimensional (2D) (Z-R plane [16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33], Z-q plane [34][35][36][37][38]), or threedimensional (3D) [39,40]. On one hand, 1D models do not correctly take into account the essential curvature of the magnetic field lines and plasma-wall interaction.…”

Machine learning-based method to adjust electron anomalous conductivity profile to experimentally measured operating parameters of Hall thruster

“…where ano n is the frequency of the effective anomalous collisions, a is the proportion coefficient and c w is the electron cyclotron frequency. Many papers utilize the Bohm collision model due to its simplicity [12][13][14][15][16][17][18][19][20]. However, this approximation yields an unfeasible distortion of the plasma layer location and causes the dependence of the plasma layer width on cathode boundary location [21].…”

Fluid and hybrid simulations of the ionization instabilities in Hall thruster

“…Therefore further insights on key physical processes are required to expand the predicting powers of such models, especially to new parameters range and new operational regimes. While many numerical models for breathing modes based on fully fluid formulations, timedependent, the hybrid modeling was also undertaken using the kinetic description for ions and neutrals 15,18,19,[22][23][24] . The extent to which the ion and neutrals kinetic effects influence the breathing mode excitation and characteristics remain a mute point of many studies.…”