Numerical investigation of plasma behavior in a micro DC ion thruster using the particle-in-cell/Monte Carlo collision (PIC/MCC) method

Liu, Wei; Cai, Guobiao; Zhang, Jinrui; Xia, Guangqing; Wang, Weizong

doi:10.1088/1361-6463/ac1a0c

Cited by 10 publications

(12 citation statements)

References 55 publications

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“…The PIC-MCC code we use was validated using the CCP benchmark proposed by Turner et al [53]. Details can be found in our most recent work in reference [54]. The RF frequency used in simulations is set to 13.56 MHz which is consistent with that in the experiments.…”

Section: Electron-neutralmentioning

confidence: 99%

Radio-frequency biasing of ion acceleration grids with different propellants

Tang

Cai

et al. 2022

Plasma Sources Sci. Technol.

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In order to ensure the space charge compensation of the plume, conventional ion thrusters need an additional neutralizer to release electrons. When a radio-frequency (RF) voltage is applied across the grid system instead of a direct-current (DC) voltage, the simultaneous extraction of ions and electrons is achieved, thereby a neutralizer is not required. In this paper, based on the non-uniform distribution of neutral gas density calculated using the angular coefficient method, the particle-in-cell Monte Carlo collision (PIC-MCC) method is used to thoroughly investigate the spatial and temporal dynamics of particles and the grid system performance for different propellants (argon, krypton and xenon) in such an RF grid system. RPA and E×B probe are employed to measure the IFDFs of RF ion thruster with RF biasing, which are used to compare with the simulations. The simulated linear relationship between the self-bias voltage and the RF voltage amplitude and the multi-peak behavior of ion flux distribution function (IFDF) under low RF frequency conditions are comparable with the experimental data. The simulated IFDFs compare well with the experiments with the deviation of energy peak position less than 7% and 10% from those by RPA and E×B probe respectively, indicating the effectiveness of the used model. Simulations show the RF grid system is able to realize the extraction of electrons for all three propellants, so as to achieve the plume neutralization without an external neutralizer through the spatial and temporal oscillations of the beams. Electrons pass through the grid twice (extracted from the upstream, and backflow from the downstream), bringing two peaks of electron current to the accelerator grid in one period. The thrust-RF voltage curves for all three propellants show obvious slope transition, when the perveance limit is reached. The low-energy ions in the plume are mainly generated by the electron impact ionization processes for Xe while by CEX collisions for Ar. A larger ion current density of Xe on the downstream surface of the accelerator grid, which may lead to possibly more serious erosions of grids, is found compared with those of Kr and Ar. This is mainly contributed by the larger density of electron impact ionization generated ions of Xe in the downstream because Xe propellant has a larger electron density and ionization cross-section.

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Section: Electron-neutralmentioning

confidence: 99%

Radio-frequency biasing of ion acceleration grids with different propellants

Tang

Cai

et al. 2022

Plasma Sources Sci. Technol.

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“…For charge exchange collisions, the velocity of the incident ion and the neutral particle are exchanged. The species interaction types as well as the collision cross-sections used to describe the interactions are summarized in table 2 and more details can be found in our recent study on PIC/MCC simulation [33].…”

Section: Motion and Collisions Of Plasma Particlesmentioning

confidence: 99%

Kinetic simulations of low-pressure inductively coupled plasma: an implicit electromagnetic PIC/MCC model with the ADI-FDTD method

Fu,

Dong,

et al. 2024

J. Phys. D: Appl. Phys.

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Low-pressure inductively coupled plasma (ICP) is promising for space electric propulsion. For the first time, an implicit electromagnetic particle-in-cell Monte Carlo collision model based on the alternating-direction-implicit finite-difference time-domain (ADI-FDTD) method is developed to investigate low-pressure xenon plasma characteristics of a miniature ICP source. The induced simulated electric field is well consistent with that calculated by the finite element method, indicating that this method can provide an accurate estimation of the electromagnetic field. The simulation time step used in the ADI-FDTD method is no longer restricted by the Courant–Friedrichs–Lewy constraints. Compared with the FDTD method, the ADI-FDTD method increases the size of the time step and significantly improves computational efficiency. The method is validated by comparing the simulated and measured electron density and plasma potential profile and reasonable agreement is reached. Therefore, the model is used to investigate the temporal and spatial distribution of plasma properties and the influence of the current amplitude of radio frequency (RF) coil, applied frequency of RF coil and neutral gas pressure on the plasma dynamics in the ionization chamber of a miniature gridded RF ion thruster. To explain the influence of the operating parameters, a concept called ‘the energy relaxation characteristics of electrons in response to the change of electric field’ is proposed and verified. The simulations also find that the oscillation frequency of plasma properties is twice the applied frequency of RF coil. The oscillation characteristics reveal the dynamic energy balance in the ICP. The experiment on the gridded RF ion thruster BHRIT-4 confirms the oscillation by measuring the plasma sheath potential.

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“…The particle weighting method was cloud-in-cell [43]. The code was developed for this work based on the code in [13,32]. The limitations of the downstream floating boundary and the domain length on the order of 10 mm in the RF grid system simulations have been discussed in [30].…”

Section: Simulation Domainmentioning

confidence: 99%

“…Examples include the Beihangkongshi-1 satellite with NPT30-I2 that was injected into a circular, Sun-synchronous orbit [1], the European Space Agency's (ESA) BepiColombo mission to Mercury with the T6 Kaufmann-type thruster [2][3][4], the satellite SJ-9 A with the LIPS-200 ion thruster which carried out an ion electric propulsion system flight test plan [5,6], the gravity field and steady-state ocean circulation explorer (GOCE) mission using the T5 Kaufmann type thruster for drag compensation [7], the Dawn mission and the Deep Space 1 mission with the NASA Solar Technology Application Readiness (NSTAR) ion thruster of the National Aeronautics and Space Administration [8][9][10], the Japanese Aerospace Exploration Agency's Hayabusa sample-return missions with the µ10 thruster to the near-Earth asteroids [11], [12]. Meanwhile, the working mechanism of the ion thruster has also been extensively studied, including the discharge chamber [13][14][15][16] that generates plasma and the optic system [17][18][19][20][21][22] that provides thrust.…”

Section: Introductionmentioning

confidence: 99%

Three-dimensional analysis of RF-biased ion optics with misalignments of apertures

Wang

Liu

et al. 2023

Plasma Sources Sci. Technol.

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The accelerator grid holes shift is a critical reason for erosion failure of optic systems in ion thrusters, which may also cause an unexpected roll torque about the ion beam axis. A three-dimensional model of ion optics is developed based on particle-in-cell Monte Carlo collision (PIC-MCC) method to investigate the plasma dynamics and performance of the radio frequency (RF) grid systems with misalignments of apertures, which are compared with those in the direct current (DC) grid system. For benchmark case, the three-dimensional model gives a better agreement with the experiments in the ion energy distribution function (IEDF) compared with the two-dimensional model from a previous publication, with 36.4% and 47.9% relative error reduction of the peak position and full width at half maximum (FWHM) respectively, indicating the effectiveness of the developed three-dimensional model. Simulations show that in the RF grid system the ion beamlet is deflected in the direction opposite to the shift of the accelerator grid hole, while electrons move first in the holes shift direction, and then deflect in the opposite direction. The average ion beamlet deflection angle calculated is consistent with the predictions by the linear optical theory in both the RF and DC grid system. The amplitude of beamlet deflection angle fluctuation with time decreases with the increase of RF frequency. When the grid holes shift, the ion beamlet will deflect with the divergence angle almost unchanged in the DC grid system, while the beamlet divergence angle increases in the RF grid system. When RF frequency is low, the big vortex-like structure in electron velocity phase diagram breaks into small vortices, showing a reduced oscillation intensity. The holes shift also causes high-frequency oscillation in the shift direction. In terms of performance, RF grid system is more sensitive to grid holes shift than DC grid system.

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Numerical investigation of plasma behavior in a micro DC ion thruster using the particle-in-cell/Monte Carlo collision (PIC/MCC) method

Cited by 10 publications

References 55 publications

Radio-frequency biasing of ion acceleration grids with different propellants

Radio-frequency biasing of ion acceleration grids with different propellants

Kinetic simulations of low-pressure inductively coupled plasma: an implicit electromagnetic PIC/MCC model with the ADI-FDTD method

Three-dimensional analysis of RF-biased ion optics with misalignments of apertures

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