Three-dimensional numerical model of ion optics system

Hayakawa, Yukio

doi:10.2514/3.23450

Cited by 22 publications

(6 citation statements)

References 8 publications

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“…The majority of ion-optics models are designed for single-aperture-pair ion optics considering the six-fold hexagonal symmetry of the aperture array. [7][8][9][10][11][12] Wang et al developed a three-dimensional ion-optics model designed in such a way that not only a single aperture but also multiple apertures can be included in the simulation domain; however, their simulations were performed only with two quarter-size apertures. 13 The model was extended to a 7-aperture grid by several authors, 14,15 who used the symmetry of the plasma shape and the aperture arrangement to reduce the size of the simulation domain.…”

Section: Introductionmentioning

confidence: 99%

Numerical simulation of full-aperture-pair ion optics in a miniature ion thruster

et al. 2018

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The 211-aperture-pair two-grid ion optics of a miniature ion thruster is numerically simulated. Since the plasma in the miniature ion thruster is too inhomogeneous to introduce mirror or translational boundary conditions between apertures, all the apertures of the grid system are considered. The simulation is self-consistent, the ion current profile in the discharge chamber plasma is given by the particle-in-cell with Monte Carlo collision algorithm calculations, and all the ion beams extracted from the full-aperture-pair array were tracked including charge-exchange ions. A scheme for the construction of the full-aperture-pair simulation domain is proposed based on the array of a six-fold hexagonal single-aperture-pair simulation domain, which can be extended to other numbers of aperture pairs. Numerical results on accel impingement current and ion-beam profile are compared to experimental data and shown to be in reasonable agreement. Furthermore, the full-aperture-pair ion-optics model is compared with the single-aperture-pair ion-optics models used in the majority of previous ion-optics simulations, which showed that the full-aperture-pair ion-optics model yielded the most accurate predictions. These results suggest that the ion thruster grid system using an inhomogeneous plasma source can be designed more accurately and effectively using full-aperture-pair ion-optics simulations.

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Section: Introductionmentioning

confidence: 99%

Numerical simulation of full-aperture-pair ion optics in a miniature ion thruster

et al. 2018

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“…The nature of plasma flow in ion optics renders particle-in-cell (PIC) [1] based models, which simulate a collisionless plasma by solving plasma particle trajectories, space charge, and the electric field self-consistently as the most appropriate approach for ion optics modeling. Numerous PIC-based ion optics simulation codes have been developed (see, for example, [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] and references therein). Whereas earlier studies have focused on the physics of a single beamlet, recent studies have also begun to use ion optics models to predict the behavior of entire ion optics.…”

mentioning

confidence: 99%

Whole Ion Optics Gridlet Simulations Using a Hybrid-Grid Immersed-Finite-Element Particle-in-Cell Code

Kafafy

Wang

2007

Journal of Propulsion and Power

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A new model is developed for three-dimensional global simulations of plasma flow in an entire subscale ion optics. This model explicitly includes apertures located near the edge of the grid surface and fully accounts for the effects of multiple ion beamlets and geometric asymmetry. This model is based on a new algorithm, the streamline hybrid-grid immersed-finite-element particle-in-cell. This algorithm is capable of achieving the same accuracy as an unstructured body-fit mesh-based particle-in-cell with a faster computational speed. Simulation results are presented to understand the plasma sheath upstream of the screen grid, direct impingement of beam ions, the crossover limit, the perveance limit, and the electron backstreaming onset. Nomenclature e = electron charge F = force vector I = current k = Boltzmann constant m = mass q = charge T = temperature t = time v = velocity vector x = position vector = IFE mesh stretching parameter 0 = electric permittivity of vacuum D = Debye length = charge density = electrostatic potential Subscripts a = accelerator grid b= beamlet cc = center-to-center e = electron g = gap between ion optics grids i = ion, or impingement s = screen grid w = grid wall 0 = upstream plasma condition 1 = downstream plasma condition

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“…With the charged droplet entering the computation domain, the effect of space charge on electric field was resolved through a PIC method (Hayakawa, 1992). The motion of droplets was then calculated using Eqs.…”

Section: Numerical Proceduresmentioning

confidence: 99%