DocumentCode :
72262
Title :
Ion Beam Instability in Hall Thrusters
Author :
Kapulkin, A. ; Behar, E.
Author_Institution :
Asher Space Res. Inst., Technion - Israel Inst. of Technol., Haifa, Israel
Volume :
43
Issue :
1
fYear :
2015
fDate :
Jan. 2015
Firstpage :
64
Lastpage :
71
Abstract :
Stability of an ion flux, bounded with an anode and cathode, in Hall thrusters is investigated by theoretical and numerical modeling. Two-fluid magnetohydrodynamic approximation with cold magnetized electrons and cold nonmagnetized ions is used. The inertia of the electrons is taken into consideration. The perturbations are assumed to be quasi-neutral, potential, and dependent on a single spatial coordinate only. For simplicity, the magnetic field is assumed to be uniform. It is shown that the presence of the boundaries, where the potential of the ion beam is fixed, can cause instability of the beam. The growth rate of instability and frequency excited oscillation is of the order of the reciprocal of the ion crossing time between the anode and cathode. In the limit of a uniform unperturbed state of plasma, the instability is analogous to the Pierce instability of an electron beam with the fundamental distinction that here, the perturbations are quasi-neutral. It is shown that the instability is alternately a periodical and oscillating depending on the range of the αlh parameter, which includes induction of the magnetic field (through lower hybrid frequency), thickness of the acceleration layer, and velocity of the ion flux.
Keywords :
anodes; numerical analysis; plasma devices; plasma hybrid waves; plasma instability; plasma magnetohydrodynamics; plasma oscillations; plasma-beam interactions; Hall thrusters; Pierce instability; acceleration layer thickness; anode; cathode; cold magnetized electrons; cold nonmagnetized ions; electron beam; electron inertia; ion beam instability; ion flux stability; ion flux velocity; lower hybrid frequency; magnetic field induction; numerical model; plasma oscillation; quasineutral perturbation; two-fluid magnetohydrodynamic approximation; Acceleration; Anodes; Boundary conditions; Equations; Ion beams; Oscillators; Plasmas; Boundaries; electrons; instability; ion flux; ions; quasi-neutral perturbations; two-fluid magnetohydrodynamic (MHD) approximation;
fLanguage :
English
Journal_Title :
Plasma Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0093-3813
Type :
jour
DOI :
10.1109/TPS.2014.2343452
Filename :
6899690
Link To Document :
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