On a similarity criterion for plasma accelerators of the stationary plasma thruster type

Bugrova, A. I.; Lipatov, A. S.; Морозов, А. И.; Чурбанов, Д. В.

doi:10.1134/1.1519018

Cited by 23 publications

(15 citation statements)

References 1 publication

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“…Bugrova et al [17] derives a similarity criterion, S, to ensure optimum propellant ionization from a zero-dimensional model. S can be expressed by the following formula: According to the Maslennikov-Morozov criterion [18], the mass flow rate range, achieving optimum propellant ionization at a certain discharge condition, can be obtained as follows:…”

Section: Resultsmentioning

confidence: 99%

Effect of low-frequency oscillation on performance of Hall thrusters

Wei¹,

LI²,

Ding³

et al. 2018

Plasma Sci. Technol.

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In this paper, a direct connection between the discharge current amplitude and the thruster performance is established by varying solely the capacitance of the filter unit of the Hall thrusters. To be precise, the variation characteristics of ion current, propellant utilization efficiency, and divergence angle of plume at different low-frequency oscillation amplitudes are measured. The findings demonstrate that in the case of the propellant in the discharge channel just meets or falls below the full ionization condition, the increase of low-frequency oscillation amplitude can significantly enhance the ionization degree of the neutral gas in the channel and increase the thrust and anode efficiency of thruster. On the contrary, the increase in the amplitude of low-frequency oscillation will lead to increase the loss of plume divergence, therefore the thrust and anode efficiency of thruster decrease.

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Section: Resultsmentioning

confidence: 99%

Effect of low-frequency oscillation on performance of Hall thrusters

Wei¹,

LI²,

Ding³

et al. 2018

Plasma Sci. Technol.

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“…Experimental parameter E 2 relates the input flow of mass to the total output flow of charge. The inverse of E 2 was used in the Soviet literature [50] as early as 1978 and termed the exchange parameter [51,52]. The naming convention adopted here describes the exchange of applied input parameters to operational thruster properties.…”

Section: E Evaluating Exchange Parameters and Thruster Performancementioning

confidence: 99%

Methodology and Historical Perspective of a Hall Thruster Efficiency Analysis

Brown

Larson

Beal

et al. 2009

Journal of Propulsion and Power

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A Hall thruster performance architecture was developed based on separation of the total thrust directed along thruster centerline into mass-weighted and momentum-weighted terms. With this formulation, the total thruster efficiency equation was analytically decomposed to explicitly account for the effects of energy conversion losses, plume divergence, and the velocity distribution function of the propellant jet. Thruster efficiency is defined as the product of 1) energy efficiency, 2) propellant efficiency, and 3) beam efficiency. Energy efficiency comprises losses due to ionization processes and losses that manifest as Joule heating, and contains no information about the vector properties of the jet. Propellant efficiency incorporates losses from dispersion in the jet composition and is unity for 100% ionization to a single ion species. The effect of neutrals on dispersion of the jet velocity distribution function in propellant efficiency is introduced in the neutral-gain utilization. The beam efficiency accounts for divergence of the jet and is ideal when the ion velocity vectors are parallel to the thrust axis. Plume divergence is defined as a momentum-weighted term, and the approximation as a charge-weighted term is characterized. The efficiency architecture is derived from first principles and is applicable to all propulsion employing electrostatic acceleration, including Hall thrusters and ion thrusters. Distinctions and similarities to several past methodologies are discussed, including past ion thruster analyses, early Russian performance studies, and contemporary architectures. To illustrate the potential for enhanced understanding of loss mechanisms and ionization processes with an array of farfield plume diagnostics, a case study is presented of low-discharge voltage operation from a 6 kW laboratory Hall thruster. Nomenclature A = spherical shell surface area element in the plume E 1 = voltage exchange parameter E 2 = mass exchange parameter F = thrust density vector in the plume F = Faraday constant, 96; 485 C=mol of charge f j = normalized ion mass flow fraction of jth ion species fv = velocity distribution function of ions and neutrals g = Earth's gravitational constant at sea level, 9:806 m=s 2 I Axial = axial component of beam current parallel to thruster centerline I Beam = integrated beam current I d = anode discharge current I sp = total specific impulse J = current density in the plume at angular position j = propellant charge state index, 0, 1, 2, 3, etc., for Xe 0 , Xe 1 , Xe 2 , Xe 3 M = molecular weight of propellant, Xe 0:1313 kg=mol _ m i = mass flow rate of ions, where P _ m j _ m i for j 1 to the jth ion species _ m j = mass flow rate of jth species _ m T = total mass flow rate to the anode and cathode, where P _ m j _ m T for j 0 to the jth ion species _ m = mass flux at angular position P d = discharge power to the anode P jet = jet power P loss = power lost to Joule heating processes P min = minimum power required to sustain ionization Q = average charge of propellant ions R = downst...

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“…Examining equation (2) indicates that a longer channel length (or longer ionization region as pointed out in subsequent works [25,26]) should be used due to the higher ion and neutral velocities associated with the lower atomic mass of magnesium. The maximum ionization cross section of magnesium is larger than that of xenon by almost a factor of two, however, the ionization cross section for magnesium peaks at lower electron temperaturesaround 10 eV-and decreases rapidly as the electron temperature continues to increase [27][28][29].…”

Section: Comparison Of Magnesium To Xenon Performance and Discusmentioning

confidence: 99%

Performance Comparison between a Magnesium- and Xenon-fueled 2 kW Hall Thruster

Hopkins¹,

King²

2014

50th AIAA/ASME/SAE/ASEE Joint Propulsion Conference

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The performance metrics of a 2-kW-class thruster operated using magnesium propellant was measured and compared to the performance of the same thruster operated using xenon propellant. It was found that the magnesium thruster has thrust ranging from 34 mN at 200 V to 39 mN at 300 V with 1.7 mg/s of propellant. It was found to have 27 mN of thrust at 300 V using 1.0 mg/s of propellant. The thrust-to-power ratio ranged from 24 mN/kW at 200 V to 18 mN/kW at 300 volts. The specific impulse was 2000 s at 200 V and upwards of 2700 s at 300 V. The anode efficiency was found to be ~23% using magnesium which is substantially lower than the 40% anode efficiency of xenon at approximately equivalent molar flow rates. A comparison of the angular ion current distribution in the plasma beam revealed that the magnesium-fueled thruster has a much larger beam divergence than the xenon-fueled thruster.

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On a similarity criterion for plasma accelerators of the stationary plasma thruster type

Cited by 23 publications

References 1 publication

Effect of low-frequency oscillation on performance of Hall thrusters

Effect of low-frequency oscillation on performance of Hall thrusters

Methodology and Historical Perspective of a Hall Thruster Efficiency Analysis

Performance Comparison between a Magnesium- and Xenon-fueled 2 kW Hall Thruster

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