A Reduced-Order Model for Thermionic Hollow Cathodes

Albertoni, Riccardo; Pedrini, Daniela; Paganucci, Fabrizio; Andrenucci, Mariano

doi:10.1109/tps.2013.2266512

Cited by 34 publications

(48 citation statements)

References 35 publications

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“…Figure (19) shows the NSTAR neutralizer cathode internal pressure values predicted by the model. Insert lifetime has a decreasing tendency with both discharge current and mass flow rate as seen in Figure (21) which is consistent with lifetime result of the Alta model [19]. This higher pressure prediction can be explained by the model's overestimation of the orifice wall temperature for NSTAR cathode.…”

Section: Resultssupporting

confidence: 80%

“…Especially, operation at high currents and mass flow rates pushes the plasma density peak to the regions closer to orifice [26], [27], [28]. It is assumed that the product of the effective emission length and the insert plasma pressure is equal to 15 mPa [19]. As a result of this small plasma-emitter attachment area, required current is emitted from that small region close to the orifice which leads to high current density and high temperature as speculated in studies [15], [27], [29].…”

Section: Fig 2 Mobility Of Ions In the Emitter Regionmentioning

confidence: 99%

“…In the model, it is assumed that the heavy particles, namely neutrals and ions, have the same temperature with the cathode wall. The developed model follows the previous studies of different researchers [15], [18], [19]. Ion conservation and plasma energy balance equations are solved with an iterative procedure until current balance equation written for insert plasma and surface energy balance written for orifice wall are satisfied.…”

Section: Hollow Cathode Global Modelmentioning

confidence: 99%

“…For determination of the effective emission length of the insert, the simple methodology proposed by Alta group is used. It is assumed that the product of the effective emission length and the insert plasma pressure is equal to 15 mPa [19].…”

Section: Fig 2 Mobility Of Ions In the Emitter Regionmentioning

confidence: 99%

“…The reference geometry modelled in this study is adopted from [19] and is shown in Figure (5). Basically, there are three main geometric parameters that are associated with the hollow cylindrical insert: the inner diameter, D in = 3 mm, the outer diameter, D out = 6.9 mm, and the length, L ins = 6 mm.…”

Section: Solution Of Model Equationsmentioning

confidence: 99%

See 4 more Smart Citations

Global Numerical Model for the Assessment of the Effect of Geometry and Operation Conditions on Insert and Orifice Region Plasmas of a Thermionic Hollow Cathode Electron Source

Korkmaz

Çelik

2014

Contrib. Plasma Phys.

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Thermionic hollow cathodes have been widely used in wide variety of areas such as spacecraft electric propulsion systems, material processing and lasers for more than half a century as efficient electron sources. Especially in electric propulsion systems, hollow cathodes are being used as electron sources for propellant ionization and ion beam neutralization. Moreover, it is also a promising candidate for utilization as a stand-alone propulsion system in microsatellites or nanosatellites due to its small physical size, low power consumption and ease of operation. On the other hand, the small geometry of the typical orificed hollow cathodes makes the plasma diagnostics difficult which is why numerical studies become important for understanding the driving physical processes behind their operation, and the effects of the geometry and the operation parameters on cathode performance. In this paper, a global numerical model for the insert and orifice plasma of a hollow cathode is presented where volume averaged plasma parameters are considered for both regions. The results of this study show that the developed model can be used for designing and sizing orificed hollow cathodes as comparisons with the results of experimental and other numerical studies are in good agreement with the ones obtained from the developed model.

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Section: Resultssupporting

confidence: 80%

Section: Fig 2 Mobility Of Ions In the Emitter Regionmentioning

confidence: 99%

Section: Hollow Cathode Global Modelmentioning

confidence: 99%

Section: Fig 2 Mobility Of Ions In the Emitter Regionmentioning

confidence: 99%

Section: Solution Of Model Equationsmentioning

confidence: 99%

See 3 more Smart Citations

Global Numerical Model for the Assessment of the Effect of Geometry and Operation Conditions on Insert and Orifice Region Plasmas of a Thermionic Hollow Cathode Electron Source

Korkmaz

Çelik

2014

Contrib. Plasma Phys.

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Development and Validation of Simplified 1D Models for Hollow Cathode Analysis and Design

Panelli

Smoraldi

Simone

et al. 2018

Aerotec. Missili Spaz.

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Design of a hollow cathode thruster: concepts, parameter study and initial test results

Gondol

2021

CEAS Space J

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Two electric propulsion concepts have been developed at Technische Universität Dresden as spin-off devices of regular hollow cathodes and initial testing has been conducted. Both devices represent millinewton thrusters that take advantage of thermionic electron emission using the low work function materials C12A7, LaB6, and thoriated tungsten in different design configurations. The first concept represents an electrothermal thruster which generates thrust by expanding and accelerating a heated propellant in a nozzle. Initial thrust measurement tests were carried out which showed thrust levels well above cold gas thrust, but low thrust efficiencies. The influence of different geometric parameters on the discharge properties and the performance is investigated and presented. The second thruster concept is a novel electromagnetic device in which charge carriers in a plasma discharge are accelerated by an applied magnetic field that is orthogonally oriented to the discharge current. Initial tests with C12A7 were not successful, but the functionality of the concept was shown by thrust measurements using a thoriated tungsten wire as an electron emitter.

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A Reduced-Order Model for Thermionic Hollow Cathodes

Cited by 34 publications

References 35 publications

Global Numerical Model for the Assessment of the Effect of Geometry and Operation Conditions on Insert and Orifice Region Plasmas of a Thermionic Hollow Cathode Electron Source

Global Numerical Model for the Assessment of the Effect of Geometry and Operation Conditions on Insert and Orifice Region Plasmas of a Thermionic Hollow Cathode Electron Source

Development and Validation of Simplified 1D Models for Hollow Cathode Analysis and Design

Design of a hollow cathode thruster: concepts, parameter study and initial test results

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