Simple model of plasma acceleration in a magnetic nozzle

Sercel, Joel C.

doi:10.2514/6.1990-2597

Cited by 18 publications

(12 citation statements)

References 2 publications

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“…Divergence angles were calculated for various radial distances, then averaged. The results of these estimates are consistent with predictions made for divergence angles by Kosmald (1967) and Sercel (1990).…”

Section: Electron Cyclotron Resonance (Ecr) Thrustersupporting

confidence: 91%

Electric thruster models for multimegawatt nuclear electric propulsion mission design

Leifer

Blandino

Sercel

1991

AIP Conference Proceedings

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Three types of electric thrusters currently under development at JPL have potential to support future missions which utilize multimegawatt nuclear elecUic propulsion. These electric thrusters are the electron bombardment ion thruster, the magnetoplasmadynamic (MID) thruster, and the electron-cyclotron-resonance (ECR) thruster. The electron bombardment ion thruster is a relatively mature technology which has been developed for operation at kilowatt power levels but will require new development for application in the multimegawatt regime. The MPD engine represents a technology which may be very well suited to steady-state multimegawatt applications but which has been limited to sub-scale (100's ofkW) and pulsed (MW) testing thus far. The ECR plasma engine represents a class of very promising new concepts which are still in the basic research phase of development, but which may possess important fundamental advantages over other electric thruster technologies. In this paper, models of these thrusters are described and used to make projections of thruster specific mass, efficiency, and power handling capacity for operation in the multimegawatt regime.

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Section: Electron Cyclotron Resonance (Ecr) Thrustersupporting

confidence: 91%

Electric thruster models for multimegawatt nuclear electric propulsion mission design

Leifer

Blandino

Sercel

1991

AIP Conference Proceedings

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“…Pressure anisotropy, with different parallel and perpendicular temperatures, is of interest for certain plasma thrusters, in particular the electrodeless electron cyclotron resonance thruster. 11,27 Non-isothermality and anisotropy are dominant (i.e., zero-Larmor-radius) effects on the electron response and require an independent study.…”

Section: B On Full Felr Effectsmentioning

confidence: 99%

“…Since his model has been the basis for other works, [11][12][13][14] yielding inwards plasma separation too, a discussion of Hooper's model is very pertinent here. Hooper's model is similar to ours except for two important features, which are at the core of the disagreement with our conclusions: his model imposes current ambipolarity everywhere and is limited to the expansion of a cold plasma.…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional plasma expansion in a magnetic nozzle: Separation due to electron inertia

Ahedo

Merino

2012

Physics of Plasmas

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A previous axisymmetric model of the supersonic expansion of a collisionless, hot plasma in a divergent magnetic nozzle is extended here in order to include electron-inertia effects. Up to dominant order on all components of the electron velocity, electron momentum equations still reduce to three conservation laws. Electron inertia leads to outward electron separation from the magnetic streamtubes. The progressive plasma filling of the adjacent vacuum region is consistent with electron-inertia being part of finite electron Larmor radius effects, which increase downstream and eventually demagnetize the plasma. Current ambipolarity is not fulfilled and ion separation can be either outwards or inwards of magnetic streamtubes, depending on their magnetization. Electron separation penalizes slightly the plume efficiency and is larger for plasma beams injected with large pressure gradients. An alternative nonzero electron-inertia model [E. Hooper, J. Propul. Power 9, 757 (1993)] based on cold plasmas and current ambipolarity, which predicts inwards electron separation, is discussed critically. A possible competition of the gyroviscous force with electron-inertia effects is commented briefly. V C 2012 American Institute of Physics. [http://dx

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“…Other numerical studies have identified specific aspects of behavior within magnetic nozzle effects. 1,18,19 Identifying the "frozen-in" condition, Winglee et al 1 recognized the self-collimation of the plasma plume as well as the stretching tendency of magnetic field lines. Similar conclusions were drawn by Arefiev and Breizman.…”

Section: Introductionmentioning

confidence: 99%

Modeling of plasma processes in the slowly diverging magnetic fields at the exit of an applied-field magnetoplasmadynamic thruster

Tang

Ren

et al. 2013

Physics of Plasmas

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The performance of plasma thrusters with applied electric and magnetic fields can be enhanced by increasing the magnetic field strength, which is applied in the thrust chamber and the exit region propulsive plume. The ejected plasma which passes through a slowly diverging magnetic field will expand but can be restricted within the magnetic nozzle fields. To examine in detail the processes that occur, a new method with Particle-in-cell calculations is applied here. A two-dimensional axisymmetric particle dynamic code is used to model an AF-MPDT (Applied-field Magnetoplasmadynamic Thruster) for which extensive experimental data are available; it used Ar propellant and had applied magnetic coils of 101.5 mm radius and 153 mm length. From the results of the simulation study, it is found that total thrust increases linearly with magnetic field strength in the range of 0-0.1 T, but it decreases with increasing applied magnetic field up to 0.6 T. Thrust efficiency is found to increase to a maximum of 8.4% when B ¼ 0.1 T; further, the peak value of nozzle efficiency reaches 91% at a moderate magnetic field (0.3 T). In detail, it is found that distributions of plasma density (10 14 -10 15 m À3 ) that form in the magnetic nozzle demonstrate a significant pattern of concentration up to fields of B ¼ 0.3 T where ions begin to be magnetized. However, azimuthal velocities of ions behave differently with different degrees of magnetization, i.e., weakly magnetized ions follow rotating electrons in a right-handed direction, while fully magnetized ions revolve in left-handed direction due to electromagnetic forces. Notably, a feedback effect on total magnetic field due to plasma motion identified in other studies is not found to be present in the working conditions of the AF-MPDT examined here. V C 2013 AIP Publishing LLC.

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Simple model of plasma acceleration in a magnetic nozzle

Cited by 18 publications

References 2 publications

Electric thruster models for multimegawatt nuclear electric propulsion mission design

Electric thruster models for multimegawatt nuclear electric propulsion mission design

Two-dimensional plasma expansion in a magnetic nozzle: Separation due to electron inertia

Modeling of plasma processes in the slowly diverging magnetic fields at the exit of an applied-field magnetoplasmadynamic thruster

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