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Thermal stability of the krypton Hall effect thruster

Szelecka A., Kurzyna J., Bourdain L.

Nukleonika

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2017

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Vol. 62, No. 1

9--15

EN

The Krypton Large IMpulse Thruster (KLIMT) ESA/PECS project, which has been implemented in the Institute of Plasma Physics and Laser Microfusion (IPPLM) and now is approaching its final phase, was aimed at incremental development of a ~500 W class Hall effect thruster (HET). Xenon, predominantly used as a propellant in the state-of-the-art HETs, is extremely expensive. Krypton has been considered as a cheaper alternative since more than fifteen years; however, to the best knowledge of the authors, there has not been a HET model especially designed for this noble gas. To address this issue, KLIMT has been geared towards operation primarily with krypton. During the project, three subsequent prototype versions of the thruster were designed, manufactured and tested, aimed at gradual improvement of each next exemplar. In the current paper, the heat loads in new engine have been discussed. It has been shown that thermal equilibrium of the thruster is gained within the safety limits of the materials used. Extensive testing with both gases was performed to compare KLIMT’s thermal behaviour when supplied with krypton and xenon propellants.

2

Advanced laboratory for testing plasma thrusters and Hall thruster measurement campaign

Szelecka A.

Nukleonika

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2016

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Vol. 61, No. 2

213--218

EN

Plasma engines are used for space propulsion as an alternative to chemical thrusters. Due to the high exhaust velocity of the propellant, they are more effi cient for long-distance interplanetary space missions than their conventional counterparts. An advanced laboratory of plasma space propulsion (PlaNS) at the Institute of Plasma Physics and Laser Microfusion (IPPLM) specializes in designing and testing various electric propulsion devices. Inside of a special vacuum chamber with three performance pumps, an environment similar to the one that prevails in space is created. An innovative Micro Pulsed Plasma Thruster (LPPT) with liquid propellant was built at the laboratory. Now it is used to test the second prototype of Hall effect thruster (HET) operating on krypton propellant. Meantime, an improved prototype of krypton Hall thruster is constructed.

3

Causality violation in analysis of Hall thruster plasma instabilities

Peradzyński Z., Barral S., Makowski K., Dudeck M.

Journal of Technical Physics

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2008

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Vol. 49, no 3-4

315-327

EN

Using the fluid equations of Hall thruster plasma we analyze the influence of the electron energy balance on the stability of ion sound modes. For sufficiently low frequencies (ω < 5 • 106^6 s-1 in the case of SPT-100) the gains and losses in the source term are approximately equal, thus the temperature can be in principle determined in terms of other dependent variables. This permits one to reduce the number of equations by one. It appears however, that the new system can have in some regions complex characteristics. This in turn implies instability of certain modes with frequencies lower than the critical frequency.

4

Bismuth Hall thruster II: Simulated diagnostics

Scharfe D. B., Capelli M. A.

Journal of Technical Physics

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2008

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Vol. 49, no 3-4

349-361

EN

A laboratory-model bismuth-fueled Hall thruster has been designed, and the geometry of that design has been incorporated into a 2-D radial-axial hybrid Hall thruster simulation. Velocity distribution data from the plume of that simulation, incorporated with calculations based on the known spectroscopy of the bismuth ion, have been used to simulate optical diagnostic measurements of the exhaust velocity of the thruster. Simulated Laser Induced Fluorescence ana emission spectroscopy data has been produced, assuming that the 14681.971 cm-1 transition of ionized bismuth is analyzed. The simulated Laser Induced Fluorescence assumes a narrow line-width, scanning laser probes the plasma either axially or radially, and it is suggested that the fluorescence be collected about the 15146.544 cm-1 transition; emission results have been simulated with varying instrument resolutions and with collection angles at 0° and 60° off the axial axis.

5

Bismuth Hall thruster I: Simulation-suggested design and performance

Scharfe D. B., Scharfe M. K., Capelli M. A., Fernandez E.

Journal of Technical Physics

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2008

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Vol. 49, no 3-4

329-348

EN

A two-dimensional radial-axial hybrid simulation of the xenon-fueled Stanford Hall Thruster has been adapted to model a bismuth-fed thruster with varying channel geometry. The simulation treats the electrons as a quasi-one-dimensional fluid and the neutrals and ions as discrete superparticles advanced using a particle-in-cell (PIC) approach. Since experimental data of the electron cross-field mobility does not exist for the bismuth-fueled thruster, a model for electron transport based on shear suppression of plasma turbulence is used to compute a mobility from simulated plasma properties. While the bismuth propellant showed poor performance with an 8 cm channel length, results improved significantly as the simulated channel was shortened to 3.3 and 2.4 cm. The simulation of bismuth propellant at the shortest channel length provided significantly improved ionization fraction, thrust, efficiency, and thrust-to-power compared to xenon propellant on either the 8 cm or 2.4 cm channel, as can be expected due to the higher atomic mass and lower ionization potential of bismuth. With results indicating that optimal performance of the bismuth thruster occurs with a sub-3 cm channel length, such a design is suggested for a developing laboratory-model bismuth thruster.