Numerical and theoretical modeling of wave turbulence in partially-magnetized plasmas (M/F)

Job Description

Thesis Subject

Satellite electric propulsion is a technology that works with low temperature plasmas. Some thruster technologies, such as the Hall thrusters, use a low-pressure partially-magnetized plasma, characterized by electrons that are magnetized whereas the ion Larmor radius remains larger than the typical length of the system. Under these low-pressure conditions, the plasma can host different electrostatic instabilities [1], e.g., gradient-drift, lower-hybrid, electron cyclotron drift, modified two-stream, etc. These instabilities can lead to wave turbulence, which modifies the macroscopic properties of the discharge (e.g., the electric current, plasma density, etc). For this reason, a better understanding of the wave turbulence is fundamental for the characterization of ExB plasmas.

This thesis is aimed at the theoretical and numerical study of the wave turbulence under partially-magnetized plasmas for electric propulsion. The thesis will develop new reduced model of equations that will capture the main modes that are observed in these plasmas and will be implemented in a numerical code. In addition, the closure problem will be investigated in order to study the transport fluxes that are consequence of this turbulence.

Refs.

[1] F. Petronio, T. Charoy, A. Alvarez Laguna, A. Bourdon, and P. Chabert, 'Two-dimensional effects on electrostatic instabilities in Hall thrusters. I. Insights from particle-in-cell simulations and two-point power spectral density reconstruction techniques', Phys. Plasmas, vol. 30, no. 1, p. 012103, Jan. 2023, doi: 10.1063/5.0119253.
[2] F. Petronio, A. Alvarez Laguna, A. Bourdon, and P. Chabert, 'Study of the breathing mode development in Hall thrusters using hybrid simulations', J. Appl. Phys., vol. 135, no. 7, p. 073301, Feb. 2024, doi: 10.1063/5.0188859.
[3] T. Charoy, T. Lafleur, A. A. Laguna, A. Bourdon, and P. Chabert, 'The interaction between ion transit-time and electron drift instabilities and their effect on anomalous electron transport in Hall thrusters', Plasma Sources Sci. Technol., vol. 30, no. 6, p. 065017, Jun. 2021, doi: 10.1088/1361-6595/ac02b3.
[4] T. Charoy et al., '2D axial-azimuthal particle-in-cell benchmark for low-temperature partially magnetized plasmas', Plasma Sources Sci. Technol., vol. 28, no. 10, p. 105010, Oct. 2019, doi: 10.1088/1361-6595/ab46c5.
[5] F. Petronio, T. Charoy, A. Alvarez Laguna, A. Bourdon, and P. Chabert, 'Two-dimensional effects on electrostatic instabilities in Hall thrusters. II. Comparison of particle-in-cell simulation results with linear theory dispersion relations', Phys. Plasmas, vol. 30, no. 1, p. 012104, Jan. 2023, doi: 10.1063/5.0119255.

Your Work Environment

Our society is increasingly dependent on the operation of satellites. They play an integral part in many of our daily-life activities: GPS navigation, telecommunications, weather forecasting, environmental monitoring and disaster management, agriculture, etc. Since 2020, we have experienced a revolution, characterized by a dramatic increase in the number of launches of small satellites. These missions are increasingly complex, requiring a propulsion system in the satellite to control its trajectory in a durable, accurate and reliable manner.

In the Laboratoire de Physique des Plasmas (LPP), two types of EP thrusters are studied: the gridded-ion thruster PEGASES and the Hall thruster. The first consists of a device designed to ionize a gas and then accelerate the ions thus formed via a potential drop applied to a metallic grid. The second uses a magnetic field to trap the electrons that will ionize the injected gas, thus increasing the residence time in the thruster. In both thrusters, the magnetic field is used in order to trap the electrons, increasing their residence time and changing the plasma transport. In PEGASES, the magnetic trap is used in order to create an ion-ion electronegative plasma, whereas in the Hall thruster, the magnetic field is used in order to reduce the axial conductivity of the plasma, increasing the electric field and the electron-impact ionization (see Fig. 1 for a sketch of the thrusters studied at LPP).

This project will be developed in the frame of a European Research Council (ERC) Grant. This 5-year project will develop novel mathematical methods for the numerical study of electric propulsion thrusters. In addition, the thesis takes advantage of the research environment of LPP, proposing a collaboration between the low-temperature plasma and the fusion plasma teams.

Constraints and risks

N/A

Compensation and benefits

Compensation

2300 € gross monthly

Annual leave and RTT

44 jours

Remote Working practice and compensation

Pratique et indemnisation du TT

Transport

Prise en charge à 75% du coût et forfait mobilité durable jusqu’à 300€

About the offer

About the CNRS

The CNRS is a major player in fundamental research on a global scale. The CNRS is the only French organization active in all scientific fields. Its unique position as a multi-specialist allows it to bring together different disciplines to address the most important challenges of the contemporary world, in connection with the actors of change.

CNRS

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