Analysis of the expansion of a plasma thruster plume into vacuum

• Autores: Filippo Cichocki
• Directores de la Tesis: Eduardo Ahedo Galilea (dir. tes.), Mario Merino Martínez (codir. tes.)
• Lectura: En la Universidad Carlos III de Madrid ( España ) en 2017
• Idioma: español
• Tribunal Calificador de la Tesis: Mª. Victoria Lapuerta González (presid.), Luis Raul Sánchez Fernández (secret.), Francesco Taccogna (voc.)
• Programa de doctorado: Programa de Doctorado en Plasmas y Fusión Nuclear por la Universidad Carlos III de Madrid
• Materias:
  • Física
    • Física de fluidos
      • Física de plasmas
• Enlaces
  • Tesis en acceso abierto en: e-Archivo
• Resumen

  • The analysis of the interaction between a plasma plume and a satellite is gradually becoming a very demanded task in the space industry, given the increasing use of electric propulsion. In fact, the plasma plumes generated by the electric thrusters can damage sensitive spacecraft components, such as the solar arrays or onboard optical sensors. Moreover, plasma plumes can be used to one's benefit in the context of the ion beam shepherd technique for space debris removal, in which a shepherd spacecraft relocates a debris object to a different orbit, by directing towards it a plasma plume, at an operational distance of several meters.

    This thesis focuses on the numerical study of the expansion of a plasma thruster plume into vacuum and its interaction with the satellite and any downstream object. Two simulation codes have been developed.

    The first code, named EASYPLUME, is based on an axisymmetric two-fluid plasma plume model and allows to quickly estimate the plasma plume properties farther downstream. With this code the physics of the plume expansion has been investigated, understanding its dependence on the most important plume parameters, such as the divergence angle, the ion Mach number, and the electron cooling rate. Moreover, the code has been used in the context of the ion beam shepherd technique to estimate the force transmission to a space debris object, and optimize the overall electric propulsion subsystem of the shepherd spacecraft.

    The second code, named EP2PLUS, is a three-dimensional hybrid particle-in-cell/fluid code that simulates the complex interaction between a plasma plume, the spacecraft and other objects. The most relevant modeling novelties regard the electron model, which enables the computation of the electric currents in the plume, and the treatment of quasineutral and non-neutral plasma regions. This code has been applied to study both the satellite-plume interaction and a reference ion beam shepherd scenario. In the latter, several operational problems have been evaluated: the ion backscattering towards the shepherd satellite, the sputtering of the debris object (due to the impingement of hypersonic ions), the backsputtering contamination of the spacecraft, and the electric charging of both the satellite and the target debris.

    Finally, the report of an experimental campaign, carried out during my PhD visit at the ``Laboratoire de Physique des Plasmas'' (Paris) and aiming at characterizing the plasma plume of the PEGASES plasma thruster, completes this work.