A collisionless plasma thruster plume expansion model Articles uri icon

publication date

  • April 2015

issue

  • 3 (035006)

volume

  • 24

international standard serial number (ISSN)

  • 0963-0252

electronic international standard serial number (EISSN)

  • 1361-6595

abstract

  • A two-fluid model of the unmagnetized, collisionless far region expansion of the plasma plume for gridded ion thrusters and Hall effect thrusters is presented. The model is integrated into two semi-analytical solutions valid in the hypersonic case. These solutions are discussed and compared against the results from the (exact) method of characteristics; the relative errors in density and velocity increase slowly axially and radially and are of the order of 10-2-10-3 in the cases studied. The plasma density, ion flux and ambipolar electric field are investigated. A sensitivity analysis of the problem parameters and initial conditions is carried out in order to characterize the far plume divergence angle in the range of interest for space electric propulsion. A qualitative discussion of the physics of the secondary plasma plume is also provided.

keywords

  • Plasma plumes; self-similar models; cold plasma; plasma expansion; fluid models