Programa del congreso

ERMES 20.0 is the latest release of an open-source C++ finite element software designed to solve Maxwell's equations in the frequency domain. This version introduces new features, modules, and finite element formulations to address the complex challenges commonly encountered in the design and analysis of electromagnetic systems. Examples of ERMES 20.0 applications are: bio-electromagnetics, electrostatic discharges, electromagnetic compatibility, microwave engineering, and plasma-wave interactions. This paper highlights the key advancements in ERMES 20.0, detailing its new capabilities and demonstrating its potential to help in the numerical modeling and analysis of electromagnetic design problems.

The operation of various types of space plasma thrusters relies on heating the plasma with electromagnetic waves, typically in the MHz or GHz range. This is the case of electrodeless plasma thrusters.

To understand and characterize the propagation and absorption of electromagnetic power by the magnetoplasma, a commonly-used approach is to model the plasma as a linear, anisotropic, gyrotropic, dissipative medium based on the cold-plasma assumption.

Simulation codes ranging from finite differences (e.g. Yee scheme) to finite elements (e.g. Nédélec edge elements) are used to find the response of the wavefields to a given geometry, plasma density, and applied magnetic field profiles.

This presentation reviews recent efforts at Universidad Carlos III de Madrid to simulate electrodeless plasma thrusters with finite element schemes, and the occurrence of spurious wave solutions whenever the propagation regime includes so-called resonant cones. To characterize the spurious solutions, we set up a verification simulation case based on the Fresnel problem for a planar wave propagating in vacuum and into a plasma, and compare against the analytical solution. We find perfect agreement with our finite element solution, except for parametric regimes where the plasma has resonant cones.

Analysis of the analytical and numerical dispersion relations helps identify the sources of error, and potential countermeasures are proposed.

The study of electromagnetic waves propagation and plasma-wave coupling is a central aspect for the understanding of plasma thrusters performances, especially those driven by the excitation of radiofrequency waves, such as the Helicon Plasma Thruster. This work presents the design of a B-dot probe and its use for the characterization of the electromagnetic field patterns along the plasma plume ejected by a 450 W class helicon plasma thruster breadboard. The wave propagation results will be correlated with the thruster performances for a set of different operating conditions.