Electron cyclotron resonance (ECR) is currently under investigation as a method for ionization of residual atmospheric particles in air-breathing electric propulsion systems (ABEP). This technology for satellite propulsion is a subject of intense research because ABEP is a key enabling technology for accessing very low Earth orbits. The chosen method of ECR plasma investigation is a zero-dimensional global plasma model (GPM) capable of representing plasma by a system of nonlinear ordinary differential equations. The aim of the thesis is to develop and use a GPM describing ECR plasma to investigate the influence of external magnetic field on plasma confinement and extracted ion current. In cooperation with external partners, the student will perform laboratory experiments with the ECR ion system (ECRIS) capable of plasma ignition at low pressures in N2/O2 mixture. In particular, the student will measure the dependency of extracted ion current on a variable external magnetic field. The results will be correlated with the student's numerical simulation. The thesis will be completed in close collaboration with the company SpaceLabEU, who will provide access to the laboratory prototype of their ECRIS system, and PlasmaSolve, who will provide the simulation tools