The EP2 research group

We are a research team dedicated to the design, development, modeling, simulation, and testing of different space plasma thrusters. EP2 is part of the Aerospace Engineering Research group of the Bioengineering and Aerospace engineering department at Universidad Carlos III de Madrid.

Recent news

Research lines

Hall Effect Thruster

Hall Effect thruster

Hall Effect Thrusters (HET) are one of the most mature electric thrusters. They feature an annular geometry, with a magnetic circuit that generates a predominantly radial magnetic field inside the channel. By applying a voltage difference between the two ends of this channel, electrons are forced to follow closed drift orbits, thus ionizing a large amount of neutral atoms, before actually reaching the anode (at the propellant injection side). The reduced axial mobility of the electrons also produces a strong axial electric field that accelerates the ions. Our group has been active in modelling and understanding these thrusters for more than 2 decades, so that we have very advanced simulation tools, with which we plan to design and test a real HET in the near future.

Helicon Plasma thruster

Helicon plasma thruster

Helicon plasma thrusters (HPT) consist of a cylindrical plasma source where a neutral gas is ionized and heated using helicon waves, and a magnetic nozzle where the plasma is accelerated into a high velocity jet. They are robust and simple, as they do not have any naked electrodes in contact with the plasma. We model and simulate the plasma transport inside the helicon source and the plasma-wave interaction with the in-house HELFLU and HELWAVE codes. Recently, we have developed the HPT-05 prototype in collaboration with SENER Ingeneriería y Sistemas.

Magnetic Nozzles

Magnetic Nozzles

A magnetic nozzle is a convergent-divergent magnetic field that can be used to channel and accelerate a plasma jet supersonically to generate magnetic thrust. You can learn more about them in this video lecture. Their main advantages over solid nozzles are that they operate contactlessly, so that plasma-wall contact is avoided, and that they can be modified in shape and strenght during flight to gain, for example, thrust vector control capabilities without any moving parts. The DIMAGNO two-fluid code developed during my PhD thesis is a useful simulation tool. Recently, we have patented a 3D magnetic nozzle capable of steering the plasma jet in any direction.


Nanosatellites and Systems Engineering

Nanosatellites are game-changing spacecraft due to their reduced dimensions and cost. They are an affordable to test new technology in space, and to perform short missions of low to medium complexity. The NanoStar project aims to build a network of European universities to design, build, and launch nanosatellites with educational purposes. This line of work requires to have a broad, systems-level view of the nanosatellite, as well as a specialist understanding of the different subsystems of the spacecraft.

Active space debris removal

Active space debris removal

After more than 50 years of space operations, we have rendered our Low Earth Orbits (LEO) and Geostationary orbit (GEO) full of dead satellites, fragments, and upper stages. Dramatic collisional events have already taken place, and quite often the International Space Station (ISS) must perform debris-avoidance maneuvers to avoid a potential threat. In the FP7 LEOSWEEP project, we have studied an innovative means to tackle the space debris problem—the Ion Beam Shepherd (IBS). In this concept, a plasma plume is used to push contactlessly and efficiently a piece of debris to force its reentry into the atmosphere.

Plasma plumes and plasma-spacecraft interaction

Plasma plumes and plasma-spacecraft interaction

The operation of a plasma thruster creates an energetic plasma plume that expands into space. The peripheral part of this plume can contaminate and erode the exposed elements of the spacecraft, and affect its electrical charging state. These phenomena can become a serious issue in modern telecommunication satellites. Our two-fluid EASYPLUME code and the 3D hybrid PIC/FLUID EP2PLUS code have been developed to study plasma plumes and their interaction with the environment.

Plasma waves and ECR thruster

Plasma waves and ECR thruster

Electromagnetic waves behave very differently in a plasma compared to vacuum—many different types of waves can exist depending on their frequency, the plasma density, and the background magnetic field. Analogously to the helicon waves in the helicon plasma thruster, the electron-cyclotron resonance is an efficient heating mechanism that has been proposed for the design of a new type of plasma thruster—the ECR plasma thruster. In the frame of the H2020 MINOTOR project our group will develop a complete simulation framework for all the key processes in this device; the simulation of the plasma-wave phenomena has some synergies in both thrusters.

Faraday cup

Plasma diagnostics

In order to characterize experimentally the plasma of electric propulsion devices, it is necessary to develop precise plasma diagnostic tools. The EP2 group is active in both modelling and testing (experimentally) of Langmuir probes, emissive probes, Faraday cups, magnetic field sensors, thrust balances, etc...


Below you can find and download an updated list of the EP2 group journal publications, conference papers and doctoral theses.

Peer-reviewed publications

2018     2017     2016     2015     2014     2013     2012     2011     2010

Selected conference papers

2018     2017     2016     2015     2014     2013     2012     2011     2010

PhD theses


The EP2 group carries out advanced electric thruster research in a dedicated space plasma laboratory.

Our main vacuum chamber, of 1.5 m diameter and 3.5 m longitude, is equipped with the latest technology in terms of vacuum sensors and pumps and used to test electric propulsion prototypes and related technologies. A set of cryopanels and turbomolecular pumps provide more than 35000 l/s combined pumping velocity on Xe or Ar in an oil-free environment. We are currently developing and modeling different types of plasma probes, an automated 3D scanning system, and optical spectroscopy diagnostic techniques to support our experimental activities.

Plasma diagnostics and EP laboratory

Simulation tools

The EP2 group has developed, through its years of activity, a large suite of numerical simulation tools, that are detailed below.

Plasma plume neutralization


EP2PLUS (Extensible Parallel Plasma PLUme Simulator) is 3D hybrid PIC/fluid code, which treats the heavy particles (ions and neutrals) as macro-particles of a PIC sub-model, and the electrons as a fluid. A first version of the code has been developed during the LEOSWEEP project, but coding to add new simulation capabilities is an ongoing activity. Its main application is the study of the plasma plume expansion and neutralization into vacuum, and its interaction with the emitting satellite, or with any downstream object (as in the scenario of the ion beam shepherd technique).

Plasma plume density profile


EASYPLUME is a set of Matlab codes which enable a quick assessment of the properties of a plasma plume expanding rapidly into vacuum. Based on the Self-Similar and the Asymptotic Expansion methods, the codes are axisymmetric and have been used successfully in parametric studies like those of the electric propulsion subsystem optimization for an ion beam shepherd S/C (IBS). Such a study, in fact, required a fast estimation of plasma plume properties for a large set of initial conditions (radial profiles, initial divergence angle, electron temperature at the thruster exit, etc...)

HET plasma discharge with magnetic field lines


HYPHEN (HYbrid Plasma-thruster Holistic-simulation ENvironment) is a full 2D(r-z) hybrid PIC-Fluid code, capable of simulating time-resolved plasma discharges under the influence of magnetic fields. The plasma regime studied is characterized by the weak collisionality of the heavy-species populations, the strong magnetization of the electron population and a negligible self-field production by the plasma current. The characterization and partial validation of HYPHEN has been initially performed through the simulation of ion thruster plasma plumes, with ongoing efforts being centered on the simulation of complex Hall Effect Thruster discharges.


Eduardo Ahedo

Eduardo Ahedo (Professor)

Lines of work: Hall effect thrusters, RF-based plasma thrusters, magnetic nozzles, plasma plumes, plasma-wall interaction, plasma instabilities, active debris removal, electrodynamic tethers

Mario Merino

Mario Merino (Associate Professor)

Lines of work: Magnetized and un-magnetized plasma jet expansions, magnetic nozzles, plasma-wave interactions, and space debris active removal

Pablo Fajardo

Pablo Fajardo (Associate Professor)

Lines of work: Hall effect thrusters, hybrid PIC-fluid simulations, experimental characterization of plasma thrusters, plasma diagnostics, design of electric propulsion systems, fluid modeling

Jaume Navarro

Jaume Navarro Cavallé (Post-doc researcher)

Lines of work: theoretical, numerical and experimental plasmas for space propulsion, helicon and Hall effect thrusters, hollow cathodes

Filippo Cichocki

Filippo Cichocki (Post-doc researcher)

Lines of work: Plasma thruster plume interaction with the satellite, active debris removal, ion beam shepherd, magnetized and un-magnetized plasma plumes, hybrid PIC-fluid simulations

PhD thesis: Analysis of the expansion of a plasma thruster plume into vacuum.

Adrian Domínguez

Adrián Domínguez Vázquez (PhD student of the Spain's FPI scholarship program)

Lines of work: Hall effect thrusters, hybrid PIC-fluid simulations, full PIC simulations, plasma plumes

Xin Chen

Xin Chen (Juan de la Cierva Research Fellow)

Lines of work: Langmuir and emissive probe theory, electrodynamic tethers, thermionic Emission, hollow cathodes

Daniel Pérez Grande

Daniel Pérez Grande (Post-doc researcher)

Lines of work: Hall effect thrusters, hybrid PIC-fluid simulations

Jiewei Zhou

Jiewei Zhou (PhD student of the Spain's FPU scholarship program)

Lines of work: Helicon plasma thrusters, hybrid PIC-fluid simulations, magnetized plasmas plumes

Álvaro Sánchez Villar

Álvaro Sánchez Villar (PhD student of the PIPF scholarship of the Universidad Carlos III de Madrid)

Lines of work: Electron cyclotron resonance (ECR) plasma thrusters, waves in plasmas, ECR heating

Mick Wijnen

Mick Wijnen (PhD student of the PIPF scholarship of the Universidad Carlos III de Madrid)

Lines of work: plasma diagnostics (electrostatic probes, spectroscopy, thrust balance), helicon plasma thruster prototype testing and design (HPT05-M)

Sara Correyero

Sara Correyero (PhD student)

Lines of work: Electron cyclotron resonance ECR plasma thrusters, magnetic nozzles, thrust and plasma measurements


Universidad Carlos III de Madrid
Avda. de la Universidad 30
28911 Leganés (Madrid) Spain
Office: 7.1.H.14. View map
+34 91 624 8237
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