EP2 Research Group

The Plasma & Space Propulsion Team (EP2)

We are a research group dedicated to the modeling, simulation, design, development, and testing of space plasma thrusters and related subjects. EP2 is part of the Aerospace Engineering Department at Universidad Carlos III de Madrid.

Research lines

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.

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.

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.

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

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.

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...

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.

St3llar

EP2 also participates in ST3LLAR, the joint Space Technology Research Laboratory of SENER Aeroespacial and UC3M.

Research projects

ZARATHUSTRA: Revolutionizing advanced electrodeless plasma thrusters for space transportation (2021–2025)

European Research Council, ERC-Starting Grant program. Grant number: 950466. Principal Investigator: Mario Merino.

ASPIRE: Advanced Space Propulsion for Innovative Realization of space Exploration (2021–2023)

H2020 Programme (European Commission). Grant number: 101004366. Principal Investigator: Eduardo Ahedo

ESPEOS: Electric Space Propulsion for Earth Orbit Satellites (2020–2022)

Ministry of Science and Innovation, National I+D plan, Spanish Government. Grant number: PID2019-108034RB-I00. Principal Investigators: Mario Merino, Pablo Fajardo.

Plasma Propulsion and Nuclear Fusion: innovating space transport (2019–2021)

Comunidad Autónoma de Madrid (CAM). Grant number: Y2018/NMT4750. Principal Investigator: Eduardo Ahedo.

Electric propulsion diagnostic for plasma thrusters (2021–2022)

SENER Aeroespacial S.A. Principal Investigator: Jaume Navarro.

CHEOPS: Consortium for Hall Effect Orbital Propulsion System – Phase 2 covering LOW POWER and MEDIUM POWER needs (2021-2024)

H2020 Programme (European Commission). Grant number: 101004331. Principal Investigator: Pablo Fajardo, Eduardo Ahedo. Project Manager: SAFRAN-Snecma (France).

EDDA: European Direct-Drive Architecture (2019–2021)

H2020 Programme (European Commission). Grant number: 870470. Principal Investigator: Eduardo Ahedo. Project Manager: Thales Alenia Space (France).

Click here for the final version of EDDA leaflet

ECOMODIS: Electron cooling model for simulation of ep induced plasma interactions with satellites (2022–2024)

European Space Agency (ESA). Grant: 4000137869. Principal Investigator: Pablo Fajardo, Eduardo Ahedo.

COMIT: COmpact MIni plasma Thruster for New Space applications (2021–2023)

Ministry of Science and Innovation, National I+D plan, Spanish Government. Grant number: PDC2021-120911-I00. Principal Investigator: Eduardo Ahedo, Pablo Fajardo.

SUPERLEO: Sustainable propellants enabling plasma propulsion at very low Earth orbit (2022–2024)

Grant TED2021-132484B-I00 funded by MCIN/AEI/10.13039/501100011033 and by the “European Union NextGenerationEU/PRTR. Principal Investigator: Jaume Navarro, Pablo Fajardo.

EXOPLAWIN: Estudio de la interacción del viento estelar con magnetosferas exo-planetarias mediante fuentes de plasma artificial y modelos computacionales (2022–2023)

Comunidad Autónoma de Madrid (CAM). Grant: EXOPLAWIN-CM-UC3M. Principal Investigator: Jaume Navarro, Jacobo Varela.

HIPATIA: Helicon Plasma Thruster for In-space Applications (2019–2022)

H2020 Programme (European Commission). Grant number: 870542. Principal Investigator: Pablo Fajardo. Project Manager: SENER Aerospace (Spain).

MARTINLARA: Millimeter wave Array at Room Temperature for INstruments in Leo Altitude Radio Astronomy (2019-2022)

Comunidad Autónoma de Madrid (CAM). Grant: P2018/NMT-4333. Principal Investigator: Eduardo Ahedo.

Publications

Below you can find and download an updated list of the EP2 group journal publications, conference papers and doctoral theses. In compliance with the European Commission regulations, all EP2 scientific publications can be accessed through the institutional UC3M e-Archive (green open access)

Peer-reviewed publications

Selected conference papers

PhD theses

2025 International Electrodeless Plasma Thruster workshop

The 2025 International EPT Workshop brings together researchers and experts from the plasma propulsion community to discuss the latest developments in Electrodeless Plasma Thrusters. Please stay tuned, as more information will be uploaded to this page soon. For inquiries, please contact Mario. Workshop materials will be accessible on this website.

EPT Workshop 2025

Laboratory

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.

Simulation tools

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

EP2PLUS

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).

EASYPLUME

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...)

DIMAGNO

DIMAGNO DIMAGNO is a two-fluid code for the simulation of DIvergent MAgnetic NOzzles for next generation plasma thrusters (Helicon Plasma Thruster, Electron-Ciclotron Plasma Thruster, Applied-Field MPD thruster, VASIMR, etc). It uses the method of characteristics to integrate the supersonic ion equations. The full version of DIMAGNO was developed since 2009 by Mario Merino and Eduardo Ahedo, and has been used extensively to research the operation and the physics of the plasma flow in a magnetic nozzle. The full description of the model can be found in E. Ahedo and M. Merino, "Two-dimensional supersonic plasma acceleration in a magnetic nozzle", Physics of Plasmas 17, 073501 (2010).

HET plasma discharge with magnetic field lines

HYPHEN

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.

Akiles2D

Akiles2D (Advanced Kinetic Iterative pLasma Expansion Solver 2D) is the Matlab implementation of the kinetic plasma plume model described in M. Merino et al., "Kinetic electron model for plasma thruster plumes," Plasma Sources Science and Technology 27, 035013 (2018). The code allows to compute the electric potential and the electron distribution function in a paraxial, collisonless plume and compute any moment of the distribution function. The name Akiles2D stands for "Advanced Kinetic Iterative pLasma Expansion Solver 2D." The first version of this code has been funded by ESA under contract 4000116180/15/NL/PS. It has been developed by Mario Merino and Javier Mauriño, the latter during a research visit to the EP2 group at UC3M, funded by a UK Royal Academy of Engineering Engineering Leaders Scholarship (ELAA1516/1/87). Akiles2d solves iteratively for the electric potential and the EVDF weight in a paraxial, unmagnetized, steady-state plasma plume to satisfy quasineutrality and a global condition on the net electric current. It can be readily used for magnetized plumes in magnetic nozzles as well. After successful convergence to the self-consistent solution, the Akiles2d c omputes the most frequently used moments of the ion and electron distribution functions. Currently, only the radially-parabolic electric potential and the semi-Maxwellian electron distribution upstream are implemented, but the code is structured to allow easy extension to other cases.

Personnel

Faculty

Eduardo Ahedo (Full Professor)

Research lines: Modeling and simulation of plasma propulsion technologies: Hall effect thrusters, ion thrusters, electrodeless plasma thrusters and magnetic nozzles. Plasma plumes: expansion and interaction with objects. Basic phenomena: instabilities, kinetic description, wall interaction.

Mario Merino (Full Professor)

Research lines: Magnetized and un-magnetized plasma jet expansions, magnetic nozzles, plasma-wave interactions, and space debris active removal

Pablo Fajardo (Full Professor)

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

Jaume Navarro Cavallé (Associate Professor)

Research lines: Development and validation of plasma thrusters (Helicon, ECR, Hall). Design of plasma diagnostics

Jiewei Zhou (Assistant Professor)

Research lines: Helicon plasma thrusters, hybrid PIC-fluid simulations, magnetized plasmas plumes

Alberto Marín Cebrián (Assistant Professor)

Research lines: Hall effect thrusters, full PIC simulations and plasma-wall interaction

Ahilan Appar (Assistant Professor)

Research lines: Hypersonics, Re-entry plasmas, Plasma-Surface Interactions, Non-equilibrium flows, Molecular Dynamics, Direct Simulation Monte Carlo (DSMC)

Associated Members

Adrián Domínguez Vázquez

Position: Associate Professor at Universidad de Málaga

Victor Tribaldos

Position: Professor at Universidad Universidad Carlos III de Madrid

José Miguel Reynolds Barredo

Position: Associate Professor at Universidad Carlos III de Madrid

Luis Raúl Sánchez Fernández

Position: Professor at Universidad Carlos III de Madrid

Postdoctoral Researchers

Marco Riccardo Inchingolo (Postdoctoral Researcher)

Research lines: Plasma diagnostics and electrodeless thrusters development

Jesús Perales Díaz (Postdoctoral Researcher)

Research lines: Ion Optics, Hall Effect Thruster, Full PIC and hybrid PIC/fluid modelling

Davide Poli (Postdoctoral Researcher)

Research lines: Advanced 2D Fluid Modelling of Hall effect Thruster discharges

Students

Tatiana Perrotin (PhD student)

Research lines: Design and test of a low power Hall thruster, plasma diagnostics and hollow cathodes

Célian Boyé (PhD student)

Research lines: Electrodeless Plasma Thruster design and testing.

Diego García Lahuerta (PhD student)

Research lines: Development of Multi-fluid models and codes.

Victor Gómez García (PhD student)

Research lines: Helicon Plasma Thruster.

Borja Bayón Buján (PhD student)

Research lines: Data driven analysis, machine learning applied to plasma space propulsion.

Matteo Guaita (PhD student)

Research lines: Hybrid PIC/fluid modelling of electron thermodynamics in plasma plumes

Matteo Ripoli (PhD student)

Research lines: Plasma waves and instabilities in magnetic nozzles

Andrés Rabuñal Gayo (PhD student)

Research lines: Air breathing electric propulsion

Simone Dalle Fabbriche (PhD student)

Research lines: Ion optics and plasma discharge in a radiofrequency ion thruster

Guillermo Cuerva Lazaro (PhD student)

Research lines: Hall effect thrusters, full PIC simulations, plasma instabilities and anomalous electron transport in Hall effect thrusters

Alumni

Filippo Cichocki

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

Daniel Pérez Grande

PhD Thesis: Fluid modeling and simulation of the electron population in Hall Effect Thrusters with complex magnetic topologies

Sara Correyero

PhD Thesis: Physics of plasma plumes accelerated by magnetic nozzles: an experimental and theoretical research

Álvaro Sánchez Villar

PhD Thesis: Modeling the plasma discharge in an electron cyclotron resonance thruster

Mick Wijnen

PhD Thesis: Diagnostic Methods for the Characterizatión of a Helicon Plasma Thruster

Enrique Bello Benítez

PhD Thesis: Analysis of turbulent transport in Hall-effect plasma thrusters

Pedro Jiménez Jiménez

PhD Thesis: Analysis of the wave-plasma ineraction in electrodeless plasma thrusters

Davide Maddaloni

PhD Thesis: Investigation of oscillations in space plasma thrusters via data-driven analysis techniques

Jesús Perales Díaz

PhD Thesis: Interacción con pared y apantallamiento magnético en Hall Effect Thrusters

Scherezade Barquero Balsera

PhD Thesis: Diagnostics for time-varying exhaust reconstruction applied to a low-power Pulsed Plasma Thruster: Thruster design, development, and characterization

Francisco de Borja de Saavedra Garcia del Río

PhD Thesis: Simulation and direct characterisation of electrostatic emission in externally wetted Ionic Liquid Ion Sources and its applications in space propulsion. Directores: Pablo Fajardo, Daniel Pérez Grande.

David Villegas Prados

PhD Thesis: Metodos avanzados de caracterización experimental de propulsores espaciales y su aplicación a la investigación sobre la emision electroestatica en propulsores basados en fuentes de liquidos ionicos

Contact

: 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
: ep2@uc3m.es

EP2ResearchGroup

St3llar

Peer-reviewed publications

Selected conference papers

PhD theses

EPT Workshop 2025

EP2
Research
Group