Periodic Reporting for period 3 - ZARATHUSTRA (Revolutionizing advanced electrodeless plasma thrusters for space transportation)
Reporting period: 2024-01-01 to 2025-06-30
Electrodeless Plasma Thrusters (EPTs) are a new type of space propulsion that promises to overcome the limitations of traditional electric propulsion technologies and to offer unparalleled advantages in terms of power scaling, throttling range, lifetime, propellant types, and simplicity. Nevertheless, EPT development is currently stuck due to the incomplete understanding of their physics, in particular electromagnetic (EM) plasma heating and anomalous transport. Additionally, the cylindrical geometry of existing EPT designs has inherent issues, with high plasma losses and erosion at the rear wall of the ionization chamber and a wide divergence of the generated plasma jet. ZARATHUSTRA aims to unravel the physical underpinnings of EPTs and revolutionize their design by accomplishing three objectives: (1) establish the first self-consistent model of EM plasma heating in these devices; (2) elucidate the role of plasma turbulence, wall interactions, and applied EM fields on anomalous transport and devise control solutions to minimize plasma losses; and (3) assess the feasibility and advantages of a disruptive non-cylindrical EPT concept. This will be made possible thanks to a unique multidisciplinary methodology based on: a ground-breaking two-level numerical simulation strategy with a novel electromagnetic-kinetic algorithm; state-of-the-art experimental measurements; advanced data analysis techniques; and thruster bread-board prototype development. As a result, the first complete theory of EM heating and anomalous transport in EPTs will be formulated, and the path will be paved for the development of a new generation of plasma thrusters with unsurpassed characteristics and performances. While the high ambition of the project represents high risk, this is more than compensated by the potential high gain: uncovering the physical mechanisms of EPTs, unblocking their progress, and claiming for Europe a privileged leadership position in this strategic field.
The work in ZARATHUSTRA so far has been articulated about 8 major axes:
1) Characterization of electron kinetics in the 2D plasma expansion in a MN. Effort has concluded with 2 publications, including an international review paper.
2) Development of a multifluid plasma code. The code has been applied to the simulation of the plasma expansion in a magnetic arch, a new magnetic topology for plasma acceleration that occurs when combining two cylindrical electrodeless plasma thrusters (EPTs) with opposing polarities, and which is a characteristic aspect of the new magnetic arch thruster (MARCH). Effort has led to 1 publication so far; another on magnetic nozzles is being prepared.
3) Development of a full wave code. It has been used to simulate the radiation and power absorption in a helicon plasma thruster (HPT). Effort has led to 1 publication so far.
4) Initiation of the development of an advanced, state-of-the-art, time-implicit energy-conserving Particle-in-cell (PIC) code to simulate plasma kinetics, in collaboration with LANL, USA. The incipient code has already been verified against existing 1D simulations of a MN, and a paper has been published.
5) Development of fast plasma diagnostics and data-driven diagnostic techniques. These have been applied to the MN of a HPT in the laboratory, to reveal the azimuthal oscillations present in the plasma. A journal publication is being prepared.
6) Derivation of dispersion relations relevant to the oscillations in the plasma of a MN, including parallel propagation and collisions, to set up an initial theoretical framework to understand the observations of the previous point. A journal publication is being prepared.
7) Development of an experimental setup to validate the magnetic arch plasma acceleration concept. Using two cylindrical plasma sources in parallel, with opposing polarities, the formation of a plasma jet in the resulting magnetic arch has been validated. A publication is being prepared.
8) Application of data-driven analysis techniques (in particular, symbolic regression with modified SINDy algorithms) to obtain simple models of the oscillations in a Hall effect plasma thruster. A publication is being prepared.
Various PhD thesis have been completed or are ongoing in the framework of the project. Additionally, BSc and a MSc theses have been concluded as part of ZARATHUSTRA. A set of publicly-available trainings have been produced and recorded on video, with ancillary slides/lecture notes, to train the current PhD/MSc/BSc students and those to come (https://ep2lab.github.io/trainings(opens in new window)).
Project dissemination and outreach has included several presentations in international congresses, the organization of one international Workshop in Madrid, and several outreach actions in Madrid’s week of science, European researcher’s night, interviews in National and regional media, local seminars, and posts in the project twitter account (https://twitter.com/ERC_Zarathustra(opens in new window)). All the results of the project are linked from the project website (https://erc-zarathustra.uc3m.es/(opens in new window)).
1) Characterization of electron kinetics in the 2D plasma expansion in a MN. Effort has concluded with 2 publications, including an international review paper.
2) Development of a multifluid plasma code. The code has been applied to the simulation of the plasma expansion in a magnetic arch, a new magnetic topology for plasma acceleration that occurs when combining two cylindrical electrodeless plasma thrusters (EPTs) with opposing polarities, and which is a characteristic aspect of the new magnetic arch thruster (MARCH). Effort has led to 1 publication so far; another on magnetic nozzles is being prepared.
3) Development of a full wave code. It has been used to simulate the radiation and power absorption in a helicon plasma thruster (HPT). Effort has led to 1 publication so far.
4) Initiation of the development of an advanced, state-of-the-art, time-implicit energy-conserving Particle-in-cell (PIC) code to simulate plasma kinetics, in collaboration with LANL, USA. The incipient code has already been verified against existing 1D simulations of a MN, and a paper has been published.
5) Development of fast plasma diagnostics and data-driven diagnostic techniques. These have been applied to the MN of a HPT in the laboratory, to reveal the azimuthal oscillations present in the plasma. A journal publication is being prepared.
6) Derivation of dispersion relations relevant to the oscillations in the plasma of a MN, including parallel propagation and collisions, to set up an initial theoretical framework to understand the observations of the previous point. A journal publication is being prepared.
7) Development of an experimental setup to validate the magnetic arch plasma acceleration concept. Using two cylindrical plasma sources in parallel, with opposing polarities, the formation of a plasma jet in the resulting magnetic arch has been validated. A publication is being prepared.
8) Application of data-driven analysis techniques (in particular, symbolic regression with modified SINDy algorithms) to obtain simple models of the oscillations in a Hall effect plasma thruster. A publication is being prepared.
Various PhD thesis have been completed or are ongoing in the framework of the project. Additionally, BSc and a MSc theses have been concluded as part of ZARATHUSTRA. A set of publicly-available trainings have been produced and recorded on video, with ancillary slides/lecture notes, to train the current PhD/MSc/BSc students and those to come (https://ep2lab.github.io/trainings(opens in new window)).
Project dissemination and outreach has included several presentations in international congresses, the organization of one international Workshop in Madrid, and several outreach actions in Madrid’s week of science, European researcher’s night, interviews in National and regional media, local seminars, and posts in the project twitter account (https://twitter.com/ERC_Zarathustra(opens in new window)). All the results of the project are linked from the project website (https://erc-zarathustra.uc3m.es/(opens in new window)).
The Project aims to bring the understanding of Electrodeless Plasma Thrusters beyond the current state of the art, and revolutionize their design.
Expected results at the end of the project include:
- Multi-fluid plasma simulation code
- Full-wave, frequency-domain, finite-element (FE) code
- Versatile EM-kinetic code and innovative propagation algorithm
- Fluid, EM, and kinetic simulations of EPTs and the magnetic arch thruster
- Cylindrical and magnetic arch plasma sources for experimental studies
- Versatile set of plasma and thruster diagnostics
- Reusable experimental datasets
- MA plasma acceleration and detachment theory
- EM heating and anomalous transport theories
- Magnetic Arch for plasma acceleration: feasibility assessment and characterization
Expected results at the end of the project include:
- Multi-fluid plasma simulation code
- Full-wave, frequency-domain, finite-element (FE) code
- Versatile EM-kinetic code and innovative propagation algorithm
- Fluid, EM, and kinetic simulations of EPTs and the magnetic arch thruster
- Cylindrical and magnetic arch plasma sources for experimental studies
- Versatile set of plasma and thruster diagnostics
- Reusable experimental datasets
- MA plasma acceleration and detachment theory
- EM heating and anomalous transport theories
- Magnetic Arch for plasma acceleration: feasibility assessment and characterization