2022 EPS Hannes Alfvén Prize

Long citation

Professor Garbet’s principal accomplishments fall into six categories.
In the theory of turbulence spreading, he pointed out the possibility of bursty entrainment events, which de-localize turbulence relative to its point of excitation. This was a key initiator of the study of mesoscopic transport physics.
He has a leading role in the development of flux-driven simulations, both gyrokinetic and gyro-fluid. In particular, he inspired the building and exploitation of the GYSELA code, whose emphasis on flux-driven dynamics is unique among large gyrokinetic code efforts. The resulting significant review papers complement other notable reviews of gyrokinetics by their emphasis on physics interpretation.
He has made important contributions to internal transport barrier (ITB) physics to achieve improved confinement, where he led a Task Force of the JET programme in the early 2000s. He helped elucidate the role of resonant surfaces and magnetic shear in ITB formation. His scientific leadership was an important contribution to ITB confinement scenario development, a topic which is central to ITER.
A highlight of his excellent work clarifying and understanding the physics of ‘inward pinch’ processes relates to the up-gradient Turbulent Equipartition Pinch (TEP). The TEP, which is not thermodynamic, and is ultimately related to magnetic inhomogeneities, is the most robust and universal such process. He made important contributions to understanding the physics, by clarifying the relation between the TEP mechanism and the constraint of entropy production.
He has made important contributions to understanding plasma rotation and the transport of high-Z impurities, which radiate energy and trigger instabilities which are a major concern for the operation of magnetically confined plasmas. He unravelled synergistic interplays between collisional and turbulent transport, and highlighted mechanisms whereby experimentally observed spatial impurity distributions may be understood.
During the 1990s, he made important early contributions to understanding scrape-off layer (SOL) stability. He showed the possibility of interchange instability in the SOL, due to  its magnetic structure, which links in turn to the key ITER physics issue of SOL width.

2021 EPS Hannes Alfvén Prize

Long citation

Professor Sergei Igorevich Krasheninnikov has made vital contributions to an exceptionally broad range of aspects of a complex and multifaceted subfield of MCF plasma research: the physics of the scrape-off layer and divertor region. The processes that arise in this region at the very edge of the plasma link the hot core plasma to the solid material of the first wall. As design work in preparation for ITER has proven, these play a crucial role in the development of future magnetic fusion power plants. Studies of the scrape-off layer and divertor plasma physics are exceptionally complex, because of the many different interconnecting nonlinear processes that operate. These include classical and anomalous multicomponent plasma transport, atomic physics processes, plasma interactions with the first wall materials, and transport of plasma species in the lattice of these materials. Professor Krasheninnikov is widely acknowledged as a leading expert in this area of fusion research. His seminal ideas have helped build the foundations, and shaped the present understanding, of diverse aspects. These include the physics of “blobs”, divertor plasma detachment, the role of atomic physics processes, and the role of dust. His results on both atomic physics and dust are used well beyond magnetic fusion research. As a direct confirmation of the impact of Professor Krasheninnikov on the field, one may mention that the words “blobs” and “MAR”, which were coined by him to describe, respectively, coherent filamentary structures advected through the scrape-off layer and Molecular Assisted Recombination in divertor plasmas, are used in hundreds of magnetic fusion related papers worldwide.

2022 EPS Plasma Physics Innovation Prize

Long citation

Ane Aanesland and Dmytro Rafalskyi pioneered the use of iodine as a propellant for innovative satellite electric propulsion systems. Based on research work they originally performed at the Laboratoire de Physique des Plasmas at Ecole Polytechnique in France, they founded the company ThrustMe in 2017 to commercialize a new iodine propulsion technology. The system developed makes use of solid iodine propellant, which is then sublimated to form iodine gas. A plasma is then created using a radio-frequency inductive antenna, and positive iodine ions are extracted and accelerated with a set of high-voltage grids to produce thrust. After several years of development, the world’s first iodine electric propulsion system was launched into space on 6th November 2020 and subsequently successfully demonstrated in orbit. The results have recently been published in the leading scientific journal, Nature: less than a week after publication, the paper was already ranked within the top 5% of all articles ever tracked in terms of online media impact, and resulted in several hundred news articles and media interviews.
This new plasma-based technology is a major achievement for the space industry, and the impact of this work cannot be overstated: The electric propulsion system developed makes use of solid iodine propellant, which is sublimated to form iodine gas. A plasma is then created using a radio-frequency inductive antenna, and positive iodine ions are extracted and accelerated with a set of high-voltage grids to produce thrust. The use of iodine creates several complex challenges, which have required innovative solutions and fundamental physics investigations. Javier Martínez Martínez, as a senior engineer at ThrustMe, played a critical role by solving problems associated with corrosion, storage in space, and flow control. Within the space industry, high-performance electric propulsion systems have traditionally used xenon as the propellant. However, in contrast to iodine, xenon is very expensive, about €2500/kg; commercial production is limited; and it must be stored under very high pressure, typically one or two hundred times atmospheric pressure.
It is estimated that more than 24 000 satellites will be launched into space over the next ten years, and most will require propulsion systems. Space industry demand for xenon alone is anticipated to soon outpace supply, and it is critical that a viable replacement propellant be found. Iodine was identified over twenty years ago as a possible alternative to xenon but until now, despite being investigated by companies, space agencies, and universities around the world, no iodine propulsion system has ever been tested in space. Iodine is acknowledged as a transformative propellant. It is about a hundred times cheaper than xenon; it can be stored unpressurized as a solid, with a storage density almost three times higher than xenon; and is abundant, with global production around five hundred times higher than xenon. With growing space industry demand, and the rise of satellite mega-constellations, iodine will play a vital role in ensuring a sustainable space industry. In addition, because it can be stored as a solid, iodine enables substantial subsystem simplification and miniaturization. This allows a complete propulsion system to be provided to even very small satellites, and gives them a new capability for collision avoidance and for deorbiting to prevent space debris build-up. The high performance offered by an iodine plasma propulsion system will also enable advanced orbital manoeuvring for larger satellites, which will prove vital in the coming decades as humanity returns to the Moon and expands further into space.
It is impressive to see how Ane and Dmytro have taken their fundamental plasma research and, with the help of Javier, turned this into a product that is now available on the market and which has already gained significant commercial traction since its first demonstration in space.

EPS BPIF Board elections

The Election Committee registered 10 valid applications for the 3 open positions within the BPIF Board. At the end of the voting process, 92 bulletins were received. Among them, the Election Committee validated 85 bulletins, 7 bulletins being invalidated due to double inconsistent votes.

The results of the validated votes are given in the graph below.

The largest number of votes went to L. Gremillet, M. Kaluza and S. Depierreux. However, the Board members elected in one given round cannot be from the same country. Consequently, the Election Committee announces the final results of the elections.

Laurent Gremillet (CEA/DIF, France), Malte Kaluza (IOQ, FSU Jena, Germany) and Fabrizio Consoli (ENEA Frascati, Italy) are elected.

EPL Prizes for best research image/video and communication skills in plasma physics

2019 (all images and videos can be seen on the conference website here)

  • Images
    • M. Griener, IPP Garching (Germany) “Polychromator system for Helium Line Ratio Spectroscopy at ASDEX Upgrade”,
    • S. Smith, York University (UK) “MAST-U Super-X ELM simulation imaged by a simulated fast camera diagnostic”,
  • Videos
    • G. Blacard, CEA/Saclay (France) and LBNL (USA) “Orbital angular momentum transfer in two Laguerre Gaussian Beams”,
    • H. de Oliveira, EPFL (Switzerland) “Surviving in the Tokamak Heat”.

Citations for the 2020 EPS-PPD Research Awards

Archie Bott (University of Oxford): Magnetic-field amplification in turbulent laser-plasmas

This work combines theoretical simulations and experimental contributions in laser-generated-jet collision, in order to simulate in a laboratory what happens in various astrophysical contexts. In only the first year of his PhD, Archie Bott produced and published a complete theory of magnetic-field reconstruction from protons radiographic images and a full set of numerical codes needed to apply it. This “preparatory” work was used to significantly enrich this diagnostic tool that provided new information from experiments that he led on the most high-energy lasers in the word. These original studies and impressive work focused on time-resolved turbulent dynamo process. At the end of his PhD, Archie Bott returned to more theoretical and fundamental work, giving rise to another innovative publication of great depth in physics, which is essentially a comprehensive treatise on plasma instabilities at high beta.

Bart Ripperda (KU Leuven University): On magnetic reconnection and particle acceleration in relativistic plasmas

This is a theoretical and simulation work that concerns the astrophysics, and more precisely the environment of black holes and neutron stars. In his PhD work, Bart Ripperda combines very strong knowledge and understanding of plasma physics and general relativity, which allows him to tackle problems that are well beyond the scope of traditional plasma physics and astrophysics. He built a variety of word-class numerical tools for plasma physics in strong gravitational fields, including numerical schemes for general relativistic resistive magneto-hydrodynamics, and a set of algorithms for pushing charged particles in electromagnetic fields around black holes. This remarkable work on particle dynamics in full general relativity is of highest quality, and has already received broad recognition in the international plasma astrophysics community. It directly benefits the Event Horizon Telescope collaboration for which he has been actively working for a year.

Kevin Verhaegh (University of York): Spectroscopic investigations of detachment on TCV: Investigating the role of atomic physics on the ion current rollover and the dynamics of detachment in TCV

This thesis presents new results on the physics of detachment in a tokamak divertor, a complex topic because it involves not only plasma physics but also atomic phenomena. This is extensively discussed in Kevin Verhaegh’s thesis, showing clearly that he understands very well this physics. Kevin Verhaegh developed excellent divertor measurements and a novel method to analyse the data taking into account both the recombination and excitation contributions to the Balmer lines. He shows convincingly that the ion flux is not only due to recombination, as assumed during the last two decades, but that, in addition, the ionisation of the neutrals is an important contribution. Furthermore, he demonstrates that the latter is limited by a loss of power into the divertor recycling region when density increases, contributing significantly to the saturation. He validated these important results with modelling using the edge and divertor code SOLPS-ITER, showing that the modelling results match the experimental observations much better than in the past. This new view contributes significantly to fusion research as divertor detachment will be required in future devices to reduce the power load. With this new knowledge modelling and extrapolation of divertor detachment are more reliable.

Rogério Jorge (EPFL & University of Lisbon): A moment-based model for plasma dynamics of arbitrary collisionality

This thesis tackles a long-standing problem, namely, how to develop a set of equations that can uniformly describe plasma behaviour in situations where the collisionality ranges from essentially collision-less to highly collisional, a situation that pertains in the edge region of a tokamak in particular. This region is crucial to a tokamak’s performance and the viability of fusion as an energy source, controlling overall confinement and exhaust; an ability to model the region is essential for the development of fusion power. This thesis develops a set of fluid-like moment equations suitable for this purpose. The derivation is based on a Sonine-Laguerre expansion of the drift-kinetic plasma equations and treats the full non-linear Coulomb collision operator, an analytic tour-de- force. The model is appropriate for describing the scrape-off-region, which contains open magnetic field lines and lies between the confined plasma region and the containment vessel; furthermore, it can describe the large fluctuations that are present there.  A similar procedure is also applied in the thesis to the full-F gyro-kinetic model, which is suitable for modelling the adjacent confinement region of a tokamak. In addition, efficient numerical algorithms for computing solutions to these equations are formulated. Finally, the methodology is applied in practice to study the impact of collisions on plasma oscillations and drift waves, using different common simplified collision models; the results show surprising sensitivities.  The model is now ready for application to the tokamak edge problem. This work, performed independently and with considerable initiative, constitutes a seminal contribution to magnetic confinement fusion, and plasma theory in general, demonstrating novelty and originality and exhibits both analytic and numerical skills.