Qui suis-je ? L'interview (n°2)... des membres de la Fédération PLAS@PAR

Dans la dernière newsletter de PLAS@PAR, un membre de la fédération à répondu aux 6 questions ci-dessous sans donner son identité, l'aviez-vous découvert ? Nous levons le mystère aujourd'hui...

ÉNIGME

1. Je suis... expérimentateur.
2. J’étudie... les plasmas de laboratoire.
3. Si j’étais un dispositif pour produire des plasmas, je voudrais être... une machine de Wimshurst.
4. Si les plasmas étaient une œuvre, ce serait... une planche d’une scène de bagarre dans le village de la BD d’Astérix.
5. Si les plasmas étaient une couleur, ce serait... la somme de toutes, le blanc !
6. Si les plasmas étaient un sport, ce serait... une partie de billard.

---------------

INTERVIEW

Bonjour Jérôme Pulpytel, docteur en génie des procédés, maitre de conférences, Laboratoire LISE, Equipe MATTERFEEL), vous êtes désormais démasqué ! Pouvez-vous nous en dire en peu plus sur votre parcours ? 

Je suis chimiste de formation. Après un DEA en génie des procédés, j’ai donc continué avec une thèse dans le domaine des plasmas froids afin d’élaborer des matériaux en couches minces à l’aide de décharges à basse pression.

Pouvez-vous en dire un peu plus sur vos recherches actuelles en physique des plasmas ?

Désolé je n’étudie pas la physique des plasmas, mais leurs nombreuses applications dans le domaine des matériaux et des traitements de surfaces. Les chimistes sont des « artisans de la matière » ; ils élaborent de nouvelles molécules ou matériaux en mettant en œuvre différents procédés, et les propriétés particulières des plasmas hors équilibres permettent d’obtenir des résultats qui ne seraient pas possible par d’autres moyens, comme par exemple par simple chauffage des ingrédients dans un four. Ainsi, nous nous servons des plasmas pour protéger le métal contre la corrosion par dépôt de couches minces, pour encapsuler des agents de chimiothérapie à l’aide de polymères-plasma biodégradables ou encore pour élaborer des matériaux servant à décontaminer l’eau ; et nous construisons souvent nos réacteurs plasmas nous-même.

Pouvez-vous partager avec nous les références de vos dernières publications ?

- Anagri et al., “Nanocomposite coatings based on graphene and siloxane polymers deposited by atmospheric pressure plasma. Application to corrosion protection of steel“, Surf. Coat. Technol., 377, 124398. (2019)

- Baitukha et al., “Optimization of a low pressure plasma process for fabrication of a Drug Delivery System (DDS) for cancer treatment“, Mater. Sci. Eng. :C, 105, 110089. (2019)

- T. Peng et al., “One‐step deposition of nano‐Ag‐TiO2 coatings by atmospheric pressure plasma jet for water treatment: Application to trace pharmaceutical removal using solar photocatalysis“, Plasma Process. Polym, 16(6), 1800213 (2019)

Pouvez-vous nous en dire un peu plus sur les actions d’enseignement que vous menez ?

Je donne des cours dans le domaine du Génie des Procédés. Le génie des procédés, consiste à appliquer les principes des cinétiques réactionnelles, des transferts de matières et de chaleur au sein de réacteurs chimiques. Notre objectif est de comprendre et de maitriser tous les phénomènes qui s’y déroulent pour pouvoir transposer la production chimique à grande échelle ; ainsi il ne s’agit pas de chimie fondamentale mais d’une approche plus large et pluridisciplinaire au carrefour de la chimie, des mathématiques et de la physique. Dans ce cadre, j’introduis également un peu aux étudiants les spécificités des réacteurs plasmas et ce que l’on peut obtenir avec en laboratoire et en milieu industriel. Enfin, je m’appui sur le FabLab SU pour réaliser des projets Arduino® avec mes étudiants (ex. réaliser une machine qui dose le pH automatiquement).

Sur quel(s) site(s) travaillez-vous ?

Sur le campus Pierre et Marie Curie (Sorbonne Université), au niveau des tours 14-24

Quel est votre rôle au sein de la communauté PLAS@PAR ?

Je viens juste d’être nommé au Conseil de fédération, alors reposez-moi cette question un peu plus tard :-)

Menez-vous des actions auprès du grand public de manière ponctuelle ou régulière, si oui, pouvez-vous expliquer ?

Absolument et depuis longtemps. D’abord à la fête de la Science où je m’amuse beaucoup avec mes plasmas, en proposant aux gens de tenir un tube un néon devant une boule plasma, en faisant une chaine humaine aussi et la Wimshurst a toujours beaucoup de succès mais gare où on met les doigts ! Également j’ai fait une conférence expérimentale filmée à l’ESPCI (2013) et un café des Sciences dans ma communauté de commune (sud 77, 2019).

Si PLAS@PAR doit relever un défi pour les 5 prochaines années, quel est-il selon vous ?

Les plasmas devraient réussir à intéresser et à aller d’avantage à la rencontre des chimistes, biologistes et des médecins. À ma modeste échelle, je donne 2 heures de cours à des étudiants en biologie où je leur montre les avancées spectaculaires des plasmas froids dans le domaine de la santé (traitement de cancer, cicatrisation, décontamination/stérilisation des surfaces etc…). Il y a tellement de collègues et d’étudiants non physiciens qui pourraient être intéressés !

Un dernier mot ?

Faites attention à vous et restez en bonne santé.

Merci beaucoup Jérôme Pulpytel ! À qui le tour ?

Modélisation de plasmas d'iode pour la propulsion spatiale (PhD)

Proposition de Projet de Recherche Doctoral (PRD)

Appel à projet IPhyInf - Initiative Physique des infinis 2020

Intitulé du Projet de Recherche Doctoral : Modélisation de plasmas d'iode pour la propulsion spatiale

-------

Directeur de Thèse porteur du projet :

Sisourat Nicolas, Maître de conférence des universités (Nicolas.Sisourat@sorbonne-universite.fr)

Site : Sorbone Université, 4 Place Jussieu, Tour 43-44, 1er étage

Unité de Recherche : Laboratoire de Chimie Physique Matière et Rayonnement - UMR 7614

Ecole Doctorale de rattachement de l’équipe & d’inscription du doctorant : ED388- ChimiePhysique&ChimieAnalytiq ue ParisCentre

Co-encadrant :

Bourdon Anne, Directeur de Recherche (anne.bourdon@lpp.polytechnique.fr)

Unité de Recherche : Laboratoire de Physique des Plasmas - UMR 7648

Ecole Doctorale de rattachement : École doctorale de l’Institut Polytechnique de Paris (ED IP Paris)

>>> Pour candidater, merci de contacter et/ou d'envoyer vos dossiers aux encadrants dont les emails sont ci-dessus.

Description du projet de recherche doctoral

Introduction, state of the art, and objectives

Electric thrusters for space vehicles have been developed across the world since the 1960s, and have been since then deployed on hundreds of satellites and space exploration probes [1-5]. However, thanks to the recent increase in available power on spacecraft, the full potential of electric propulsion is now achievable. This is demonstrated by the emergence of all-electric communication satellites and projects requiring the deployment of large constellations of small electric-powered satellites [5].

jects requiring the deployment of large constellations of small electric-powered satellites [5]. Many electric thruster design concepts have been investigated (including arcjets, resistojets, Halleffect thrusters, gridded ion thrusters and pulsed plasma thrusters, see [5] for a recent review). However, the basic physical principles are unchanged: a propellant is ionized to form a plasma, and the ions created are accelerated out of the device by electromagnetic fields, providing thrust through the conservation of momentum. An efficient propellant should therefore be easy to ionize and have a high atomic/molecular mass, in order to yield a high flux of heavy ions for a given electric power, thus exerting a large force on the satellite. Xenon is currently the propellant of choice, due to its high atomic mass and low ionization potential. However, xenon is rare, expensive, and must be stored either in (heavy) high-pressure tanks or at cryogenic temperatures, significantly impacting the useable volume in satellites. The iodine molecule is an interesting replacement candidate, since it also has a high atomic mass and a low ionization potential. In contrast, it is cheap, and exists in the solid state at standard pressure and temperature, but with a conveniently high vapour pressure. These properties result in a storage density of iodine that is three times higher than that of xenon under equivalent conditions.

In an iodine plasma thruster, electrical energy supplied to electrons serves to ionize the iodine molecules to form a plasma. However, due to the molecular nature of this gas, electron energy is inevitably dissipated in other processes, including electronic, vibrational and rotational excitation and dissociation, producing various atomic and molecular iodine species, both neutral and ionized. Only ions can be accelerated electrically to produce thrust. However, these charged species can return to neutral ones through various reactions (recombination, neutralisation) causing substantial power loss. There is currently little reliable data available on most of these processes, preventing a valid description and modelling of iodine thrusters. The aim of the project is to create the first complete model of iodine plasmas. To achieve this goal, we will identify the major reactions impacting the efficiency of an iodine thruster and quantify them. Furthermore, these data will be implemented in an accurate plasma model. Ultimately, our simulations will be able to predict the composition of iodine plasmas in real conditions, allowing the determination of the optimal parameters for high thruster efficiency.

Research methodology and PhD project

The aim of the PhD project is to compute the cross sections of the elementary collision processes occurring in the volume of iodine plasmas. The dominant species present in an iodine plasma are I, I₂, I⁺ , I₂⁺ , I^- and I₂. We will use the Landau-Zener Surface Hopping (LZSH) approach [6] to obtain the cross sections of the reactions taking place between these species. LZSH has the significant advantage that only adiabatic potential energy surfaces (PES) are needed, in contrast to most standard methods for which nonadiabatic couplings are necessary and tedious diabatization procedures must be applied. The PES will be computed with the relativistic equation-of-motion coupled-cluster method from the DIRAC code [7,8]. This approach directly includes spin-orbit coupling, which is an important effect in iodine, already at the Hartree-Fock level [9]. These cross sections will then be used to develop a first global plasma model.

Nicolas Sisourat will advise the PhD candidate on the LZSH study. He has over 10 years of experience in the simulation of inelastic electronic processes and has developed several state-of-theart codes for such simulations. Anne Bourdon is an expert in plasma physics, electric propulsion and their modelling. She will be the advisor of the PhD candidate on the implemention of the global model for electric propulsion applications. The complementary of the two advisors is a strong asset of the PhD project.

Originality and innovative aspects of the proposal

Although iodine was proposed as an alternative propellant nearly 20 years ago [10,11], there have been only a few experimental investigations of their performance (see [12,13] and references therein). Furthermore, to our knowledge, there has been only two modelling studies of the iodine plasma composition [14,15] owing, precisely, to the lack of available data.

The PhD project will fill this gap. To achieve its scientific goals a trans-disciplinary approach is essential. We will tackle the challenging task of considering all aspects of an iodine plasma. Combining state-of-the-art relativistic electronic structure calculations, simulations of atomic and molecular collisions and plasma modelling will provide a description of iodine plasma thrusters with unprecedented accuracy, which will have significant impact in the rapidily growing field of electric propulsion.

Relevance of the project for the Initiative Physique des infinis

As detailed above, the aim of the PhD project is to provide a detailed and accurate description of iodine plasma thrusters. Such a fundamental and ambitious goal requires improving our understanding of the atomic and molecular processes taking place in the plasma as well as the physics of the plasma itself. Furthermore, the need for small electric-powered satellites is on a constant rise owing to their commercial and military applications. The PhD project will therefore have a significant societal impact. These objectives are at the core of the Initiative Physique des infinis.

Profile of the PhD Applicant

The PhD applicant should have a master degree in Chemistry or Physics. She/He should have good competence in programming and numerical methods. Knowledge in plasma physics and/or theoretical chemistry approaches will be an asset.

References

• [1] E. Y. Choueiri Propulsion Power 20, 193 (2004).
• [2] D.M. Goebel and I. Katz, Fundamentals of Electric Propulsion (Hoboken, NJ: Wiley) (2008).
• [3] E. Ahedo, Plasma Phys. Control. Fusion 53, 124037 (2011).
• [4] S. Samukawa et al. J. Phys. D: Appl. Phys. 45, 253001 (2012).
• [5] S. Mazouffre, Plasma Sources Sci. Technol. 25, 033002 (2016).
• [6] A.K. Belyaev et al. J. Chem. Phys. 140, 224108 (2014).
• [7] Dirac, a relativistic ab initio electronic structure program, http://www.diracprogram.org.
• [8] A. Shee et al. arXiv: 1808.08205 (2018).
• [9] V. Vallet et al. J. Chem. Phys. 113, 1391 (2000).
• [10] R. Dressler, Y.-H. Chiu, and D. Levandier, 38th Aerospace Sciences Meeting and Exhibit (2000).
• [11] O. Tverdokhlebov and A. Semenkin, 37th Joint Propulsion Conference and Exhibit (2001).
• [12] J. Szabo et al. 33rd International Electric Propulsion Conference (2013).
• [13] T.D. Smith et al. NASA Technical reports (2016).
• [14] P. Grondein et al. Phys. Plasmas 23, 033514 (2016).
• [15] R. Lucken, F. Marmuse, A. Bourdon, P. Chabert and A. Tavant, Proceedings of the IEPC conference (2019).

Publications of the advisors that are relevant for the present proposal

1. J. W. Gao, Y. Wu, J. G. Wang, A. Dubois and N. Sisourat; Double electron capture in H + + H − collisions, Phys. Rev. Lett. 122, 093402 (2019).
2. A. Puglisi, T. Miteva, E. T. Kennedy, J.-P. Mosnier, J.-M. Bizau, D. Cubaynes, N. Sisourat and S.
3. Carniato; X-ray photochemistry of carbon hydride molecular ions, Phys. Chem. Chem. Phys. 20, 4415 (2018). 3) V. Croes, A. Tavant, R. Lucken, R. Martorelli, T. Lafleur, A. Bourdon and P. Chabert; The effect of alternative propellants on the electron drift instability in Hall-effect thrusters: Insight from 2D particle-in-cell simulations, Physics of Plasmas 25, 063522 (2018).
4. P. Grondein, T. Lafleur, P. Chabert, and A. Aanesland; Global model of an iodine gridded plasma thruster, Physics of Plasmas 23, 033514 (2016).

Charged particle dynamics in solar wind coherent structures (PhD)

Proposition de Projet de Recherche Doctoral (PRD)

Appel à projet IPhyInf - Initiative Physique des infinis 2020

Intitulé du Projet de Recherche Doctoral : Charged particle dynamics in solar wind coherent structures

-------

Directeur de Thèse porteur du projet :

Maksimovic Milan, Directeur de recherche (milan.maksimovic@obspm.fr)

Site : 5, place Jansse, 92190 Meudon; bat.16, bureau 202

Unité de Recherche : LESIA - UMR 8109

Ecole Doctorale de rattachement de l’équipe & d’inscription du doctorant : ED127-AstronomieAstrophysiqueIdF

Co-encadrant :

Anatoly Petrukovich, Directeur de Recherche (a.petrukovich@cosmos.ru)

Unité de Recherche : Space Research Institute of Russian Academy of Sciences (IKI, Moscow)

Ecole Doctorale de rattachement : ED127-AstronomieAstrophysiqueIdF

>>> Pour candidater, merci de contacter et/ou d'envoyer vos dossiers aux encadrants dont les emails sont ci-dessus.

Description du projet de recherche doctoral

Context

The solar wind is a supersonic plasma stream frozen into an interplanetary magnetic field accelerated away from the Sun. Solar wind measurements at a wide range of distances from the Sun show that radial evolution of ion temperature significantly differs from the adiabatic expansion (Cranmer et al., 2009, Elliott et al., 2016). It means that there must be gradual heat input into the solar wind plasma that begins in the corona and extends far out into interplanetary space (Parker 1963; Leer et al. 1982; Tu & Marsch 1995; Goldstein et al. 1995; Marsch 1999; Hollweg & Isenberg 2002; Cranmer 2002; Matthaeus et al. 2003). Solution of the solar wind heating problem is extremely important both for understanding the structure of the heliosphere and for adequately describing the atmospheres of distant stars. The modern theories suggest that turbulence [Bruno & Carbone 2013] and emerged coherent structures [e.g., Greco et al. 2009, Alexandrova 2008, Lion et al. 2016] can significantly contribute to the solar wind heating, but there is no well accepted concept for a mechanism responsible for such heating.

Scientific objectives

The aim of this PHD project is to study coherent structures in the turbulent solar wind (e.g., current sheets, shocks, vortices) and their role in ions and electrons dynamics. To approach this problem, the candidate will combine multi-satellite data analysis at 1 AU with NASA/MMS and ESA/Cluster missions, theoretical models, and numerical simulations. The results will be then applied to understand new measurements of the NASA/Parker Solar Probe (PSP) and ESA/Solar Orbiter (SOLO) missions closer to the Sun.

First of all, we will determine the dominant coherent structures in the turbulent solar wind and the solar wind behind the Earth's bow-shock (the so-called magnetosheath). This work will be based on magnetic field measurements at different scales and in 4 points in space in order to separate time and space variations (crucial for the coherent structures identification). This analysis is possible with Cluster in the free solar wind and with MMS in the Earth's magnetosheath. Second, we will do an analysis of ion and electron distribution functions within the dominant coherent structures using high resolution particle measurements on MMS in the Earth's magnetosheath.

These two observational steps will be done at LESIA/Paris Observatory (Meudon) under the supervision of Milan Maksimovic and in collaboration with Olga Alexandrova. The observational results will be then the basis of the modeling and numerical simulations, which will be done in IKI (Moscow) with Anatoly Petrukovich, in collaboration with Anton Artemyev in UCLA (Los Angeles, USA). Main theoretical approaches include perturbation theory for resonant Hamiltonian systems and theory of adiabaticity destruction in Hamiltonian systems with separatrices. Using these approaches, efficiency of ion and electron scattering by coherent structures of different configurations will be investigated. Numerical simulations of ion and electron interaction with coherent solar wind structures will include massive test particle simulations and self-consistent hybrid simulations.

The final step will be comparison of 1 AU observations with the new measurements in previously unexplored regions made by the Solar Orbiter and Parker Solar Probe closer to the Sun. 

Justification of the scientific approach:

In order to understand the solar wind evolution and heating, we propose here to do the data analysis of Cluster and MMS at 1 AU, SOLO at 0.3-1AU and Parker Solar Probe at 0.05-0.3 AU. Note that the instrumentation is quite different on the four space missions.

Approaching the Sun, the conditions are such that important constraints have been made on the instruments and data telemetry for PSP and SOLO. The most sensitive instrument ever measuring turbulent fluctuations at kinetic scales (where one expects particle-turbulence interactions) is Cluster/STAFF (search coil magnetometer), which can resolve ion and electron scales at 1 AU. MMS has been designed for the Earth's magnetosphere studies (including solar wind between the bow-shock and the magnetopause, i.e., within the magnetosheath) and it provides the highest cadency for ion and electron distribution functions, but also less sensitive magnetic measurements at kinetic scales. PSP and SOLO have less sensitive search coil magnetometers than Cluster/STAFF, the particle instruments have lower cadency than MMS. Both missions are composed of a single spacecraft (which makes it impossible to separate time and space variations), by opposition with Cluster and MMS.

To resume, using multi-satellites Cluster and MMS, we will be able to separate between time and space variations and fully characterize coherent structures. High quality measurements of turbulent fluctuations and particle distributions at 1 AU will allow a detailed modeling. Then, using our knowledge at 1 AU, we will be able to interpret properly PSP and SOLO measurements closer to the Sun.

It is crucial to have a strong observational and theoretical background thanks to the study proposed here to interpret correctly the new observations of PSP and SOLO and advance our understanding of solar wind physics.

Adequation to "Initiative Physique des Infinis"

This project is in full adequation with the "Initiative Physique des Infinis" as far as it aims to better understand the behavior of (charged) particles in (turbulent space) plasmas.

The problem of turbulence is one of the open problems in modern physics. Here we address the electromagnetic turbulence in astrophysical collisionless plasmas, where the usually (collisional) dissipation is not efficient. This problem covers a very large rangе of scales, from ~ 1AU to very small (for astrophysics) ~ 1km. Precisely, from the propagation of magnetic structures over Sun-Earth distance (scales ~ 1 AU), to scales of turbulence/particles interaction (~1-1000 km).

The aim of the project is to understand physical processes which govern in the complex turbulent space plasmas and their impact on the solar wind expansion in the Heliosphere. Thanks to the proposed collaboration between LESIA and IKI, the candidate will use the diversity of approaches (theory, modeling, data analysis of different spacecrafts in the Heliosphere).

The student will participate in doctoral schools devoted to plasma physics (from laboratory to astrophysics, like the one organized every 2 years in 'Ecole de Physique des Houches', e.g., http://geoffroy-lesur.org/plasmas2017/) and to satellite data mining.

Role of each supervisor and the scientific skills provided:

Milan Maksimovic (DR/CNRS, LESIA): Supervision of spacecraft observations and data analysis. PI of SOLO/RPW instrument, CoI of FIELDS/PSP instrument (PI Stuart Bale, Berkeley), CoI of Cluster/STAFF. Expert of space instrumentation in general and of SOLO, PSP, Cluster in particular. Expert of solar wind modeling.

Anatoly Petrukovich (Director of Space Research Institute of Russian Academy of Sciences (IKI), Moscow, Russia; correspondent member of the Russian Academy of Sciences): Supervision of spacecraft observations and observation/theory comparison. Expert in magnetospheric plasma dynamics and in spacecraft instrumentation.

Olga Alexandrova (ASAD/CNAP, LESIA): Collaboration on the spacecraft observations, data analysis and modeling. Expert of space plasma turbulence and coherent structures. CoI of Cluster/STAFF, CoI of SOLO/RPW.

Anton Artemyev (Associate Researcher UCLA, IKI): Collaboration on the spacecraft observations, theoretical modelling and numerical simulations. Expert in plasma physics theory.

Student profile

Knowledge of plasma physics. Some knowledge of space physics and heliosphere are desirable, but not obligatory.

Publications / productions of the supervisors in connection with the project

LESIA TEAM

1. Maksimovic, Milan; Pierrard, Viviane; Lemaire, Joseph, On the Exospheric Approach for the Solar Wind Acceleration, Astrophysics and Space Science, v. 277, Issue 1/2, p. 181-187 (2001).
2. Maksimovic, M.; Zouganelis, I.; Chaufray, J. -Y et al., Radial evolution of the electron distribution functions in the fast solar wind between 0.3 and 1.5 AU, Journal of Geophysical Research: Space Physics, Volume 110, Issue A9, CiteID A09104, 09/2005
3. Maksimovic, M.; Bale, S. D.; Berčič, L. et al., Anticorrelation between the Bulk Speed and the Electron Temperature in the Pristine Solar Wind: First Results from the Parker Solar Probe and Comparison with Helios, The Astrophysical Journal Supplement Series, Volume 246, Issue 2, id.62, 02/2020
4. O. Alexandrova, A. Mangeney, M. Maksimovic, N. Cornilleau-Wehrlin, J. M. Bosqued, M. Andre, Alfven vortex filaments observed by Cluster in the magnetosheath downstream of perpendicular shock, J. Geophys. Res., Vol. 111, A12208, 2006
5. Alexandrova, O.; Chen, C. H. K.; Sorriso-Valvo, L.; Horbury, T. S.; Bale, S. D., Solar Wind Turbulence and the Role of Ion Instabilities, Space Science Reviews, Volume 178, Issue 2-4, pp. 101-139, 2013.
6. Lion, Sonny; Alexandrova, Olga; Zaslavsky, Arnaud, Coherent Events and Spectral Shape at Ion Kinetic Scales in the Fast Solar Wind Turbulence, The Astrophysical Journal, Volume 824, Issue 1, article id. 47, 13 pp. (2016)
7. Tieyan Wang, Olga Alexandrova, Denise Perrone et al., Magnetospheric Multiscale Observation of Kinetic Signatures in the Alfvén Vortex, The Astrophysical Journal Letters, Volume 871, Issue 2, article id. L22, 12 pp. (02/2019).
8. Jovanovic, Dusan; Alexandrova, Olga; Maksimovic, Milan; Belic, Milivoj, Fluid theory of coherent magnetic dipolar and quasi-monopolar structures in high-beta plasmas of the Solar wind and of the Earths magnetosheath, eprint arXiv:1705.02913, 2017arXiv170502913J, APJ, 2020, in press

IKI TEAM

1. Petrukovich A. A., A. V. Artemyev, R. Nakamura, E. V. Panov, and W. Baumjohann. Cluster observations of dBz/dx during growth phase magnetotail stretching intervals. 2013 J. Geophys. Res. 118, 5720–5730, doi:10.1002/jgra.50550, 2013
2. Artemyev A.V., A.A. Petrukovich, A.G. Frank, R. Nakamura, L.M. Zelenyi. Intense current sheets in the magnetotail: Peculiarities of electron physics. 2013. J. Geophys. Res. 118, 2789–2799, doi: 10.1002/jgra.50297
3. Zelenyi L M, Neishtadt A I, Artemyev A V, Vainchtein D L, Malova H V “Quasiadiabatic dynamics of charged particles in a space plasma” Phys. Usp. 56 347–394 (2013); DOI: 10.3367/UFNe.0183.201304b.0365
4. Artemyev A. V., Neishtadt A. I., Zelenyi L. M., Rapid geometrical chaotization in slow-fast Hamiltonian systems. Physical Review E, 89, 060902(R), 2014, doi: 10.1103/PhysRevE.89.06090
5. Artemyev, A.V., Neishtadt, A.I., Zimovets, I.V. et al. Chaotic Charged Particle Motion and Acceleration in Reconnected Current Sheet. Sol Phys 290, 787–810 (2015). https://doi.org/10.1007/s11207-014-0639-y
6. Petrukovich Anatoli, Anton Artemyev, Ivan Vasko, Rumi Nakamura, Lev Zelenyi. Current Sheets in the Earth Magnetotail: Plasma and Magnetic Field Structure with Cluster Project Observations. Space Sci Rev (2015) 188:311–337, DOI 10.1007/s11214- 014-0126-7
7. Artemyev Anton V., Vassilis Angelopoulos, Jasper S. Halekas, Alexander A. Vinogradov, Ivan Y. Vasko, and Lev M. Zelenyi, Dynamics of Intense Currents in the Solar Wind, The Astrophysical Journal, 859:95 (11pp), 2018
8. Petrukovich A A, Malova H V, Popov V Yu, Maiewski E V, Izmodenov V V, Katushkina O A, Vinogradov A A, Riazantseva M O, Rakhmanova L S, Podladchikova T V, Zastenker G N, Yermolaev Yu I, Lodkina I G, Chesalin L S "Modern view on solar wind from micro to macro scales" Phys. Usp., 2020, accepted

Annex

Organization of the co-supervision LESIA/IKI As far as the PHD will be done in 2 institutes, we find it important to mention the following organization. Regular teleconferences between the two groups will be carried out during the 3 years of the PHD project. Moreover, during the periods spent in Paris, supervisors from IKI will visit LESIA. A workshop will be organized by Paris Observatory at CIAS (https://cias.obspm.fr/) during the first visit. During the periods spent in Moscow, supervisors from the Paris Observatory will visit IKI. These visits are important to maintain regular contact between the two teams and allow good development of the PhD. We plan the following time repartition between two institutions:

• 2020 01/10/2020 – 31/12/2020: LESIA, Paris Observatory (3 months)
• 2021 1/01/2021 – 30/06/2021: LESIA, Paris Observatory (6 months) 1/07/2021 – 31/12/2021: IKI, Moscow (3 months)
• 2022 01/01/2022 – 31/03/2022: IKI, Moscow (3 months) 01/04/2022 – 30/09/2023: LESIA, Paris Observatory (6 months) 1/07/2022 – 31/12/2022: IKI, Moscow (6 months)
• 2023 01/01/2023 – 30/06/2023: IKI, Moscow (6 months) 01/07/2023 – 30/09/2023: LESIA, Paris Observatory (3 months)

The place of the defense will be discussed during the PhD.

X-ray metrology for astrophysical and fundamental physics applications (PhD)

Proposition de Projet de Recherche Doctoral (PRD)

Appel à projet IPhyInf - Initiative Physique des infinis 2020

Intitulé du Projet de Recherche Doctoral : X-ray metrology for astrophysical and fundamental physics applications

-------

Directeur de Thèse porteur du projet :

Indelicato Paul, Directeur de Recherche (paul.indelicato@lkb.upmc.fr)

Site : Bureau 207, Couloir 13-23, Campus Pierre et Marie Curie, 4 Place Jussieu 

Unité de Recherche : Laboratoire Kastler Brossel - UMR 8552

Ecole Doctorale de rattachement de l’équipe & d’inscription du doctorant : ED564-Physique en IdF

Co-encadrant :

Trassinelli Martino, Chargé de recherche (martino.trassinelli@insp.jussieu.fr)

Unité de Recherche : Institut des NanoSciences de Paris - UMR 7588

Ecole Doctorale de rattachement : ED564-Physique en IdF

>>> Pour candidater, merci de contacter et/ou d'envoyer vos dossiers aux encadrants dont les emails sont ci-dessus.

Description du projet de recherche doctoral

Introduction & Context

High-precision atomic physics measurements allow to probe a multitude of fundamental physics questions, from quantum electrodynamics to astrophysics, to tests of the standard model. Precision spectroscopy measurements in muonic hydrogen, to which the LKB group has been a main contributor, have led to the “proton size puzzle”, where the proton size obtained from muonic and normal hydrogen showed a 7 standard deviation disagreement^1-3. The problem is still not fully understood. High-precision measurements with crystal spectrometers in highly charged ions have also improved our understanding of bound state quantum-electrodynamics—BSQED (see Ref. 4 for a recent review). Similar techniques applied to “exotic atoms” where an electron is replaced by a muon, electron, pion, or antiproton, have allowed us to test Chiral Perturbation theory for the strong interaction⁵ , and the nucleonantinucleon interaction⁶ . We also used pionic atoms to perform a precision measurement of the pion mass⁷. These systems may also contribute to tests of the standard model. It has been suggested, for example, that measurements in muonic atoms would provide limits on a possible muon-nucleon interaction⁸ mediated by a new 17 MeV/c² “X Boson”, possibly identified by an ATOMKI^9-11 in a series of recent experiments.

On the astrophysics side, improved knowledge of x-ray transition energies and intensities in highly charged ions has become critical for understanding stellar emissions and searching for dark matter. There is an ongoing debate surrounding a possible dark matter signal at 3.5 keV extracted from the HITOMI satellite data ^12-14, show to be most probably x-ray lines from hydrogenlike sulfur in an ion source based atomic physics experiment¹⁵. Another interesting unsolved problem concerns the intensities of the brightest iron lines emitted by some astrophysical objects¹⁶, the Ne-like iron L lines. Their relative intensities have long posed a problem for plasma models ^{17, 18}, a problem has finally been traced back to a strong disagreement between the most advanced atomic theoretical calculations and experiments¹⁹. We have observed similar discrepancies in high-precision reference-free measurements carried out on core-excited Li-like ions with our double crystal x-ray spectrometer on SIMPA (Source d’Ions Multichargés de Paris) in Jussieu²⁰: theoretical predictions do not agree with the measured line intensity ratios.

New quantum technologies are now available for atomic physics that can shed light on these outstanding problems. The project proposed here will use both world-leading X-ray metrology techniques and new quantum transition edge sensor (TES) detectors to make precision measurements of highly charged and exotic atoms for multi-faceted fundamental physics studies. This novel combination of expertise will directly benefit astrophysical applications, as one of the members of the muonic atom collaboration described below (S. Watanabe) is also part of the design group in charge of the new X-Ray Imaging and Spectroscopy Mission satellite—XRISM (http://xrism.isas.jaxa.jp/en/), which will be equipped with a TES detector and launched in 2021. It will perform high-resolution X-ray spectroscopic observations of the hot gas plasma wind that blows through the galaxies. The progress in TES calibration techniques will directly benefit to the analysis of the data collected by XRISM.

Project

The PhD project has three parts. First, highest-precision reference-free measurements on few-electron heavy ions will be performed with the crystal spectrometer at SIMPA in Paris, to explore the problem of line intensity ratios and energies important for QED studies and plasma physics. Second, the candidate will use a quantum sensing detector to contribute to a new measurement on hydrogenlike uranium using the storage ring of the FAIR²¹ facility in Germany, to probe QED in the high-field regime, improving the current accuracy²² by a factor of 5. Finally, the candidate will combine their new expertise with both quantum sensing detectors and crystal spectrometers for precision measurements of transitions between Rydberg states in muonic atoms at J-PARC in Japan. Advanced calculations by the LKB team have recently shown that these exotic atoms offer a complementary and more accurate probe of QED contributions than highly-charged ions, as the nuclear size and nuclear polarization effects are very small in these systems.

Highly charged ions at SIMPA

The first part of the project consists in improving the double crystal x-ray spectrometer on SIMPA to measure highly charged ions (HCI). This spectrometer is a world-unique facility, allowing to perform reference-free ppm-accuracy measurements on highly-charged middle-Z ions^{20, 23-25}. The only other instrument allowing such measurements is at the Max Planck Institute in Heidelberg, but it uses a different method. The candidate will improve the setup by implementing piezo-electric devices for remote-control of the crystal adjustments (the spectrometer is under vacuum). This will save time and allow for a more accurate setup. He/she will also add a second x-ray detector to reduce the impact of the ion source intensity fluctuations. The improved setup will then be used to better understand energies and transition probabilities in some cases for which problems have been identified. We will thus perform high-precision measurements of the 1s2s2p ²P_J→1s² 2s ¹ S_1/2 transitions in elements other than S and Ar, where we observed these problems²⁰ and of the 1s2s2²p ¹P₁→1s²2s^{2 1}P₀ in Be-like Cl and S as a measurement we performed in sulfur seems to indicate an increased disagreement with theory. This will improve our knowledge in particular of Auger shifts and widths of the observed lines. For the astrophysical problem identified in Ne-like iron, we will extend the measurements to Kr and Xe. The study of the evolution of the intensity ratio and energies as a function of Z will enable to better understand the reason for the large observed disagreement. In Xe, we also plan to measure more lines of adjacent charge states to improve our knowledge of more complicated systems. It was realized in a recent work we performed in collaboration with the Max Planck Institute in Heidelberg that the limitation of relativistic theory is preventing us from fully exploiting high-accuracy mass measurements²⁶. A key component of this part of the work will be the utilization of newly-developed Bayesian analysis techniques for disentangling complicated atomic spectra, developed by M. Trassinelli at INSP. ^27-29

Highly charged ions at GSI/FAIR

Several years ago, both PhD supervisors were involved in an accurate measurement of the Lyman α transitions in H-like heavy ions^30-32. In this new project, we will use the new GSI/FAIR²¹ low-energy storage ring CRYRING³³, which is being commissioned this year, to remeasure the 1s Lamb shift in H-like Uranium using radiative-electron capture from the cooler electrons (approved project E138). This is a key measurement to probe high-field QED, complementary to the medium-Z measurements in Paris. This experiment will attain a 5 times higher-accuracy than presently available²², making it finally sensitive to 2- loop QED contributions⁴ . The measurement will use a quantum-sensing microcalorimeter detector based on magnetic transitions ³⁴. First runs of these experiments are planned for spring 2021 or 2022. This is perfect timing for a Ph.D. thesis starting in the fall of 2020, as the student will be able to participate in the ensemble of the experimental setup and data-taking.

Muonic atom precision experiments at J-PARC

In April 2019, we performed a preliminary experiment for QED tests with muonic atoms at J-PARC in Japan, in collaboration with Pr. Azuma and his group from RIKEN, researchers from the university of Tokyo and of the Kavli Institute, and from the NIST in Boulder (HEATES international collaboration). We did the first observation ever of a transition in muonic atoms³⁵ using a high-performance, new-generation quantum sensing TES microcalorimeter detector^{35, 36}. A 5 year measurement program has been accepted to measure high-n circular Rydberg states in muonic atoms, with gains of 2-3 over existing sensitivity to higher-order QED effects. We did a first high-precision measurements on Ne and Ar in January 2020, in the 3-10 keV range. Two new detectors, intended to the 3-35 keV and 3-100 keV range will allow to study heavier elements, Kr and Xe, available for the next run in December 2020 and by the end of 2021, respectively. One key to experimental success is the calibration of the TES detector, which is extremely sensitive. We used a combination of many metallic targets excited with an x-ray tube during our January run. We plan to improve our calibration procedure by measuring transition energies in HCI with the Paris spectrometer, and compare them with the measurements performed with the TES. The candidate will play a central role in designing and performing this new calibration procedure, which will have important implications for our physics program, allowing us to gain another order of magnitude in sensitivity, and can be used for other experiments with TES detectors such as XRISM.

Conclusion

This project is thus, both by its physics objectives and applications, at the interface between atomic physics, low-energy particle physics, tests of the standard model and astrophysical applications. The PhD candidate will perform complementary experiments with advanced, state-of-the art, world unique technologies and instruments to provide the most-accurate atomic data available to date in highly-charged and exotic atoms. The project builds on the world-recognized expertise in relativistic atomic structure and QED calculations of the LKB group to provide the necessary information to exploit the experimental results to their fullest. A complete data analysis will include Bayesian methods developed by the INSP group for model testing, specially adapted for low-statistics exotic atomic spectra.

Role of the two PhD supervisors

P. Indelicato will be in charge of x-ray metrology and muonic atom experiments at J-PARC, and of providing theoretical support in QED and relativistic many-body calculations. M. Trassinelli will be responsible for the GSI/FAIR experiments and for developing tools for data analysis with Bayesian techniques.

Student profile

The PhD student hired in the framework of this project will participate in the conception, construction, improvements, and use of the different experimental set-ups in Paris, at GSI, and J-PARC. Basic programming competencies in ROOT/C++ and Python are appreciated to analyze the TES and DCS data, as well as to use the Bayesian analysis suites. LABVIEW is used for control of some of the instruments. Good mastering of English is also necessary for working in the international collaborations in Germany and Japan.

References

1. R. Pohl, A. Antognini, F. Nez, et al., Nature 466, 213 (2010).
2. R. Pohl, F. Nez, L. M. P. Fernandes, et al., Science 353, 669 (2016).
3. A. Antognini, F. Nez, K. Schuhmann, et al., Science 339, 417 (2013).
4. P. Indelicato, Journal of Physics B: Atomic, Molecular and Optical Physics 52, 232001 (2019).
5. M. Hennebach, D. F. Anagnostopoulos, A. Dax, et al., Eur. Phys. J. A 50, 1 (2014).
6. D. Gotta, D. F. Anagnostopoulos, M. Augsburger, et al., Nuclear Physics A 660, 283 (1999).
7. M. Trassinelli, D. F. Anagnostopoulos, G. Borchert, et al., Physics Letters B 759, 583 (2016).
8. U. D. Jentschura and I. Nándori, Physical Review A 97 (2018).
9. A. J. Krasznahorkay, M. Csatlós, L. Csige, et al., Journal of Physics: Conference Series 1056, 012028 (2018).
10. A. J. Krasznahorkay, M. Csatlós, L. Csige, et al., EPJ Web Conf. 142, 01019 (2017).
11. A. J. Krasznahorkay, M. Csatlós, L. Csige, et al., Physical Review Letters 116, 042501 (2016).
12. F. A. Aharonian and H. Akamatsu and F. Akimoto, et al., The Astrophysical Journal Letters 837, L15 (2017).
13. C. Dessert, N. L. Rodd, and B. R. Safdi, Science 367, 1465 (2020).
14. K. T. Smith, Science 367, 1438 (2020).
15. C. Shah, S. Dobrodey, S. Bernitt, et al., The Astrophysical Journal 833, 52 (2016).
16. F. B. S. Paerels and S. M. Kahn, Annual Review of Astronomy and Astrophysics 41, 291 (2003).
17. P. Beiersdorfer, E. Behar, K. R. Boyce, et al., The Astrophysical Journal Letters 576, L169 (2002).
18. E. Behar, J. Cottam, and S. M. Kahn, The Astrophysical Journal 548, 966 (2001).
19. S. Bernitt, G. V. Brown, J. K. Rudolph, et al., Nature 492, 225 (2012).
20. J. Machado, G. Bian, N. Paul, et al., Physical Review A in press (2020).
21. M. Durante, P. Indelicato, B. Jonson, et al., Physica Scripta 94, 033001 (2019).
22. A. Gumberidze, T. Stöhlker, D. Banaś, et al., Physical Review Letters 94, 223001 (2005).
23. J. Machado, C. I. Szabo, J. P. Santos, et al., Physical Review A 97, 032517 (2018).
24. P. Amaro, C. I. Szabo, S. Schlesser, et al., Radiation Physics and Chemistry 98, 132 (2014).
25. P. Amaro, S. Schlesser, M. Guerra, et al., Physical Review Letters 109, 043005 (2012).
26. A. Rischka, H. Cakir, M. Door, et al., Physical Review Letters 124, 113001 (2020).
27. M. Trassinelli, Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 408, 301 (2017).
28. M. Trassinelli, Proceedings 22, 14 (2019).
29. M. Trassinelli and P. Ciccodicola, Entropy 22, 185 (2020).
30. S. Chatterjee, H. F. Beyer, D. Liesen, et al., Nuclear Instruments & Methods in Physics Research Section BBeam Interactions with Materials and Atoms 245, 67 (2006).
31. H. F. Beyer, T. Gassner, M. Trassinelli, et al., Journal of Physics B: Atomic, Molecular and Optical Physics 48, 144010 (2015).
32. H. F. Beyer, G. Menzel, D. Liesen, et al., Zeitschrift für Physik D 35, 169 (1995).
33. M. Lestinsky, V. Andrianov, B. Aurand, et al., The European Physical Journal Special Topics 225, 797 (2016).
34. S. Kraft-Bermuth, D. Hengstler, P. Egelhof, et al., Atoms 6, 59 (2018).
35. S. Okada, T. Azuma, D. A. Bennett, et al., Journal of Low Temperature Physics 199, in press (2020).
36. W. B. Doriese, P. Abbamonte, B. K. Alpert, et al., Rev. Sci. Instrum. 88, 053108 (2017).

New generation of opacities for astrophysics (PhD)

Proposition de Projet de Recherche Doctoral (PRD)

Appel à projet IPhyInf - Initiative Physique des infinis 2020

Intitulé du Projet de Recherche Doctoral : New generation of opacities for astrophysics

-------

Directeur de Thèse porteur du projet :

Ciardi Andrea, Maître de Conférences des Universités (andrea.ciardi@obspm.fr)

Site : Sorbone Université - LERMA (SU) - 24-34- 5ème étage, Bureau: 520. 4 place Jussieu, Paris 75005

Unité de Recherche : LERMA - UMR 8112

Ecole Doctorale de rattachement de l’équipe & d’inscription du doctorant : ED127-Astronomie&AstrophysiqueIdF

Co-encadrants :

Koenig Michel, Directeur de Recherche (michel.koenig@luli.polytechnique.edu)

Unité de Recherche : LULI - UMR 7605

Ecole Doctorale de rattachement : ED 626 

Delahaye Franck, Astronome Adjoint (franck.delahaye@obspm.fr)

Unité de Recherche : LERMA - UMR 8112

Ecole Doctorale de rattachement : ED 127

>>> Pour candidater, merci de contacter et/ou d'envoyer vos dossiers aux encadrants dont les emails sont ci-dessus.

Description du projet de recherche doctoral

Context

The large scale dynamics and thermodynamics of plasmas can be strongly affected by the interaction with photons. From inertial confinement fusion and laser-matter interaction, to the physics of stellar interiors, being able to model the coupling of plasma and radiation is fundamental. Indeed, one of the most widely used models of plasmas, radiation-magneto-hydrodynamic, treats both plasma and photons as "fluids" that are coupled by one key microscopic transport parameter: the opacity. More generally this quantity enters all radiation transport calculations and it is the results of complex and time-consuming quantum-mechanical (or semi-classical) calculations involving atomic processes in high-energy density plasmas, such as electron impact excitation, photoionization, recombination, photo-excitation and radiative decay. Accurate opacities calculations of plasmas under different physical conditions are fundamental to be able to model and interpret experiments and observations. In that respect, the experimental validation of theoretical opacity calculations is paramount and recent advances in high-energy density plasma physics facilities now allow their direct verification under extreme conditions of temperature and density. Indeed, experiments conducted at Sandia National Laboratory have now yielded precious results on the opacity of Iron in conditions typical of the Solar plasma at the base of the convection zone (Bailey et al. Nature 2015, Nagayama et al. Phys Rev L. 2019). Importantly, these results are actually questioning the ability to calculate such fundamental microscopic parameters. The difference between the measured Fe opacities and all of the existing theoretical calculations disagree by a factor of two. Such discrepancy impacts all the different domains of research where radiative transfer is at play, and could be crucial, for example, to understand the long standing problem of the Solar composition.

Aims

It is therefore important to collect more experimental data and to develop a better theoretical framework for this outstanding problem. 1) Experiments: We are developing an experimental platform to measure opacities with new diagnostics to accurately determine the state of the probed plasma (temperature, density). To probe the plasma condition, we will use a combination of X-ray Thomson scattering diagnostic and light elements spectroscopy. We will benchmark and use this platform to measure opacities for some elements from Si to Ni in order to test our ability to calculate theoretically opacities of open L-shell ions, seriously questioned by SANDIA experiments. This work, in collaboration with the LULI and CEA for a three years program on the GEKKO laser in Japan, and LULI lasers will also pave the path to future opacity experiments on the Laser MegaJoule. 2)Theory: We will build a theoretical framework with an improved state-of-theart suite of codes to calculate raw photoionization cross sections and other radiative data and different approximations for the line broadening. 3) Applications: We will model stellar structure and evolution, from Solar model to Red giants and pulsating stellar candles, will help to quantify the effects of the newly improved opacities and give feedback for future improvement, as well as providing clues as to which new elements should be included in more complete calculations.

Thesis work and student

The student will (i) help develop the new experimental platform with a new set of diagnostics to determine the state of the plasma and perform hydro-radiative simulation to design the experiment. (ii) he will analyze spectroscopic and X-ray Thomson scattering data. (iii) he will study the impact of different theoretical approximations on the computation of raw atomic data and the derived opacities. The student should have a strong background in plasma physics.

Environment

The student will benefit from the supervision from the MUMEO team (Multi Measurement of Opacities project) regrouping experimental and theoretical experts from Sorbonne Universite, LULI, Observatoire de Paris and CEA. The student will take advantage of the measurement campaign granted and programmed at GEKKO XII facility for 2021.

Expertise of the supervisors

Andrea Ciardi: theory and simulations of laser produced plasmas, magneto-hydrodynamics, astrophysics, high energy density physics. In charge of supervising the radiation-hydrodynamics modelling. Supervision at 25%.

Michel Koenig: experimental plasma physics, hydrodynamics and shock physics, astrophysics, planetary physics, high energy density physics. In charge of the experiments. Supervision of the student on the experiments. Supervision at 25%.

Franck Delahaye: theory and simulations of atomic physics, opacities (Member of the International collaboration The Opacity Project - The Iron Project), stellar modeling. In charge of the supervision of the modelling of the experimental spectra. Supervision at 50%.

Selected publications of the proposing team

1. Albertazzi, B. et al., "Experimental characterization of the interaction zone between counter propagating Taylor Sedov blast waves", Physics of Plasmas 27, 022111 (2020)
2. Khiar, B. et al. "Laser-produced magnetic-Rayleigh-Taylor unstable plasma slabs in a 20 T magnetic field", Physical Review Letters 123, 205001 (2019)
3. Filippov, E. D., "X-ray spectroscopy evidence for plasma shell formation in experiments modeling accretion columns in young stars", Matter and Radiation at Extremes 4, 064402 (2019)
4. Hare, J. D., et al, "An Experimental Platform for Pulsed-Power Driven Magnetic Reconnection", Physics of Plasmas 25, 055703 (2018)
5. Van Box Som, L., et al, "Numerical simulations of high-energy flows in accreting magnetic white dwarfs", Monthly Notices of the Royal Astronomical Society, Volume 473, Issue 3, Pages 3158–3168 (2018)
6. Michel, Th.; Albertazzi, B.; Mabey, P.; Rigon, G.; Lefevre, F.; Van Box Som, L.; Barroso, P.; Egashira, S.; Kumar, R.; Michaut, C.; Ota, M.; Ozaki, N.; Sakawa, Y.; Sano, T.; Falize, E.; Koenig, M., "Laboratory Observation of Radiative Shock Deceleration and Application to SN 1987A"; ApJ, Volume 888, Issue 1, article id. 25, 5 pp. (2020)
7. P. Mabey, B. Albertazzi, G. Rigon, J. R. Marquès, C. A. J. Palmer, J. Topp-Mugglestone, P. Perez-Martin, F. Kroll, F.-E. Brack, T. E. Cowan, U. Schramm, K. Falk, G. Gregori, E. Falize, and M. Koenig,"Laboratory study of bilateral supernova remnants and continuous MHD shocks",Accepted. To ApJ
8. Delahaye F, Badnell, N.R., Ballance C.P. et al., “A quantitative comparison of opacities using the distorted wave and the R-matrix methods: Fe XVII case” submitted april 2020 to MNRAS
9. Badnell, N. R., Bautista M.A., Butler K. et al. ”Updated opacities from the Opacity Project” MNRAS. Vol 360 pp458-464, 2006
10. Delahaye, F. & Pinsonneault, M. H ”The Solar Heavy-Element Abundances. I. Constraints from Stellar Interiors”, ApJ vol 649 p 529, 2006

Qui suis-je ? L'interview... des membres de la Fédération PLAS@PAR

Dans la dernière newsletter de PLAS@PAR, un membre de la fédération à répondu aux 6 questions ci-dessous sans donner son identité, aviez-vous découvert de qui il s'agissait ? Nous levons le mystère aujourd'hui...

ÉNIGME

1. Je suis... numéricien
2. J’étudie... les plasmas spatiaux
3. Si j’étais un plasma, je voudrais être... une magnétosphère planétaire
4. Si les plasmas étaient une œuvre, ce serait... un poster de Steve Thomas (https://www.stevethomasart.com/spacetravel), sinon David Bowie – Life on Mars
5. Si les plasmas étaient une couleur, ce serait... Rouge (comme Mars)
6. Si les plasmas étaient un sport, ce serait... un sport collectif Basket / Rugby / Foot (dont le comportement d’ensemble modifie les actions individuelles et réciproquement)

---------------

INTERVIEW

Bonjour Ronan Modolo, vous êtes désormais démasqué ! Pouvez-vous nous en dire en peu plus sur votre parcours ? 

J’ai effectué ma thèse au CETP (Centre d'étude des Environnements Terrestre et Planétaires) sous la direction de Gérard Chanteur sur la modélisation des interactions vent solaire-Mars et plasma kronien –Titan (2001-2004). Après une année en tant qu’ATER à l’UVSQ (Université de Versailles Saint-Quentin-en-Yvelines), j’ai bénéficié d’un post-doc à l’Institut de Physique Spatial Suèdois –Uppsala, puis à l’Université d’Iowa, pour travailler sur les données des sondes Cassini et Mars-Express, en particulier sur les mesures d’une sonde de Langmuir et d’un radar ionosphérique. Depuis 2008, je suis MCF (maître de conférences) à l’UVSQ et au LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales) et je poursuis mes activités en lien avec les missions spatiales.

Pouvez-vous en dire un peu plus sur vos recherches actuelles en physique des plasmas ?

Tous les objets du système solaire sont plongés dans un plasma non collisionnel qui interagit avec eux en transférant une partie significative de sa quantité de mouvement et de son énergie dans leur atmosphère. Ce transfert est particulièrement efficace pour les objets faiblement magnét

isés (Mars, Vénus, Titan et les comètes) et pour les objets possédant une magnétosphère très confinée (Mercure, Ganymède, …). Cette interaction contribue à l'érosion de ces enveloppes gazeuses et participe à la dynamique atmosphérique.

Je me suis attaché à l'étude des interactions plasma -neutre dans les environnements planétaires de ces objets en utilisant deux moyens d'étude : un volet de modélisation et de simulation numérique, et un volet d'analyse de données spatiales, en soutien aux missions au spatiales en opération ou en préparation. 

Pour explorer les environnements plasma planétaires, cliquez ici !

Figure 1 : L’environnement plasma de Ganymède (premier plan), une lune de Jupiter (arrière-plan), illustré par le modèle LatHyS ou les plans de coupes représentent la densité électronique du plasma et l’environnement magnétique illustré par les lignes de champ magnétique connectées à la lune.
Crédit : CNES/CDPP/GFI/LATMOS

Pouvez-vous partager avec nous les références de vos dernières publications ?

- Modolo et al, 2018, The LatHyS database for planetary plasma environment investigations: Overview and a case study of data/model comparisons, Planetary and Space Science, doi : 10.1016/j.pss.2017.02.015

- Romanelli et al, 2018, Responses of the Martian Magnetosphere to an Interplanetary Coronal Mass Ejection: MAVEN Observations and LatHyS Results, Geophysical Research Letters, doi : 10.1029/2018GL077714

- Leclercq et al, 2016, 3D magnetospheric parallel hybrid multi-grid method applied to planet-plasma interactions, Journal of Computational Physics, doi : 10.1016/j.jcp.2016.01.005

Pouvez-vous nous en dire un peu plus sur les actions d’enseignement que vous menez ?

En tant qu’enseignant-chercheur, j’assure des enseignements couvrant les cycles Licence et Master. Je participe aux enseignements de physique en Licence (optique, électrocinétique, mécanique, …) mais également de calcul scientifique et méthodes numériques et des Travaux Pratiques en physique des plasmas spatiaux. Depuis quelques années j’ai centré mon activité sur l’enseignement en Licence et plus particulièrement en première année avec la participation et la mise en place de dispositifs d’aide à la réussite (amélioration de la transition lycée – université, diversification des modalités pédagogiques, remise à niveau pour les étudiants en difficultés, exploitation et développements de ressources numériques, …). En tant que responsable de formation, j’accompagne les étudiants de Licence dans leur parcours et la construction de leur poursuite d’études. 

Sur quel(s) site(s) travaillez-vous ?

Je suis multi-sites avec des activités d’enseignement et de responsabilité pédagogique qui ont lieu sur le campus de l’UFR des Sciences de l’UVSQ à Versailles, et des activités de recherche réparties entre le site de Guyancourt de l'OVSQ (Observatoire de Versailles Saint-Quentin) et le campus Pierre et Marie Curie de Sorbonne Université (avec un centre de masse sur Jussieu où se trouve le reste de l’équipe interaction plasma-neutre).

Quel est votre rôle au sein de la communauté PLAS@PAR ?

Le LATMOS fait partie des nouveaux arrivants qui ont rejoint la Fédération. Mon objectif est de consolider des liens entre notre équipe et les laboratoires de plasmas spatiaux et d’établir de nouvelles collaborations autour des processus microphysique (ionisation, collisions) et le développement d’outils numériques. Je souhaite également m’investir dans des actions d’enseignement et de vulgarisation. Je participe au Bureau (conseil) de PLAS@PAR.

Pouvez-vous nous expliquer les actions que vous menez auprès du grand public ?

Je participe de manière ponctuelle à des actions de communication, d’animation et de diffusion scientifique auprès du grand public et des scolaires. Cela se fait sous différentes formes :

-       Conférence grand public dans le cadre de la Fête de la science
-       Exposition photos (ex : Exploration du système solaire : de l’Espace au numérique à la Médiathèque de Saint-Quentin)
-       Visites et animations dans des écoles primaires
-       Participations aux cordées de la réussite (Animation avec des stagiaires de licence au collège Pasteur de Mantes-la-Joly, conférence aux collégiens)
-       Participations à l’accueil de stagiaires de collège au LATMOS
-       Communiqués de presse
etc.

Si PLAS@PAR doit relever un défi pour les 5 prochaines années, quel est-il selon vous ?

Les défis sont multiples mais si je ne peux en citer qu’un je dirai d’accroitre la visibilité de nos activités de recherche auprès du grand public et des étudiants. Le Labex PLAS@PAR a permis de mettre en place un grand nombre d’actions structurantes de médiation scientifique qu’il faut pérenniser et enrichir. 

Un dernier mot ?

Je suis très heureux d’avoir pu rejoindre la Fédération et de pouvoir bénéficier de la richesse de collaborations du réseau. J’ai hâte de participer aux actions interdisciplinaires, d’enseignement et de visibilité de notre communauté.

Merci beaucoup Ronan Modolo ! À qui le tour ?

Labex PLAS@PAR Activity Report 2012-2019

The PLAS@PAR Activity Report 2012-2019 is now available! We thanks all the contributors, this book will be useful in the coming years for our Federation. It summarizes the actions realized concerning research, education and teaching, industry, communication and outreach.

Abstract of the editorial by Pascal Chabert, Dominique Vernhet, Alain Dubois & Chantal Stehlé:

Labex PLAS@PAR has been a wonderful common scientific enterprise developing strong links between scientists from different laboratories and horizons, giving new impetus to research through many PhDs and postdocs, and creating a strong and visible community in the Ile-de-France region. This community will continue to consolidate and grow in the future.

We are grateful to our many colleagues for the imagination, effort and commitment they have brought to PLAS@PAR to make it a successful scientific and human adventure.

We offer our warm gratitude to University Pierre and Marie Curie (now Sorbonne Université) for its strong support since the beginning of the project. We would also like to thank our trustees, as well as all of the members of the International Scientific Board, for their encouragement and advice during this 8-year period.

Activity Report (planche)

Activity Report (page) 

L'Université inter-âges c'est en ce moment !

Christophe Prigent, enseignant-chercheur à l'INSP (Institut des NanoSciences de Paris) mène les deux premières sessions (puis les sessions 6 et 7) de l'Université inter-âges qui accueille cette année 50 participants pour un cycle 100% plasma : "Voyage au coeur du 4ème état de la matière".
Pour cette deuxième session introductive, Christophe a emprunté des instruments de la collection de Physique de Sorbonne Université et a réservé pour les participants une bonne surprise ! Ils pourront (sur inscription) visiter la semaine prochaine ou la semaine suivante, au choix, la Source d'Ions Multichargés de Paris sur le campus Pierre et Marie Curie.

La semaine prochaine le cycle de conférences continue avec Laurence Rezeau (Professeure à Sorbonne Université, Laboratoire de Physique des Plasmas). La session portera sur "Le Soleil et la terre, une relation singulière". Thierry Dufour (enseignant-chercheur, Laboratoire de Physique des Plasmas) donnera les 3 derniers cours liés à l'industrie, la médecine et l'environnement.

Toute l'information ici

La machine électrostatique de Wimshurst - Collection de Physique de Sorbonne Université

Summer school 2020: Registration open!

It's time for registration!

The Solar Orbiter mission: immediate liftoff

On February 10, 2020, thanks to the European Space Agency (ESA), the Solar Orbiter space mission has been launched from Cap Canaveral.

The mission launched with the ATLAS V rocket (in collaboration with NASA) carries 10 scientific intruments, among which several have been designed in 2 laboratories members of the PLAS@PAR Research Federation in Plasma Physics: LESIA¹ (Laboratoire d'Études Spatiales et d'Instrumentation en Astrophysique) and LPP² (Laboratoire de Physique des Plasmas).

Artistic view of the Solar Orbiter’s probe, its solar panels, antennas and the mast on which several of the in-situ measuring instruments are attached.
Credit: ESA/ATG medialab
from https://sci.esa.int/web/solar-orbiter/-/artist-s-impression-of-solar-orbiter-1

A long-standing quest

There has been a few probes orbiting the Sun but nothing similar to what Solar Orbiter will achieve in the coming decade.
In the late 70’s, the Helios mission came nearby in the ecliptic plane. Then the ULYSSES mission in the 90’s flew over the poles of our star. But none of them had Solar Orbiter capabilities to look at the Sun and at the same time to measure the solar wind escaping from it.

Why did ESA develop such an ambitious mission?

Solar Orbiter is a mission that will last 7 to 10 years, it will fly over Venus several times and spend long periods near our star studying questions related in particular to the heliosphere and the solar winds, that are long-standing investigations.

Solar Orbiter is an emblematic and very ambitious mission for ESA because of its proximity with the Sun. Parker Solar Probe and Solar Orbiter will work together: the european probe will help to visualize the space environment in which the American probe will collect data at an even closer distance from the sun (7 million km).

Solar Orbiter’s scientific goals

During the overflights of Venus, Solar Orbiter will have to gradually lower its orbit. The satellite will gradually increase its inclination compared to the ecliptic plane to reach an inclination up to 33 degrees. The mission should answer questions such as:

·      How does the magnetic field emerge from the inside and what is its impact on the solar atmosphere?
·      What are the mechanisms involved in the formation of the corona and the solar wind?
·      What are the physical processes explaining the eruptive activity of the sun?

Understanding the mechanism of solar flares would help to better predict solar storms and the disturbing effects on Earth and on our satellites.

LPP and LESIA contributions

6 French laboratories participated in the design of part of the mission’s scientific equipment, 2 laboratories members of PLAS@PAR Research Federation actively contributed to the development of several instruments: LESIA and LPP.

The Laboratoire de Physique de Plasmas (LPP) designed and produced both the RPW LFR (Low Frequency Receiver) subsystem for on-board processing of electromagnetic wave measurements and the electron detection system of the EAS (Electron Analyzer Sensor) spectrometer of the SWA (Solar Wind Analyzer) instrument. The LFR analyzer is based on a low power FPGA digital signal processor. It reduces the amount of data transmitted to the ground while optimizing the scientific value. It delivers a wide range of products ranging from simple waveforms to sophisticated spectra. The EAS detection system incorporates new-generation ASIC-type electronics that have miniaturized the instrument while providing high angular resolution measurements of the electrons in the solar wind.

The Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique (LESIA) is responsible (PI) for the RPW (Radio & Plasma Waves) instrument developed and designed by the Centre national d'études spatiales (CNES).
The RPW instrument consists of a complex electronic box of 7 kg in the heart of the probe, well protected by its heat shield, and connected to several types of external sensors: the magnetic sensor SCM, located on the mast of the satellite with a distance of two meters from the platform, and three 6.5 m long electric antennas. The instrument measures the magnetic and electric fields in the vicinity of the probe in order to study the dynamics of the solar wind, this jet of charged particles - plasma - emitted by our star.
The LESIA is also involved in the STIX spectro-imager which will provide spectra and X-ray images produced by hot plasmas and energetic electrons produced during solar flares.

¹Observatoire de Paris – PSL/CNRS/ Sorbonne Université/Université de Paris

²CNRS/École Polytechnique/Sorbonne Université/Université Paris-Saclay/Observatoire de Paris – PSL

Read more:

Press release (CNES/CNRS/CEA): http://www.cnrs.fr/fr/la-sonde-europeenne-solar-orbiter-quittera-la-terre-en-direction-du-soleil-le-10-fevrier-2020
Press release (Observatoire de Paris): https://www.obspm.fr/IMG/pdf/cp_op-psl_solar_orbiter_analyseur_rpw_def.pdf

Le Figaro :

Watch the interview of Matthieu Berthomier (LPP) and Guillaume Aulanier (LESIA) here!

Sources:

https://www.youtube.com/watch?v=ciidZq_oM7Q
https://www.lpp.polytechnique.fr/-Solar-Orbiter,273-
https://lesia.obspm.fr/Solar-Orbiter.html

Happy new year 2020!

All the PLAS@PAR direction team wishes you a happy new year 2020!

2020 is a new start for PLAS@PAR with the creation of a new structure that will take over the actions initiated by the Labex: a Research Federation in Plasma. On January 13 (morning), the last Scientific day of PLAS@PAR Labex will be held at Pierre et Marie Campus, this event will be followed by a General meeting at 2pm:

- general information about the federation
- first discussions on the work's organization
- first discussions on the orientations

We are looking forward to see you all!

Plasma physics training for future teachers in middle and high schools!

Sharing knowledge with new generations

Photo credit: Gaëtan Gauthier, LPP

"Les plasmas (sont encore) dans tous leurs états"

Once again, 2020 will start under the sign of education!
Through a 2-day training on January 8 & 15 PLAS@PAR organizes a workshop for future professors from the "Master des Métiers de l'Enseignement, de l'Education et de la Formation (MEEF), parcours physique-chimie" at Sorbonne University. 

Because we think that plasma physics can be easily taught in school, our goal is to give some simple key information and tips to allow teachers to talk about the 4^th state of matter in the classroom.

New this year: new programs in high school was an opportunity to introduce the Python programming language. Through simple examples of Python scripts, we offer a dedicated session on solving plasma physics problems (from the movement of particles to chaos).

Training program (full program is available here – in French):

·       Discussion & presentations about all types of plasmas
·       Hands-on experiments
·       Visits of research facilities and experiments 

This year 6 researchers from LPP, INSP & LERMA are involved in this training!

An arts & sciences workshop at Radioastronomy station of Nançay!

Radioastronomy station of Nançay (Observatoire de Paris) will host a workshop with ENSA Bourges' students!

Solitude sidérale - Au coeur des ondes (Workshop)

Following the conference of Philippe Zarka (LESIA & USN, Observatoire de Paris - CNRS - PSL) at ENSA Bourges on October 30, 2019, who was invited by Stéphanie Jamet, Ingrid Luche and Benjamin L. Aman (ENSA), a workshop is now organized, thanks to Stéphanie Jamet (ENSA) with Dominique Blais (artist & lecturer at École des arts de la Sorbonne - Université Paris I Panthéon-Sorbonne) and Philippe Zarka, at the Radioastronomy station of Nançay from November 19, 2019 to November 22, 2019. 10 students will participate!

Abstract (in french) - Solitude sidérale - Au coeur des ondes - Par Dominique Blais

Sur une proposition de Stéphanie jamet, en présence de Philippe Zarka, astrophysicien

"La plongée dans l’espace-temps particulier qu’est la station de Radioastronomie de Nançay ouvre sur une interrogation de la solitude humaine au-delà même d’un territoire circonscrit et connu. L’isolement obligé du lieu serait-il à l’image de la nécessaire solitude du chercheur ?
Dans le silence, le scientifique sonde en effet l’indicible et l’inaudible de l’espace avec, certainement, toujours ce secret espoir d’entendre une présence « extra-terrestre ».
Comment en rendre compte alors ?"

PLAS@PAR is happy to support this interdisciplinary project arts & sciences called "sidereal loneliness".

Photo credit: C. Penin

Arts & plasma sciences: the project paved the way for new creations!

We are happy to hear some good news from Aurélie Pertusot who will present her work at the exhibition Science Friction 2.0!

Aurélie Pertusot was one of the 4 artists selected in 2018 for the Micro-residency artists and scientists at the Radioastronomy station of Nançay (Observatoire de Paris) & presented her work at the exhibition Campus - Arts and plasma science: an experience of ionized matter, a collaboration between PLAS@PAR, Sorbonne University and the Centre Pompidou.

This residency was a unique opportunity to create links between artists and scientists and open new collaborations! The exhibtiion Science Friction 2.0 is a good example: Aurélie Pertusot will present the sound installation "une certaine musique des sphères", which is the result of a collaboration with Philippe Zarka, Director of Research at the CNRS (LESIA, Observatoire de Paris).

Dates: 07.11.19 - 20.12.19
Location: My monkey, 111 Rue Charles III, 54000 Nancy (fr)
Vernissage: 07.11.19, 18:30

We whish you a lot of success!

To know more about the exhibtiion: http://mymonkey.fr/wordpress/11161-2/

Arts & Sciences: Philippe Zarka, invited speaker at ENSA Bourges

Philippe Zarka gives a conference on October 30, 2019, 5pm, at ENSA Bourges !

Les chants du cosmos

Abstract (in french)

"Le silence des espaces infinis m'effraie" écrit Pascal, tandis que le film Alien rappelle que "dans l'espace on ne vous entend pas crier". Quelle est donc cette "musique des sphères" que les radiotélescopes "écoutent". Je parlerai des ondes sonores et lumineuses, de leurs relations et de leurs traductions mutuelles, pouvant donner à entendre une transcription des ondes radio cosmiques.
J'aborderai ensuite quelques unes des recherches conduites à l'aide de ces ondes radio: aube cosmique, mystérieux "sursauts radio rapides" venus du fin fond de l'espace, exoplanètes dans notre voisinage galactique, signaux extraterrestres. Les premières questionnent l'histoire de l'Univers: où sommes nous entre aube et crépuscule ? Les secondes posent la question d'une autre vie dans cet Univers, qui mettrait fin à notre solitude cosmique ? Abordant ces vastes questions de plus en plus en équipe, le chercheur en est-il moins isolé ?

Speaker

Philippe Zarka, LESIA & USN, Observatoire de Paris - CNRS - PSL

Après un doctorat à l’Université de Paris VI, Philippe Zarka est entré au CNRS en 1985. Affecté à l’Observatoire de Paris, il y a abordé la radioastronomie, l’étude des planètes et la physique des plasmas. De l'étude des planètes du système solaire en ondes radio depuis l'espace (de Voyager à Cassini) et le sol (à Nançay), il est passé aux exoplanètes, dont il a prédit les émissions radio qu'il tente de détecter avec les plus grands radiortélescopes au sol: Ukraine, Pays-Bas, et aujourd'hui en France où il dirige la construction d'un des plus puissants radiotélescopes basses fréquences du monde: NenuFAR. Directeur de Recherche au CNRS et directeur-adjoint de la Station de Radioastronomie de Nançay, il mène des activités de recherche scientifique (~300 articles et quelques ouvrages), de formation (cours, conférences), d'encadrement (thèses) et de vulgarisation. Il a par ailleurs imaginé une méthode originale de traduction sonore des ondes radio cosmiques, aujourd'hui matière à collaborations avec des artistes.

Philippe is invited by Stéphanie Jamet, Ingrid Luche and Benjamin L. Aman (ENSA).

PLAS@PAR is happy to support this interdisciplinary project arts & sciences called "sidereal loneliness".

Photo credit: C. Penin

Elmar Slikboer awarded by the 2019 Pellat Prize

Elmar Slikboer, researcher at LPP has been awarded by the 2019 René Pellat Prize from the SFP (Société Française de Physique, plasma division), congratulations!


This prize is awarded once a year to a young researcher or a young researcher who has done exemplary work in plasma physics (hot, cold, natural plasma) and is awarded this year to a co-supervised PhD student at LPP.

Elmar Slikboer worked on "Investigation of Plasma Surface Interactions using Mueller Polarimetry" with 3 laboratories to complete his thesis: a co-supervision of A. Sobota of Eindhoven University (TU / e), E. Garcia Caurel of LPICM and O. Guaitella of LPP (École Polytechnique).

Read more here.

Lina Hadid awarded by the 2019 Vincenzo Ferraro Prize

Lina Hadid, who did her PhD at LPP under the supervision of F. Sahraoui has been awarded by the 2019 Vincenzo Ferraro Prize, congratulations!


Lina Hadid has been awarded the Vincenzo Ferraro 2019 Prize, which is awarded once a year to a young researcher who has completed a thesis and major international research work in space plasmas physics. In addition, Lina will join the LPP in January 2020 after having been recruited in the CNRS 2019 competition (Section 17 - Astrophysics).

Read more here.

The 2019 CNRS Innovation Medal is awarded to Ane Aanesland

Ane Aanesland, researcher at LPP and former member of the PLAS@PAR steering committee has been awarded by the 2019 CNRS Innovation Medal, congratulations!


A new success for Thrustme the start-up founded in 2017 by Ane Aanesland and Dmytro Rafalskyi, specialized in the propulsion of miniaturized satellites with a main objective: to enable an economically and environmentally sustainable space industry. Both, they developed 2 major innovations to reduce the size of the thrusters used by satellites in low Earth orbit:

First, they imagined new ways of storing, processing and accelerating iodine, they have shown that this inexpensive ergol, could in solid form, replace xenon, a gas widely used for plasma propulsion systems. Secondly, they designed a unique technology that accelerates both positive ions and electrons, instead of having a different electrode to emit each type of particles.


Thrustme has benefited from PLAS@PAR support to initial scientific investigations at LPP just before its launch.

Photo credit: Thrustme

Meet with Mélissa Menu, PLAS@PAR young researcher - LPP, LERMA PhD student

EPISODE 13

---

"PLAS@PAR allow us to (...) meet scientists of other fields and this gives the opportunity to have some other ideas, another point of view (...)"

After a Master degree in Astronomy and Astrophysics at Observatoire de Paris, Mélissa Menu joined Sébastien Galtier (LPP) and Ludovic Petitdemange (LERMA) for a PhD funded by PLAS@PAR. Since 2016, she is working on Rotating turbulent dynamos and will defend her thesis in few months.

In this episode, Mélissa explains what is a dynamo, then she talks about her research, her results and the benefits of belonging to the PLAS@PAR research community!

Revelations of the moon Europa

The significant impact of Jupiter's magnetic field

Photo credit: NASA/JPL-Caltech/SETI Institute

Who is Europa?

In fews words, Europa is a small satellite of Jupiter, the sixth by distance and the second among the Galilean satellites (Io, Europa, Ganymede).
 
Size: 3,121 kilometers (one-fourth the diameter of Earth)
Temperature: - 150°C
Atmosphere: mainly composed of O₂
Structure: Its surface is composed of ice and is the slickest of all the solar system. In the 1990’s, the Galileo space mission revealed the presence of deep liquid ocean under the ice ; in September 2016, the Hubble Space Telescope (NASA) observed water geysers on its surface.

These discoveries triggered questions about a potential life in Europa. The NASA is planning to investigate this hypothesis thanks to a new space mission that might be launched in 2020-2030.

Europa awakens the curiosity of the scientific community! 

If data from space missions got evidences of the presence of oceans in the moons of Jupiter (awaiting confirmation by a future mission), we didn’t have much information about the mechanisms and the geological consequences on these moons and more particularly on Europa.

The influence of Jupiter’s magnetic field on ocean dynamics : a first and huge step in the understanding of Europa 

Ludovic Petitdemange, CNRS researcher at LERMA (Laboratoire d’Études du Rayonnement et de la Matière en Astrophysique et Atmosphères) and Christophe Gissinger CNRS researcher at LPENS (Laboratoire de Physique de l’École Normale Supérieure), started their research about Europa in 2016.

They focused their research on the oceanic motions and highlighted a physical phenomenon still ignored by scientists.

To reach their goals, they did numerical simulations of Europa’s interior (a model) thanks to data from space missions. They found that Jupiter influences the dynamics of oceans : « Jupiter’s magnetic field generates a retrograde oceanic jet at the equator, which may influence the global dynamics of Europa’s ocean and contribute to the formation of some of its surface features by applying a unidirectional torque on Europa’s ice shell. »

 



 

Fig.1 shows that the rotation of Jupiter’s magnetic field induces a planetary scale recirculation, and generates strong upward and downward turbulent motions at the equator (Fig. 1c). But the most striking feature is the generation of a powerful oceanic jet propagating westward (Fig. 1a and 1b), and localized in the moon’s equatorial region.

More detailed information in the scientific paper here

Next research steps

These results brought new ideas to the scientists and raised new questions. Ludovic and Christophe are now planning to explain the link between the liquid and the geological features observed on Europa. According to them, It would also be interesting to do simulations which cover all the parameters (it means a more detailed model of Europa) such as Jupiter's tidal effect on Europa because we don’t know yet precisely how theses forces are acting/reacting together.


>>> Congratulations Ludovic and Christophe & Good luck! We're waiting to hear from this great astrophysics project!



References:

Gissinger, C., Petitdemange, L., 2019. A magnetically driven equatorial jet in Europa’s ocean. Nature Astronomy. https://doi.org/10.1038/s41550-019-0713-3
Article grand public, National Geographic: https://www.nationalgeographic.fr/espace/2019/03/le-champ-magnetique-de-jupiter-fragilise-sa-lune-europe
About Europa in NASA website: https://solarsystem.nasa.gov/moons/jupiter-moons/europa/in-depth/