Publications

2026

• Mercury's Eccentric Orbit as a Driver of Significant “Seasonal” Change in Upstream Solar Wind Forcing
  
  • Dewey Ryan M
  • Jackman Caitriona Mary
  • Rojo Mathias
  • Hadid Lina Z
  • Sánchez‐cano Beatriz
  • Bowers Charles F
  • Raines Jim M
  • Lepri Susan T
  • Livi Stefano
  • Coburn Jesse T
  • Aizawa Sae
  • Rivera Yeimy J
  • Sun Weijie
  • Zhao Jiutong
  • Slavin James A
  • Heyner Daniel
  • Hollman Daragh M
  • Shane Alexander D
  Geophysical Research Letters, American Geophysical Union, 2026, 53. <div><p>Mercury experiences the most intense and variable solar wind (SW) conditions in the solar system due to its close, eccentric orbit about the Sun. In addition to variation driven by coronal source and solar cycle, the SW arriving at Mercury varies periodically as the planet's heliocentric distance changes by over 50% per orbit. We use 30 years of SW measurements near Earth and scale them to Mercury's orbital distance to determine the importance of this "seasonal" change in the SW. We find the seasonal change to be substantial, systematic, and significant, and that it dominates over other sources of variability (e.g., fast vs. slow SW) and even exceeds the relative change at Earth from ICMEs compared to the ambient SW. As a result, Mercury's magnetosphere is expected to exhibit substantial seasonal effects.</p></div> <div>Plain Language Summary<p>The solar wind (SW) is the outermost extent of the Sun's atmosphere, and it flows out supersonically to fill the solar system. The characteristics of the SW vary due to the region of the Sun that produced it as well as where in the solar system it is measured: as it flows away from the Sun, the SW expands and cools so its density decreases sharply. The planet Mercury experiences a high variation in the SW that arrives at it due to these various effects. Mercury's orbit is non-circular so it experiences the strongest "seasonal" change in the SW as it moves closer and further from the Sun. In this study we compare this seasonal change in the SW at Mercury to other sources of variability. We find that the seasonal change affects the characteristics of the SW more than these other sources.</p></div> (10.1029/2026gl123323)
  DOI : 10.1029/2026gl123323
• Chromosphere of the quiet Sun: II. Atmospheric response to small-scale magnetic flux emergence
  
  • Noraz Q.
  • Carlsson M.
  • Aulanier Guillaume
  Astronomy & Astrophysics - A&A, EDP Sciences, 2026, 710, pp.A175. Context. The couplings between the photosphere, chromosphere, and corona in the quiet Sun (QS) are governed by a complex interplay between magnetic structuring, heating, mass-loading, and radiative cooling. The current constraints on how this balance responds to variations in small-scale magnetic flux are limited. Aims. We investigate how chromospheric heating and the thermodynamic response of higher atmospheric layers vary as a function of small-scale magnetic flux emergence under QS conditions. Methods. We performed a parametric set of 3D radiative-MHD simulations with the Bifrost code, starting from a weakly magnetised quiet-Sun reference model and injecting horizontal magnetic flux of increasing amplitude into the sub-surface convection zone. We analysed the resulting chromospheric dynamics, heating, mass-loading, and coronal response in quasi-static regimes. Results. Chromospheric temperatures and mechanical heating rise monotonically with increasing magnetic-field strength. Although the fractional contribution of shocks decreases from 23 to 5%, reconnecting current sheets (CSs) continue to remain steady at about 50%. In contrast, the temperature at the base of the corona exhibits a non-monotonic response, reaching a maximum at intermediate magnetic amplitudes and decreasing for the strongest-field case. We show that stronger magnetic-field strength increases chromospheric heating, thereby increasing the coronal-base density through efficient mass-loading, and amplifies radiative losses. These density-driven radiative losses dominate the coronal energy balance and, thus, lead to reduced coronal-base temperatures despite increased heating. Conclusions. Our results demonstrate the sensitivity of chromospheric structure and dynamics to small-scale flux emergence and its key role in regulating coronal thermodynamics. In particular, this study has revealed a non-monotonic thermodynamic response in the upper atmosphere: stronger heating in the chromosphere can paradoxically lead to lower coronal temperatures as increased mass-loading enhances radiative losses. This result illustrates the chromosphere’s role as a thermodynamic gatekeeper, warranting further investigations of realistic flux-emergence models, as well as surface-to-corona parametrisation across various magnetic configurations, relevant to global solar wind models and space weather forecasts. (10.1051/0004-6361/202660067)
  DOI : 10.1051/0004-6361/202660067
• Transport Modelling for Fusion Devices Using Reduced Models for Turbulence
  
  • Guillon Pierre
  , 2026. The goal of this thesis is to develop and improve reduced models for turbulent transport in tokamak plasmas, using the minimal non-trivial model for instability-driven tokamak plasma turbulence: the Hasegawa-Wakatani (HW) system. Despite its simplicity, this two-dimensional fluid system already displays complex phenomena observed in more realistic systems, such as zonal flows (ZFs) as an example of self-organisation, and a transition from turbulence to ZFs as its linear parameters are varied.First, the transition is explored in details, and seen as a phase transition between a ``hot'' disordered state, and a ``colder'', one-dimensionalised, organised state. Defining the fraction of zonal energy as the order parameter, and the ratio of linear parameters as the control parameter, a sharp transition is observed that moreover exhibits a hysteresis loop. The hysteresis is interpreted as a consequence of ZFs stabilising the system once they are formed, and requiring some energy akin to latent heat in order to collapse. The transition is then reproduced in a system reduced to a few Fourier modes. A theoretical understanding for the transition in that model is provided.The particle flux-driven HW system is then considered, in which the mean density profile evolves in response to the turbulent flux and external sources. To perform pseudo-spectral simulations of a flux-driven system with non-periodic boundary conditions, the P-FLARE code is developed, which relies on the penalisation method. Introducing a source of density, close to the threshold of the transition previously observed, results in sandpile-like critical behaviour and profile stiffness. The latter is argued to be a manifestation of the hysteresis in the ZF level.Finally, Poloidally Truncated Models (PTMs), based on a severe truncation of Fourier modes along the poloidal direction, while retaining the full radial direction, are investigated. It is found that at least 4 poloidal modes, distributed around the most unstable mode, are needed to correctly reproduce direct numerical simulation (DNS) results in both fixed-gradient and flux-driven systems.
• Progress and innovations in the TCV tokamak research programme
  
  • Theiler C.
  • Adamek J.
  • Agostini M.
  • Alberti S.
  • Alberti G.
  • Aleiferis S.
  • Alessi E.
  • Anastassiou G.
  • Andrèbe Y.
  • Antonenas Y.
  • Apruzzese G.M.
  • Aucone L.
  • Auriemma F.
  • Ayllon-Guerola J.
  • Aymerich E.
  • Bagnato F.
  • Bairaktaris F.
  • Balestri A.
  • Ball J.
  • Balugani S.
  • Baquero-Ruiz M.
  • Bardsley O.
  • Battey A.F.
  • Bechtle S.
  • Bernert M.
  • Bin W.
  • Blanchard P.
  • Boedo J.
  • Bolzonella T.
  • Bonalumi L.
  • Bonisolli M.
  • Bosman T.
  • Bouffet-Klein R.
  • Boyer M.D.
  • Bramucci L.
  • Braunmüller F.
  • Breizman B.N.
  • Brida D.
  • Brown B.
  • Brunner S.
  • Buchli J.
  • Buermans J.
  • Busi D.
  • Camenen Y.
  • Cardinali A.
  • Carli S.
  • Carnevale D.
  • Carpanese F.
  • Carpita M.
  • Casolari A.
  • Castaldo C.
  • Cavedon M.
  • Cazabonne J.
  • Cerovsky J.
  • Chapman-Oplopoiou B.
  • Chellai O.
  • Chervonyi Y.
  • Chlum J.
  • Chmielewski P.
  • Chomiczewska A.
  • Cicioni R.
  • Ciraolo G.
  • Classen I.
  • Clod A.
  • Coda S.
  • Colandrea C.
  • Contré C.E.
  • Coosemans R.
  • Cordaro L.
  • Cornelissen M.
  • Craciunescu T.
  • Cruz Zabala D.J.
  • Czarski M.
  • Davies I.
  • Dawson C.
  • de Tommasi G.
  • de Vylder B.
  • Decker J.
  • Derks G.L.
  • Devlaminck E.
  • Di Giannatale G.
  • Di Grazia L.E.
  • Ding R.
  • Donner C.
  • Dreval M.
  • Dritselis C.
  • Dubbioso S.
  • Ducker R.
  • Dunne M.
  • Durr-Legoupil-Nicoud G.
  • Duval B.P.
  • Édes L.
  • Ernst S.
  • Faitsch M.
  • Fan C.
  • Fasoli A.
  • Fedorczak N.
  • Felici F.
  • Ferron N.
  • Ficker O.
  • Figini L.
  • Figueiredo P.
  • Frank A.
  • Frassinetti L.
  • Frattolillo D.
  • Frigione D.
  • Furno I.
  • Février O.
  • Galassi D.
  • Galdon-Quiroga J.
  • Galeani S.
  • Galperti C.
  • Gambrioli M.
  • Garavaglia S.
  • Garcia Herreros S.
  • Garcia Munoz M.
  • Gaudio P.
  • Gelfusa M.
  • Genoud J.
  • Gerasimov S.
  • Gil L.
  • Giroud C.
  • Giroud-Garampon P.
  • Gobbin M.
  • Golfinopoulos T.
  • Goodman T.P.
  • Gorno S.
  • Grandin M.
  • Granucci G.
  • Graziano F.
  • Griener M.
  • Grzybicka N.
  • Guinchard S.
  • Hafner R.
  • Hakola A.
  • Halldestam P.
  • Ham C.
  • Hamel Ph.
  • Hamm D.
  • Heinrich P.
  • Heiß C.
  • Henderson S.
  • Hennequin P.
  • Hogge J.-P.
  • Hojlund R.
  • Honoré C.
  • Hoppe M.
  • Horacek J.
  • Huett E.
  • Innocente P.
  • Ivanov P.
  • Ivanov V.
  • Jackson T.
  • Jansen van Vuuren A.
  • Jardin A.
  • Jaspers R.
  • Jaulmes F.
  • Jensen T.
  • Jimenez Comez M.
  • Joffrin E.
  • Kabirov D.
  • Karpushov A.N.
  • Kasilov S.
  • Kazakov Y.
  • Kerboua-Benlarbi S.
  • Khan A.
  • King D.
  • Kirjasuo A.
  • Kivits E.M.M.
  • Kobussen S.
  • Koenders J.T.W.
  • Kohli P.
  • Kolsen de Wit J.
  • Kominis Y.
  • Kong M.
  • Kool B.
  • Kovacic J.
  • Kropackova D.
  • Krutkin O.
  • Kumar U.
  • Kwiatkowski R.
  • La Matina M.
  • Labit B.
  • Lafay A.
  • Laporta V.
  • Lazic N.
  • Lee K.
  • Lengyel F.
  • Lim K.
  • Linehan B.
  • Listopad A.
  • Lobko L.
  • Lonigro N.
  • Lunt T.
  • Mackenbach R.
  • Macusova E.
  • Maget P.
  • Malec S.
  • Mancini D.
  • Mantica P.
  • Marchetto C.
  • Marchioni S.
  • Mariani A.
  • Marin M.
  • Marinoni A.
  • Markl M.
  • Martin Y.
  • Martinelli L.
  • Masillo S.
  • Masocco R.
  • Masson V.
  • Mattei M.
  • Mattogno S.
  • Mazon D.
  • Mazzi S.
  • Mele A.
  • Menkovski V.
  • Merle A.
  • Michi A.
  • Mirowski R.
  • Misdanitis S.
  • Mishra R.
  • Moiraf D.
  • Molina-Cabrera P.A.
  • Molisani S.
  • Mombelli F.
  • Morgan R.I.
  • Moro A.
  • Murari A.
  • Murray K.
  • Muscente P.
  • Muzio I.
  • Mykytchuk D.
  • Nakeva Y.
  • Napoli F.
  • Nielsen A.H.
  • Nielsen S.K.
  • Norman T.
  • Nowak S.
  • Nyström H.
  • Ochoukov R.
  • Orduna-Martinez A.
  • Orlandi L.
  • Orrico C.
  • Orsitto F.P.
  • Osawa R.
  • Osborne N.
  • Oyola P.
  • Paduaru C.
  • Pajares A.
  • Palade D.I.
  • Pan O.
  • Panico O.
  • Papagiannis P.
  • Passoni M.
  • Pastore F.
  • Patel A.
  • Pau A.
  • Paz-Soldan C.
  • Pedersen A.C.
  • Pedrini M.
  • Pelka G.
  • Perek A.
  • Peres Asnis Y.
  • Perillo R.
  • Pesamosca F.
  • Petersen K.
  • Pigatto L.
  • Piron C.
  • Piron L.
  • Pironti A.
  • Plyusnin V.
  • Podesta M.
  • Poels Y.
  • Pokol G.I.
  • Poley J.
  • Pomârjanschi L.
  • Poradzinski M.
  • Porte L.
  • Possieri C.
  • Puentes del Pozo F.
  • Pueschel M.J.
  • Quadri V.
  • Rabinski M.
  • Ragona R.
  • Ratta G.A.
  • Rea C.
  • Reimerdes H.
  • Reisner M.
  • Reux C.
  • Ricci D.
  • Ricci P.
  • Riedmiller M.
  • Rienäcker S.
  • Rispoli N.
  • Rivero-Rodriguez J.F.
  • Rizkallah R.
  • Rodriguez Gonzalez A.
  • Romano F.
  • Rossi R.
  • Rud M.
  • Sales de Oliveira D.
  • Salewski M.
  • Salmi A.
  • Sauter O.
  • S Schmidt Bo
  • Schoonheere N.
  • Schutjes K.
  • Scotti L.
  • Senni L.
  • Senstius M.G.
  • Setzu S.
  • Sharapov S.E.
  • Sheikh U.A.
  • Sias G.
  • Silva Füglister M.
  • Silvagni D.
  • Simonetto A.
  • Simons L.
  • Singh L.
  • Singh K.
  • Sintre P.
  • Sipilä S.
  • So O.
  • Sommariva C.
  • Sozzi C.
  • Spagnolo S.
  • Stagni A.
  • Stollberg C.
  • Subba F.
  • Sun G.
  • Sun H.
  • Svantner J.
  • Tala T.
  • Tamain P.
  • Tanaka K.
  • Tang W.
  • Tema Biwole A.
  • Tenaglia A.
  • Terranova D.
  • Testa D.
  • Thome K.E.
  • Thrysoe A.
  • Tomes M.
  • Tonello E.
  • Topalova M.A.
  • Tracey B.
  • Tsitrone E.
  • Tsui C.K.
  • Tumbokon J.
  • Tunkl M.
  • Ugoletti M.
  • Valentini A.
  • Vallar M.
  • van Berkel M.
  • van Leeuwen L.
  • van Mulders S.
  • van Parys G.
  • van Rossem M.
  • Venturini C.
  • Verhaegh K.
  • Vermare L.
  • Vianello N.
  • Viezzer E.
  • Villard L.
  • Vincent B.
  • Vincent C.
  • Vincenzi P.
  • Vinklárek J.
  • Voitsekhovitch I.
  • Votta L.
  • Vu N.M.T.
  • Wang A.
  • Wang C.
  • Wang Y.
  • Wendler N.
  • Westerhof E.
  • Wiesen S.
  • Wijkamp T.
  • Winkel M.
  • Wüthrich C.
  • Wyss I.
  • Xiang L.
  • Xu G.
  • Yang H.
  • Zebrowski J.
  • Zestanakis P.A.
  • Zhang H.
  • Zimmermann C.F.B.
  • Zuin M.
  • Zurita M.
  Nuclear Fusion, IOP Publishing, 2026, 66 (11), pp.116007. Abstract Research on the Tokamak à Configuration Variable addresses a wide range of key questions relevant to ITER and future fusion power plants. Over the past two years, highly productive experimental campaigns have led to major advances across several areas: the ITER baseline scenario; pedestal properties in low-collisionality, peeling-limited conditions; and the development of high- β N , non-inductive regimes. Alternative high-confinement scenarios have likewise received significant attention, with remarkable progress in quasi-continuous exhaust operation, X-point radiator plasmas, and negative triangularity configurations. Substantial achievements were also made in the mitigation or benign termination of runaway electron beams, in elucidating fast-ion loss mechanisms, and in improving exhaust behaviour in both conventional and alternative divertor geometries. These experimental results have been strongly supported by advances in modelling and their direct application to the experiment, ranging from gyrokinetic simulations of core and pedestal turbulence to fluid-based studies of scrape-off layer and divertor physics in diverse geometries. Plasma control has taken on an increasingly important role, with model-based and data-driven approaches now closely intertwined with physics studies. This article provides a overview of these recent activities, together with a brief outlook on forthcoming upgrades and next steps. (10.1088/1741-4326/ae6d12)
  DOI : 10.1088/1741-4326/ae6d12
• Analyse du bilan (BGES) des activités spatiales du LPP
  
  • Rezeau Laurence
  • Sahraoui Fouad
  , 2026. L'outil GES 1point5 de Labos1point5 permet d'obtenir de manière simple un bilan des émissions de gaz à effet de serre associées aux activités de recherche effectuées hors du laboratoire, ce qui se résume pour le LPP essentiellement à l'exploitation des données des missions spatiales. Le résultat obtenu varie dans des proportions importantes d'une année sur l'autre, ce qui rend l'analyse compliquée puisque l'activité réelle de l'équipe n'est pas si variable. Nous analyserons comment ce résultat est lié à notre activité réelle. Nous comparerons la méthode de calcul, initiée par les collègues de l'IRAP, avec celle qui est utilisée pour les autres « grands instruments » dont les émissions sont prises en compte par Labos1point5. L'objectif de ces calculs de bilan est d'avoir un instrument pour évaluer les évolutions de l'impact de notre activité d'une année sur l'autre dans le but de tenter de diminuer cet impact sans dégrader la qualité de la science produite. Nous nous interrogerons sur ce qui est possible pour améliorer le « thermomètre » et le bilan des missions spatiales.
• Operational space exploration of the X-Point Radiator scenario in WEST
  
  • Rivals N
  • Fedorczak N
  • Geulin E
  • Nouailletas R
  • Moiraf D
  • Yang H
  • Havlickova E
  • Meng L
  • Guillemaut C
  • Gunn J P
  • Hennequin P
  • Morales J
  • Manas P
  • Fevre L
  • Gaspar J
  • Ekedahl A
  • Gerardin J
  • Corre Y
  • Maget P
  • Bernert M
  • Henderson S
  • Reimerdes H
  • Tsitrone E
  • Vianello N
  , 2026. Operational space exploration of the X-Point Radiator scenario in WEST
• Evidence of Langmuir/ Z -mode Wave Decay into Z -mode Electromagnetic Radiation in the Solar Wind
  
  • Polanco-Rodríguez F J
  • Krafft C.
  • Savoini P.
  The Astrophysical Journal Letters, Bristol : IOP Publishing, 2026, 1002 (2), pp.L35. The nonlinear decay of Langmuir/ Z -mode waves into electromagnetic Z -mode wave radiation near the plasma frequency is observed for the first time in the solar wind, during the encounter of the Solar Orbiter satellite with an electron beam associated with a type III radio burst. This result was achieved through the high-resolution electric and magnetic field measurements provided by the Radio Plasma Waves instrument on board the spacecraft. The decay process is identified through multiple lines of evidence: satisfaction of Doppler-shifted frequency resonance conditions, strong phase coherence and temporal coincidence between the interacting waves, dominance over competing mechanisms, and full agreement with theoretical predictions. Two-dimensional particle-in-cell simulations, conducted under close beam-plasma conditions, successfully reproduce the key features of the observations. Notably, they suggest that the wave packet observed by Solar Orbiter may be trapped within an extended, nearly flat-bottomed density well, where the decay process is not overcome by wave scattering on random density fluctuations and subsequent mode conversion effects. (10.3847/2041-8213/ae626f)
  DOI : 10.3847/2041-8213/ae626f
• 3D hybrid simulations of self-consistent IP shocks and their interaction with Earth
  
  • Cazzola Emanuele
  • Fontaine Dominique
  • Savoini Philippe
  , 2026. Interplanetary shocks are ubiquitous in the heliosphere in relation or not with solar events such as Stream Interaction Regions and Coronal Mass Ejections. However, their interactions with planetary environments remain poorly understood. In this study, we performed hybrid-PIC simulations of the interaction between interplanetary shocks and a realistic near-Earth environment system. We firstly focused on two aspects: (i) the self-consistent generation of a realistic bow shock–magnetosheath–magnetopause system, and (ii) a stand-alone analysis of the self-consistent evolution of a high-speed stream throughout an interplanetary medium in different scenarios. The latter included quasi-perpendicular, quasi-parallel, and Parker spiral-based scenarios, in order to highlight their profoundly diverse dynamics, as well as the possible formation of large upstream instabilities, such as foreshocks.Finally, we present preliminary findings on the interaction between the realistic near-Earth environment and an interplanetary shock-front and shock-sheath in a quasi-perpendicular scenario. (10.5194/egusphere-egu26-5366)
  DOI : 10.5194/egusphere-egu26-5366
• In-flight performance and first scientific observations of the Search-Coil Magnetometer (SCM) of the Radio and Plasma Waves Investigation (RPWI) onboard the ESA JUICE mission
  
  • Le Khanh T. N.
  • Retino Alessandro
  • Le Contel Olivier
  • Mansour Malik
  • Faure Thomas
  • Baraka Mohammed
  • Stassen Theo
  • Chust Thomas
  • Mirioni Laurent
  • Piberne Rodrigue
  • Santolik Ondrej
  • Soucek Jan
  • Pisa David
  • Khotyaintsev Yuri
  • Cecconi Baptiste
  • Wahlund Jan-Erik
  • Bergman Jan
  • Brown P.
  • Dougherty Michele
  • Masters Adam
  • Barabash S.
  , 2026. The JUpiter ICy moons Explorer (JUICE) mission is the first large-class (L1) mission of ESA Cosmic Vision. JUICE has been launched in April 2023 with an arrival at Jupiter in 2031 and at least four years making detailed plasma observations of Jupiter's magnetosphere and of three of its largest moons (Ganymede, Callisto and Europa). The Radio and Plasma Wave Investigation (RPWI) consortium will carry the most advanced set of electric and magnetic fields sensors ever flown in Jupiter's magnetosphere, which will allow to characterize the radio emission and plasma wave environment of Jupiter and its icy moons. The Search Coil Magnetometer (SCM) of RPWI, combined with the RPWI Low-Frequency receiver (LF), will provide for the first time three-dimensional measurements of magnetic field fluctuations within Jupiter's magnetosphere, with high sensitivity (~10 fT / √Hz at 1 kHz) in the frequency range 0.1 Hz - 20 kHz. Here we present SCM in-flight performance and first scientific observations obtained during its cruise phase, including those from the Lunar-Earth Gravity Assist (LEGA) in August 2024. These observations show a nominal functioning and performance of SCM, in agreement with ground calibrations, together with a rather good magnetic cleanliness of the JUICE spacecraft. Observations during LEGA have also allowed to properly identify a number of plasma boundaries in the Earth’s magnetosphere, such as the magnetopause and the magnetotail current sheet, successfully testing the SCM capability to study such boundaries at Jupiter’s and of Ganymede's magnetosphere. (10.5194/egusphere-egu26-21140)
  DOI : 10.5194/egusphere-egu26-21140
• Experiments and SOLEDGE modelling of X-Point Radiator regimes in WEST
  
  • Rivals N
  • Fedorczak N
  • Yang H
  • Fèvre L
  • Orlacchio F
  • Havlickova E
  • Team West
  , 2026. <div><p>Particle flux to divertor plate Plasma density "Detachment": reduction of particle flux "XPR": Stable toroidal radiation ring located at the X-Point, (= "stable MARFE"), observed in many machines, associated with divertor heat flux reduction Colloque FR-FCM -N.</p></div>
• Theoretical ion sputtering yields from loose powders using a multiscale Monte Carlo approach
  
  • Verkercke Sébastien
  • Berhanu Deborah
  • Bu Caixia
  • Clouter-Gergen Ben
  • Leblanc François
  • Lewis Jesse R
  • Morrissey Liam S
  • Savin Daniel W
  Journal of Applied Physics, American Institute of Physics, 2026, 139, pp.145302. Ion sputtering from loose powders remains poorly understood despite its relevance to planetary science and industry. We developed a multi-scale Monte Carlo model to simulate sputtering from powders, using a higher-fidelity approach for the target geometry compared to voxel-based methods. Simulating Kr+ ions impacting Cu powders and flat slabs, we show that sputtering from loose powders differs markedly from that of flat slabs or rough surfaces. The main differences are: (1) for incident angles α > 0° relative to the bulk normal, the escaping sputtering yield is dominated by backward-directed ejecta for all ion energies; (2) for α ≤ 60°, the yield peaks toward the ion-beam origin, similar to the opposition effect seen in optical observations of airless bodies; (3) the angular distribution peak is half or less than that of a flat slab as ion energy increases, no evolution occurs from primary to secondary knock-on sputtering in the ejecta angular distribution. We attribute these behaviors to the powder’s interconnected voids. Ions penetrate these voids and sputter underlying grains; the ejecta then preferentially escape toward the ion-beam origin, where shadowing is minimal. We derive two fitting functions: (1) relating the escaping sputtering yield of a powder to that of a flat surface, depending only on porosity, incident angle, mean local incidence angle, and the corresponding flat slab yield; (2) providing the double-differential angular distribution of the escaping ejecta for porosities ≥0.49. These provide a potentially universal fitting function of the absolute doubly differential escaping sputtering yield from loose powders. (10.1063/5.0316828)
  DOI : 10.1063/5.0316828
• Low‐Pressure Microwave Air Plasma Decontamination of Black Pepper ( Piper nigrum ): From Microbial Efficacy to Quality Preservation
  
  • Soulier Manon
  • Kais Abderrahmane
  • Maho Thomas
  • Guillot Philippe
  • Muja Cristina
  Plasma Processes and Polymers, Wiley-VCH Verlag, 2026, 23 (4). ABSTRACT This study investigates low‐pressure microwave air plasma as a non‐thermal decontamination approach for spices, using black peppercorns as a model matrix. At 20 Pa and 80 W, the discharge exhibits electron densities of 10 9 –10 10 cm −3 , effective electron temperatures of 0.7 eV, while keeping the substrate temperature below 60°C. Under these conditions 1.2‐log reduction of native aerobic mesophilic and thermophilic flora is achieved after 60 min. Bacillus subtilis spores on peppercorns show a similar 1.2‐log reduction, versus > 6‐log on flat glass carriers, revealing a strong surface shielding effect. UV radiation drives early spore inactivation, while long‐lived reactive species contribute during prolonged exposures. These antimicrobial effects are achieved without significant compromise of the key quality attributes of black pepper. (10.1002/ppap.70165)
  DOI : 10.1002/ppap.70165
• Photonic interactions with semiconducting barrier discharges
  
  • Taihi Ayah Soundous
  • Pai David Z
  Journal of Physics D: Applied Physics, IOP Publishing, 2026, 59 (13), pp.135203. Semiconducting Barrier Discharges (SeBDs) generate uniform ionization waves in air at atmospheric pressure. In this work, we investigate how externally applied irradiation synchronized with the discharge can mimic photoconductive-type coupling between the plasma and the semiconductor surface. By illuminating the Si–SiO2 interface with nanosecond pulsed irradiation at wavelengths from 532 nm to 1064 nm, and using fast imaging, optical emission spectroscopy, and current–voltage measurements, we show evidence that the photoexcitation of charge carriers in silicon enhances the plasma emission and increases the inferred reduced electric field, with no significant change in the electrical energy. The magnitude and thresholds of these responses depend on wavelength. By comparing the SeBD to a metal-oxide-semiconductor photodetector, this behavior can be explained by the absorption length. This length determines whether carriers are photogenerated inside the depletion region at the SiO2 –Si interface where they are efficiently separated and undergo impact ionization amplification, or deeper in the silicon bulk where carrier separation is weaker and free-carrier absorption diminishes the quantum efficiency. These results focus on the microscopic processes governing the plasma-semiconductor coupling and highlight how the optoelectronic properties of silicon can influence surface ionization waves. (10.1088/1361-6463/ae530a)
  DOI : 10.1088/1361-6463/ae530a
• White paper on the relevance of the European Solar Telescope (EST) for the French heliophysics community
  
  • Pariat Etienne
  • Noraz Quentin
  • Perri Barbara
  • Poirier Nicolas
  • Froment C.
  • Bigot Lionel
  • Aulanier Guillaume
  • Gelly Bernard
  • Aboudarham Jean
  • Aizawa Sae
  • Alexandrova Olga
  • Alqeeq Soboh
  • Amari Tahar
  • Auchère Frédéric
  • Bernoux Guillerme
  • Berthomier Matthieu
  • Bommier Veronique
  • Bonnin Xavier
  • Brun Allan Sacha
  • Bualé Isabelle
  • Buchlin Éric
  • Canou Aurélien
  • Canu Patrick
  • Corbard Thierry
  • Cornu Florence
  • Coustillet Camille
  • Cozzani Giulia
  • D’herbomez Léa
  • Diaz Castillo Saida
  • Dudok de Wit Thierry
  • Faurobert Marianne
  • Finley Adam
  • Fontaine Dominique
  • Garcia Rafael A.
  • Grappin Roland
  • Hadid Lina
  • Henadhira Arachchige Kalpa Harindra Perera
  • Janvier Miho
  • Jouve Laurène
  • Kieokaew Rungployphan
  • Kirkwood Hannah
  • Lavraud Benoit
  • Le Breton Jean-Pierre
  • Le Contel Olivier
  • Le Nestour Nicolas
  • Leblanc François
  • Masson Sophie
  • Meyer-Vernet Nicole
  • Parenti Susanna
  • Pitout Frédéric
  • Rieutord Michel
  • Romero Castañeda Jorge
  • Rouillard Alexis
  • Ruiz de Galarreta Claudia
  • Sahraoui Fouad
  • Schmieder Brigitte
  • Simon Pauline
  • Strugarek Antoine
  • Tallon Michel
  • Thepthong Panisara
  • Touresse Jade
  • Vial Jean-Claude
  • Vilmer Nicole
  • Zaslavsky Arnaud
  , 2026. The project of the European Solar Telescope aims to provide a state-of-the art infrastructure to study the Sun and its interactions with Earth and the heliosphere. This 4.2m aperture telescope will be equipped with multi conjugate adaptive optics, light-polarisation analyser, imaging spectrograph and integral field unit spectrographs. It will provide unprecedented observations of the solar photosphere and chromosphere and of the dynamical events and features that pertains to the low solar atmosphere. The EST project is presently in a phase of crystallisation, aiming at the creation of an European Research Infrastructure Consortium. While the French community has continuously been associated with the development of the EST project, some specific scientific aspects are more particularly relevant for the French astrophysics and heliophysics communities. The present review highlights the scientific research axes of high interest from the French community that shall strongly benefit from EST. The later will not only advance numerous topics of solar physics, as well as solar adaptive optics developments, but will also provide unrivaled datasets of high interest in the framework of space weather. This review also aims to highlight the space weather use that can be done with future EST observations, that will be particularly relevant for French heliophysicists.
• A survey on performance evaluations in time-dependent Petri nets
  
  • Fanti Maria Pia
  • Liu Ruotian
  • Zhang Shu
  • He Zhou
  • Lefebvre Dimitri
  Discrete Event Dynamic Systems, Springer Verlag, 2026, 36 (1), pp.13. Abstract Time-dependent Petri nets extend the classical Petri net formalism by incorporating timing constraints, enabling the modeling and analysis of temporal behavior in discrete event systems. This survey provides a comprehensive overview of the foundational concepts and major classes of time-dependent Petri nets, including both deterministic and stochastic variants. We explore their modeling capabilities, formal analysis techniques, and a range of performance evaluation methods. In particular, we aim to analyze the performance indices such as cycle time, throughput, and resource utilization, which are critical for assessing system efficiency and scalability. Examples are provided to demonstrate how system performance is evaluated. Additionally, we discuss current challenges and emerging trends in the field, highlighting open research problems and potential future directions. (10.1007/s10626-026-00435-y)
  DOI : 10.1007/s10626-026-00435-y
• Plasma-Interface Coupling in Semiconducting Barrier Discharges
  
  • Taihi Ayah Soundous
  , 2026. This dissertation investigates Semiconducting BarrierDischarges (SeBDs), an alternative to Dielectric Barrier Discharges (DBDs), capable of generating more homogeneous and energetic atmospheric plasmas.The experiments were carried out on Si-SiO2 substrates using nano second pulses. The air plasma was analyzed through fast imaging, electrical measurements, and optical emission spectroscopy. The study explores the plasma-SiO2-Si interface coupling through an analogy with a MOS structure operating in the strong inversion regime.First, irradiation of the Si-SiO2 interface increases both plasma emission and electric field, particularly at shorter wavelengths. Two interaction mechanisms were identified : a depletion-region mechanism with efficient carrier separation and impact ionization amplification, and a bulk mechanism associated with re-duced quantum efficiency due to free-carrier absorption. In addition, the study of silicon doping showed that intermediate levels promote discharge extensionthrough a balance between carrier recombination,mobility, and interfacial electric field. In contrast, intrinsic silicon deforms the SeBD due to its insufficient carrier density to screen surface charges. Finally, repetition frequency, pulse shape and polarity strongly influence SeBD extent and homogeneity through memory effects related to surface charges, carrier dynamics in silicon, and depletion region formation.In conclusion, this work highlights the central role ofphotonic and electric field mechanisms in plasma-semiconductor coupling. Optimizing material properties and electrical parameters enables improved control of SeBD propagation, uniformity, and energy,opening the way for new plasma devices based on the optoelectronic properties of semiconductors.
• Magnetic geometry impact on the edge radial electric field in tokamaks
  
  • Rienäcker Sascha
  , 2026. Mitigating plasma turbulence is a major objective of magnetic confinement fusion research,as the resulting transport of heat and particles largely determines confinement quality—and thus, the performance and cost of future fusion power plants.Sheared plasma flows play a central role in regulating turbulent transport, enabling, in particular, the formation of transport barriers associated with high confine-ment regimes. Even in low confinement mode (L-mode), tokamak plasmas typically exhibit, at the edge of the confined region, a narrow Er × B shear layer corresponding to a negative radial electric field (Er)“well”. However, a deep understanding of the role ofthis Er well in setting L-mode confinement proper-ties and in providing access to higher confinement regimes is still lacking. In addition, the sensitivities of Erto plasma conditions remain poorly understood and difficult to capture using existing models or numerical tools. This PhD thesis investigates these sensitivities experimentally to help disentangle the dominant Er drives in L-mode and clarify their role in confinement improvement or transitions. Experiments are primarily conducted on the TCV tokamak, using a newlyinstalled Doppler backscattering (DBS) diagnostic to characterize the edge Er profile. Systematic parameterscans are performed in carefully matched dischargesto isolate the impact of magnetic drift configuration and plasma shaping (specifically, triangularity) on the mean Er and other edge profiles. Overall, the findings support a link between edge Er shear and the influence of magnetic geometry on confinement properties.Combined with recent first-principles simulations, the observations point to the importance of turbulence-driven flow generation in explaining sensitivities of Erto magnetic geometry.
• Comparative physicochemical study of dielectric barrier discharge and post-discharge plasmas to treat non-small cell lung carcinoma in murine models
  
  • Soulier Manon
  • Marmier Solenne
  • Decauchy Henri
  • Cremer Isabelle
  • Dufour Thierry
  Journal of Physics D: Applied Physics, IOP Publishing, 2026, 59 (9), pp.095202. While cold atmospheric plasmas (CAPs) are increasingly explored for cancer therapy, it remains unclear how distinct device configurations translate into differences in tissue coupling, safety, and therapeutic efficacy. To address this gap, a comparative evaluation of the two following CAP sources has been conducted: the ORJET (atmospheric pressure plasma jet in outer ring electrode configuration) and the PoDBD (post-discharge delivered by a dielectric barrier device with a grounded-mesh electrode). Electrical behavior is quantified on an equivalent electrical human body model, while optical emission spectroscopy and surface-oxidation assays are achieved on transdermal membranes and polyethylene substrates to characterize the nature and diffusion of plasma-generated reactive species. Thermal safety is examined in mice through real-time temperature monitoring and histological analysis while antitumor efficacy is determined in a syngeneic model of non-small cell lung cancer (NSCLC) treated five times. The two devices display fundamentally different modes of tissue coupling: ORJET delivers localized interfacial electric field while PoDBD exposes tissue solely to reactive oxygen and nitrogen species-rich post-discharge. Despite these differences, both generate similar reactive-species signatures, preserve tissue integrity when operated within safe thermal limits, and significantly slow tumor progression compared with controls, with no difference between devices. These findings indicate that therapeutic activity arises predominantly from reactive-species chemistry rather than electrical coupling, supporting the applicability of diverse CAP technologies for oncological treatment. (10.1088/1361-6463/ae46ac)
  DOI : 10.1088/1361-6463/ae46ac
• A study of the magnetic effects of the Equatorial Electrojet (EEJ) along the East Asian and West African sectors
  
  • Grodji F.O.
  • Yao H.F.M.
  • Amaechi P.O.
  • Amory-Mazaudier C.
  • Doumbia V.
  • Kouassi N.
  • Kassamba A.A.
  • Tuo Z.
  Advances in Space Research, Elsevier, 2026. This paper presents a comparative analysis of the Equatorial Electrojet (EEJ) effects along the East Asian (140° E) and West African (5° W) sectors using geomagnetic field data recorded in 1993. The data were obtained within the frameworks of the International Equatorial Electrojet Year (IEEY) campaign for West Africa and the Solar-Terrestrial Energy Program (STEP) project for the Asian sector. The analysis was conducted under quiet magnetic conditions (Am < 20 nT) to facilitate the investigation of regular daily variations () induced by the EEJ. Key electrodynamic parameters of the EEJ such as ribbon width, center position, and maximum current intensity were estimated using latitudinal profiles of the H and Z components of the geomagnetic field. The results reveal significant latitudinal and longitudinal variations characterized by a wider EEJ ribbon in Asia (∼714 km) compared to West Africa (∼601 km), and a higher peak current intensity in West Africa (214.3 ± 30.9 A/km) relative to Asia (142.4 ± 31.9 A/km). Also, in 1993, the EEJ centre was located north of the magnetic equator in West Africa and south of it in Asia, indicating a pronounced hemispheric asymmetry. Seasonal variations show higher EEJ intensities during the equinoxes than during the solstices in both longitude sectors. Throughout 1993, the EEJ peak intensity over West Africa consistently surpassed that over East Asia, irrespective of the magnetic season. Furthermore, the frequency of occurrence of the counter-electrojet (CEJ) was higher in West Africa, especially during the morning hours. This study shows that EEJ morphology and strength are modulated by longitude-dependent factors, including ionospheric conductivity, neutral winds, atmospheric tides, and the geomagnetic field. (10.1016/j.asr.2026.03.039)
  DOI : 10.1016/j.asr.2026.03.039
• Foundations of plasma-assisted combustion: II. Mechanisms and applications
  
  • Laux C
  • Perrin-Terrin J-B
  • Lafaurie V
  • Starikovskaia S
  Plasma Sources Science and Technology, IOP Publishing, 2026, 35 (2), pp.023002. Abstract In Part 1 of this topical review, we introduced the main concepts and the basic principles of combustion and plasmas. Part 2 will now examine the topic of plasma-assisted combustion (PAC) with an emphasis on applications to novel combustion systems, particularly those of importance for the energy transition. We start by providing an overview of laboratory experiments that have helped unveil the main fundamental mechanisms of PAC. We also describe some of the main advances achieved in numerical simulations of these rich and complex phenomena in three dimensional, turbulent flames. We then review applications of PAC to practical combustion systems representative of industrial configurations, emphasizing flame stabilization, lean blow-off limit extension, thermo-acoustic instability control, supersonic combustion and plasma detonation engines. Special attention is paid to the reduction of pollutants and the optimization of plasma power. (10.1088/1361-6595/ae0f0f)
  DOI : 10.1088/1361-6595/ae0f0f
• Foundations of plasma-assisted combustion: I. Fundamentals of combustion and plasma
  
  • Starikovskaia S
  • Lafaurie V
  • Perrin-Terrin J-B
  • Laux C
  Plasma Sources Science and Technology, IOP Publishing, 2026, 35 (2), pp.023001. The use of plasma as an innovative solution to enhance combustion has been the focus of intense research for the past two decades. Plasma-assisted ignition and combustion has emerged as a potential solution for numerous industrial applications. This Foundation paper consists of two parts. Part 1 introduces the context and is followed by a brief summary of the reviews done over the last two decades to show the continued relevance of the topic. We then focus on the fundamentals of combustion and introduce the main concepts of the field. In particular, we discuss combustion kinetics, flame propagation modes, and numerical modeling. Following this, a more in-depth description of plasma physics, specifically non-equilibrium plasma, is provided. As in the previous section, the main concepts are highlighted and defined. We discuss electron energy distribution functions, electron-impact cross-sections, and reaction rates, with a focus on dissociation and fast gas heating which are of particular relevance in the field of plasma-assisted combustion. Finally, elements of numerical modeling are provided. Part 2 of the article will describe the topic of plasma-assisted combustion from the description of fundamental mechanisms to novel combustion systems of importance for the energy transition. (10.1088/1361-6595/ae3a17)
  DOI : 10.1088/1361-6595/ae3a17
• From electroculture to plasma agriculture: a three-century arc bridging Bertholon’s legacy with contemporary farming advances
  
  • Dufour Thierry
  Comptes Rendus. Mécanique, Académie des sciences (Paris), 2026, 354 (G1), pp.89-116. This review traces the historical trajectory of electricity in agriculture, from the earliest observations of electrical phenomena to the emergence of cold plasmas. Looking back to Antiquity and then to the Enlightenment, it underlines Abbé Bertholon’s 18th-century efforts to channel atmospheric electricity to stimulate crops, using devices such as the electro-végétomètre. Although these early electroculture experiments relied on neither quantitative dosimetry nor rigorous methodology, they foreshadowed the idea of a controlled transfer of electrical energy to plants. Then the review examines the historical development of galvanism, electrochemistry, and the physics of gaseous discharges throughout the 19th and 20th centuries, which collectively laid the foundations for contemporary cold-plasma technologies. In the 21st century, plasma agriculture has emerged as an interdisciplinary approach integrating electrical, chemical, radiative, thermal, and fluid-mechanical effects. Applications include seed treatment (preconditioning, seed priming), stimulation of plant growth, soil and water treatment, and decontamination of agri-food products. The review thus reassesses Abbé Bertholon’s contributions as those of a methodological precursor and shows how his intuition of a “vivifying electricity” resonates with modern cold-plasma science. Finally, it argues that plasma agriculture can transform an Enlightenment intuition into a reproducible experimental framework for sustainable agriculture and food safety. (10.5802/crmeca.331)
  DOI : 10.5802/crmeca.331
• Active chromospheric fibril singularity
  
  • Joshi Reetika
  • Rouppe van der Voort Luc
  • Aulanier Guillaume
  • Danilovic Sanja
  • Prasad Avijeet
  • Díaz Baso Carlos
  • Nóbrega-Siverio Daniel
  • Poirier Nicolas
  • Calchetti Daniele
  Astronomy & Astrophysics - A&A, EDP Sciences, 2026, 706, pp.A369. Context. The fine structures of the solar chromosphere, driven by photospheric motions, play a crucial role in the dynamics of solar magnetic fields. Many such structures have already been identified, such as fibrils, filament feet, and arch filament systems. Nevertheless, high-resolution observations show a wealth of structures whose nature remains elusive. Aims. We observed a puzzling, unprecedented chromospheric fibril singularity in the close vicinity of a blow-out solar jet and a flaring loop. We aim to understand the magnetic nature of this singularity and the cause of its activity using coordinated high-resolution, multi-wavelength observations. Methods. We aligned datasets from Solar Orbiter, SST, IRIS, and SDO. We re-projected the Solar Orbiter datasets to match the perspective of the Earth-based instruments and performed potential field extrapolations from Solar Orbiter/PHI data. We analysed the spatial and temporal evolution of the plasma structures and their link with the surface magnetic field. This led us to derive a model and scenario for the observed structures, which we explain in a general schematic representation. Results. We have discovered a new feature: a singularity in the chromospheric fibril pattern. It forms in a weak magnetic-field corridor between two flux concentrations of equal sign, at the base of a vertically inverted-Y-shaped field-line pattern. In this specific case, some activity develops along the structure: first, a flaring loop at one end, and second, a blow-out jet at the other end, where a coronal null point was present and associated with a chromospheric saddle point located on the fibril singularity. The observations suggest that both active phenomena are initiated by converging photospheric moat flows that exert pressure on this fibril singularity. (10.1051/0004-6361/202556666)
  DOI : 10.1051/0004-6361/202556666
• Reactive oxygen species trigger downward vertical migration in diatom microphytobenthic biofilms as a strategy to cope with oxidative stress
  
  • Desparmet Alexandre
  • Jesus Bruno
  • Robinet Tony
  • Dufour Thierry
  • Hubas Cédric
  The International Society of Microbiologial Ecology Journal, Nature Publishing Group, 2026, 20. Diatom-dominated intertidal microphytobenthic biofilms experience daily fluctuations in irradiance, which can lead to oxidative stress within the photosynthetic apparatus through the production and accumulation of reactive oxygen species. To maintain photosynthetic efficiency, benthic diatoms have developed protective strategies, including mobilization of the antioxidant xanthophyll cycle and the ability to migrate vertically through sediments. However, mechanistic understanding of signaling pathways underlying migration remains poorly characterized. This study investigated the triggering effect of reactive oxygen species on behavioral and photophysiological responses through the analysis of lipophilic pigments and fluorescence parameters. To this end, two microphytobenthic communities, one with sediment allowing vertical migration and another without sediment restricting it, were exposed to irradiance, cold atmospheric plasma, and hydrogen peroxide stresses. Results showed a consistent downward migration response under all oxidative stresses, highlighting the key role of reactive oxygen species, especially hydrogen peroxide, in triggering this microphytobenthic behavior. Moreover, a difference was observed between the pathways involved in vertical migration and those underlying photoprotective responses. Hydrogen peroxide and cold atmospheric plasma stresses highlighted the necessity for substantial microphytobenthic migration, whereas irradiance induced a specific and controlled response involving engagement of the xanthophyll cycle, acting in synergy with the migration strategy by showing stronger activation when migration was impaired. By establishing that a rapid and efficient migration could be induced by reactive oxygen species (ROS) and could act in synergy with the xanthophyll cycle in epipelic cells, this study provides key insights into the molecular basis of microphytobenthic responses to cellular and environmental oxidative stresses. (10.1093/ismejo/wrag034)
  DOI : 10.1093/ismejo/wrag034
• Flux rope formation through flux cancellation of sheared coronal arcades in a 3D convectively driven MHD simulation
  
  • Furuseth S.
  • Aulanier Guillaume
  Astronomy & Astrophysics - A&A, EDP Sciences, 2026, 706, pp.A350. Context. Space weather and its potential negative consequences for life on Earth have received increasing scientific attention in recent decades. In particular, predicting the onset of coronal mass ejections (CMEs) has become important from a security perspective. To predict CMEs, one must first understand the dynamics leading to preeruptive magnetic field configurations, which in many theories include a flux rope. Aims. In this study, we investigate the realistic formation of coronal flux ropes above the solar photosphere. The aim is to find out if and how flux ropes can form there, and how the formation is related to flux cancellation at the photosphere. Previously, such formation has been shown in smooth boundary-driven line-tied simulations and in idealized non-convective and symmetric flux-emergence simulations. Methods. We ran a convective nonsymmetric 3D radiative magnetohydrodynamic (MHD) simulation with the code Bifrost . Within the simulation box of 24 Mm × 24 Mm horizontal extent, a linear force-free field with sheared coronal arcades was slowly inserted. Following the insertion, the self-consistent stochastic plasma flows of the convection zone drove several small-scale flux cancellations and magnetic reconnection, without external influence. Lagrangian markers called corks were used to track the dynamic evolution of the magnetic field. Results. Over a period of 2.5 h, a flux rope was generated with photospheric footpoints separated by up to 12 Mm. The flux rope was gradually formed through several individual events, such as slipping reconnection, U-loop emergence, and thick-photosphere tether-cutting reconnection. Conclusions. Flux ropes, which can lead to CMEs, can be formed in the solar atmosphere solely driven by convection and flux cancellations at the photosphere. However, not all flux cancellations contribute to the buildup of the flux rope, and some coronal reconnection events that do are not clearly related to flux cancellation. The formation process of flux ropes from coronal sheared arcades driven by convection is therefore more complex than in the original smooth flux cancellation model. However, the end result is qualitatively the same. Flux cancellation works. A flux rope is formed. (10.1051/0004-6361/202554242)
  DOI : 10.1051/0004-6361/202554242